Index: head/sys/contrib/zstd/CHANGELOG =================================================================== --- head/sys/contrib/zstd/CHANGELOG (revision 354776) +++ head/sys/contrib/zstd/CHANGELOG (revision 354777) @@ -1,497 +1,528 @@ +v1.4.4 +perf: Improved decompression speed, by > 10%, by @terrelln +perf: Better compression speed when re-using a context, by @felixhandte +perf: Fix compression ratio when compressing large files with small dictionary, by @senhuang42 +perf: zstd reference encoder can generate RLE blocks, by @bimbashrestha +perf: minor generic speed optimization, by @davidbolvansky +api: new ability to extract sequences from the parser for analysis, by @bimbashrestha +api: fixed decoding of magic-less frames, by @terrelln +api: fixed ZSTD_initCStream_advanced() performance with fast modes, reported by @QrczakMK +cli: Named pipes support, by @bimbashrestha +cli: short tar's extension support, by @stokito +cli: command --output-dir-flat= , generates target files into requested directory, by @senhuang42 +cli: commands --stream-size=# and --size-hint=#, by @nmagerko +cli: command --exclude-compressed, by @shashank0791 +cli: faster `-t` test mode +cli: improved some error messages, by @vangyzen +cli: rare deadlock condition within dictionary builder, by @terrelln +build: single-file decoder with emscripten compilation script, by @cwoffenden +build: fixed zlibWrapper compilation on Visual Studio, reported by @bluenlive +build: fixed deprecation warning for certain gcc version, reported by @jasonma163 +build: fix compilation on old gcc versions, by @cemeyer +build: improved installation directories for cmake script, by Dmitri Shubin +pack: modified pkgconfig, for better integration into openwrt, requested by @neheb +misc: Improved documentation : ZSTD_CLEVEL, DYNAMIC_BMI2, ZSTD_CDict, function deprecation, zstd format +misc: fixed educational decoder : accept larger literals section, and removed UNALIGNED() macro + +v1.4.3 +bug: Fix Dictionary Compression Ratio Regression by @cyan4973 (#1709) +bug: Fix Buffer Overflow in legacy v0.3 decompression by @felixhandte (#1722) +build: Add support for IAR C/C++ Compiler for Arm by @joseph0918 (#1705) + v1.4.2 bug: Fix bug in zstd-0.5 decoder by @terrelln (#1696) bug: Fix seekable decompression in-memory API by @iburinoc (#1695) misc: Validate blocks are smaller than size limit by @vivekmg (#1685) misc: Restructure source files by @ephiepark (#1679) v1.4.1 bug: Fix data corruption in niche use cases by @terrelln (#1659) bug: Fuzz legacy modes, fix uncovered bugs by @terrelln (#1593, #1594, #1595) bug: Fix out of bounds read by @terrelln (#1590) perf: Improve decode speed by ~7% @mgrice (#1668) perf: Slightly improved compression ratio of level 3 and 4 (ZSTD_dfast) by @cyan4973 (#1681) perf: Slightly faster compression speed when re-using a context by @cyan4973 (#1658) perf: Improve compression ratio for small windowLog by @cyan4973 (#1624) perf: Faster compression speed in high compression mode for repetitive data by @terrelln (#1635) api: Add parameter to generate smaller dictionaries by @tyler-tran (#1656) cli: Recognize symlinks when built in C99 mode by @felixhandte (#1640) cli: Expose cpu load indicator for each file on -vv mode by @ephiepark (#1631) cli: Restrict read permissions on destination files by @chungy (#1644) cli: zstdgrep: handle -f flag by @felixhandte (#1618) cli: zstdcat: follow symlinks by @vejnar (#1604) doc: Remove extra size limit on compressed blocks by @felixhandte (#1689) doc: Fix typo by @yk-tanigawa (#1633) doc: Improve documentation on streaming buffer sizes by @cyan4973 (#1629) build: CMake: support building with LZ4 @leeyoung624 (#1626) build: CMake: install zstdless and zstdgrep by @leeyoung624 (#1647) build: CMake: respect existing uninstall target by @j301scott (#1619) build: Make: skip multithread tests when built without support by @michaelforney (#1620) build: Make: Fix examples/ test target by @sjnam (#1603) build: Meson: rename options out of deprecated namespace by @lzutao (#1665) build: Meson: fix build by @lzutao (#1602) build: Visual Studio: don't export symbols in static lib by @scharan (#1650) build: Visual Studio: fix linking by @absotively (#1639) build: Fix MinGW-W64 build by @myzhang1029 (#1600) misc: Expand decodecorpus coverage by @ephiepark (#1664) v1.4.0 perf: Improve level 1 compression speed in most scenarios by 6% by @gbtucker and @terrelln api: Move the advanced API, including all functions in the staging section, to the stable section api: Make ZSTD_e_flush and ZSTD_e_end block for maximum forward progress api: Rename ZSTD_CCtxParam_getParameter to ZSTD_CCtxParams_getParameter api: Rename ZSTD_CCtxParam_setParameter to ZSTD_CCtxParams_setParameter api: Don't export ZSTDMT functions from the shared library by default api: Require ZSTD_MULTITHREAD to be defined to use ZSTDMT api: Add ZSTD_decompressBound() to provide an upper bound on decompressed size by @shakeelrao api: Fix ZSTD_decompressDCtx() corner cases with a dictionary api: Move ZSTD_getDictID_*() functions to the stable section api: Add ZSTD_c_literalCompressionMode flag to enable or disable literal compression by @terrelln api: Allow compression parameters to be set when a dictionary is used api: Allow setting parameters before or after ZSTD_CCtx_loadDictionary() is called api: Fix ZSTD_estimateCStreamSize_usingCCtxParams() api: Setting ZSTD_d_maxWindowLog to 0 means use the default cli: Ensure that a dictionary is not used to compress itself by @shakeelrao cli: Add --[no-]compress-literals flag to enable or disable literal compression doc: Update the examples to use the advanced API doc: Explain how to transition from old streaming functions to the advanced API in the header build: Improve the Windows release packages build: Improve CMake build by @hjmjohnson build: Build fixes for FreeBSD by @lwhsu build: Remove redundant warnings by @thatsafunnyname build: Fix tests on OpenBSD by @bket build: Extend fuzzer build system to work with the new clang engine build: CMake now creates the libzstd.so.1 symlink build: Improve Menson build by @lzutao misc: Fix symbolic link detection on FreeBSD misc: Use physical core count for -T0 on FreeBSD by @cemeyer misc: Fix zstd --list on truncated files by @kostmo misc: Improve logging in debug mode by @felixhandte misc: Add CirrusCI tests by @lwhsu misc: Optimize dictionary memory usage in corner cases misc: Improve the dictionary builder on small or homogeneous data misc: Fix spelling across the repo by @jsoref v1.3.8 perf: better decompression speed on large files (+7%) and cold dictionaries (+15%) perf: slightly better compression ratio at high compression modes api : finalized advanced API, last stage before "stable" status api : new --rsyncable mode, by @terrelln api : support decompression of empty frames into NULL (used to be an error) (#1385) build: new set of macros to build a minimal size decoder, by @felixhandte build: fix compilation on MIPS32, reported by @clbr (#1441) build: fix compilation with multiple -arch flags, by @ryandesign build: highly upgraded meson build, by @lzutao build: improved buck support, by @obelisk build: fix cmake script : can create debug build, by @pitrou build: Makefile : grep works on both colored consoles and systems without color support build: fixed zstd-pgo, by @bmwiedemann cli : support ZSTD_CLEVEL environment variable, by @yijinfb (#1423) cli : --no-progress flag, preserving final summary (#1371), by @terrelln cli : ensure destination file is not source file (#1422) cli : clearer error messages, especially when input file not present doc : clarified zstd_compression_format.md, by @ulikunitz misc: fixed zstdgrep, returns 1 on failure, by @lzutao misc: NEWS renamed as CHANGELOG, in accordance with fboss v1.3.7 perf: slightly better decompression speed on clang (depending on hardware target) fix : performance of dictionary compression for small input < 4 KB at levels 9 and 10 build: no longer build backtrace by default in release mode; restrict further automatic mode build: control backtrace support through build macro BACKTRACE misc: added man pages for zstdless and zstdgrep, by @samrussell v1.3.6 perf: much faster dictionary builder, by @jenniferliu perf: faster dictionary compression on small data when using multiple contexts, by @felixhandte perf: faster dictionary decompression when using a very large number of dictionaries simultaneously cli : fix : does no longer overwrite destination when source does not exist (#1082) cli : new command --adapt, for automatic compression level adaptation api : fix : block api can be streamed with > 4 GB, reported by @catid api : reduced ZSTD_DDict size by 2 KB api : minimum negative compression level is defined, and can be queried using ZSTD_minCLevel(). build: support Haiku target, by @korli build: Read Legacy format is limited to v0.5+ by default. Can be changed at compile time with macro ZSTD_LEGACY_SUPPORT. doc : zstd_compression_format.md updated to match wording in IETF RFC 8478 misc: tests/paramgrill, a parameter optimizer, by @GeorgeLu97 v1.3.5 perf: much faster dictionary compression, by @felixhandte perf: small quality improvement for dictionary generation, by @terrelln perf: slightly improved high compression levels (notably level 19) mem : automatic memory release for long duration contexts cli : fix : overlapLog can be manually set cli : fix : decoding invalid lz4 frames api : fix : performance degradation for dictionary compression when using advanced API, by @terrelln api : change : clarify ZSTD_CCtx_reset() vs ZSTD_CCtx_resetParameters(), by @terrelln build: select custom libzstd scope through control macros, by @GeorgeLu97 build: OpenBSD patch, by @bket build: make and make all are compatible with -j doc : clarify zstd_compression_format.md, updated for IETF RFC process misc: pzstd compatible with reproducible compilation, by @lamby v1.3.4 perf: faster speed (especially decoding speed) on recent cpus (haswell+) perf: much better performance associating --long with multi-threading, by @terrelln perf: better compression at levels 13-15 cli : asynchronous compression by default, for faster experience (use --single-thread for former behavior) cli : smoother status report in multi-threading mode cli : added command --fast=#, for faster compression modes cli : fix crash when not overwriting existing files, by Pádraig Brady (@pixelb) api : `nbThreads` becomes `nbWorkers` : 1 triggers asynchronous mode api : compression levels can be negative, for even more speed api : ZSTD_getFrameProgression() : get precise progress status of ZSTDMT anytime api : ZSTDMT can accept new compression parameters during compression api : implemented all advanced dictionary decompression prototypes build: improved meson recipe, by Shawn Landden (@shawnl) build: VS2017 scripts, by @HaydnTrigg misc: all /contrib projects fixed misc: added /contrib/docker script by @gyscos v1.3.3 perf: faster zstd_opt strategy (levels 16-19) fix : bug #944 : multithreading with shared ditionary and large data, reported by @gsliepen cli : fix : content size written in header by default cli : fix : improved LZ4 format support, by @felixhandte cli : new : hidden command `-S`, to benchmark multiple files while generating one result per file api : fix : support large skippable frames, by @terrelln api : fix : streaming interface was adding a useless 3-bytes null block to small frames api : change : when setting `pledgedSrcSize`, use `ZSTD_CONTENTSIZE_UNKNOWN` macro value to mean "unknown" build: fix : compilation under rhel6 and centos6, reported by @pixelb build: added `check` target v1.3.2 new : long range mode, using --long command, by Stella Lau (@stellamplau) new : ability to generate and decode magicless frames (#591) changed : maximum nb of threads reduced to 200, to avoid address space exhaustion in 32-bits mode fix : multi-threading compression works with custom allocators fix : ZSTD_sizeof_CStream() was over-evaluating memory usage fix : a rare compression bug when compression generates very large distances and bunch of other conditions (only possible at --ultra -22) fix : 32-bits build can now decode large offsets (levels 21+) cli : added LZ4 frame support by default, by Felix Handte (@felixhandte) cli : improved --list output cli : new : can split input file for dictionary training, using command -B# cli : new : clean operation artefact on Ctrl-C interruption cli : fix : do not change /dev/null permissions when using command -t with root access, reported by @mike155 (#851) cli : fix : write file size in header in multiple-files mode api : added macro ZSTD_COMPRESSBOUND() for static allocation api : experimental : new advanced decompression API api : fix : sizeof_CCtx() used to over-estimate build: fix : no-multithread variant compiles without pool.c dependency, reported by Mitchell Blank Jr (@mitchblank) (#819) build: better compatibility with reproducible builds, by Bernhard M. Wiedemann (@bmwiedemann) (#818) example : added streaming_memory_usage license : changed /examples license to BSD + GPLv2 license : fix a few header files to reflect new license (#825) v1.3.1 New license : BSD + GPLv2 perf: substantially decreased memory usage in Multi-threading mode, thanks to reports by Tino Reichardt (@mcmilk) perf: Multi-threading supports up to 256 threads. Cap at 256 when more are requested (#760) cli : improved and fixed --list command, by @ib (#772) cli : command -vV to list supported formats, by @ib (#771) build : fixed binary variants, reported by @svenha (#788) build : fix Visual compilation for non x86/x64 targets, reported by Greg Slazinski (@GregSlazinski) (#718) API exp : breaking change : ZSTD_getframeHeader() provides more information API exp : breaking change : pinned down values of error codes doc : fixed huffman example, by Ulrich Kunitz (@ulikunitz) new : contrib/adaptive-compression, I/O driven compression strength, by Paul Cruz (@paulcruz74) new : contrib/long_distance_matching, statistics by Stella Lau (@stellamplau) updated : contrib/linux-kernel, by Nick Terrell (@terrelln) v1.3.0 cli : new : `--list` command, by Paul Cruz cli : changed : xz/lzma support enabled by default cli : changed : `-t *` continue processing list after a decompression error API : added : ZSTD_versionString() API : promoted to stable status : ZSTD_getFrameContentSize(), by Sean Purcell API exp : new advanced API : ZSTD_compress_generic(), ZSTD_CCtx_setParameter() API exp : new : API for static or external allocation : ZSTD_initStatic?Ctx() API exp : added : ZSTD_decompressBegin_usingDDict(), requested by Guy Riddle (#700) API exp : clarified memory estimation / measurement functions. API exp : changed : strongest strategy renamed ZSTD_btultra, fastest strategy ZSTD_fast set to 1 tools : decodecorpus can generate random dictionary-compressed samples, by Paul Cruz new : contrib/seekable_format, demo and API, by Sean Purcell changed : contrib/linux-kernel, updated version and license, by Nick Terrell v1.2.0 cli : changed : Multithreading enabled by default (use target zstd-nomt or HAVE_THREAD=0 to disable) cli : new : command -T0 means "detect and use nb of cores", by Sean Purcell cli : new : zstdmt symlink hardwired to `zstd -T0` cli : new : command --threads=# (#671) cli : changed : cover dictionary builder by default, for improved quality, by Nick Terrell cli : new : commands --train-cover and --train-legacy, to select dictionary algorithm and parameters cli : experimental targets `zstd4` and `xzstd4`, with support for lz4 format, by Sean Purcell cli : fix : does not output compressed data on console cli : fix : ignore symbolic links unless --force specified, API : breaking change : ZSTD_createCDict_advanced(), only use compressionParameters as argument API : added : prototypes ZSTD_*_usingCDict_advanced(), for direct control over frameParameters. API : improved: ZSTDMT_compressCCtx() reduced memory usage API : fix : ZSTDMT_compressCCtx() now provides srcSize in header (#634) API : fix : src size stored in frame header is controlled at end of frame API : fix : enforced consistent rules for pledgedSrcSize==0 (#641) API : fix : error code "GENERIC" replaced by "dstSizeTooSmall" when appropriate build: improved cmake script, by @Majlen build: enabled Multi-threading support for *BSD, by Baptiste Daroussin tools: updated Paramgrill. Command -O# provides best parameters for sample and speed target. new : contrib/linux-kernel version, by Nick Terrell v1.1.4 cli : new : can compress in *.gz format, using --format=gzip command, by Przemyslaw Skibinski cli : new : advanced benchmark command --priority=rt cli : fix : write on sparse-enabled file systems in 32-bits mode, by @ds77 cli : fix : --rm remains silent when input is stdin cli : experimental : xzstd, with support for xz/lzma decoding, by Przemyslaw Skibinski speed : improved decompression speed in streaming mode for single shot scenarios (+5%) memory: DDict (decompression dictionary) memory usage down from 150 KB to 20 KB arch: 32-bits variant able to generate and decode very long matches (>32 MB), by Sean Purcell API : new : ZSTD_findFrameCompressedSize(), ZSTD_getFrameContentSize(), ZSTD_findDecompressedSize() API : changed : dropped support of legacy versions <= v0.3 (can be changed by modifying ZSTD_LEGACY_SUPPORT value) build : new: meson build system in contrib/meson, by Dima Krasner build : improved cmake script, by @Majlen build : added -Wformat-security flag, as recommended by Padraig Brady doc : new : educational decoder, by Sean Purcell v1.1.3 cli : zstd can decompress .gz files (can be disabled with `make zstd-nogz` or `make HAVE_ZLIB=0`) cli : new : experimental target `make zstdmt`, with multi-threading support cli : new : improved dictionary builder "cover" (experimental), by Nick Terrell, based on prior work by Giuseppe Ottaviano. cli : new : advanced commands for detailed parameters, by Przemyslaw Skibinski cli : fix zstdless on Mac OS-X, by Andrew Janke cli : fix #232 "compress non-files" dictBuilder : improved dictionary generation quality, thanks to Nick Terrell API : new : lib/compress/ZSTDMT_compress.h multithreading API (experimental) API : new : ZSTD_create?Dict_byReference(), requested by Bartosz Taudul API : new : ZDICT_finalizeDictionary() API : fix : ZSTD_initCStream_usingCDict() properly writes dictID into frame header, by Gregory Szorc (#511) API : fix : all symbols properly exposed in libzstd, by Nick Terrell build : support for Solaris target, by Przemyslaw Skibinski doc : clarified specification, by Sean Purcell v1.1.2 API : streaming : decompression : changed : automatic implicit reset when chain-decoding new frames without init API : experimental : added : dictID retrieval functions, and ZSTD_initCStream_srcSize() API : zbuff : changed : prototypes now generate deprecation warnings lib : improved : faster decompression speed at ultra compression settings and 32-bits mode lib : changed : only public ZSTD_ symbols are now exposed lib : changed : reduced usage of stack memory lib : fixed : several corner case bugs, by Nick Terrell cli : new : gzstd, experimental version able to decode .gz files, by Przemyslaw Skibinski cli : new : preserve file attributes cli : new : added zstdless and zstdgrep tools cli : fixed : status displays total amount decoded, even for file consisting of multiple frames (like pzstd) cli : fixed : zstdcat zlib_wrapper : added support for gz* functions, by Przemyslaw Skibinski install : better compatibility with FreeBSD, by Dimitry Andric source tree : changed : zbuff source files moved to lib/deprecated v1.1.1 New : command -M#, --memory=, --memlimit=, --memlimit-decompress= to limit allowed memory consumption New : doc/zstd_manual.html, by Przemyslaw Skibinski Improved : slightly better compression ratio at --ultra levels (>= 20) Improved : better memory usage when using streaming compression API, thanks to @Rogier-5 report Added : API : ZSTD_initCStream_usingCDict(), ZSTD_initDStream_usingDDict() (experimental section) Added : example/multiple_streaming_compression.c Changed : zstd_errors.h is now installed within /include (and replaces errors_public.h) Updated man page Fixed : zstd-small, zstd-compress and zstd-decompress compilation targets v1.1.0 New : contrib/pzstd, parallel version of zstd, by Nick Terrell added : NetBSD install target (#338) Improved : speed for batches of small files Improved : speed of zlib wrapper, by Przemyslaw Skibinski Changed : libzstd on Windows supports legacy formats, by Christophe Chevalier Fixed : CLI -d output to stdout by default when input is stdin (#322) Fixed : CLI correctly detects console on Mac OS-X Fixed : CLI supports recursive mode `-r` on Mac OS-X Fixed : Legacy decoders use unified error codes, reported by benrg (#341), fixed by Przemyslaw Skibinski Fixed : compatibility with OpenBSD, reported by Juan Francisco Cantero Hurtado (#319) Fixed : compatibility with Hurd, by Przemyslaw Skibinski (#365) Fixed : zstd-pgo, reported by octoploid (#329) v1.0.0 Change Licensing, all project is now BSD, Copyright Facebook Small decompression speed improvement API : Streaming API supports legacy format API : ZDICT_getDictID(), ZSTD_sizeof_{CCtx, DCtx, CStream, DStream}(), ZSTD_setDStreamParameter() CLI supports legacy formats v0.4+ Fixed : compression fails on certain huge files, reported by Jesse McGrew Enhanced documentation, by Przemyslaw Skibinski v0.8.1 New streaming API Changed : --ultra now enables levels beyond 19 Changed : -i# now selects benchmark time in second Fixed : ZSTD_compress* can now compress > 4 GB in a single pass, reported by Nick Terrell Fixed : speed regression on specific patterns (#272) Fixed : support for Z_SYNC_FLUSH, by Dmitry Krot (#291) Fixed : ICC compilation, by Przemyslaw Skibinski v0.8.0 Improved : better speed on clang and gcc -O2, thanks to Eric Biggers New : Build on FreeBSD and DragonFly, thanks to JrMarino Changed : modified API : ZSTD_compressEnd() Fixed : legacy mode with ZSTD_HEAPMODE=0, by Christopher Bergqvist Fixed : premature end of frame when zero-sized raw block, reported by Eric Biggers Fixed : large dictionaries (> 384 KB), reported by Ilona Papava Fixed : checksum correctly checked in single-pass mode Fixed : combined --test amd --rm, reported by Andreas M. Nilsson Modified : minor compression level adaptations Updated : compression format specification to v0.2.0 changed : zstd.h moved to /lib directory v0.7.5 Transition version, supporting decoding of v0.8.x v0.7.4 Added : homebrew for Mac, by Daniel Cade Added : more examples Fixed : segfault when using small dictionaries, reported by Felix Handte Modified : default compression level for CLI is now 3 Updated : specification, to v0.1.1 v0.7.3 New : compression format specification New : `--` separator, stating that all following arguments are file names. Suggested by Chip Turner. New : `ZSTD_getDecompressedSize()` New : OpenBSD target, by Juan Francisco Cantero Hurtado New : `examples` directory fixed : dictBuilder using HC levels, reported by Bartosz Taudul fixed : legacy support from ZSTD_decompress_usingDDict(), reported by Felix Handte fixed : multi-blocks decoding with intermediate uncompressed blocks, reported by Greg Slazinski modified : removed "mem.h" and "error_public.h" dependencies from "zstd.h" (experimental section) modified : legacy functions no longer need magic number v0.7.2 fixed : ZSTD_decompressBlock() using multiple consecutive blocks. Reported by Greg Slazinski. fixed : potential segfault on very large files (many gigabytes). Reported by Chip Turner. fixed : CLI displays system error message when destination file cannot be created (#231). Reported by Chip Turner. v0.7.1 fixed : ZBUFF_compressEnd() called multiple times with too small `dst` buffer, reported by Christophe Chevalier fixed : dictBuilder fails if first sample is too small, reported by Руслан Ковалёв fixed : corruption issue, reported by cj modified : checksum enabled by default in command line mode v0.7.0 New : Support for directory compression, using `-r`, thanks to Przemyslaw Skibinski New : Command `--rm`, to remove source file after successful de/compression New : Visual build scripts, by Christophe Chevalier New : Support for Sparse File-systems (do not use space for zero-filled sectors) New : Frame checksum support New : Support pass-through mode (when using `-df`) API : more efficient Dictionary API : `ZSTD_compress_usingCDict()`, `ZSTD_decompress_usingDDict()` API : create dictionary files from custom content, by Giuseppe Ottaviano API : support for custom malloc/free functions New : controllable Dictionary ID New : Support for skippable frames v0.6.1 New : zlib wrapper API, thanks to Przemyslaw Skibinski New : Ability to compile compressor / decompressor separately Changed : new lib directory structure Fixed : Legacy codec v0.5 compatible with dictionary decompression Fixed : Decoder corruption error (#173) Fixed : null-string roundtrip (#176) New : benchmark mode can select directory as input Experimental : midipix support, VMS support v0.6.0 Stronger high compression modes, thanks to Przemyslaw Skibinski API : ZSTD_getFrameParams() provides size of decompressed content New : highest compression modes require `--ultra` command to fully unleash their capacity Fixed : zstd cli return error code > 0 and removes dst file artifact when decompression fails, thanks to Chip Turner v0.5.1 New : Optimal parsing => Very high compression modes, thanks to Przemyslaw Skibinski Changed : Dictionary builder integrated into libzstd and zstd cli Changed (!) : zstd cli now uses "multiple input files" as default mode. See `zstd -h`. Fix : high compression modes for big-endian platforms New : zstd cli : `-t` | `--test` command v0.5.0 New : dictionary builder utility Changed : streaming & dictionary API Improved : better compression of small data v0.4.7 Improved : small compression speed improvement in HC mode Changed : `zstd_decompress.c` has ZSTD_LEGACY_SUPPORT to 0 by default fix : bt search bug v0.4.6 fix : fast compression mode on Windows New : cmake configuration file, thanks to Artyom Dymchenko Improved : high compression mode on repetitive data New : block-level API New : ZSTD_duplicateCCtx() v0.4.5 new : -m/--multiple : compress/decompress multiple files v0.4.4 Fixed : high compression modes for Windows 32 bits new : external dictionary API extended to buffered mode and accessible through command line new : windows DLL project, thanks to Christophe Chevalier v0.4.3 : new : external dictionary API new : zstd-frugal v0.4.2 : Generic minor improvements for small blocks Fixed : big-endian compatibility, by Peter Harris (#85) v0.4.1 Fixed : ZSTD_LEGACY_SUPPORT=0 build mode (reported by Luben) removed `zstd.c` v0.4.0 Command line utility compatible with high compression levels Removed zstdhc => merged into zstd Added : ZBUFF API (see zstd_buffered.h) Rolling buffer support v0.3.6 small blocks params v0.3.5 minor generic compression improvements v0.3.4 Faster fast cLevels v0.3.3 Small compression ratio improvement v0.3.2 Fixed Visual Studio v0.3.1 : Small compression ratio improvement v0.3 HC mode : compression levels 2-26 v0.2.2 Fix : Visual Studio 2013 & 2015 release compilation, by Christophe Chevalier v0.2.1 Fix : Read errors, advanced fuzzer tests, by Hanno Böck v0.2.0 **Breaking format change** Faster decompression speed Can still decode v0.1 format v0.1.3 fix uninitialization warning, reported by Evan Nemerson v0.1.2 frame concatenation support v0.1.1 fix compression bug detects write-flush errors v0.1.0 first release Index: head/sys/contrib/zstd/Makefile =================================================================== --- head/sys/contrib/zstd/Makefile (revision 354776) +++ head/sys/contrib/zstd/Makefile (revision 354777) @@ -1,392 +1,392 @@ # ################################################################ # Copyright (c) 2015-present, Yann Collet, Facebook, Inc. # All rights reserved. # # This source code is licensed under both the BSD-style license (found in the # LICENSE file in the root directory of this source tree) and the GPLv2 (found # in the COPYING file in the root directory of this source tree). # ################################################################ PRGDIR = programs ZSTDDIR = lib BUILDIR = build ZWRAPDIR = zlibWrapper TESTDIR = tests FUZZDIR = $(TESTDIR)/fuzz # Define nul output VOID = /dev/null ifneq (,$(filter Windows%,$(OS))) EXT =.exe else EXT = endif ## default: Build lib-release and zstd-release .PHONY: default default: lib-release zstd-release .PHONY: all all: allmost examples manual contrib .PHONY: allmost allmost: allzstd zlibwrapper # skip zwrapper, can't build that on alternate architectures without the proper zlib installed .PHONY: allzstd allzstd: lib $(MAKE) -C $(PRGDIR) all $(MAKE) -C $(TESTDIR) all .PHONY: all32 all32: $(MAKE) -C $(PRGDIR) zstd32 $(MAKE) -C $(TESTDIR) all32 .PHONY: lib lib-release libzstd.a lib lib-release : @$(MAKE) -C $(ZSTDDIR) $@ .PHONY: zstd zstd-release zstd zstd-release: @$(MAKE) -C $(PRGDIR) $@ cp $(PRGDIR)/zstd$(EXT) . .PHONY: zstdmt zstdmt: @$(MAKE) -C $(PRGDIR) $@ cp $(PRGDIR)/zstd$(EXT) ./zstdmt$(EXT) .PHONY: zlibwrapper zlibwrapper: lib $(MAKE) -C $(ZWRAPDIR) all ## test: run long-duration tests .PHONY: test DEBUGLEVEL ?= 1 test: MOREFLAGS += -g -DDEBUGLEVEL=$(DEBUGLEVEL) -Werror test: MOREFLAGS="$(MOREFLAGS)" $(MAKE) -j -C $(PRGDIR) allVariants $(MAKE) -C $(TESTDIR) $@ + ZSTD=../../programs/zstd $(MAKE) -C doc/educational_decoder test ## shortest: same as `make check` .PHONY: shortest shortest: $(MAKE) -C $(TESTDIR) $@ ## check: run basic tests for `zstd` cli .PHONY: check check: shortest ## examples: build all examples in `/examples` directory .PHONY: examples examples: lib CPPFLAGS=-I../lib LDFLAGS=-L../lib $(MAKE) -C examples/ all ## manual: generate API documentation in html format .PHONY: manual manual: $(MAKE) -C contrib/gen_html $@ ## man: generate man page .PHONY: man man: $(MAKE) -C programs $@ ## contrib: build all supported projects in `/contrib` directory .PHONY: contrib contrib: lib $(MAKE) -C contrib/pzstd all $(MAKE) -C contrib/seekable_format/examples all - $(MAKE) -C contrib/adaptive-compression all $(MAKE) -C contrib/largeNbDicts all + cd contrib/single_file_decoder/ ; ./build_test.sh .PHONY: cleanTabs cleanTabs: cd contrib; ./cleanTabs .PHONY: clean clean: @$(MAKE) -C $(ZSTDDIR) $@ > $(VOID) @$(MAKE) -C $(PRGDIR) $@ > $(VOID) @$(MAKE) -C $(TESTDIR) $@ > $(VOID) @$(MAKE) -C $(ZWRAPDIR) $@ > $(VOID) @$(MAKE) -C examples/ $@ > $(VOID) @$(MAKE) -C contrib/gen_html $@ > $(VOID) @$(MAKE) -C contrib/pzstd $@ > $(VOID) @$(MAKE) -C contrib/seekable_format/examples $@ > $(VOID) - @$(MAKE) -C contrib/adaptive-compression $@ > $(VOID) @$(MAKE) -C contrib/largeNbDicts $@ > $(VOID) @$(RM) zstd$(EXT) zstdmt$(EXT) tmp* @$(RM) -r lz4 @echo Cleaning completed #------------------------------------------------------------------------------ # make install is validated only for Linux, macOS, Hurd and some BSD targets #------------------------------------------------------------------------------ ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU OpenBSD FreeBSD DragonFly NetBSD MSYS_NT Haiku)) HOST_OS = POSIX CMAKE_PARAMS = -DZSTD_BUILD_CONTRIB:BOOL=ON -DZSTD_BUILD_STATIC:BOOL=ON -DZSTD_BUILD_TESTS:BOOL=ON -DZSTD_ZLIB_SUPPORT:BOOL=ON -DZSTD_LZMA_SUPPORT:BOOL=ON -DCMAKE_BUILD_TYPE=Release HAVE_COLORNEVER = $(shell echo a | egrep --color=never a > /dev/null 2> /dev/null && echo 1 || echo 0) EGREP_OPTIONS ?= ifeq ($HAVE_COLORNEVER, 1) EGREP_OPTIONS += --color=never endif EGREP = egrep $(EGREP_OPTIONS) # Print a two column output of targets and their description. To add a target description, put a # comment in the Makefile with the format "## : ". For example: # ## list: Print all targets and their descriptions (if provided) .PHONY: list list: @TARGETS=$$($(MAKE) -pRrq -f $(lastword $(MAKEFILE_LIST)) : 2>/dev/null \ | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' \ | $(EGREP) -v -e '^[^[:alnum:]]' | sort); \ { \ printf "Target Name\tDescription\n"; \ printf "%0.s-" {1..16}; printf "\t"; printf "%0.s-" {1..40}; printf "\n"; \ for target in $$TARGETS; do \ line=$$($(EGREP) "^##[[:space:]]+$$target:" $(lastword $(MAKEFILE_LIST))); \ description=$$(echo $$line | awk '{i=index($$0,":"); print substr($$0,i+1)}' | xargs); \ printf "$$target\t$$description\n"; \ done \ } | column -t -s $$'\t' .PHONY: install armtest usan asan uasan install: @$(MAKE) -C $(ZSTDDIR) $@ @$(MAKE) -C $(PRGDIR) $@ .PHONY: uninstall uninstall: @$(MAKE) -C $(ZSTDDIR) $@ @$(MAKE) -C $(PRGDIR) $@ .PHONY: travis-install travis-install: $(MAKE) install PREFIX=~/install_test_dir .PHONY: gcc5build gcc5build: clean gcc-5 -v CC=gcc-5 $(MAKE) all MOREFLAGS="-Werror" .PHONY: gcc6build gcc6build: clean gcc-6 -v CC=gcc-6 $(MAKE) all MOREFLAGS="-Werror" .PHONY: gcc7build gcc7build: clean gcc-7 -v CC=gcc-7 $(MAKE) all MOREFLAGS="-Werror" .PHONY: clangbuild clangbuild: clean clang -v CXX=clang++ CC=clang CFLAGS="-Werror -Wconversion -Wno-sign-conversion -Wdocumentation" $(MAKE) all m32build: clean gcc -v $(MAKE) all32 armbuild: clean CC=arm-linux-gnueabi-gcc CFLAGS="-Werror" $(MAKE) allzstd aarch64build: clean CC=aarch64-linux-gnu-gcc CFLAGS="-Werror" $(MAKE) allzstd ppcbuild: clean CC=powerpc-linux-gnu-gcc CFLAGS="-m32 -Wno-attributes -Werror" $(MAKE) allzstd ppc64build: clean CC=powerpc-linux-gnu-gcc CFLAGS="-m64 -Werror" $(MAKE) allzstd armfuzz: clean CC=arm-linux-gnueabi-gcc QEMU_SYS=qemu-arm-static MOREFLAGS="-static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest aarch64fuzz: clean ld -v CC=aarch64-linux-gnu-gcc QEMU_SYS=qemu-aarch64-static MOREFLAGS="-static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest ppcfuzz: clean CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc-static MOREFLAGS="-static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest ppc64fuzz: clean CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static MOREFLAGS="-m64 -static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest .PHONY: cxxtest cxxtest: CXXFLAGS += -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror cxxtest: clean $(MAKE) -C $(PRGDIR) all CC="$(CXX) -Wno-deprecated" CFLAGS="$(CXXFLAGS)" # adding -Wno-deprecated to avoid clang++ warning on dealing with C files directly gcc5test: clean gcc-5 -v $(MAKE) all CC=gcc-5 MOREFLAGS="-Werror" gcc6test: clean gcc-6 -v $(MAKE) all CC=gcc-6 MOREFLAGS="-Werror" armtest: clean $(MAKE) -C $(TESTDIR) datagen # use native, faster $(MAKE) -C $(TESTDIR) test CC=arm-linux-gnueabi-gcc QEMU_SYS=qemu-arm-static ZSTDRTTEST= MOREFLAGS="-Werror -static" FUZZER_FLAGS=--no-big-tests aarch64test: $(MAKE) -C $(TESTDIR) datagen # use native, faster $(MAKE) -C $(TESTDIR) test CC=aarch64-linux-gnu-gcc QEMU_SYS=qemu-aarch64-static ZSTDRTTEST= MOREFLAGS="-Werror -static" FUZZER_FLAGS=--no-big-tests ppctest: clean $(MAKE) -C $(TESTDIR) datagen # use native, faster $(MAKE) -C $(TESTDIR) test CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc-static ZSTDRTTEST= MOREFLAGS="-Werror -Wno-attributes -static" FUZZER_FLAGS=--no-big-tests ppc64test: clean $(MAKE) -C $(TESTDIR) datagen # use native, faster $(MAKE) -C $(TESTDIR) test CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static ZSTDRTTEST= MOREFLAGS="-m64 -static" FUZZER_FLAGS=--no-big-tests arm-ppc-compilation: $(MAKE) -C $(PRGDIR) clean zstd CC=arm-linux-gnueabi-gcc QEMU_SYS=qemu-arm-static ZSTDRTTEST= MOREFLAGS="-Werror -static" $(MAKE) -C $(PRGDIR) clean zstd CC=aarch64-linux-gnu-gcc QEMU_SYS=qemu-aarch64-static ZSTDRTTEST= MOREFLAGS="-Werror -static" $(MAKE) -C $(PRGDIR) clean zstd CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc-static ZSTDRTTEST= MOREFLAGS="-Werror -Wno-attributes -static" $(MAKE) -C $(PRGDIR) clean zstd CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static ZSTDRTTEST= MOREFLAGS="-m64 -static" regressiontest: $(MAKE) -C $(FUZZDIR) regressiontest uasanregressiontest: $(MAKE) -C $(FUZZDIR) regressiontest CC=clang CXX=clang++ CFLAGS="-O3 -fsanitize=address,undefined" CXXFLAGS="-O3 -fsanitize=address,undefined" msanregressiontest: $(MAKE) -C $(FUZZDIR) regressiontest CC=clang CXX=clang++ CFLAGS="-O3 -fsanitize=memory" CXXFLAGS="-O3 -fsanitize=memory" # run UBsan with -fsanitize-recover=signed-integer-overflow # due to a bug in UBsan when doing pointer subtraction # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63303 usan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize-recover=signed-integer-overflow -fsanitize=undefined -Werror" asan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fsanitize=address -Werror" asan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize=address -Werror" $(MAKE) -C $(TESTDIR) $* msan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fsanitize=memory -fno-omit-frame-pointer -Werror" HAVE_LZMA=0 # datagen.c fails this test for no obvious reason msan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize=memory -fno-omit-frame-pointer -Werror" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) HAVE_LZMA=0 $* asan32: clean $(MAKE) -C $(TESTDIR) test32 CC=clang MOREFLAGS="-g -fsanitize=address" uasan: clean $(MAKE) test CC=clang MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize-recover=signed-integer-overflow -fsanitize=address,undefined -Werror" uasan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize-recover=signed-integer-overflow -fsanitize=address,undefined -Werror" $(MAKE) -C $(TESTDIR) $* tsan-%: clean LDFLAGS=-fuse-ld=gold MOREFLAGS="-g -fno-sanitize-recover=all -fsanitize=thread -Werror" $(MAKE) -C $(TESTDIR) $* FUZZER_FLAGS=--no-big-tests apt-install: sudo apt-get -yq --no-install-suggests --no-install-recommends --force-yes install $(APT_PACKAGES) apt-add-repo: sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test sudo apt-get update -y -qq ppcinstall: APT_PACKAGES="qemu-system-ppc qemu-user-static gcc-powerpc-linux-gnu" $(MAKE) apt-install arminstall: APT_PACKAGES="qemu-system-arm qemu-user-static gcc-arm-linux-gnueabi libc6-dev-armel-cross gcc-aarch64-linux-gnu libc6-dev-arm64-cross" $(MAKE) apt-install valgrindinstall: APT_PACKAGES="valgrind" $(MAKE) apt-install libc6install: APT_PACKAGES="libc6-dev-i386 gcc-multilib" $(MAKE) apt-install gcc6install: apt-add-repo APT_PACKAGES="libc6-dev-i386 gcc-multilib gcc-6 gcc-6-multilib" $(MAKE) apt-install gcc7install: apt-add-repo APT_PACKAGES="libc6-dev-i386 gcc-multilib gcc-7 gcc-7-multilib" $(MAKE) apt-install gcc8install: apt-add-repo APT_PACKAGES="libc6-dev-i386 gcc-multilib gcc-8 gcc-8-multilib" $(MAKE) apt-install gpp6install: apt-add-repo APT_PACKAGES="libc6-dev-i386 g++-multilib gcc-6 g++-6 g++-6-multilib" $(MAKE) apt-install clang38install: APT_PACKAGES="clang-3.8" $(MAKE) apt-install # Ubuntu 14.04 ships a too-old lz4 lz4install: [ -e lz4 ] || git clone https://github.com/lz4/lz4 && sudo $(MAKE) -C lz4 install endif ifneq (,$(filter MSYS%,$(shell uname))) HOST_OS = MSYS CMAKE_PARAMS = -G"MSYS Makefiles" -DZSTD_MULTITHREAD_SUPPORT:BOOL=OFF -DZSTD_BUILD_STATIC:BOOL=ON -DZSTD_BUILD_TESTS:BOOL=ON endif #------------------------------------------------------------------------ # target specific tests #------------------------------------------------------------------------ ifneq (,$(filter $(HOST_OS),MSYS POSIX)) cmakebuild: cmake --version $(RM) -r $(BUILDIR)/cmake/build mkdir $(BUILDIR)/cmake/build cd $(BUILDIR)/cmake/build ; cmake -DCMAKE_INSTALL_PREFIX:PATH=~/install_test_dir $(CMAKE_PARAMS) .. ; $(MAKE) install ; $(MAKE) uninstall c90build: clean $(CC) -v CFLAGS="-std=c90 -Werror" $(MAKE) allmost # will fail, due to missing support for `long long` gnu90build: clean $(CC) -v CFLAGS="-std=gnu90 -Werror" $(MAKE) allmost c99build: clean $(CC) -v CFLAGS="-std=c99 -Werror" $(MAKE) allmost gnu99build: clean $(CC) -v CFLAGS="-std=gnu99 -Werror" $(MAKE) allmost c11build: clean $(CC) -v CFLAGS="-std=c11 -Werror" $(MAKE) allmost bmix64build: clean $(CC) -v CFLAGS="-O3 -mbmi -Werror" $(MAKE) -C $(TESTDIR) test bmix32build: clean $(CC) -v CFLAGS="-O3 -mbmi -mx32 -Werror" $(MAKE) -C $(TESTDIR) test bmi32build: clean $(CC) -v CFLAGS="-O3 -mbmi -m32 -Werror" $(MAKE) -C $(TESTDIR) test # static analyzer test uses clang's scan-build # does not analyze zlibWrapper, due to detected issues in zlib source code staticAnalyze: SCANBUILD ?= scan-build staticAnalyze: $(CC) -v CC=$(CC) CPPFLAGS=-g $(SCANBUILD) --status-bugs -v $(MAKE) allzstd examples contrib endif Index: head/sys/contrib/zstd/README.md =================================================================== --- head/sys/contrib/zstd/README.md (revision 354776) +++ head/sys/contrib/zstd/README.md (revision 354777) @@ -1,170 +1,173 @@

Zstandard

__Zstandard__, or `zstd` as short version, is a fast lossless compression algorithm, targeting real-time compression scenarios at zlib-level and better compression ratios. It's backed by a very fast entropy stage, provided by [Huff0 and FSE library](https://github.com/Cyan4973/FiniteStateEntropy). The project is provided as an open-source dual [BSD](LICENSE) and [GPLv2](COPYING) licensed **C** library, and a command line utility producing and decoding `.zst`, `.gz`, `.xz` and `.lz4` files. Should your project require another programming language, a list of known ports and bindings is provided on [Zstandard homepage](http://www.zstd.net/#other-languages). **Development branch status:** [![Build Status][travisDevBadge]][travisLink] [![Build status][AppveyorDevBadge]][AppveyorLink] [![Build status][CircleDevBadge]][CircleLink] [![Build status][CirrusDevBadge]][CirrusLink] +[![Fuzzing Status][OSSFuzzBadge]][OSSFuzzLink] [travisDevBadge]: https://travis-ci.org/facebook/zstd.svg?branch=dev "Continuous Integration test suite" [travisLink]: https://travis-ci.org/facebook/zstd [AppveyorDevBadge]: https://ci.appveyor.com/api/projects/status/xt38wbdxjk5mrbem/branch/dev?svg=true "Windows test suite" [AppveyorLink]: https://ci.appveyor.com/project/YannCollet/zstd-p0yf0 [CircleDevBadge]: https://circleci.com/gh/facebook/zstd/tree/dev.svg?style=shield "Short test suite" [CircleLink]: https://circleci.com/gh/facebook/zstd [CirrusDevBadge]: https://api.cirrus-ci.com/github/facebook/zstd.svg?branch=dev [CirrusLink]: https://cirrus-ci.com/github/facebook/zstd +[OSSFuzzBadge]: https://oss-fuzz-build-logs.storage.googleapis.com/badges/zstd.svg +[OSSFuzzLink]: https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:zstd ## Benchmarks For reference, several fast compression algorithms were tested and compared on a server running Arch Linux (`Linux version 5.0.5-arch1-1`), with a Core i9-9900K CPU @ 5.0GHz, using [lzbench], an open-source in-memory benchmark by @inikep compiled with [gcc] 8.2.1, on the [Silesia compression corpus]. [lzbench]: https://github.com/inikep/lzbench [Silesia compression corpus]: http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia [gcc]: https://gcc.gnu.org/ | Compressor name | Ratio | Compression| Decompress.| | --------------- | ------| -----------| ---------- | | **zstd 1.4.0 -1** | 2.884 | 530 MB/s | 1360 MB/s | | zlib 1.2.11 -1 | 2.743 | 110 MB/s | 440 MB/s | | brotli 1.0.7 -0 | 2.701 | 430 MB/s | 470 MB/s | | quicklz 1.5.0 -1 | 2.238 | 600 MB/s | 800 MB/s | | lzo1x 2.09 -1 | 2.106 | 680 MB/s | 950 MB/s | | lz4 1.8.3 | 2.101 | 800 MB/s | 4220 MB/s | | snappy 1.1.4 | 2.073 | 580 MB/s | 2020 MB/s | | lzf 3.6 -1 | 2.077 | 440 MB/s | 930 MB/s | [zlib]: http://www.zlib.net/ [LZ4]: http://www.lz4.org/ Zstd can also offer stronger compression ratios at the cost of compression speed. Speed vs Compression trade-off is configurable by small increments. Decompression speed is preserved and remains roughly the same at all settings, a property shared by most LZ compression algorithms, such as [zlib] or lzma. The following tests were run on a server running Linux Debian (`Linux version 4.14.0-3-amd64`) with a Core i7-6700K CPU @ 4.0GHz, using [lzbench], an open-source in-memory benchmark by @inikep compiled with [gcc] 7.3.0, on the [Silesia compression corpus]. Compression Speed vs Ratio | Decompression Speed ---------------------------|-------------------- ![Compression Speed vs Ratio](doc/images/CSpeed2.png "Compression Speed vs Ratio") | ![Decompression Speed](doc/images/DSpeed3.png "Decompression Speed") A few other algorithms can produce higher compression ratios at slower speeds, falling outside of the graph. For a larger picture including slow modes, [click on this link](doc/images/DCspeed5.png). ## The case for Small Data compression Previous charts provide results applicable to typical file and stream scenarios (several MB). Small data comes with different perspectives. The smaller the amount of data to compress, the more difficult it is to compress. This problem is common to all compression algorithms, and reason is, compression algorithms learn from past data how to compress future data. But at the beginning of a new data set, there is no "past" to build upon. To solve this situation, Zstd offers a __training mode__, which can be used to tune the algorithm for a selected type of data. Training Zstandard is achieved by providing it with a few samples (one file per sample). The result of this training is stored in a file called "dictionary", which must be loaded before compression and decompression. Using this dictionary, the compression ratio achievable on small data improves dramatically. The following example uses the `github-users` [sample set](https://github.com/facebook/zstd/releases/tag/v1.1.3), created from [github public API](https://developer.github.com/v3/users/#get-all-users). It consists of roughly 10K records weighing about 1KB each. Compression Ratio | Compression Speed | Decompression Speed ------------------|-------------------|-------------------- ![Compression Ratio](doc/images/dict-cr.png "Compression Ratio") | ![Compression Speed](doc/images/dict-cs.png "Compression Speed") | ![Decompression Speed](doc/images/dict-ds.png "Decompression Speed") These compression gains are achieved while simultaneously providing _faster_ compression and decompression speeds. Training works if there is some correlation in a family of small data samples. The more data-specific a dictionary is, the more efficient it is (there is no _universal dictionary_). Hence, deploying one dictionary per type of data will provide the greatest benefits. Dictionary gains are mostly effective in the first few KB. Then, the compression algorithm will gradually use previously decoded content to better compress the rest of the file. ### Dictionary compression How To: 1. Create the dictionary `zstd --train FullPathToTrainingSet/* -o dictionaryName` 2. Compress with dictionary `zstd -D dictionaryName FILE` 3. Decompress with dictionary `zstd -D dictionaryName --decompress FILE.zst` ## Build instructions ### Makefile If your system is compatible with standard `make` (or `gmake`), invoking `make` in root directory will generate `zstd` cli in root directory. Other available options include: - `make install` : create and install zstd cli, library and man pages - `make check` : create and run `zstd`, tests its behavior on local platform ### cmake A `cmake` project generator is provided within `build/cmake`. It can generate Makefiles or other build scripts to create `zstd` binary, and `libzstd` dynamic and static libraries. By default, `CMAKE_BUILD_TYPE` is set to `Release`. ### Meson A Meson project is provided within [`build/meson`](build/meson). Follow build instructions in that directory. You can also take a look at [`.travis.yml`](.travis.yml) file for an example about how Meson is used to build this project. Note that default build type is **release**. ### Visual Studio (Windows) Going into `build` directory, you will find additional possibilities: - Projects for Visual Studio 2005, 2008 and 2010. + VS2010 project is compatible with VS2012, VS2013, VS2015 and VS2017. - Automated build scripts for Visual compiler by [@KrzysFR](https://github.com/KrzysFR), in `build/VS_scripts`, which will build `zstd` cli and `libzstd` library without any need to open Visual Studio solution. ### Buck You can build the zstd binary via buck by executing: `buck build programs:zstd` from the root of the repo. The output binary will be in `buck-out/gen/programs/`. ## Status Zstandard is currently deployed within Facebook. It is used continuously to compress large amounts of data in multiple formats and use cases. Zstandard is considered safe for production environments. ## License Zstandard is dual-licensed under [BSD](LICENSE) and [GPLv2](COPYING). ## Contributing The "dev" branch is the one where all contributions are merged before reaching "master". If you plan to propose a patch, please commit into the "dev" branch, or its own feature branch. Direct commit to "master" are not permitted. For more information, please read [CONTRIBUTING](CONTRIBUTING.md). Index: head/sys/contrib/zstd/appveyor.yml =================================================================== --- head/sys/contrib/zstd/appveyor.yml (revision 354776) +++ head/sys/contrib/zstd/appveyor.yml (revision 354777) @@ -1,251 +1,266 @@ +# Following tests are run _only_ on master branch +# To reproduce these tests, it's possible to push into a branch `appveyorTest` +# or a branch `visual*`, they will intentionnally trigger `master` tests + - version: 1.0.{build} branches: only: - master - appveyorTest - /visual*/ environment: matrix: - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x64" SCRIPT: "make allzstd MOREFLAGS=-static && make -C tests test-symbols fullbench-lib" ARTIFACT: "true" BUILD: "true" - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x86" SCRIPT: "make allzstd MOREFLAGS=-static" ARTIFACT: "true" BUILD: "true" - COMPILER: "clang" HOST: "mingw" PLATFORM: "x64" SCRIPT: "MOREFLAGS='--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion' make allzstd" BUILD: "true" - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x64" SCRIPT: "" TEST: "cmake" - COMPILER: "visual" HOST: "visual" PLATFORM: "x64" CONFIGURATION: "Debug" - COMPILER: "visual" HOST: "visual" PLATFORM: "Win32" CONFIGURATION: "Debug" - COMPILER: "visual" HOST: "visual" PLATFORM: "x64" CONFIGURATION: "Release" - COMPILER: "visual" HOST: "visual" PLATFORM: "Win32" CONFIGURATION: "Release" install: - ECHO Installing %COMPILER% %PLATFORM% %CONFIGURATION% - SET PATH_ORIGINAL=%PATH% - if [%HOST%]==[mingw] ( SET "PATH_MINGW32=C:\mingw-w64\i686-6.3.0-posix-dwarf-rt_v5-rev1\mingw32\bin" && SET "PATH_MINGW64=C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin" && COPY C:\msys64\usr\bin\make.exe C:\mingw-w64\i686-6.3.0-posix-dwarf-rt_v5-rev1\mingw32\bin\make.exe && COPY C:\msys64\usr\bin\make.exe C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin\make.exe ) - IF [%HOST%]==[visual] IF [%PLATFORM%]==[x64] ( SET ADDITIONALPARAM=/p:LibraryPath="C:\Program Files\Microsoft SDKs\Windows\v7.1\lib\x64;c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\lib\amd64;C:\Program Files (x86)\Microsoft Visual Studio 10.0\;C:\Program Files (x86)\Microsoft Visual Studio 10.0\lib\amd64;" ) build_script: - if [%HOST%]==[mingw] ( ( if [%PLATFORM%]==[x64] ( SET "PATH=%PATH_MINGW64%;%PATH_ORIGINAL%" ) else if [%PLATFORM%]==[x86] ( SET "PATH=%PATH_MINGW32%;%PATH_ORIGINAL%" ) ) ) - if [%HOST%]==[mingw] if [%BUILD%]==[true] ( make -v && sh -c "%COMPILER% -v" && ECHO Building zlib to static link && SET "CC=%COMPILER%" && sh -c "cd .. && git clone --depth 1 --branch v1.2.11 https://github.com/madler/zlib" && sh -c "cd ../zlib && make -f win32/Makefile.gcc libz.a" ECHO Building zstd && SET "CPPFLAGS=-I../../zlib" && SET "LDFLAGS=../../zlib/libz.a" && sh -c "%SCRIPT%" && ( if [%COMPILER%]==[gcc] if [%ARTIFACT%]==[true] ECHO Creating artifacts && ECHO %cd% && lib\dll\example\build_package.bat && make -C programs DEBUGFLAGS= clean zstd && cd programs\ && 7z a -tzip -mx9 zstd-win-binary-%PLATFORM%.zip zstd.exe && appveyor PushArtifact zstd-win-binary-%PLATFORM%.zip && cp zstd.exe ..\bin\zstd.exe && git clone --depth 1 --branch master https://github.com/facebook/zstd && cd zstd && git archive --format=tar master -o zstd-src.tar && ..\zstd -19 zstd-src.tar && appveyor PushArtifact zstd-src.tar.zst && certUtil -hashfile zstd-src.tar.zst SHA256 > zstd-src.tar.zst.sha256.sig && appveyor PushArtifact zstd-src.tar.zst.sha256.sig && cd ..\..\bin\ && 7z a -tzip -mx9 zstd-win-release-%PLATFORM%.zip * && appveyor PushArtifact zstd-win-release-%PLATFORM%.zip ) ) - if [%HOST%]==[visual] ( ECHO *** && ECHO *** Building Visual Studio 2008 %PLATFORM%\%CONFIGURATION% in %APPVEYOR_BUILD_FOLDER% && ECHO *** && msbuild "build\VS2008\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v90 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2008\bin\%PLATFORM%\%CONFIGURATION%\*.exe && MD5sum build/VS2008/bin/%PLATFORM%/%CONFIGURATION%/*.exe && COPY build\VS2008\bin\%PLATFORM%\%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2008_%PLATFORM%_%CONFIGURATION%.exe && ECHO *** && ECHO *** Building Visual Studio 2010 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" %ADDITIONALPARAM% /m /verbosity:minimal /property:PlatformToolset=v100 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" %ADDITIONALPARAM% /m /verbosity:minimal /property:PlatformToolset=v100 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2010_%PLATFORM%_%CONFIGURATION%.exe && ECHO *** && ECHO *** Building Visual Studio 2012 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v110 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v110 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2012_%PLATFORM%_%CONFIGURATION%.exe && ECHO *** && ECHO *** Building Visual Studio 2013 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v120 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v120 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2013_%PLATFORM%_%CONFIGURATION%.exe && ECHO *** && ECHO *** Building Visual Studio 2015 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v140 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v140 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2015_%PLATFORM%_%CONFIGURATION%.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe tests\ ) test_script: - ECHO Testing %COMPILER% %PLATFORM% %CONFIGURATION% - SET "CC=gcc" - SET "CXX=g++" - if [%TEST%]==[cmake] ( mkdir build\cmake\build && cd build\cmake\build && cmake -G "Visual Studio 14 2015 Win64" .. && cd ..\..\.. && make clean ) - SET "FUZZERTEST=-T30s" - if [%HOST%]==[visual] if [%CONFIGURATION%]==[Release] ( CD tests && SET ZSTD=./zstd.exe && sh -e playTests.sh --test-large-data && fullbench.exe -i1 && fullbench.exe -i1 -P0 && - fuzzer_VS2008_%PLATFORM%_Release.exe %FUZZERTEST% && - fuzzer_VS2010_%PLATFORM%_Release.exe %FUZZERTEST% && fuzzer_VS2012_%PLATFORM%_Release.exe %FUZZERTEST% && fuzzer_VS2013_%PLATFORM%_Release.exe %FUZZERTEST% && fuzzer_VS2015_%PLATFORM%_Release.exe %FUZZERTEST% ) + +# The following tests are for regular pushes +# into `dev` or some feature branch +# There run less tests, for shorter feedback loop + - version: 1.0.{build} environment: matrix: - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x64" SCRIPT: "CPPFLAGS=-DDEBUGLEVEL=2 CFLAGS=-Werror make -j allzstd DEBUGLEVEL=2" - COMPILER: "gcc" HOST: "mingw" PLATFORM: "x86" SCRIPT: "CFLAGS=-Werror make -j allzstd" - COMPILER: "clang" HOST: "mingw" PLATFORM: "x64" SCRIPT: "CFLAGS='--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion' make -j allzstd" - COMPILER: "visual" HOST: "visual" PLATFORM: "x64" CONFIGURATION: "Debug" - COMPILER: "visual" HOST: "visual" PLATFORM: "Win32" CONFIGURATION: "Debug" - COMPILER: "visual" HOST: "visual" PLATFORM: "x64" CONFIGURATION: "Release" - COMPILER: "visual" HOST: "visual" PLATFORM: "Win32" CONFIGURATION: "Release" install: - ECHO Installing %COMPILER% %PLATFORM% %CONFIGURATION% - SET PATH_ORIGINAL=%PATH% - if [%HOST%]==[mingw] ( SET "PATH_MINGW32=C:\mingw-w64\i686-6.3.0-posix-dwarf-rt_v5-rev1\mingw32\bin" && SET "PATH_MINGW64=C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin" && COPY C:\msys64\usr\bin\make.exe C:\mingw-w64\i686-6.3.0-posix-dwarf-rt_v5-rev1\mingw32\bin\make.exe && COPY C:\msys64\usr\bin\make.exe C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin\make.exe ) - IF [%HOST%]==[visual] IF [%PLATFORM%]==[x64] ( SET ADDITIONALPARAM=/p:LibraryPath="C:\Program Files\Microsoft SDKs\Windows\v7.1\lib\x64;c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\lib\amd64;C:\Program Files (x86)\Microsoft Visual Studio 10.0\;C:\Program Files (x86)\Microsoft Visual Studio 10.0\lib\amd64;" ) build_script: - ECHO Building %COMPILER% %PLATFORM% %CONFIGURATION% - if [%HOST%]==[mingw] ( ( if [%PLATFORM%]==[x64] ( SET "PATH=%PATH_MINGW64%;%PATH_ORIGINAL%" ) else if [%PLATFORM%]==[x86] ( SET "PATH=%PATH_MINGW32%;%PATH_ORIGINAL%" ) ) && make -v && sh -c "%COMPILER% -v" && set "CC=%COMPILER%" && sh -c "%SCRIPT%" ) - if [%HOST%]==[visual] ( ECHO *** && ECHO *** Building Visual Studio 2015 %PLATFORM%\%CONFIGURATION% && ECHO *** && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v140 /p:ForceImportBeforeCppTargets=%APPVEYOR_BUILD_FOLDER%\build\VS2010\CompileAsCpp.props /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && msbuild "build\VS2010\zstd.sln" /m /verbosity:minimal /property:PlatformToolset=v140 /t:Clean,Build /p:Platform=%PLATFORM% /p:Configuration=%CONFIGURATION% /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" && DIR build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe && MD5sum build/VS2010/bin/%PLATFORM%_%CONFIGURATION%/*.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\fuzzer.exe tests\fuzzer_VS2015_%PLATFORM%_%CONFIGURATION%.exe && COPY build\VS2010\bin\%PLATFORM%_%CONFIGURATION%\*.exe tests\ + ) + + + test_script: + - ECHO Testing %COMPILER% %PLATFORM% %CONFIGURATION% + - if [%HOST%]==[mingw] ( + set "CC=%COMPILER%" && + make check ) Index: head/sys/contrib/zstd/contrib/gen_html/.gitignore =================================================================== --- head/sys/contrib/zstd/contrib/gen_html/.gitignore (revision 354776) +++ head/sys/contrib/zstd/contrib/gen_html/.gitignore (nonexistent) @@ -1,3 +0,0 @@ -# make artefact -gen_html -zstd_manual.html Index: head/sys/contrib/zstd/contrib/pzstd/.gitignore =================================================================== --- head/sys/contrib/zstd/contrib/pzstd/.gitignore (revision 354776) +++ head/sys/contrib/zstd/contrib/pzstd/.gitignore (nonexistent) @@ -1,2 +0,0 @@ -# compilation result -pzstd Index: head/sys/contrib/zstd/contrib/seekable_format/examples/.gitignore =================================================================== --- head/sys/contrib/zstd/contrib/seekable_format/examples/.gitignore (revision 354776) +++ head/sys/contrib/zstd/contrib/seekable_format/examples/.gitignore (nonexistent) @@ -1,5 +0,0 @@ -seekable_compression -seekable_decompression -seekable_decompression_mem -parallel_processing -parallel_compression Index: head/sys/contrib/zstd/doc/educational_decoder/Makefile =================================================================== --- head/sys/contrib/zstd/doc/educational_decoder/Makefile (revision 354776) +++ head/sys/contrib/zstd/doc/educational_decoder/Makefile (revision 354777) @@ -1,34 +1,62 @@ +# ################################################################ +# Copyright (c) 2016-present, Yann Collet, Facebook, Inc. +# All rights reserved. +# +# This source code is licensed under both the BSD-style license (found in the +# LICENSE file in the root directory of this source tree) and the GPLv2 (found +# in the COPYING file in the root directory of this source tree). +# ################################################################ + +ZSTD ?= zstd # note: requires zstd installation on local system + +UNAME?= $(shell uname) +ifeq ($(UNAME), SunOS) +DIFF ?= gdiff +else +DIFF ?= diff +endif + HARNESS_FILES=*.c MULTITHREAD_LDFLAGS = -pthread DEBUGFLAGS= -g -DZSTD_DEBUG=1 CPPFLAGS += -I$(ZSTDDIR) -I$(ZSTDDIR)/common -I$(ZSTDDIR)/compress \ -I$(ZSTDDIR)/dictBuilder -I$(ZSTDDIR)/deprecated -I$(PRGDIR) -CFLAGS ?= -O3 +CFLAGS ?= -O2 CFLAGS += -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \ - -Wstrict-aliasing=1 -Wswitch-enum -Wdeclaration-after-statement \ - -Wstrict-prototypes -Wundef \ + -Wstrict-aliasing=1 -Wswitch-enum \ + -Wredundant-decls -Wstrict-prototypes -Wundef \ -Wvla -Wformat=2 -Winit-self -Wfloat-equal -Wwrite-strings \ - -Wredundant-decls + -std=c99 CFLAGS += $(DEBUGFLAGS) CFLAGS += $(MOREFLAGS) FLAGS = $(CPPFLAGS) $(CFLAGS) $(LDFLAGS) $(MULTITHREAD_LDFLAGS) harness: $(HARNESS_FILES) $(CC) $(FLAGS) $^ -o $@ clean: - @$(RM) -f harness - @$(RM) -rf harness.dSYM + @$(RM) harness + @$(RM) -rf harness.dSYM # MacOS specific test: harness - @zstd README.md -o tmp.zst + # + # Testing single-file decompression with educational decoder + # + @$(ZSTD) -f README.md -o tmp.zst @./harness tmp.zst tmp - @diff -s tmp README.md - @$(RM) -f tmp* - @zstd --train harness.c zstd_decompress.c zstd_decompress.h README.md - @zstd -D dictionary README.md -o tmp.zst + @$(DIFF) -s tmp README.md + @$(RM) tmp* + # + # Testing dictionary decompression with education decoder + # + # note : files are presented multiple for training, to reach minimum threshold + @$(ZSTD) --train harness.c zstd_decompress.c zstd_decompress.h README.md \ + harness.c zstd_decompress.c zstd_decompress.h README.md \ + harness.c zstd_decompress.c zstd_decompress.h README.md \ + -o dictionary + @$(ZSTD) -f README.md -D dictionary -o tmp.zst @./harness tmp.zst tmp dictionary - @diff -s tmp README.md - @$(RM) -f tmp* dictionary - @make clean + @$(DIFF) -s tmp README.md + @$(RM) tmp* dictionary + @$(MAKE) clean Index: head/sys/contrib/zstd/doc/educational_decoder/harness.c =================================================================== --- head/sys/contrib/zstd/doc/educational_decoder/harness.c (revision 354776) +++ head/sys/contrib/zstd/doc/educational_decoder/harness.c (revision 354777) @@ -1,125 +1,128 @@ /* * Copyright (c) 2017-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). */ #include #include #include "zstd_decompress.h" typedef unsigned char u8; // If the data doesn't have decompressed size with it, fallback on assuming the // compression ratio is at most 16 #define MAX_COMPRESSION_RATIO (16) // Protect against allocating too much memory for output #define MAX_OUTPUT_SIZE ((size_t)1024 * 1024 * 1024) -u8 *input; -u8 *output; -u8 *dict; - -size_t read_file(const char *path, u8 **ptr) { - FILE *f = fopen(path, "rb"); +static size_t read_file(const char *path, u8 **ptr) +{ + FILE* const f = fopen(path, "rb"); if (!f) { - fprintf(stderr, "failed to open file %s\n", path); + fprintf(stderr, "failed to open file %s \n", path); exit(1); } fseek(f, 0L, SEEK_END); - size_t size = ftell(f); + size_t const size = (size_t)ftell(f); rewind(f); *ptr = malloc(size); if (!ptr) { - fprintf(stderr, "failed to allocate memory to hold %s\n", path); + fprintf(stderr, "failed to allocate memory to hold %s \n", path); exit(1); } - size_t pos = 0; - while (!feof(f)) { - size_t read = fread(&(*ptr)[pos], 1, size, f); - if (ferror(f)) { - fprintf(stderr, "error while reading file %s\n", path); - exit(1); - } - pos += read; + size_t const read = fread(*ptr, 1, size, f); + if (read != size) { /* must read everything in one pass */ + fprintf(stderr, "error while reading file %s \n", path); + exit(1); } fclose(f); - return pos; + return read; } -void write_file(const char *path, const u8 *ptr, size_t size) { - FILE *f = fopen(path, "wb"); +static void write_file(const char *path, const u8 *ptr, size_t size) +{ + FILE* const f = fopen(path, "wb"); + if (!f) { + fprintf(stderr, "failed to open file %s \n", path); + exit(1); + } size_t written = 0; while (written < size) { - written += fwrite(&ptr[written], 1, size, f); + written += fwrite(ptr+written, 1, size, f); if (ferror(f)) { fprintf(stderr, "error while writing file %s\n", path); exit(1); - } - } + } } fclose(f); } -int main(int argc, char **argv) { +int main(int argc, char **argv) +{ if (argc < 3) { - fprintf(stderr, "usage: %s [dictionary]\n", + fprintf(stderr, "usage: %s [dictionary] \n", argv[0]); return 1; } - size_t input_size = read_file(argv[1], &input); + u8* input; + size_t const input_size = read_file(argv[1], &input); + + u8* dict = NULL; size_t dict_size = 0; if (argc >= 4) { dict_size = read_file(argv[3], &dict); } - size_t decompressed_size = ZSTD_get_decompressed_size(input, input_size); - if (decompressed_size == (size_t)-1) { - decompressed_size = MAX_COMPRESSION_RATIO * input_size; + size_t out_capacity = ZSTD_get_decompressed_size(input, input_size); + if (out_capacity == (size_t)-1) { + out_capacity = MAX_COMPRESSION_RATIO * input_size; fprintf(stderr, "WARNING: Compressed data does not contain " "decompressed size, going to assume the compression " "ratio is at most %d (decompressed size of at most " - "%zu)\n", - MAX_COMPRESSION_RATIO, decompressed_size); + "%u) \n", + MAX_COMPRESSION_RATIO, (unsigned)out_capacity); } - if (decompressed_size > MAX_OUTPUT_SIZE) { + if (out_capacity > MAX_OUTPUT_SIZE) { fprintf(stderr, - "Required output size too large for this implementation\n"); + "Required output size too large for this implementation \n"); return 1; } - output = malloc(decompressed_size); + + u8* const output = malloc(out_capacity); if (!output) { - fprintf(stderr, "failed to allocate memory\n"); + fprintf(stderr, "failed to allocate memory \n"); return 1; } dictionary_t* const parsed_dict = create_dictionary(); if (dict) { parse_dictionary(parsed_dict, dict, dict_size); } - size_t decompressed = - ZSTD_decompress_with_dict(output, decompressed_size, - input, input_size, parsed_dict); + size_t const decompressed_size = + ZSTD_decompress_with_dict(output, out_capacity, + input, input_size, + parsed_dict); free_dictionary(parsed_dict); - write_file(argv[2], output, decompressed); + write_file(argv[2], output, decompressed_size); free(input); free(output); free(dict); - input = output = dict = NULL; + return 0; } Index: head/sys/contrib/zstd/doc/educational_decoder/zstd_decompress.c =================================================================== --- head/sys/contrib/zstd/doc/educational_decoder/zstd_decompress.c (revision 354776) +++ head/sys/contrib/zstd/doc/educational_decoder/zstd_decompress.c (revision 354777) @@ -1,2303 +1,2303 @@ /* * Copyright (c) 2017-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). */ /// Zstandard educational decoder implementation /// See https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md #include #include #include #include #include "zstd_decompress.h" /******* UTILITY MACROS AND TYPES *********************************************/ // Max block size decompressed size is 128 KB and literal blocks can't be // larger than their block #define MAX_LITERALS_SIZE ((size_t)128 * 1024) #define MAX(a, b) ((a) > (b) ? (a) : (b)) #define MIN(a, b) ((a) < (b) ? (a) : (b)) /// This decoder calls exit(1) when it encounters an error, however a production /// library should propagate error codes #define ERROR(s) \ do { \ fprintf(stderr, "Error: %s\n", s); \ exit(1); \ } while (0) #define INP_SIZE() \ ERROR("Input buffer smaller than it should be or input is " \ "corrupted") #define OUT_SIZE() ERROR("Output buffer too small for output") #define CORRUPTION() ERROR("Corruption detected while decompressing") #define BAD_ALLOC() ERROR("Memory allocation error") #define IMPOSSIBLE() ERROR("An impossibility has occurred") typedef uint8_t u8; typedef uint16_t u16; typedef uint32_t u32; typedef uint64_t u64; typedef int8_t i8; typedef int16_t i16; typedef int32_t i32; typedef int64_t i64; /******* END UTILITY MACROS AND TYPES *****************************************/ /******* IMPLEMENTATION PRIMITIVE PROTOTYPES **********************************/ /// The implementations for these functions can be found at the bottom of this /// file. They implement low-level functionality needed for the higher level /// decompression functions. /*** IO STREAM OPERATIONS *************/ /// ostream_t/istream_t are used to wrap the pointers/length data passed into /// ZSTD_decompress, so that all IO operations are safely bounds checked /// They are written/read forward, and reads are treated as little-endian /// They should be used opaquely to ensure safety typedef struct { u8 *ptr; size_t len; } ostream_t; typedef struct { const u8 *ptr; size_t len; // Input often reads a few bits at a time, so maintain an internal offset int bit_offset; } istream_t; /// The following two functions are the only ones that allow the istream to be /// non-byte aligned /// Reads `num` bits from a bitstream, and updates the internal offset static inline u64 IO_read_bits(istream_t *const in, const int num_bits); /// Backs-up the stream by `num` bits so they can be read again static inline void IO_rewind_bits(istream_t *const in, const int num_bits); /// If the remaining bits in a byte will be unused, advance to the end of the /// byte static inline void IO_align_stream(istream_t *const in); /// Write the given byte into the output stream static inline void IO_write_byte(ostream_t *const out, u8 symb); /// Returns the number of bytes left to be read in this stream. The stream must /// be byte aligned. static inline size_t IO_istream_len(const istream_t *const in); /// Advances the stream by `len` bytes, and returns a pointer to the chunk that /// was skipped. The stream must be byte aligned. static inline const u8 *IO_get_read_ptr(istream_t *const in, size_t len); /// Advances the stream by `len` bytes, and returns a pointer to the chunk that /// was skipped so it can be written to. static inline u8 *IO_get_write_ptr(ostream_t *const out, size_t len); /// Advance the inner state by `len` bytes. The stream must be byte aligned. static inline void IO_advance_input(istream_t *const in, size_t len); /// Returns an `ostream_t` constructed from the given pointer and length. static inline ostream_t IO_make_ostream(u8 *out, size_t len); /// Returns an `istream_t` constructed from the given pointer and length. static inline istream_t IO_make_istream(const u8 *in, size_t len); /// Returns an `istream_t` with the same base as `in`, and length `len`. /// Then, advance `in` to account for the consumed bytes. /// `in` must be byte aligned. static inline istream_t IO_make_sub_istream(istream_t *const in, size_t len); /*** END IO STREAM OPERATIONS *********/ /*** BITSTREAM OPERATIONS *************/ /// Read `num` bits (up to 64) from `src + offset`, where `offset` is in bits, /// and return them interpreted as a little-endian unsigned integer. static inline u64 read_bits_LE(const u8 *src, const int num_bits, const size_t offset); /// Read bits from the end of a HUF or FSE bitstream. `offset` is in bits, so /// it updates `offset` to `offset - bits`, and then reads `bits` bits from /// `src + offset`. If the offset becomes negative, the extra bits at the /// bottom are filled in with `0` bits instead of reading from before `src`. static inline u64 STREAM_read_bits(const u8 *src, const int bits, i64 *const offset); /*** END BITSTREAM OPERATIONS *********/ /*** BIT COUNTING OPERATIONS **********/ /// Returns the index of the highest set bit in `num`, or `-1` if `num == 0` static inline int highest_set_bit(const u64 num); /*** END BIT COUNTING OPERATIONS ******/ /*** HUFFMAN PRIMITIVES ***************/ // Table decode method uses exponential memory, so we need to limit depth #define HUF_MAX_BITS (16) // Limit the maximum number of symbols to 256 so we can store a symbol in a byte #define HUF_MAX_SYMBS (256) /// Structure containing all tables necessary for efficient Huffman decoding typedef struct { u8 *symbols; u8 *num_bits; int max_bits; } HUF_dtable; /// Decode a single symbol and read in enough bits to refresh the state static inline u8 HUF_decode_symbol(const HUF_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Read in a full state's worth of bits to initialize it static inline void HUF_init_state(const HUF_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Decompresses a single Huffman stream, returns the number of bytes decoded. /// `src_len` must be the exact length of the Huffman-coded block. static size_t HUF_decompress_1stream(const HUF_dtable *const dtable, ostream_t *const out, istream_t *const in); /// Same as previous but decodes 4 streams, formatted as in the Zstandard /// specification. /// `src_len` must be the exact length of the Huffman-coded block. static size_t HUF_decompress_4stream(const HUF_dtable *const dtable, ostream_t *const out, istream_t *const in); /// Initialize a Huffman decoding table using the table of bit counts provided static void HUF_init_dtable(HUF_dtable *const table, const u8 *const bits, const int num_symbs); /// Initialize a Huffman decoding table using the table of weights provided /// Weights follow the definition provided in the Zstandard specification static void HUF_init_dtable_usingweights(HUF_dtable *const table, const u8 *const weights, const int num_symbs); /// Free the malloc'ed parts of a decoding table static void HUF_free_dtable(HUF_dtable *const dtable); /// Deep copy a decoding table, so that it can be used and free'd without /// impacting the source table. static void HUF_copy_dtable(HUF_dtable *const dst, const HUF_dtable *const src); /*** END HUFFMAN PRIMITIVES ***********/ /*** FSE PRIMITIVES *******************/ /// For more description of FSE see /// https://github.com/Cyan4973/FiniteStateEntropy/ // FSE table decoding uses exponential memory, so limit the maximum accuracy #define FSE_MAX_ACCURACY_LOG (15) // Limit the maximum number of symbols so they can be stored in a single byte #define FSE_MAX_SYMBS (256) /// The tables needed to decode FSE encoded streams typedef struct { u8 *symbols; u8 *num_bits; u16 *new_state_base; int accuracy_log; } FSE_dtable; /// Return the symbol for the current state static inline u8 FSE_peek_symbol(const FSE_dtable *const dtable, const u16 state); /// Read the number of bits necessary to update state, update, and shift offset /// back to reflect the bits read static inline void FSE_update_state(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Combine peek and update: decode a symbol and update the state static inline u8 FSE_decode_symbol(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Read bits from the stream to initialize the state and shift offset back static inline void FSE_init_state(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset); /// Decompress two interleaved bitstreams (e.g. compressed Huffman weights) /// using an FSE decoding table. `src_len` must be the exact length of the /// block. static size_t FSE_decompress_interleaved2(const FSE_dtable *const dtable, ostream_t *const out, istream_t *const in); /// Initialize a decoding table using normalized frequencies. static void FSE_init_dtable(FSE_dtable *const dtable, const i16 *const norm_freqs, const int num_symbs, const int accuracy_log); /// Decode an FSE header as defined in the Zstandard format specification and /// use the decoded frequencies to initialize a decoding table. static void FSE_decode_header(FSE_dtable *const dtable, istream_t *const in, const int max_accuracy_log); /// Initialize an FSE table that will always return the same symbol and consume /// 0 bits per symbol, to be used for RLE mode in sequence commands static void FSE_init_dtable_rle(FSE_dtable *const dtable, const u8 symb); /// Free the malloc'ed parts of a decoding table static void FSE_free_dtable(FSE_dtable *const dtable); /// Deep copy a decoding table, so that it can be used and free'd without /// impacting the source table. static void FSE_copy_dtable(FSE_dtable *const dst, const FSE_dtable *const src); /*** END FSE PRIMITIVES ***************/ /******* END IMPLEMENTATION PRIMITIVE PROTOTYPES ******************************/ /******* ZSTD HELPER STRUCTS AND PROTOTYPES ***********************************/ /// A small structure that can be reused in various places that need to access /// frame header information typedef struct { // The size of window that we need to be able to contiguously store for // references size_t window_size; // The total output size of this compressed frame size_t frame_content_size; // The dictionary id if this frame uses one u32 dictionary_id; // Whether or not the content of this frame has a checksum int content_checksum_flag; // Whether or not the output for this frame is in a single segment int single_segment_flag; } frame_header_t; /// The context needed to decode blocks in a frame typedef struct { frame_header_t header; // The total amount of data available for backreferences, to determine if an // offset too large to be correct size_t current_total_output; const u8 *dict_content; size_t dict_content_len; // Entropy encoding tables so they can be repeated by future blocks instead // of retransmitting HUF_dtable literals_dtable; FSE_dtable ll_dtable; FSE_dtable ml_dtable; FSE_dtable of_dtable; // The last 3 offsets for the special "repeat offsets". u64 previous_offsets[3]; } frame_context_t; /// The decoded contents of a dictionary so that it doesn't have to be repeated /// for each frame that uses it struct dictionary_s { // Entropy tables HUF_dtable literals_dtable; FSE_dtable ll_dtable; FSE_dtable ml_dtable; FSE_dtable of_dtable; // Raw content for backreferences u8 *content; size_t content_size; // Offset history to prepopulate the frame's history u64 previous_offsets[3]; u32 dictionary_id; }; /// A tuple containing the parts necessary to decode and execute a ZSTD sequence /// command typedef struct { u32 literal_length; u32 match_length; u32 offset; } sequence_command_t; /// The decoder works top-down, starting at the high level like Zstd frames, and /// working down to lower more technical levels such as blocks, literals, and /// sequences. The high-level functions roughly follow the outline of the /// format specification: /// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md /// Before the implementation of each high-level function declared here, the /// prototypes for their helper functions are defined and explained /// Decode a single Zstd frame, or error if the input is not a valid frame. /// Accepts a dict argument, which may be NULL indicating no dictionary. /// See /// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#frame-concatenation static void decode_frame(ostream_t *const out, istream_t *const in, const dictionary_t *const dict); // Decode data in a compressed block static void decompress_block(frame_context_t *const ctx, ostream_t *const out, istream_t *const in); // Decode the literals section of a block static size_t decode_literals(frame_context_t *const ctx, istream_t *const in, u8 **const literals); // Decode the sequences part of a block static size_t decode_sequences(frame_context_t *const ctx, istream_t *const in, sequence_command_t **const sequences); // Execute the decoded sequences on the literals block static void execute_sequences(frame_context_t *const ctx, ostream_t *const out, const u8 *const literals, const size_t literals_len, const sequence_command_t *const sequences, const size_t num_sequences); // Copies literals and returns the total literal length that was copied static u32 copy_literals(const size_t seq, istream_t *litstream, ostream_t *const out); // Given an offset code from a sequence command (either an actual offset value // or an index for previous offset), computes the correct offset and updates // the offset history static size_t compute_offset(sequence_command_t seq, u64 *const offset_hist); // Given an offset, match length, and total output, as well as the frame // context for the dictionary, determines if the dictionary is used and // executes the copy operation static void execute_match_copy(frame_context_t *const ctx, size_t offset, size_t match_length, size_t total_output, ostream_t *const out); /******* END ZSTD HELPER STRUCTS AND PROTOTYPES *******************************/ size_t ZSTD_decompress(void *const dst, const size_t dst_len, const void *const src, const size_t src_len) { dictionary_t* uninit_dict = create_dictionary(); size_t const decomp_size = ZSTD_decompress_with_dict(dst, dst_len, src, src_len, uninit_dict); free_dictionary(uninit_dict); return decomp_size; } size_t ZSTD_decompress_with_dict(void *const dst, const size_t dst_len, const void *const src, const size_t src_len, dictionary_t* parsed_dict) { istream_t in = IO_make_istream(src, src_len); ostream_t out = IO_make_ostream(dst, dst_len); // "A content compressed by Zstandard is transformed into a Zstandard frame. // Multiple frames can be appended into a single file or stream. A frame is // totally independent, has a defined beginning and end, and a set of // parameters which tells the decoder how to decompress it." /* this decoder assumes decompression of a single frame */ decode_frame(&out, &in, parsed_dict); - return out.ptr - (u8 *)dst; + return (size_t)(out.ptr - (u8 *)dst); } /******* FRAME DECODING ******************************************************/ static void decode_data_frame(ostream_t *const out, istream_t *const in, const dictionary_t *const dict); static void init_frame_context(frame_context_t *const context, istream_t *const in, const dictionary_t *const dict); static void free_frame_context(frame_context_t *const context); static void parse_frame_header(frame_header_t *const header, istream_t *const in); static void frame_context_apply_dict(frame_context_t *const ctx, const dictionary_t *const dict); static void decompress_data(frame_context_t *const ctx, ostream_t *const out, istream_t *const in); static void decode_frame(ostream_t *const out, istream_t *const in, const dictionary_t *const dict) { - const u32 magic_number = IO_read_bits(in, 32); + const u32 magic_number = (u32)IO_read_bits(in, 32); // Zstandard frame // // "Magic_Number // // 4 Bytes, little-endian format. Value : 0xFD2FB528" if (magic_number == 0xFD2FB528U) { // ZSTD frame decode_data_frame(out, in, dict); return; } // not a real frame or a skippable frame ERROR("Tried to decode non-ZSTD frame"); } /// Decode a frame that contains compressed data. Not all frames do as there /// are skippable frames. /// See /// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#general-structure-of-zstandard-frame-format static void decode_data_frame(ostream_t *const out, istream_t *const in, const dictionary_t *const dict) { frame_context_t ctx; // Initialize the context that needs to be carried from block to block init_frame_context(&ctx, in, dict); if (ctx.header.frame_content_size != 0 && ctx.header.frame_content_size > out->len) { OUT_SIZE(); } decompress_data(&ctx, out, in); free_frame_context(&ctx); } /// Takes the information provided in the header and dictionary, and initializes /// the context for this frame static void init_frame_context(frame_context_t *const context, istream_t *const in, const dictionary_t *const dict) { // Most fields in context are correct when initialized to 0 memset(context, 0, sizeof(frame_context_t)); // Parse data from the frame header parse_frame_header(&context->header, in); // Set up the offset history for the repeat offset commands context->previous_offsets[0] = 1; context->previous_offsets[1] = 4; context->previous_offsets[2] = 8; // Apply details from the dict if it exists frame_context_apply_dict(context, dict); } static void free_frame_context(frame_context_t *const context) { HUF_free_dtable(&context->literals_dtable); FSE_free_dtable(&context->ll_dtable); FSE_free_dtable(&context->ml_dtable); FSE_free_dtable(&context->of_dtable); memset(context, 0, sizeof(frame_context_t)); } static void parse_frame_header(frame_header_t *const header, istream_t *const in) { // "The first header's byte is called the Frame_Header_Descriptor. It tells // which other fields are present. Decoding this byte is enough to tell the // size of Frame_Header. // // Bit number Field name // 7-6 Frame_Content_Size_flag // 5 Single_Segment_flag // 4 Unused_bit // 3 Reserved_bit // 2 Content_Checksum_flag // 1-0 Dictionary_ID_flag" - const u8 descriptor = IO_read_bits(in, 8); + const u8 descriptor = (u8)IO_read_bits(in, 8); // decode frame header descriptor into flags const u8 frame_content_size_flag = descriptor >> 6; const u8 single_segment_flag = (descriptor >> 5) & 1; const u8 reserved_bit = (descriptor >> 3) & 1; const u8 content_checksum_flag = (descriptor >> 2) & 1; const u8 dictionary_id_flag = descriptor & 3; if (reserved_bit != 0) { CORRUPTION(); } header->single_segment_flag = single_segment_flag; header->content_checksum_flag = content_checksum_flag; // decode window size if (!single_segment_flag) { // "Provides guarantees on maximum back-reference distance that will be // used within compressed data. This information is important for // decoders to allocate enough memory. // // Bit numbers 7-3 2-0 // Field name Exponent Mantissa" - u8 window_descriptor = IO_read_bits(in, 8); + u8 window_descriptor = (u8)IO_read_bits(in, 8); u8 exponent = window_descriptor >> 3; u8 mantissa = window_descriptor & 7; // Use the algorithm from the specification to compute window size // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#window_descriptor size_t window_base = (size_t)1 << (10 + exponent); size_t window_add = (window_base / 8) * mantissa; header->window_size = window_base + window_add; } // decode dictionary id if it exists if (dictionary_id_flag) { // "This is a variable size field, which contains the ID of the // dictionary required to properly decode the frame. Note that this // field is optional. When it's not present, it's up to the caller to // make sure it uses the correct dictionary. Format is little-endian." const int bytes_array[] = {0, 1, 2, 4}; const int bytes = bytes_array[dictionary_id_flag]; - header->dictionary_id = IO_read_bits(in, bytes * 8); + header->dictionary_id = (u32)IO_read_bits(in, bytes * 8); } else { header->dictionary_id = 0; } // decode frame content size if it exists if (single_segment_flag || frame_content_size_flag) { // "This is the original (uncompressed) size. This information is // optional. The Field_Size is provided according to value of // Frame_Content_Size_flag. The Field_Size can be equal to 0 (not // present), 1, 2, 4 or 8 bytes. Format is little-endian." // // if frame_content_size_flag == 0 but single_segment_flag is set, we // still have a 1 byte field const int bytes_array[] = {1, 2, 4, 8}; const int bytes = bytes_array[frame_content_size_flag]; header->frame_content_size = IO_read_bits(in, bytes * 8); if (bytes == 2) { // "When Field_Size is 2, the offset of 256 is added." header->frame_content_size += 256; } } else { header->frame_content_size = 0; } if (single_segment_flag) { // "The Window_Descriptor byte is optional. It is absent when // Single_Segment_flag is set. In this case, the maximum back-reference // distance is the content size itself, which can be any value from 1 to // 2^64-1 bytes (16 EB)." header->window_size = header->frame_content_size; } } /// A dictionary acts as initializing values for the frame context before /// decompression, so we implement it by applying it's predetermined /// tables and content to the context before beginning decompression static void frame_context_apply_dict(frame_context_t *const ctx, const dictionary_t *const dict) { // If the content pointer is NULL then it must be an empty dict if (!dict || !dict->content) return; // If the requested dictionary_id is non-zero, the correct dictionary must // be present if (ctx->header.dictionary_id != 0 && ctx->header.dictionary_id != dict->dictionary_id) { ERROR("Wrong dictionary provided"); } // Copy the dict content to the context for references during sequence // execution ctx->dict_content = dict->content; ctx->dict_content_len = dict->content_size; // If it's a formatted dict copy the precomputed tables in so they can // be used in the table repeat modes if (dict->dictionary_id != 0) { // Deep copy the entropy tables so they can be freed independently of // the dictionary struct HUF_copy_dtable(&ctx->literals_dtable, &dict->literals_dtable); FSE_copy_dtable(&ctx->ll_dtable, &dict->ll_dtable); FSE_copy_dtable(&ctx->of_dtable, &dict->of_dtable); FSE_copy_dtable(&ctx->ml_dtable, &dict->ml_dtable); // Copy the repeated offsets memcpy(ctx->previous_offsets, dict->previous_offsets, sizeof(ctx->previous_offsets)); } } /// Decompress the data from a frame block by block static void decompress_data(frame_context_t *const ctx, ostream_t *const out, istream_t *const in) { // "A frame encapsulates one or multiple blocks. Each block can be // compressed or not, and has a guaranteed maximum content size, which // depends on frame parameters. Unlike frames, each block depends on // previous blocks for proper decoding. However, each block can be // decompressed without waiting for its successor, allowing streaming // operations." int last_block = 0; do { // "Last_Block // // The lowest bit signals if this block is the last one. Frame ends // right after this block. // // Block_Type and Block_Size // // The next 2 bits represent the Block_Type, while the remaining 21 bits // represent the Block_Size. Format is little-endian." - last_block = IO_read_bits(in, 1); - const int block_type = IO_read_bits(in, 2); + last_block = (int)IO_read_bits(in, 1); + const int block_type = (int)IO_read_bits(in, 2); const size_t block_len = IO_read_bits(in, 21); switch (block_type) { case 0: { // "Raw_Block - this is an uncompressed block. Block_Size is the // number of bytes to read and copy." const u8 *const read_ptr = IO_get_read_ptr(in, block_len); u8 *const write_ptr = IO_get_write_ptr(out, block_len); // Copy the raw data into the output memcpy(write_ptr, read_ptr, block_len); ctx->current_total_output += block_len; break; } case 1: { // "RLE_Block - this is a single byte, repeated N times. In which // case, Block_Size is the size to regenerate, while the // "compressed" block is just 1 byte (the byte to repeat)." const u8 *const read_ptr = IO_get_read_ptr(in, 1); u8 *const write_ptr = IO_get_write_ptr(out, block_len); // Copy `block_len` copies of `read_ptr[0]` to the output memset(write_ptr, read_ptr[0], block_len); ctx->current_total_output += block_len; break; } case 2: { // "Compressed_Block - this is a Zstandard compressed block, // detailed in another section of this specification. Block_Size is // the compressed size. // Create a sub-stream for the block istream_t block_stream = IO_make_sub_istream(in, block_len); decompress_block(ctx, out, &block_stream); break; } case 3: // "Reserved - this is not a block. This value cannot be used with // current version of this specification." CORRUPTION(); break; default: IMPOSSIBLE(); } } while (!last_block); if (ctx->header.content_checksum_flag) { // This program does not support checking the checksum, so skip over it // if it's present IO_advance_input(in, 4); } } /******* END FRAME DECODING ***************************************************/ /******* BLOCK DECOMPRESSION **************************************************/ static void decompress_block(frame_context_t *const ctx, ostream_t *const out, istream_t *const in) { // "A compressed block consists of 2 sections : // // Literals_Section // Sequences_Section" // Part 1: decode the literals block u8 *literals = NULL; const size_t literals_size = decode_literals(ctx, in, &literals); // Part 2: decode the sequences block sequence_command_t *sequences = NULL; const size_t num_sequences = decode_sequences(ctx, in, &sequences); // Part 3: combine literals and sequence commands to generate output execute_sequences(ctx, out, literals, literals_size, sequences, num_sequences); free(literals); free(sequences); } /******* END BLOCK DECOMPRESSION **********************************************/ /******* LITERALS DECODING ****************************************************/ static size_t decode_literals_simple(istream_t *const in, u8 **const literals, const int block_type, const int size_format); static size_t decode_literals_compressed(frame_context_t *const ctx, istream_t *const in, u8 **const literals, const int block_type, const int size_format); static void decode_huf_table(HUF_dtable *const dtable, istream_t *const in); static void fse_decode_hufweights(ostream_t *weights, istream_t *const in, int *const num_symbs); static size_t decode_literals(frame_context_t *const ctx, istream_t *const in, u8 **const literals) { // "Literals can be stored uncompressed or compressed using Huffman prefix // codes. When compressed, an optional tree description can be present, // followed by 1 or 4 streams." // // "Literals_Section_Header // // Header is in charge of describing how literals are packed. It's a // byte-aligned variable-size bitfield, ranging from 1 to 5 bytes, using // little-endian convention." // // "Literals_Block_Type // // This field uses 2 lowest bits of first byte, describing 4 different block // types" // // size_format takes between 1 and 2 bits - int block_type = IO_read_bits(in, 2); - int size_format = IO_read_bits(in, 2); + int block_type = (int)IO_read_bits(in, 2); + int size_format = (int)IO_read_bits(in, 2); if (block_type <= 1) { // Raw or RLE literals block return decode_literals_simple(in, literals, block_type, size_format); } else { // Huffman compressed literals return decode_literals_compressed(ctx, in, literals, block_type, size_format); } } /// Decodes literals blocks in raw or RLE form static size_t decode_literals_simple(istream_t *const in, u8 **const literals, const int block_type, const int size_format) { size_t size; switch (size_format) { // These cases are in the form ?0 // In this case, the ? bit is actually part of the size field case 0: case 2: // "Size_Format uses 1 bit. Regenerated_Size uses 5 bits (0-31)." IO_rewind_bits(in, 1); size = IO_read_bits(in, 5); break; case 1: // "Size_Format uses 2 bits. Regenerated_Size uses 12 bits (0-4095)." size = IO_read_bits(in, 12); break; case 3: // "Size_Format uses 2 bits. Regenerated_Size uses 20 bits (0-1048575)." size = IO_read_bits(in, 20); break; default: // Size format is in range 0-3 IMPOSSIBLE(); } if (size > MAX_LITERALS_SIZE) { CORRUPTION(); } *literals = malloc(size); if (!*literals) { BAD_ALLOC(); } switch (block_type) { case 0: { // "Raw_Literals_Block - Literals are stored uncompressed." const u8 *const read_ptr = IO_get_read_ptr(in, size); memcpy(*literals, read_ptr, size); break; } case 1: { // "RLE_Literals_Block - Literals consist of a single byte value repeated N times." const u8 *const read_ptr = IO_get_read_ptr(in, 1); memset(*literals, read_ptr[0], size); break; } default: IMPOSSIBLE(); } return size; } /// Decodes Huffman compressed literals static size_t decode_literals_compressed(frame_context_t *const ctx, istream_t *const in, u8 **const literals, const int block_type, const int size_format) { size_t regenerated_size, compressed_size; // Only size_format=0 has 1 stream, so default to 4 int num_streams = 4; switch (size_format) { case 0: // "A single stream. Both Compressed_Size and Regenerated_Size use 10 // bits (0-1023)." num_streams = 1; // Fall through as it has the same size format + /* fallthrough */ case 1: // "4 streams. Both Compressed_Size and Regenerated_Size use 10 bits // (0-1023)." regenerated_size = IO_read_bits(in, 10); compressed_size = IO_read_bits(in, 10); break; case 2: // "4 streams. Both Compressed_Size and Regenerated_Size use 14 bits // (0-16383)." regenerated_size = IO_read_bits(in, 14); compressed_size = IO_read_bits(in, 14); break; case 3: // "4 streams. Both Compressed_Size and Regenerated_Size use 18 bits // (0-262143)." regenerated_size = IO_read_bits(in, 18); compressed_size = IO_read_bits(in, 18); break; default: // Impossible IMPOSSIBLE(); } - if (regenerated_size > MAX_LITERALS_SIZE || - compressed_size >= regenerated_size) { + if (regenerated_size > MAX_LITERALS_SIZE) { CORRUPTION(); } *literals = malloc(regenerated_size); if (!*literals) { BAD_ALLOC(); } ostream_t lit_stream = IO_make_ostream(*literals, regenerated_size); istream_t huf_stream = IO_make_sub_istream(in, compressed_size); if (block_type == 2) { // Decode the provided Huffman table // "This section is only present when Literals_Block_Type type is // Compressed_Literals_Block (2)." HUF_free_dtable(&ctx->literals_dtable); decode_huf_table(&ctx->literals_dtable, &huf_stream); } else { // If the previous Huffman table is being repeated, ensure it exists if (!ctx->literals_dtable.symbols) { CORRUPTION(); } } size_t symbols_decoded; if (num_streams == 1) { symbols_decoded = HUF_decompress_1stream(&ctx->literals_dtable, &lit_stream, &huf_stream); } else { symbols_decoded = HUF_decompress_4stream(&ctx->literals_dtable, &lit_stream, &huf_stream); } if (symbols_decoded != regenerated_size) { CORRUPTION(); } return regenerated_size; } // Decode the Huffman table description static void decode_huf_table(HUF_dtable *const dtable, istream_t *const in) { // "All literal values from zero (included) to last present one (excluded) // are represented by Weight with values from 0 to Max_Number_of_Bits." // "This is a single byte value (0-255), which describes how to decode the list of weights." const u8 header = IO_read_bits(in, 8); u8 weights[HUF_MAX_SYMBS]; memset(weights, 0, sizeof(weights)); int num_symbs; if (header >= 128) { // "This is a direct representation, where each Weight is written // directly as a 4 bits field (0-15). The full representation occupies // ((Number_of_Symbols+1)/2) bytes, meaning it uses a last full byte // even if Number_of_Symbols is odd. Number_of_Symbols = headerByte - // 127" num_symbs = header - 127; const size_t bytes = (num_symbs + 1) / 2; const u8 *const weight_src = IO_get_read_ptr(in, bytes); for (int i = 0; i < num_symbs; i++) { // "They are encoded forward, 2 // weights to a byte with the first weight taking the top four bits // and the second taking the bottom four (e.g. the following // operations could be used to read the weights: Weight[0] = // (Byte[0] >> 4), Weight[1] = (Byte[0] & 0xf), etc.)." if (i % 2 == 0) { weights[i] = weight_src[i / 2] >> 4; } else { weights[i] = weight_src[i / 2] & 0xf; } } } else { // The weights are FSE encoded, decode them before we can construct the // table istream_t fse_stream = IO_make_sub_istream(in, header); ostream_t weight_stream = IO_make_ostream(weights, HUF_MAX_SYMBS); fse_decode_hufweights(&weight_stream, &fse_stream, &num_symbs); } // Construct the table using the decoded weights HUF_init_dtable_usingweights(dtable, weights, num_symbs); } static void fse_decode_hufweights(ostream_t *weights, istream_t *const in, int *const num_symbs) { const int MAX_ACCURACY_LOG = 7; FSE_dtable dtable; // "An FSE bitstream starts by a header, describing probabilities // distribution. It will create a Decoding Table. For a list of Huffman // weights, maximum accuracy is 7 bits." FSE_decode_header(&dtable, in, MAX_ACCURACY_LOG); // Decode the weights *num_symbs = FSE_decompress_interleaved2(&dtable, weights, in); FSE_free_dtable(&dtable); } /******* END LITERALS DECODING ************************************************/ /******* SEQUENCE DECODING ****************************************************/ /// The combination of FSE states needed to decode sequences typedef struct { FSE_dtable ll_table; FSE_dtable of_table; FSE_dtable ml_table; u16 ll_state; u16 of_state; u16 ml_state; } sequence_states_t; /// Different modes to signal to decode_seq_tables what to do typedef enum { seq_literal_length = 0, seq_offset = 1, seq_match_length = 2, } seq_part_t; typedef enum { seq_predefined = 0, seq_rle = 1, seq_fse = 2, seq_repeat = 3, } seq_mode_t; /// The predefined FSE distribution tables for `seq_predefined` mode static const i16 SEQ_LITERAL_LENGTH_DEFAULT_DIST[36] = { 4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1, -1, -1, -1, -1}; static const i16 SEQ_OFFSET_DEFAULT_DIST[29] = { 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1}; static const i16 SEQ_MATCH_LENGTH_DEFAULT_DIST[53] = { 1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1}; /// The sequence decoding baseline and number of additional bits to read/add /// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#the-codes-for-literals-lengths-match-lengths-and-offsets static const u32 SEQ_LITERAL_LENGTH_BASELINES[36] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 22, 24, 28, 32, 40, - 48, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65538}; + 48, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536}; static const u8 SEQ_LITERAL_LENGTH_EXTRA_BITS[36] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}; static const u32 SEQ_MATCH_LENGTH_BASELINES[53] = { 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 39, 41, 43, 47, 51, 59, 67, 83, 99, 131, 259, 515, 1027, 2051, 4099, 8195, 16387, 32771, 65539}; static const u8 SEQ_MATCH_LENGTH_EXTRA_BITS[53] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}; /// Offset decoding is simpler so we just need a maximum code value -static const u8 SEQ_MAX_CODES[3] = {35, -1, 52}; +static const u8 SEQ_MAX_CODES[3] = {35, (u8)-1, 52}; static void decompress_sequences(frame_context_t *const ctx, istream_t *const in, sequence_command_t *const sequences, const size_t num_sequences); static sequence_command_t decode_sequence(sequence_states_t *const state, const u8 *const src, i64 *const offset); static void decode_seq_table(FSE_dtable *const table, istream_t *const in, const seq_part_t type, const seq_mode_t mode); static size_t decode_sequences(frame_context_t *const ctx, istream_t *in, sequence_command_t **const sequences) { // "A compressed block is a succession of sequences . A sequence is a // literal copy command, followed by a match copy command. A literal copy // command specifies a length. It is the number of bytes to be copied (or // extracted) from the literal section. A match copy command specifies an // offset and a length. The offset gives the position to copy from, which // can be within a previous block." size_t num_sequences; // "Number_of_Sequences // // This is a variable size field using between 1 and 3 bytes. Let's call its // first byte byte0." u8 header = IO_read_bits(in, 8); if (header == 0) { // "There are no sequences. The sequence section stops there. // Regenerated content is defined entirely by literals section." *sequences = NULL; return 0; } else if (header < 128) { // "Number_of_Sequences = byte0 . Uses 1 byte." num_sequences = header; } else if (header < 255) { // "Number_of_Sequences = ((byte0-128) << 8) + byte1 . Uses 2 bytes." num_sequences = ((header - 128) << 8) + IO_read_bits(in, 8); } else { // "Number_of_Sequences = byte1 + (byte2<<8) + 0x7F00 . Uses 3 bytes." num_sequences = IO_read_bits(in, 16) + 0x7F00; } *sequences = malloc(num_sequences * sizeof(sequence_command_t)); if (!*sequences) { BAD_ALLOC(); } decompress_sequences(ctx, in, *sequences, num_sequences); return num_sequences; } /// Decompress the FSE encoded sequence commands static void decompress_sequences(frame_context_t *const ctx, istream_t *in, sequence_command_t *const sequences, const size_t num_sequences) { // "The Sequences_Section regroup all symbols required to decode commands. // There are 3 symbol types : literals lengths, offsets and match lengths. // They are encoded together, interleaved, in a single bitstream." // "Symbol compression modes // // This is a single byte, defining the compression mode of each symbol // type." // // Bit number : Field name // 7-6 : Literals_Lengths_Mode // 5-4 : Offsets_Mode // 3-2 : Match_Lengths_Mode // 1-0 : Reserved u8 compression_modes = IO_read_bits(in, 8); if ((compression_modes & 3) != 0) { // Reserved bits set CORRUPTION(); } // "Following the header, up to 3 distribution tables can be described. When // present, they are in this order : // // Literals lengths // Offsets // Match Lengths" // Update the tables we have stored in the context decode_seq_table(&ctx->ll_dtable, in, seq_literal_length, (compression_modes >> 6) & 3); decode_seq_table(&ctx->of_dtable, in, seq_offset, (compression_modes >> 4) & 3); decode_seq_table(&ctx->ml_dtable, in, seq_match_length, (compression_modes >> 2) & 3); sequence_states_t states; // Initialize the decoding tables { states.ll_table = ctx->ll_dtable; states.of_table = ctx->of_dtable; states.ml_table = ctx->ml_dtable; } const size_t len = IO_istream_len(in); const u8 *const src = IO_get_read_ptr(in, len); // "After writing the last bit containing information, the compressor writes // a single 1-bit and then fills the byte with 0-7 0 bits of padding." const int padding = 8 - highest_set_bit(src[len - 1]); // The offset starts at the end because FSE streams are read backwards - i64 bit_offset = len * 8 - padding; + i64 bit_offset = (i64)(len * 8 - (size_t)padding); // "The bitstream starts with initial state values, each using the required // number of bits in their respective accuracy, decoded previously from // their normalized distribution. // // It starts by Literals_Length_State, followed by Offset_State, and finally // Match_Length_State." FSE_init_state(&states.ll_table, &states.ll_state, src, &bit_offset); FSE_init_state(&states.of_table, &states.of_state, src, &bit_offset); FSE_init_state(&states.ml_table, &states.ml_state, src, &bit_offset); for (size_t i = 0; i < num_sequences; i++) { // Decode sequences one by one sequences[i] = decode_sequence(&states, src, &bit_offset); } if (bit_offset != 0) { CORRUPTION(); } } // Decode a single sequence and update the state static sequence_command_t decode_sequence(sequence_states_t *const states, const u8 *const src, i64 *const offset) { // "Each symbol is a code in its own context, which specifies Baseline and // Number_of_Bits to add. Codes are FSE compressed, and interleaved with raw // additional bits in the same bitstream." // Decode symbols, but don't update states const u8 of_code = FSE_peek_symbol(&states->of_table, states->of_state); const u8 ll_code = FSE_peek_symbol(&states->ll_table, states->ll_state); const u8 ml_code = FSE_peek_symbol(&states->ml_table, states->ml_state); // Offset doesn't need a max value as it's not decoded using a table if (ll_code > SEQ_MAX_CODES[seq_literal_length] || ml_code > SEQ_MAX_CODES[seq_match_length]) { CORRUPTION(); } // Read the interleaved bits sequence_command_t seq; // "Decoding starts by reading the Number_of_Bits required to decode Offset. // It then does the same for Match_Length, and then for Literals_Length." seq.offset = ((u32)1 << of_code) + STREAM_read_bits(src, of_code, offset); seq.match_length = SEQ_MATCH_LENGTH_BASELINES[ml_code] + STREAM_read_bits(src, SEQ_MATCH_LENGTH_EXTRA_BITS[ml_code], offset); seq.literal_length = SEQ_LITERAL_LENGTH_BASELINES[ll_code] + STREAM_read_bits(src, SEQ_LITERAL_LENGTH_EXTRA_BITS[ll_code], offset); // "If it is not the last sequence in the block, the next operation is to // update states. Using the rules pre-calculated in the decoding tables, // Literals_Length_State is updated, followed by Match_Length_State, and // then Offset_State." // If the stream is complete don't read bits to update state if (*offset != 0) { FSE_update_state(&states->ll_table, &states->ll_state, src, offset); FSE_update_state(&states->ml_table, &states->ml_state, src, offset); FSE_update_state(&states->of_table, &states->of_state, src, offset); } return seq; } /// Given a sequence part and table mode, decode the FSE distribution /// Errors if the mode is `seq_repeat` without a pre-existing table in `table` static void decode_seq_table(FSE_dtable *const table, istream_t *const in, const seq_part_t type, const seq_mode_t mode) { // Constant arrays indexed by seq_part_t const i16 *const default_distributions[] = {SEQ_LITERAL_LENGTH_DEFAULT_DIST, SEQ_OFFSET_DEFAULT_DIST, SEQ_MATCH_LENGTH_DEFAULT_DIST}; const size_t default_distribution_lengths[] = {36, 29, 53}; const size_t default_distribution_accuracies[] = {6, 5, 6}; const size_t max_accuracies[] = {9, 8, 9}; if (mode != seq_repeat) { // Free old one before overwriting FSE_free_dtable(table); } switch (mode) { case seq_predefined: { // "Predefined_Mode : uses a predefined distribution table." const i16 *distribution = default_distributions[type]; const size_t symbs = default_distribution_lengths[type]; const size_t accuracy_log = default_distribution_accuracies[type]; FSE_init_dtable(table, distribution, symbs, accuracy_log); break; } case seq_rle: { // "RLE_Mode : it's a single code, repeated Number_of_Sequences times." const u8 symb = IO_get_read_ptr(in, 1)[0]; FSE_init_dtable_rle(table, symb); break; } case seq_fse: { // "FSE_Compressed_Mode : standard FSE compression. A distribution table // will be present " FSE_decode_header(table, in, max_accuracies[type]); break; } case seq_repeat: // "Repeat_Mode : re-use distribution table from previous compressed // block." // Nothing to do here, table will be unchanged if (!table->symbols) { // This mode is invalid if we don't already have a table CORRUPTION(); } break; default: // Impossible, as mode is from 0-3 IMPOSSIBLE(); break; } } /******* END SEQUENCE DECODING ************************************************/ /******* SEQUENCE EXECUTION ***************************************************/ static void execute_sequences(frame_context_t *const ctx, ostream_t *const out, const u8 *const literals, const size_t literals_len, const sequence_command_t *const sequences, const size_t num_sequences) { istream_t litstream = IO_make_istream(literals, literals_len); u64 *const offset_hist = ctx->previous_offsets; size_t total_output = ctx->current_total_output; for (size_t i = 0; i < num_sequences; i++) { const sequence_command_t seq = sequences[i]; { const u32 literals_size = copy_literals(seq.literal_length, &litstream, out); total_output += literals_size; } size_t const offset = compute_offset(seq, offset_hist); size_t const match_length = seq.match_length; execute_match_copy(ctx, offset, match_length, total_output, out); total_output += match_length; } // Copy any leftover literals { size_t len = IO_istream_len(&litstream); copy_literals(len, &litstream, out); total_output += len; } ctx->current_total_output = total_output; } static u32 copy_literals(const size_t literal_length, istream_t *litstream, ostream_t *const out) { // If the sequence asks for more literals than are left, the // sequence must be corrupted if (literal_length > IO_istream_len(litstream)) { CORRUPTION(); } u8 *const write_ptr = IO_get_write_ptr(out, literal_length); const u8 *const read_ptr = IO_get_read_ptr(litstream, literal_length); // Copy literals to output memcpy(write_ptr, read_ptr, literal_length); return literal_length; } static size_t compute_offset(sequence_command_t seq, u64 *const offset_hist) { size_t offset; // Offsets are special, we need to handle the repeat offsets if (seq.offset <= 3) { // "The first 3 values define a repeated offset and we will call // them Repeated_Offset1, Repeated_Offset2, and Repeated_Offset3. // They are sorted in recency order, with Repeated_Offset1 meaning // 'most recent one'". // Use 0 indexing for the array u32 idx = seq.offset - 1; if (seq.literal_length == 0) { // "There is an exception though, when current sequence's // literals length is 0. In this case, repeated offsets are // shifted by one, so Repeated_Offset1 becomes Repeated_Offset2, // Repeated_Offset2 becomes Repeated_Offset3, and // Repeated_Offset3 becomes Repeated_Offset1 - 1_byte." idx++; } if (idx == 0) { offset = offset_hist[0]; } else { // If idx == 3 then literal length was 0 and the offset was 3, // as per the exception listed above offset = idx < 3 ? offset_hist[idx] : offset_hist[0] - 1; // If idx == 1 we don't need to modify offset_hist[2], since // we're using the second-most recent code if (idx > 1) { offset_hist[2] = offset_hist[1]; } offset_hist[1] = offset_hist[0]; offset_hist[0] = offset; } } else { // When it's not a repeat offset: // "if (Offset_Value > 3) offset = Offset_Value - 3;" offset = seq.offset - 3; // Shift back history offset_hist[2] = offset_hist[1]; offset_hist[1] = offset_hist[0]; offset_hist[0] = offset; } return offset; } static void execute_match_copy(frame_context_t *const ctx, size_t offset, size_t match_length, size_t total_output, ostream_t *const out) { u8 *write_ptr = IO_get_write_ptr(out, match_length); if (total_output <= ctx->header.window_size) { // In this case offset might go back into the dictionary if (offset > total_output + ctx->dict_content_len) { // The offset goes beyond even the dictionary CORRUPTION(); } if (offset > total_output) { // "The rest of the dictionary is its content. The content act // as a "past" in front of data to compress or decompress, so it // can be referenced in sequence commands." const size_t dict_copy = MIN(offset - total_output, match_length); const size_t dict_offset = ctx->dict_content_len - (offset - total_output); memcpy(write_ptr, ctx->dict_content + dict_offset, dict_copy); write_ptr += dict_copy; match_length -= dict_copy; } } else if (offset > ctx->header.window_size) { CORRUPTION(); } // We must copy byte by byte because the match length might be larger // than the offset // ex: if the output so far was "abc", a command with offset=3 and // match_length=6 would produce "abcabcabc" as the new output for (size_t j = 0; j < match_length; j++) { *write_ptr = *(write_ptr - offset); write_ptr++; } } /******* END SEQUENCE EXECUTION ***********************************************/ /******* OUTPUT SIZE COUNTING *************************************************/ /// Get the decompressed size of an input stream so memory can be allocated in /// advance. /// This implementation assumes `src` points to a single ZSTD-compressed frame size_t ZSTD_get_decompressed_size(const void *src, const size_t src_len) { istream_t in = IO_make_istream(src, src_len); // get decompressed size from ZSTD frame header { - const u32 magic_number = IO_read_bits(&in, 32); + const u32 magic_number = (u32)IO_read_bits(&in, 32); if (magic_number == 0xFD2FB528U) { // ZSTD frame frame_header_t header; parse_frame_header(&header, &in); if (header.frame_content_size == 0 && !header.single_segment_flag) { // Content size not provided, we can't tell - return -1; + return (size_t)-1; } return header.frame_content_size; } else { // not a real frame or skippable frame ERROR("ZSTD frame magic number did not match"); } } } /******* END OUTPUT SIZE COUNTING *********************************************/ /******* DICTIONARY PARSING ***************************************************/ #define DICT_SIZE_ERROR() ERROR("Dictionary size cannot be less than 8 bytes") #define NULL_SRC() ERROR("Tried to create dictionary with pointer to null src"); dictionary_t* create_dictionary() { dictionary_t* dict = calloc(1, sizeof(dictionary_t)); if (!dict) { BAD_ALLOC(); } return dict; } static void init_dictionary_content(dictionary_t *const dict, istream_t *const in); void parse_dictionary(dictionary_t *const dict, const void *src, size_t src_len) { const u8 *byte_src = (const u8 *)src; memset(dict, 0, sizeof(dictionary_t)); if (src == NULL) { /* cannot initialize dictionary with null src */ NULL_SRC(); } if (src_len < 8) { DICT_SIZE_ERROR(); } istream_t in = IO_make_istream(byte_src, src_len); const u32 magic_number = IO_read_bits(&in, 32); if (magic_number != 0xEC30A437) { // raw content dict IO_rewind_bits(&in, 32); init_dictionary_content(dict, &in); return; } dict->dictionary_id = IO_read_bits(&in, 32); // "Entropy_Tables : following the same format as the tables in compressed // blocks. They are stored in following order : Huffman tables for literals, // FSE table for offsets, FSE table for match lengths, and FSE table for // literals lengths. It's finally followed by 3 offset values, populating // recent offsets (instead of using {1,4,8}), stored in order, 4-bytes // little-endian each, for a total of 12 bytes. Each recent offset must have // a value < dictionary size." decode_huf_table(&dict->literals_dtable, &in); decode_seq_table(&dict->of_dtable, &in, seq_offset, seq_fse); decode_seq_table(&dict->ml_dtable, &in, seq_match_length, seq_fse); decode_seq_table(&dict->ll_dtable, &in, seq_literal_length, seq_fse); // Read in the previous offset history dict->previous_offsets[0] = IO_read_bits(&in, 32); dict->previous_offsets[1] = IO_read_bits(&in, 32); dict->previous_offsets[2] = IO_read_bits(&in, 32); // Ensure the provided offsets aren't too large // "Each recent offset must have a value < dictionary size." for (int i = 0; i < 3; i++) { if (dict->previous_offsets[i] > src_len) { ERROR("Dictionary corrupted"); } } // "Content : The rest of the dictionary is its content. The content act as // a "past" in front of data to compress or decompress, so it can be // referenced in sequence commands." init_dictionary_content(dict, &in); } static void init_dictionary_content(dictionary_t *const dict, istream_t *const in) { // Copy in the content dict->content_size = IO_istream_len(in); dict->content = malloc(dict->content_size); if (!dict->content) { BAD_ALLOC(); } const u8 *const content = IO_get_read_ptr(in, dict->content_size); memcpy(dict->content, content, dict->content_size); } /// Free an allocated dictionary void free_dictionary(dictionary_t *const dict) { HUF_free_dtable(&dict->literals_dtable); FSE_free_dtable(&dict->ll_dtable); FSE_free_dtable(&dict->of_dtable); FSE_free_dtable(&dict->ml_dtable); free(dict->content); memset(dict, 0, sizeof(dictionary_t)); free(dict); } /******* END DICTIONARY PARSING ***********************************************/ /******* IO STREAM OPERATIONS *************************************************/ -#define UNALIGNED() ERROR("Attempting to operate on a non-byte aligned stream") + /// Reads `num` bits from a bitstream, and updates the internal offset static inline u64 IO_read_bits(istream_t *const in, const int num_bits) { if (num_bits > 64 || num_bits <= 0) { ERROR("Attempt to read an invalid number of bits"); } const size_t bytes = (num_bits + in->bit_offset + 7) / 8; const size_t full_bytes = (num_bits + in->bit_offset) / 8; if (bytes > in->len) { INP_SIZE(); } const u64 result = read_bits_LE(in->ptr, num_bits, in->bit_offset); in->bit_offset = (num_bits + in->bit_offset) % 8; in->ptr += full_bytes; in->len -= full_bytes; return result; } /// If a non-zero number of bits have been read from the current byte, advance /// the offset to the next byte static inline void IO_rewind_bits(istream_t *const in, int num_bits) { if (num_bits < 0) { ERROR("Attempting to rewind stream by a negative number of bits"); } // move the offset back by `num_bits` bits const int new_offset = in->bit_offset - num_bits; // determine the number of whole bytes we have to rewind, rounding up to an // integer number (e.g. if `new_offset == -5`, `bytes == 1`) const i64 bytes = -(new_offset - 7) / 8; in->ptr -= bytes; in->len += bytes; // make sure the resulting `bit_offset` is positive, as mod in C does not // convert numbers from negative to positive (e.g. -22 % 8 == -6) in->bit_offset = ((new_offset % 8) + 8) % 8; } /// If the remaining bits in a byte will be unused, advance to the end of the /// byte static inline void IO_align_stream(istream_t *const in) { if (in->bit_offset != 0) { if (in->len == 0) { INP_SIZE(); } in->ptr++; in->len--; in->bit_offset = 0; } } /// Write the given byte into the output stream static inline void IO_write_byte(ostream_t *const out, u8 symb) { if (out->len == 0) { OUT_SIZE(); } out->ptr[0] = symb; out->ptr++; out->len--; } /// Returns the number of bytes left to be read in this stream. The stream must /// be byte aligned. static inline size_t IO_istream_len(const istream_t *const in) { return in->len; } /// Returns a pointer where `len` bytes can be read, and advances the internal /// state. The stream must be byte aligned. static inline const u8 *IO_get_read_ptr(istream_t *const in, size_t len) { if (len > in->len) { INP_SIZE(); } if (in->bit_offset != 0) { - UNALIGNED(); + ERROR("Attempting to operate on a non-byte aligned stream"); } const u8 *const ptr = in->ptr; in->ptr += len; in->len -= len; return ptr; } /// Returns a pointer to write `len` bytes to, and advances the internal state static inline u8 *IO_get_write_ptr(ostream_t *const out, size_t len) { if (len > out->len) { OUT_SIZE(); } u8 *const ptr = out->ptr; out->ptr += len; out->len -= len; return ptr; } /// Advance the inner state by `len` bytes static inline void IO_advance_input(istream_t *const in, size_t len) { if (len > in->len) { INP_SIZE(); } if (in->bit_offset != 0) { - UNALIGNED(); + ERROR("Attempting to operate on a non-byte aligned stream"); } in->ptr += len; in->len -= len; } /// Returns an `ostream_t` constructed from the given pointer and length static inline ostream_t IO_make_ostream(u8 *out, size_t len) { return (ostream_t) { out, len }; } /// Returns an `istream_t` constructed from the given pointer and length static inline istream_t IO_make_istream(const u8 *in, size_t len) { return (istream_t) { in, len, 0 }; } /// Returns an `istream_t` with the same base as `in`, and length `len` /// Then, advance `in` to account for the consumed bytes /// `in` must be byte aligned static inline istream_t IO_make_sub_istream(istream_t *const in, size_t len) { // Consume `len` bytes of the parent stream const u8 *const ptr = IO_get_read_ptr(in, len); // Make a substream using the pointer to those `len` bytes return IO_make_istream(ptr, len); } /******* END IO STREAM OPERATIONS *********************************************/ /******* BITSTREAM OPERATIONS *************************************************/ /// Read `num` bits (up to 64) from `src + offset`, where `offset` is in bits static inline u64 read_bits_LE(const u8 *src, const int num_bits, const size_t offset) { if (num_bits > 64) { ERROR("Attempt to read an invalid number of bits"); } // Skip over bytes that aren't in range src += offset / 8; size_t bit_offset = offset % 8; u64 res = 0; int shift = 0; int left = num_bits; while (left > 0) { u64 mask = left >= 8 ? 0xff : (((u64)1 << left) - 1); // Read the next byte, shift it to account for the offset, and then mask // out the top part if we don't need all the bits res += (((u64)*src++ >> bit_offset) & mask) << shift; shift += 8 - bit_offset; left -= 8 - bit_offset; bit_offset = 0; } return res; } /// Read bits from the end of a HUF or FSE bitstream. `offset` is in bits, so /// it updates `offset` to `offset - bits`, and then reads `bits` bits from /// `src + offset`. If the offset becomes negative, the extra bits at the /// bottom are filled in with `0` bits instead of reading from before `src`. static inline u64 STREAM_read_bits(const u8 *const src, const int bits, i64 *const offset) { *offset = *offset - bits; size_t actual_off = *offset; size_t actual_bits = bits; // Don't actually read bits from before the start of src, so if `*offset < // 0` fix actual_off and actual_bits to reflect the quantity to read if (*offset < 0) { actual_bits += *offset; actual_off = 0; } u64 res = read_bits_LE(src, actual_bits, actual_off); if (*offset < 0) { // Fill in the bottom "overflowed" bits with 0's res = -*offset >= 64 ? 0 : (res << -*offset); } return res; } /******* END BITSTREAM OPERATIONS *********************************************/ /******* BIT COUNTING OPERATIONS **********************************************/ /// Returns `x`, where `2^x` is the largest power of 2 less than or equal to /// `num`, or `-1` if `num == 0`. static inline int highest_set_bit(const u64 num) { for (int i = 63; i >= 0; i--) { if (((u64)1 << i) <= num) { return i; } } return -1; } /******* END BIT COUNTING OPERATIONS ******************************************/ /******* HUFFMAN PRIMITIVES ***************************************************/ static inline u8 HUF_decode_symbol(const HUF_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { // Look up the symbol and number of bits to read const u8 symb = dtable->symbols[*state]; const u8 bits = dtable->num_bits[*state]; const u16 rest = STREAM_read_bits(src, bits, offset); // Shift `bits` bits out of the state, keeping the low order bits that // weren't necessary to determine this symbol. Then add in the new bits // read from the stream. *state = ((*state << bits) + rest) & (((u16)1 << dtable->max_bits) - 1); return symb; } static inline void HUF_init_state(const HUF_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { // Read in a full `dtable->max_bits` bits to initialize the state const u8 bits = dtable->max_bits; *state = STREAM_read_bits(src, bits, offset); } static size_t HUF_decompress_1stream(const HUF_dtable *const dtable, ostream_t *const out, istream_t *const in) { const size_t len = IO_istream_len(in); if (len == 0) { INP_SIZE(); } const u8 *const src = IO_get_read_ptr(in, len); // "Each bitstream must be read backward, that is starting from the end down // to the beginning. Therefore it's necessary to know the size of each // bitstream. // // It's also necessary to know exactly which bit is the latest. This is // detected by a final bit flag : the highest bit of latest byte is a // final-bit-flag. Consequently, a last byte of 0 is not possible. And the // final-bit-flag itself is not part of the useful bitstream. Hence, the // last byte contains between 0 and 7 useful bits." const int padding = 8 - highest_set_bit(src[len - 1]); // Offset starts at the end because HUF streams are read backwards i64 bit_offset = len * 8 - padding; u16 state; HUF_init_state(dtable, &state, src, &bit_offset); size_t symbols_written = 0; while (bit_offset > -dtable->max_bits) { // Iterate over the stream, decoding one symbol at a time IO_write_byte(out, HUF_decode_symbol(dtable, &state, src, &bit_offset)); symbols_written++; } // "The process continues up to reading the required number of symbols per // stream. If a bitstream is not entirely and exactly consumed, hence // reaching exactly its beginning position with all bits consumed, the // decoding process is considered faulty." // When all symbols have been decoded, the final state value shouldn't have // any data from the stream, so it should have "read" dtable->max_bits from // before the start of `src` // Therefore `offset`, the edge to start reading new bits at, should be // dtable->max_bits before the start of the stream if (bit_offset != -dtable->max_bits) { CORRUPTION(); } return symbols_written; } static size_t HUF_decompress_4stream(const HUF_dtable *const dtable, ostream_t *const out, istream_t *const in) { // "Compressed size is provided explicitly : in the 4-streams variant, // bitstreams are preceded by 3 unsigned little-endian 16-bits values. Each // value represents the compressed size of one stream, in order. The last // stream size is deducted from total compressed size and from previously // decoded stream sizes" const size_t csize1 = IO_read_bits(in, 16); const size_t csize2 = IO_read_bits(in, 16); const size_t csize3 = IO_read_bits(in, 16); istream_t in1 = IO_make_sub_istream(in, csize1); istream_t in2 = IO_make_sub_istream(in, csize2); istream_t in3 = IO_make_sub_istream(in, csize3); istream_t in4 = IO_make_sub_istream(in, IO_istream_len(in)); size_t total_output = 0; // Decode each stream independently for simplicity // If we wanted to we could decode all 4 at the same time for speed, // utilizing more execution units total_output += HUF_decompress_1stream(dtable, out, &in1); total_output += HUF_decompress_1stream(dtable, out, &in2); total_output += HUF_decompress_1stream(dtable, out, &in3); total_output += HUF_decompress_1stream(dtable, out, &in4); return total_output; } /// Initializes a Huffman table using canonical Huffman codes /// For more explanation on canonical Huffman codes see /// http://www.cs.uofs.edu/~mccloske/courses/cmps340/huff_canonical_dec2015.html /// Codes within a level are allocated in symbol order (i.e. smaller symbols get /// earlier codes) static void HUF_init_dtable(HUF_dtable *const table, const u8 *const bits, const int num_symbs) { memset(table, 0, sizeof(HUF_dtable)); if (num_symbs > HUF_MAX_SYMBS) { ERROR("Too many symbols for Huffman"); } u8 max_bits = 0; u16 rank_count[HUF_MAX_BITS + 1]; memset(rank_count, 0, sizeof(rank_count)); // Count the number of symbols for each number of bits, and determine the // depth of the tree for (int i = 0; i < num_symbs; i++) { if (bits[i] > HUF_MAX_BITS) { ERROR("Huffman table depth too large"); } max_bits = MAX(max_bits, bits[i]); rank_count[bits[i]]++; } const size_t table_size = 1 << max_bits; table->max_bits = max_bits; table->symbols = malloc(table_size); table->num_bits = malloc(table_size); if (!table->symbols || !table->num_bits) { free(table->symbols); free(table->num_bits); BAD_ALLOC(); } // "Symbols are sorted by Weight. Within same Weight, symbols keep natural // order. Symbols with a Weight of zero are removed. Then, starting from // lowest weight, prefix codes are distributed in order." u32 rank_idx[HUF_MAX_BITS + 1]; // Initialize the starting codes for each rank (number of bits) rank_idx[max_bits] = 0; for (int i = max_bits; i >= 1; i--) { rank_idx[i - 1] = rank_idx[i] + rank_count[i] * (1 << (max_bits - i)); // The entire range takes the same number of bits so we can memset it memset(&table->num_bits[rank_idx[i]], i, rank_idx[i - 1] - rank_idx[i]); } if (rank_idx[0] != table_size) { CORRUPTION(); } // Allocate codes and fill in the table for (int i = 0; i < num_symbs; i++) { if (bits[i] != 0) { // Allocate a code for this symbol and set its range in the table const u16 code = rank_idx[bits[i]]; // Since the code doesn't care about the bottom `max_bits - bits[i]` // bits of state, it gets a range that spans all possible values of // the lower bits const u16 len = 1 << (max_bits - bits[i]); memset(&table->symbols[code], i, len); rank_idx[bits[i]] += len; } } } static void HUF_init_dtable_usingweights(HUF_dtable *const table, const u8 *const weights, const int num_symbs) { // +1 because the last weight is not transmitted in the header if (num_symbs + 1 > HUF_MAX_SYMBS) { ERROR("Too many symbols for Huffman"); } u8 bits[HUF_MAX_SYMBS]; u64 weight_sum = 0; for (int i = 0; i < num_symbs; i++) { // Weights are in the same range as bit count if (weights[i] > HUF_MAX_BITS) { CORRUPTION(); } weight_sum += weights[i] > 0 ? (u64)1 << (weights[i] - 1) : 0; } // Find the first power of 2 larger than the sum const int max_bits = highest_set_bit(weight_sum) + 1; const u64 left_over = ((u64)1 << max_bits) - weight_sum; // If the left over isn't a power of 2, the weights are invalid if (left_over & (left_over - 1)) { CORRUPTION(); } // left_over is used to find the last weight as it's not transmitted // by inverting 2^(weight - 1) we can determine the value of last_weight const int last_weight = highest_set_bit(left_over) + 1; for (int i = 0; i < num_symbs; i++) { // "Number_of_Bits = Number_of_Bits ? Max_Number_of_Bits + 1 - Weight : 0" bits[i] = weights[i] > 0 ? (max_bits + 1 - weights[i]) : 0; } bits[num_symbs] = max_bits + 1 - last_weight; // Last weight is always non-zero HUF_init_dtable(table, bits, num_symbs + 1); } static void HUF_free_dtable(HUF_dtable *const dtable) { free(dtable->symbols); free(dtable->num_bits); memset(dtable, 0, sizeof(HUF_dtable)); } static void HUF_copy_dtable(HUF_dtable *const dst, const HUF_dtable *const src) { if (src->max_bits == 0) { memset(dst, 0, sizeof(HUF_dtable)); return; } const size_t size = (size_t)1 << src->max_bits; dst->max_bits = src->max_bits; dst->symbols = malloc(size); dst->num_bits = malloc(size); if (!dst->symbols || !dst->num_bits) { BAD_ALLOC(); } memcpy(dst->symbols, src->symbols, size); memcpy(dst->num_bits, src->num_bits, size); } /******* END HUFFMAN PRIMITIVES ***********************************************/ /******* FSE PRIMITIVES *******************************************************/ /// For more description of FSE see /// https://github.com/Cyan4973/FiniteStateEntropy/ /// Allow a symbol to be decoded without updating state static inline u8 FSE_peek_symbol(const FSE_dtable *const dtable, const u16 state) { return dtable->symbols[state]; } /// Consumes bits from the input and uses the current state to determine the /// next state static inline void FSE_update_state(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { const u8 bits = dtable->num_bits[*state]; const u16 rest = STREAM_read_bits(src, bits, offset); *state = dtable->new_state_base[*state] + rest; } /// Decodes a single FSE symbol and updates the offset static inline u8 FSE_decode_symbol(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { const u8 symb = FSE_peek_symbol(dtable, *state); FSE_update_state(dtable, state, src, offset); return symb; } static inline void FSE_init_state(const FSE_dtable *const dtable, u16 *const state, const u8 *const src, i64 *const offset) { // Read in a full `accuracy_log` bits to initialize the state const u8 bits = dtable->accuracy_log; *state = STREAM_read_bits(src, bits, offset); } static size_t FSE_decompress_interleaved2(const FSE_dtable *const dtable, ostream_t *const out, istream_t *const in) { const size_t len = IO_istream_len(in); if (len == 0) { INP_SIZE(); } const u8 *const src = IO_get_read_ptr(in, len); // "Each bitstream must be read backward, that is starting from the end down // to the beginning. Therefore it's necessary to know the size of each // bitstream. // // It's also necessary to know exactly which bit is the latest. This is // detected by a final bit flag : the highest bit of latest byte is a // final-bit-flag. Consequently, a last byte of 0 is not possible. And the // final-bit-flag itself is not part of the useful bitstream. Hence, the // last byte contains between 0 and 7 useful bits." const int padding = 8 - highest_set_bit(src[len - 1]); i64 offset = len * 8 - padding; u16 state1, state2; // "The first state (State1) encodes the even indexed symbols, and the // second (State2) encodes the odd indexes. State1 is initialized first, and // then State2, and they take turns decoding a single symbol and updating // their state." FSE_init_state(dtable, &state1, src, &offset); FSE_init_state(dtable, &state2, src, &offset); // Decode until we overflow the stream // Since we decode in reverse order, overflowing the stream is offset going // negative size_t symbols_written = 0; while (1) { // "The number of symbols to decode is determined by tracking bitStream // overflow condition: If updating state after decoding a symbol would // require more bits than remain in the stream, it is assumed the extra // bits are 0. Then, the symbols for each of the final states are // decoded and the process is complete." IO_write_byte(out, FSE_decode_symbol(dtable, &state1, src, &offset)); symbols_written++; if (offset < 0) { // There's still a symbol to decode in state2 IO_write_byte(out, FSE_peek_symbol(dtable, state2)); symbols_written++; break; } IO_write_byte(out, FSE_decode_symbol(dtable, &state2, src, &offset)); symbols_written++; if (offset < 0) { // There's still a symbol to decode in state1 IO_write_byte(out, FSE_peek_symbol(dtable, state1)); symbols_written++; break; } } return symbols_written; } static void FSE_init_dtable(FSE_dtable *const dtable, const i16 *const norm_freqs, const int num_symbs, const int accuracy_log) { if (accuracy_log > FSE_MAX_ACCURACY_LOG) { ERROR("FSE accuracy too large"); } if (num_symbs > FSE_MAX_SYMBS) { ERROR("Too many symbols for FSE"); } dtable->accuracy_log = accuracy_log; const size_t size = (size_t)1 << accuracy_log; dtable->symbols = malloc(size * sizeof(u8)); dtable->num_bits = malloc(size * sizeof(u8)); dtable->new_state_base = malloc(size * sizeof(u16)); if (!dtable->symbols || !dtable->num_bits || !dtable->new_state_base) { BAD_ALLOC(); } // Used to determine how many bits need to be read for each state, // and where the destination range should start // Needs to be u16 because max value is 2 * max number of symbols, // which can be larger than a byte can store u16 state_desc[FSE_MAX_SYMBS]; // "Symbols are scanned in their natural order for "less than 1" // probabilities. Symbols with this probability are being attributed a // single cell, starting from the end of the table. These symbols define a // full state reset, reading Accuracy_Log bits." int high_threshold = size; for (int s = 0; s < num_symbs; s++) { // Scan for low probability symbols to put at the top if (norm_freqs[s] == -1) { dtable->symbols[--high_threshold] = s; state_desc[s] = 1; } } // "All remaining symbols are sorted in their natural order. Starting from // symbol 0 and table position 0, each symbol gets attributed as many cells // as its probability. Cell allocation is spreaded, not linear." // Place the rest in the table const u16 step = (size >> 1) + (size >> 3) + 3; const u16 mask = size - 1; u16 pos = 0; for (int s = 0; s < num_symbs; s++) { if (norm_freqs[s] <= 0) { continue; } state_desc[s] = norm_freqs[s]; for (int i = 0; i < norm_freqs[s]; i++) { // Give `norm_freqs[s]` states to symbol s dtable->symbols[pos] = s; // "A position is skipped if already occupied, typically by a "less // than 1" probability symbol." do { pos = (pos + step) & mask; } while (pos >= high_threshold); // Note: no other collision checking is necessary as `step` is // coprime to `size`, so the cycle will visit each position exactly // once } } if (pos != 0) { CORRUPTION(); } // Now we can fill baseline and num bits for (size_t i = 0; i < size; i++) { u8 symbol = dtable->symbols[i]; u16 next_state_desc = state_desc[symbol]++; // Fills in the table appropriately, next_state_desc increases by symbol // over time, decreasing number of bits dtable->num_bits[i] = (u8)(accuracy_log - highest_set_bit(next_state_desc)); // Baseline increases until the bit threshold is passed, at which point // it resets to 0 dtable->new_state_base[i] = ((u16)next_state_desc << dtable->num_bits[i]) - size; } } /// Decode an FSE header as defined in the Zstandard format specification and /// use the decoded frequencies to initialize a decoding table. static void FSE_decode_header(FSE_dtable *const dtable, istream_t *const in, const int max_accuracy_log) { // "An FSE distribution table describes the probabilities of all symbols // from 0 to the last present one (included) on a normalized scale of 1 << // Accuracy_Log . // // It's a bitstream which is read forward, in little-endian fashion. It's // not necessary to know its exact size, since it will be discovered and // reported by the decoding process. if (max_accuracy_log > FSE_MAX_ACCURACY_LOG) { ERROR("FSE accuracy too large"); } // The bitstream starts by reporting on which scale it operates. // Accuracy_Log = low4bits + 5. Note that maximum Accuracy_Log for literal // and match lengths is 9, and for offsets is 8. Higher values are // considered errors." const int accuracy_log = 5 + IO_read_bits(in, 4); if (accuracy_log > max_accuracy_log) { ERROR("FSE accuracy too large"); } // "Then follows each symbol value, from 0 to last present one. The number // of bits used by each field is variable. It depends on : // // Remaining probabilities + 1 : example : Presuming an Accuracy_Log of 8, // and presuming 100 probabilities points have already been distributed, the // decoder may read any value from 0 to 255 - 100 + 1 == 156 (inclusive). // Therefore, it must read log2sup(156) == 8 bits. // // Value decoded : small values use 1 less bit : example : Presuming values // from 0 to 156 (inclusive) are possible, 255-156 = 99 values are remaining // in an 8-bits field. They are used this way : first 99 values (hence from // 0 to 98) use only 7 bits, values from 99 to 156 use 8 bits. " i32 remaining = 1 << accuracy_log; i16 frequencies[FSE_MAX_SYMBS]; int symb = 0; while (remaining > 0 && symb < FSE_MAX_SYMBS) { // Log of the number of possible values we could read int bits = highest_set_bit(remaining + 1) + 1; u16 val = IO_read_bits(in, bits); // Try to mask out the lower bits to see if it qualifies for the "small // value" threshold const u16 lower_mask = ((u16)1 << (bits - 1)) - 1; const u16 threshold = ((u16)1 << bits) - 1 - (remaining + 1); if ((val & lower_mask) < threshold) { IO_rewind_bits(in, 1); val = val & lower_mask; } else if (val > lower_mask) { val = val - threshold; } // "Probability is obtained from Value decoded by following formula : // Proba = value - 1" const i16 proba = (i16)val - 1; // "It means value 0 becomes negative probability -1. -1 is a special // probability, which means "less than 1". Its effect on distribution // table is described in next paragraph. For the purpose of calculating // cumulated distribution, it counts as one." remaining -= proba < 0 ? -proba : proba; frequencies[symb] = proba; symb++; // "When a symbol has a probability of zero, it is followed by a 2-bits // repeat flag. This repeat flag tells how many probabilities of zeroes // follow the current one. It provides a number ranging from 0 to 3. If // it is a 3, another 2-bits repeat flag follows, and so on." if (proba == 0) { // Read the next two bits to see how many more 0s int repeat = IO_read_bits(in, 2); while (1) { for (int i = 0; i < repeat && symb < FSE_MAX_SYMBS; i++) { frequencies[symb++] = 0; } if (repeat == 3) { repeat = IO_read_bits(in, 2); } else { break; } } } } IO_align_stream(in); // "When last symbol reaches cumulated total of 1 << Accuracy_Log, decoding // is complete. If the last symbol makes cumulated total go above 1 << // Accuracy_Log, distribution is considered corrupted." if (remaining != 0 || symb >= FSE_MAX_SYMBS) { CORRUPTION(); } // Initialize the decoding table using the determined weights FSE_init_dtable(dtable, frequencies, symb, accuracy_log); } static void FSE_init_dtable_rle(FSE_dtable *const dtable, const u8 symb) { dtable->symbols = malloc(sizeof(u8)); dtable->num_bits = malloc(sizeof(u8)); dtable->new_state_base = malloc(sizeof(u16)); if (!dtable->symbols || !dtable->num_bits || !dtable->new_state_base) { BAD_ALLOC(); } // This setup will always have a state of 0, always return symbol `symb`, // and never consume any bits dtable->symbols[0] = symb; dtable->num_bits[0] = 0; dtable->new_state_base[0] = 0; dtable->accuracy_log = 0; } static void FSE_free_dtable(FSE_dtable *const dtable) { free(dtable->symbols); free(dtable->num_bits); free(dtable->new_state_base); memset(dtable, 0, sizeof(FSE_dtable)); } static void FSE_copy_dtable(FSE_dtable *const dst, const FSE_dtable *const src) { if (src->accuracy_log == 0) { memset(dst, 0, sizeof(FSE_dtable)); return; } size_t size = (size_t)1 << src->accuracy_log; dst->accuracy_log = src->accuracy_log; dst->symbols = malloc(size); dst->num_bits = malloc(size); dst->new_state_base = malloc(size * sizeof(u16)); if (!dst->symbols || !dst->num_bits || !dst->new_state_base) { BAD_ALLOC(); } memcpy(dst->symbols, src->symbols, size); memcpy(dst->num_bits, src->num_bits, size); memcpy(dst->new_state_base, src->new_state_base, size * sizeof(u16)); } /******* END FSE PRIMITIVES ***************************************************/ Index: head/sys/contrib/zstd/doc/educational_decoder/zstd_decompress.h =================================================================== --- head/sys/contrib/zstd/doc/educational_decoder/zstd_decompress.h (revision 354776) +++ head/sys/contrib/zstd/doc/educational_decoder/zstd_decompress.h (revision 354777) @@ -1,58 +1,60 @@ /* * Copyright (c) 2016-present, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). */ +#include /* size_t */ + /******* EXPOSED TYPES ********************************************************/ /* * Contains the parsed contents of a dictionary * This includes Huffman and FSE tables used for decoding and data on offsets */ typedef struct dictionary_s dictionary_t; /******* END EXPOSED TYPES ****************************************************/ /******* DECOMPRESSION FUNCTIONS **********************************************/ /// Zstandard decompression functions. /// `dst` must point to a space at least as large as the reconstructed output. size_t ZSTD_decompress(void *const dst, const size_t dst_len, const void *const src, const size_t src_len); /// If `dict != NULL` and `dict_len >= 8`, does the same thing as /// `ZSTD_decompress` but uses the provided dict size_t ZSTD_decompress_with_dict(void *const dst, const size_t dst_len, const void *const src, const size_t src_len, dictionary_t* parsed_dict); /// Get the decompressed size of an input stream so memory can be allocated in /// advance /// Returns -1 if the size can't be determined /// Assumes decompression of a single frame size_t ZSTD_get_decompressed_size(const void *const src, const size_t src_len); /******* END DECOMPRESSION FUNCTIONS ******************************************/ /******* DICTIONARY MANAGEMENT ***********************************************/ /* * Return a valid dictionary_t pointer for use with dictionary initialization * or decompression */ -dictionary_t* create_dictionary(); +dictionary_t* create_dictionary(void); /* * Parse a provided dictionary blob for use in decompression * `src` -- must point to memory space representing the dictionary * `src_len` -- must provide the dictionary size * `dict` -- will contain the parsed contents of the dictionary and * can be used for decompression */ void parse_dictionary(dictionary_t *const dict, const void *src, size_t src_len); /* * Free internal Huffman tables, FSE tables, and dictionary content */ void free_dictionary(dictionary_t *const dict); /******* END DICTIONARY MANAGEMENT *******************************************/ Index: head/sys/contrib/zstd/doc/zstd_compression_format.md =================================================================== --- head/sys/contrib/zstd/doc/zstd_compression_format.md (revision 354776) +++ head/sys/contrib/zstd/doc/zstd_compression_format.md (revision 354777) @@ -1,1671 +1,1678 @@ Zstandard Compression Format ============================ ### Notices Copyright (c) 2016-present Yann Collet, Facebook, Inc. Permission is granted to copy and distribute this document for any purpose and without charge, including translations into other languages and incorporation into compilations, provided that the copyright notice and this notice are preserved, and that any substantive changes or deletions from the original are clearly marked. Distribution of this document is unlimited. ### Version -0.3.2 (17/07/19) +0.3.4 (16/08/19) Introduction ------------ The purpose of this document is to define a lossless compressed data format, that is independent of CPU type, operating system, file system and character set, suitable for file compression, pipe and streaming compression, using the [Zstandard algorithm](http://www.zstandard.org). The text of the specification assumes a basic background in programming at the level of bits and other primitive data representations. The data can be produced or consumed, even for an arbitrarily long sequentially presented input data stream, using only an a priori bounded amount of intermediate storage, and hence can be used in data communications. The format uses the Zstandard compression method, and optional [xxHash-64 checksum method](http://www.xxhash.org), for detection of data corruption. The data format defined by this specification does not attempt to allow random access to compressed data. Unless otherwise indicated below, a compliant compressor must produce data sets that conform to the specifications presented here. It doesn’t need to support all options though. A compliant decompressor must be able to decompress at least one working set of parameters that conforms to the specifications presented here. It may also ignore informative fields, such as checksum. Whenever it does not support a parameter defined in the compressed stream, it must produce a non-ambiguous error code and associated error message explaining which parameter is unsupported. This specification is intended for use by implementers of software to compress data into Zstandard format and/or decompress data from Zstandard format. The Zstandard format is supported by an open source reference implementation, written in portable C, and available at : https://github.com/facebook/zstd . ### Overall conventions In this document: - square brackets i.e. `[` and `]` are used to indicate optional fields or parameters. - the naming convention for identifiers is `Mixed_Case_With_Underscores` ### Definitions Content compressed by Zstandard is transformed into a Zstandard __frame__. Multiple frames can be appended into a single file or stream. A frame is completely independent, has a defined beginning and end, and a set of parameters which tells the decoder how to decompress it. A frame encapsulates one or multiple __blocks__. Each block contains arbitrary content, which is described by its header, and has a guaranteed maximum content size, which depends on frame parameters. Unlike frames, each block depends on previous blocks for proper decoding. However, each block can be decompressed without waiting for its successor, allowing streaming operations. Overview --------- - [Frames](#frames) - [Zstandard frames](#zstandard-frames) - [Blocks](#blocks) - [Literals Section](#literals-section) - [Sequences Section](#sequences-section) - [Sequence Execution](#sequence-execution) - [Skippable frames](#skippable-frames) - [Entropy Encoding](#entropy-encoding) - [FSE](#fse) - [Huffman Coding](#huffman-coding) - [Dictionary Format](#dictionary-format) Frames ------ Zstandard compressed data is made of one or more __frames__. Each frame is independent and can be decompressed independently of other frames. The decompressed content of multiple concatenated frames is the concatenation of each frame decompressed content. There are two frame formats defined by Zstandard: Zstandard frames and Skippable frames. Zstandard frames contain compressed data, while skippable frames contain custom user metadata. ## Zstandard frames The structure of a single Zstandard frame is following: | `Magic_Number` | `Frame_Header` |`Data_Block`| [More data blocks] | [`Content_Checksum`] | |:--------------:|:--------------:|:----------:| ------------------ |:--------------------:| | 4 bytes | 2-14 bytes | n bytes | | 0-4 bytes | __`Magic_Number`__ 4 Bytes, __little-endian__ format. Value : 0xFD2FB528 Note: This value was selected to be less probable to find at the beginning of some random file. It avoids trivial patterns (0x00, 0xFF, repeated bytes, increasing bytes, etc.), contains byte values outside of ASCII range, and doesn't map into UTF8 space. It reduces the chances that a text file represent this value by accident. __`Frame_Header`__ 2 to 14 Bytes, detailed in [`Frame_Header`](#frame_header). __`Data_Block`__ Detailed in [`Blocks`](#blocks). That’s where compressed data is stored. __`Content_Checksum`__ An optional 32-bit checksum, only present if `Content_Checksum_flag` is set. The content checksum is the result of [xxh64() hash function](http://www.xxhash.org) digesting the original (decoded) data as input, and a seed of zero. The low 4 bytes of the checksum are stored in __little-endian__ format. ### `Frame_Header` The `Frame_Header` has a variable size, with a minimum of 2 bytes, and up to 14 bytes depending on optional parameters. The structure of `Frame_Header` is following: | `Frame_Header_Descriptor` | [`Window_Descriptor`] | [`Dictionary_ID`] | [`Frame_Content_Size`] | | ------------------------- | --------------------- | ----------------- | ---------------------- | | 1 byte | 0-1 byte | 0-4 bytes | 0-8 bytes | #### `Frame_Header_Descriptor` The first header's byte is called the `Frame_Header_Descriptor`. It describes which other fields are present. Decoding this byte is enough to tell the size of `Frame_Header`. | Bit number | Field name | | ---------- | ---------- | | 7-6 | `Frame_Content_Size_flag` | | 5 | `Single_Segment_flag` | | 4 | `Unused_bit` | | 3 | `Reserved_bit` | | 2 | `Content_Checksum_flag` | | 1-0 | `Dictionary_ID_flag` | In this table, bit 7 is the highest bit, while bit 0 is the lowest one. __`Frame_Content_Size_flag`__ This is a 2-bits flag (`= Frame_Header_Descriptor >> 6`), specifying if `Frame_Content_Size` (the decompressed data size) is provided within the header. `Flag_Value` provides `FCS_Field_Size`, which is the number of bytes used by `Frame_Content_Size` according to the following table: | `Flag_Value` | 0 | 1 | 2 | 3 | | -------------- | ------ | --- | --- | --- | |`FCS_Field_Size`| 0 or 1 | 2 | 4 | 8 | When `Flag_Value` is `0`, `FCS_Field_Size` depends on `Single_Segment_flag` : if `Single_Segment_flag` is set, `FCS_Field_Size` is 1. Otherwise, `FCS_Field_Size` is 0 : `Frame_Content_Size` is not provided. __`Single_Segment_flag`__ If this flag is set, data must be regenerated within a single continuous memory segment. In this case, `Window_Descriptor` byte is skipped, but `Frame_Content_Size` is necessarily present. As a consequence, the decoder must allocate a memory segment of size equal or larger than `Frame_Content_Size`. In order to preserve the decoder from unreasonable memory requirements, a decoder is allowed to reject a compressed frame which requests a memory size beyond decoder's authorized range. For broader compatibility, decoders are recommended to support memory sizes of at least 8 MB. This is only a recommendation, each decoder is free to support higher or lower limits, depending on local limitations. __`Unused_bit`__ A decoder compliant with this specification version shall not interpret this bit. It might be used in any future version, to signal a property which is transparent to properly decode the frame. An encoder compliant with this specification version must set this bit to zero. __`Reserved_bit`__ This bit is reserved for some future feature. Its value _must be zero_. A decoder compliant with this specification version must ensure it is not set. This bit may be used in a future revision, to signal a feature that must be interpreted to decode the frame correctly. __`Content_Checksum_flag`__ If this flag is set, a 32-bits `Content_Checksum` will be present at frame's end. See `Content_Checksum` paragraph. __`Dictionary_ID_flag`__ This is a 2-bits flag (`= FHD & 3`), telling if a dictionary ID is provided within the header. It also specifies the size of this field as `DID_Field_Size`. |`Flag_Value` | 0 | 1 | 2 | 3 | | -------------- | --- | --- | --- | --- | |`DID_Field_Size`| 0 | 1 | 2 | 4 | #### `Window_Descriptor` Provides guarantees on minimum memory buffer required to decompress a frame. This information is important for decoders to allocate enough memory. The `Window_Descriptor` byte is optional. When `Single_Segment_flag` is set, `Window_Descriptor` is not present. In this case, `Window_Size` is `Frame_Content_Size`, which can be any value from 0 to 2^64-1 bytes (16 ExaBytes). | Bit numbers | 7-3 | 2-0 | | ----------- | ---------- | ---------- | | Field name | `Exponent` | `Mantissa` | The minimum memory buffer size is called `Window_Size`. It is described by the following formulas : ``` windowLog = 10 + Exponent; windowBase = 1 << windowLog; windowAdd = (windowBase / 8) * Mantissa; Window_Size = windowBase + windowAdd; ``` The minimum `Window_Size` is 1 KB. The maximum `Window_Size` is `(1<<41) + 7*(1<<38)` bytes, which is 3.75 TB. In general, larger `Window_Size` tend to improve compression ratio, but at the cost of memory usage. To properly decode compressed data, a decoder will need to allocate a buffer of at least `Window_Size` bytes. In order to preserve decoder from unreasonable memory requirements, a decoder is allowed to reject a compressed frame which requests a memory size beyond decoder's authorized range. For improved interoperability, it's recommended for decoders to support `Window_Size` of up to 8 MB, and it's recommended for encoders to not generate frame requiring `Window_Size` larger than 8 MB. It's merely a recommendation though, decoders are free to support larger or lower limits, depending on local limitations. #### `Dictionary_ID` This is a variable size field, which contains the ID of the dictionary required to properly decode the frame. `Dictionary_ID` field is optional. When it's not present, it's up to the decoder to know which dictionary to use. `Dictionary_ID` field size is provided by `DID_Field_Size`. `DID_Field_Size` is directly derived from value of `Dictionary_ID_flag`. 1 byte can represent an ID 0-255. 2 bytes can represent an ID 0-65535. 4 bytes can represent an ID 0-4294967295. Format is __little-endian__. It's allowed to represent a small ID (for example `13`) with a large 4-bytes dictionary ID, even if it is less efficient. _Reserved ranges :_ Within private environments, any `Dictionary_ID` can be used. However, for frames and dictionaries distributed in public space, `Dictionary_ID` must be attributed carefully. Rules for public environment are not yet decided, but the following ranges are reserved for some future registrar : - low range : `<= 32767` - high range : `>= (1 << 31)` Outside of these ranges, any value of `Dictionary_ID` which is both `>= 32768` and `< (1<<31)` can be used freely, even in public environment. #### `Frame_Content_Size` This is the original (uncompressed) size. This information is optional. `Frame_Content_Size` uses a variable number of bytes, provided by `FCS_Field_Size`. `FCS_Field_Size` is provided by the value of `Frame_Content_Size_flag`. `FCS_Field_Size` can be equal to 0 (not present), 1, 2, 4 or 8 bytes. | `FCS_Field_Size` | Range | | ---------------- | ---------- | | 0 | unknown | | 1 | 0 - 255 | | 2 | 256 - 65791| | 4 | 0 - 2^32-1 | | 8 | 0 - 2^64-1 | `Frame_Content_Size` format is __little-endian__. When `FCS_Field_Size` is 1, 4 or 8 bytes, the value is read directly. When `FCS_Field_Size` is 2, _the offset of 256 is added_. It's allowed to represent a small size (for example `18`) using any compatible variant. Blocks ------- After `Magic_Number` and `Frame_Header`, there are some number of blocks. Each frame must have at least one block, but there is no upper limit on the number of blocks per frame. The structure of a block is as follows: | `Block_Header` | `Block_Content` | |:--------------:|:---------------:| | 3 bytes | n bytes | `Block_Header` uses 3 bytes, written using __little-endian__ convention. It contains 3 fields : | `Last_Block` | `Block_Type` | `Block_Size` | |:------------:|:------------:|:------------:| | bit 0 | bits 1-2 | bits 3-23 | __`Last_Block`__ The lowest bit signals if this block is the last one. The frame will end after this last block. It may be followed by an optional `Content_Checksum` (see [Zstandard Frames](#zstandard-frames)). __`Block_Type`__ The next 2 bits represent the `Block_Type`. +`Block_Type` influences the meaning of `Block_Size`. There are 4 block types : | Value | 0 | 1 | 2 | 3 | | ------------ | ----------- | ----------- | ------------------ | --------- | | `Block_Type` | `Raw_Block` | `RLE_Block` | `Compressed_Block` | `Reserved`| - `Raw_Block` - this is an uncompressed block. `Block_Content` contains `Block_Size` bytes. - `RLE_Block` - this is a single byte, repeated `Block_Size` times. `Block_Content` consists of a single byte. On the decompression side, this byte must be repeated `Block_Size` times. - `Compressed_Block` - this is a [Zstandard compressed block](#compressed-blocks), explained later on. `Block_Size` is the length of `Block_Content`, the compressed data. The decompressed size is not known, but its maximum possible value is guaranteed (see below) - `Reserved` - this is not a block. This value cannot be used with current version of this specification. If such a value is present, it is considered corrupted data. __`Block_Size`__ The upper 21 bits of `Block_Header` represent the `Block_Size`. -`Block_Size` is the size of the block excluding the header. -A block can contain any number of bytes (even zero), up to -`Block_Maximum_Decompressed_Size`, which is the smallest of: +When `Block_Type` is `Compressed_Block` or `Raw_Block`, +`Block_Size` is the size of `Block_Content`, hence excluding `Block_Header`. +When `Block_Type` is `RLE_Block`, `Block_Content`’s size is always 1, +and `Block_Size` represents the number of times this byte must be repeated. +A block can contain and decompress into any number of bytes (even zero), +up to `Block_Maximum_Decompressed_Size`, which is the smallest of: - Window_Size - 128 KB If this condition cannot be respected when generating a `Compressed_Block`, the block must be sent uncompressed instead (`Raw_Block`). Compressed Blocks ----------------- To decompress a compressed block, the compressed size must be provided from `Block_Size` field within `Block_Header`. A compressed block consists of 2 sections : - [Literals Section](#literals-section) - [Sequences Section](#sequences-section) The results of the two sections are then combined to produce the decompressed data in [Sequence Execution](#sequence-execution) #### Prerequisites To decode a compressed block, the following elements are necessary : - Previous decoded data, up to a distance of `Window_Size`, or beginning of the Frame, whichever is smaller. - List of "recent offsets" from previous `Compressed_Block`. - The previous Huffman tree, required by `Treeless_Literals_Block` type - Previous FSE decoding tables, required by `Repeat_Mode` for each symbol type (literals lengths, match lengths, offsets) Note that decoding tables aren't always from the previous `Compressed_Block`. - Every decoding table can come from a dictionary. - The Huffman tree comes from the previous `Compressed_Literals_Block`. Literals Section ---------------- All literals are regrouped in the first part of the block. They can be decoded first, and then copied during [Sequence Execution], or they can be decoded on the flow during [Sequence Execution]. Literals can be stored uncompressed or compressed using Huffman prefix codes. When compressed, an optional tree description can be present, followed by 1 or 4 streams. | `Literals_Section_Header` | [`Huffman_Tree_Description`] | [jumpTable] | Stream1 | [Stream2] | [Stream3] | [Stream4] | | ------------------------- | ---------------------------- | ----------- | ------- | --------- | --------- | --------- | ### `Literals_Section_Header` Header is in charge of describing how literals are packed. It's a byte-aligned variable-size bitfield, ranging from 1 to 5 bytes, using __little-endian__ convention. | `Literals_Block_Type` | `Size_Format` | `Regenerated_Size` | [`Compressed_Size`] | | --------------------- | ------------- | ------------------ | ------------------- | | 2 bits | 1 - 2 bits | 5 - 20 bits | 0 - 18 bits | In this representation, bits on the left are the lowest bits. __`Literals_Block_Type`__ This field uses 2 lowest bits of first byte, describing 4 different block types : | `Literals_Block_Type` | Value | | --------------------------- | ----- | | `Raw_Literals_Block` | 0 | | `RLE_Literals_Block` | 1 | | `Compressed_Literals_Block` | 2 | | `Treeless_Literals_Block` | 3 | - `Raw_Literals_Block` - Literals are stored uncompressed. - `RLE_Literals_Block` - Literals consist of a single byte value repeated `Regenerated_Size` times. - `Compressed_Literals_Block` - This is a standard Huffman-compressed block, starting with a Huffman tree description. See details below. - `Treeless_Literals_Block` - This is a Huffman-compressed block, using Huffman tree _from previous Huffman-compressed literals block_. `Huffman_Tree_Description` will be skipped. Note: If this mode is triggered without any previous Huffman-table in the frame (or [dictionary](#dictionary-format)), this should be treated as data corruption. __`Size_Format`__ `Size_Format` is divided into 2 families : - For `Raw_Literals_Block` and `RLE_Literals_Block`, it's only necessary to decode `Regenerated_Size`. There is no `Compressed_Size` field. - For `Compressed_Block` and `Treeless_Literals_Block`, it's required to decode both `Compressed_Size` and `Regenerated_Size` (the decompressed size). It's also necessary to decode the number of streams (1 or 4). For values spanning several bytes, convention is __little-endian__. __`Size_Format` for `Raw_Literals_Block` and `RLE_Literals_Block`__ : `Size_Format` uses 1 _or_ 2 bits. Its value is : `Size_Format = (Literals_Section_Header[0]>>2) & 3` - `Size_Format` == 00 or 10 : `Size_Format` uses 1 bit. `Regenerated_Size` uses 5 bits (0-31). `Literals_Section_Header` uses 1 byte. `Regenerated_Size = Literals_Section_Header[0]>>3` - `Size_Format` == 01 : `Size_Format` uses 2 bits. `Regenerated_Size` uses 12 bits (0-4095). `Literals_Section_Header` uses 2 bytes. `Regenerated_Size = (Literals_Section_Header[0]>>4) + (Literals_Section_Header[1]<<4)` - `Size_Format` == 11 : `Size_Format` uses 2 bits. `Regenerated_Size` uses 20 bits (0-1048575). `Literals_Section_Header` uses 3 bytes. `Regenerated_Size = (Literals_Section_Header[0]>>4) + (Literals_Section_Header[1]<<4) + (Literals_Section_Header[2]<<12)` Only Stream1 is present for these cases. Note : it's allowed to represent a short value (for example `13`) using a long format, even if it's less efficient. __`Size_Format` for `Compressed_Literals_Block` and `Treeless_Literals_Block`__ : `Size_Format` always uses 2 bits. - `Size_Format` == 00 : _A single stream_. Both `Regenerated_Size` and `Compressed_Size` use 10 bits (0-1023). `Literals_Section_Header` uses 3 bytes. - `Size_Format` == 01 : 4 streams. Both `Regenerated_Size` and `Compressed_Size` use 10 bits (0-1023). `Literals_Section_Header` uses 3 bytes. - `Size_Format` == 10 : 4 streams. Both `Regenerated_Size` and `Compressed_Size` use 14 bits (0-16383). `Literals_Section_Header` uses 4 bytes. - `Size_Format` == 11 : 4 streams. Both `Regenerated_Size` and `Compressed_Size` use 18 bits (0-262143). `Literals_Section_Header` uses 5 bytes. Both `Compressed_Size` and `Regenerated_Size` fields follow __little-endian__ convention. Note: `Compressed_Size` __includes__ the size of the Huffman Tree description _when_ it is present. #### Raw Literals Block The data in Stream1 is `Regenerated_Size` bytes long, it contains the raw literals data to be used during [Sequence Execution]. #### RLE Literals Block Stream1 consists of a single byte which should be repeated `Regenerated_Size` times to generate the decoded literals. #### Compressed Literals Block and Treeless Literals Block Both of these modes contain Huffman encoded data. For `Treeless_Literals_Block`, the Huffman table comes from previously compressed literals block, or from a dictionary. ### `Huffman_Tree_Description` This section is only present when `Literals_Block_Type` type is `Compressed_Literals_Block` (`2`). The format of the Huffman tree description can be found at [Huffman Tree description](#huffman-tree-description). The size of `Huffman_Tree_Description` is determined during decoding process, it must be used to determine where streams begin. `Total_Streams_Size = Compressed_Size - Huffman_Tree_Description_Size`. ### Jump Table The Jump Table is only present when there are 4 Huffman-coded streams. Reminder : Huffman compressed data consists of either 1 or 4 Huffman-coded streams. If only one stream is present, it is a single bitstream occupying the entire remaining portion of the literals block, encoded as described within [Huffman-Coded Streams](#huffman-coded-streams). If there are four streams, `Literals_Section_Header` only provided enough information to know the decompressed and compressed sizes of all four streams _combined_. The decompressed size of _each_ stream is equal to `(Regenerated_Size+3)/4`, except for the last stream which may be up to 3 bytes smaller, to reach a total decompressed size as specified in `Regenerated_Size`. The compressed size of each stream is provided explicitly in the Jump Table. Jump Table is 6 bytes long, and consist of three 2-byte __little-endian__ fields, describing the compressed sizes of the first three streams. `Stream4_Size` is computed from total `Total_Streams_Size` minus sizes of other streams. `Stream4_Size = Total_Streams_Size - 6 - Stream1_Size - Stream2_Size - Stream3_Size`. Note: if `Stream1_Size + Stream2_Size + Stream3_Size > Total_Streams_Size`, data is considered corrupted. Each of these 4 bitstreams is then decoded independently as a Huffman-Coded stream, as described at [Huffman-Coded Streams](#huffman-coded-streams) Sequences Section ----------------- A compressed block is a succession of _sequences_ . A sequence is a literal copy command, followed by a match copy command. A literal copy command specifies a length. It is the number of bytes to be copied (or extracted) from the Literals Section. A match copy command specifies an offset and a length. When all _sequences_ are decoded, if there are literals left in the _literals section_, these bytes are added at the end of the block. This is described in more detail in [Sequence Execution](#sequence-execution). The `Sequences_Section` regroup all symbols required to decode commands. There are 3 symbol types : literals lengths, offsets and match lengths. They are encoded together, interleaved, in a single _bitstream_. The `Sequences_Section` starts by a header, followed by optional probability tables for each symbol type, followed by the bitstream. | `Sequences_Section_Header` | [`Literals_Length_Table`] | [`Offset_Table`] | [`Match_Length_Table`] | bitStream | | -------------------------- | ------------------------- | ---------------- | ---------------------- | --------- | To decode the `Sequences_Section`, it's required to know its size. Its size is deduced from the size of `Literals_Section`: `Sequences_Section_Size = Block_Size - Literals_Section_Size`. #### `Sequences_Section_Header` Consists of 2 items: - `Number_of_Sequences` - Symbol compression modes __`Number_of_Sequences`__ This is a variable size field using between 1 and 3 bytes. Let's call its first byte `byte0`. - `if (byte0 == 0)` : there are no sequences. The sequence section stops there. Decompressed content is defined entirely as Literals Section content. The FSE tables used in `Repeat_Mode` aren't updated. - `if (byte0 < 128)` : `Number_of_Sequences = byte0` . Uses 1 byte. - `if (byte0 < 255)` : `Number_of_Sequences = ((byte0-128) << 8) + byte1` . Uses 2 bytes. - `if (byte0 == 255)`: `Number_of_Sequences = byte1 + (byte2<<8) + 0x7F00` . Uses 3 bytes. __Symbol compression modes__ This is a single byte, defining the compression mode of each symbol type. |Bit number| 7-6 | 5-4 | 3-2 | 1-0 | | -------- | ----------------------- | -------------- | -------------------- | ---------- | |Field name| `Literals_Lengths_Mode` | `Offsets_Mode` | `Match_Lengths_Mode` | `Reserved` | The last field, `Reserved`, must be all-zeroes. `Literals_Lengths_Mode`, `Offsets_Mode` and `Match_Lengths_Mode` define the `Compression_Mode` of literals lengths, offsets, and match lengths symbols respectively. They follow the same enumeration : | Value | 0 | 1 | 2 | 3 | | ------------------ | ----------------- | ---------- | --------------------- | ------------- | | `Compression_Mode` | `Predefined_Mode` | `RLE_Mode` | `FSE_Compressed_Mode` | `Repeat_Mode` | - `Predefined_Mode` : A predefined FSE distribution table is used, defined in [default distributions](#default-distributions). No distribution table will be present. - `RLE_Mode` : The table description consists of a single byte, which contains the symbol's value. This symbol will be used for all sequences. - `FSE_Compressed_Mode` : standard FSE compression. A distribution table will be present. The format of this distribution table is described in [FSE Table Description](#fse-table-description). Note that the maximum allowed accuracy log for literals length and match length tables is 9, and the maximum accuracy log for the offsets table is 8. `FSE_Compressed_Mode` must not be used when only one symbol is present, `RLE_Mode` should be used instead (although any other mode will work). - `Repeat_Mode` : The table used in the previous `Compressed_Block` with `Number_of_Sequences > 0` will be used again, or if this is the first block, table in the dictionary will be used. Note that this includes `RLE_mode`, so if `Repeat_Mode` follows `RLE_Mode`, the same symbol will be repeated. It also includes `Predefined_Mode`, in which case `Repeat_Mode` will have same outcome as `Predefined_Mode`. No distribution table will be present. If this mode is used without any previous sequence table in the frame (nor [dictionary](#dictionary-format)) to repeat, this should be treated as corruption. #### The codes for literals lengths, match lengths, and offsets. Each symbol is a _code_ in its own context, which specifies `Baseline` and `Number_of_Bits` to add. _Codes_ are FSE compressed, and interleaved with raw additional bits in the same bitstream. ##### Literals length codes Literals length codes are values ranging from `0` to `35` included. They define lengths from 0 to 131071 bytes. The literals length is equal to the decoded `Baseline` plus the result of reading `Number_of_Bits` bits from the bitstream, as a __little-endian__ value. | `Literals_Length_Code` | 0-15 | | ---------------------- | ---------------------- | | length | `Literals_Length_Code` | | `Number_of_Bits` | 0 | | `Literals_Length_Code` | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | | ---------------------- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 16 | 18 | 20 | 22 | 24 | 28 | 32 | 40 | | `Number_of_Bits` | 1 | 1 | 1 | 1 | 2 | 2 | 3 | 3 | | `Literals_Length_Code` | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | | ---------------------- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 48 | 64 | 128 | 256 | 512 | 1024 | 2048 | 4096 | | `Number_of_Bits` | 4 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | | `Literals_Length_Code` | 32 | 33 | 34 | 35 | | ---------------------- | ---- | ---- | ---- | ---- | | `Baseline` | 8192 |16384 |32768 |65536 | | `Number_of_Bits` | 13 | 14 | 15 | 16 | ##### Match length codes Match length codes are values ranging from `0` to `52` included. They define lengths from 3 to 131074 bytes. The match length is equal to the decoded `Baseline` plus the result of reading `Number_of_Bits` bits from the bitstream, as a __little-endian__ value. | `Match_Length_Code` | 0-31 | | ------------------- | ----------------------- | | value | `Match_Length_Code` + 3 | | `Number_of_Bits` | 0 | | `Match_Length_Code` | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | | ------------------- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 35 | 37 | 39 | 41 | 43 | 47 | 51 | 59 | | `Number_of_Bits` | 1 | 1 | 1 | 1 | 2 | 2 | 3 | 3 | | `Match_Length_Code` | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | | ------------------- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 67 | 83 | 99 | 131 | 259 | 515 | 1027 | 2051 | | `Number_of_Bits` | 4 | 4 | 5 | 7 | 8 | 9 | 10 | 11 | | `Match_Length_Code` | 48 | 49 | 50 | 51 | 52 | | ------------------- | ---- | ---- | ---- | ---- | ---- | | `Baseline` | 4099 | 8195 |16387 |32771 |65539 | | `Number_of_Bits` | 12 | 13 | 14 | 15 | 16 | ##### Offset codes Offset codes are values ranging from `0` to `N`. A decoder is free to limit its maximum `N` supported. Recommendation is to support at least up to `22`. For information, at the time of this writing. the reference decoder supports a maximum `N` value of `31`. An offset code is also the number of additional bits to read in __little-endian__ fashion, and can be translated into an `Offset_Value` using the following formulas : ``` Offset_Value = (1 << offsetCode) + readNBits(offsetCode); if (Offset_Value > 3) offset = Offset_Value - 3; ``` It means that maximum `Offset_Value` is `(2^(N+1))-1` supporting back-reference distances up to `(2^(N+1))-4`, but is limited by [maximum back-reference distance](#window_descriptor). `Offset_Value` from 1 to 3 are special : they define "repeat codes". This is described in more detail in [Repeat Offsets](#repeat-offsets). #### Decoding Sequences FSE bitstreams are read in reverse direction than written. In zstd, the compressor writes bits forward into a block and the decompressor must read the bitstream _backwards_. To find the start of the bitstream it is therefore necessary to know the offset of the last byte of the block which can be found by counting `Block_Size` bytes after the block header. After writing the last bit containing information, the compressor writes a single `1`-bit and then fills the byte with 0-7 `0` bits of padding. The last byte of the compressed bitstream cannot be `0` for that reason. When decompressing, the last byte containing the padding is the first byte to read. The decompressor needs to skip 0-7 initial `0`-bits and the first `1`-bit it occurs. Afterwards, the useful part of the bitstream begins. FSE decoding requires a 'state' to be carried from symbol to symbol. For more explanation on FSE decoding, see the [FSE section](#fse). For sequence decoding, a separate state keeps track of each literal lengths, offsets, and match lengths symbols. Some FSE primitives are also used. For more details on the operation of these primitives, see the [FSE section](#fse). ##### Starting states The bitstream starts with initial FSE state values, each using the required number of bits in their respective _accuracy_, decoded previously from their normalized distribution. It starts by `Literals_Length_State`, followed by `Offset_State`, and finally `Match_Length_State`. Reminder : always keep in mind that all values are read _backward_, so the 'start' of the bitstream is at the highest position in memory, immediately before the last `1`-bit for padding. After decoding the starting states, a single sequence is decoded `Number_Of_Sequences` times. These sequences are decoded in order from first to last. Since the compressor writes the bitstream in the forward direction, this means the compressor must encode the sequences starting with the last one and ending with the first. ##### Decoding a sequence For each of the symbol types, the FSE state can be used to determine the appropriate code. The code then defines the `Baseline` and `Number_of_Bits` to read for each type. See the [description of the codes] for how to determine these values. [description of the codes]: #the-codes-for-literals-lengths-match-lengths-and-offsets Decoding starts by reading the `Number_of_Bits` required to decode `Offset`. It then does the same for `Match_Length`, and then for `Literals_Length`. This sequence is then used for [sequence execution](#sequence-execution). If it is not the last sequence in the block, the next operation is to update states. Using the rules pre-calculated in the decoding tables, `Literals_Length_State` is updated, followed by `Match_Length_State`, and then `Offset_State`. See the [FSE section](#fse) for details on how to update states from the bitstream. This operation will be repeated `Number_of_Sequences` times. At the end, the bitstream shall be entirely consumed, otherwise the bitstream is considered corrupted. #### Default Distributions If `Predefined_Mode` is selected for a symbol type, its FSE decoding table is generated from a predefined distribution table defined here. For details on how to convert this distribution into a decoding table, see the [FSE section]. [FSE section]: #from-normalized-distribution-to-decoding-tables ##### Literals Length The decoding table uses an accuracy log of 6 bits (64 states). ``` short literalsLength_defaultDistribution[36] = { 4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1, -1,-1,-1,-1 }; ``` ##### Match Length The decoding table uses an accuracy log of 6 bits (64 states). ``` short matchLengths_defaultDistribution[53] = { 1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1, -1,-1,-1,-1,-1 }; ``` ##### Offset Codes The decoding table uses an accuracy log of 5 bits (32 states), and supports a maximum `N` value of 28, allowing offset values up to 536,870,908 . If any sequence in the compressed block requires a larger offset than this, it's not possible to use the default distribution to represent it. ``` short offsetCodes_defaultDistribution[29] = { 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,-1,-1,-1,-1,-1 }; ``` Sequence Execution ------------------ Once literals and sequences have been decoded, they are combined to produce the decoded content of a block. Each sequence consists of a tuple of (`literals_length`, `offset_value`, `match_length`), decoded as described in the [Sequences Section](#sequences-section). To execute a sequence, first copy `literals_length` bytes from the decoded literals to the output. Then `match_length` bytes are copied from previous decoded data. The offset to copy from is determined by `offset_value`: if `offset_value > 3`, then the offset is `offset_value - 3`. If `offset_value` is from 1-3, the offset is a special repeat offset value. See the [repeat offset](#repeat-offsets) section for how the offset is determined in this case. The offset is defined as from the current position, so an offset of 6 and a match length of 3 means that 3 bytes should be copied from 6 bytes back. Note that all offsets leading to previously decoded data must be smaller than `Window_Size` defined in `Frame_Header_Descriptor`. #### Repeat offsets As seen in [Sequence Execution](#sequence-execution), the first 3 values define a repeated offset and we will call them `Repeated_Offset1`, `Repeated_Offset2`, and `Repeated_Offset3`. They are sorted in recency order, with `Repeated_Offset1` meaning "most recent one". If `offset_value == 1`, then the offset used is `Repeated_Offset1`, etc. There is an exception though, when current sequence's `literals_length = 0`. In this case, repeated offsets are shifted by one, so an `offset_value` of 1 means `Repeated_Offset2`, an `offset_value` of 2 means `Repeated_Offset3`, and an `offset_value` of 3 means `Repeated_Offset1 - 1_byte`. For the first block, the starting offset history is populated with following values : `Repeated_Offset1`=1, `Repeated_Offset2`=4, `Repeated_Offset3`=8, unless a dictionary is used, in which case they come from the dictionary. Then each block gets its starting offset history from the ending values of the most recent `Compressed_Block`. Note that blocks which are not `Compressed_Block` are skipped, they do not contribute to offset history. [Offset Codes]: #offset-codes ###### Offset updates rules The newest offset takes the lead in offset history, shifting others back by one rank, up to the previous rank of the new offset _if it was present in history_. __Examples__ : In the common case, when new offset is not part of history : `Repeated_Offset3` = `Repeated_Offset2` `Repeated_Offset2` = `Repeated_Offset1` `Repeated_Offset1` = `NewOffset` When the new offset _is_ part of history, there may be specific adjustments. When `NewOffset` == `Repeated_Offset1`, offset history remains actually unmodified. When `NewOffset` == `Repeated_Offset2`, `Repeated_Offset1` and `Repeated_Offset2` ranks are swapped. `Repeated_Offset3` is unmodified. When `NewOffset` == `Repeated_Offset3`, there is actually no difference with the common case : all offsets are shifted by one rank, `NewOffset` (== `Repeated_Offset3`) becomes the new `Repeated_Offset1`. Also worth mentioning, the specific corner case when `offset_value` == 3, and the literal length of the current sequence is zero. In which case , `NewOffset` = `Repeated_Offset1` - 1_byte. Here also, from an offset history update perspective, it's just a common case : `Repeated_Offset3` = `Repeated_Offset2` `Repeated_Offset2` = `Repeated_Offset1` `Repeated_Offset1` = `NewOffset` ( == `Repeated_Offset1` - 1_byte ) Skippable Frames ---------------- | `Magic_Number` | `Frame_Size` | `User_Data` | |:--------------:|:------------:|:-----------:| | 4 bytes | 4 bytes | n bytes | Skippable frames allow the insertion of user-defined metadata into a flow of concatenated frames. Skippable frames defined in this specification are compatible with [LZ4] ones. [LZ4]:http://www.lz4.org From a compliant decoder perspective, skippable frames need just be skipped, and their content ignored, resuming decoding after the skippable frame. It can be noted that a skippable frame can be used to watermark a stream of concatenated frames embedding any kind of tracking information (even just an UUID). Users wary of such possibility should scan the stream of concatenated frames in an attempt to detect such frame for analysis or removal. __`Magic_Number`__ 4 Bytes, __little-endian__ format. Value : 0x184D2A5?, which means any value from 0x184D2A50 to 0x184D2A5F. All 16 values are valid to identify a skippable frame. This specification doesn't detail any specific tagging for skippable frames. __`Frame_Size`__ This is the size, in bytes, of the following `User_Data` (without including the magic number nor the size field itself). This field is represented using 4 Bytes, __little-endian__ format, unsigned 32-bits. This means `User_Data` can’t be bigger than (2^32-1) bytes. __`User_Data`__ The `User_Data` can be anything. Data will just be skipped by the decoder. Entropy Encoding ---------------- Two types of entropy encoding are used by the Zstandard format: FSE, and Huffman coding. Huffman is used to compress literals, while FSE is used for all other symbols (`Literals_Length_Code`, `Match_Length_Code`, offset codes) and to compress Huffman headers. FSE --- FSE, short for Finite State Entropy, is an entropy codec based on [ANS]. FSE encoding/decoding involves a state that is carried over between symbols, so decoding must be done in the opposite direction as encoding. Therefore, all FSE bitstreams are read from end to beginning. Note that the order of the bits in the stream is not reversed, we just read the elements in the reverse order they are written. For additional details on FSE, see [Finite State Entropy]. [Finite State Entropy]:https://github.com/Cyan4973/FiniteStateEntropy/ FSE decoding involves a decoding table which has a power of 2 size, and contain three elements: `Symbol`, `Num_Bits`, and `Baseline`. The `log2` of the table size is its `Accuracy_Log`. An FSE state value represents an index in this table. To obtain the initial state value, consume `Accuracy_Log` bits from the stream as a __little-endian__ value. The next symbol in the stream is the `Symbol` indicated in the table for that state. To obtain the next state value, the decoder should consume `Num_Bits` bits from the stream as a __little-endian__ value and add it to `Baseline`. [ANS]: https://en.wikipedia.org/wiki/Asymmetric_Numeral_Systems ### FSE Table Description To decode FSE streams, it is necessary to construct the decoding table. The Zstandard format encodes FSE table descriptions as follows: An FSE distribution table describes the probabilities of all symbols from `0` to the last present one (included) on a normalized scale of `1 << Accuracy_Log` . Note that there must be two or more symbols with nonzero probability. It's a bitstream which is read forward, in __little-endian__ fashion. It's not necessary to know bitstream exact size, it will be discovered and reported by the decoding process. The bitstream starts by reporting on which scale it operates. Let's `low4Bits` designate the lowest 4 bits of the first byte : `Accuracy_Log = low4bits + 5`. Then follows each symbol value, from `0` to last present one. The number of bits used by each field is variable. It depends on : - Remaining probabilities + 1 : __example__ : Presuming an `Accuracy_Log` of 8, and presuming 100 probabilities points have already been distributed, the decoder may read any value from `0` to `256 - 100 + 1 == 157` (inclusive). Therefore, it must read `log2sup(157) == 8` bits. - Value decoded : small values use 1 less bit : __example__ : Presuming values from 0 to 157 (inclusive) are possible, 255-157 = 98 values are remaining in an 8-bits field. They are used this way : first 98 values (hence from 0 to 97) use only 7 bits, values from 98 to 157 use 8 bits. This is achieved through this scheme : | Value read | Value decoded | Number of bits used | | ---------- | ------------- | ------------------- | | 0 - 97 | 0 - 97 | 7 | | 98 - 127 | 98 - 127 | 8 | | 128 - 225 | 0 - 97 | 7 | | 226 - 255 | 128 - 157 | 8 | Symbols probabilities are read one by one, in order. Probability is obtained from Value decoded by following formula : `Proba = value - 1` It means value `0` becomes negative probability `-1`. `-1` is a special probability, which means "less than 1". Its effect on distribution table is described in the [next section]. For the purpose of calculating total allocated probability points, it counts as one. [next section]:#from-normalized-distribution-to-decoding-tables When a symbol has a __probability__ of `zero`, it is followed by a 2-bits repeat flag. This repeat flag tells how many probabilities of zeroes follow the current one. It provides a number ranging from 0 to 3. If it is a 3, another 2-bits repeat flag follows, and so on. When last symbol reaches cumulated total of `1 << Accuracy_Log`, decoding is complete. If the last symbol makes cumulated total go above `1 << Accuracy_Log`, distribution is considered corrupted. Then the decoder can tell how many bytes were used in this process, and how many symbols are present. The bitstream consumes a round number of bytes. Any remaining bit within the last byte is just unused. #### From normalized distribution to decoding tables The distribution of normalized probabilities is enough to create a unique decoding table. It follows the following build rule : The table has a size of `Table_Size = 1 << Accuracy_Log`. Each cell describes the symbol decoded, -and instructions to get the next state. +and instructions to get the next state (`Number_of_Bits` and `Baseline`). Symbols are scanned in their natural order for "less than 1" probabilities. Symbols with this probability are being attributed a single cell, starting from the end of the table and retreating. These symbols define a full state reset, reading `Accuracy_Log` bits. -All remaining symbols are allocated in their natural order. -Starting from symbol `0` and table position `0`, +Then, all remaining symbols, sorted in natural order, are allocated cells. +Starting from symbol `0` (if it exists), and table position `0`, each symbol gets allocated as many cells as its probability. Cell allocation is spreaded, not linear : -each successor position follow this rule : +each successor position follows this rule : ``` position += (tableSize>>1) + (tableSize>>3) + 3; position &= tableSize-1; ``` A position is skipped if already occupied by a "less than 1" probability symbol. `position` does not reset between symbols, it simply iterates through each position in the table, switching to the next symbol when enough states have been allocated to the current one. -The result is a list of state values. -Each state will decode the current symbol. +The process guarantees that the table is entirely filled. +Each cell corresponds to a state value, which contains the symbol being decoded. -To get the `Number_of_Bits` and `Baseline` required for next state, -it's first necessary to sort all states in their natural order. -The lower states will need 1 more bit than higher ones. +To add the `Number_of_Bits` and `Baseline` required to retrieve next state, +it's first necessary to sort all occurrences of each symbol in state order. +Lower states will need 1 more bit than higher ones. The process is repeated for each symbol. __Example__ : -Presuming a symbol has a probability of 5. -It receives 5 state values. States are sorted in natural order. +Presuming a symbol has a probability of 5, +it receives 5 cells, corresponding to 5 state values. +These state values are then sorted in natural order. -Next power of 2 is 8. -Space of probabilities is divided into 8 equal parts. -Presuming the `Accuracy_Log` is 7, it defines 128 states. +Next power of 2 after 5 is 8. +Space of probabilities must be divided into 8 equal parts. +Presuming the `Accuracy_Log` is 7, it defines a space of 128 states. Divided by 8, each share is 16 large. -In order to reach 8, 8-5=3 lowest states will count "double", -doubling the number of shares (32 in width), -requiring one more bit in the process. +In order to reach 8 shares, 8-5=3 lowest states will count "double", +doubling their shares (32 in width), hence requiring one more bit. Baseline is assigned starting from the higher states using fewer bits, -and proceeding naturally, then resuming at the first state, -each takes its allocated width from Baseline. +increasing at each state, then resuming at the first state, +each state takes its allocated width from Baseline. -| state order | 0 | 1 | 2 | 3 | 4 | -| ---------------- | ----- | ----- | ------ | ---- | ----- | -| width | 32 | 32 | 32 | 16 | 16 | -| `Number_of_Bits` | 5 | 5 | 5 | 4 | 4 | -| range number | 2 | 4 | 6 | 0 | 1 | -| `Baseline` | 32 | 64 | 96 | 0 | 16 | -| range | 32-63 | 64-95 | 96-127 | 0-15 | 16-31 | +| state value | 1 | 39 | 77 | 84 | 122 | +| state order | 0 | 1 | 2 | 3 | 4 | +| ---------------- | ----- | ----- | ------ | ---- | ------ | +| width | 32 | 32 | 32 | 16 | 16 | +| `Number_of_Bits` | 5 | 5 | 5 | 4 | 4 | +| range number | 2 | 4 | 6 | 0 | 1 | +| `Baseline` | 32 | 64 | 96 | 0 | 16 | +| range | 32-63 | 64-95 | 96-127 | 0-15 | 16-31 | -The next state is determined from current state +During decoding, the next state value is determined from current state value, by reading the required `Number_of_Bits`, and adding the specified `Baseline`. See [Appendix A] for the results of this process applied to the default distributions. [Appendix A]: #appendix-a---decoding-tables-for-predefined-codes Huffman Coding -------------- Zstandard Huffman-coded streams are read backwards, similar to the FSE bitstreams. Therefore, to find the start of the bitstream, it is therefore to know the offset of the last byte of the Huffman-coded stream. After writing the last bit containing information, the compressor writes a single `1`-bit and then fills the byte with 0-7 `0` bits of padding. The last byte of the compressed bitstream cannot be `0` for that reason. When decompressing, the last byte containing the padding is the first byte to read. The decompressor needs to skip 0-7 initial `0`-bits and the first `1`-bit it occurs. Afterwards, the useful part of the bitstream begins. The bitstream contains Huffman-coded symbols in __little-endian__ order, with the codes defined by the method below. ### Huffman Tree Description Prefix coding represents symbols from an a priori known alphabet by bit sequences (codewords), one codeword for each symbol, in a manner such that different symbols may be represented by bit sequences of different lengths, but a parser can always parse an encoded string unambiguously symbol-by-symbol. Given an alphabet with known symbol frequencies, the Huffman algorithm allows the construction of an optimal prefix code using the fewest bits of any possible prefix codes for that alphabet. Prefix code must not exceed a maximum code length. More bits improve accuracy but cost more header size, and require more memory or more complex decoding operations. This specification limits maximum code length to 11 bits. #### Representation All literal values from zero (included) to last present one (excluded) are represented by `Weight` with values from `0` to `Max_Number_of_Bits`. Transformation from `Weight` to `Number_of_Bits` follows this formula : ``` Number_of_Bits = Weight ? (Max_Number_of_Bits + 1 - Weight) : 0 ``` The last symbol's `Weight` is deduced from previously decoded ones, by completing to the nearest power of 2. This power of 2 gives `Max_Number_of_Bits`, the depth of the current tree. `Max_Number_of_Bits` must be <= 11, otherwise the representation is considered corrupted. __Example__ : Let's presume the following Huffman tree must be described : | literal value | 0 | 1 | 2 | 3 | 4 | 5 | | ---------------- | --- | --- | --- | --- | --- | --- | | `Number_of_Bits` | 1 | 2 | 3 | 0 | 4 | 4 | The tree depth is 4, since its longest elements uses 4 bits (longest elements are the one with smallest frequency). Value `5` will not be listed, as it can be determined from values for 0-4, nor will values above `5` as they are all 0. Values from `0` to `4` will be listed using `Weight` instead of `Number_of_Bits`. Weight formula is : ``` Weight = Number_of_Bits ? (Max_Number_of_Bits + 1 - Number_of_Bits) : 0 ``` It gives the following series of weights : | literal value | 0 | 1 | 2 | 3 | 4 | | ------------- | --- | --- | --- | --- | --- | | `Weight` | 4 | 3 | 2 | 0 | 1 | The decoder will do the inverse operation : having collected weights of literal symbols from `0` to `4`, it knows the last literal, `5`, is present with a non-zero `Weight`. The `Weight` of `5` can be determined by advancing to the next power of 2. The sum of `2^(Weight-1)` (excluding 0's) is : `8 + 4 + 2 + 0 + 1 = 15`. Nearest larger power of 2 value is 16. Therefore, `Max_Number_of_Bits = 4` and `Weight[5] = 16-15 = 1`. #### Huffman Tree header This is a single byte value (0-255), which describes how the series of weights is encoded. - if `headerByte` < 128 : the series of weights is compressed using FSE (see below). The length of the FSE-compressed series is equal to `headerByte` (0-127). - if `headerByte` >= 128 : + the series of weights uses a direct representation, where each `Weight` is encoded directly as a 4 bits field (0-15). + They are encoded forward, 2 weights to a byte, first weight taking the top four bits and second one taking the bottom four. * e.g. the following operations could be used to read the weights: `Weight[0] = (Byte[0] >> 4), Weight[1] = (Byte[0] & 0xf)`, etc. + The full representation occupies `Ceiling(Number_of_Weights/2)` bytes, meaning it uses only full bytes even if `Number_of_Weights` is odd. + `Number_of_Weights = headerByte - 127`. * Note that maximum `Number_of_Weights` is 255-127 = 128, therefore, only up to 128 `Weight` can be encoded using direct representation. * Since the last non-zero `Weight` is _not_ encoded, this scheme is compatible with alphabet sizes of up to 129 symbols, hence including literal symbol 128. * If any literal symbol > 128 has a non-zero `Weight`, direct representation is not possible. In such case, it's necessary to use FSE compression. #### Finite State Entropy (FSE) compression of Huffman weights In this case, the series of Huffman weights is compressed using FSE compression. It's a single bitstream with 2 interleaved states, sharing a single distribution table. To decode an FSE bitstream, it is necessary to know its compressed size. Compressed size is provided by `headerByte`. It's also necessary to know its _maximum possible_ decompressed size, which is `255`, since literal values span from `0` to `255`, and last symbol's `Weight` is not represented. An FSE bitstream starts by a header, describing probabilities distribution. It will create a Decoding Table. For a list of Huffman weights, the maximum accuracy log is 6 bits. For more description see the [FSE header description](#fse-table-description) The Huffman header compression uses 2 states, which share the same FSE distribution table. The first state (`State1`) encodes the even indexed symbols, and the second (`State2`) encodes the odd indexed symbols. `State1` is initialized first, and then `State2`, and they take turns decoding a single symbol and updating their state. For more details on these FSE operations, see the [FSE section](#fse). The number of symbols to decode is determined by tracking bitStream overflow condition: If updating state after decoding a symbol would require more bits than remain in the stream, it is assumed that extra bits are 0. Then, symbols for each of the final states are decoded and the process is complete. #### Conversion from weights to Huffman prefix codes All present symbols shall now have a `Weight` value. It is possible to transform weights into `Number_of_Bits`, using this formula: ``` Number_of_Bits = (Weight>0) ? Max_Number_of_Bits + 1 - Weight : 0 ``` Symbols are sorted by `Weight`. Within same `Weight`, symbols keep natural sequential order. Symbols with a `Weight` of zero are removed. Then, starting from lowest `Weight`, prefix codes are distributed in sequential order. __Example__ : Let's presume the following list of weights has been decoded : | Literal | 0 | 1 | 2 | 3 | 4 | 5 | | -------- | --- | --- | --- | --- | --- | --- | | `Weight` | 4 | 3 | 2 | 0 | 1 | 1 | Sorted by weight and then natural sequential order, it gives the following distribution : | Literal | 3 | 4 | 5 | 2 | 1 | 0 | | ---------------- | --- | --- | --- | --- | --- | ---- | | `Weight` | 0 | 1 | 1 | 2 | 3 | 4 | | `Number_of_Bits` | 0 | 4 | 4 | 3 | 2 | 1 | | prefix codes | N/A | 0000| 0001| 001 | 01 | 1 | ### Huffman-coded Streams Given a Huffman decoding table, it's possible to decode a Huffman-coded stream. Each bitstream must be read _backward_, that is starting from the end down to the beginning. Therefore it's necessary to know the size of each bitstream. It's also necessary to know exactly which _bit_ is the last one. This is detected by a final bit flag : the highest bit of latest byte is a final-bit-flag. Consequently, a last byte of `0` is not possible. And the final-bit-flag itself is not part of the useful bitstream. Hence, the last byte contains between 0 and 7 useful bits. Starting from the end, it's possible to read the bitstream in a __little-endian__ fashion, keeping track of already used bits. Since the bitstream is encoded in reverse order, starting from the end read symbols in forward order. For example, if the literal sequence "0145" was encoded using above prefix code, it would be encoded (in reverse order) as: |Symbol | 5 | 4 | 1 | 0 | Padding | |--------|------|------|----|---|---------| |Encoding|`0000`|`0001`|`01`|`1`| `00001` | Resulting in following 2-bytes bitstream : ``` 00010000 00001101 ``` Here is an alternative representation with the symbol codes separated by underscore: ``` 0001_0000 00001_1_01 ``` Reading highest `Max_Number_of_Bits` bits, it's possible to compare extracted value to decoding table, determining the symbol to decode and number of bits to discard. The process continues up to reading the required number of symbols per stream. If a bitstream is not entirely and exactly consumed, hence reaching exactly its beginning position with _all_ bits consumed, the decoding process is considered faulty. Dictionary Format ----------------- Zstandard is compatible with "raw content" dictionaries, free of any format restriction, except that they must be at least 8 bytes. These dictionaries function as if they were just the `Content` part of a formatted dictionary. But dictionaries created by `zstd --train` follow a format, described here. __Pre-requisites__ : a dictionary has a size, defined either by a buffer limit, or a file size. | `Magic_Number` | `Dictionary_ID` | `Entropy_Tables` | `Content` | | -------------- | --------------- | ---------------- | --------- | __`Magic_Number`__ : 4 bytes ID, value 0xEC30A437, __little-endian__ format __`Dictionary_ID`__ : 4 bytes, stored in __little-endian__ format. `Dictionary_ID` can be any value, except 0 (which means no `Dictionary_ID`). It's used by decoders to check if they use the correct dictionary. _Reserved ranges :_ If the frame is going to be distributed in a private environment, any `Dictionary_ID` can be used. However, for public distribution of compressed frames, the following ranges are reserved and shall not be used : - low range : <= 32767 - high range : >= (2^31) __`Entropy_Tables`__ : follow the same format as tables in [compressed blocks]. See the relevant [FSE](#fse-table-description) and [Huffman](#huffman-tree-description) sections for how to decode these tables. They are stored in following order : Huffman tables for literals, FSE table for offsets, FSE table for match lengths, and FSE table for literals lengths. These tables populate the Repeat Stats literals mode and Repeat distribution mode for sequence decoding. It's finally followed by 3 offset values, populating recent offsets (instead of using `{1,4,8}`), stored in order, 4-bytes __little-endian__ each, for a total of 12 bytes. Each recent offset must have a value < dictionary size. __`Content`__ : The rest of the dictionary is its content. The content act as a "past" in front of data to compress or decompress, so it can be referenced in sequence commands. As long as the amount of data decoded from this frame is less than or equal to `Window_Size`, sequence commands may specify offsets longer than the total length of decoded output so far to reference back to the dictionary, even parts of the dictionary with offsets larger than `Window_Size`. After the total output has surpassed `Window_Size` however, this is no longer allowed and the dictionary is no longer accessible. [compressed blocks]: #the-format-of-compressed_block If a dictionary is provided by an external source, it should be loaded with great care, its content considered untrusted. Appendix A - Decoding tables for predefined codes ------------------------------------------------- This appendix contains FSE decoding tables for the predefined literal length, match length, and offset codes. The tables have been constructed using the algorithm as given above in chapter "from normalized distribution to decoding tables". The tables here can be used as examples to crosscheck that an implementation build its decoding tables correctly. #### Literal Length Code: | State | Symbol | Number_Of_Bits | Base | | ----- | ------ | -------------- | ---- | | 0 | 0 | 4 | 0 | | 1 | 0 | 4 | 16 | | 2 | 1 | 5 | 32 | | 3 | 3 | 5 | 0 | | 4 | 4 | 5 | 0 | | 5 | 6 | 5 | 0 | | 6 | 7 | 5 | 0 | | 7 | 9 | 5 | 0 | | 8 | 10 | 5 | 0 | | 9 | 12 | 5 | 0 | | 10 | 14 | 6 | 0 | | 11 | 16 | 5 | 0 | | 12 | 18 | 5 | 0 | | 13 | 19 | 5 | 0 | | 14 | 21 | 5 | 0 | | 15 | 22 | 5 | 0 | | 16 | 24 | 5 | 0 | | 17 | 25 | 5 | 32 | | 18 | 26 | 5 | 0 | | 19 | 27 | 6 | 0 | | 20 | 29 | 6 | 0 | | 21 | 31 | 6 | 0 | | 22 | 0 | 4 | 32 | | 23 | 1 | 4 | 0 | | 24 | 2 | 5 | 0 | | 25 | 4 | 5 | 32 | | 26 | 5 | 5 | 0 | | 27 | 7 | 5 | 32 | | 28 | 8 | 5 | 0 | | 29 | 10 | 5 | 32 | | 30 | 11 | 5 | 0 | | 31 | 13 | 6 | 0 | | 32 | 16 | 5 | 32 | | 33 | 17 | 5 | 0 | | 34 | 19 | 5 | 32 | | 35 | 20 | 5 | 0 | | 36 | 22 | 5 | 32 | | 37 | 23 | 5 | 0 | | 38 | 25 | 4 | 0 | | 39 | 25 | 4 | 16 | | 40 | 26 | 5 | 32 | | 41 | 28 | 6 | 0 | | 42 | 30 | 6 | 0 | | 43 | 0 | 4 | 48 | | 44 | 1 | 4 | 16 | | 45 | 2 | 5 | 32 | | 46 | 3 | 5 | 32 | | 47 | 5 | 5 | 32 | | 48 | 6 | 5 | 32 | | 49 | 8 | 5 | 32 | | 50 | 9 | 5 | 32 | | 51 | 11 | 5 | 32 | | 52 | 12 | 5 | 32 | | 53 | 15 | 6 | 0 | | 54 | 17 | 5 | 32 | | 55 | 18 | 5 | 32 | | 56 | 20 | 5 | 32 | | 57 | 21 | 5 | 32 | | 58 | 23 | 5 | 32 | | 59 | 24 | 5 | 32 | | 60 | 35 | 6 | 0 | | 61 | 34 | 6 | 0 | | 62 | 33 | 6 | 0 | | 63 | 32 | 6 | 0 | #### Match Length Code: | State | Symbol | Number_Of_Bits | Base | | ----- | ------ | -------------- | ---- | | 0 | 0 | 6 | 0 | | 1 | 1 | 4 | 0 | | 2 | 2 | 5 | 32 | | 3 | 3 | 5 | 0 | | 4 | 5 | 5 | 0 | | 5 | 6 | 5 | 0 | | 6 | 8 | 5 | 0 | | 7 | 10 | 6 | 0 | | 8 | 13 | 6 | 0 | | 9 | 16 | 6 | 0 | | 10 | 19 | 6 | 0 | | 11 | 22 | 6 | 0 | | 12 | 25 | 6 | 0 | | 13 | 28 | 6 | 0 | | 14 | 31 | 6 | 0 | | 15 | 33 | 6 | 0 | | 16 | 35 | 6 | 0 | | 17 | 37 | 6 | 0 | | 18 | 39 | 6 | 0 | | 19 | 41 | 6 | 0 | | 20 | 43 | 6 | 0 | | 21 | 45 | 6 | 0 | | 22 | 1 | 4 | 16 | | 23 | 2 | 4 | 0 | | 24 | 3 | 5 | 32 | | 25 | 4 | 5 | 0 | | 26 | 6 | 5 | 32 | | 27 | 7 | 5 | 0 | | 28 | 9 | 6 | 0 | | 29 | 12 | 6 | 0 | | 30 | 15 | 6 | 0 | | 31 | 18 | 6 | 0 | | 32 | 21 | 6 | 0 | | 33 | 24 | 6 | 0 | | 34 | 27 | 6 | 0 | | 35 | 30 | 6 | 0 | | 36 | 32 | 6 | 0 | | 37 | 34 | 6 | 0 | | 38 | 36 | 6 | 0 | | 39 | 38 | 6 | 0 | | 40 | 40 | 6 | 0 | | 41 | 42 | 6 | 0 | | 42 | 44 | 6 | 0 | | 43 | 1 | 4 | 32 | | 44 | 1 | 4 | 48 | | 45 | 2 | 4 | 16 | | 46 | 4 | 5 | 32 | | 47 | 5 | 5 | 32 | | 48 | 7 | 5 | 32 | | 49 | 8 | 5 | 32 | | 50 | 11 | 6 | 0 | | 51 | 14 | 6 | 0 | | 52 | 17 | 6 | 0 | | 53 | 20 | 6 | 0 | | 54 | 23 | 6 | 0 | | 55 | 26 | 6 | 0 | | 56 | 29 | 6 | 0 | | 57 | 52 | 6 | 0 | | 58 | 51 | 6 | 0 | | 59 | 50 | 6 | 0 | | 60 | 49 | 6 | 0 | | 61 | 48 | 6 | 0 | | 62 | 47 | 6 | 0 | | 63 | 46 | 6 | 0 | #### Offset Code: | State | Symbol | Number_Of_Bits | Base | | ----- | ------ | -------------- | ---- | | 0 | 0 | 5 | 0 | | 1 | 6 | 4 | 0 | | 2 | 9 | 5 | 0 | | 3 | 15 | 5 | 0 | | 4 | 21 | 5 | 0 | | 5 | 3 | 5 | 0 | | 6 | 7 | 4 | 0 | | 7 | 12 | 5 | 0 | | 8 | 18 | 5 | 0 | | 9 | 23 | 5 | 0 | | 10 | 5 | 5 | 0 | | 11 | 8 | 4 | 0 | | 12 | 14 | 5 | 0 | | 13 | 20 | 5 | 0 | | 14 | 2 | 5 | 0 | | 15 | 7 | 4 | 16 | | 16 | 11 | 5 | 0 | | 17 | 17 | 5 | 0 | | 18 | 22 | 5 | 0 | | 19 | 4 | 5 | 0 | | 20 | 8 | 4 | 16 | | 21 | 13 | 5 | 0 | | 22 | 19 | 5 | 0 | | 23 | 1 | 5 | 0 | | 24 | 6 | 4 | 16 | | 25 | 10 | 5 | 0 | | 26 | 16 | 5 | 0 | | 27 | 28 | 5 | 0 | | 28 | 27 | 5 | 0 | | 29 | 26 | 5 | 0 | | 30 | 25 | 5 | 0 | | 31 | 24 | 5 | 0 | Appendix B - Resources for implementers ------------------------------------------------- An open source reference implementation is available on : https://github.com/facebook/zstd The project contains a frame generator, called [decodeCorpus], which can be used by any 3rd-party implementation to verify that a tested decoder is compliant with the specification. [decodeCorpus]: https://github.com/facebook/zstd/tree/v1.3.4/tests#decodecorpus---tool-to-generate-zstandard-frames-for-decoder-testing `decodeCorpus` generates random valid frames. A compliant decoder should be able to decode them all, or at least provide a meaningful error code explaining for which reason it cannot (memory limit restrictions for example). Version changes --------------- +- 0.3.4 : clarifications for FSE decoding table +- 0.3.3 : clarifications for field Block_Size - 0.3.2 : remove additional block size restriction on compressed blocks - 0.3.1 : minor clarification regarding offset history update rules - 0.3.0 : minor edits to match RFC8478 - 0.2.9 : clarifications for huffman weights direct representation, by Ulrich Kunitz - 0.2.8 : clarifications for IETF RFC discuss - 0.2.7 : clarifications from IETF RFC review, by Vijay Gurbani and Nick Terrell - 0.2.6 : fixed an error in huffman example, by Ulrich Kunitz - 0.2.5 : minor typos and clarifications - 0.2.4 : section restructuring, by Sean Purcell - 0.2.3 : clarified several details, by Sean Purcell - 0.2.2 : added predefined codes, by Johannes Rudolph - 0.2.1 : clarify field names, by Przemyslaw Skibinski - 0.2.0 : numerous format adjustments for zstd v0.8+ - 0.1.2 : limit Huffman tree depth to 11 bits - 0.1.1 : reserved dictID ranges - 0.1.0 : initial release Index: head/sys/contrib/zstd/doc/zstd_manual.html =================================================================== --- head/sys/contrib/zstd/doc/zstd_manual.html (revision 354776) +++ head/sys/contrib/zstd/doc/zstd_manual.html (revision 354777) @@ -1,1588 +1,1670 @@ -zstd 1.4.2 Manual +zstd 1.4.4 Manual -

zstd 1.4.2 Manual

+

zstd 1.4.4 Manual

Contents

  1. Introduction
  2. Version
  3. Simple API
  4. Explicit context
  5. Advanced compression API
  6. Advanced decompression API
  7. Streaming
  8. Streaming compression - HowTo
  9. Streaming decompression - HowTo
  10. Simple dictionary API
  11. Bulk processing dictionary API
  12. Dictionary helper functions
  13. Advanced dictionary and prefix API
  14. experimental API (static linking only)
  15. Frame size functions
  16. Memory management
  17. Advanced compression functions
  18. Advanced decompression functions
  19. Advanced streaming functions
    20. -
  20. Buffer-less and synchronous inner streaming functions
    21. -
  21. Buffer-less streaming compression (synchronous mode)
    22. -
  22. Buffer-less streaming decompression (synchronous mode)
    23. -
  23. Block level API
    24. +
  24. ! ZSTD_initCStream_usingDict() :
    25. +
  25. ! ZSTD_initCStream_advanced() :
    26. +
  26. ! ZSTD_initCStream_usingCDict() :
    27. +
  27. ! ZSTD_initCStream_usingCDict_advanced() :
    28. +
  28. This function is deprecated, and is equivalent to:
    29. +
  29. This function is deprecated, and is equivalent to:
    30. +
  30. Buffer-less and synchronous inner streaming functions
    31. +
  31. Buffer-less streaming compression (synchronous mode)
    32. +
  32. Buffer-less streaming decompression (synchronous mode)
    33. +
  33. Block level API

Introduction

   zstd, short for Zstandard, is a fast lossless compression algorithm, targeting
   real-time compression scenarios at zlib-level and better compression ratios.
   The zstd compression library provides in-memory compression and decompression
   functions.
 
   The library supports regular compression levels from 1 up to ZSTD_maxCLevel(),
   which is currently 22. Levels >= 20, labeled `--ultra`, should be used with
   caution, as they require more memory. The library also offers negative
   compression levels, which extend the range of speed vs. ratio preferences.
   The lower the level, the faster the speed (at the cost of compression).
 
   Compression can be done in:
     - a single step (described as Simple API)
     - a single step, reusing a context (described as Explicit context)
     - unbounded multiple steps (described as Streaming compression)
 
   The compression ratio achievable on small data can be highly improved using
   a dictionary. Dictionary compression can be performed in:
     - a single step (described as Simple dictionary API)
     - a single step, reusing a dictionary (described as Bulk-processing
       dictionary API)
 
   Advanced experimental functions can be accessed using
   `#define ZSTD_STATIC_LINKING_ONLY` before including zstd.h.
 
   Advanced experimental APIs should never be used with a dynamically-linked
   library. They are not "stable"; their definitions or signatures may change in
   the future. Only static linking is allowed.

Version


 
 
unsigned ZSTD_versionNumber(void);   /**< to check runtime library version */
 


 
Simple API

 
 
size_t ZSTD_compress( void* dst, size_t dstCapacity,
                 const void* src, size_t srcSize,
                       int compressionLevel);
 
  Compresses `src` content as a single zstd compressed frame into already allocated `dst`.
   Hint : compression runs faster if `dstCapacity` >=  `ZSTD_compressBound(srcSize)`.
   @return : compressed size written into `dst` (<= `dstCapacity),
             or an error code if it fails (which can be tested using ZSTD_isError()). 
 


 
 
size_t ZSTD_decompress( void* dst, size_t dstCapacity,
                   const void* src, size_t compressedSize);
 
  `compressedSize` : must be the _exact_ size of some number of compressed and/or skippable frames.
   `dstCapacity` is an upper bound of originalSize to regenerate.
   If user cannot imply a maximum upper bound, it's better to use streaming mode to decompress data.
   @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
             or an errorCode if it fails (which can be tested using ZSTD_isError()). 
 


 
 
#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
 #define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
 unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
 
  `src` should point to the start of a ZSTD encoded frame.
   `srcSize` must be at least as large as the frame header.
             hint : any size >= `ZSTD_frameHeaderSize_max` is large enough.
   @return : - decompressed size of `src` frame content, if known
             - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
             - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small)
    note 1 : a 0 return value means the frame is valid but "empty".
    note 2 : decompressed size is an optional field, it may not be present, typically in streaming mode.
             When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
             In which case, it's necessary to use streaming mode to decompress data.
             Optionally, application can rely on some implicit limit,
             as ZSTD_decompress() only needs an upper bound of decompressed size.
             (For example, data could be necessarily cut into blocks <= 16 KB).
    note 3 : decompressed size is always present when compression is completed using single-pass functions,
             such as ZSTD_compress(), ZSTD_compressCCtx() ZSTD_compress_usingDict() or ZSTD_compress_usingCDict().
    note 4 : decompressed size can be very large (64-bits value),
             potentially larger than what local system can handle as a single memory segment.
             In which case, it's necessary to use streaming mode to decompress data.
    note 5 : If source is untrusted, decompressed size could be wrong or intentionally modified.
             Always ensure return value fits within application's authorized limits.
             Each application can set its own limits.
    note 6 : This function replaces ZSTD_getDecompressedSize() 
 


 
 
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
 
  NOTE: This function is now obsolete, in favor of ZSTD_getFrameContentSize().
   Both functions work the same way, but ZSTD_getDecompressedSize() blends
   "empty", "unknown" and "error" results to the same return value (0),
   while ZSTD_getFrameContentSize() gives them separate return values.
  @return : decompressed size of `src` frame content _if known and not empty_, 0 otherwise. 
 


 
 
size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);
 
 `src` should point to the start of a ZSTD frame or skippable frame.
  `srcSize` must be >= first frame size
  @return : the compressed size of the first frame starting at `src`,
            suitable to pass as `srcSize` to `ZSTD_decompress` or similar,
         or an error code if input is invalid 
 


 
 
Helper functions
#define ZSTD_COMPRESSBOUND(srcSize)   ((srcSize) + ((srcSize)>>8) + (((srcSize) < (128<<10)) ? (((128<<10) - (srcSize)) >> 11) /* margin, from 64 to 0 */ : 0))  /* this formula ensures that bound(A) + bound(B) <= bound(A+B) as long as A and B >= 128 KB */
 size_t      ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case single-pass scenario */
 unsigned    ZSTD_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */
 const char* ZSTD_getErrorName(size_t code);     /*!< provides readable string from an error code */
 int         ZSTD_minCLevel(void);               /*!< minimum negative compression level allowed */
 int         ZSTD_maxCLevel(void);               /*!< maximum compression level available */
 


 
Explicit context

 
 
Compression context
  When compressing many times,
   it is recommended to allocate a context just once,
   and re-use it for each successive compression operation.
   This will make workload friendlier for system's memory.
   Note : re-using context is just a speed / resource optimization.
          It doesn't change the compression ratio, which remains identical.
   Note 2 : In multi-threaded environments,
          use one different context per thread for parallel execution.
  
 
typedef struct ZSTD_CCtx_s ZSTD_CCtx;
 ZSTD_CCtx* ZSTD_createCCtx(void);
 size_t     ZSTD_freeCCtx(ZSTD_CCtx* cctx);
 


 
size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx,
                          void* dst, size_t dstCapacity,
                    const void* src, size_t srcSize,
                          int compressionLevel);
-
  Same as ZSTD_compress(), using an explicit ZSTD_CCtx
-  The function will compress at requested compression level,
-  ignoring any other parameter 
+
  Same as ZSTD_compress(), using an explicit ZSTD_CCtx.
+  Important : in order to behave similarly to `ZSTD_compress()`,
+  this function compresses at requested compression level,
+  __ignoring any other parameter__ .
+  If any advanced parameter was set using the advanced API,
+  they will all be reset. Only `compressionLevel` remains.
+ 
 


 
 
Decompression context
  When decompressing many times,
   it is recommended to allocate a context only once,
   and re-use it for each successive compression operation.
   This will make workload friendlier for system's memory.
   Use one context per thread for parallel execution. 
 
typedef struct ZSTD_DCtx_s ZSTD_DCtx;
 ZSTD_DCtx* ZSTD_createDCtx(void);
 size_t     ZSTD_freeDCtx(ZSTD_DCtx* dctx);
 


 
size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx,
                            void* dst, size_t dstCapacity,
                      const void* src, size_t srcSize);
 
  Same as ZSTD_decompress(),
   requires an allocated ZSTD_DCtx.
   Compatible with sticky parameters.
  
 


 
 
Advanced compression API

 
 
typedef enum { ZSTD_fast=1,
                ZSTD_dfast=2,
                ZSTD_greedy=3,
                ZSTD_lazy=4,
                ZSTD_lazy2=5,
                ZSTD_btlazy2=6,
                ZSTD_btopt=7,
                ZSTD_btultra=8,
                ZSTD_btultra2=9
                /* note : new strategies _might_ be added in the future.
                          Only the order (from fast to strong) is guaranteed */
 } ZSTD_strategy;
 


 
typedef enum {
 
     /* compression parameters
      * Note: When compressing with a ZSTD_CDict these parameters are superseded
-     * by the parameters used to construct the ZSTD_CDict. See ZSTD_CCtx_refCDict()
-     * for more info (superseded-by-cdict). */
-    ZSTD_c_compressionLevel=100, /* Update all compression parameters according to pre-defined cLevel table
+     * by the parameters used to construct the ZSTD_CDict.
+     * See ZSTD_CCtx_refCDict() for more info (superseded-by-cdict). */
+    ZSTD_c_compressionLevel=100, /* Set compression parameters according to pre-defined cLevel table.
+                              * Note that exact compression parameters are dynamically determined,
+                              * depending on both compression level and srcSize (when known).
                               * Default level is ZSTD_CLEVEL_DEFAULT==3.
                               * Special: value 0 means default, which is controlled by ZSTD_CLEVEL_DEFAULT.
                               * Note 1 : it's possible to pass a negative compression level.
-                              * Note 2 : setting a level sets all default values of other compression parameters */
+                              * Note 2 : setting a level resets all other compression parameters to default */
+    /* Advanced compression parameters :
+     * It's possible to pin down compression parameters to some specific values.
+     * In which case, these values are no longer dynamically selected by the compressor */
     ZSTD_c_windowLog=101,    /* Maximum allowed back-reference distance, expressed as power of 2.
+                              * This will set a memory budget for streaming decompression,
+                              * with larger values requiring more memory
+                              * and typically compressing more.
                               * Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
                               * Special: value 0 means "use default windowLog".
                               * Note: Using a windowLog greater than ZSTD_WINDOWLOG_LIMIT_DEFAULT
-                              *       requires explicitly allowing such window size at decompression stage if using streaming. */
+                              *       requires explicitly allowing such size at streaming decompression stage. */
     ZSTD_c_hashLog=102,      /* Size of the initial probe table, as a power of 2.
                               * Resulting memory usage is (1 << (hashLog+2)).
                               * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
                               * Larger tables improve compression ratio of strategies <= dFast,
                               * and improve speed of strategies > dFast.
                               * Special: value 0 means "use default hashLog". */
     ZSTD_c_chainLog=103,     /* Size of the multi-probe search table, as a power of 2.
                               * Resulting memory usage is (1 << (chainLog+2)).
                               * Must be clamped between ZSTD_CHAINLOG_MIN and ZSTD_CHAINLOG_MAX.
                               * Larger tables result in better and slower compression.
-                              * This parameter is useless when using "fast" strategy.
+                              * This parameter is useless for "fast" strategy.
                               * It's still useful when using "dfast" strategy,
                               * in which case it defines a secondary probe table.
                               * Special: value 0 means "use default chainLog". */
     ZSTD_c_searchLog=104,    /* Number of search attempts, as a power of 2.
                               * More attempts result in better and slower compression.
-                              * This parameter is useless when using "fast" and "dFast" strategies.
+                              * This parameter is useless for "fast" and "dFast" strategies.
                               * Special: value 0 means "use default searchLog". */
     ZSTD_c_minMatch=105,     /* Minimum size of searched matches.
                               * Note that Zstandard can still find matches of smaller size,
                               * it just tweaks its search algorithm to look for this size and larger.
                               * Larger values increase compression and decompression speed, but decrease ratio.
                               * Must be clamped between ZSTD_MINMATCH_MIN and ZSTD_MINMATCH_MAX.
                               * Note that currently, for all strategies < btopt, effective minimum is 4.
                               *                    , for all strategies > fast, effective maximum is 6.
                               * Special: value 0 means "use default minMatchLength". */
     ZSTD_c_targetLength=106, /* Impact of this field depends on strategy.
                               * For strategies btopt, btultra & btultra2:
                               *     Length of Match considered "good enough" to stop search.
                               *     Larger values make compression stronger, and slower.
                               * For strategy fast:
                               *     Distance between match sampling.
                               *     Larger values make compression faster, and weaker.
                               * Special: value 0 means "use default targetLength". */
     ZSTD_c_strategy=107,     /* See ZSTD_strategy enum definition.
                               * The higher the value of selected strategy, the more complex it is,
                               * resulting in stronger and slower compression.
                               * Special: value 0 means "use default strategy". */
 
     /* LDM mode parameters */
     ZSTD_c_enableLongDistanceMatching=160, /* Enable long distance matching.
                                      * This parameter is designed to improve compression ratio
                                      * for large inputs, by finding large matches at long distance.
                                      * It increases memory usage and window size.
                                      * Note: enabling this parameter increases default ZSTD_c_windowLog to 128 MB
                                      * except when expressly set to a different value. */
     ZSTD_c_ldmHashLog=161,   /* Size of the table for long distance matching, as a power of 2.
                               * Larger values increase memory usage and compression ratio,
                               * but decrease compression speed.
                               * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX
                               * default: windowlog - 7.
                               * Special: value 0 means "automatically determine hashlog". */
     ZSTD_c_ldmMinMatch=162,  /* Minimum match size for long distance matcher.
                               * Larger/too small values usually decrease compression ratio.
                               * Must be clamped between ZSTD_LDM_MINMATCH_MIN and ZSTD_LDM_MINMATCH_MAX.
                               * Special: value 0 means "use default value" (default: 64). */
     ZSTD_c_ldmBucketSizeLog=163, /* Log size of each bucket in the LDM hash table for collision resolution.
                               * Larger values improve collision resolution but decrease compression speed.
                               * The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX.
                               * Special: value 0 means "use default value" (default: 3). */
     ZSTD_c_ldmHashRateLog=164, /* Frequency of inserting/looking up entries into the LDM hash table.
                               * Must be clamped between 0 and (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN).
                               * Default is MAX(0, (windowLog - ldmHashLog)), optimizing hash table usage.
                               * Larger values improve compression speed.
                               * Deviating far from default value will likely result in a compression ratio decrease.
                               * Special: value 0 means "automatically determine hashRateLog". */
 
     /* frame parameters */
     ZSTD_c_contentSizeFlag=200, /* Content size will be written into frame header _whenever known_ (default:1)
                               * Content size must be known at the beginning of compression.
                               * This is automatically the case when using ZSTD_compress2(),
-                              * For streaming variants, content size must be provided with ZSTD_CCtx_setPledgedSrcSize() */
+                              * For streaming scenarios, content size must be provided with ZSTD_CCtx_setPledgedSrcSize() */
     ZSTD_c_checksumFlag=201, /* A 32-bits checksum of content is written at end of frame (default:0) */
     ZSTD_c_dictIDFlag=202,   /* When applicable, dictionary's ID is written into frame header (default:1) */
 
     /* multi-threading parameters */
     /* These parameters are only useful if multi-threading is enabled (compiled with build macro ZSTD_MULTITHREAD).
      * They return an error otherwise. */
     ZSTD_c_nbWorkers=400,    /* Select how many threads will be spawned to compress in parallel.
                               * When nbWorkers >= 1, triggers asynchronous mode when used with ZSTD_compressStream*() :
                               * ZSTD_compressStream*() consumes input and flush output if possible, but immediately gives back control to caller,
                               * while compression work is performed in parallel, within worker threads.
                               * (note : a strong exception to this rule is when first invocation of ZSTD_compressStream2() sets ZSTD_e_end :
                               *  in which case, ZSTD_compressStream2() delegates to ZSTD_compress2(), which is always a blocking call).
                               * More workers improve speed, but also increase memory usage.
                               * Default value is `0`, aka "single-threaded mode" : no worker is spawned, compression is performed inside Caller's thread, all invocations are blocking */
     ZSTD_c_jobSize=401,      /* Size of a compression job. This value is enforced only when nbWorkers >= 1.
                               * Each compression job is completed in parallel, so this value can indirectly impact the nb of active threads.
                               * 0 means default, which is dynamically determined based on compression parameters.
                               * Job size must be a minimum of overlap size, or 1 MB, whichever is largest.
-                              * The minimum size is automatically and transparently enforced */
+                              * The minimum size is automatically and transparently enforced. */
     ZSTD_c_overlapLog=402,   /* Control the overlap size, as a fraction of window size.
                               * The overlap size is an amount of data reloaded from previous job at the beginning of a new job.
                               * It helps preserve compression ratio, while each job is compressed in parallel.
                               * This value is enforced only when nbWorkers >= 1.
                               * Larger values increase compression ratio, but decrease speed.
                               * Possible values range from 0 to 9 :
                               * - 0 means "default" : value will be determined by the library, depending on strategy
                               * - 1 means "no overlap"
                               * - 9 means "full overlap", using a full window size.
                               * Each intermediate rank increases/decreases load size by a factor 2 :
                               * 9: full window;  8: w/2;  7: w/4;  6: w/8;  5:w/16;  4: w/32;  3:w/64;  2:w/128;  1:no overlap;  0:default
                               * default value varies between 6 and 9, depending on strategy */
 
     /* note : additional experimental parameters are also available
      * within the experimental section of the API.
      * At the time of this writing, they include :
      * ZSTD_c_rsyncable
      * ZSTD_c_format
      * ZSTD_c_forceMaxWindow
      * ZSTD_c_forceAttachDict
      * ZSTD_c_literalCompressionMode
      * ZSTD_c_targetCBlockSize
+     * ZSTD_c_srcSizeHint
      * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
      * note : never ever use experimentalParam? names directly;
      *        also, the enums values themselves are unstable and can still change.
      */
      ZSTD_c_experimentalParam1=500,
      ZSTD_c_experimentalParam2=10,
      ZSTD_c_experimentalParam3=1000,
      ZSTD_c_experimentalParam4=1001,
      ZSTD_c_experimentalParam5=1002,
      ZSTD_c_experimentalParam6=1003,
+     ZSTD_c_experimentalParam7=1004
 } ZSTD_cParameter;
 


 
typedef struct {
     size_t error;
     int lowerBound;
     int upperBound;
 } ZSTD_bounds;
 


 
ZSTD_bounds ZSTD_cParam_getBounds(ZSTD_cParameter cParam);
 
  All parameters must belong to an interval with lower and upper bounds,
   otherwise they will either trigger an error or be automatically clamped.
  @return : a structure, ZSTD_bounds, which contains
          - an error status field, which must be tested using ZSTD_isError()
          - lower and upper bounds, both inclusive
  
 


 
 
size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int value);
 
  Set one compression parameter, selected by enum ZSTD_cParameter.
   All parameters have valid bounds. Bounds can be queried using ZSTD_cParam_getBounds().
   Providing a value beyond bound will either clamp it, or trigger an error (depending on parameter).
   Setting a parameter is generally only possible during frame initialization (before starting compression).
   Exception : when using multi-threading mode (nbWorkers >= 1),
               the following parameters can be updated _during_ compression (within same frame):
               => compressionLevel, hashLog, chainLog, searchLog, minMatch, targetLength and strategy.
               new parameters will be active for next job only (after a flush()).
  @return : an error code (which can be tested using ZSTD_isError()).
  
 


 
 
size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);
 
  Total input data size to be compressed as a single frame.
   Value will be written in frame header, unless if explicitly forbidden using ZSTD_c_contentSizeFlag.
   This value will also be controlled at end of frame, and trigger an error if not respected.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Note 1 : pledgedSrcSize==0 actually means zero, aka an empty frame.
            In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
            ZSTD_CONTENTSIZE_UNKNOWN is default value for any new frame.
   Note 2 : pledgedSrcSize is only valid once, for the next frame.
            It's discarded at the end of the frame, and replaced by ZSTD_CONTENTSIZE_UNKNOWN.
   Note 3 : Whenever all input data is provided and consumed in a single round,
            for example with ZSTD_compress2(),
            or invoking immediately ZSTD_compressStream2(,,,ZSTD_e_end),
            this value is automatically overridden by srcSize instead.
  
 


 
 
typedef enum {
     ZSTD_reset_session_only = 1,
     ZSTD_reset_parameters = 2,
     ZSTD_reset_session_and_parameters = 3
 } ZSTD_ResetDirective;
 


 
size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx, ZSTD_ResetDirective reset);
 
  There are 2 different things that can be reset, independently or jointly :
   - The session : will stop compressing current frame, and make CCtx ready to start a new one.
                   Useful after an error, or to interrupt any ongoing compression.
                   Any internal data not yet flushed is cancelled.
                   Compression parameters and dictionary remain unchanged.
                   They will be used to compress next frame.
                   Resetting session never fails.
   - The parameters : changes all parameters back to "default".
                   This removes any reference to any dictionary too.
                   Parameters can only be changed between 2 sessions (i.e. no compression is currently ongoing)
                   otherwise the reset fails, and function returns an error value (which can be tested using ZSTD_isError())
   - Both : similar to resetting the session, followed by resetting parameters.
  
 


 
 
size_t ZSTD_compress2( ZSTD_CCtx* cctx,
                        void* dst, size_t dstCapacity,
                  const void* src, size_t srcSize);
 
  Behave the same as ZSTD_compressCCtx(), but compression parameters are set using the advanced API.
   ZSTD_compress2() always starts a new frame.
   Should cctx hold data from a previously unfinished frame, everything about it is forgotten.
   - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*()
   - The function is always blocking, returns when compression is completed.
   Hint : compression runs faster if `dstCapacity` >=  `ZSTD_compressBound(srcSize)`.
  @return : compressed size written into `dst` (<= `dstCapacity),
            or an error code if it fails (which can be tested using ZSTD_isError()).
  
 


 
 
Advanced decompression API

 
 
typedef enum {
 
     ZSTD_d_windowLogMax=100, /* Select a size limit (in power of 2) beyond which
                               * the streaming API will refuse to allocate memory buffer
                               * in order to protect the host from unreasonable memory requirements.
                               * This parameter is only useful in streaming mode, since no internal buffer is allocated in single-pass mode.
                               * By default, a decompression context accepts window sizes <= (1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT).
                               * Special: value 0 means "use default maximum windowLog". */
 
     /* note : additional experimental parameters are also available
      * within the experimental section of the API.
      * At the time of this writing, they include :
      * ZSTD_c_format
      * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
      * note : never ever use experimentalParam? names directly
      */
      ZSTD_d_experimentalParam1=1000
 
 } ZSTD_dParameter;
 


 
ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam);
 
  All parameters must belong to an interval with lower and upper bounds,
   otherwise they will either trigger an error or be automatically clamped.
  @return : a structure, ZSTD_bounds, which contains
          - an error status field, which must be tested using ZSTD_isError()
          - both lower and upper bounds, inclusive
  
 


 
 
size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int value);
 
  Set one compression parameter, selected by enum ZSTD_dParameter.
   All parameters have valid bounds. Bounds can be queried using ZSTD_dParam_getBounds().
   Providing a value beyond bound will either clamp it, or trigger an error (depending on parameter).
   Setting a parameter is only possible during frame initialization (before starting decompression).
  @return : 0, or an error code (which can be tested using ZSTD_isError()).
  
 


 
 
size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset);
 
  Return a DCtx to clean state.
   Session and parameters can be reset jointly or separately.
   Parameters can only be reset when no active frame is being decompressed.
  @return : 0, or an error code, which can be tested with ZSTD_isError()
  
 


 
 
Streaming

 
 
typedef struct ZSTD_inBuffer_s {
   const void* src;    /**< start of input buffer */
   size_t size;        /**< size of input buffer */
   size_t pos;         /**< position where reading stopped. Will be updated. Necessarily 0 <= pos <= size */
 } ZSTD_inBuffer;
 


 
typedef struct ZSTD_outBuffer_s {
   void*  dst;         /**< start of output buffer */
   size_t size;        /**< size of output buffer */
   size_t pos;         /**< position where writing stopped. Will be updated. Necessarily 0 <= pos <= size */
 } ZSTD_outBuffer;
 


 
Streaming compression - HowTo
   A ZSTD_CStream object is required to track streaming operation.
   Use ZSTD_createCStream() and ZSTD_freeCStream() to create/release resources.
   ZSTD_CStream objects can be reused multiple times on consecutive compression operations.
   It is recommended to re-use ZSTD_CStream since it will play nicer with system's memory, by re-using already allocated memory.
 
   For parallel execution, use one separate ZSTD_CStream per thread.
 
   note : since v1.3.0, ZSTD_CStream and ZSTD_CCtx are the same thing.
 
   Parameters are sticky : when starting a new compression on the same context,
   it will re-use the same sticky parameters as previous compression session.
   When in doubt, it's recommended to fully initialize the context before usage.
   Use ZSTD_CCtx_reset() to reset the context and ZSTD_CCtx_setParameter(),
   ZSTD_CCtx_setPledgedSrcSize(), or ZSTD_CCtx_loadDictionary() and friends to
   set more specific parameters, the pledged source size, or load a dictionary.
 
   Use ZSTD_compressStream2() with ZSTD_e_continue as many times as necessary to
   consume input stream. The function will automatically update both `pos`
   fields within `input` and `output`.
   Note that the function may not consume the entire input, for example, because
   the output buffer is already full, in which case `input.pos < input.size`.
   The caller must check if input has been entirely consumed.
   If not, the caller must make some room to receive more compressed data,
   and then present again remaining input data.
   note: ZSTD_e_continue is guaranteed to make some forward progress when called,
         but doesn't guarantee maximal forward progress. This is especially relevant
         when compressing with multiple threads. The call won't block if it can
         consume some input, but if it can't it will wait for some, but not all,
         output to be flushed.
  @return : provides a minimum amount of data remaining to be flushed from internal buffers
            or an error code, which can be tested using ZSTD_isError().
 
   At any moment, it's possible to flush whatever data might remain stuck within internal buffer,
   using ZSTD_compressStream2() with ZSTD_e_flush. `output->pos` will be updated.
   Note that, if `output->size` is too small, a single invocation with ZSTD_e_flush might not be enough (return code > 0).
   In which case, make some room to receive more compressed data, and call again ZSTD_compressStream2() with ZSTD_e_flush.
   You must continue calling ZSTD_compressStream2() with ZSTD_e_flush until it returns 0, at which point you can change the
   operation.
   note: ZSTD_e_flush will flush as much output as possible, meaning when compressing with multiple threads, it will
         block until the flush is complete or the output buffer is full.
   @return : 0 if internal buffers are entirely flushed,
             >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
             or an error code, which can be tested using ZSTD_isError().
 
   Calling ZSTD_compressStream2() with ZSTD_e_end instructs to finish a frame.
   It will perform a flush and write frame epilogue.
   The epilogue is required for decoders to consider a frame completed.
   flush operation is the same, and follows same rules as calling ZSTD_compressStream2() with ZSTD_e_flush.
   You must continue calling ZSTD_compressStream2() with ZSTD_e_end until it returns 0, at which point you are free to
   start a new frame.
   note: ZSTD_e_end will flush as much output as possible, meaning when compressing with multiple threads, it will
         block until the flush is complete or the output buffer is full.
   @return : 0 if frame fully completed and fully flushed,
             >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
             or an error code, which can be tested using ZSTD_isError().
 
  
 

 
 
typedef ZSTD_CCtx ZSTD_CStream;  /**< CCtx and CStream are now effectively same object (>= v1.3.0) */
 


 
ZSTD_CStream management functions
ZSTD_CStream* ZSTD_createCStream(void);
 size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
 


 
Streaming compression functions
typedef enum {
     ZSTD_e_continue=0, /* collect more data, encoder decides when to output compressed result, for optimal compression ratio */
     ZSTD_e_flush=1,    /* flush any data provided so far,
                         * it creates (at least) one new block, that can be decoded immediately on reception;
                         * frame will continue: any future data can still reference previously compressed data, improving compression.
                         * note : multithreaded compression will block to flush as much output as possible. */
     ZSTD_e_end=2       /* flush any remaining data _and_ close current frame.
                         * note that frame is only closed after compressed data is fully flushed (return value == 0).
                         * After that point, any additional data starts a new frame.
                         * note : each frame is independent (does not reference any content from previous frame).
                         : note : multithreaded compression will block to flush as much output as possible. */
 } ZSTD_EndDirective;
 


 
size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
                              ZSTD_outBuffer* output,
                              ZSTD_inBuffer* input,
                              ZSTD_EndDirective endOp);
 
  Behaves about the same as ZSTD_compressStream, with additional control on end directive.
   - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*()
   - Compression parameters cannot be changed once compression is started (save a list of exceptions in multi-threading mode)
   - output->pos must be <= dstCapacity, input->pos must be <= srcSize
   - output->pos and input->pos will be updated. They are guaranteed to remain below their respective limit.
   - When nbWorkers==0 (default), function is blocking : it completes its job before returning to caller.
   - When nbWorkers>=1, function is non-blocking : it just acquires a copy of input, and distributes jobs to internal worker threads, flush whatever is available,
                                                   and then immediately returns, just indicating that there is some data remaining to be flushed.
                                                   The function nonetheless guarantees forward progress : it will return only after it reads or write at least 1+ byte.
   - Exception : if the first call requests a ZSTD_e_end directive and provides enough dstCapacity, the function delegates to ZSTD_compress2() which is always blocking.
   - @return provides a minimum amount of data remaining to be flushed from internal buffers
             or an error code, which can be tested using ZSTD_isError().
             if @return != 0, flush is not fully completed, there is still some data left within internal buffers.
             This is useful for ZSTD_e_flush, since in this case more flushes are necessary to empty all buffers.
             For ZSTD_e_end, @return == 0 when internal buffers are fully flushed and frame is completed.
   - after a ZSTD_e_end directive, if internal buffer is not fully flushed (@return != 0),
             only ZSTD_e_end or ZSTD_e_flush operations are allowed.
             Before starting a new compression job, or changing compression parameters,
             it is required to fully flush internal buffers.
  
 


 
 
size_t ZSTD_CStreamInSize(void);    /**< recommended size for input buffer */
 


 
size_t ZSTD_CStreamOutSize(void);   /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block. */
 


 
size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
 /*!
  * Alternative for ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue).
  * NOTE: The return value is different. ZSTD_compressStream() returns a hint for
  * the next read size (if non-zero and not an error). ZSTD_compressStream2()
  * returns the minimum nb of bytes left to flush (if non-zero and not an error).
  */
 size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
 /*! Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_flush). */
 size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
 /*! Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_end). */
 size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
 

      ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
      ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any)
      ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
  
 


 
 
Streaming decompression - HowTo
   A ZSTD_DStream object is required to track streaming operations.
   Use ZSTD_createDStream() and ZSTD_freeDStream() to create/release resources.
   ZSTD_DStream objects can be re-used multiple times.
 
   Use ZSTD_initDStream() to start a new decompression operation.
  @return : recommended first input size
   Alternatively, use advanced API to set specific properties.
 
   Use ZSTD_decompressStream() repetitively to consume your input.
   The function will update both `pos` fields.
   If `input.pos < input.size`, some input has not been consumed.
   It's up to the caller to present again remaining data.
   The function tries to flush all data decoded immediately, respecting output buffer size.
   If `output.pos < output.size`, decoder has flushed everything it could.
   But if `output.pos == output.size`, there might be some data left within internal buffers.,
   In which case, call ZSTD_decompressStream() again to flush whatever remains in the buffer.
   Note : with no additional input provided, amount of data flushed is necessarily <= ZSTD_BLOCKSIZE_MAX.
  @return : 0 when a frame is completely decoded and fully flushed,
         or an error code, which can be tested using ZSTD_isError(),
         or any other value > 0, which means there is still some decoding or flushing to do to complete current frame :
                                 the return value is a suggested next input size (just a hint for better latency)
                                 that will never request more than the remaining frame size.
  
 

 
 
typedef ZSTD_DCtx ZSTD_DStream;  /**< DCtx and DStream are now effectively same object (>= v1.3.0) */
 


 
ZSTD_DStream management functions
ZSTD_DStream* ZSTD_createDStream(void);
 size_t ZSTD_freeDStream(ZSTD_DStream* zds);
 


 
Streaming decompression functions


 
size_t ZSTD_DStreamInSize(void);    /*!< recommended size for input buffer */
 


 
size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */
 


 
Simple dictionary API

 
 
size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                          const void* dict,size_t dictSize,
                                int compressionLevel);
 
  Compression at an explicit compression level using a Dictionary.
   A dictionary can be any arbitrary data segment (also called a prefix),
   or a buffer with specified information (see dictBuilder/zdict.h).
   Note : This function loads the dictionary, resulting in significant startup delay.
          It's intended for a dictionary used only once.
   Note 2 : When `dict == NULL || dictSize < 8` no dictionary is used. 
 


 
 
size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
                                  void* dst, size_t dstCapacity,
                            const void* src, size_t srcSize,
                            const void* dict,size_t dictSize);
 
  Decompression using a known Dictionary.
   Dictionary must be identical to the one used during compression.
   Note : This function loads the dictionary, resulting in significant startup delay.
          It's intended for a dictionary used only once.
   Note : When `dict == NULL || dictSize < 8` no dictionary is used. 
 


 
 
Bulk processing dictionary API

 
 
ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize,
                              int compressionLevel);
-
  When compressing multiple messages / blocks using the same dictionary, it's recommended to load it only once.
-  ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup cost.
+
  When compressing multiple messages or blocks using the same dictionary,
+  it's recommended to digest the dictionary only once, since it's a costly operation.
+  ZSTD_createCDict() will create a state from digesting a dictionary.
+  The resulting state can be used for future compression operations with very limited startup cost.
   ZSTD_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
- `dictBuffer` can be released after ZSTD_CDict creation, because its content is copied within CDict.
-  Consider experimental function `ZSTD_createCDict_byReference()` if you prefer to not duplicate `dictBuffer` content.
-  Note : A ZSTD_CDict can be created from an empty dictBuffer, but it is inefficient when used to compress small data. 
+ @dictBuffer can be released after ZSTD_CDict creation, because its content is copied within CDict.
+  Note 1 : Consider experimental function `ZSTD_createCDict_byReference()` if you prefer to not duplicate @dictBuffer content.
+  Note 2 : A ZSTD_CDict can be created from an empty @dictBuffer,
+      in which case the only thing that it transports is the @compressionLevel.
+      This can be useful in a pipeline featuring ZSTD_compress_usingCDict() exclusively,
+      expecting a ZSTD_CDict parameter with any data, including those without a known dictionary. 
 


 
 
size_t      ZSTD_freeCDict(ZSTD_CDict* CDict);
 
  Function frees memory allocated by ZSTD_createCDict(). 
 


 
 
size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
                                 void* dst, size_t dstCapacity,
                           const void* src, size_t srcSize,
                           const ZSTD_CDict* cdict);
 
  Compression using a digested Dictionary.
   Recommended when same dictionary is used multiple times.
   Note : compression level is _decided at dictionary creation time_,
      and frame parameters are hardcoded (dictID=yes, contentSize=yes, checksum=no) 
 


 
 
ZSTD_DDict* ZSTD_createDDict(const void* dictBuffer, size_t dictSize);
 
  Create a digested dictionary, ready to start decompression operation without startup delay.
   dictBuffer can be released after DDict creation, as its content is copied inside DDict. 
 


 
 
size_t      ZSTD_freeDDict(ZSTD_DDict* ddict);
 
  Function frees memory allocated with ZSTD_createDDict() 
 


 
 
size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
                                   void* dst, size_t dstCapacity,
                             const void* src, size_t srcSize,
                             const ZSTD_DDict* ddict);
 
  Decompression using a digested Dictionary.
   Recommended when same dictionary is used multiple times. 
 


 
 
Dictionary helper functions

 
 
unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize);
 
  Provides the dictID stored within dictionary.
   if @return == 0, the dictionary is not conformant with Zstandard specification.
   It can still be loaded, but as a content-only dictionary. 
 


 
 
unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict);
 
  Provides the dictID of the dictionary loaded into `ddict`.
   If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
   Non-conformant dictionaries can still be loaded, but as content-only dictionaries. 
 


 
 
unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
 
  Provides the dictID required to decompressed the frame stored within `src`.
   If @return == 0, the dictID could not be decoded.
   This could for one of the following reasons :
   - The frame does not require a dictionary to be decoded (most common case).
   - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information.
     Note : this use case also happens when using a non-conformant dictionary.
   - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
   - This is not a Zstandard frame.
   When identifying the exact failure cause, it's possible to use ZSTD_getFrameHeader(), which will provide a more precise error code. 
 


 
 
Advanced dictionary and prefix API
  This API allows dictionaries to be used with ZSTD_compress2(),
  ZSTD_compressStream2(), and ZSTD_decompress(). Dictionaries are sticky, and
  only reset with the context is reset with ZSTD_reset_parameters or
  ZSTD_reset_session_and_parameters. Prefixes are single-use.
 

 
 
size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
 
  Create an internal CDict from `dict` buffer.
   Decompression will have to use same dictionary.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Special: Loading a NULL (or 0-size) dictionary invalidates previous dictionary,
            meaning "return to no-dictionary mode".
   Note 1 : Dictionary is sticky, it will be used for all future compressed frames.
            To return to "no-dictionary" situation, load a NULL dictionary (or reset parameters).
   Note 2 : Loading a dictionary involves building tables.
            It's also a CPU consuming operation, with non-negligible impact on latency.
            Tables are dependent on compression parameters, and for this reason,
            compression parameters can no longer be changed after loading a dictionary.
   Note 3 :`dict` content will be copied internally.
            Use experimental ZSTD_CCtx_loadDictionary_byReference() to reference content instead.
            In such a case, dictionary buffer must outlive its users.
   Note 4 : Use ZSTD_CCtx_loadDictionary_advanced()
            to precisely select how dictionary content must be interpreted. 
 


 
 
size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
 
  Reference a prepared dictionary, to be used for all next compressed frames.
   Note that compression parameters are enforced from within CDict,
   and supersede any compression parameter previously set within CCtx.
   The parameters ignored are labled as "superseded-by-cdict" in the ZSTD_cParameter enum docs.
   The ignored parameters will be used again if the CCtx is returned to no-dictionary mode.
   The dictionary will remain valid for future compressed frames using same CCtx.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Special : Referencing a NULL CDict means "return to no-dictionary mode".
   Note 1 : Currently, only one dictionary can be managed.
            Referencing a new dictionary effectively "discards" any previous one.
   Note 2 : CDict is just referenced, its lifetime must outlive its usage within CCtx. 
 


 
 
size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx,
                      const void* prefix, size_t prefixSize);
 
  Reference a prefix (single-usage dictionary) for next compressed frame.
   A prefix is **only used once**. Tables are discarded at end of frame (ZSTD_e_end).
   Decompression will need same prefix to properly regenerate data.
   Compressing with a prefix is similar in outcome as performing a diff and compressing it,
   but performs much faster, especially during decompression (compression speed is tunable with compression level).
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Special: Adding any prefix (including NULL) invalidates any previous prefix or dictionary
   Note 1 : Prefix buffer is referenced. It **must** outlive compression.
            Its content must remain unmodified during compression.
   Note 2 : If the intention is to diff some large src data blob with some prior version of itself,
            ensure that the window size is large enough to contain the entire source.
            See ZSTD_c_windowLog.
   Note 3 : Referencing a prefix involves building tables, which are dependent on compression parameters.
            It's a CPU consuming operation, with non-negligible impact on latency.
            If there is a need to use the same prefix multiple times, consider loadDictionary instead.
-  Note 4 : By default, the prefix is interpreted as raw content (ZSTD_dm_rawContent).
+  Note 4 : By default, the prefix is interpreted as raw content (ZSTD_dct_rawContent).
            Use experimental ZSTD_CCtx_refPrefix_advanced() to alter dictionary interpretation. 
 


 
 
size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
 
  Create an internal DDict from dict buffer,
   to be used to decompress next frames.
   The dictionary remains valid for all future frames, until explicitly invalidated.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Special : Adding a NULL (or 0-size) dictionary invalidates any previous dictionary,
             meaning "return to no-dictionary mode".
   Note 1 : Loading a dictionary involves building tables,
            which has a non-negligible impact on CPU usage and latency.
            It's recommended to "load once, use many times", to amortize the cost
   Note 2 :`dict` content will be copied internally, so `dict` can be released after loading.
            Use ZSTD_DCtx_loadDictionary_byReference() to reference dictionary content instead.
   Note 3 : Use ZSTD_DCtx_loadDictionary_advanced() to take control of
            how dictionary content is loaded and interpreted.
  
 


 
 
size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
 
  Reference a prepared dictionary, to be used to decompress next frames.
   The dictionary remains active for decompression of future frames using same DCtx.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Note 1 : Currently, only one dictionary can be managed.
            Referencing a new dictionary effectively "discards" any previous one.
   Special: referencing a NULL DDict means "return to no-dictionary mode".
   Note 2 : DDict is just referenced, its lifetime must outlive its usage from DCtx.
  
 


 
 
size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx,
                      const void* prefix, size_t prefixSize);
 
  Reference a prefix (single-usage dictionary) to decompress next frame.
   This is the reverse operation of ZSTD_CCtx_refPrefix(),
   and must use the same prefix as the one used during compression.
   Prefix is **only used once**. Reference is discarded at end of frame.
   End of frame is reached when ZSTD_decompressStream() returns 0.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
   Note 1 : Adding any prefix (including NULL) invalidates any previously set prefix or dictionary
   Note 2 : Prefix buffer is referenced. It **must** outlive decompression.
            Prefix buffer must remain unmodified up to the end of frame,
            reached when ZSTD_decompressStream() returns 0.
-  Note 3 : By default, the prefix is treated as raw content (ZSTD_dm_rawContent).
+  Note 3 : By default, the prefix is treated as raw content (ZSTD_dct_rawContent).
            Use ZSTD_CCtx_refPrefix_advanced() to alter dictMode (Experimental section)
   Note 4 : Referencing a raw content prefix has almost no cpu nor memory cost.
            A full dictionary is more costly, as it requires building tables.
  
 


 
 
size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
 size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
 size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
 size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
 size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
 size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
 
  These functions give the _current_ memory usage of selected object.
   Note that object memory usage can evolve (increase or decrease) over time. 
 


 
 
experimental API (static linking only)
  The following symbols and constants
  are not planned to join "stable API" status in the near future.
  They can still change in future versions.
  Some of them are planned to remain in the static_only section indefinitely.
  Some of them might be removed in the future (especially when redundant with existing stable functions)
  
 

 
 
typedef struct {
+    unsigned int matchPos; /* Match pos in dst */
+    /* If seqDef.offset > 3, then this is seqDef.offset - 3
+     * If seqDef.offset < 3, then this is the corresponding repeat offset
+     * But if seqDef.offset < 3 and litLength == 0, this is the
+     *   repeat offset before the corresponding repeat offset
+     * And if seqDef.offset == 3 and litLength == 0, this is the
+     *   most recent repeat offset - 1
+     */
+    unsigned int offset;
+    unsigned int litLength; /* Literal length */
+    unsigned int matchLength; /* Match length */
+    /* 0 when seq not rep and seqDef.offset otherwise
+     * when litLength == 0 this will be <= 4, otherwise <= 3 like normal
+     */
+    unsigned int rep;
+} ZSTD_Sequence;
+


+
typedef struct {
     unsigned windowLog;       /**< largest match distance : larger == more compression, more memory needed during decompression */
     unsigned chainLog;        /**< fully searched segment : larger == more compression, slower, more memory (useless for fast) */
     unsigned hashLog;         /**< dispatch table : larger == faster, more memory */
     unsigned searchLog;       /**< nb of searches : larger == more compression, slower */
     unsigned minMatch;        /**< match length searched : larger == faster decompression, sometimes less compression */
     unsigned targetLength;    /**< acceptable match size for optimal parser (only) : larger == more compression, slower */
     ZSTD_strategy strategy;   /**< see ZSTD_strategy definition above */
 } ZSTD_compressionParameters;
 


 
typedef struct {
     int contentSizeFlag; /**< 1: content size will be in frame header (when known) */
     int checksumFlag;    /**< 1: generate a 32-bits checksum using XXH64 algorithm at end of frame, for error detection */
     int noDictIDFlag;    /**< 1: no dictID will be saved into frame header (dictID is only useful for dictionary compression) */
 } ZSTD_frameParameters;
 


 
typedef struct {
     ZSTD_compressionParameters cParams;
     ZSTD_frameParameters fParams;
 } ZSTD_parameters;
 


 
typedef enum {
     ZSTD_dct_auto = 0,       /* dictionary is "full" when starting with ZSTD_MAGIC_DICTIONARY, otherwise it is "rawContent" */
     ZSTD_dct_rawContent = 1, /* ensures dictionary is always loaded as rawContent, even if it starts with ZSTD_MAGIC_DICTIONARY */
     ZSTD_dct_fullDict = 2    /* refuses to load a dictionary if it does not respect Zstandard's specification, starting with ZSTD_MAGIC_DICTIONARY */
 } ZSTD_dictContentType_e;
 


 
typedef enum {
     ZSTD_dlm_byCopy = 0,  /**< Copy dictionary content internally */
-    ZSTD_dlm_byRef = 1,   /**< Reference dictionary content -- the dictionary buffer must outlive its users. */
+    ZSTD_dlm_byRef = 1    /**< Reference dictionary content -- the dictionary buffer must outlive its users. */
 } ZSTD_dictLoadMethod_e;
 


 
typedef enum {
-    /* Opened question : should we have a format ZSTD_f_auto ?
-     * Today, it would mean exactly the same as ZSTD_f_zstd1.
-     * But, in the future, should several formats become supported,
-     * on the compression side, it would mean "default format".
-     * On the decompression side, it would mean "automatic format detection",
-     * so that ZSTD_f_zstd1 would mean "accept *only* zstd frames".
-     * Since meaning is a little different, another option could be to define different enums for compression and decompression.
-     * This question could be kept for later, when there are actually multiple formats to support,
-     * but there is also the question of pinning enum values, and pinning value `0` is especially important */
     ZSTD_f_zstd1 = 0,           /* zstd frame format, specified in zstd_compression_format.md (default) */
-    ZSTD_f_zstd1_magicless = 1, /* Variant of zstd frame format, without initial 4-bytes magic number.
+    ZSTD_f_zstd1_magicless = 1  /* Variant of zstd frame format, without initial 4-bytes magic number.
                                  * Useful to save 4 bytes per generated frame.
                                  * Decoder cannot recognise automatically this format, requiring this instruction. */
 } ZSTD_format_e;
 


 
typedef enum {
     /* Note: this enum and the behavior it controls are effectively internal
      * implementation details of the compressor. They are expected to continue
      * to evolve and should be considered only in the context of extremely
      * advanced performance tuning.
      *
-     * Zstd currently supports the use of a CDict in two ways:
+     * Zstd currently supports the use of a CDict in three ways:
      *
      * - The contents of the CDict can be copied into the working context. This
      *   means that the compression can search both the dictionary and input
      *   while operating on a single set of internal tables. This makes
      *   the compression faster per-byte of input. However, the initial copy of
      *   the CDict's tables incurs a fixed cost at the beginning of the
      *   compression. For small compressions (< 8 KB), that copy can dominate
      *   the cost of the compression.
      *
      * - The CDict's tables can be used in-place. In this model, compression is
      *   slower per input byte, because the compressor has to search two sets of
      *   tables. However, this model incurs no start-up cost (as long as the
      *   working context's tables can be reused). For small inputs, this can be
      *   faster than copying the CDict's tables.
      *
+     * - The CDict's tables are not used at all, and instead we use the working
+     *   context alone to reload the dictionary and use params based on the source
+     *   size. See ZSTD_compress_insertDictionary() and ZSTD_compress_usingDict().
+     *   This method is effective when the dictionary sizes are very small relative
+     *   to the input size, and the input size is fairly large to begin with.
+     *
      * Zstd has a simple internal heuristic that selects which strategy to use
      * at the beginning of a compression. However, if experimentation shows that
      * Zstd is making poor choices, it is possible to override that choice with
      * this enum.
      */
     ZSTD_dictDefaultAttach = 0, /* Use the default heuristic. */
     ZSTD_dictForceAttach   = 1, /* Never copy the dictionary. */
     ZSTD_dictForceCopy     = 2, /* Always copy the dictionary. */
+    ZSTD_dictForceLoad     = 3  /* Always reload the dictionary */
 } ZSTD_dictAttachPref_e;
 


 
typedef enum {
   ZSTD_lcm_auto = 0,          /**< Automatically determine the compression mode based on the compression level.
                                *   Negative compression levels will be uncompressed, and positive compression
                                *   levels will be compressed. */
   ZSTD_lcm_huffman = 1,       /**< Always attempt Huffman compression. Uncompressed literals will still be
                                *   emitted if Huffman compression is not profitable. */
-  ZSTD_lcm_uncompressed = 2,  /**< Always emit uncompressed literals. */
+  ZSTD_lcm_uncompressed = 2   /**< Always emit uncompressed literals. */
 } ZSTD_literalCompressionMode_e;
 


 
Frame size functions

 
 
unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize);
 
  `src` should point to the start of a series of ZSTD encoded and/or skippable frames
   `srcSize` must be the _exact_ size of this series
        (i.e. there should be a frame boundary at `src + srcSize`)
   @return : - decompressed size of all data in all successive frames
             - if the decompressed size cannot be determined: ZSTD_CONTENTSIZE_UNKNOWN
             - if an error occurred: ZSTD_CONTENTSIZE_ERROR
 
    note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
             When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
             In which case, it's necessary to use streaming mode to decompress data.
    note 2 : decompressed size is always present when compression is done with ZSTD_compress()
    note 3 : decompressed size can be very large (64-bits value),
             potentially larger than what local system can handle as a single memory segment.
             In which case, it's necessary to use streaming mode to decompress data.
    note 4 : If source is untrusted, decompressed size could be wrong or intentionally modified.
             Always ensure result fits within application's authorized limits.
             Each application can set its own limits.
    note 5 : ZSTD_findDecompressedSize handles multiple frames, and so it must traverse the input to
             read each contained frame header.  This is fast as most of the data is skipped,
             however it does mean that all frame data must be present and valid. 
 


 
 
unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize);
 
  `src` should point to the start of a series of ZSTD encoded and/or skippable frames
   `srcSize` must be the _exact_ size of this series
        (i.e. there should be a frame boundary at `src + srcSize`)
   @return : - upper-bound for the decompressed size of all data in all successive frames
             - if an error occured: ZSTD_CONTENTSIZE_ERROR
 
   note 1  : an error can occur if `src` contains an invalid or incorrectly formatted frame.
   note 2  : the upper-bound is exact when the decompressed size field is available in every ZSTD encoded frame of `src`.
             in this case, `ZSTD_findDecompressedSize` and `ZSTD_decompressBound` return the same value.
   note 3  : when the decompressed size field isn't available, the upper-bound for that frame is calculated by:
               upper-bound = # blocks * min(128 KB, Window_Size)
  
 


 
 
size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
 
  srcSize must be >= ZSTD_FRAMEHEADERSIZE_PREFIX.
  @return : size of the Frame Header,
            or an error code (if srcSize is too small) 
 


 
+
size_t ZSTD_getSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
+    size_t outSeqsSize, const void* src, size_t srcSize);
+
 Extract sequences from the sequence store
+ zc can be used to insert custom compression params.
+ This function invokes ZSTD_compress2
+ @return : number of sequences extracted
+ 
+


+
 
Memory management

 
 
size_t ZSTD_estimateCCtxSize(int compressionLevel);
 size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams);
 size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params);
 size_t ZSTD_estimateDCtxSize(void);
-
  These functions make it possible to estimate memory usage
-  of a future {D,C}Ctx, before its creation.
-  ZSTD_estimateCCtxSize() will provide a budget large enough for any compression level up to selected one.
-  It will also consider src size to be arbitrarily "large", which is worst case.
-  If srcSize is known to always be small, ZSTD_estimateCCtxSize_usingCParams() can provide a tighter estimation.
-  ZSTD_estimateCCtxSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
-  ZSTD_estimateCCtxSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParams_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_c_nbWorkers is >= 1.
-  Note : CCtx size estimation is only correct for single-threaded compression. 
+
  These functions make it possible to estimate memory usage of a future
+  {D,C}Ctx, before its creation.
+
+  ZSTD_estimateCCtxSize() will provide a budget large enough for any
+  compression level up to selected one. Unlike ZSTD_estimateCStreamSize*(),
+  this estimate does not include space for a window buffer, so this estimate
+  is guaranteed to be enough for single-shot compressions, but not streaming
+  compressions. It will however assume the input may be arbitrarily large,
+  which is the worst case. If srcSize is known to always be small,
+  ZSTD_estimateCCtxSize_usingCParams() can provide a tighter estimation.
+  ZSTD_estimateCCtxSize_usingCParams() can be used in tandem with
+  ZSTD_getCParams() to create cParams from compressionLevel.
+  ZSTD_estimateCCtxSize_usingCCtxParams() can be used in tandem with
+  ZSTD_CCtxParams_setParameter().
+
+  Note: only single-threaded compression is supported. This function will
+  return an error code if ZSTD_c_nbWorkers is >= 1. 
 


 
 
size_t ZSTD_estimateCStreamSize(int compressionLevel);
 size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams);
 size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params);
 size_t ZSTD_estimateDStreamSize(size_t windowSize);
 size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize);
 
  ZSTD_estimateCStreamSize() will provide a budget large enough for any compression level up to selected one.
   It will also consider src size to be arbitrarily "large", which is worst case.
   If srcSize is known to always be small, ZSTD_estimateCStreamSize_usingCParams() can provide a tighter estimation.
   ZSTD_estimateCStreamSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
   ZSTD_estimateCStreamSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParams_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_c_nbWorkers is >= 1.
   Note : CStream size estimation is only correct for single-threaded compression.
   ZSTD_DStream memory budget depends on window Size.
   This information can be passed manually, using ZSTD_estimateDStreamSize,
   or deducted from a valid frame Header, using ZSTD_estimateDStreamSize_fromFrame();
   Note : if streaming is init with function ZSTD_init?Stream_usingDict(),
          an internal ?Dict will be created, which additional size is not estimated here.
          In this case, get total size by adding ZSTD_estimate?DictSize 
 


 
 
size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel);
 size_t ZSTD_estimateCDictSize_advanced(size_t dictSize, ZSTD_compressionParameters cParams, ZSTD_dictLoadMethod_e dictLoadMethod);
 size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod);
 
  ZSTD_estimateCDictSize() will bet that src size is relatively "small", and content is copied, like ZSTD_createCDict().
   ZSTD_estimateCDictSize_advanced() makes it possible to control compression parameters precisely, like ZSTD_createCDict_advanced().
   Note : dictionaries created by reference (`ZSTD_dlm_byRef`) are logically smaller.
  
 


 
 
ZSTD_CCtx*    ZSTD_initStaticCCtx(void* workspace, size_t workspaceSize);
 ZSTD_CStream* ZSTD_initStaticCStream(void* workspace, size_t workspaceSize);    /**< same as ZSTD_initStaticCCtx() */
 
  Initialize an object using a pre-allocated fixed-size buffer.
   workspace: The memory area to emplace the object into.
              Provided pointer *must be 8-bytes aligned*.
              Buffer must outlive object.
   workspaceSize: Use ZSTD_estimate*Size() to determine
                  how large workspace must be to support target scenario.
  @return : pointer to object (same address as workspace, just different type),
            or NULL if error (size too small, incorrect alignment, etc.)
   Note : zstd will never resize nor malloc() when using a static buffer.
          If the object requires more memory than available,
          zstd will just error out (typically ZSTD_error_memory_allocation).
   Note 2 : there is no corresponding "free" function.
            Since workspace is allocated externally, it must be freed externally too.
   Note 3 : cParams : use ZSTD_getCParams() to convert a compression level
            into its associated cParams.
   Limitation 1 : currently not compatible with internal dictionary creation, triggered by
                  ZSTD_CCtx_loadDictionary(), ZSTD_initCStream_usingDict() or ZSTD_initDStream_usingDict().
   Limitation 2 : static cctx currently not compatible with multi-threading.
   Limitation 3 : static dctx is incompatible with legacy support.
  
 


 
 
ZSTD_DStream* ZSTD_initStaticDStream(void* workspace, size_t workspaceSize);    /**< same as ZSTD_initStaticDCtx() */
 


 
typedef void* (*ZSTD_allocFunction) (void* opaque, size_t size);
 typedef void  (*ZSTD_freeFunction) (void* opaque, void* address);
 typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; void* opaque; } ZSTD_customMem;
 static ZSTD_customMem const ZSTD_defaultCMem = { NULL, NULL, NULL };  /**< this constant defers to stdlib's functions */
 
  These prototypes make it possible to pass your own allocation/free functions.
   ZSTD_customMem is provided at creation time, using ZSTD_create*_advanced() variants listed below.
   All allocation/free operations will be completed using these custom variants instead of regular  ones.
  
 


 
 
Advanced compression functions

 
 
ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel);
 
  Create a digested dictionary for compression
   Dictionary content is just referenced, not duplicated.
   As a consequence, `dictBuffer` **must** outlive CDict,
-  and its content must remain unmodified throughout the lifetime of CDict. 
+  and its content must remain unmodified throughout the lifetime of CDict.
+  note: equivalent to ZSTD_createCDict_advanced(), with dictLoadMethod==ZSTD_dlm_byRef 
 


 
 
ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
 
 @return ZSTD_compressionParameters structure for a selected compression level and estimated srcSize.
  `estimatedSrcSize` value is optional, select 0 if not known 
 


 
 
ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
 
  same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of sub-component `ZSTD_compressionParameters`.
   All fields of `ZSTD_frameParameters` are set to default : contentSize=1, checksum=0, noDictID=0 
 


 
 
size_t ZSTD_checkCParams(ZSTD_compressionParameters params);
 
  Ensure param values remain within authorized range.
  @return 0 on success, or an error code (can be checked with ZSTD_isError()) 
 


 
 
ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);
 
  optimize params for a given `srcSize` and `dictSize`.
  `srcSize` can be unknown, in which case use ZSTD_CONTENTSIZE_UNKNOWN.
  `dictSize` must be `0` when there is no dictionary.
   cPar can be invalid : all parameters will be clamped within valid range in the @return struct.
   This function never fails (wide contract) 
 


 
 
size_t ZSTD_compress_advanced(ZSTD_CCtx* cctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize,
                         const void* dict,size_t dictSize,
                               ZSTD_parameters params);
-
  Same as ZSTD_compress_usingDict(), with fine-tune control over compression parameters (by structure) 
+
  Note : this function is now DEPRECATED.
+         It can be replaced by ZSTD_compress2(), in combination with ZSTD_CCtx_setParameter() and other parameter setters.
+  This prototype will be marked as deprecated and generate compilation warning on reaching v1.5.x 
 


 
 
size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
                                   void* dst, size_t dstCapacity,
                             const void* src, size_t srcSize,
                             const ZSTD_CDict* cdict,
                                   ZSTD_frameParameters fParams);
-
  Same as ZSTD_compress_usingCDict(), with fine-tune control over frame parameters 
+
  Note : this function is now REDUNDANT.
+         It can be replaced by ZSTD_compress2(), in combination with ZSTD_CCtx_loadDictionary() and other parameter setters.
+  This prototype will be marked as deprecated and generate compilation warning in some future version 
 


 
 
size_t ZSTD_CCtx_loadDictionary_byReference(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
 
  Same as ZSTD_CCtx_loadDictionary(), but dictionary content is referenced, instead of being copied into CCtx.
   It saves some memory, but also requires that `dict` outlives its usage within `cctx` 
 


 
 
size_t ZSTD_CCtx_loadDictionary_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);
 
  Same as ZSTD_CCtx_loadDictionary(), but gives finer control over
   how to load the dictionary (by copy ? by reference ?)
   and how to interpret it (automatic ? force raw mode ? full mode only ?) 
 


 
 
size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
 
  Same as ZSTD_CCtx_refPrefix(), but gives finer control over
   how to interpret prefix content (automatic ? force raw mode (default) ? full mode only ?) 
 


 
 
size_t ZSTD_CCtx_getParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int* value);
 
  Get the requested compression parameter value, selected by enum ZSTD_cParameter,
   and store it into int* value.
  @return : 0, or an error code (which can be tested with ZSTD_isError()).
  
 


 
 
ZSTD_CCtx_params* ZSTD_createCCtxParams(void);
 size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params);
 
  Quick howto :
   - ZSTD_createCCtxParams() : Create a ZSTD_CCtx_params structure
   - ZSTD_CCtxParams_setParameter() : Push parameters one by one into
                                      an existing ZSTD_CCtx_params structure.
                                      This is similar to
                                      ZSTD_CCtx_setParameter().
   - ZSTD_CCtx_setParametersUsingCCtxParams() : Apply parameters to
                                     an existing CCtx.
                                     These parameters will be applied to
                                     all subsequent frames.
   - ZSTD_compressStream2() : Do compression using the CCtx.
   - ZSTD_freeCCtxParams() : Free the memory.
 
   This can be used with ZSTD_estimateCCtxSize_advanced_usingCCtxParams()
   for static allocation of CCtx for single-threaded compression.
  
 


 
 
size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params);
 
  Reset params to default values.
  
 


 
 
size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel);
 
  Initializes the compression parameters of cctxParams according to
   compression level. All other parameters are reset to their default values.
  
 


 
 
size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params);
 
  Initializes the compression and frame parameters of cctxParams according to
   params. All other parameters are reset to their default values.
  
 


 
 
size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int value);
 
  Similar to ZSTD_CCtx_setParameter.
   Set one compression parameter, selected by enum ZSTD_cParameter.
   Parameters must be applied to a ZSTD_CCtx using ZSTD_CCtx_setParametersUsingCCtxParams().
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
  
 


 
 
size_t ZSTD_CCtxParams_getParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int* value);
 
 Similar to ZSTD_CCtx_getParameter.
  Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
  @result : 0, or an error code (which can be tested with ZSTD_isError()).
  
 


 
 
size_t ZSTD_CCtx_setParametersUsingCCtxParams(
         ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params);
 
  Apply a set of ZSTD_CCtx_params to the compression context.
   This can be done even after compression is started,
     if nbWorkers==0, this will have no impact until a new compression is started.
     if nbWorkers>=1, new parameters will be picked up at next job,
        with a few restrictions (windowLog, pledgedSrcSize, nbWorkers, jobSize, and overlapLog are not updated).
  
 


 
 
size_t ZSTD_compressStream2_simpleArgs (
                 ZSTD_CCtx* cctx,
                 void* dst, size_t dstCapacity, size_t* dstPos,
           const void* src, size_t srcSize, size_t* srcPos,
                 ZSTD_EndDirective endOp);
 
  Same as ZSTD_compressStream2(),
   but using only integral types as arguments.
   This variant might be helpful for binders from dynamic languages
   which have troubles handling structures containing memory pointers.
  
 


 
 
Advanced decompression functions

 
 
unsigned ZSTD_isFrame(const void* buffer, size_t size);
 
  Tells if the content of `buffer` starts with a valid Frame Identifier.
   Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
   Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
   Note 3 : Skippable Frame Identifiers are considered valid. 
 


 
 
ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize);
 
  Create a digested dictionary, ready to start decompression operation without startup delay.
   Dictionary content is referenced, and therefore stays in dictBuffer.
   It is important that dictBuffer outlives DDict,
   it must remain read accessible throughout the lifetime of DDict 
 


 
 
size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
 
  Same as ZSTD_DCtx_loadDictionary(),
   but references `dict` content instead of copying it into `dctx`.
   This saves memory if `dict` remains around.,
   However, it's imperative that `dict` remains accessible (and unmodified) while being used, so it must outlive decompression. 
 


 
 
size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);
 
  Same as ZSTD_DCtx_loadDictionary(),
   but gives direct control over
   how to load the dictionary (by copy ? by reference ?)
   and how to interpret it (automatic ? force raw mode ? full mode only ?). 
 


 
 
size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
 
  Same as ZSTD_DCtx_refPrefix(), but gives finer control over
   how to interpret prefix content (automatic ? force raw mode (default) ? full mode only ?) 
 


 
 
size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize);
 
  Refuses allocating internal buffers for frames requiring a window size larger than provided limit.
   This protects a decoder context from reserving too much memory for itself (potential attack scenario).
   This parameter is only useful in streaming mode, since no internal buffer is allocated in single-pass mode.
   By default, a decompression context accepts all window sizes <= (1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT)
  @return : 0, or an error code (which can be tested using ZSTD_isError()).
  
 


 
 
size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format);
 
  Instruct the decoder context about what kind of data to decode next.
   This instruction is mandatory to decode data without a fully-formed header,
   such ZSTD_f_zstd1_magicless for example.
  @return : 0, or an error code (which can be tested using ZSTD_isError()). 
 


 
 
size_t ZSTD_decompressStream_simpleArgs (
                 ZSTD_DCtx* dctx,
                 void* dst, size_t dstCapacity, size_t* dstPos,
           const void* src, size_t srcSize, size_t* srcPos);
 
  Same as ZSTD_decompressStream(),
   but using only integral types as arguments.
   This can be helpful for binders from dynamic languages
   which have troubles handling structures containing memory pointers.
  
 


 
 
Advanced streaming functions
  Warning : most of these functions are now redundant with the Advanced API.
   Once Advanced API reaches "stable" status,
   redundant functions will be deprecated, and then at some point removed.
 

 
 
Advanced Streaming compression functions
/**! ZSTD_initCStream_srcSize() :
  * This function is deprecated, and equivalent to:
  *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
  *     ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any)
  *     ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
  *     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
  *
  * pledgedSrcSize must be correct. If it is not known at init time, use
  * ZSTD_CONTENTSIZE_UNKNOWN. Note that, for compatibility with older programs,
  * "0" also disables frame content size field. It may be enabled in the future.
+ * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
  */
-size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize);
-/**! ZSTD_initCStream_usingDict() :
- * This function is deprecated, and is equivalent to:
- *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
- *     ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
- *     ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
- *
- * Creates of an internal CDict (incompatible with static CCtx), except if
- * dict == NULL or dictSize < 8, in which case no dict is used.
- * Note: dict is loaded with ZSTD_dm_auto (treated as a full zstd dictionary if
- * it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.
- */
-size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel);
-/**! ZSTD_initCStream_advanced() :
- * This function is deprecated, and is approximately equivalent to:
- *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
- *     ZSTD_CCtx_setZstdParams(zcs, params); // Set the zstd params and leave the rest as-is
- *     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
- *     ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
- *
- * pledgedSrcSize must be correct. If srcSize is not known at init time, use
- * value ZSTD_CONTENTSIZE_UNKNOWN. dict is loaded with ZSTD_dm_auto and ZSTD_dlm_byCopy.
- */
-size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs, const void* dict, size_t dictSize,
-                                             ZSTD_parameters params, unsigned long long pledgedSrcSize);
-/**! ZSTD_initCStream_usingCDict() :
- * This function is deprecated, and equivalent to:
- *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
- *     ZSTD_CCtx_refCDict(zcs, cdict);
- *
- * note : cdict will just be referenced, and must outlive compression session
- */
-size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);
-/**! ZSTD_initCStream_usingCDict_advanced() :
- * This function is deprecated, and is approximately equivalent to:
- *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
- *     ZSTD_CCtx_setZstdFrameParams(zcs, fParams); // Set the zstd frame params and leave the rest as-is
- *     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
- *     ZSTD_CCtx_refCDict(zcs, cdict);
- *
- * same as ZSTD_initCStream_usingCDict(), with control over frame parameters.
- * pledgedSrcSize must be correct. If srcSize is not known at init time, use
- * value ZSTD_CONTENTSIZE_UNKNOWN.
- */
-size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs, const ZSTD_CDict* cdict, ZSTD_frameParameters fParams, unsigned long long pledgedSrcSize);
+size_t
+ZSTD_initCStream_srcSize(ZSTD_CStream* zcs,
+                         int compressionLevel,
+                         unsigned long long pledgedSrcSize);
 


+
! ZSTD_initCStream_usingDict() :
 This function is deprecated, and is equivalent to:
+     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+     ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
+     ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
+
+ Creates of an internal CDict (incompatible with static CCtx), except if
+ dict == NULL or dictSize < 8, in which case no dict is used.
+ Note: dict is loaded with ZSTD_dct_auto (treated as a full zstd dictionary if
+ it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.
+ Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
+ 
+

+
+
! ZSTD_initCStream_advanced() :
 This function is deprecated, and is approximately equivalent to:
+     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+     // Pseudocode: Set each zstd parameter and leave the rest as-is.
+     for ((param, value) : params) {
+         ZSTD_CCtx_setParameter(zcs, param, value);
+     }
+     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+     ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
+
+ dict is loaded with ZSTD_dct_auto and ZSTD_dlm_byCopy.
+ pledgedSrcSize must be correct.
+ If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN.
+ Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
+ 
+

+
+
! ZSTD_initCStream_usingCDict() :
 This function is deprecated, and equivalent to:
+     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+     ZSTD_CCtx_refCDict(zcs, cdict);
+
+ note : cdict will just be referenced, and must outlive compression session
+ Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
+ 
+

+
+
! ZSTD_initCStream_usingCDict_advanced() :
   This function is DEPRECATED, and is approximately equivalent to:
+     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
+     // Pseudocode: Set each zstd frame parameter and leave the rest as-is.
+     for ((fParam, value) : fParams) {
+         ZSTD_CCtx_setParameter(zcs, fParam, value);
+     }
+     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
+     ZSTD_CCtx_refCDict(zcs, cdict);
+
+ same as ZSTD_initCStream_usingCDict(), with control over frame parameters.
+ pledgedSrcSize must be correct. If srcSize is not known at init time, use
+ value ZSTD_CONTENTSIZE_UNKNOWN.
+ Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
+ 
+

+
 
size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize);
 
 This function is deprecated, and is equivalent to:
      ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
      ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
 
   start a new frame, using same parameters from previous frame.
   This is typically useful to skip dictionary loading stage, since it will re-use it in-place.
   Note that zcs must be init at least once before using ZSTD_resetCStream().
   If pledgedSrcSize is not known at reset time, use macro ZSTD_CONTENTSIZE_UNKNOWN.
   If pledgedSrcSize > 0, its value must be correct, as it will be written in header, and controlled at the end.
   For the time being, pledgedSrcSize==0 is interpreted as "srcSize unknown" for compatibility with older programs,
   but it will change to mean "empty" in future version, so use macro ZSTD_CONTENTSIZE_UNKNOWN instead.
  @return : 0, or an error code (which can be tested using ZSTD_isError())
+  Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
  
 


 
 
typedef struct {
     unsigned long long ingested;   /* nb input bytes read and buffered */
     unsigned long long consumed;   /* nb input bytes actually compressed */
     unsigned long long produced;   /* nb of compressed bytes generated and buffered */
     unsigned long long flushed;    /* nb of compressed bytes flushed : not provided; can be tracked from caller side */
     unsigned currentJobID;         /* MT only : latest started job nb */
     unsigned nbActiveWorkers;      /* MT only : nb of workers actively compressing at probe time */
 } ZSTD_frameProgression;
 


 
size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx);
 
  Tell how many bytes are ready to be flushed immediately.
   Useful for multithreading scenarios (nbWorkers >= 1).
   Probe the oldest active job, defined as oldest job not yet entirely flushed,
   and check its output buffer.
  @return : amount of data stored in oldest job and ready to be flushed immediately.
   if @return == 0, it means either :
   + there is no active job (could be checked with ZSTD_frameProgression()), or
   + oldest job is still actively compressing data,
     but everything it has produced has also been flushed so far,
     therefore flush speed is limited by production speed of oldest job
     irrespective of the speed of concurrent (and newer) jobs.
  
 


 
 
Advanced Streaming decompression functions
/**
  * This function is deprecated, and is equivalent to:
  *
  *     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
  *     ZSTD_DCtx_loadDictionary(zds, dict, dictSize);
  *
  * note: no dictionary will be used if dict == NULL or dictSize < 8
+ * Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
  */
 size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize);
-/**
- * This function is deprecated, and is equivalent to:
- *
- *     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
- *     ZSTD_DCtx_refDDict(zds, ddict);
- *
- * note : ddict is referenced, it must outlive decompression session
- */
-size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);
-/**
- * This function is deprecated, and is equivalent to:
- *
- *     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
- *
- * re-use decompression parameters from previous init; saves dictionary loading
- */
-size_t ZSTD_resetDStream(ZSTD_DStream* zds);
 


-
Buffer-less and synchronous inner streaming functions
+
This function is deprecated, and is equivalent to:
+     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+     ZSTD_DCtx_refDDict(zds, ddict);
+
+ note : ddict is referenced, it must outlive decompression session
+ Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
+ 
+

+
+
This function is deprecated, and is equivalent to:
+     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
+
+ re-use decompression parameters from previous init; saves dictionary loading
+ Note : this prototype will be marked as deprecated and generate compilation warnings on reaching v1.5.x
+ 
+

+
+
Buffer-less and synchronous inner streaming functions
   This is an advanced API, giving full control over buffer management, for users which need direct control over memory.
   But it's also a complex one, with several restrictions, documented below.
   Prefer normal streaming API for an easier experience.
  
 

 
-
Buffer-less streaming compression (synchronous mode)
+
Buffer-less streaming compression (synchronous mode)
   A ZSTD_CCtx object is required to track streaming operations.
   Use ZSTD_createCCtx() / ZSTD_freeCCtx() to manage resource.
   ZSTD_CCtx object can be re-used multiple times within successive compression operations.
 
   Start by initializing a context.
   Use ZSTD_compressBegin(), or ZSTD_compressBegin_usingDict() for dictionary compression,
   or ZSTD_compressBegin_advanced(), for finer parameter control.
   It's also possible to duplicate a reference context which has already been initialized, using ZSTD_copyCCtx()
 
   Then, consume your input using ZSTD_compressContinue().
   There are some important considerations to keep in mind when using this advanced function :
   - ZSTD_compressContinue() has no internal buffer. It uses externally provided buffers only.
   - Interface is synchronous : input is consumed entirely and produces 1+ compressed blocks.
   - Caller must ensure there is enough space in `dst` to store compressed data under worst case scenario.
     Worst case evaluation is provided by ZSTD_compressBound().
     ZSTD_compressContinue() doesn't guarantee recover after a failed compression.
   - ZSTD_compressContinue() presumes prior input ***is still accessible and unmodified*** (up to maximum distance size, see WindowLog).
     It remembers all previous contiguous blocks, plus one separated memory segment (which can itself consists of multiple contiguous blocks)
   - ZSTD_compressContinue() detects that prior input has been overwritten when `src` buffer overlaps.
     In which case, it will "discard" the relevant memory section from its history.
 
   Finish a frame with ZSTD_compressEnd(), which will write the last block(s) and optional checksum.
   It's possible to use srcSize==0, in which case, it will write a final empty block to end the frame.
   Without last block mark, frames are considered unfinished (hence corrupted) by compliant decoders.
 
   `ZSTD_CCtx` object can be re-used (ZSTD_compressBegin()) to compress again.
 

 
 
Buffer-less streaming compression functions
size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
 size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
 size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize : If srcSize is not known at init time, use ZSTD_CONTENTSIZE_UNKNOWN */
 size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict); /**< note: fails if cdict==NULL */
 size_t ZSTD_compressBegin_usingCDict_advanced(ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict, ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize);   /* compression parameters are already set within cdict. pledgedSrcSize must be correct. If srcSize is not known, use macro ZSTD_CONTENTSIZE_UNKNOWN */
 size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize); /**<  note: if pledgedSrcSize is not known, use ZSTD_CONTENTSIZE_UNKNOWN */
 


-
Buffer-less streaming decompression (synchronous mode)
+
Buffer-less streaming decompression (synchronous mode)
   A ZSTD_DCtx object is required to track streaming operations.
   Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it.
   A ZSTD_DCtx object can be re-used multiple times.
 
   First typical operation is to retrieve frame parameters, using ZSTD_getFrameHeader().
   Frame header is extracted from the beginning of compressed frame, so providing only the frame's beginning is enough.
   Data fragment must be large enough to ensure successful decoding.
  `ZSTD_frameHeaderSize_max` bytes is guaranteed to always be large enough.
   @result : 0 : successful decoding, the `ZSTD_frameHeader` structure is correctly filled.
            >0 : `srcSize` is too small, please provide at least @result bytes on next attempt.
            errorCode, which can be tested using ZSTD_isError().
 
   It fills a ZSTD_frameHeader structure with important information to correctly decode the frame,
   such as the dictionary ID, content size, or maximum back-reference distance (`windowSize`).
   Note that these values could be wrong, either because of data corruption, or because a 3rd party deliberately spoofs false information.
   As a consequence, check that values remain within valid application range.
   For example, do not allocate memory blindly, check that `windowSize` is within expectation.
   Each application can set its own limits, depending on local restrictions.
   For extended interoperability, it is recommended to support `windowSize` of at least 8 MB.
 
   ZSTD_decompressContinue() needs previous data blocks during decompression, up to `windowSize` bytes.
   ZSTD_decompressContinue() is very sensitive to contiguity,
   if 2 blocks don't follow each other, make sure that either the compressor breaks contiguity at the same place,
   or that previous contiguous segment is large enough to properly handle maximum back-reference distance.
   There are multiple ways to guarantee this condition.
 
   The most memory efficient way is to use a round buffer of sufficient size.
   Sufficient size is determined by invoking ZSTD_decodingBufferSize_min(),
   which can @return an error code if required value is too large for current system (in 32-bits mode).
   In a round buffer methodology, ZSTD_decompressContinue() decompresses each block next to previous one,
   up to the moment there is not enough room left in the buffer to guarantee decoding another full block,
   which maximum size is provided in `ZSTD_frameHeader` structure, field `blockSizeMax`.
   At which point, decoding can resume from the beginning of the buffer.
   Note that already decoded data stored in the buffer should be flushed before being overwritten.
 
   There are alternatives possible, for example using two or more buffers of size `windowSize` each, though they consume more memory.
 
   Finally, if you control the compression process, you can also ignore all buffer size rules,
   as long as the encoder and decoder progress in "lock-step",
   aka use exactly the same buffer sizes, break contiguity at the same place, etc.
 
   Once buffers are setup, start decompression, with ZSTD_decompressBegin().
   If decompression requires a dictionary, use ZSTD_decompressBegin_usingDict() or ZSTD_decompressBegin_usingDDict().
 
   Then use ZSTD_nextSrcSizeToDecompress() and ZSTD_decompressContinue() alternatively.
   ZSTD_nextSrcSizeToDecompress() tells how many bytes to provide as 'srcSize' to ZSTD_decompressContinue().
   ZSTD_decompressContinue() requires this _exact_ amount of bytes, or it will fail.
 
  @result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst' (necessarily <= dstCapacity).
   It can be zero : it just means ZSTD_decompressContinue() has decoded some metadata item.
   It can also be an error code, which can be tested with ZSTD_isError().
 
   A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
   Context can then be reset to start a new decompression.
 
   Note : it's possible to know if next input to present is a header or a block, using ZSTD_nextInputType().
   This information is not required to properly decode a frame.
 
   == Special case : skippable frames 
 
   Skippable frames allow integration of user-defined data into a flow of concatenated frames.
   Skippable frames will be ignored (skipped) by decompressor.
   The format of skippable frames is as follows :
   a) Skippable frame ID - 4 Bytes, Little endian format, any value from 0x184D2A50 to 0x184D2A5F
   b) Frame Size - 4 Bytes, Little endian format, unsigned 32-bits
   c) Frame Content - any content (User Data) of length equal to Frame Size
   For skippable frames ZSTD_getFrameHeader() returns zfhPtr->frameType==ZSTD_skippableFrame.
   For skippable frames ZSTD_decompressContinue() always returns 0 : it only skips the content.
 

 
 
Buffer-less streaming decompression functions
typedef enum { ZSTD_frame, ZSTD_skippableFrame } ZSTD_frameType_e;
 typedef struct {
     unsigned long long frameContentSize; /* if == ZSTD_CONTENTSIZE_UNKNOWN, it means this field is not available. 0 means "empty" */
     unsigned long long windowSize;       /* can be very large, up to <= frameContentSize */
     unsigned blockSizeMax;
     ZSTD_frameType_e frameType;          /* if == ZSTD_skippableFrame, frameContentSize is the size of skippable content */
     unsigned headerSize;
     unsigned dictID;
     unsigned checksumFlag;
 } ZSTD_frameHeader;
 


 
size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize);   /**< doesn't consume input */
 /*! ZSTD_getFrameHeader_advanced() :
  *  same as ZSTD_getFrameHeader(),
  *  with added capability to select a format (like ZSTD_f_zstd1_magicless) */
 size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format);
 size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize);  /**< when frame content size is not known, pass in frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN */
 
  decode Frame Header, or requires larger `srcSize`.
  @return : 0, `zfhPtr` is correctly filled,
           >0, `srcSize` is too small, value is wanted `srcSize` amount,
            or an error code, which can be tested using ZSTD_isError() 
 


 
 
typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
 


-
Block level API

+
Block level API

 
-
    Frame metadata cost is typically ~18 bytes, which can be non-negligible for very small blocks (< 100 bytes).
-    User will have to take in charge required information to regenerate data, such as compressed and content sizes.
+
    Frame metadata cost is typically ~12 bytes, which can be non-negligible for very small blocks (< 100 bytes).
+    But users will have to take in charge needed metadata to regenerate data, such as compressed and content sizes.
 
     A few rules to respect :
     - Compressing and decompressing require a context structure
       + Use ZSTD_createCCtx() and ZSTD_createDCtx()
     - It is necessary to init context before starting
       + compression : any ZSTD_compressBegin*() variant, including with dictionary
       + decompression : any ZSTD_decompressBegin*() variant, including with dictionary
       + copyCCtx() and copyDCtx() can be used too
     - Block size is limited, it must be <= ZSTD_getBlockSize() <= ZSTD_BLOCKSIZE_MAX == 128 KB
       + If input is larger than a block size, it's necessary to split input data into multiple blocks
-      + For inputs larger than a single block, really consider using regular ZSTD_compress() instead.
-        Frame metadata is not that costly, and quickly becomes negligible as source size grows larger.
-    - When a block is considered not compressible enough, ZSTD_compressBlock() result will be zero.
-      In which case, nothing is produced into `dst` !
-      + User must test for such outcome and deal directly with uncompressed data
-      + ZSTD_decompressBlock() doesn't accept uncompressed data as input !!!
+      + For inputs larger than a single block, consider using regular ZSTD_compress() instead.
+        Frame metadata is not that costly, and quickly becomes negligible as source size grows larger than a block.
+    - When a block is considered not compressible enough, ZSTD_compressBlock() result will be 0 (zero) !
+      ===> In which case, nothing is produced into `dst` !
+      + User __must__ test for such outcome and deal directly with uncompressed data
+      + A block cannot be declared incompressible if ZSTD_compressBlock() return value was != 0.
+        Doing so would mess up with statistics history, leading to potential data corruption.
+      + ZSTD_decompressBlock() _doesn't accept uncompressed data as input_ !!
       + In case of multiple successive blocks, should some of them be uncompressed,
         decoder must be informed of their existence in order to follow proper history.
         Use ZSTD_insertBlock() for such a case.
 


 
 
Raw zstd block functions
size_t ZSTD_getBlockSize   (const ZSTD_CCtx* cctx);
 size_t ZSTD_compressBlock  (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 size_t ZSTD_insertBlock    (ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize);  /**< insert uncompressed block into `dctx` history. Useful for multi-blocks decompression. */
 


 
 
Index: head/sys/contrib/zstd/examples/.gitignore
===================================================================
--- head/sys/contrib/zstd/examples/.gitignore	(revision 354776)
+++ head/sys/contrib/zstd/examples/.gitignore	(nonexistent)
@@ -1,15 +0,0 @@
-#build
-simple_compression
-simple_decompression
-multiple_simple_compression
-dictionary_compression
-dictionary_decompression
-streaming_compression
-streaming_decompression
-multiple_streaming_compression
-streaming_memory_usage
-
-#test artefact
-tmp*
-test*
-*.zst
Index: head/sys/contrib/zstd/examples/streaming_compression.c
===================================================================
--- head/sys/contrib/zstd/examples/streaming_compression.c	(revision 354776)
+++ head/sys/contrib/zstd/examples/streaming_compression.c	(revision 354777)
@@ -1,119 +1,123 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 #include      // printf
 #include     // free
 #include     // memset, strcat, strlen
 #include       // presumes zstd library is installed
 #include "common.h"    // Helper functions, CHECK(), and CHECK_ZSTD()
 
 
 static void compressFile_orDie(const char* fname, const char* outName, int cLevel)
 {
     /* Open the input and output files. */
     FILE* const fin  = fopen_orDie(fname, "rb");
     FILE* const fout = fopen_orDie(outName, "wb");
     /* Create the input and output buffers.
      * They may be any size, but we recommend using these functions to size them.
      * Performance will only suffer significantly for very tiny buffers.
      */
     size_t const buffInSize = ZSTD_CStreamInSize();
     void*  const buffIn  = malloc_orDie(buffInSize);
     size_t const buffOutSize = ZSTD_CStreamOutSize();
     void*  const buffOut = malloc_orDie(buffOutSize);
 
     /* Create the context. */
     ZSTD_CCtx* const cctx = ZSTD_createCCtx();
     CHECK(cctx != NULL, "ZSTD_createCCtx() failed!");
 
     /* Set any parameters you want.
      * Here we set the compression level, and enable the checksum.
      */
     CHECK_ZSTD( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, cLevel) );
     CHECK_ZSTD( ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 1) );
 
     /* This loop read from the input file, compresses that entire chunk,
      * and writes all output produced to the output file.
      */
     size_t const toRead = buffInSize;
-    size_t read;
-    while ((read = fread_orDie(buffIn, toRead, fin))) {
+    for (;;) {
+        size_t read = fread_orDie(buffIn, toRead, fin);
         /* Select the flush mode.
          * If the read may not be finished (read == toRead) we use
          * ZSTD_e_continue. If this is the last chunk, we use ZSTD_e_end.
          * Zstd optimizes the case where the first flush mode is ZSTD_e_end,
          * since it knows it is compressing the entire source in one pass.
          */
         int const lastChunk = (read < toRead);
         ZSTD_EndDirective const mode = lastChunk ? ZSTD_e_end : ZSTD_e_continue;
         /* Set the input buffer to what we just read.
          * We compress until the input buffer is empty, each time flushing the
          * output.
          */
         ZSTD_inBuffer input = { buffIn, read, 0 };
         int finished;
         do {
             /* Compress into the output buffer and write all of the output to
              * the file so we can reuse the buffer next iteration.
              */
             ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
             size_t const remaining = ZSTD_compressStream2(cctx, &output , &input, mode);
             CHECK_ZSTD(remaining);
             fwrite_orDie(buffOut, output.pos, fout);
             /* If we're on the last chunk we're finished when zstd returns 0,
              * which means its consumed all the input AND finished the frame.
              * Otherwise, we're finished when we've consumed all the input.
              */
             finished = lastChunk ? (remaining == 0) : (input.pos == input.size);
         } while (!finished);
         CHECK(input.pos == input.size,
               "Impossible: zstd only returns 0 when the input is completely consumed!");
+
+        if (lastChunk) {
+            break;
+        }
     }
 
     ZSTD_freeCCtx(cctx);
     fclose_orDie(fout);
     fclose_orDie(fin);
     free(buffIn);
     free(buffOut);
 }
 
 
 static char* createOutFilename_orDie(const char* filename)
 {
     size_t const inL = strlen(filename);
     size_t const outL = inL + 5;
     void* const outSpace = malloc_orDie(outL);
     memset(outSpace, 0, outL);
     strcat(outSpace, filename);
     strcat(outSpace, ".zst");
     return (char*)outSpace;
 }
 
 int main(int argc, const char** argv)
 {
     const char* const exeName = argv[0];
 
     if (argc!=2) {
         printf("wrong arguments\n");
         printf("usage:\n");
         printf("%s FILE\n", exeName);
         return 1;
     }
 
     const char* const inFilename = argv[1];
 
     char* const outFilename = createOutFilename_orDie(inFilename);
     compressFile_orDie(inFilename, outFilename, 1);
 
     free(outFilename);   /* not strictly required, since program execution stops there,
                           * but some static analyzer main complain otherwise */
     return 0;
 }
Index: head/sys/contrib/zstd/examples/streaming_decompression.c
===================================================================
--- head/sys/contrib/zstd/examples/streaming_decompression.c	(revision 354776)
+++ head/sys/contrib/zstd/examples/streaming_decompression.c	(revision 354777)
@@ -1,82 +1,100 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 #include      // fprintf
 #include     // free
 #include       // presumes zstd library is installed
 #include "common.h"    // Helper functions, CHECK(), and CHECK_ZSTD()
 
 static void decompressFile_orDie(const char* fname)
 {
     FILE* const fin  = fopen_orDie(fname, "rb");
     size_t const buffInSize = ZSTD_DStreamInSize();
     void*  const buffIn  = malloc_orDie(buffInSize);
     FILE* const fout = stdout;
     size_t const buffOutSize = ZSTD_DStreamOutSize();  /* Guarantee to successfully flush at least one complete compressed block in all circumstances. */
     void*  const buffOut = malloc_orDie(buffOutSize);
 
     ZSTD_DCtx* const dctx = ZSTD_createDCtx();
     CHECK(dctx != NULL, "ZSTD_createDCtx() failed!");
 
     /* This loop assumes that the input file is one or more concatenated zstd
      * streams. This example won't work if there is trailing non-zstd data at
      * the end, but streaming decompression in general handles this case.
      * ZSTD_decompressStream() returns 0 exactly when the frame is completed,
      * and doesn't consume input after the frame.
      */
     size_t const toRead = buffInSize;
     size_t read;
+    size_t lastRet = 0;
+    int isEmpty = 1;
     while ( (read = fread_orDie(buffIn, toRead, fin)) ) {
+        isEmpty = 0;
         ZSTD_inBuffer input = { buffIn, read, 0 };
         /* Given a valid frame, zstd won't consume the last byte of the frame
          * until it has flushed all of the decompressed data of the frame.
          * Therefore, instead of checking if the return code is 0, we can
          * decompress just check if input.pos < input.size.
          */
         while (input.pos < input.size) {
             ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
             /* The return code is zero if the frame is complete, but there may
              * be multiple frames concatenated together. Zstd will automatically
              * reset the context when a frame is complete. Still, calling
              * ZSTD_DCtx_reset() can be useful to reset the context to a clean
              * state, for instance if the last decompression call returned an
              * error.
              */
             size_t const ret = ZSTD_decompressStream(dctx, &output , &input);
             CHECK_ZSTD(ret);
             fwrite_orDie(buffOut, output.pos, fout);
+            lastRet = ret;
         }
+    }
+
+    if (isEmpty) {
+        fprintf(stderr, "input is empty\n");
+        exit(1);
+    }
+
+    if (lastRet != 0) {
+        /* The last return value from ZSTD_decompressStream did not end on a
+         * frame, but we reached the end of the file! We assume this is an
+         * error, and the input was truncated.
+         */
+        fprintf(stderr, "EOF before end of stream: %zu\n", lastRet);
+        exit(1);
     }
 
     ZSTD_freeDCtx(dctx);
     fclose_orDie(fin);
     fclose_orDie(fout);
     free(buffIn);
     free(buffOut);
 }
 
 
 int main(int argc, const char** argv)
 {
     const char* const exeName = argv[0];
 
     if (argc!=2) {
         fprintf(stderr, "wrong arguments\n");
         fprintf(stderr, "usage:\n");
         fprintf(stderr, "%s FILE\n", exeName);
         return 1;
     }
 
     const char* const inFilename = argv[1];
 
     decompressFile_orDie(inFilename);
     return 0;
 }
Index: head/sys/contrib/zstd/lib/.gitignore
===================================================================
--- head/sys/contrib/zstd/lib/.gitignore	(revision 354776)
+++ head/sys/contrib/zstd/lib/.gitignore	(nonexistent)
@@ -1,3 +0,0 @@
-# make install artefact
-libzstd.pc
-libzstd-nomt
Index: head/sys/contrib/zstd/lib/Makefile
===================================================================
--- head/sys/contrib/zstd/lib/Makefile	(revision 354776)
+++ head/sys/contrib/zstd/lib/Makefile	(revision 354777)
@@ -1,291 +1,289 @@
 # ################################################################
 # Copyright (c) 2015-present, Yann Collet, Facebook, Inc.
 # All rights reserved.
 #
 # This source code is licensed under both the BSD-style license (found in the
 # LICENSE file in the root directory of this source tree) and the GPLv2 (found
 # in the COPYING file in the root directory of this source tree).
 # ################################################################
 
 # Version numbers
 LIBVER_MAJOR_SCRIPT:=`sed -n '/define ZSTD_VERSION_MAJOR/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < ./zstd.h`
 LIBVER_MINOR_SCRIPT:=`sed -n '/define ZSTD_VERSION_MINOR/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < ./zstd.h`
 LIBVER_PATCH_SCRIPT:=`sed -n '/define ZSTD_VERSION_RELEASE/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < ./zstd.h`
 LIBVER_SCRIPT:= $(LIBVER_MAJOR_SCRIPT).$(LIBVER_MINOR_SCRIPT).$(LIBVER_PATCH_SCRIPT)
 LIBVER_MAJOR := $(shell echo $(LIBVER_MAJOR_SCRIPT))
 LIBVER_MINOR := $(shell echo $(LIBVER_MINOR_SCRIPT))
 LIBVER_PATCH := $(shell echo $(LIBVER_PATCH_SCRIPT))
 LIBVER := $(shell echo $(LIBVER_SCRIPT))
 VERSION?= $(LIBVER)
 CCVER := $(shell $(CC) --version)
 
 CPPFLAGS+= -I. -I./common -DXXH_NAMESPACE=ZSTD_
 ifeq ($(OS),Windows_NT)   # MinGW assumed
 CPPFLAGS   += -D__USE_MINGW_ANSI_STDIO   # compatibility with %zu formatting
 endif
 CFLAGS  ?= -O3
 DEBUGFLAGS= -Wall -Wextra -Wcast-qual -Wcast-align -Wshadow \
             -Wstrict-aliasing=1 -Wswitch-enum -Wdeclaration-after-statement \
             -Wstrict-prototypes -Wundef -Wpointer-arith \
             -Wvla -Wformat=2 -Winit-self -Wfloat-equal -Wwrite-strings \
             -Wredundant-decls -Wmissing-prototypes -Wc++-compat
 CFLAGS  += $(DEBUGFLAGS) $(MOREFLAGS)
 FLAGS    = $(CPPFLAGS) $(CFLAGS)
 
 HAVE_COLORNEVER = $(shell echo a | grep --color=never a > /dev/null 2> /dev/null && echo 1 || echo 0)
 GREP_OPTIONS ?=
 ifeq ($HAVE_COLORNEVER, 1)
 GREP_OPTIONS += --color=never
 endif
 GREP = grep $(GREP_OPTIONS)
 
 ZSTDCOMMON_FILES := $(sort $(wildcard common/*.c))
 ZSTDCOMP_FILES := $(sort $(wildcard compress/*.c))
 ZSTDDECOMP_FILES := $(sort $(wildcard decompress/*.c))
 ZDICT_FILES := $(sort $(wildcard dictBuilder/*.c))
 ZDEPR_FILES := $(sort $(wildcard deprecated/*.c))
 ZSTD_FILES := $(ZSTDCOMMON_FILES)
 
 ifeq ($(findstring GCC,$(CCVER)),GCC)
 decompress/zstd_decompress_block.o :	CFLAGS+=-fno-tree-vectorize
 endif
 
 ZSTD_LEGACY_SUPPORT ?= 5
 ZSTD_LIB_COMPRESSION ?= 1
 ZSTD_LIB_DECOMPRESSION ?= 1
 ZSTD_LIB_DICTBUILDER ?= 1
 ZSTD_LIB_DEPRECATED ?= 1
 HUF_FORCE_DECOMPRESS_X1 ?= 0
 HUF_FORCE_DECOMPRESS_X2 ?= 0
 ZSTD_FORCE_DECOMPRESS_SHORT ?= 0
 ZSTD_FORCE_DECOMPRESS_LONG ?= 0
 ZSTD_NO_INLINE ?= 0
 ZSTD_STRIP_ERROR_STRINGS ?= 0
 ZSTD_LEGACY_MULTITHREADED_API ?= 0
 
 ifeq ($(ZSTD_LIB_COMPRESSION), 0)
 	ZSTD_LIB_DICTBUILDER = 0
 	ZSTD_LIB_DEPRECATED = 0
 endif
 
 ifeq ($(ZSTD_LIB_DECOMPRESSION), 0)
 	ZSTD_LEGACY_SUPPORT = 0
 	ZSTD_LIB_DEPRECATED = 0
 endif
 
 ifneq ($(ZSTD_LIB_COMPRESSION), 0)
 	ZSTD_FILES += $(ZSTDCOMP_FILES)
 endif
 
 ifneq ($(ZSTD_LIB_DECOMPRESSION), 0)
 	ZSTD_FILES += $(ZSTDDECOMP_FILES)
 endif
 
 ifneq ($(ZSTD_LIB_DEPRECATED), 0)
 	ZSTD_FILES += $(ZDEPR_FILES)
 endif
 
 ifneq ($(ZSTD_LIB_DICTBUILDER), 0)
 	ZSTD_FILES += $(ZDICT_FILES)
 endif
 
 ifneq ($(HUF_FORCE_DECOMPRESS_X1), 0)
 	CFLAGS += -DHUF_FORCE_DECOMPRESS_X1
 endif
 
 ifneq ($(HUF_FORCE_DECOMPRESS_X2), 0)
 	CFLAGS += -DHUF_FORCE_DECOMPRESS_X2
 endif
 
 ifneq ($(ZSTD_FORCE_DECOMPRESS_SHORT), 0)
 	CFLAGS += -DZSTD_FORCE_DECOMPRESS_SHORT
 endif
 
 ifneq ($(ZSTD_FORCE_DECOMPRESS_LONG), 0)
 	CFLAGS += -DZSTD_FORCE_DECOMPRESS_LONG
 endif
 
 ifneq ($(ZSTD_NO_INLINE), 0)
 	CFLAGS += -DZSTD_NO_INLINE
 endif
 
 ifneq ($(ZSTD_STRIP_ERROR_STRINGS), 0)
 	CFLAGS += -DZSTD_STRIP_ERROR_STRINGS
 endif
 
 ifneq ($(ZSTD_LEGACY_MULTITHREADED_API), 0)
 	CFLAGS += -DZSTD_LEGACY_MULTITHREADED_API
 endif
 
 ifneq ($(ZSTD_LEGACY_SUPPORT), 0)
 ifeq ($(shell test $(ZSTD_LEGACY_SUPPORT) -lt 8; echo $$?), 0)
 	ZSTD_FILES += $(shell ls legacy/*.c | $(GREP) 'v0[$(ZSTD_LEGACY_SUPPORT)-7]')
 endif
 	CPPFLAGS += -I./legacy
 endif
 CPPFLAGS  += -DZSTD_LEGACY_SUPPORT=$(ZSTD_LEGACY_SUPPORT)
 
 ZSTD_OBJ   := $(patsubst %.c,%.o,$(ZSTD_FILES))
 
 # macOS linker doesn't support -soname, and use different extension
 # see : https://developer.apple.com/library/mac/documentation/DeveloperTools/Conceptual/DynamicLibraries/100-Articles/DynamicLibraryDesignGuidelines.html
 ifeq ($(shell uname), Darwin)
 	SHARED_EXT = dylib
 	SHARED_EXT_MAJOR = $(LIBVER_MAJOR).$(SHARED_EXT)
 	SHARED_EXT_VER = $(LIBVER).$(SHARED_EXT)
 	SONAME_FLAGS = -install_name $(LIBDIR)/libzstd.$(SHARED_EXT_MAJOR) -compatibility_version $(LIBVER_MAJOR) -current_version $(LIBVER)
 else
 	SONAME_FLAGS = -Wl,-soname=libzstd.$(SHARED_EXT).$(LIBVER_MAJOR)
 	SHARED_EXT = so
 	SHARED_EXT_MAJOR = $(SHARED_EXT).$(LIBVER_MAJOR)
 	SHARED_EXT_VER = $(SHARED_EXT).$(LIBVER)
 endif
 
 
 .PHONY: default all clean install uninstall
 
 default: lib-release
 
 all: lib
 
 libzstd.a: ARFLAGS = rcs
 libzstd.a: $(ZSTD_OBJ)
 	@echo compiling static library
 	@$(AR) $(ARFLAGS) $@ $^
 
 libzstd.a-mt: CPPFLAGS += -DZSTD_MULTITHREAD
 libzstd.a-mt: libzstd.a
 
 ifneq (,$(filter Windows%,$(OS)))
 
 LIBZSTD = dll\libzstd.dll
 $(LIBZSTD): $(ZSTD_FILES)
 	@echo compiling dynamic library $(LIBVER)
 	$(CC) $(FLAGS) -DZSTD_DLL_EXPORT=1 -Wl,--out-implib,dll\libzstd.lib -shared $^ -o $@
 
 else
 
 LIBZSTD = libzstd.$(SHARED_EXT_VER)
 $(LIBZSTD): LDFLAGS += -shared -fPIC -fvisibility=hidden
 $(LIBZSTD): $(ZSTD_FILES)
 	@echo compiling dynamic library $(LIBVER)
 	@$(CC) $(FLAGS) $^ $(LDFLAGS) $(SONAME_FLAGS) -o $@
 	@echo creating versioned links
 	@ln -sf $@ libzstd.$(SHARED_EXT_MAJOR)
 	@ln -sf $@ libzstd.$(SHARED_EXT)
 
 endif
 
 
 libzstd : $(LIBZSTD)
 
 libzstd-mt : CPPFLAGS += -DZSTD_MULTITHREAD
 libzstd-mt : libzstd
 
 lib: libzstd.a libzstd
 
 lib-mt: CPPFLAGS += -DZSTD_MULTITHREAD
 lib-mt: lib
 
 lib-release lib-release-mt: DEBUGFLAGS :=
 lib-release: lib
 lib-release-mt: lib-mt
 
 # Special case : building library in single-thread mode _and_ without zstdmt_compress.c
 ZSTDMT_FILES = compress/zstdmt_compress.c
 ZSTD_NOMT_FILES = $(filter-out $(ZSTDMT_FILES),$(ZSTD_FILES))
 libzstd-nomt: LDFLAGS += -shared -fPIC -fvisibility=hidden
 libzstd-nomt: $(ZSTD_NOMT_FILES)
 	@echo compiling single-thread dynamic library $(LIBVER)
 	@echo files : $(ZSTD_NOMT_FILES)
 	@$(CC) $(FLAGS) $^ $(LDFLAGS) $(SONAME_FLAGS) -o $@
 
 clean:
 	@$(RM) -r *.dSYM   # macOS-specific
 	@$(RM) core *.o *.a *.gcda *.$(SHARED_EXT) *.$(SHARED_EXT).* libzstd.pc
 	@$(RM) dll/libzstd.dll dll/libzstd.lib libzstd-nomt*
 	@$(RM) common/*.o compress/*.o decompress/*.o dictBuilder/*.o legacy/*.o deprecated/*.o
 	@echo Cleaning library completed
 
 #-----------------------------------------------------------------------------
 # make install is validated only for Linux, macOS, BSD, Hurd and Solaris targets
 #-----------------------------------------------------------------------------
 ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU OpenBSD FreeBSD NetBSD DragonFly SunOS Haiku))
 
 DESTDIR     ?=
 # directory variables : GNU conventions prefer lowercase
 # see https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html
 # support both lower and uppercase (BSD), use uppercase in script
 prefix      ?= /usr/local
 PREFIX      ?= $(prefix)
 exec_prefix ?= $(PREFIX)
 libdir      ?= $(exec_prefix)/lib
 LIBDIR      ?= $(libdir)
 includedir  ?= $(PREFIX)/include
 INCLUDEDIR  ?= $(includedir)
 
 ifneq (,$(filter $(shell uname),FreeBSD NetBSD DragonFly))
 PKGCONFIGDIR ?= $(PREFIX)/libdata/pkgconfig
 else
 PKGCONFIGDIR ?= $(LIBDIR)/pkgconfig
 endif
 
 ifneq (,$(filter $(shell uname),SunOS))
 INSTALL ?= ginstall
 else
 INSTALL ?= install
 endif
 
 INSTALL_PROGRAM ?= $(INSTALL)
 INSTALL_DATA    ?= $(INSTALL) -m 644
 
 
 libzstd.pc:
 libzstd.pc: libzstd.pc.in
 	@echo creating pkgconfig
 	@sed -e 's|@PREFIX@|$(PREFIX)|' \
-             -e 's|@LIBDIR@|$(LIBDIR)|' \
-             -e 's|@INCLUDEDIR@|$(INCLUDEDIR)|' \
              -e 's|@VERSION@|$(VERSION)|' \
              $< >$@
 
 install: install-pc install-static install-shared install-includes
 	@echo zstd static and shared library installed
 
 install-pc: libzstd.pc
 	@$(INSTALL) -d -m 755 $(DESTDIR)$(PKGCONFIGDIR)/
 	@$(INSTALL_DATA) libzstd.pc $(DESTDIR)$(PKGCONFIGDIR)/
 
 install-static: libzstd.a
 	@echo Installing static library
 	@$(INSTALL) -d -m 755 $(DESTDIR)$(LIBDIR)/
 	@$(INSTALL_DATA) libzstd.a $(DESTDIR)$(LIBDIR)
 
 install-shared: libzstd
 	@echo Installing shared library
 	@$(INSTALL) -d -m 755 $(DESTDIR)$(LIBDIR)/
 	@$(INSTALL_PROGRAM) $(LIBZSTD) $(DESTDIR)$(LIBDIR)
 	@ln -sf $(LIBZSTD) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT_MAJOR)
 	@ln -sf $(LIBZSTD) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT)
 
 install-includes:
 	@echo Installing includes
 	@$(INSTALL) -d -m 755 $(DESTDIR)$(INCLUDEDIR)/
 	@$(INSTALL_DATA) zstd.h $(DESTDIR)$(INCLUDEDIR)
 	@$(INSTALL_DATA) common/zstd_errors.h $(DESTDIR)$(INCLUDEDIR)
 	@$(INSTALL_DATA) deprecated/zbuff.h $(DESTDIR)$(INCLUDEDIR)     # prototypes generate deprecation warnings
 	@$(INSTALL_DATA) dictBuilder/zdict.h $(DESTDIR)$(INCLUDEDIR)
 
 uninstall:
 	@$(RM) $(DESTDIR)$(LIBDIR)/libzstd.a
 	@$(RM) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT)
 	@$(RM) $(DESTDIR)$(LIBDIR)/libzstd.$(SHARED_EXT_MAJOR)
 	@$(RM) $(DESTDIR)$(LIBDIR)/$(LIBZSTD)
 	@$(RM) $(DESTDIR)$(PKGCONFIGDIR)/libzstd.pc
 	@$(RM) $(DESTDIR)$(INCLUDEDIR)/zstd.h
 	@$(RM) $(DESTDIR)$(INCLUDEDIR)/zstd_errors.h
 	@$(RM) $(DESTDIR)$(INCLUDEDIR)/zbuff.h   # Deprecated streaming functions
 	@$(RM) $(DESTDIR)$(INCLUDEDIR)/zdict.h
 	@echo zstd libraries successfully uninstalled
 
 endif
Index: head/sys/contrib/zstd/lib/README.md
===================================================================
--- head/sys/contrib/zstd/lib/README.md	(revision 354776)
+++ head/sys/contrib/zstd/lib/README.md	(revision 354777)
@@ -1,148 +1,159 @@
 Zstandard library files
 ================================
 
 The __lib__ directory is split into several sub-directories,
 in order to make it easier to select or exclude features.
 
 
 #### Building
 
 `Makefile` script is provided, supporting [Makefile conventions](https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html#Makefile-Conventions),
 including commands variables, staged install, directory variables and standard targets.
 - `make` : generates both static and dynamic libraries
 - `make install` : install libraries and headers in target system directories
 
 `libzstd` default scope is pretty large, including compression, decompression, dictionary builder,
 and support for decoding legacy formats >= v0.5.0.
 The scope can be reduced on demand (see paragraph _modular build_).
 
 
 #### Multithreading support
 
 Multithreading is disabled by default when building with `make`.
 Enabling multithreading requires 2 conditions :
 - set build macro `ZSTD_MULTITHREAD` (`-DZSTD_MULTITHREAD` for `gcc`)
 - for POSIX systems : compile with pthread (`-pthread` compilation flag for `gcc`)
 
 Both conditions are automatically applied when invoking `make lib-mt` target.
 
 When linking a POSIX program with a multithreaded version of `libzstd`,
-note that it's necessary to request the `-pthread` flag during link stage.
+note that it's necessary to invoke the `-pthread` flag during link stage.
 
 Multithreading capabilities are exposed
-via the [advanced API defined in `lib/zstd.h`](https://github.com/facebook/zstd/blob/v1.3.8/lib/zstd.h#L592).
+via the [advanced API defined in `lib/zstd.h`](https://github.com/facebook/zstd/blob/v1.4.3/lib/zstd.h#L351).
 
 
 #### API
 
 Zstandard's stable API is exposed within [lib/zstd.h](zstd.h).
 
 
 #### Advanced API
 
 Optional advanced features are exposed via :
 
 - `lib/common/zstd_errors.h` : translates `size_t` function results
                                into a `ZSTD_ErrorCode`, for accurate error handling.
 
 - `ZSTD_STATIC_LINKING_ONLY` : if this macro is defined _before_ including `zstd.h`,
                           it unlocks access to the experimental API,
                           exposed in the second part of `zstd.h`.
                           All definitions in the experimental APIs are unstable,
                           they may still change in the future, or even be removed.
                           As a consequence, experimental definitions shall ___never be used with dynamic library___ !
                           Only static linking is allowed.
 
 
 #### Modular build
 
 It's possible to compile only a limited set of features within `libzstd`.
 The file structure is designed to make this selection manually achievable for any build system :
 
 - Directory `lib/common` is always required, for all variants.
 
 - Compression source code lies in `lib/compress`
 
 - Decompression source code lies in `lib/decompress`
 
 - It's possible to include only `compress` or only `decompress`, they don't depend on each other.
 
 - `lib/dictBuilder` : makes it possible to generate dictionaries from a set of samples.
         The API is exposed in `lib/dictBuilder/zdict.h`.
         This module depends on both `lib/common` and `lib/compress` .
 
 - `lib/legacy` : makes it possible to decompress legacy zstd formats, starting from `v0.1.0`.
         This module depends on `lib/common` and `lib/decompress`.
         To enable this feature, define `ZSTD_LEGACY_SUPPORT` during compilation.
         Specifying a number limits versions supported to that version onward.
         For example, `ZSTD_LEGACY_SUPPORT=2` means : "support legacy formats >= v0.2.0".
         Conversely, `ZSTD_LEGACY_SUPPORT=0` means "do __not__ support legacy formats".
         By default, this build macro is set as `ZSTD_LEGACY_SUPPORT=5`.
         Decoding supported legacy format is a transparent capability triggered within decompression functions.
         It's also allowed to invoke legacy API directly, exposed in `lib/legacy/zstd_legacy.h`.
         Each version does also provide its own set of advanced API.
         For example, advanced API for version `v0.4` is exposed in `lib/legacy/zstd_v04.h` .
 
 - While invoking `make libzstd`, it's possible to define build macros
         `ZSTD_LIB_COMPRESSION, ZSTD_LIB_DECOMPRESSION`, `ZSTD_LIB_DICTBUILDER`,
         and `ZSTD_LIB_DEPRECATED` as `0` to forgo compilation of the corresponding features.
         This will also disable compilation of all dependencies
         (eg. `ZSTD_LIB_COMPRESSION=0` will also disable dictBuilder).
 
 - There are some additional build macros that can be used to minify the decoder.
 
   Zstandard often has more than one implementation of a piece of functionality,
   where each implementation optimizes for different scenarios. For example, the
   Huffman decoder has complementary implementations that decode the stream one
   symbol at a time or two symbols at a time. Zstd normally includes both (and
   dispatches between them at runtime), but by defining `HUF_FORCE_DECOMPRESS_X1`
   or `HUF_FORCE_DECOMPRESS_X2`, you can force the use of one or the other, avoiding
   compilation of the other. Similarly, `ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT`
   and `ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG` force the compilation and use of
   only one or the other of two decompression implementations. The smallest
   binary is achieved by using `HUF_FORCE_DECOMPRESS_X1` and
   `ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT`.
 
   For squeezing the last ounce of size out, you can also define
   `ZSTD_NO_INLINE`, which disables inlining, and `ZSTD_STRIP_ERROR_STRINGS`,
   which removes the error messages that are otherwise returned by
   `ZSTD_getErrorName`.
 
 - While invoking `make libzstd`, the build macro `ZSTD_LEGACY_MULTITHREADED_API=1`
   will expose the deprecated `ZSTDMT` API exposed by `zstdmt_compress.h` in
   the shared library, which is now hidden by default.
+
+- The build macro `DYNAMIC_BMI2` can be set to 1 or 0 in order to generate binaries
+  which can detect at runtime the presence of BMI2 instructions, and use them only if present.
+  These instructions contribute to better performance, notably on the decoder side.
+  By default, this feature is automatically enabled on detecting
+  the right instruction set (x64) and compiler (clang or gcc >= 5).
+  It's obviously disabled for different cpus,
+  or when BMI2 instruction set is _required_ by the compiler command line
+  (in this case, only the BMI2 code path is generated).
+  Setting this macro will either force to generate the BMI2 dispatcher (1)
+  or prevent it (0). It overrides automatic detection.
 
 
 #### Windows : using MinGW+MSYS to create DLL
 
 DLL can be created using MinGW+MSYS with the `make libzstd` command.
 This command creates `dll\libzstd.dll` and the import library `dll\libzstd.lib`.
 The import library is only required with Visual C++.
 The header file `zstd.h` and the dynamic library `dll\libzstd.dll` are required to
 compile a project using gcc/MinGW.
 The dynamic library has to be added to linking options.
 It means that if a project that uses ZSTD consists of a single `test-dll.c`
 file it should be linked with `dll\libzstd.dll`. For example:
 ```
     gcc $(CFLAGS) -Iinclude/ test-dll.c -o test-dll dll\libzstd.dll
 ```
 The compiled executable will require ZSTD DLL which is available at `dll\libzstd.dll`.
 
 
 #### Deprecated API
 
 Obsolete API on their way out are stored in directory `lib/deprecated`.
 At this stage, it contains older streaming prototypes, in `lib/deprecated/zbuff.h`.
 These prototypes will be removed in some future version.
 Consider migrating code towards supported streaming API exposed in `zstd.h`.
 
 
 #### Miscellaneous
 
 The other files are not source code. There are :
 
  - `BUCK` : support for `buck` build system (https://buckbuild.com/)
  - `Makefile` : `make` script to build and install zstd library (static and dynamic)
  - `README.md` : this file
  - `dll/` : resources directory for Windows compilation
  - `libzstd.pc.in` : script for `pkg-config` (used in `make install`)
Index: head/sys/contrib/zstd/lib/common/bitstream.h
===================================================================
--- head/sys/contrib/zstd/lib/common/bitstream.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/bitstream.h	(revision 354777)
@@ -1,455 +1,460 @@
 /* ******************************************************************
    bitstream
    Part of FSE library
    Copyright (C) 2013-present, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 ****************************************************************** */
 #ifndef BITSTREAM_H_MODULE
 #define BITSTREAM_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /*
 *  This API consists of small unitary functions, which must be inlined for best performance.
 *  Since link-time-optimization is not available for all compilers,
 *  these functions are defined into a .h to be included.
 */
 
 /*-****************************************
 *  Dependencies
 ******************************************/
 #include "mem.h"            /* unaligned access routines */
 #include "debug.h"          /* assert(), DEBUGLOG(), RAWLOG() */
 #include "error_private.h"  /* error codes and messages */
 
 
 /*=========================================
 *  Target specific
 =========================================*/
 #if defined(__BMI__) && defined(__GNUC__)
 #  include    /* support for bextr (experimental) */
+#elif defined(__ICCARM__)
+#  include 
 #endif
 
 #define STREAM_ACCUMULATOR_MIN_32  25
 #define STREAM_ACCUMULATOR_MIN_64  57
 #define STREAM_ACCUMULATOR_MIN    ((U32)(MEM_32bits() ? STREAM_ACCUMULATOR_MIN_32 : STREAM_ACCUMULATOR_MIN_64))
 
 
 /*-******************************************
 *  bitStream encoding API (write forward)
 ********************************************/
 /* bitStream can mix input from multiple sources.
  * A critical property of these streams is that they encode and decode in **reverse** direction.
  * So the first bit sequence you add will be the last to be read, like a LIFO stack.
  */
 typedef struct {
     size_t bitContainer;
     unsigned bitPos;
     char*  startPtr;
     char*  ptr;
     char*  endPtr;
 } BIT_CStream_t;
 
 MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC, void* dstBuffer, size_t dstCapacity);
 MEM_STATIC void   BIT_addBits(BIT_CStream_t* bitC, size_t value, unsigned nbBits);
 MEM_STATIC void   BIT_flushBits(BIT_CStream_t* bitC);
 MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC);
 
 /* Start with initCStream, providing the size of buffer to write into.
 *  bitStream will never write outside of this buffer.
 *  `dstCapacity` must be >= sizeof(bitD->bitContainer), otherwise @return will be an error code.
 *
 *  bits are first added to a local register.
 *  Local register is size_t, hence 64-bits on 64-bits systems, or 32-bits on 32-bits systems.
 *  Writing data into memory is an explicit operation, performed by the flushBits function.
 *  Hence keep track how many bits are potentially stored into local register to avoid register overflow.
 *  After a flushBits, a maximum of 7 bits might still be stored into local register.
 *
 *  Avoid storing elements of more than 24 bits if you want compatibility with 32-bits bitstream readers.
 *
 *  Last operation is to close the bitStream.
 *  The function returns the final size of CStream in bytes.
 *  If data couldn't fit into `dstBuffer`, it will return a 0 ( == not storable)
 */
 
 
 /*-********************************************
 *  bitStream decoding API (read backward)
 **********************************************/
 typedef struct {
     size_t   bitContainer;
     unsigned bitsConsumed;
     const char* ptr;
     const char* start;
     const char* limitPtr;
 } BIT_DStream_t;
 
 typedef enum { BIT_DStream_unfinished = 0,
                BIT_DStream_endOfBuffer = 1,
                BIT_DStream_completed = 2,
                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
 
 MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
 MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
 
 
 /* Start by invoking BIT_initDStream().
 *  A chunk of the bitStream is then stored into a local register.
 *  Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
 *  You can then retrieve bitFields stored into the local register, **in reverse order**.
 *  Local register is explicitly reloaded from memory by the BIT_reloadDStream() method.
 *  A reload guarantee a minimum of ((8*sizeof(bitD->bitContainer))-7) bits when its result is BIT_DStream_unfinished.
 *  Otherwise, it can be less than that, so proceed accordingly.
 *  Checking if DStream has reached its end can be performed with BIT_endOfDStream().
 */
 
 
 /*-****************************************
 *  unsafe API
 ******************************************/
 MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC, size_t value, unsigned nbBits);
 /* faster, but works only if value is "clean", meaning all high bits above nbBits are 0 */
 
 MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC);
 /* unsafe version; does not check buffer overflow */
 
 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
 /* faster, but works only if nbBits >= 1 */
 
 
 
 /*-**************************************************************
 *  Internal functions
 ****************************************************************/
 MEM_STATIC unsigned BIT_highbit32 (U32 val)
 {
     assert(val != 0);
     {
 #   if defined(_MSC_VER)   /* Visual */
         unsigned long r=0;
         _BitScanReverse ( &r, val );
         return (unsigned) r;
 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
-        return 31 - __builtin_clz (val);
+        return __builtin_clz (val) ^ 31;
+#   elif defined(__ICCARM__)    /* IAR Intrinsic */
+        return 31 - __CLZ(val);
 #   else   /* Software version */
         static const unsigned DeBruijnClz[32] = { 0,  9,  1, 10, 13, 21,  2, 29,
                                                  11, 14, 16, 18, 22, 25,  3, 30,
                                                   8, 12, 20, 28, 15, 17, 24,  7,
                                                  19, 27, 23,  6, 26,  5,  4, 31 };
         U32 v = val;
         v |= v >> 1;
         v |= v >> 2;
         v |= v >> 4;
         v |= v >> 8;
         v |= v >> 16;
         return DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
 #   endif
     }
 }
 
 /*=====    Local Constants   =====*/
 static const unsigned BIT_mask[] = {
     0,          1,         3,         7,         0xF,       0x1F,
     0x3F,       0x7F,      0xFF,      0x1FF,     0x3FF,     0x7FF,
     0xFFF,      0x1FFF,    0x3FFF,    0x7FFF,    0xFFFF,    0x1FFFF,
     0x3FFFF,    0x7FFFF,   0xFFFFF,   0x1FFFFF,  0x3FFFFF,  0x7FFFFF,
     0xFFFFFF,   0x1FFFFFF, 0x3FFFFFF, 0x7FFFFFF, 0xFFFFFFF, 0x1FFFFFFF,
     0x3FFFFFFF, 0x7FFFFFFF}; /* up to 31 bits */
 #define BIT_MASK_SIZE (sizeof(BIT_mask) / sizeof(BIT_mask[0]))
 
 /*-**************************************************************
 *  bitStream encoding
 ****************************************************************/
 /*! BIT_initCStream() :
  *  `dstCapacity` must be > sizeof(size_t)
  *  @return : 0 if success,
  *            otherwise an error code (can be tested using ERR_isError()) */
 MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC,
                                   void* startPtr, size_t dstCapacity)
 {
     bitC->bitContainer = 0;
     bitC->bitPos = 0;
     bitC->startPtr = (char*)startPtr;
     bitC->ptr = bitC->startPtr;
     bitC->endPtr = bitC->startPtr + dstCapacity - sizeof(bitC->bitContainer);
     if (dstCapacity <= sizeof(bitC->bitContainer)) return ERROR(dstSize_tooSmall);
     return 0;
 }
 
 /*! BIT_addBits() :
  *  can add up to 31 bits into `bitC`.
  *  Note : does not check for register overflow ! */
 MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC,
                             size_t value, unsigned nbBits)
 {
     MEM_STATIC_ASSERT(BIT_MASK_SIZE == 32);
     assert(nbBits < BIT_MASK_SIZE);
     assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
     bitC->bitContainer |= (value & BIT_mask[nbBits]) << bitC->bitPos;
     bitC->bitPos += nbBits;
 }
 
 /*! BIT_addBitsFast() :
  *  works only if `value` is _clean_,
  *  meaning all high bits above nbBits are 0 */
 MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC,
                                 size_t value, unsigned nbBits)
 {
     assert((value>>nbBits) == 0);
     assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
     bitC->bitContainer |= value << bitC->bitPos;
     bitC->bitPos += nbBits;
 }
 
 /*! BIT_flushBitsFast() :
  *  assumption : bitContainer has not overflowed
  *  unsafe version; does not check buffer overflow */
 MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC)
 {
     size_t const nbBytes = bitC->bitPos >> 3;
     assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
+    assert(bitC->ptr <= bitC->endPtr);
     MEM_writeLEST(bitC->ptr, bitC->bitContainer);
     bitC->ptr += nbBytes;
-    assert(bitC->ptr <= bitC->endPtr);
     bitC->bitPos &= 7;
     bitC->bitContainer >>= nbBytes*8;
 }
 
 /*! BIT_flushBits() :
  *  assumption : bitContainer has not overflowed
  *  safe version; check for buffer overflow, and prevents it.
  *  note : does not signal buffer overflow.
  *  overflow will be revealed later on using BIT_closeCStream() */
 MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC)
 {
     size_t const nbBytes = bitC->bitPos >> 3;
     assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
+    assert(bitC->ptr <= bitC->endPtr);
     MEM_writeLEST(bitC->ptr, bitC->bitContainer);
     bitC->ptr += nbBytes;
     if (bitC->ptr > bitC->endPtr) bitC->ptr = bitC->endPtr;
     bitC->bitPos &= 7;
     bitC->bitContainer >>= nbBytes*8;
 }
 
 /*! BIT_closeCStream() :
  *  @return : size of CStream, in bytes,
  *            or 0 if it could not fit into dstBuffer */
 MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC)
 {
     BIT_addBitsFast(bitC, 1, 1);   /* endMark */
     BIT_flushBits(bitC);
     if (bitC->ptr >= bitC->endPtr) return 0; /* overflow detected */
     return (bitC->ptr - bitC->startPtr) + (bitC->bitPos > 0);
 }
 
 
 /*-********************************************************
 *  bitStream decoding
 **********************************************************/
 /*! BIT_initDStream() :
  *  Initialize a BIT_DStream_t.
  * `bitD` : a pointer to an already allocated BIT_DStream_t structure.
  * `srcSize` must be the *exact* size of the bitStream, in bytes.
  * @return : size of stream (== srcSize), or an errorCode if a problem is detected
  */
 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
 {
     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
 
     bitD->start = (const char*)srcBuffer;
     bitD->limitPtr = bitD->start + sizeof(bitD->bitContainer);
 
     if (srcSize >=  sizeof(bitD->bitContainer)) {  /* normal case */
         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(bitD->bitContainer);
         bitD->bitContainer = MEM_readLEST(bitD->ptr);
         { BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
           bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;  /* ensures bitsConsumed is always set */
           if (lastByte == 0) return ERROR(GENERIC); /* endMark not present */ }
     } else {
         bitD->ptr   = bitD->start;
         bitD->bitContainer = *(const BYTE*)(bitD->start);
         switch(srcSize)
         {
         case 7: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[6]) << (sizeof(bitD->bitContainer)*8 - 16);
                 /* fall-through */
 
         case 6: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[5]) << (sizeof(bitD->bitContainer)*8 - 24);
                 /* fall-through */
 
         case 5: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[4]) << (sizeof(bitD->bitContainer)*8 - 32);
                 /* fall-through */
 
         case 4: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[3]) << 24;
                 /* fall-through */
 
         case 3: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[2]) << 16;
                 /* fall-through */
 
         case 2: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[1]) <<  8;
                 /* fall-through */
 
         default: break;
         }
         {   BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
             bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
             if (lastByte == 0) return ERROR(corruption_detected);  /* endMark not present */
         }
         bitD->bitsConsumed += (U32)(sizeof(bitD->bitContainer) - srcSize)*8;
     }
 
     return srcSize;
 }
 
 MEM_STATIC size_t BIT_getUpperBits(size_t bitContainer, U32 const start)
 {
     return bitContainer >> start;
 }
 
 MEM_STATIC size_t BIT_getMiddleBits(size_t bitContainer, U32 const start, U32 const nbBits)
 {
     U32 const regMask = sizeof(bitContainer)*8 - 1;
     /* if start > regMask, bitstream is corrupted, and result is undefined */
     assert(nbBits < BIT_MASK_SIZE);
     return (bitContainer >> (start & regMask)) & BIT_mask[nbBits];
 }
 
 MEM_STATIC size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits)
 {
     assert(nbBits < BIT_MASK_SIZE);
     return bitContainer & BIT_mask[nbBits];
 }
 
 /*! BIT_lookBits() :
  *  Provides next n bits from local register.
  *  local register is not modified.
  *  On 32-bits, maxNbBits==24.
  *  On 64-bits, maxNbBits==56.
  * @return : value extracted */
 MEM_STATIC size_t BIT_lookBits(const BIT_DStream_t* bitD, U32 nbBits)
 {
     /* arbitrate between double-shift and shift+mask */
 #if 1
     /* if bitD->bitsConsumed + nbBits > sizeof(bitD->bitContainer)*8,
      * bitstream is likely corrupted, and result is undefined */
     return BIT_getMiddleBits(bitD->bitContainer, (sizeof(bitD->bitContainer)*8) - bitD->bitsConsumed - nbBits, nbBits);
 #else
     /* this code path is slower on my os-x laptop */
     U32 const regMask = sizeof(bitD->bitContainer)*8 - 1;
     return ((bitD->bitContainer << (bitD->bitsConsumed & regMask)) >> 1) >> ((regMask-nbBits) & regMask);
 #endif
 }
 
 /*! BIT_lookBitsFast() :
  *  unsafe version; only works if nbBits >= 1 */
 MEM_STATIC size_t BIT_lookBitsFast(const BIT_DStream_t* bitD, U32 nbBits)
 {
     U32 const regMask = sizeof(bitD->bitContainer)*8 - 1;
     assert(nbBits >= 1);
     return (bitD->bitContainer << (bitD->bitsConsumed & regMask)) >> (((regMask+1)-nbBits) & regMask);
 }
 
 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     bitD->bitsConsumed += nbBits;
 }
 
 /*! BIT_readBits() :
  *  Read (consume) next n bits from local register and update.
  *  Pay attention to not read more than nbBits contained into local register.
  * @return : extracted value. */
 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits)
 {
     size_t const value = BIT_lookBits(bitD, nbBits);
     BIT_skipBits(bitD, nbBits);
     return value;
 }
 
 /*! BIT_readBitsFast() :
  *  unsafe version; only works only if nbBits >= 1 */
 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits)
 {
     size_t const value = BIT_lookBitsFast(bitD, nbBits);
     assert(nbBits >= 1);
     BIT_skipBits(bitD, nbBits);
     return value;
 }
 
 /*! BIT_reloadDStream() :
  *  Refill `bitD` from buffer previously set in BIT_initDStream() .
  *  This function is safe, it guarantees it will not read beyond src buffer.
  * @return : status of `BIT_DStream_t` internal register.
  *           when status == BIT_DStream_unfinished, internal register is filled with at least 25 or 57 bits */
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
 {
     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* overflow detected, like end of stream */
         return BIT_DStream_overflow;
 
     if (bitD->ptr >= bitD->limitPtr) {
         bitD->ptr -= bitD->bitsConsumed >> 3;
         bitD->bitsConsumed &= 7;
         bitD->bitContainer = MEM_readLEST(bitD->ptr);
         return BIT_DStream_unfinished;
     }
     if (bitD->ptr == bitD->start) {
         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
         return BIT_DStream_completed;
     }
     /* start < ptr < limitPtr */
     {   U32 nbBytes = bitD->bitsConsumed >> 3;
         BIT_DStream_status result = BIT_DStream_unfinished;
         if (bitD->ptr - nbBytes < bitD->start) {
             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
             result = BIT_DStream_endOfBuffer;
         }
         bitD->ptr -= nbBytes;
         bitD->bitsConsumed -= nbBytes*8;
         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD->bitContainer), otherwise bitD->ptr == bitD->start */
         return result;
     }
 }
 
 /*! BIT_endOfDStream() :
  * @return : 1 if DStream has _exactly_ reached its end (all bits consumed).
  */
 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
 {
     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
 }
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* BITSTREAM_H_MODULE */
Index: head/sys/contrib/zstd/lib/common/compiler.h
===================================================================
--- head/sys/contrib/zstd/lib/common/compiler.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/compiler.h	(revision 354777)
@@ -1,147 +1,159 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_COMPILER_H
 #define ZSTD_COMPILER_H
 
 /*-*******************************************************
 *  Compiler specifics
 *********************************************************/
 /* force inlining */
 
 #if !defined(ZSTD_NO_INLINE)
 #if defined (__GNUC__) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 #  define INLINE_KEYWORD inline
 #else
 #  define INLINE_KEYWORD
 #endif
 
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__ICCARM__)
 #  define FORCE_INLINE_ATTR __attribute__((always_inline))
 #elif defined(_MSC_VER)
 #  define FORCE_INLINE_ATTR __forceinline
 #else
 #  define FORCE_INLINE_ATTR
 #endif
 
 #else
 
 #define INLINE_KEYWORD
 #define FORCE_INLINE_ATTR
 
 #endif
 
 /**
  * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant
  * parameters. They must be inlined for the compiler to eliminate the constant
  * branches.
  */
 #define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR
 /**
  * HINT_INLINE is used to help the compiler generate better code. It is *not*
  * used for "templates", so it can be tweaked based on the compilers
  * performance.
  *
  * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the
  * always_inline attribute.
  *
  * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline
  * attribute.
  */
 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5
 #  define HINT_INLINE static INLINE_KEYWORD
 #else
 #  define HINT_INLINE static INLINE_KEYWORD FORCE_INLINE_ATTR
 #endif
 
+/* UNUSED_ATTR tells the compiler it is okay if the function is unused. */
+#if defined(__GNUC__)
+#  define UNUSED_ATTR __attribute__((unused))
+#else
+#  define UNUSED_ATTR
+#endif
+
 /* force no inlining */
 #ifdef _MSC_VER
 #  define FORCE_NOINLINE static __declspec(noinline)
 #else
-#  ifdef __GNUC__
+#  if defined(__GNUC__) || defined(__ICCARM__)
 #    define FORCE_NOINLINE static __attribute__((__noinline__))
 #  else
 #    define FORCE_NOINLINE static
 #  endif
 #endif
 
 /* target attribute */
 #ifndef __has_attribute
   #define __has_attribute(x) 0  /* Compatibility with non-clang compilers. */
 #endif
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__ICCARM__)
 #  define TARGET_ATTRIBUTE(target) __attribute__((__target__(target)))
 #else
 #  define TARGET_ATTRIBUTE(target)
 #endif
 
 /* Enable runtime BMI2 dispatch based on the CPU.
  * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default.
  */
 #ifndef DYNAMIC_BMI2
   #if ((defined(__clang__) && __has_attribute(__target__)) \
       || (defined(__GNUC__) \
           && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \
       && (defined(__x86_64__) || defined(_M_X86)) \
       && !defined(__BMI2__)
   #  define DYNAMIC_BMI2 1
   #else
   #  define DYNAMIC_BMI2 0
   #endif
 #endif
 
 /* prefetch
  * can be disabled, by declaring NO_PREFETCH build macro */
 #if defined(NO_PREFETCH)
 #  define PREFETCH_L1(ptr)  (void)(ptr)  /* disabled */
 #  define PREFETCH_L2(ptr)  (void)(ptr)  /* disabled */
 #else
 #  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86))  /* _mm_prefetch() is not defined outside of x86/x64 */
 #    include    /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
 #    define PREFETCH_L1(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
 #    define PREFETCH_L2(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T1)
 #  elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
 #    define PREFETCH_L1(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
 #    define PREFETCH_L2(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */)
 #  else
 #    define PREFETCH_L1(ptr) (void)(ptr)  /* disabled */
 #    define PREFETCH_L2(ptr) (void)(ptr)  /* disabled */
 #  endif
 #endif  /* NO_PREFETCH */
 
 #define CACHELINE_SIZE 64
 
 #define PREFETCH_AREA(p, s)  {            \
     const char* const _ptr = (const char*)(p);  \
     size_t const _size = (size_t)(s);     \
     size_t _pos;                          \
     for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) {  \
         PREFETCH_L2(_ptr + _pos);         \
     }                                     \
 }
 
-/* vectorization */
+/* vectorization
+ * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax */
 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ > 5
-#  define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize")))
+#  if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5)
+#    define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize")))
+#  else
+#    define DONT_VECTORIZE _Pragma("GCC optimize(\"no-tree-vectorize\")")
+#  endif
 #else
 #  define DONT_VECTORIZE
 #endif
 
 /* disable warnings */
 #ifdef _MSC_VER    /* Visual Studio */
 #  include                     /* For Visual 2005 */
 #  pragma warning(disable : 4100)        /* disable: C4100: unreferenced formal parameter */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
 #endif
 
 #endif /* ZSTD_COMPILER_H */
Index: head/sys/contrib/zstd/lib/common/fse.h
===================================================================
--- head/sys/contrib/zstd/lib/common/fse.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/fse.h	(revision 354777)
@@ -1,708 +1,708 @@
 /* ******************************************************************
    FSE : Finite State Entropy codec
    Public Prototypes declaration
    Copyright (C) 2013-2016, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 ****************************************************************** */
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #ifndef FSE_H
 #define FSE_H
 
 
 /*-*****************************************
 *  Dependencies
 ******************************************/
 #include     /* size_t, ptrdiff_t */
 
 
 /*-*****************************************
 *  FSE_PUBLIC_API : control library symbols visibility
 ******************************************/
 #if defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1) && defined(__GNUC__) && (__GNUC__ >= 4)
 #  define FSE_PUBLIC_API __attribute__ ((visibility ("default")))
 #elif defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1)   /* Visual expected */
 #  define FSE_PUBLIC_API __declspec(dllexport)
 #elif defined(FSE_DLL_IMPORT) && (FSE_DLL_IMPORT==1)
 #  define FSE_PUBLIC_API __declspec(dllimport) /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
 #else
 #  define FSE_PUBLIC_API
 #endif
 
 /*------   Version   ------*/
 #define FSE_VERSION_MAJOR    0
 #define FSE_VERSION_MINOR    9
 #define FSE_VERSION_RELEASE  0
 
 #define FSE_LIB_VERSION FSE_VERSION_MAJOR.FSE_VERSION_MINOR.FSE_VERSION_RELEASE
 #define FSE_QUOTE(str) #str
 #define FSE_EXPAND_AND_QUOTE(str) FSE_QUOTE(str)
 #define FSE_VERSION_STRING FSE_EXPAND_AND_QUOTE(FSE_LIB_VERSION)
 
 #define FSE_VERSION_NUMBER  (FSE_VERSION_MAJOR *100*100 + FSE_VERSION_MINOR *100 + FSE_VERSION_RELEASE)
 FSE_PUBLIC_API unsigned FSE_versionNumber(void);   /**< library version number; to be used when checking dll version */
 
 
 /*-****************************************
 *  FSE simple functions
 ******************************************/
 /*! FSE_compress() :
     Compress content of buffer 'src', of size 'srcSize', into destination buffer 'dst'.
     'dst' buffer must be already allocated. Compression runs faster is dstCapacity >= FSE_compressBound(srcSize).
     @return : size of compressed data (<= dstCapacity).
     Special values : if return == 0, srcData is not compressible => Nothing is stored within dst !!!
                      if return == 1, srcData is a single byte symbol * srcSize times. Use RLE compression instead.
                      if FSE_isError(return), compression failed (more details using FSE_getErrorName())
 */
 FSE_PUBLIC_API size_t FSE_compress(void* dst, size_t dstCapacity,
                              const void* src, size_t srcSize);
 
 /*! FSE_decompress():
     Decompress FSE data from buffer 'cSrc', of size 'cSrcSize',
     into already allocated destination buffer 'dst', of size 'dstCapacity'.
     @return : size of regenerated data (<= maxDstSize),
               or an error code, which can be tested using FSE_isError() .
 
     ** Important ** : FSE_decompress() does not decompress non-compressible nor RLE data !!!
     Why ? : making this distinction requires a header.
     Header management is intentionally delegated to the user layer, which can better manage special cases.
 */
 FSE_PUBLIC_API size_t FSE_decompress(void* dst,  size_t dstCapacity,
                                const void* cSrc, size_t cSrcSize);
 
 
 /*-*****************************************
 *  Tool functions
 ******************************************/
 FSE_PUBLIC_API size_t FSE_compressBound(size_t size);       /* maximum compressed size */
 
 /* Error Management */
 FSE_PUBLIC_API unsigned    FSE_isError(size_t code);        /* tells if a return value is an error code */
 FSE_PUBLIC_API const char* FSE_getErrorName(size_t code);   /* provides error code string (useful for debugging) */
 
 
 /*-*****************************************
 *  FSE advanced functions
 ******************************************/
 /*! FSE_compress2() :
     Same as FSE_compress(), but allows the selection of 'maxSymbolValue' and 'tableLog'
     Both parameters can be defined as '0' to mean : use default value
     @return : size of compressed data
     Special values : if return == 0, srcData is not compressible => Nothing is stored within cSrc !!!
                      if return == 1, srcData is a single byte symbol * srcSize times. Use RLE compression.
                      if FSE_isError(return), it's an error code.
 */
 FSE_PUBLIC_API size_t FSE_compress2 (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
 
 
 /*-*****************************************
 *  FSE detailed API
 ******************************************/
 /*!
 FSE_compress() does the following:
 1. count symbol occurrence from source[] into table count[] (see hist.h)
 2. normalize counters so that sum(count[]) == Power_of_2 (2^tableLog)
 3. save normalized counters to memory buffer using writeNCount()
 4. build encoding table 'CTable' from normalized counters
 5. encode the data stream using encoding table 'CTable'
 
 FSE_decompress() does the following:
 1. read normalized counters with readNCount()
 2. build decoding table 'DTable' from normalized counters
 3. decode the data stream using decoding table 'DTable'
 
 The following API allows targeting specific sub-functions for advanced tasks.
 For example, it's possible to compress several blocks using the same 'CTable',
 or to save and provide normalized distribution using external method.
 */
 
 /* *** COMPRESSION *** */
 
 /*! FSE_optimalTableLog():
     dynamically downsize 'tableLog' when conditions are met.
     It saves CPU time, by using smaller tables, while preserving or even improving compression ratio.
     @return : recommended tableLog (necessarily <= 'maxTableLog') */
 FSE_PUBLIC_API unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue);
 
 /*! FSE_normalizeCount():
     normalize counts so that sum(count[]) == Power_of_2 (2^tableLog)
     'normalizedCounter' is a table of short, of minimum size (maxSymbolValue+1).
     @return : tableLog,
               or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_normalizeCount(short* normalizedCounter, unsigned tableLog,
                     const unsigned* count, size_t srcSize, unsigned maxSymbolValue);
 
 /*! FSE_NCountWriteBound():
     Provides the maximum possible size of an FSE normalized table, given 'maxSymbolValue' and 'tableLog'.
     Typically useful for allocation purpose. */
 FSE_PUBLIC_API size_t FSE_NCountWriteBound(unsigned maxSymbolValue, unsigned tableLog);
 
 /*! FSE_writeNCount():
     Compactly save 'normalizedCounter' into 'buffer'.
     @return : size of the compressed table,
               or an errorCode, which can be tested using FSE_isError(). */
 FSE_PUBLIC_API size_t FSE_writeNCount (void* buffer, size_t bufferSize,
                                  const short* normalizedCounter,
                                  unsigned maxSymbolValue, unsigned tableLog);
 
 /*! Constructor and Destructor of FSE_CTable.
     Note that FSE_CTable size depends on 'tableLog' and 'maxSymbolValue' */
 typedef unsigned FSE_CTable;   /* don't allocate that. It's only meant to be more restrictive than void* */
 FSE_PUBLIC_API FSE_CTable* FSE_createCTable (unsigned maxSymbolValue, unsigned tableLog);
 FSE_PUBLIC_API void        FSE_freeCTable (FSE_CTable* ct);
 
 /*! FSE_buildCTable():
     Builds `ct`, which must be already allocated, using FSE_createCTable().
     @return : 0, or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_buildCTable(FSE_CTable* ct, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
 
 /*! FSE_compress_usingCTable():
     Compress `src` using `ct` into `dst` which must be already allocated.
     @return : size of compressed data (<= `dstCapacity`),
               or 0 if compressed data could not fit into `dst`,
               or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_compress_usingCTable (void* dst, size_t dstCapacity, const void* src, size_t srcSize, const FSE_CTable* ct);
 
 /*!
 Tutorial :
 ----------
 The first step is to count all symbols. FSE_count() does this job very fast.
 Result will be saved into 'count', a table of unsigned int, which must be already allocated, and have 'maxSymbolValuePtr[0]+1' cells.
 'src' is a table of bytes of size 'srcSize'. All values within 'src' MUST be <= maxSymbolValuePtr[0]
 maxSymbolValuePtr[0] will be updated, with its real value (necessarily <= original value)
 FSE_count() will return the number of occurrence of the most frequent symbol.
 This can be used to know if there is a single symbol within 'src', and to quickly evaluate its compressibility.
 If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError()).
 
 The next step is to normalize the frequencies.
 FSE_normalizeCount() will ensure that sum of frequencies is == 2 ^'tableLog'.
 It also guarantees a minimum of 1 to any Symbol with frequency >= 1.
 You can use 'tableLog'==0 to mean "use default tableLog value".
 If you are unsure of which tableLog value to use, you can ask FSE_optimalTableLog(),
 which will provide the optimal valid tableLog given sourceSize, maxSymbolValue, and a user-defined maximum (0 means "default").
 
 The result of FSE_normalizeCount() will be saved into a table,
 called 'normalizedCounter', which is a table of signed short.
 'normalizedCounter' must be already allocated, and have at least 'maxSymbolValue+1' cells.
 The return value is tableLog if everything proceeded as expected.
 It is 0 if there is a single symbol within distribution.
 If there is an error (ex: invalid tableLog value), the function will return an ErrorCode (which can be tested using FSE_isError()).
 
 'normalizedCounter' can be saved in a compact manner to a memory area using FSE_writeNCount().
 'buffer' must be already allocated.
 For guaranteed success, buffer size must be at least FSE_headerBound().
 The result of the function is the number of bytes written into 'buffer'.
 If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError(); ex : buffer size too small).
 
 'normalizedCounter' can then be used to create the compression table 'CTable'.
 The space required by 'CTable' must be already allocated, using FSE_createCTable().
 You can then use FSE_buildCTable() to fill 'CTable'.
 If there is an error, both functions will return an ErrorCode (which can be tested using FSE_isError()).
 
 'CTable' can then be used to compress 'src', with FSE_compress_usingCTable().
 Similar to FSE_count(), the convention is that 'src' is assumed to be a table of char of size 'srcSize'
 The function returns the size of compressed data (without header), necessarily <= `dstCapacity`.
 If it returns '0', compressed data could not fit into 'dst'.
 If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError()).
 */
 
 
 /* *** DECOMPRESSION *** */
 
 /*! FSE_readNCount():
     Read compactly saved 'normalizedCounter' from 'rBuffer'.
     @return : size read from 'rBuffer',
               or an errorCode, which can be tested using FSE_isError().
               maxSymbolValuePtr[0] and tableLogPtr[0] will also be updated with their respective values */
 FSE_PUBLIC_API size_t FSE_readNCount (short* normalizedCounter,
                            unsigned* maxSymbolValuePtr, unsigned* tableLogPtr,
                            const void* rBuffer, size_t rBuffSize);
 
 /*! Constructor and Destructor of FSE_DTable.
     Note that its size depends on 'tableLog' */
 typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
 FSE_PUBLIC_API FSE_DTable* FSE_createDTable(unsigned tableLog);
 FSE_PUBLIC_API void        FSE_freeDTable(FSE_DTable* dt);
 
 /*! FSE_buildDTable():
     Builds 'dt', which must be already allocated, using FSE_createDTable().
     return : 0, or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_buildDTable (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
 
 /*! FSE_decompress_usingDTable():
     Decompress compressed source `cSrc` of size `cSrcSize` using `dt`
     into `dst` which must be already allocated.
     @return : size of regenerated data (necessarily <= `dstCapacity`),
               or an errorCode, which can be tested using FSE_isError() */
 FSE_PUBLIC_API size_t FSE_decompress_usingDTable(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, const FSE_DTable* dt);
 
 /*!
 Tutorial :
 ----------
 (Note : these functions only decompress FSE-compressed blocks.
  If block is uncompressed, use memcpy() instead
  If block is a single repeated byte, use memset() instead )
 
 The first step is to obtain the normalized frequencies of symbols.
 This can be performed by FSE_readNCount() if it was saved using FSE_writeNCount().
 'normalizedCounter' must be already allocated, and have at least 'maxSymbolValuePtr[0]+1' cells of signed short.
 In practice, that means it's necessary to know 'maxSymbolValue' beforehand,
 or size the table to handle worst case situations (typically 256).
 FSE_readNCount() will provide 'tableLog' and 'maxSymbolValue'.
 The result of FSE_readNCount() is the number of bytes read from 'rBuffer'.
 Note that 'rBufferSize' must be at least 4 bytes, even if useful information is less than that.
 If there is an error, the function will return an error code, which can be tested using FSE_isError().
 
 The next step is to build the decompression tables 'FSE_DTable' from 'normalizedCounter'.
 This is performed by the function FSE_buildDTable().
 The space required by 'FSE_DTable' must be already allocated using FSE_createDTable().
 If there is an error, the function will return an error code, which can be tested using FSE_isError().
 
 `FSE_DTable` can then be used to decompress `cSrc`, with FSE_decompress_usingDTable().
 `cSrcSize` must be strictly correct, otherwise decompression will fail.
 FSE_decompress_usingDTable() result will tell how many bytes were regenerated (<=`dstCapacity`).
 If there is an error, the function will return an error code, which can be tested using FSE_isError(). (ex: dst buffer too small)
 */
 
 #endif  /* FSE_H */
 
 #if defined(FSE_STATIC_LINKING_ONLY) && !defined(FSE_H_FSE_STATIC_LINKING_ONLY)
 #define FSE_H_FSE_STATIC_LINKING_ONLY
 
 /* *** Dependency *** */
 #include "bitstream.h"
 
 
 /* *****************************************
 *  Static allocation
 *******************************************/
 /* FSE buffer bounds */
 #define FSE_NCOUNTBOUND 512
-#define FSE_BLOCKBOUND(size) (size + (size>>7))
+#define FSE_BLOCKBOUND(size) (size + (size>>7) + 4 /* fse states */ + sizeof(size_t) /* bitContainer */)
 #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
 
 /* It is possible to statically allocate FSE CTable/DTable as a table of FSE_CTable/FSE_DTable using below macros */
 #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1< 12) ? (1 << (maxTableLog - 2)) : 1024) )
 size_t FSE_compress_wksp (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize);
 
 size_t FSE_buildCTable_raw (FSE_CTable* ct, unsigned nbBits);
 /**< build a fake FSE_CTable, designed for a flat distribution, where each symbol uses nbBits */
 
 size_t FSE_buildCTable_rle (FSE_CTable* ct, unsigned char symbolValue);
 /**< build a fake FSE_CTable, designed to compress always the same symbolValue */
 
 /* FSE_buildCTable_wksp() :
  * Same as FSE_buildCTable(), but using an externally allocated scratch buffer (`workSpace`).
  * `wkspSize` must be >= `(1<= BIT_DStream_completed
 
 When it's done, verify decompression is fully completed, by checking both DStream and the relevant states.
 Checking if DStream has reached its end is performed by :
     BIT_endOfDStream(&DStream);
 Check also the states. There might be some symbols left there, if some high probability ones (>50%) are possible.
     FSE_endOfDState(&DState);
 */
 
 
 /* *****************************************
 *  FSE unsafe API
 *******************************************/
 static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
 /* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */
 
 
 /* *****************************************
 *  Implementation of inlined functions
 *******************************************/
 typedef struct {
     int deltaFindState;
     U32 deltaNbBits;
 } FSE_symbolCompressionTransform; /* total 8 bytes */
 
 MEM_STATIC void FSE_initCState(FSE_CState_t* statePtr, const FSE_CTable* ct)
 {
     const void* ptr = ct;
     const U16* u16ptr = (const U16*) ptr;
     const U32 tableLog = MEM_read16(ptr);
     statePtr->value = (ptrdiff_t)1<stateTable = u16ptr+2;
     statePtr->symbolTT = ct + 1 + (tableLog ? (1<<(tableLog-1)) : 1);
     statePtr->stateLog = tableLog;
 }
 
 
 /*! FSE_initCState2() :
 *   Same as FSE_initCState(), but the first symbol to include (which will be the last to be read)
 *   uses the smallest state value possible, saving the cost of this symbol */
 MEM_STATIC void FSE_initCState2(FSE_CState_t* statePtr, const FSE_CTable* ct, U32 symbol)
 {
     FSE_initCState(statePtr, ct);
     {   const FSE_symbolCompressionTransform symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
         const U16* stateTable = (const U16*)(statePtr->stateTable);
         U32 nbBitsOut  = (U32)((symbolTT.deltaNbBits + (1<<15)) >> 16);
         statePtr->value = (nbBitsOut << 16) - symbolTT.deltaNbBits;
         statePtr->value = stateTable[(statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
     }
 }
 
 MEM_STATIC void FSE_encodeSymbol(BIT_CStream_t* bitC, FSE_CState_t* statePtr, unsigned symbol)
 {
     FSE_symbolCompressionTransform const symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
     const U16* const stateTable = (const U16*)(statePtr->stateTable);
     U32 const nbBitsOut  = (U32)((statePtr->value + symbolTT.deltaNbBits) >> 16);
     BIT_addBits(bitC, statePtr->value, nbBitsOut);
     statePtr->value = stateTable[ (statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
 }
 
 MEM_STATIC void FSE_flushCState(BIT_CStream_t* bitC, const FSE_CState_t* statePtr)
 {
     BIT_addBits(bitC, statePtr->value, statePtr->stateLog);
     BIT_flushBits(bitC);
 }
 
 
 /* FSE_getMaxNbBits() :
  * Approximate maximum cost of a symbol, in bits.
  * Fractional get rounded up (i.e : a symbol with a normalized frequency of 3 gives the same result as a frequency of 2)
  * note 1 : assume symbolValue is valid (<= maxSymbolValue)
  * note 2 : if freq[symbolValue]==0, @return a fake cost of tableLog+1 bits */
 MEM_STATIC U32 FSE_getMaxNbBits(const void* symbolTTPtr, U32 symbolValue)
 {
     const FSE_symbolCompressionTransform* symbolTT = (const FSE_symbolCompressionTransform*) symbolTTPtr;
     return (symbolTT[symbolValue].deltaNbBits + ((1<<16)-1)) >> 16;
 }
 
 /* FSE_bitCost() :
  * Approximate symbol cost, as fractional value, using fixed-point format (accuracyLog fractional bits)
  * note 1 : assume symbolValue is valid (<= maxSymbolValue)
  * note 2 : if freq[symbolValue]==0, @return a fake cost of tableLog+1 bits */
 MEM_STATIC U32 FSE_bitCost(const void* symbolTTPtr, U32 tableLog, U32 symbolValue, U32 accuracyLog)
 {
     const FSE_symbolCompressionTransform* symbolTT = (const FSE_symbolCompressionTransform*) symbolTTPtr;
     U32 const minNbBits = symbolTT[symbolValue].deltaNbBits >> 16;
     U32 const threshold = (minNbBits+1) << 16;
     assert(tableLog < 16);
     assert(accuracyLog < 31-tableLog);  /* ensure enough room for renormalization double shift */
     {   U32 const tableSize = 1 << tableLog;
         U32 const deltaFromThreshold = threshold - (symbolTT[symbolValue].deltaNbBits + tableSize);
         U32 const normalizedDeltaFromThreshold = (deltaFromThreshold << accuracyLog) >> tableLog;   /* linear interpolation (very approximate) */
         U32 const bitMultiplier = 1 << accuracyLog;
         assert(symbolTT[symbolValue].deltaNbBits + tableSize <= threshold);
         assert(normalizedDeltaFromThreshold <= bitMultiplier);
         return (minNbBits+1)*bitMultiplier - normalizedDeltaFromThreshold;
     }
 }
 
 
 /* ======    Decompression    ====== */
 
 typedef struct {
     U16 tableLog;
     U16 fastMode;
 } FSE_DTableHeader;   /* sizeof U32 */
 
 typedef struct
 {
     unsigned short newState;
     unsigned char  symbol;
     unsigned char  nbBits;
 } FSE_decode_t;   /* size == U32 */
 
 MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
 {
     const void* ptr = dt;
     const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr;
     DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
     BIT_reloadDStream(bitD);
     DStatePtr->table = dt + 1;
 }
 
 MEM_STATIC BYTE FSE_peekSymbol(const FSE_DState_t* DStatePtr)
 {
     FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     return DInfo.symbol;
 }
 
 MEM_STATIC void FSE_updateState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     U32 const nbBits = DInfo.nbBits;
     size_t const lowBits = BIT_readBits(bitD, nbBits);
     DStatePtr->state = DInfo.newState + lowBits;
 }
 
 MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     U32 const nbBits = DInfo.nbBits;
     BYTE const symbol = DInfo.symbol;
     size_t const lowBits = BIT_readBits(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 /*! FSE_decodeSymbolFast() :
     unsafe, only works if no symbol has a probability > 50% */
 MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     U32 const nbBits = DInfo.nbBits;
     BYTE const symbol = DInfo.symbol;
     size_t const lowBits = BIT_readBitsFast(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
 {
     return DStatePtr->state == 0;
 }
 
 
 
 #ifndef FSE_COMMONDEFS_ONLY
 
 /* **************************************************************
 *  Tuning parameters
 ****************************************************************/
 /*!MEMORY_USAGE :
 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 *  Increasing memory usage improves compression ratio
 *  Reduced memory usage can improve speed, due to cache effect
 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
 #ifndef FSE_MAX_MEMORY_USAGE
 #  define FSE_MAX_MEMORY_USAGE 14
 #endif
 #ifndef FSE_DEFAULT_MEMORY_USAGE
 #  define FSE_DEFAULT_MEMORY_USAGE 13
 #endif
 
 /*!FSE_MAX_SYMBOL_VALUE :
 *  Maximum symbol value authorized.
 *  Required for proper stack allocation */
 #ifndef FSE_MAX_SYMBOL_VALUE
 #  define FSE_MAX_SYMBOL_VALUE 255
 #endif
 
 /* **************************************************************
 *  template functions type & suffix
 ****************************************************************/
 #define FSE_FUNCTION_TYPE BYTE
 #define FSE_FUNCTION_EXTENSION
 #define FSE_DECODE_TYPE FSE_decode_t
 
 
 #endif   /* !FSE_COMMONDEFS_ONLY */
 
 
 /* ***************************************************************
 *  Constants
 *****************************************************************/
 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
 #define FSE_MAX_TABLESIZE (1U< FSE_TABLELOG_ABSOLUTE_MAX
 #  error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
 #endif
 
 #define FSE_TABLESTEP(tableSize) ((tableSize>>1) + (tableSize>>3) + 3)
 
 
 #endif /* FSE_STATIC_LINKING_ONLY */
 
 
 #if defined (__cplusplus)
 }
 #endif
Index: head/sys/contrib/zstd/lib/common/fse_decompress.c
===================================================================
--- head/sys/contrib/zstd/lib/common/fse_decompress.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/fse_decompress.c	(revision 354777)
@@ -1,309 +1,311 @@
 /* ******************************************************************
    FSE : Finite State Entropy decoder
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 
 /* **************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
 #include "bitstream.h"
 #include "compiler.h"
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 #include "error_private.h"
 
 
 /* **************************************************************
 *  Error Management
 ****************************************************************/
 #define FSE_isError ERR_isError
 #define FSE_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)   /* use only *after* variable declarations */
 
 /* check and forward error code */
+#ifndef CHECK_F
 #define CHECK_F(f) { size_t const e = f; if (FSE_isError(e)) return e; }
+#endif
 
 
 /* **************************************************************
 *  Templates
 ****************************************************************/
 /*
   designed to be included
   for type-specific functions (template emulation in C)
   Objective is to write these functions only once, for improved maintenance
 */
 
 /* safety checks */
 #ifndef FSE_FUNCTION_EXTENSION
 #  error "FSE_FUNCTION_EXTENSION must be defined"
 #endif
 #ifndef FSE_FUNCTION_TYPE
 #  error "FSE_FUNCTION_TYPE must be defined"
 #endif
 
 /* Function names */
 #define FSE_CAT(X,Y) X##Y
 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
 
 
 /* Function templates */
 FSE_DTable* FSE_createDTable (unsigned tableLog)
 {
     if (tableLog > FSE_TABLELOG_ABSOLUTE_MAX) tableLog = FSE_TABLELOG_ABSOLUTE_MAX;
     return (FSE_DTable*)malloc( FSE_DTABLE_SIZE_U32(tableLog) * sizeof (U32) );
 }
 
 void FSE_freeDTable (FSE_DTable* dt)
 {
     free(dt);
 }
 
 size_t FSE_buildDTable(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
 {
     void* const tdPtr = dt+1;   /* because *dt is unsigned, 32-bits aligned on 32-bits */
     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*) (tdPtr);
     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
 
     U32 const maxSV1 = maxSymbolValue + 1;
     U32 const tableSize = 1 << tableLog;
     U32 highThreshold = tableSize-1;
 
     /* Sanity Checks */
     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
 
     /* Init, lay down lowprob symbols */
     {   FSE_DTableHeader DTableH;
         DTableH.tableLog = (U16)tableLog;
         DTableH.fastMode = 1;
         {   S16 const largeLimit= (S16)(1 << (tableLog-1));
             U32 s;
             for (s=0; s= largeLimit) DTableH.fastMode=0;
                     symbolNext[s] = normalizedCounter[s];
         }   }   }
         memcpy(dt, &DTableH, sizeof(DTableH));
     }
 
     /* Spread symbols */
     {   U32 const tableMask = tableSize-1;
         U32 const step = FSE_TABLESTEP(tableSize);
         U32 s, position = 0;
         for (s=0; s highThreshold) position = (position + step) & tableMask;   /* lowprob area */
         }   }
         if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
     }
 
     /* Build Decoding table */
     {   U32 u;
         for (u=0; utableLog = 0;
     DTableH->fastMode = 0;
 
     cell->newState = 0;
     cell->symbol = symbolValue;
     cell->nbBits = 0;
 
     return 0;
 }
 
 
 size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     void* dPtr = dt + 1;
     FSE_decode_t* const dinfo = (FSE_decode_t*)dPtr;
     const unsigned tableSize = 1 << nbBits;
     const unsigned tableMask = tableSize - 1;
     const unsigned maxSV1 = tableMask+1;
     unsigned s;
 
     /* Sanity checks */
     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
 
     /* Build Decoding Table */
     DTableH->tableLog = (U16)nbBits;
     DTableH->fastMode = 1;
     for (s=0; s sizeof(bitD.bitContainer)*8)    /* This test must be static */
             BIT_reloadDStream(&bitD);
 
         op[1] = FSE_GETSYMBOL(&state2);
 
         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
 
         op[2] = FSE_GETSYMBOL(&state1);
 
         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             BIT_reloadDStream(&bitD);
 
         op[3] = FSE_GETSYMBOL(&state2);
     }
 
     /* tail */
     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
     while (1) {
         if (op>(omax-2)) return ERROR(dstSize_tooSmall);
         *op++ = FSE_GETSYMBOL(&state1);
         if (BIT_reloadDStream(&bitD)==BIT_DStream_overflow) {
             *op++ = FSE_GETSYMBOL(&state2);
             break;
         }
 
         if (op>(omax-2)) return ERROR(dstSize_tooSmall);
         *op++ = FSE_GETSYMBOL(&state2);
         if (BIT_reloadDStream(&bitD)==BIT_DStream_overflow) {
             *op++ = FSE_GETSYMBOL(&state1);
             break;
     }   }
 
     return op-ostart;
 }
 
 
 size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
                             const void* cSrc, size_t cSrcSize,
                             const FSE_DTable* dt)
 {
     const void* ptr = dt;
     const FSE_DTableHeader* DTableH = (const FSE_DTableHeader*)ptr;
     const U32 fastMode = DTableH->fastMode;
 
     /* select fast mode (static) */
     if (fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
 }
 
 
 size_t FSE_decompress_wksp(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, FSE_DTable* workSpace, unsigned maxLog)
 {
     const BYTE* const istart = (const BYTE*)cSrc;
     const BYTE* ip = istart;
     short counting[FSE_MAX_SYMBOL_VALUE+1];
     unsigned tableLog;
     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
 
     /* normal FSE decoding mode */
     size_t const NCountLength = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
     if (FSE_isError(NCountLength)) return NCountLength;
     //if (NCountLength >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size; supposed to be already checked in NCountLength, only remaining case : NCountLength==cSrcSize */
     if (tableLog > maxLog) return ERROR(tableLog_tooLarge);
     ip += NCountLength;
     cSrcSize -= NCountLength;
 
     CHECK_F( FSE_buildDTable (workSpace, counting, maxSymbolValue, tableLog) );
 
     return FSE_decompress_usingDTable (dst, dstCapacity, ip, cSrcSize, workSpace);   /* always return, even if it is an error code */
 }
 
 
 typedef FSE_DTable DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
 
 size_t FSE_decompress(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize)
 {
     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
     return FSE_decompress_wksp(dst, dstCapacity, cSrc, cSrcSize, dt, FSE_MAX_TABLELOG);
 }
 
 
 
 #endif   /* FSE_COMMONDEFS_ONLY */
Index: head/sys/contrib/zstd/lib/common/mem.h
===================================================================
--- head/sys/contrib/zstd/lib/common/mem.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/mem.h	(revision 354777)
@@ -1,380 +1,453 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef MEM_H_MODULE
 #define MEM_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /*-****************************************
 *  Dependencies
 ******************************************/
 #include      /* size_t, ptrdiff_t */
 #include      /* memcpy */
 
 
 /*-****************************************
 *  Compiler specifics
 ******************************************/
 #if defined(_MSC_VER)   /* Visual Studio */
 #   include   /* _byteswap_ulong */
 #   include   /* _byteswap_* */
 #endif
 #if defined(__GNUC__)
 #  define MEM_STATIC static __inline __attribute__((unused))
 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 #  define MEM_STATIC static inline
 #elif defined(_MSC_VER)
 #  define MEM_STATIC static __inline
 #else
 #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
 #endif
 
 #ifndef __has_builtin
 #  define __has_builtin(x) 0  /* compat. with non-clang compilers */
 #endif
 
 /* code only tested on 32 and 64 bits systems */
 #define MEM_STATIC_ASSERT(c)   { enum { MEM_static_assert = 1/(int)(!!(c)) }; }
 MEM_STATIC void MEM_check(void) { MEM_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); }
 
+/* detects whether we are being compiled under msan */
+#if defined (__has_feature)
+#  if __has_feature(memory_sanitizer)
+#    define MEMORY_SANITIZER 1
+#  endif
+#endif
 
+#if defined (MEMORY_SANITIZER)
+/* Not all platforms that support msan provide sanitizers/msan_interface.h.
+ * We therefore declare the functions we need ourselves, rather than trying to
+ * include the header file... */
+
+#include  /* intptr_t */
+
+/* Make memory region fully initialized (without changing its contents). */
+void __msan_unpoison(const volatile void *a, size_t size);
+
+/* Make memory region fully uninitialized (without changing its contents).
+   This is a legacy interface that does not update origin information. Use
+   __msan_allocated_memory() instead. */
+void __msan_poison(const volatile void *a, size_t size);
+
+/* Returns the offset of the first (at least partially) poisoned byte in the
+   memory range, or -1 if the whole range is good. */
+intptr_t __msan_test_shadow(const volatile void *x, size_t size);
+#endif
+
+/* detects whether we are being compiled under asan */
+#if defined (__has_feature)
+#  if __has_feature(address_sanitizer)
+#    define ADDRESS_SANITIZER 1
+#  endif
+#elif defined(__SANITIZE_ADDRESS__)
+#  define ADDRESS_SANITIZER 1
+#endif
+
+#if defined (ADDRESS_SANITIZER)
+/* Not all platforms that support asan provide sanitizers/asan_interface.h.
+ * We therefore declare the functions we need ourselves, rather than trying to
+ * include the header file... */
+
+/**
+ * Marks a memory region ([addr, addr+size)) as unaddressable.
+ *
+ * This memory must be previously allocated by your program. Instrumented
+ * code is forbidden from accessing addresses in this region until it is
+ * unpoisoned. This function is not guaranteed to poison the entire region -
+ * it could poison only a subregion of [addr, addr+size) due to ASan
+ * alignment restrictions.
+ *
+ * \note This function is not thread-safe because no two threads can poison or
+ * unpoison memory in the same memory region simultaneously.
+ *
+ * \param addr Start of memory region.
+ * \param size Size of memory region. */
+void __asan_poison_memory_region(void const volatile *addr, size_t size);
+
+/**
+ * Marks a memory region ([addr, addr+size)) as addressable.
+ *
+ * This memory must be previously allocated by your program. Accessing
+ * addresses in this region is allowed until this region is poisoned again.
+ * This function could unpoison a super-region of [addr, addr+size) due
+ * to ASan alignment restrictions.
+ *
+ * \note This function is not thread-safe because no two threads can
+ * poison or unpoison memory in the same memory region simultaneously.
+ *
+ * \param addr Start of memory region.
+ * \param size Size of memory region. */
+void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
+#endif
+
+
 /*-**************************************************************
 *  Basic Types
 *****************************************************************/
 #if  !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
 # include 
   typedef   uint8_t BYTE;
   typedef  uint16_t U16;
   typedef   int16_t S16;
   typedef  uint32_t U32;
   typedef   int32_t S32;
   typedef  uint64_t U64;
   typedef   int64_t S64;
 #else
 # include 
 #if CHAR_BIT != 8
 #  error "this implementation requires char to be exactly 8-bit type"
 #endif
   typedef unsigned char      BYTE;
 #if USHRT_MAX != 65535
 #  error "this implementation requires short to be exactly 16-bit type"
 #endif
   typedef unsigned short      U16;
   typedef   signed short      S16;
 #if UINT_MAX != 4294967295
 #  error "this implementation requires int to be exactly 32-bit type"
 #endif
   typedef unsigned int        U32;
   typedef   signed int        S32;
 /* note : there are no limits defined for long long type in C90.
  * limits exist in C99, however, in such case,  is preferred */
   typedef unsigned long long  U64;
   typedef   signed long long  S64;
 #endif
 
 
 /*-**************************************************************
 *  Memory I/O
 *****************************************************************/
 /* MEM_FORCE_MEMORY_ACCESS :
  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
  * The below switch allow to select different access method for improved performance.
  * Method 0 (default) : use `memcpy()`. Safe and portable.
  * Method 1 : `__packed` statement. It depends on compiler extension (i.e., not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method is portable but violate C standard.
  *            It can generate buggy code on targets depending on alignment.
  *            In some circumstances, it's the only known way to get the most performance (i.e. GCC + ARMv6)
  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define MEM_FORCE_MEMORY_ACCESS 2
-#  elif defined(__INTEL_COMPILER) || defined(__GNUC__)
+#  elif defined(__INTEL_COMPILER) || defined(__GNUC__) || defined(__ICCARM__)
 #    define MEM_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
 
 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; }
 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; }
 
 MEM_STATIC unsigned MEM_isLittleEndian(void)
 {
     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
     return one.c[0];
 }
 
 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
 
 /* violates C standard, by lying on structure alignment.
 Only use if no other choice to achieve best performance on target platform */
 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
 MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
 MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; }
 MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; }
 
 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
 #if defined(_MSC_VER) || (defined(__INTEL_COMPILER) && defined(WIN32))
     __pragma( pack(push, 1) )
     typedef struct { U16 v; } unalign16;
     typedef struct { U32 v; } unalign32;
     typedef struct { U64 v; } unalign64;
     typedef struct { size_t v; } unalignArch;
     __pragma( pack(pop) )
 #else
     typedef struct { U16 v; } __attribute__((packed)) unalign16;
     typedef struct { U32 v; } __attribute__((packed)) unalign32;
     typedef struct { U64 v; } __attribute__((packed)) unalign64;
     typedef struct { size_t v; } __attribute__((packed)) unalignArch;
 #endif
 
 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign16*)ptr)->v; }
 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign32*)ptr)->v; }
 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign64*)ptr)->v; }
 MEM_STATIC size_t MEM_readST(const void* ptr) { return ((const unalignArch*)ptr)->v; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign16*)memPtr)->v = value; }
 MEM_STATIC void MEM_write32(void* memPtr, U32 value) { ((unalign32*)memPtr)->v = value; }
 MEM_STATIC void MEM_write64(void* memPtr, U64 value) { ((unalign64*)memPtr)->v = value; }
 
 #else
 
 /* default method, safe and standard.
    can sometimes prove slower */
 
 MEM_STATIC U16 MEM_read16(const void* memPtr)
 {
     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC U32 MEM_read32(const void* memPtr)
 {
     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC U64 MEM_read64(const void* memPtr)
 {
     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC size_t MEM_readST(const void* memPtr)
 {
     size_t val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 MEM_STATIC void MEM_write32(void* memPtr, U32 value)
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 MEM_STATIC void MEM_write64(void* memPtr, U64 value)
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 #endif /* MEM_FORCE_MEMORY_ACCESS */
 
 MEM_STATIC U32 MEM_swap32(U32 in)
 {
 #if defined(_MSC_VER)     /* Visual Studio */
     return _byteswap_ulong(in);
 #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
   || (defined(__clang__) && __has_builtin(__builtin_bswap32))
     return __builtin_bswap32(in);
 #else
     return  ((in << 24) & 0xff000000 ) |
             ((in <<  8) & 0x00ff0000 ) |
             ((in >>  8) & 0x0000ff00 ) |
             ((in >> 24) & 0x000000ff );
 #endif
 }
 
 MEM_STATIC U64 MEM_swap64(U64 in)
 {
 #if defined(_MSC_VER)     /* Visual Studio */
     return _byteswap_uint64(in);
 #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
   || (defined(__clang__) && __has_builtin(__builtin_bswap64))
     return __builtin_bswap64(in);
 #else
     return  ((in << 56) & 0xff00000000000000ULL) |
             ((in << 40) & 0x00ff000000000000ULL) |
             ((in << 24) & 0x0000ff0000000000ULL) |
             ((in << 8)  & 0x000000ff00000000ULL) |
             ((in >> 8)  & 0x00000000ff000000ULL) |
             ((in >> 24) & 0x0000000000ff0000ULL) |
             ((in >> 40) & 0x000000000000ff00ULL) |
             ((in >> 56) & 0x00000000000000ffULL);
 #endif
 }
 
 MEM_STATIC size_t MEM_swapST(size_t in)
 {
     if (MEM_32bits())
         return (size_t)MEM_swap32((U32)in);
     else
         return (size_t)MEM_swap64((U64)in);
 }
 
 /*=== Little endian r/w ===*/
 
 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read16(memPtr);
     else {
         const BYTE* p = (const BYTE*)memPtr;
         return (U16)(p[0] + (p[1]<<8));
     }
 }
 
 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
 {
     if (MEM_isLittleEndian()) {
         MEM_write16(memPtr, val);
     } else {
         BYTE* p = (BYTE*)memPtr;
         p[0] = (BYTE)val;
         p[1] = (BYTE)(val>>8);
     }
 }
 
 MEM_STATIC U32 MEM_readLE24(const void* memPtr)
 {
     return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16);
 }
 
 MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val)
 {
     MEM_writeLE16(memPtr, (U16)val);
     ((BYTE*)memPtr)[2] = (BYTE)(val>>16);
 }
 
 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read32(memPtr);
     else
         return MEM_swap32(MEM_read32(memPtr));
 }
 
 MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32)
 {
     if (MEM_isLittleEndian())
         MEM_write32(memPtr, val32);
     else
         MEM_write32(memPtr, MEM_swap32(val32));
 }
 
 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read64(memPtr);
     else
         return MEM_swap64(MEM_read64(memPtr));
 }
 
 MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64)
 {
     if (MEM_isLittleEndian())
         MEM_write64(memPtr, val64);
     else
         MEM_write64(memPtr, MEM_swap64(val64));
 }
 
 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
 {
     if (MEM_32bits())
         return (size_t)MEM_readLE32(memPtr);
     else
         return (size_t)MEM_readLE64(memPtr);
 }
 
 MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val)
 {
     if (MEM_32bits())
         MEM_writeLE32(memPtr, (U32)val);
     else
         MEM_writeLE64(memPtr, (U64)val);
 }
 
 /*=== Big endian r/w ===*/
 
 MEM_STATIC U32 MEM_readBE32(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_swap32(MEM_read32(memPtr));
     else
         return MEM_read32(memPtr);
 }
 
 MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32)
 {
     if (MEM_isLittleEndian())
         MEM_write32(memPtr, MEM_swap32(val32));
     else
         MEM_write32(memPtr, val32);
 }
 
 MEM_STATIC U64 MEM_readBE64(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_swap64(MEM_read64(memPtr));
     else
         return MEM_read64(memPtr);
 }
 
 MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64)
 {
     if (MEM_isLittleEndian())
         MEM_write64(memPtr, MEM_swap64(val64));
     else
         MEM_write64(memPtr, val64);
 }
 
 MEM_STATIC size_t MEM_readBEST(const void* memPtr)
 {
     if (MEM_32bits())
         return (size_t)MEM_readBE32(memPtr);
     else
         return (size_t)MEM_readBE64(memPtr);
 }
 
 MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val)
 {
     if (MEM_32bits())
         MEM_writeBE32(memPtr, (U32)val);
     else
         MEM_writeBE64(memPtr, (U64)val);
 }
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* MEM_H_MODULE */
Index: head/sys/contrib/zstd/lib/common/pool.c
===================================================================
--- head/sys/contrib/zstd/lib/common/pool.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/pool.c	(revision 354777)
@@ -1,340 +1,344 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /* ======   Dependencies   ======= */
 #include     /* size_t */
 #include "debug.h"     /* assert */
 #include "zstd_internal.h"  /* ZSTD_malloc, ZSTD_free */
 #include "pool.h"
 
 /* ======   Compiler specifics   ====== */
 #if defined(_MSC_VER)
 #  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
 #endif
 
 
 #ifdef ZSTD_MULTITHREAD
 
 #include "threading.h"   /* pthread adaptation */
 
 /* A job is a function and an opaque argument */
 typedef struct POOL_job_s {
     POOL_function function;
     void *opaque;
 } POOL_job;
 
 struct POOL_ctx_s {
     ZSTD_customMem customMem;
     /* Keep track of the threads */
     ZSTD_pthread_t* threads;
     size_t threadCapacity;
     size_t threadLimit;
 
     /* The queue is a circular buffer */
     POOL_job *queue;
     size_t queueHead;
     size_t queueTail;
     size_t queueSize;
 
     /* The number of threads working on jobs */
     size_t numThreadsBusy;
     /* Indicates if the queue is empty */
     int queueEmpty;
 
     /* The mutex protects the queue */
     ZSTD_pthread_mutex_t queueMutex;
     /* Condition variable for pushers to wait on when the queue is full */
     ZSTD_pthread_cond_t queuePushCond;
     /* Condition variables for poppers to wait on when the queue is empty */
     ZSTD_pthread_cond_t queuePopCond;
     /* Indicates if the queue is shutting down */
     int shutdown;
 };
 
 /* POOL_thread() :
  * Work thread for the thread pool.
  * Waits for jobs and executes them.
  * @returns : NULL on failure else non-null.
  */
 static void* POOL_thread(void* opaque) {
     POOL_ctx* const ctx = (POOL_ctx*)opaque;
     if (!ctx) { return NULL; }
     for (;;) {
         /* Lock the mutex and wait for a non-empty queue or until shutdown */
         ZSTD_pthread_mutex_lock(&ctx->queueMutex);
 
         while ( ctx->queueEmpty
             || (ctx->numThreadsBusy >= ctx->threadLimit) ) {
             if (ctx->shutdown) {
                 /* even if !queueEmpty, (possible if numThreadsBusy >= threadLimit),
                  * a few threads will be shutdown while !queueEmpty,
                  * but enough threads will remain active to finish the queue */
                 ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
                 return opaque;
             }
             ZSTD_pthread_cond_wait(&ctx->queuePopCond, &ctx->queueMutex);
         }
         /* Pop a job off the queue */
         {   POOL_job const job = ctx->queue[ctx->queueHead];
             ctx->queueHead = (ctx->queueHead + 1) % ctx->queueSize;
             ctx->numThreadsBusy++;
             ctx->queueEmpty = ctx->queueHead == ctx->queueTail;
             /* Unlock the mutex, signal a pusher, and run the job */
             ZSTD_pthread_cond_signal(&ctx->queuePushCond);
             ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
 
             job.function(job.opaque);
 
             /* If the intended queue size was 0, signal after finishing job */
             ZSTD_pthread_mutex_lock(&ctx->queueMutex);
             ctx->numThreadsBusy--;
             if (ctx->queueSize == 1) {
                 ZSTD_pthread_cond_signal(&ctx->queuePushCond);
             }
             ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
         }
     }  /* for (;;) */
     assert(0);  /* Unreachable */
 }
 
 POOL_ctx* POOL_create(size_t numThreads, size_t queueSize) {
     return POOL_create_advanced(numThreads, queueSize, ZSTD_defaultCMem);
 }
 
 POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize,
                                ZSTD_customMem customMem) {
     POOL_ctx* ctx;
     /* Check parameters */
     if (!numThreads) { return NULL; }
     /* Allocate the context and zero initialize */
     ctx = (POOL_ctx*)ZSTD_calloc(sizeof(POOL_ctx), customMem);
     if (!ctx) { return NULL; }
     /* Initialize the job queue.
      * It needs one extra space since one space is wasted to differentiate
      * empty and full queues.
      */
     ctx->queueSize = queueSize + 1;
     ctx->queue = (POOL_job*)ZSTD_malloc(ctx->queueSize * sizeof(POOL_job), customMem);
     ctx->queueHead = 0;
     ctx->queueTail = 0;
     ctx->numThreadsBusy = 0;
     ctx->queueEmpty = 1;
-    (void)ZSTD_pthread_mutex_init(&ctx->queueMutex, NULL);
-    (void)ZSTD_pthread_cond_init(&ctx->queuePushCond, NULL);
-    (void)ZSTD_pthread_cond_init(&ctx->queuePopCond, NULL);
+    {
+        int error = 0;
+        error |= ZSTD_pthread_mutex_init(&ctx->queueMutex, NULL);
+        error |= ZSTD_pthread_cond_init(&ctx->queuePushCond, NULL);
+        error |= ZSTD_pthread_cond_init(&ctx->queuePopCond, NULL);
+        if (error) { POOL_free(ctx); return NULL; }
+    }
     ctx->shutdown = 0;
     /* Allocate space for the thread handles */
     ctx->threads = (ZSTD_pthread_t*)ZSTD_malloc(numThreads * sizeof(ZSTD_pthread_t), customMem);
     ctx->threadCapacity = 0;
     ctx->customMem = customMem;
     /* Check for errors */
     if (!ctx->threads || !ctx->queue) { POOL_free(ctx); return NULL; }
     /* Initialize the threads */
     {   size_t i;
         for (i = 0; i < numThreads; ++i) {
             if (ZSTD_pthread_create(&ctx->threads[i], NULL, &POOL_thread, ctx)) {
                 ctx->threadCapacity = i;
                 POOL_free(ctx);
                 return NULL;
         }   }
         ctx->threadCapacity = numThreads;
         ctx->threadLimit = numThreads;
     }
     return ctx;
 }
 
 /*! POOL_join() :
     Shutdown the queue, wake any sleeping threads, and join all of the threads.
 */
 static void POOL_join(POOL_ctx* ctx) {
     /* Shut down the queue */
     ZSTD_pthread_mutex_lock(&ctx->queueMutex);
     ctx->shutdown = 1;
     ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
     /* Wake up sleeping threads */
     ZSTD_pthread_cond_broadcast(&ctx->queuePushCond);
     ZSTD_pthread_cond_broadcast(&ctx->queuePopCond);
     /* Join all of the threads */
     {   size_t i;
         for (i = 0; i < ctx->threadCapacity; ++i) {
             ZSTD_pthread_join(ctx->threads[i], NULL);  /* note : could fail */
     }   }
 }
 
 void POOL_free(POOL_ctx *ctx) {
     if (!ctx) { return; }
     POOL_join(ctx);
     ZSTD_pthread_mutex_destroy(&ctx->queueMutex);
     ZSTD_pthread_cond_destroy(&ctx->queuePushCond);
     ZSTD_pthread_cond_destroy(&ctx->queuePopCond);
     ZSTD_free(ctx->queue, ctx->customMem);
     ZSTD_free(ctx->threads, ctx->customMem);
     ZSTD_free(ctx, ctx->customMem);
 }
 
 
 
 size_t POOL_sizeof(POOL_ctx *ctx) {
     if (ctx==NULL) return 0;  /* supports sizeof NULL */
     return sizeof(*ctx)
         + ctx->queueSize * sizeof(POOL_job)
         + ctx->threadCapacity * sizeof(ZSTD_pthread_t);
 }
 
 
 /* @return : 0 on success, 1 on error */
 static int POOL_resize_internal(POOL_ctx* ctx, size_t numThreads)
 {
     if (numThreads <= ctx->threadCapacity) {
         if (!numThreads) return 1;
         ctx->threadLimit = numThreads;
         return 0;
     }
     /* numThreads > threadCapacity */
     {   ZSTD_pthread_t* const threadPool = (ZSTD_pthread_t*)ZSTD_malloc(numThreads * sizeof(ZSTD_pthread_t), ctx->customMem);
         if (!threadPool) return 1;
         /* replace existing thread pool */
         memcpy(threadPool, ctx->threads, ctx->threadCapacity * sizeof(*threadPool));
         ZSTD_free(ctx->threads, ctx->customMem);
         ctx->threads = threadPool;
         /* Initialize additional threads */
         {   size_t threadId;
             for (threadId = ctx->threadCapacity; threadId < numThreads; ++threadId) {
                 if (ZSTD_pthread_create(&threadPool[threadId], NULL, &POOL_thread, ctx)) {
                     ctx->threadCapacity = threadId;
                     return 1;
             }   }
     }   }
     /* successfully expanded */
     ctx->threadCapacity = numThreads;
     ctx->threadLimit = numThreads;
     return 0;
 }
 
 /* @return : 0 on success, 1 on error */
 int POOL_resize(POOL_ctx* ctx, size_t numThreads)
 {
     int result;
     if (ctx==NULL) return 1;
     ZSTD_pthread_mutex_lock(&ctx->queueMutex);
     result = POOL_resize_internal(ctx, numThreads);
     ZSTD_pthread_cond_broadcast(&ctx->queuePopCond);
     ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
     return result;
 }
 
 /**
  * Returns 1 if the queue is full and 0 otherwise.
  *
  * When queueSize is 1 (pool was created with an intended queueSize of 0),
  * then a queue is empty if there is a thread free _and_ no job is waiting.
  */
 static int isQueueFull(POOL_ctx const* ctx) {
     if (ctx->queueSize > 1) {
         return ctx->queueHead == ((ctx->queueTail + 1) % ctx->queueSize);
     } else {
         return (ctx->numThreadsBusy == ctx->threadLimit) ||
                !ctx->queueEmpty;
     }
 }
 
 
 static void POOL_add_internal(POOL_ctx* ctx, POOL_function function, void *opaque)
 {
     POOL_job const job = {function, opaque};
     assert(ctx != NULL);
     if (ctx->shutdown) return;
 
     ctx->queueEmpty = 0;
     ctx->queue[ctx->queueTail] = job;
     ctx->queueTail = (ctx->queueTail + 1) % ctx->queueSize;
     ZSTD_pthread_cond_signal(&ctx->queuePopCond);
 }
 
 void POOL_add(POOL_ctx* ctx, POOL_function function, void* opaque)
 {
     assert(ctx != NULL);
     ZSTD_pthread_mutex_lock(&ctx->queueMutex);
     /* Wait until there is space in the queue for the new job */
     while (isQueueFull(ctx) && (!ctx->shutdown)) {
         ZSTD_pthread_cond_wait(&ctx->queuePushCond, &ctx->queueMutex);
     }
     POOL_add_internal(ctx, function, opaque);
     ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
 }
 
 
 int POOL_tryAdd(POOL_ctx* ctx, POOL_function function, void* opaque)
 {
     assert(ctx != NULL);
     ZSTD_pthread_mutex_lock(&ctx->queueMutex);
     if (isQueueFull(ctx)) {
         ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
         return 0;
     }
     POOL_add_internal(ctx, function, opaque);
     ZSTD_pthread_mutex_unlock(&ctx->queueMutex);
     return 1;
 }
 
 
 #else  /* ZSTD_MULTITHREAD  not defined */
 
 /* ========================== */
 /* No multi-threading support */
 /* ========================== */
 
 
 /* We don't need any data, but if it is empty, malloc() might return NULL. */
 struct POOL_ctx_s {
     int dummy;
 };
 static POOL_ctx g_ctx;
 
 POOL_ctx* POOL_create(size_t numThreads, size_t queueSize) {
     return POOL_create_advanced(numThreads, queueSize, ZSTD_defaultCMem);
 }
 
 POOL_ctx* POOL_create_advanced(size_t numThreads, size_t queueSize, ZSTD_customMem customMem) {
     (void)numThreads;
     (void)queueSize;
     (void)customMem;
     return &g_ctx;
 }
 
 void POOL_free(POOL_ctx* ctx) {
     assert(!ctx || ctx == &g_ctx);
     (void)ctx;
 }
 
 int POOL_resize(POOL_ctx* ctx, size_t numThreads) {
     (void)ctx; (void)numThreads;
     return 0;
 }
 
 void POOL_add(POOL_ctx* ctx, POOL_function function, void* opaque) {
     (void)ctx;
     function(opaque);
 }
 
 int POOL_tryAdd(POOL_ctx* ctx, POOL_function function, void* opaque) {
     (void)ctx;
     function(opaque);
     return 1;
 }
 
 size_t POOL_sizeof(POOL_ctx* ctx) {
     if (ctx==NULL) return 0;  /* supports sizeof NULL */
     assert(ctx == &g_ctx);
     return sizeof(*ctx);
 }
 
 #endif  /* ZSTD_MULTITHREAD */
Index: head/sys/contrib/zstd/lib/common/threading.c
===================================================================
--- head/sys/contrib/zstd/lib/common/threading.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/threading.c	(revision 354777)
@@ -1,75 +1,120 @@
 /**
  * Copyright (c) 2016 Tino Reichardt
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  *
  * You can contact the author at:
  * - zstdmt source repository: https://github.com/mcmilk/zstdmt
  */
 
 /**
  * This file will hold wrapper for systems, which do not support pthreads
  */
 
+#include "threading.h"
+
 /* create fake symbol to avoid empty translation unit warning */
 int g_ZSTD_threading_useless_symbol;
 
 #if defined(ZSTD_MULTITHREAD) && defined(_WIN32)
 
 /**
  * Windows minimalist Pthread Wrapper, based on :
  * http://www.cse.wustl.edu/~schmidt/win32-cv-1.html
  */
 
 
 /* ===  Dependencies  === */
 #include 
 #include 
-#include "threading.h"
 
 
 /* ===  Implementation  === */
 
 static unsigned __stdcall worker(void *arg)
 {
     ZSTD_pthread_t* const thread = (ZSTD_pthread_t*) arg;
     thread->arg = thread->start_routine(thread->arg);
     return 0;
 }
 
 int ZSTD_pthread_create(ZSTD_pthread_t* thread, const void* unused,
             void* (*start_routine) (void*), void* arg)
 {
     (void)unused;
     thread->arg = arg;
     thread->start_routine = start_routine;
     thread->handle = (HANDLE) _beginthreadex(NULL, 0, worker, thread, 0, NULL);
 
     if (!thread->handle)
         return errno;
     else
         return 0;
 }
 
 int ZSTD_pthread_join(ZSTD_pthread_t thread, void **value_ptr)
 {
     DWORD result;
 
     if (!thread.handle) return 0;
 
     result = WaitForSingleObject(thread.handle, INFINITE);
     switch (result) {
     case WAIT_OBJECT_0:
         if (value_ptr) *value_ptr = thread.arg;
         return 0;
     case WAIT_ABANDONED:
         return EINVAL;
     default:
         return GetLastError();
     }
 }
 
 #endif   /* ZSTD_MULTITHREAD */
+
+#if defined(ZSTD_MULTITHREAD) && DEBUGLEVEL >= 1 && !defined(_WIN32)
+
+#include 
+
+int ZSTD_pthread_mutex_init(ZSTD_pthread_mutex_t* mutex, pthread_mutexattr_t const* attr)
+{
+    *mutex = (pthread_mutex_t*)malloc(sizeof(pthread_mutex_t));
+    if (!*mutex)
+        return 1;
+    return pthread_mutex_init(*mutex, attr);
+}
+
+int ZSTD_pthread_mutex_destroy(ZSTD_pthread_mutex_t* mutex)
+{
+    if (!*mutex)
+        return 0;
+    {
+        int const ret = pthread_mutex_destroy(*mutex);
+        free(*mutex);
+        return ret;
+    }
+}
+
+int ZSTD_pthread_cond_init(ZSTD_pthread_cond_t* cond, pthread_condattr_t const* attr)
+{
+    *cond = (pthread_cond_t*)malloc(sizeof(pthread_cond_t));
+    if (!*cond)
+        return 1;
+    return pthread_cond_init(*cond, attr);
+}
+
+int ZSTD_pthread_cond_destroy(ZSTD_pthread_cond_t* cond)
+{
+    if (!*cond)
+        return 0;
+    {
+        int const ret = pthread_cond_destroy(*cond);
+        free(*cond);
+        return ret;
+    }
+}
+
+#endif
Index: head/sys/contrib/zstd/lib/common/threading.h
===================================================================
--- head/sys/contrib/zstd/lib/common/threading.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/threading.h	(revision 354777)
@@ -1,123 +1,154 @@
 /**
  * Copyright (c) 2016 Tino Reichardt
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  *
  * You can contact the author at:
  * - zstdmt source repository: https://github.com/mcmilk/zstdmt
  */
 
 #ifndef THREADING_H_938743
 #define THREADING_H_938743
 
+#include "debug.h"
+
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #if defined(ZSTD_MULTITHREAD) && defined(_WIN32)
 
 /**
  * Windows minimalist Pthread Wrapper, based on :
  * http://www.cse.wustl.edu/~schmidt/win32-cv-1.html
  */
 #ifdef WINVER
 #  undef WINVER
 #endif
 #define WINVER       0x0600
 
 #ifdef _WIN32_WINNT
 #  undef _WIN32_WINNT
 #endif
 #define _WIN32_WINNT 0x0600
 
 #ifndef WIN32_LEAN_AND_MEAN
 #  define WIN32_LEAN_AND_MEAN
 #endif
 
 #undef ERROR   /* reported already defined on VS 2015 (Rich Geldreich) */
 #include 
 #undef ERROR
 #define ERROR(name) ZSTD_ERROR(name)
 
 
 /* mutex */
 #define ZSTD_pthread_mutex_t           CRITICAL_SECTION
 #define ZSTD_pthread_mutex_init(a, b)  ((void)(b), InitializeCriticalSection((a)), 0)
 #define ZSTD_pthread_mutex_destroy(a)  DeleteCriticalSection((a))
 #define ZSTD_pthread_mutex_lock(a)     EnterCriticalSection((a))
 #define ZSTD_pthread_mutex_unlock(a)   LeaveCriticalSection((a))
 
 /* condition variable */
 #define ZSTD_pthread_cond_t             CONDITION_VARIABLE
 #define ZSTD_pthread_cond_init(a, b)    ((void)(b), InitializeConditionVariable((a)), 0)
 #define ZSTD_pthread_cond_destroy(a)    ((void)(a))
 #define ZSTD_pthread_cond_wait(a, b)    SleepConditionVariableCS((a), (b), INFINITE)
 #define ZSTD_pthread_cond_signal(a)     WakeConditionVariable((a))
 #define ZSTD_pthread_cond_broadcast(a)  WakeAllConditionVariable((a))
 
 /* ZSTD_pthread_create() and ZSTD_pthread_join() */
 typedef struct {
     HANDLE handle;
     void* (*start_routine)(void*);
     void* arg;
 } ZSTD_pthread_t;
 
 int ZSTD_pthread_create(ZSTD_pthread_t* thread, const void* unused,
                    void* (*start_routine) (void*), void* arg);
 
 int ZSTD_pthread_join(ZSTD_pthread_t thread, void** value_ptr);
 
 /**
  * add here more wrappers as required
  */
 
 
-#elif defined(ZSTD_MULTITHREAD)   /* posix assumed ; need a better detection method */
+#elif defined(ZSTD_MULTITHREAD)    /* posix assumed ; need a better detection method */
 /* ===   POSIX Systems   === */
 #  include 
 
+#if DEBUGLEVEL < 1
+
 #define ZSTD_pthread_mutex_t            pthread_mutex_t
 #define ZSTD_pthread_mutex_init(a, b)   pthread_mutex_init((a), (b))
 #define ZSTD_pthread_mutex_destroy(a)   pthread_mutex_destroy((a))
 #define ZSTD_pthread_mutex_lock(a)      pthread_mutex_lock((a))
 #define ZSTD_pthread_mutex_unlock(a)    pthread_mutex_unlock((a))
 
 #define ZSTD_pthread_cond_t             pthread_cond_t
 #define ZSTD_pthread_cond_init(a, b)    pthread_cond_init((a), (b))
 #define ZSTD_pthread_cond_destroy(a)    pthread_cond_destroy((a))
 #define ZSTD_pthread_cond_wait(a, b)    pthread_cond_wait((a), (b))
 #define ZSTD_pthread_cond_signal(a)     pthread_cond_signal((a))
 #define ZSTD_pthread_cond_broadcast(a)  pthread_cond_broadcast((a))
 
 #define ZSTD_pthread_t                  pthread_t
 #define ZSTD_pthread_create(a, b, c, d) pthread_create((a), (b), (c), (d))
 #define ZSTD_pthread_join(a, b)         pthread_join((a),(b))
+
+#else /* DEBUGLEVEL >= 1 */
+
+/* Debug implementation of threading.
+ * In this implementation we use pointers for mutexes and condition variables.
+ * This way, if we forget to init/destroy them the program will crash or ASAN
+ * will report leaks.
+ */
+
+#define ZSTD_pthread_mutex_t            pthread_mutex_t*
+int ZSTD_pthread_mutex_init(ZSTD_pthread_mutex_t* mutex, pthread_mutexattr_t const* attr);
+int ZSTD_pthread_mutex_destroy(ZSTD_pthread_mutex_t* mutex);
+#define ZSTD_pthread_mutex_lock(a)      pthread_mutex_lock(*(a))
+#define ZSTD_pthread_mutex_unlock(a)    pthread_mutex_unlock(*(a))
+
+#define ZSTD_pthread_cond_t             pthread_cond_t*
+int ZSTD_pthread_cond_init(ZSTD_pthread_cond_t* cond, pthread_condattr_t const* attr);
+int ZSTD_pthread_cond_destroy(ZSTD_pthread_cond_t* cond);
+#define ZSTD_pthread_cond_wait(a, b)    pthread_cond_wait(*(a), *(b))
+#define ZSTD_pthread_cond_signal(a)     pthread_cond_signal(*(a))
+#define ZSTD_pthread_cond_broadcast(a)  pthread_cond_broadcast(*(a))
+
+#define ZSTD_pthread_t                  pthread_t
+#define ZSTD_pthread_create(a, b, c, d) pthread_create((a), (b), (c), (d))
+#define ZSTD_pthread_join(a, b)         pthread_join((a),(b))
+
+#endif
 
 #else  /* ZSTD_MULTITHREAD not defined */
 /* No multithreading support */
 
 typedef int ZSTD_pthread_mutex_t;
 #define ZSTD_pthread_mutex_init(a, b)   ((void)(a), (void)(b), 0)
 #define ZSTD_pthread_mutex_destroy(a)   ((void)(a))
 #define ZSTD_pthread_mutex_lock(a)      ((void)(a))
 #define ZSTD_pthread_mutex_unlock(a)    ((void)(a))
 
 typedef int ZSTD_pthread_cond_t;
 #define ZSTD_pthread_cond_init(a, b)    ((void)(a), (void)(b), 0)
 #define ZSTD_pthread_cond_destroy(a)    ((void)(a))
 #define ZSTD_pthread_cond_wait(a, b)    ((void)(a), (void)(b))
 #define ZSTD_pthread_cond_signal(a)     ((void)(a))
 #define ZSTD_pthread_cond_broadcast(a)  ((void)(a))
 
 /* do not use ZSTD_pthread_t */
 
 #endif /* ZSTD_MULTITHREAD */
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* THREADING_H_938743 */
Index: head/sys/contrib/zstd/lib/common/xxhash.c
===================================================================
--- head/sys/contrib/zstd/lib/common/xxhash.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/xxhash.c	(revision 354777)
@@ -1,876 +1,882 @@
 /*
 *  xxHash - Fast Hash algorithm
 *  Copyright (C) 2012-2016, Yann Collet
 *
 *  BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are
 *  met:
 *
 *  * Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above
 *  copyright notice, this list of conditions and the following disclaimer
 *  in the documentation and/or other materials provided with the
 *  distribution.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You can contact the author at :
 *  - xxHash homepage: http://www.xxhash.com
 *  - xxHash source repository : https://github.com/Cyan4973/xxHash
 */
 
 
 /* *************************************
 *  Tuning parameters
 ***************************************/
 /*!XXH_FORCE_MEMORY_ACCESS :
  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
  * The below switch allow to select different access method for improved performance.
  * Method 0 (default) : use `memcpy()`. Safe and portable.
  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method doesn't depend on compiler but violate C standard.
  *            It can generate buggy code on targets which do not support unaligned memory accesses.
  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
  * See http://stackoverflow.com/a/32095106/646947 for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
 #ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define XXH_FORCE_MEMORY_ACCESS 2
 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
-  (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
+  (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) )) || \
+  defined(__ICCARM__)
 #    define XXH_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
 
 /*!XXH_ACCEPT_NULL_INPUT_POINTER :
  * If the input pointer is a null pointer, xxHash default behavior is to trigger a memory access error, since it is a bad pointer.
  * When this option is enabled, xxHash output for null input pointers will be the same as a null-length input.
  * By default, this option is disabled. To enable it, uncomment below define :
  */
 /* #define XXH_ACCEPT_NULL_INPUT_POINTER 1 */
 
 /*!XXH_FORCE_NATIVE_FORMAT :
  * By default, xxHash library provides endian-independent Hash values, based on little-endian convention.
  * Results are therefore identical for little-endian and big-endian CPU.
  * This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format.
  * Should endian-independence be of no importance for your application, you may set the #define below to 1,
  * to improve speed for Big-endian CPU.
  * This option has no impact on Little_Endian CPU.
  */
 #ifndef XXH_FORCE_NATIVE_FORMAT   /* can be defined externally */
 #  define XXH_FORCE_NATIVE_FORMAT 0
 #endif
 
 /*!XXH_FORCE_ALIGN_CHECK :
  * This is a minor performance trick, only useful with lots of very small keys.
  * It means : check for aligned/unaligned input.
  * The check costs one initial branch per hash; set to 0 when the input data
  * is guaranteed to be aligned.
  */
 #ifndef XXH_FORCE_ALIGN_CHECK /* can be defined externally */
 #  if defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64)
 #    define XXH_FORCE_ALIGN_CHECK 0
 #  else
 #    define XXH_FORCE_ALIGN_CHECK 1
 #  endif
 #endif
 
 
 /* *************************************
 *  Includes & Memory related functions
 ***************************************/
 /* Modify the local functions below should you wish to use some other memory routines */
 /* for malloc(), free() */
 #include 
 #include      /* size_t */
 static void* XXH_malloc(size_t s) { return malloc(s); }
 static void  XXH_free  (void* p)  { free(p); }
 /* for memcpy() */
 #include 
 static void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); }
 
 #ifndef XXH_STATIC_LINKING_ONLY
 #  define XXH_STATIC_LINKING_ONLY
 #endif
 #include "xxhash.h"
 
 
 /* *************************************
 *  Compiler Specific Options
 ***************************************/
 #if defined (__GNUC__) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 #  define INLINE_KEYWORD inline
 #else
 #  define INLINE_KEYWORD
 #endif
 
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__ICCARM__)
 #  define FORCE_INLINE_ATTR __attribute__((always_inline))
 #elif defined(_MSC_VER)
 #  define FORCE_INLINE_ATTR __forceinline
 #else
 #  define FORCE_INLINE_ATTR
 #endif
 
 #define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR
 
 
 #ifdef _MSC_VER
 #  pragma warning(disable : 4127)      /* disable: C4127: conditional expression is constant */
 #endif
 
 
 /* *************************************
 *  Basic Types
 ***************************************/
 #ifndef MEM_MODULE
 # define MEM_MODULE
 # if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
 #   include 
     typedef uint8_t  BYTE;
     typedef uint16_t U16;
     typedef uint32_t U32;
     typedef  int32_t S32;
     typedef uint64_t U64;
 #  else
     typedef unsigned char      BYTE;
     typedef unsigned short     U16;
     typedef unsigned int       U32;
     typedef   signed int       S32;
     typedef unsigned long long U64;   /* if your compiler doesn't support unsigned long long, replace by another 64-bit type here. Note that xxhash.h will also need to be updated. */
 #  endif
 #endif
 
 
 #if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))
 
 /* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
 static U32 XXH_read32(const void* memPtr) { return *(const U32*) memPtr; }
 static U64 XXH_read64(const void* memPtr) { return *(const U64*) memPtr; }
 
 #elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
 typedef union { U32 u32; U64 u64; } __attribute__((packed)) unalign;
 
 static U32 XXH_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
 static U64 XXH_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
 
 #else
 
 /* portable and safe solution. Generally efficient.
  * see : http://stackoverflow.com/a/32095106/646947
  */
 
 static U32 XXH_read32(const void* memPtr)
 {
     U32 val;
     memcpy(&val, memPtr, sizeof(val));
     return val;
 }
 
 static U64 XXH_read64(const void* memPtr)
 {
     U64 val;
     memcpy(&val, memPtr, sizeof(val));
     return val;
 }
 
 #endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */
 
 
 /* ****************************************
 *  Compiler-specific Functions and Macros
 ******************************************/
 #define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
 
 /* Note : although _rotl exists for minGW (GCC under windows), performance seems poor */
 #if defined(_MSC_VER)
 #  define XXH_rotl32(x,r) _rotl(x,r)
 #  define XXH_rotl64(x,r) _rotl64(x,r)
 #else
+#if defined(__ICCARM__)
+#  include 
+#  define XXH_rotl32(x,r) __ROR(x,(32 - r))
+#else
 #  define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r)))
+#endif
 #  define XXH_rotl64(x,r) ((x << r) | (x >> (64 - r)))
 #endif
 
 #if defined(_MSC_VER)     /* Visual Studio */
 #  define XXH_swap32 _byteswap_ulong
 #  define XXH_swap64 _byteswap_uint64
 #elif GCC_VERSION >= 403
 #  define XXH_swap32 __builtin_bswap32
 #  define XXH_swap64 __builtin_bswap64
 #else
 static U32 XXH_swap32 (U32 x)
 {
     return  ((x << 24) & 0xff000000 ) |
             ((x <<  8) & 0x00ff0000 ) |
             ((x >>  8) & 0x0000ff00 ) |
             ((x >> 24) & 0x000000ff );
 }
 static U64 XXH_swap64 (U64 x)
 {
     return  ((x << 56) & 0xff00000000000000ULL) |
             ((x << 40) & 0x00ff000000000000ULL) |
             ((x << 24) & 0x0000ff0000000000ULL) |
             ((x << 8)  & 0x000000ff00000000ULL) |
             ((x >> 8)  & 0x00000000ff000000ULL) |
             ((x >> 24) & 0x0000000000ff0000ULL) |
             ((x >> 40) & 0x000000000000ff00ULL) |
             ((x >> 56) & 0x00000000000000ffULL);
 }
 #endif
 
 
 /* *************************************
 *  Architecture Macros
 ***************************************/
 typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess;
 
 /* XXH_CPU_LITTLE_ENDIAN can be defined externally, for example on the compiler command line */
 #ifndef XXH_CPU_LITTLE_ENDIAN
     static const int g_one = 1;
 #   define XXH_CPU_LITTLE_ENDIAN   (*(const char*)(&g_one))
 #endif
 
 
 /* ***************************
 *  Memory reads
 *****************************/
 typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment;
 
 FORCE_INLINE_TEMPLATE U32 XXH_readLE32_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
 {
     if (align==XXH_unaligned)
         return endian==XXH_littleEndian ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
     else
         return endian==XXH_littleEndian ? *(const U32*)ptr : XXH_swap32(*(const U32*)ptr);
 }
 
 FORCE_INLINE_TEMPLATE U32 XXH_readLE32(const void* ptr, XXH_endianess endian)
 {
     return XXH_readLE32_align(ptr, endian, XXH_unaligned);
 }
 
 static U32 XXH_readBE32(const void* ptr)
 {
     return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
 }
 
 FORCE_INLINE_TEMPLATE U64 XXH_readLE64_align(const void* ptr, XXH_endianess endian, XXH_alignment align)
 {
     if (align==XXH_unaligned)
         return endian==XXH_littleEndian ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
     else
         return endian==XXH_littleEndian ? *(const U64*)ptr : XXH_swap64(*(const U64*)ptr);
 }
 
 FORCE_INLINE_TEMPLATE U64 XXH_readLE64(const void* ptr, XXH_endianess endian)
 {
     return XXH_readLE64_align(ptr, endian, XXH_unaligned);
 }
 
 static U64 XXH_readBE64(const void* ptr)
 {
     return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
 }
 
 
 /* *************************************
 *  Macros
 ***************************************/
 #define XXH_STATIC_ASSERT(c)   { enum { XXH_static_assert = 1/(int)(!!(c)) }; }    /* use only *after* variable declarations */
 
 
 /* *************************************
 *  Constants
 ***************************************/
 static const U32 PRIME32_1 = 2654435761U;
 static const U32 PRIME32_2 = 2246822519U;
 static const U32 PRIME32_3 = 3266489917U;
 static const U32 PRIME32_4 =  668265263U;
 static const U32 PRIME32_5 =  374761393U;
 
 static const U64 PRIME64_1 = 11400714785074694791ULL;
 static const U64 PRIME64_2 = 14029467366897019727ULL;
 static const U64 PRIME64_3 =  1609587929392839161ULL;
 static const U64 PRIME64_4 =  9650029242287828579ULL;
 static const U64 PRIME64_5 =  2870177450012600261ULL;
 
 XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }
 
 
 /* **************************
 *  Utils
 ****************************/
 XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* restrict dstState, const XXH32_state_t* restrict srcState)
 {
     memcpy(dstState, srcState, sizeof(*dstState));
 }
 
 XXH_PUBLIC_API void XXH64_copyState(XXH64_state_t* restrict dstState, const XXH64_state_t* restrict srcState)
 {
     memcpy(dstState, srcState, sizeof(*dstState));
 }
 
 
 /* ***************************
 *  Simple Hash Functions
 *****************************/
 
 static U32 XXH32_round(U32 seed, U32 input)
 {
     seed += input * PRIME32_2;
     seed  = XXH_rotl32(seed, 13);
     seed *= PRIME32_1;
     return seed;
 }
 
 FORCE_INLINE_TEMPLATE U32 XXH32_endian_align(const void* input, size_t len, U32 seed, XXH_endianess endian, XXH_alignment align)
 {
     const BYTE* p = (const BYTE*)input;
     const BYTE* bEnd = p + len;
     U32 h32;
 #define XXH_get32bits(p) XXH_readLE32_align(p, endian, align)
 
 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
     if (p==NULL) {
         len=0;
         bEnd=p=(const BYTE*)(size_t)16;
     }
 #endif
 
     if (len>=16) {
         const BYTE* const limit = bEnd - 16;
         U32 v1 = seed + PRIME32_1 + PRIME32_2;
         U32 v2 = seed + PRIME32_2;
         U32 v3 = seed + 0;
         U32 v4 = seed - PRIME32_1;
 
         do {
             v1 = XXH32_round(v1, XXH_get32bits(p)); p+=4;
             v2 = XXH32_round(v2, XXH_get32bits(p)); p+=4;
             v3 = XXH32_round(v3, XXH_get32bits(p)); p+=4;
             v4 = XXH32_round(v4, XXH_get32bits(p)); p+=4;
         } while (p<=limit);
 
         h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
     } else {
         h32  = seed + PRIME32_5;
     }
 
     h32 += (U32) len;
 
     while (p+4<=bEnd) {
         h32 += XXH_get32bits(p) * PRIME32_3;
         h32  = XXH_rotl32(h32, 17) * PRIME32_4 ;
         p+=4;
     }
 
     while (p> 15;
     h32 *= PRIME32_2;
     h32 ^= h32 >> 13;
     h32 *= PRIME32_3;
     h32 ^= h32 >> 16;
 
     return h32;
 }
 
 
 XXH_PUBLIC_API unsigned int XXH32 (const void* input, size_t len, unsigned int seed)
 {
 #if 0
     /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
     XXH32_CREATESTATE_STATIC(state);
     XXH32_reset(state, seed);
     XXH32_update(state, input, len);
     return XXH32_digest(state);
 #else
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if (XXH_FORCE_ALIGN_CHECK) {
         if ((((size_t)input) & 3) == 0) {   /* Input is 4-bytes aligned, leverage the speed benefit */
             if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
                 return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
             else
                 return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
     }   }
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
     else
         return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
 #endif
 }
 
 
 static U64 XXH64_round(U64 acc, U64 input)
 {
     acc += input * PRIME64_2;
     acc  = XXH_rotl64(acc, 31);
     acc *= PRIME64_1;
     return acc;
 }
 
 static U64 XXH64_mergeRound(U64 acc, U64 val)
 {
     val  = XXH64_round(0, val);
     acc ^= val;
     acc  = acc * PRIME64_1 + PRIME64_4;
     return acc;
 }
 
 FORCE_INLINE_TEMPLATE U64 XXH64_endian_align(const void* input, size_t len, U64 seed, XXH_endianess endian, XXH_alignment align)
 {
     const BYTE* p = (const BYTE*)input;
     const BYTE* const bEnd = p + len;
     U64 h64;
 #define XXH_get64bits(p) XXH_readLE64_align(p, endian, align)
 
 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
     if (p==NULL) {
         len=0;
         bEnd=p=(const BYTE*)(size_t)32;
     }
 #endif
 
     if (len>=32) {
         const BYTE* const limit = bEnd - 32;
         U64 v1 = seed + PRIME64_1 + PRIME64_2;
         U64 v2 = seed + PRIME64_2;
         U64 v3 = seed + 0;
         U64 v4 = seed - PRIME64_1;
 
         do {
             v1 = XXH64_round(v1, XXH_get64bits(p)); p+=8;
             v2 = XXH64_round(v2, XXH_get64bits(p)); p+=8;
             v3 = XXH64_round(v3, XXH_get64bits(p)); p+=8;
             v4 = XXH64_round(v4, XXH_get64bits(p)); p+=8;
         } while (p<=limit);
 
         h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
         h64 = XXH64_mergeRound(h64, v1);
         h64 = XXH64_mergeRound(h64, v2);
         h64 = XXH64_mergeRound(h64, v3);
         h64 = XXH64_mergeRound(h64, v4);
 
     } else {
         h64  = seed + PRIME64_5;
     }
 
     h64 += (U64) len;
 
     while (p+8<=bEnd) {
         U64 const k1 = XXH64_round(0, XXH_get64bits(p));
         h64 ^= k1;
         h64  = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4;
         p+=8;
     }
 
     if (p+4<=bEnd) {
         h64 ^= (U64)(XXH_get32bits(p)) * PRIME64_1;
         h64 = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
         p+=4;
     }
 
     while (p> 33;
     h64 *= PRIME64_2;
     h64 ^= h64 >> 29;
     h64 *= PRIME64_3;
     h64 ^= h64 >> 32;
 
     return h64;
 }
 
 
 XXH_PUBLIC_API unsigned long long XXH64 (const void* input, size_t len, unsigned long long seed)
 {
 #if 0
     /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
     XXH64_CREATESTATE_STATIC(state);
     XXH64_reset(state, seed);
     XXH64_update(state, input, len);
     return XXH64_digest(state);
 #else
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if (XXH_FORCE_ALIGN_CHECK) {
         if ((((size_t)input) & 7)==0) {  /* Input is aligned, let's leverage the speed advantage */
             if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
                 return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned);
             else
                 return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned);
     }   }
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH64_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned);
     else
         return XXH64_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned);
 #endif
 }
 
 
 /* **************************************************
 *  Advanced Hash Functions
 ****************************************************/
 
 XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
 {
     return (XXH32_state_t*)XXH_malloc(sizeof(XXH32_state_t));
 }
 XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
 {
     XXH_free(statePtr);
     return XXH_OK;
 }
 
 XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
 {
     return (XXH64_state_t*)XXH_malloc(sizeof(XXH64_state_t));
 }
 XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
 {
     XXH_free(statePtr);
     return XXH_OK;
 }
 
 
 /*** Hash feed ***/
 
 XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, unsigned int seed)
 {
     XXH32_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
     memset(&state, 0, sizeof(state)-4);   /* do not write into reserved, for future removal */
     state.v1 = seed + PRIME32_1 + PRIME32_2;
     state.v2 = seed + PRIME32_2;
     state.v3 = seed + 0;
     state.v4 = seed - PRIME32_1;
     memcpy(statePtr, &state, sizeof(state));
     return XXH_OK;
 }
 
 
 XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, unsigned long long seed)
 {
     XXH64_state_t state;   /* using a local state to memcpy() in order to avoid strict-aliasing warnings */
     memset(&state, 0, sizeof(state)-8);   /* do not write into reserved, for future removal */
     state.v1 = seed + PRIME64_1 + PRIME64_2;
     state.v2 = seed + PRIME64_2;
     state.v3 = seed + 0;
     state.v4 = seed - PRIME64_1;
     memcpy(statePtr, &state, sizeof(state));
     return XXH_OK;
 }
 
 
 FORCE_INLINE_TEMPLATE XXH_errorcode XXH32_update_endian (XXH32_state_t* state, const void* input, size_t len, XXH_endianess endian)
 {
     const BYTE* p = (const BYTE*)input;
     const BYTE* const bEnd = p + len;
 
 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
     if (input==NULL) return XXH_ERROR;
 #endif
 
     state->total_len_32 += (unsigned)len;
     state->large_len |= (len>=16) | (state->total_len_32>=16);
 
     if (state->memsize + len < 16)  {   /* fill in tmp buffer */
         XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, len);
         state->memsize += (unsigned)len;
         return XXH_OK;
     }
 
     if (state->memsize) {   /* some data left from previous update */
         XXH_memcpy((BYTE*)(state->mem32) + state->memsize, input, 16-state->memsize);
         {   const U32* p32 = state->mem32;
             state->v1 = XXH32_round(state->v1, XXH_readLE32(p32, endian)); p32++;
             state->v2 = XXH32_round(state->v2, XXH_readLE32(p32, endian)); p32++;
             state->v3 = XXH32_round(state->v3, XXH_readLE32(p32, endian)); p32++;
             state->v4 = XXH32_round(state->v4, XXH_readLE32(p32, endian)); p32++;
         }
         p += 16-state->memsize;
         state->memsize = 0;
     }
 
     if (p <= bEnd-16) {
         const BYTE* const limit = bEnd - 16;
         U32 v1 = state->v1;
         U32 v2 = state->v2;
         U32 v3 = state->v3;
         U32 v4 = state->v4;
 
         do {
             v1 = XXH32_round(v1, XXH_readLE32(p, endian)); p+=4;
             v2 = XXH32_round(v2, XXH_readLE32(p, endian)); p+=4;
             v3 = XXH32_round(v3, XXH_readLE32(p, endian)); p+=4;
             v4 = XXH32_round(v4, XXH_readLE32(p, endian)); p+=4;
         } while (p<=limit);
 
         state->v1 = v1;
         state->v2 = v2;
         state->v3 = v3;
         state->v4 = v4;
     }
 
     if (p < bEnd) {
         XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
         state->memsize = (unsigned)(bEnd-p);
     }
 
     return XXH_OK;
 }
 
 XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* state_in, const void* input, size_t len)
 {
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH32_update_endian(state_in, input, len, XXH_littleEndian);
     else
         return XXH32_update_endian(state_in, input, len, XXH_bigEndian);
 }
 
 
 
 FORCE_INLINE_TEMPLATE U32 XXH32_digest_endian (const XXH32_state_t* state, XXH_endianess endian)
 {
     const BYTE * p = (const BYTE*)state->mem32;
     const BYTE* const bEnd = (const BYTE*)(state->mem32) + state->memsize;
     U32 h32;
 
     if (state->large_len) {
         h32 = XXH_rotl32(state->v1, 1) + XXH_rotl32(state->v2, 7) + XXH_rotl32(state->v3, 12) + XXH_rotl32(state->v4, 18);
     } else {
         h32 = state->v3 /* == seed */ + PRIME32_5;
     }
 
     h32 += state->total_len_32;
 
     while (p+4<=bEnd) {
         h32 += XXH_readLE32(p, endian) * PRIME32_3;
         h32  = XXH_rotl32(h32, 17) * PRIME32_4;
         p+=4;
     }
 
     while (p> 15;
     h32 *= PRIME32_2;
     h32 ^= h32 >> 13;
     h32 *= PRIME32_3;
     h32 ^= h32 >> 16;
 
     return h32;
 }
 
 
 XXH_PUBLIC_API unsigned int XXH32_digest (const XXH32_state_t* state_in)
 {
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH32_digest_endian(state_in, XXH_littleEndian);
     else
         return XXH32_digest_endian(state_in, XXH_bigEndian);
 }
 
 
 
 /* **** XXH64 **** */
 
 FORCE_INLINE_TEMPLATE XXH_errorcode XXH64_update_endian (XXH64_state_t* state, const void* input, size_t len, XXH_endianess endian)
 {
     const BYTE* p = (const BYTE*)input;
     const BYTE* const bEnd = p + len;
 
 #ifdef XXH_ACCEPT_NULL_INPUT_POINTER
     if (input==NULL) return XXH_ERROR;
 #endif
 
     state->total_len += len;
 
     if (state->memsize + len < 32) {  /* fill in tmp buffer */
         XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, len);
         state->memsize += (U32)len;
         return XXH_OK;
     }
 
     if (state->memsize) {   /* tmp buffer is full */
         XXH_memcpy(((BYTE*)state->mem64) + state->memsize, input, 32-state->memsize);
         state->v1 = XXH64_round(state->v1, XXH_readLE64(state->mem64+0, endian));
         state->v2 = XXH64_round(state->v2, XXH_readLE64(state->mem64+1, endian));
         state->v3 = XXH64_round(state->v3, XXH_readLE64(state->mem64+2, endian));
         state->v4 = XXH64_round(state->v4, XXH_readLE64(state->mem64+3, endian));
         p += 32-state->memsize;
         state->memsize = 0;
     }
 
     if (p+32 <= bEnd) {
         const BYTE* const limit = bEnd - 32;
         U64 v1 = state->v1;
         U64 v2 = state->v2;
         U64 v3 = state->v3;
         U64 v4 = state->v4;
 
         do {
             v1 = XXH64_round(v1, XXH_readLE64(p, endian)); p+=8;
             v2 = XXH64_round(v2, XXH_readLE64(p, endian)); p+=8;
             v3 = XXH64_round(v3, XXH_readLE64(p, endian)); p+=8;
             v4 = XXH64_round(v4, XXH_readLE64(p, endian)); p+=8;
         } while (p<=limit);
 
         state->v1 = v1;
         state->v2 = v2;
         state->v3 = v3;
         state->v4 = v4;
     }
 
     if (p < bEnd) {
         XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
         state->memsize = (unsigned)(bEnd-p);
     }
 
     return XXH_OK;
 }
 
 XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH64_state_t* state_in, const void* input, size_t len)
 {
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH64_update_endian(state_in, input, len, XXH_littleEndian);
     else
         return XXH64_update_endian(state_in, input, len, XXH_bigEndian);
 }
 
 
 
 FORCE_INLINE_TEMPLATE U64 XXH64_digest_endian (const XXH64_state_t* state, XXH_endianess endian)
 {
     const BYTE * p = (const BYTE*)state->mem64;
     const BYTE* const bEnd = (const BYTE*)state->mem64 + state->memsize;
     U64 h64;
 
     if (state->total_len >= 32) {
         U64 const v1 = state->v1;
         U64 const v2 = state->v2;
         U64 const v3 = state->v3;
         U64 const v4 = state->v4;
 
         h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
         h64 = XXH64_mergeRound(h64, v1);
         h64 = XXH64_mergeRound(h64, v2);
         h64 = XXH64_mergeRound(h64, v3);
         h64 = XXH64_mergeRound(h64, v4);
     } else {
         h64  = state->v3 + PRIME64_5;
     }
 
     h64 += (U64) state->total_len;
 
     while (p+8<=bEnd) {
         U64 const k1 = XXH64_round(0, XXH_readLE64(p, endian));
         h64 ^= k1;
         h64  = XXH_rotl64(h64,27) * PRIME64_1 + PRIME64_4;
         p+=8;
     }
 
     if (p+4<=bEnd) {
         h64 ^= (U64)(XXH_readLE32(p, endian)) * PRIME64_1;
         h64  = XXH_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
         p+=4;
     }
 
     while (p> 33;
     h64 *= PRIME64_2;
     h64 ^= h64 >> 29;
     h64 *= PRIME64_3;
     h64 ^= h64 >> 32;
 
     return h64;
 }
 
 
 XXH_PUBLIC_API unsigned long long XXH64_digest (const XXH64_state_t* state_in)
 {
     XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN;
 
     if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT)
         return XXH64_digest_endian(state_in, XXH_littleEndian);
     else
         return XXH64_digest_endian(state_in, XXH_bigEndian);
 }
 
 
 /* **************************
 *  Canonical representation
 ****************************/
 
 /*! Default XXH result types are basic unsigned 32 and 64 bits.
 *   The canonical representation follows human-readable write convention, aka big-endian (large digits first).
 *   These functions allow transformation of hash result into and from its canonical format.
 *   This way, hash values can be written into a file or buffer, and remain comparable across different systems and programs.
 */
 
 XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
 {
     XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t));
     if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
     memcpy(dst, &hash, sizeof(*dst));
 }
 
 XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash)
 {
     XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
     if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
     memcpy(dst, &hash, sizeof(*dst));
 }
 
 XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
 {
     return XXH_readBE32(src);
 }
 
 XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src)
 {
     return XXH_readBE64(src);
 }
Index: head/sys/contrib/zstd/lib/common/zstd_internal.h
===================================================================
--- head/sys/contrib/zstd/lib/common/zstd_internal.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/common/zstd_internal.h	(revision 354777)
@@ -1,371 +1,350 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_CCOMMON_H_MODULE
 #define ZSTD_CCOMMON_H_MODULE
 
 /* this module contains definitions which must be identical
  * across compression, decompression and dictBuilder.
  * It also contains a few functions useful to at least 2 of them
  * and which benefit from being inlined */
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include "compiler.h"
 #include "mem.h"
 #include "debug.h"                 /* assert, DEBUGLOG, RAWLOG, g_debuglevel */
 #include "error_private.h"
 #define ZSTD_STATIC_LINKING_ONLY
 #include "zstd.h"
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #ifndef XXH_STATIC_LINKING_ONLY
 #  define XXH_STATIC_LINKING_ONLY  /* XXH64_state_t */
 #endif
 #include "xxhash.h"                /* XXH_reset, update, digest */
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /* ---- static assert (debug) --- */
 #define ZSTD_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)
 #define ZSTD_isError ERR_isError   /* for inlining */
 #define FSE_isError  ERR_isError
 #define HUF_isError  ERR_isError
 
 
 /*-*************************************
 *  shared macros
 ***************************************/
 #undef MIN
 #undef MAX
 #define MIN(a,b) ((a)<(b) ? (a) : (b))
 #define MAX(a,b) ((a)>(b) ? (a) : (b))
 
 /**
  * Return the specified error if the condition evaluates to true.
  *
- * In debug modes, prints additional information. In order to do that
- * (particularly, printing the conditional that failed), this can't just wrap
- * RETURN_ERROR().
+ * In debug modes, prints additional information.
+ * In order to do that (particularly, printing the conditional that failed),
+ * this can't just wrap RETURN_ERROR().
  */
 #define RETURN_ERROR_IF(cond, err, ...) \
   if (cond) { \
     RAWLOG(3, "%s:%d: ERROR!: check %s failed, returning %s", __FILE__, __LINE__, ZSTD_QUOTE(cond), ZSTD_QUOTE(ERROR(err))); \
     RAWLOG(3, ": " __VA_ARGS__); \
     RAWLOG(3, "\n"); \
     return ERROR(err); \
   }
 
 /**
  * Unconditionally return the specified error.
  *
  * In debug modes, prints additional information.
  */
 #define RETURN_ERROR(err, ...) \
   do { \
     RAWLOG(3, "%s:%d: ERROR!: unconditional check failed, returning %s", __FILE__, __LINE__, ZSTD_QUOTE(ERROR(err))); \
     RAWLOG(3, ": " __VA_ARGS__); \
     RAWLOG(3, "\n"); \
     return ERROR(err); \
   } while(0);
 
 /**
  * If the provided expression evaluates to an error code, returns that error code.
  *
  * In debug modes, prints additional information.
  */
 #define FORWARD_IF_ERROR(err, ...) \
   do { \
     size_t const err_code = (err); \
     if (ERR_isError(err_code)) { \
       RAWLOG(3, "%s:%d: ERROR!: forwarding error in %s: %s", __FILE__, __LINE__, ZSTD_QUOTE(err), ERR_getErrorName(err_code)); \
       RAWLOG(3, ": " __VA_ARGS__); \
       RAWLOG(3, "\n"); \
       return err_code; \
     } \
   } while(0);
 
 
 /*-*************************************
 *  Common constants
 ***************************************/
 #define ZSTD_OPT_NUM    (1<<12)
 
 #define ZSTD_REP_NUM      3                 /* number of repcodes */
 #define ZSTD_REP_MOVE     (ZSTD_REP_NUM-1)
 static const U32 repStartValue[ZSTD_REP_NUM] = { 1, 4, 8 };
 
 #define KB *(1 <<10)
 #define MB *(1 <<20)
 #define GB *(1U<<30)
 
 #define BIT7 128
 #define BIT6  64
 #define BIT5  32
 #define BIT4  16
 #define BIT1   2
 #define BIT0   1
 
 #define ZSTD_WINDOWLOG_ABSOLUTEMIN 10
 static const size_t ZSTD_fcs_fieldSize[4] = { 0, 2, 4, 8 };
 static const size_t ZSTD_did_fieldSize[4] = { 0, 1, 2, 4 };
 
 #define ZSTD_FRAMEIDSIZE 4   /* magic number size */
 
 #define ZSTD_BLOCKHEADERSIZE 3   /* C standard doesn't allow `static const` variable to be init using another `static const` variable */
 static const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
 typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e;
 
 #define MIN_SEQUENCES_SIZE 1 /* nbSeq==0 */
 #define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */ + MIN_SEQUENCES_SIZE /* nbSeq==0 */)   /* for a non-null block */
 
 #define HufLog 12
 typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingType_e;
 
 #define LONGNBSEQ 0x7F00
 
 #define MINMATCH 3
 
 #define Litbits  8
 #define MaxLit ((1<= 8 || (ovtype == ZSTD_no_overlap && diff < -8));
-    if (length < VECLEN || (ovtype == ZSTD_overlap_src_before_dst && diff < VECLEN)) {
-      do
-          COPY8(op, ip)
-      while (op < oend);
-    }
-    else {
-      if ((length & 8) == 0)
-        COPY8(op, ip);
-      do {
-        COPY16(op, ip);
-      }
-      while (op < oend);
-    }
-}
+    assert(diff >= 8 || (ovtype == ZSTD_no_overlap && diff <= -WILDCOPY_VECLEN));
 
-/*! ZSTD_wildcopy_16min() :
- *  same semantics as ZSTD_wilcopy() except guaranteed to be able to copy 16 bytes at the start */
-MEM_STATIC FORCE_INLINE_ATTR DONT_VECTORIZE
-void ZSTD_wildcopy_16min(void* dst, const void* src, ptrdiff_t length, ZSTD_overlap_e ovtype)
-{
-    ptrdiff_t diff = (BYTE*)dst - (const BYTE*)src;
-    const BYTE* ip = (const BYTE*)src;
-    BYTE* op = (BYTE*)dst;
-    BYTE* const oend = op + length;
-
-    assert(length >= 8);
-    assert(diff >= 8 || (ovtype == ZSTD_no_overlap && diff < -8));
-
-    if (ovtype == ZSTD_overlap_src_before_dst && diff < VECLEN) {
-      do
-          COPY8(op, ip)
-      while (op < oend);
-    }
-    else {
-      if ((length & 8) == 0)
-        COPY8(op, ip);
-      do {
+    if (ovtype == ZSTD_overlap_src_before_dst && diff < WILDCOPY_VECLEN) {
+        /* Handle short offset copies. */
+        do {
+            COPY8(op, ip)
+        } while (op < oend);
+    } else {
+        assert(diff >= WILDCOPY_VECLEN || diff <= -WILDCOPY_VECLEN);
+        /* Separate out the first two COPY16() calls because the copy length is
+         * almost certain to be short, so the branches have different
+         * probabilities.
+         * On gcc-9 unrolling once is +1.6%, twice is +2%, thrice is +1.8%.
+         * On clang-8 unrolling once is +1.4%, twice is +3.3%, thrice is +3%.
+         */
         COPY16(op, ip);
-      }
-      while (op < oend);
+        COPY16(op, ip);
+        if (op >= oend) return;
+        do {
+            COPY16(op, ip);
+            COPY16(op, ip);
+        }
+        while (op < oend);
     }
 }
 
-MEM_STATIC void ZSTD_wildcopy_e(void* dst, const void* src, void* dstEnd)   /* should be faster for decoding, but strangely, not verified on all platform */
-{
-    const BYTE* ip = (const BYTE*)src;
-    BYTE* op = (BYTE*)dst;
-    BYTE* const oend = (BYTE*)dstEnd;
-    do
-        COPY8(op, ip)
-    while (op < oend);
-}
 
-
 /*-*******************************************
 *  Private declarations
 *********************************************/
 typedef struct seqDef_s {
     U32 offset;
     U16 litLength;
     U16 matchLength;
 } seqDef;
 
 typedef struct {
     seqDef* sequencesStart;
     seqDef* sequences;
     BYTE* litStart;
     BYTE* lit;
     BYTE* llCode;
     BYTE* mlCode;
     BYTE* ofCode;
     size_t maxNbSeq;
     size_t maxNbLit;
     U32   longLengthID;   /* 0 == no longLength; 1 == Lit.longLength; 2 == Match.longLength; */
     U32   longLengthPos;
 } seqStore_t;
 
 /**
  * Contains the compressed frame size and an upper-bound for the decompressed frame size.
  * Note: before using `compressedSize`, check for errors using ZSTD_isError().
  *       similarly, before using `decompressedBound`, check for errors using:
  *          `decompressedBound != ZSTD_CONTENTSIZE_ERROR`
  */
 typedef struct {
     size_t compressedSize;
     unsigned long long decompressedBound;
 } ZSTD_frameSizeInfo;   /* decompress & legacy */
 
 const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx);   /* compress & dictBuilder */
 void ZSTD_seqToCodes(const seqStore_t* seqStorePtr);   /* compress, dictBuilder, decodeCorpus (shouldn't get its definition from here) */
 
 /* custom memory allocation functions */
 void* ZSTD_malloc(size_t size, ZSTD_customMem customMem);
 void* ZSTD_calloc(size_t size, ZSTD_customMem customMem);
 void ZSTD_free(void* ptr, ZSTD_customMem customMem);
 
 
 MEM_STATIC U32 ZSTD_highbit32(U32 val)   /* compress, dictBuilder, decodeCorpus */
 {
     assert(val != 0);
     {
 #   if defined(_MSC_VER)   /* Visual */
         unsigned long r=0;
         _BitScanReverse(&r, val);
         return (unsigned)r;
 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* GCC Intrinsic */
-        return 31 - __builtin_clz(val);
+        return __builtin_clz (val) ^ 31;
+#   elif defined(__ICCARM__)    /* IAR Intrinsic */
+        return 31 - __CLZ(val);
 #   else   /* Software version */
         static const U32 DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
         U32 v = val;
         v |= v >> 1;
         v |= v >> 2;
         v |= v >> 4;
         v |= v >> 8;
         v |= v >> 16;
         return DeBruijnClz[(v * 0x07C4ACDDU) >> 27];
 #   endif
     }
 }
 
 
 /* ZSTD_invalidateRepCodes() :
  * ensures next compression will not use repcodes from previous block.
  * Note : only works with regular variant;
  *        do not use with extDict variant ! */
 void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx);   /* zstdmt, adaptive_compression (shouldn't get this definition from here) */
 
 
 typedef struct {
     blockType_e blockType;
     U32 lastBlock;
     U32 origSize;
 } blockProperties_t;   /* declared here for decompress and fullbench */
 
 /*! ZSTD_getcBlockSize() :
  *  Provides the size of compressed block from block header `src` */
 /* Used by: decompress, fullbench (does not get its definition from here) */
 size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
                           blockProperties_t* bpPtr);
 
 /*! ZSTD_decodeSeqHeaders() :
  *  decode sequence header from src */
 /* Used by: decompress, fullbench (does not get its definition from here) */
 size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
                        const void* src, size_t srcSize);
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif   /* ZSTD_CCOMMON_H_MODULE */
Index: head/sys/contrib/zstd/lib/compress/zstd_compress.c
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_compress.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_compress.c	(revision 354777)
@@ -1,3904 +1,4103 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include          /* INT_MAX */
 #include          /* memset */
 #include "cpu.h"
 #include "mem.h"
 #include "hist.h"           /* HIST_countFast_wksp */
 #define FSE_STATIC_LINKING_ONLY   /* FSE_encodeSymbol */
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "zstd_compress_internal.h"
 #include "zstd_compress_sequences.h"
 #include "zstd_compress_literals.h"
 #include "zstd_fast.h"
 #include "zstd_double_fast.h"
 #include "zstd_lazy.h"
 #include "zstd_opt.h"
 #include "zstd_ldm.h"
 
 
 /*-*************************************
 *  Helper functions
 ***************************************/
 size_t ZSTD_compressBound(size_t srcSize) {
     return ZSTD_COMPRESSBOUND(srcSize);
 }
 
 
 /*-*************************************
 *  Context memory management
 ***************************************/
 struct ZSTD_CDict_s {
-    void* dictBuffer;
     const void* dictContent;
     size_t dictContentSize;
-    void* workspace;
-    size_t workspaceSize;
+    U32* entropyWorkspace; /* entropy workspace of HUF_WORKSPACE_SIZE bytes */
+    ZSTD_cwksp workspace;
     ZSTD_matchState_t matchState;
     ZSTD_compressedBlockState_t cBlockState;
     ZSTD_customMem customMem;
     U32 dictID;
+    int compressionLevel; /* 0 indicates that advanced API was used to select CDict params */
 };  /* typedef'd to ZSTD_CDict within "zstd.h" */
 
 ZSTD_CCtx* ZSTD_createCCtx(void)
 {
     return ZSTD_createCCtx_advanced(ZSTD_defaultCMem);
 }
 
 static void ZSTD_initCCtx(ZSTD_CCtx* cctx, ZSTD_customMem memManager)
 {
     assert(cctx != NULL);
     memset(cctx, 0, sizeof(*cctx));
     cctx->customMem = memManager;
     cctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
     {   size_t const err = ZSTD_CCtx_reset(cctx, ZSTD_reset_parameters);
         assert(!ZSTD_isError(err));
         (void)err;
     }
 }
 
 ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem)
 {
     ZSTD_STATIC_ASSERT(zcss_init==0);
     ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN==(0ULL - 1));
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
     {   ZSTD_CCtx* const cctx = (ZSTD_CCtx*)ZSTD_malloc(sizeof(ZSTD_CCtx), customMem);
         if (!cctx) return NULL;
         ZSTD_initCCtx(cctx, customMem);
         return cctx;
     }
 }
 
 ZSTD_CCtx* ZSTD_initStaticCCtx(void *workspace, size_t workspaceSize)
 {
-    ZSTD_CCtx* const cctx = (ZSTD_CCtx*) workspace;
+    ZSTD_cwksp ws;
+    ZSTD_CCtx* cctx;
     if (workspaceSize <= sizeof(ZSTD_CCtx)) return NULL;  /* minimum size */
     if ((size_t)workspace & 7) return NULL;  /* must be 8-aligned */
-    memset(workspace, 0, workspaceSize);   /* may be a bit generous, could memset be smaller ? */
+    ZSTD_cwksp_init(&ws, workspace, workspaceSize);
+
+    cctx = (ZSTD_CCtx*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CCtx));
+    if (cctx == NULL) {
+        return NULL;
+    }
+    memset(cctx, 0, sizeof(ZSTD_CCtx));
+    ZSTD_cwksp_move(&cctx->workspace, &ws);
     cctx->staticSize = workspaceSize;
-    cctx->workSpace = (void*)(cctx+1);
-    cctx->workSpaceSize = workspaceSize - sizeof(ZSTD_CCtx);
 
     /* statically sized space. entropyWorkspace never moves (but prev/next block swap places) */
-    if (cctx->workSpaceSize < HUF_WORKSPACE_SIZE + 2 * sizeof(ZSTD_compressedBlockState_t)) return NULL;
-    assert(((size_t)cctx->workSpace & (sizeof(void*)-1)) == 0);   /* ensure correct alignment */
-    cctx->blockState.prevCBlock = (ZSTD_compressedBlockState_t*)cctx->workSpace;
-    cctx->blockState.nextCBlock = cctx->blockState.prevCBlock + 1;
-    {
-        void* const ptr = cctx->blockState.nextCBlock + 1;
-        cctx->entropyWorkspace = (U32*)ptr;
-    }
+    if (!ZSTD_cwksp_check_available(&cctx->workspace, HUF_WORKSPACE_SIZE + 2 * sizeof(ZSTD_compressedBlockState_t))) return NULL;
+    cctx->blockState.prevCBlock = (ZSTD_compressedBlockState_t*)ZSTD_cwksp_reserve_object(&cctx->workspace, sizeof(ZSTD_compressedBlockState_t));
+    cctx->blockState.nextCBlock = (ZSTD_compressedBlockState_t*)ZSTD_cwksp_reserve_object(&cctx->workspace, sizeof(ZSTD_compressedBlockState_t));
+    cctx->entropyWorkspace = (U32*)ZSTD_cwksp_reserve_object(
+        &cctx->workspace, HUF_WORKSPACE_SIZE);
     cctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
     return cctx;
 }
 
 /**
  * Clears and frees all of the dictionaries in the CCtx.
  */
 static void ZSTD_clearAllDicts(ZSTD_CCtx* cctx)
 {
     ZSTD_free(cctx->localDict.dictBuffer, cctx->customMem);
     ZSTD_freeCDict(cctx->localDict.cdict);
     memset(&cctx->localDict, 0, sizeof(cctx->localDict));
     memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));
     cctx->cdict = NULL;
 }
 
 static size_t ZSTD_sizeof_localDict(ZSTD_localDict dict)
 {
     size_t const bufferSize = dict.dictBuffer != NULL ? dict.dictSize : 0;
     size_t const cdictSize = ZSTD_sizeof_CDict(dict.cdict);
     return bufferSize + cdictSize;
 }
 
 static void ZSTD_freeCCtxContent(ZSTD_CCtx* cctx)
 {
     assert(cctx != NULL);
     assert(cctx->staticSize == 0);
-    ZSTD_free(cctx->workSpace, cctx->customMem); cctx->workSpace = NULL;
     ZSTD_clearAllDicts(cctx);
 #ifdef ZSTD_MULTITHREAD
     ZSTDMT_freeCCtx(cctx->mtctx); cctx->mtctx = NULL;
 #endif
+    ZSTD_cwksp_free(&cctx->workspace, cctx->customMem);
 }
 
 size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx)
 {
     if (cctx==NULL) return 0;   /* support free on NULL */
     RETURN_ERROR_IF(cctx->staticSize, memory_allocation,
                     "not compatible with static CCtx");
-    ZSTD_freeCCtxContent(cctx);
-    ZSTD_free(cctx, cctx->customMem);
+    {
+        int cctxInWorkspace = ZSTD_cwksp_owns_buffer(&cctx->workspace, cctx);
+        ZSTD_freeCCtxContent(cctx);
+        if (!cctxInWorkspace) {
+            ZSTD_free(cctx, cctx->customMem);
+        }
+    }
     return 0;
 }
 
 
 static size_t ZSTD_sizeof_mtctx(const ZSTD_CCtx* cctx)
 {
 #ifdef ZSTD_MULTITHREAD
     return ZSTDMT_sizeof_CCtx(cctx->mtctx);
 #else
     (void)cctx;
     return 0;
 #endif
 }
 
 
 size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx)
 {
     if (cctx==NULL) return 0;   /* support sizeof on NULL */
-    return sizeof(*cctx) + cctx->workSpaceSize
+    /* cctx may be in the workspace */
+    return (cctx->workspace.workspace == cctx ? 0 : sizeof(*cctx))
+           + ZSTD_cwksp_sizeof(&cctx->workspace)
            + ZSTD_sizeof_localDict(cctx->localDict)
            + ZSTD_sizeof_mtctx(cctx);
 }
 
 size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs)
 {
     return ZSTD_sizeof_CCtx(zcs);  /* same object */
 }
 
 /* private API call, for dictBuilder only */
 const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx) { return &(ctx->seqStore); }
 
 static ZSTD_CCtx_params ZSTD_makeCCtxParamsFromCParams(
         ZSTD_compressionParameters cParams)
 {
     ZSTD_CCtx_params cctxParams;
     memset(&cctxParams, 0, sizeof(cctxParams));
     cctxParams.cParams = cParams;
     cctxParams.compressionLevel = ZSTD_CLEVEL_DEFAULT;  /* should not matter, as all cParams are presumed properly defined */
     assert(!ZSTD_checkCParams(cParams));
     cctxParams.fParams.contentSizeFlag = 1;
     return cctxParams;
 }
 
 static ZSTD_CCtx_params* ZSTD_createCCtxParams_advanced(
         ZSTD_customMem customMem)
 {
     ZSTD_CCtx_params* params;
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
     params = (ZSTD_CCtx_params*)ZSTD_calloc(
             sizeof(ZSTD_CCtx_params), customMem);
     if (!params) { return NULL; }
     params->customMem = customMem;
     params->compressionLevel = ZSTD_CLEVEL_DEFAULT;
     params->fParams.contentSizeFlag = 1;
     return params;
 }
 
 ZSTD_CCtx_params* ZSTD_createCCtxParams(void)
 {
     return ZSTD_createCCtxParams_advanced(ZSTD_defaultCMem);
 }
 
 size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params)
 {
     if (params == NULL) { return 0; }
     ZSTD_free(params, params->customMem);
     return 0;
 }
 
 size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params)
 {
     return ZSTD_CCtxParams_init(params, ZSTD_CLEVEL_DEFAULT);
 }
 
 size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel) {
     RETURN_ERROR_IF(!cctxParams, GENERIC);
     memset(cctxParams, 0, sizeof(*cctxParams));
     cctxParams->compressionLevel = compressionLevel;
     cctxParams->fParams.contentSizeFlag = 1;
     return 0;
 }
 
 size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params)
 {
     RETURN_ERROR_IF(!cctxParams, GENERIC);
     FORWARD_IF_ERROR( ZSTD_checkCParams(params.cParams) );
     memset(cctxParams, 0, sizeof(*cctxParams));
+    assert(!ZSTD_checkCParams(params.cParams));
     cctxParams->cParams = params.cParams;
     cctxParams->fParams = params.fParams;
     cctxParams->compressionLevel = ZSTD_CLEVEL_DEFAULT;   /* should not matter, as all cParams are presumed properly defined */
-    assert(!ZSTD_checkCParams(params.cParams));
     return 0;
 }
 
 /* ZSTD_assignParamsToCCtxParams() :
  * params is presumed valid at this stage */
 static ZSTD_CCtx_params ZSTD_assignParamsToCCtxParams(
-        ZSTD_CCtx_params cctxParams, ZSTD_parameters params)
+        const ZSTD_CCtx_params* cctxParams, ZSTD_parameters params)
 {
-    ZSTD_CCtx_params ret = cctxParams;
+    ZSTD_CCtx_params ret = *cctxParams;
+    assert(!ZSTD_checkCParams(params.cParams));
     ret.cParams = params.cParams;
     ret.fParams = params.fParams;
     ret.compressionLevel = ZSTD_CLEVEL_DEFAULT;   /* should not matter, as all cParams are presumed properly defined */
-    assert(!ZSTD_checkCParams(params.cParams));
     return ret;
 }
 
 ZSTD_bounds ZSTD_cParam_getBounds(ZSTD_cParameter param)
 {
     ZSTD_bounds bounds = { 0, 0, 0 };
 
     switch(param)
     {
     case ZSTD_c_compressionLevel:
         bounds.lowerBound = ZSTD_minCLevel();
         bounds.upperBound = ZSTD_maxCLevel();
         return bounds;
 
     case ZSTD_c_windowLog:
         bounds.lowerBound = ZSTD_WINDOWLOG_MIN;
         bounds.upperBound = ZSTD_WINDOWLOG_MAX;
         return bounds;
 
     case ZSTD_c_hashLog:
         bounds.lowerBound = ZSTD_HASHLOG_MIN;
         bounds.upperBound = ZSTD_HASHLOG_MAX;
         return bounds;
 
     case ZSTD_c_chainLog:
         bounds.lowerBound = ZSTD_CHAINLOG_MIN;
         bounds.upperBound = ZSTD_CHAINLOG_MAX;
         return bounds;
 
     case ZSTD_c_searchLog:
         bounds.lowerBound = ZSTD_SEARCHLOG_MIN;
         bounds.upperBound = ZSTD_SEARCHLOG_MAX;
         return bounds;
 
     case ZSTD_c_minMatch:
         bounds.lowerBound = ZSTD_MINMATCH_MIN;
         bounds.upperBound = ZSTD_MINMATCH_MAX;
         return bounds;
 
     case ZSTD_c_targetLength:
         bounds.lowerBound = ZSTD_TARGETLENGTH_MIN;
         bounds.upperBound = ZSTD_TARGETLENGTH_MAX;
         return bounds;
 
     case ZSTD_c_strategy:
         bounds.lowerBound = ZSTD_STRATEGY_MIN;
         bounds.upperBound = ZSTD_STRATEGY_MAX;
         return bounds;
 
     case ZSTD_c_contentSizeFlag:
         bounds.lowerBound = 0;
         bounds.upperBound = 1;
         return bounds;
 
     case ZSTD_c_checksumFlag:
         bounds.lowerBound = 0;
         bounds.upperBound = 1;
         return bounds;
 
     case ZSTD_c_dictIDFlag:
         bounds.lowerBound = 0;
         bounds.upperBound = 1;
         return bounds;
 
     case ZSTD_c_nbWorkers:
         bounds.lowerBound = 0;
 #ifdef ZSTD_MULTITHREAD
         bounds.upperBound = ZSTDMT_NBWORKERS_MAX;
 #else
         bounds.upperBound = 0;
 #endif
         return bounds;
 
     case ZSTD_c_jobSize:
         bounds.lowerBound = 0;
 #ifdef ZSTD_MULTITHREAD
         bounds.upperBound = ZSTDMT_JOBSIZE_MAX;
 #else
         bounds.upperBound = 0;
 #endif
         return bounds;
 
     case ZSTD_c_overlapLog:
         bounds.lowerBound = ZSTD_OVERLAPLOG_MIN;
         bounds.upperBound = ZSTD_OVERLAPLOG_MAX;
         return bounds;
 
     case ZSTD_c_enableLongDistanceMatching:
         bounds.lowerBound = 0;
         bounds.upperBound = 1;
         return bounds;
 
     case ZSTD_c_ldmHashLog:
         bounds.lowerBound = ZSTD_LDM_HASHLOG_MIN;
         bounds.upperBound = ZSTD_LDM_HASHLOG_MAX;
         return bounds;
 
     case ZSTD_c_ldmMinMatch:
         bounds.lowerBound = ZSTD_LDM_MINMATCH_MIN;
         bounds.upperBound = ZSTD_LDM_MINMATCH_MAX;
         return bounds;
 
     case ZSTD_c_ldmBucketSizeLog:
         bounds.lowerBound = ZSTD_LDM_BUCKETSIZELOG_MIN;
         bounds.upperBound = ZSTD_LDM_BUCKETSIZELOG_MAX;
         return bounds;
 
     case ZSTD_c_ldmHashRateLog:
         bounds.lowerBound = ZSTD_LDM_HASHRATELOG_MIN;
         bounds.upperBound = ZSTD_LDM_HASHRATELOG_MAX;
         return bounds;
 
     /* experimental parameters */
     case ZSTD_c_rsyncable:
         bounds.lowerBound = 0;
         bounds.upperBound = 1;
         return bounds;
 
     case ZSTD_c_forceMaxWindow :
         bounds.lowerBound = 0;
         bounds.upperBound = 1;
         return bounds;
 
     case ZSTD_c_format:
         ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless);
         bounds.lowerBound = ZSTD_f_zstd1;
         bounds.upperBound = ZSTD_f_zstd1_magicless;   /* note : how to ensure at compile time that this is the highest value enum ? */
         return bounds;
 
     case ZSTD_c_forceAttachDict:
         ZSTD_STATIC_ASSERT(ZSTD_dictDefaultAttach < ZSTD_dictForceCopy);
         bounds.lowerBound = ZSTD_dictDefaultAttach;
-        bounds.upperBound = ZSTD_dictForceCopy;       /* note : how to ensure at compile time that this is the highest value enum ? */
+        bounds.upperBound = ZSTD_dictForceLoad;       /* note : how to ensure at compile time that this is the highest value enum ? */
         return bounds;
 
     case ZSTD_c_literalCompressionMode:
         ZSTD_STATIC_ASSERT(ZSTD_lcm_auto < ZSTD_lcm_huffman && ZSTD_lcm_huffman < ZSTD_lcm_uncompressed);
         bounds.lowerBound = ZSTD_lcm_auto;
         bounds.upperBound = ZSTD_lcm_uncompressed;
         return bounds;
 
     case ZSTD_c_targetCBlockSize:
         bounds.lowerBound = ZSTD_TARGETCBLOCKSIZE_MIN;
         bounds.upperBound = ZSTD_TARGETCBLOCKSIZE_MAX;
         return bounds;
 
+    case ZSTD_c_srcSizeHint:
+        bounds.lowerBound = ZSTD_SRCSIZEHINT_MIN;
+        bounds.upperBound = ZSTD_SRCSIZEHINT_MAX;
+        return bounds;
+
     default:
         {   ZSTD_bounds const boundError = { ERROR(parameter_unsupported), 0, 0 };
             return boundError;
         }
     }
 }
 
 /* ZSTD_cParam_clampBounds:
  * Clamps the value into the bounded range.
  */
 static size_t ZSTD_cParam_clampBounds(ZSTD_cParameter cParam, int* value)
 {
     ZSTD_bounds const bounds = ZSTD_cParam_getBounds(cParam);
     if (ZSTD_isError(bounds.error)) return bounds.error;
     if (*value < bounds.lowerBound) *value = bounds.lowerBound;
     if (*value > bounds.upperBound) *value = bounds.upperBound;
     return 0;
 }
 
 #define BOUNDCHECK(cParam, val) { \
     RETURN_ERROR_IF(!ZSTD_cParam_withinBounds(cParam,val), \
                     parameter_outOfBound); \
 }
 
 
 static int ZSTD_isUpdateAuthorized(ZSTD_cParameter param)
 {
     switch(param)
     {
     case ZSTD_c_compressionLevel:
     case ZSTD_c_hashLog:
     case ZSTD_c_chainLog:
     case ZSTD_c_searchLog:
     case ZSTD_c_minMatch:
     case ZSTD_c_targetLength:
     case ZSTD_c_strategy:
         return 1;
 
     case ZSTD_c_format:
     case ZSTD_c_windowLog:
     case ZSTD_c_contentSizeFlag:
     case ZSTD_c_checksumFlag:
     case ZSTD_c_dictIDFlag:
     case ZSTD_c_forceMaxWindow :
     case ZSTD_c_nbWorkers:
     case ZSTD_c_jobSize:
     case ZSTD_c_overlapLog:
     case ZSTD_c_rsyncable:
     case ZSTD_c_enableLongDistanceMatching:
     case ZSTD_c_ldmHashLog:
     case ZSTD_c_ldmMinMatch:
     case ZSTD_c_ldmBucketSizeLog:
     case ZSTD_c_ldmHashRateLog:
     case ZSTD_c_forceAttachDict:
     case ZSTD_c_literalCompressionMode:
     case ZSTD_c_targetCBlockSize:
+    case ZSTD_c_srcSizeHint:
     default:
         return 0;
     }
 }
 
 size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int value)
 {
     DEBUGLOG(4, "ZSTD_CCtx_setParameter (%i, %i)", (int)param, value);
     if (cctx->streamStage != zcss_init) {
         if (ZSTD_isUpdateAuthorized(param)) {
             cctx->cParamsChanged = 1;
         } else {
             RETURN_ERROR(stage_wrong);
     }   }
 
     switch(param)
     {
     case ZSTD_c_nbWorkers:
         RETURN_ERROR_IF((value!=0) && cctx->staticSize, parameter_unsupported,
                         "MT not compatible with static alloc");
         break;
 
     case ZSTD_c_compressionLevel:
     case ZSTD_c_windowLog:
     case ZSTD_c_hashLog:
     case ZSTD_c_chainLog:
     case ZSTD_c_searchLog:
     case ZSTD_c_minMatch:
     case ZSTD_c_targetLength:
     case ZSTD_c_strategy:
     case ZSTD_c_ldmHashRateLog:
     case ZSTD_c_format:
     case ZSTD_c_contentSizeFlag:
     case ZSTD_c_checksumFlag:
     case ZSTD_c_dictIDFlag:
     case ZSTD_c_forceMaxWindow:
     case ZSTD_c_forceAttachDict:
     case ZSTD_c_literalCompressionMode:
     case ZSTD_c_jobSize:
     case ZSTD_c_overlapLog:
     case ZSTD_c_rsyncable:
     case ZSTD_c_enableLongDistanceMatching:
     case ZSTD_c_ldmHashLog:
     case ZSTD_c_ldmMinMatch:
     case ZSTD_c_ldmBucketSizeLog:
     case ZSTD_c_targetCBlockSize:
+    case ZSTD_c_srcSizeHint:
         break;
 
     default: RETURN_ERROR(parameter_unsupported);
     }
     return ZSTD_CCtxParams_setParameter(&cctx->requestedParams, param, value);
 }
 
 size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* CCtxParams,
                                     ZSTD_cParameter param, int value)
 {
     DEBUGLOG(4, "ZSTD_CCtxParams_setParameter (%i, %i)", (int)param, value);
     switch(param)
     {
     case ZSTD_c_format :
         BOUNDCHECK(ZSTD_c_format, value);
         CCtxParams->format = (ZSTD_format_e)value;
         return (size_t)CCtxParams->format;
 
     case ZSTD_c_compressionLevel : {
         FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(param, &value));
         if (value) {  /* 0 : does not change current level */
             CCtxParams->compressionLevel = value;
         }
-        if (CCtxParams->compressionLevel >= 0) return CCtxParams->compressionLevel;
+        if (CCtxParams->compressionLevel >= 0) return (size_t)CCtxParams->compressionLevel;
         return 0;  /* return type (size_t) cannot represent negative values */
     }
 
     case ZSTD_c_windowLog :
         if (value!=0)   /* 0 => use default */
             BOUNDCHECK(ZSTD_c_windowLog, value);
-        CCtxParams->cParams.windowLog = value;
+        CCtxParams->cParams.windowLog = (U32)value;
         return CCtxParams->cParams.windowLog;
 
     case ZSTD_c_hashLog :
         if (value!=0)   /* 0 => use default */
             BOUNDCHECK(ZSTD_c_hashLog, value);
-        CCtxParams->cParams.hashLog = value;
+        CCtxParams->cParams.hashLog = (U32)value;
         return CCtxParams->cParams.hashLog;
 
     case ZSTD_c_chainLog :
         if (value!=0)   /* 0 => use default */
             BOUNDCHECK(ZSTD_c_chainLog, value);
-        CCtxParams->cParams.chainLog = value;
+        CCtxParams->cParams.chainLog = (U32)value;
         return CCtxParams->cParams.chainLog;
 
     case ZSTD_c_searchLog :
         if (value!=0)   /* 0 => use default */
             BOUNDCHECK(ZSTD_c_searchLog, value);
-        CCtxParams->cParams.searchLog = value;
-        return value;
+        CCtxParams->cParams.searchLog = (U32)value;
+        return (size_t)value;
 
     case ZSTD_c_minMatch :
         if (value!=0)   /* 0 => use default */
             BOUNDCHECK(ZSTD_c_minMatch, value);
         CCtxParams->cParams.minMatch = value;
         return CCtxParams->cParams.minMatch;
 
     case ZSTD_c_targetLength :
         BOUNDCHECK(ZSTD_c_targetLength, value);
         CCtxParams->cParams.targetLength = value;
         return CCtxParams->cParams.targetLength;
 
     case ZSTD_c_strategy :
         if (value!=0)   /* 0 => use default */
             BOUNDCHECK(ZSTD_c_strategy, value);
         CCtxParams->cParams.strategy = (ZSTD_strategy)value;
         return (size_t)CCtxParams->cParams.strategy;
 
     case ZSTD_c_contentSizeFlag :
         /* Content size written in frame header _when known_ (default:1) */
         DEBUGLOG(4, "set content size flag = %u", (value!=0));
         CCtxParams->fParams.contentSizeFlag = value != 0;
         return CCtxParams->fParams.contentSizeFlag;
 
     case ZSTD_c_checksumFlag :
         /* A 32-bits content checksum will be calculated and written at end of frame (default:0) */
         CCtxParams->fParams.checksumFlag = value != 0;
         return CCtxParams->fParams.checksumFlag;
 
     case ZSTD_c_dictIDFlag : /* When applicable, dictionary's dictID is provided in frame header (default:1) */
         DEBUGLOG(4, "set dictIDFlag = %u", (value!=0));
         CCtxParams->fParams.noDictIDFlag = !value;
         return !CCtxParams->fParams.noDictIDFlag;
 
     case ZSTD_c_forceMaxWindow :
         CCtxParams->forceWindow = (value != 0);
         return CCtxParams->forceWindow;
 
     case ZSTD_c_forceAttachDict : {
         const ZSTD_dictAttachPref_e pref = (ZSTD_dictAttachPref_e)value;
         BOUNDCHECK(ZSTD_c_forceAttachDict, pref);
         CCtxParams->attachDictPref = pref;
         return CCtxParams->attachDictPref;
     }
 
     case ZSTD_c_literalCompressionMode : {
         const ZSTD_literalCompressionMode_e lcm = (ZSTD_literalCompressionMode_e)value;
         BOUNDCHECK(ZSTD_c_literalCompressionMode, lcm);
         CCtxParams->literalCompressionMode = lcm;
         return CCtxParams->literalCompressionMode;
     }
 
     case ZSTD_c_nbWorkers :
 #ifndef ZSTD_MULTITHREAD
         RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
         return 0;
 #else
         FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(param, &value));
         CCtxParams->nbWorkers = value;
         return CCtxParams->nbWorkers;
 #endif
 
     case ZSTD_c_jobSize :
 #ifndef ZSTD_MULTITHREAD
         RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
         return 0;
 #else
         /* Adjust to the minimum non-default value. */
         if (value != 0 && value < ZSTDMT_JOBSIZE_MIN)
             value = ZSTDMT_JOBSIZE_MIN;
         FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(param, &value));
         assert(value >= 0);
         CCtxParams->jobSize = value;
         return CCtxParams->jobSize;
 #endif
 
     case ZSTD_c_overlapLog :
 #ifndef ZSTD_MULTITHREAD
         RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
         return 0;
 #else
         FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(ZSTD_c_overlapLog, &value));
         CCtxParams->overlapLog = value;
         return CCtxParams->overlapLog;
 #endif
 
     case ZSTD_c_rsyncable :
 #ifndef ZSTD_MULTITHREAD
         RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
         return 0;
 #else
         FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(ZSTD_c_overlapLog, &value));
         CCtxParams->rsyncable = value;
         return CCtxParams->rsyncable;
 #endif
 
     case ZSTD_c_enableLongDistanceMatching :
         CCtxParams->ldmParams.enableLdm = (value!=0);
         return CCtxParams->ldmParams.enableLdm;
 
     case ZSTD_c_ldmHashLog :
         if (value!=0)   /* 0 ==> auto */
             BOUNDCHECK(ZSTD_c_ldmHashLog, value);
         CCtxParams->ldmParams.hashLog = value;
         return CCtxParams->ldmParams.hashLog;
 
     case ZSTD_c_ldmMinMatch :
         if (value!=0)   /* 0 ==> default */
             BOUNDCHECK(ZSTD_c_ldmMinMatch, value);
         CCtxParams->ldmParams.minMatchLength = value;
         return CCtxParams->ldmParams.minMatchLength;
 
     case ZSTD_c_ldmBucketSizeLog :
         if (value!=0)   /* 0 ==> default */
             BOUNDCHECK(ZSTD_c_ldmBucketSizeLog, value);
         CCtxParams->ldmParams.bucketSizeLog = value;
         return CCtxParams->ldmParams.bucketSizeLog;
 
     case ZSTD_c_ldmHashRateLog :
         RETURN_ERROR_IF(value > ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN,
                         parameter_outOfBound);
         CCtxParams->ldmParams.hashRateLog = value;
         return CCtxParams->ldmParams.hashRateLog;
 
     case ZSTD_c_targetCBlockSize :
         if (value!=0)   /* 0 ==> default */
             BOUNDCHECK(ZSTD_c_targetCBlockSize, value);
         CCtxParams->targetCBlockSize = value;
         return CCtxParams->targetCBlockSize;
 
+    case ZSTD_c_srcSizeHint :
+        if (value!=0)    /* 0 ==> default */
+            BOUNDCHECK(ZSTD_c_srcSizeHint, value);
+        CCtxParams->srcSizeHint = value;
+        return CCtxParams->srcSizeHint;
+
     default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
     }
 }
 
 size_t ZSTD_CCtx_getParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int* value)
 {
     return ZSTD_CCtxParams_getParameter(&cctx->requestedParams, param, value);
 }
 
 size_t ZSTD_CCtxParams_getParameter(
         ZSTD_CCtx_params* CCtxParams, ZSTD_cParameter param, int* value)
 {
     switch(param)
     {
     case ZSTD_c_format :
         *value = CCtxParams->format;
         break;
     case ZSTD_c_compressionLevel :
         *value = CCtxParams->compressionLevel;
         break;
     case ZSTD_c_windowLog :
         *value = (int)CCtxParams->cParams.windowLog;
         break;
     case ZSTD_c_hashLog :
         *value = (int)CCtxParams->cParams.hashLog;
         break;
     case ZSTD_c_chainLog :
         *value = (int)CCtxParams->cParams.chainLog;
         break;
     case ZSTD_c_searchLog :
         *value = CCtxParams->cParams.searchLog;
         break;
     case ZSTD_c_minMatch :
         *value = CCtxParams->cParams.minMatch;
         break;
     case ZSTD_c_targetLength :
         *value = CCtxParams->cParams.targetLength;
         break;
     case ZSTD_c_strategy :
         *value = (unsigned)CCtxParams->cParams.strategy;
         break;
     case ZSTD_c_contentSizeFlag :
         *value = CCtxParams->fParams.contentSizeFlag;
         break;
     case ZSTD_c_checksumFlag :
         *value = CCtxParams->fParams.checksumFlag;
         break;
     case ZSTD_c_dictIDFlag :
         *value = !CCtxParams->fParams.noDictIDFlag;
         break;
     case ZSTD_c_forceMaxWindow :
         *value = CCtxParams->forceWindow;
         break;
     case ZSTD_c_forceAttachDict :
         *value = CCtxParams->attachDictPref;
         break;
     case ZSTD_c_literalCompressionMode :
         *value = CCtxParams->literalCompressionMode;
         break;
     case ZSTD_c_nbWorkers :
 #ifndef ZSTD_MULTITHREAD
         assert(CCtxParams->nbWorkers == 0);
 #endif
         *value = CCtxParams->nbWorkers;
         break;
     case ZSTD_c_jobSize :
 #ifndef ZSTD_MULTITHREAD
         RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
 #else
         assert(CCtxParams->jobSize <= INT_MAX);
         *value = (int)CCtxParams->jobSize;
         break;
 #endif
     case ZSTD_c_overlapLog :
 #ifndef ZSTD_MULTITHREAD
         RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
 #else
         *value = CCtxParams->overlapLog;
         break;
 #endif
     case ZSTD_c_rsyncable :
 #ifndef ZSTD_MULTITHREAD
         RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
 #else
         *value = CCtxParams->rsyncable;
         break;
 #endif
     case ZSTD_c_enableLongDistanceMatching :
         *value = CCtxParams->ldmParams.enableLdm;
         break;
     case ZSTD_c_ldmHashLog :
         *value = CCtxParams->ldmParams.hashLog;
         break;
     case ZSTD_c_ldmMinMatch :
         *value = CCtxParams->ldmParams.minMatchLength;
         break;
     case ZSTD_c_ldmBucketSizeLog :
         *value = CCtxParams->ldmParams.bucketSizeLog;
         break;
     case ZSTD_c_ldmHashRateLog :
         *value = CCtxParams->ldmParams.hashRateLog;
         break;
     case ZSTD_c_targetCBlockSize :
         *value = (int)CCtxParams->targetCBlockSize;
         break;
+    case ZSTD_c_srcSizeHint :
+        *value = (int)CCtxParams->srcSizeHint;
+        break;
     default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
     }
     return 0;
 }
 
 /** ZSTD_CCtx_setParametersUsingCCtxParams() :
  *  just applies `params` into `cctx`
  *  no action is performed, parameters are merely stored.
  *  If ZSTDMT is enabled, parameters are pushed to cctx->mtctx.
  *    This is possible even if a compression is ongoing.
  *    In which case, new parameters will be applied on the fly, starting with next compression job.
  */
 size_t ZSTD_CCtx_setParametersUsingCCtxParams(
         ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params)
 {
     DEBUGLOG(4, "ZSTD_CCtx_setParametersUsingCCtxParams");
     RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
     RETURN_ERROR_IF(cctx->cdict, stage_wrong);
 
     cctx->requestedParams = *params;
     return 0;
 }
 
 ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_CCtx_setPledgedSrcSize to %u bytes", (U32)pledgedSrcSize);
     RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
     cctx->pledgedSrcSizePlusOne = pledgedSrcSize+1;
     return 0;
 }
 
 /**
  * Initializes the local dict using the requested parameters.
  * NOTE: This does not use the pledged src size, because it may be used for more
  * than one compression.
  */
 static size_t ZSTD_initLocalDict(ZSTD_CCtx* cctx)
 {
     ZSTD_localDict* const dl = &cctx->localDict;
     ZSTD_compressionParameters const cParams = ZSTD_getCParamsFromCCtxParams(
             &cctx->requestedParams, 0, dl->dictSize);
     if (dl->dict == NULL) {
         /* No local dictionary. */
         assert(dl->dictBuffer == NULL);
         assert(dl->cdict == NULL);
         assert(dl->dictSize == 0);
         return 0;
     }
     if (dl->cdict != NULL) {
         assert(cctx->cdict == dl->cdict);
         /* Local dictionary already initialized. */
         return 0;
     }
     assert(dl->dictSize > 0);
     assert(cctx->cdict == NULL);
     assert(cctx->prefixDict.dict == NULL);
 
     dl->cdict = ZSTD_createCDict_advanced(
             dl->dict,
             dl->dictSize,
             ZSTD_dlm_byRef,
             dl->dictContentType,
             cParams,
             cctx->customMem);
     RETURN_ERROR_IF(!dl->cdict, memory_allocation);
     cctx->cdict = dl->cdict;
     return 0;
 }
 
 size_t ZSTD_CCtx_loadDictionary_advanced(
         ZSTD_CCtx* cctx, const void* dict, size_t dictSize,
         ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType)
 {
     RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
     RETURN_ERROR_IF(cctx->staticSize, memory_allocation,
                     "no malloc for static CCtx");
     DEBUGLOG(4, "ZSTD_CCtx_loadDictionary_advanced (size: %u)", (U32)dictSize);
     ZSTD_clearAllDicts(cctx);  /* in case one already exists */
     if (dict == NULL || dictSize == 0)  /* no dictionary mode */
         return 0;
     if (dictLoadMethod == ZSTD_dlm_byRef) {
         cctx->localDict.dict = dict;
     } else {
         void* dictBuffer = ZSTD_malloc(dictSize, cctx->customMem);
         RETURN_ERROR_IF(!dictBuffer, memory_allocation);
         memcpy(dictBuffer, dict, dictSize);
         cctx->localDict.dictBuffer = dictBuffer;
         cctx->localDict.dict = dictBuffer;
     }
     cctx->localDict.dictSize = dictSize;
     cctx->localDict.dictContentType = dictContentType;
     return 0;
 }
 
 ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary_byReference(
       ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
 {
     return ZSTD_CCtx_loadDictionary_advanced(
             cctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
 }
 
 ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
 {
     return ZSTD_CCtx_loadDictionary_advanced(
             cctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
 }
 
 
 size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
 {
     RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
     /* Free the existing local cdict (if any) to save memory. */
     ZSTD_clearAllDicts(cctx);
     cctx->cdict = cdict;
     return 0;
 }
 
 size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize)
 {
     return ZSTD_CCtx_refPrefix_advanced(cctx, prefix, prefixSize, ZSTD_dct_rawContent);
 }
 
 size_t ZSTD_CCtx_refPrefix_advanced(
         ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
 {
     RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
     ZSTD_clearAllDicts(cctx);
     cctx->prefixDict.dict = prefix;
     cctx->prefixDict.dictSize = prefixSize;
     cctx->prefixDict.dictContentType = dictContentType;
     return 0;
 }
 
 /*! ZSTD_CCtx_reset() :
  *  Also dumps dictionary */
 size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx, ZSTD_ResetDirective reset)
 {
     if ( (reset == ZSTD_reset_session_only)
       || (reset == ZSTD_reset_session_and_parameters) ) {
         cctx->streamStage = zcss_init;
         cctx->pledgedSrcSizePlusOne = 0;
     }
     if ( (reset == ZSTD_reset_parameters)
       || (reset == ZSTD_reset_session_and_parameters) ) {
         RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong);
         ZSTD_clearAllDicts(cctx);
         return ZSTD_CCtxParams_reset(&cctx->requestedParams);
     }
     return 0;
 }
 
 
 /** ZSTD_checkCParams() :
     control CParam values remain within authorized range.
     @return : 0, or an error code if one value is beyond authorized range */
 size_t ZSTD_checkCParams(ZSTD_compressionParameters cParams)
 {
     BOUNDCHECK(ZSTD_c_windowLog, (int)cParams.windowLog);
     BOUNDCHECK(ZSTD_c_chainLog,  (int)cParams.chainLog);
     BOUNDCHECK(ZSTD_c_hashLog,   (int)cParams.hashLog);
     BOUNDCHECK(ZSTD_c_searchLog, (int)cParams.searchLog);
     BOUNDCHECK(ZSTD_c_minMatch,  (int)cParams.minMatch);
     BOUNDCHECK(ZSTD_c_targetLength,(int)cParams.targetLength);
     BOUNDCHECK(ZSTD_c_strategy,  cParams.strategy);
     return 0;
 }
 
 /** ZSTD_clampCParams() :
  *  make CParam values within valid range.
  *  @return : valid CParams */
 static ZSTD_compressionParameters
 ZSTD_clampCParams(ZSTD_compressionParameters cParams)
 {
 #   define CLAMP_TYPE(cParam, val, type) {                                \
         ZSTD_bounds const bounds = ZSTD_cParam_getBounds(cParam);         \
         if ((int)valbounds.upperBound) val=(type)bounds.upperBound; \
     }
 #   define CLAMP(cParam, val) CLAMP_TYPE(cParam, val, unsigned)
     CLAMP(ZSTD_c_windowLog, cParams.windowLog);
     CLAMP(ZSTD_c_chainLog,  cParams.chainLog);
     CLAMP(ZSTD_c_hashLog,   cParams.hashLog);
     CLAMP(ZSTD_c_searchLog, cParams.searchLog);
     CLAMP(ZSTD_c_minMatch,  cParams.minMatch);
     CLAMP(ZSTD_c_targetLength,cParams.targetLength);
     CLAMP_TYPE(ZSTD_c_strategy,cParams.strategy, ZSTD_strategy);
     return cParams;
 }
 
 /** ZSTD_cycleLog() :
  *  condition for correct operation : hashLog > 1 */
 static U32 ZSTD_cycleLog(U32 hashLog, ZSTD_strategy strat)
 {
     U32 const btScale = ((U32)strat >= (U32)ZSTD_btlazy2);
     return hashLog - btScale;
 }
 
 /** ZSTD_adjustCParams_internal() :
  *  optimize `cPar` for a specified input (`srcSize` and `dictSize`).
  *  mostly downsize to reduce memory consumption and initialization latency.
  * `srcSize` can be ZSTD_CONTENTSIZE_UNKNOWN when not known.
  *  note : for the time being, `srcSize==0` means "unknown" too, for compatibility with older convention.
  *  condition : cPar is presumed validated (can be checked using ZSTD_checkCParams()). */
 static ZSTD_compressionParameters
 ZSTD_adjustCParams_internal(ZSTD_compressionParameters cPar,
                             unsigned long long srcSize,
                             size_t dictSize)
 {
     static const U64 minSrcSize = 513; /* (1<<9) + 1 */
     static const U64 maxWindowResize = 1ULL << (ZSTD_WINDOWLOG_MAX-1);
     assert(ZSTD_checkCParams(cPar)==0);
 
     if (dictSize && (srcSize+1<2) /* ZSTD_CONTENTSIZE_UNKNOWN and 0 mean "unknown" */ )
         srcSize = minSrcSize;  /* presumed small when there is a dictionary */
     else if (srcSize == 0)
         srcSize = ZSTD_CONTENTSIZE_UNKNOWN;  /* 0 == unknown : presumed large */
 
     /* resize windowLog if input is small enough, to use less memory */
     if ( (srcSize < maxWindowResize)
       && (dictSize < maxWindowResize) )  {
         U32 const tSize = (U32)(srcSize + dictSize);
         static U32 const hashSizeMin = 1 << ZSTD_HASHLOG_MIN;
         U32 const srcLog = (tSize < hashSizeMin) ? ZSTD_HASHLOG_MIN :
                             ZSTD_highbit32(tSize-1) + 1;
         if (cPar.windowLog > srcLog) cPar.windowLog = srcLog;
     }
     if (cPar.hashLog > cPar.windowLog+1) cPar.hashLog = cPar.windowLog+1;
     {   U32 const cycleLog = ZSTD_cycleLog(cPar.chainLog, cPar.strategy);
         if (cycleLog > cPar.windowLog)
             cPar.chainLog -= (cycleLog - cPar.windowLog);
     }
 
     if (cPar.windowLog < ZSTD_WINDOWLOG_ABSOLUTEMIN)
         cPar.windowLog = ZSTD_WINDOWLOG_ABSOLUTEMIN;  /* minimum wlog required for valid frame header */
 
     return cPar;
 }
 
 ZSTD_compressionParameters
 ZSTD_adjustCParams(ZSTD_compressionParameters cPar,
                    unsigned long long srcSize,
                    size_t dictSize)
 {
     cPar = ZSTD_clampCParams(cPar);   /* resulting cPar is necessarily valid (all parameters within range) */
     return ZSTD_adjustCParams_internal(cPar, srcSize, dictSize);
 }
 
 ZSTD_compressionParameters ZSTD_getCParamsFromCCtxParams(
         const ZSTD_CCtx_params* CCtxParams, U64 srcSizeHint, size_t dictSize)
 {
-    ZSTD_compressionParameters cParams = ZSTD_getCParams(CCtxParams->compressionLevel, srcSizeHint, dictSize);
+    ZSTD_compressionParameters cParams;
+    if (srcSizeHint == ZSTD_CONTENTSIZE_UNKNOWN && CCtxParams->srcSizeHint > 0) {
+      srcSizeHint = CCtxParams->srcSizeHint;
+    }
+    cParams = ZSTD_getCParams(CCtxParams->compressionLevel, srcSizeHint, dictSize);
     if (CCtxParams->ldmParams.enableLdm) cParams.windowLog = ZSTD_LDM_DEFAULT_WINDOW_LOG;
     if (CCtxParams->cParams.windowLog) cParams.windowLog = CCtxParams->cParams.windowLog;
     if (CCtxParams->cParams.hashLog) cParams.hashLog = CCtxParams->cParams.hashLog;
     if (CCtxParams->cParams.chainLog) cParams.chainLog = CCtxParams->cParams.chainLog;
     if (CCtxParams->cParams.searchLog) cParams.searchLog = CCtxParams->cParams.searchLog;
     if (CCtxParams->cParams.minMatch) cParams.minMatch = CCtxParams->cParams.minMatch;
     if (CCtxParams->cParams.targetLength) cParams.targetLength = CCtxParams->cParams.targetLength;
     if (CCtxParams->cParams.strategy) cParams.strategy = CCtxParams->cParams.strategy;
     assert(!ZSTD_checkCParams(cParams));
     return ZSTD_adjustCParams_internal(cParams, srcSizeHint, dictSize);
 }
 
 static size_t
 ZSTD_sizeof_matchState(const ZSTD_compressionParameters* const cParams,
                        const U32 forCCtx)
 {
     size_t const chainSize = (cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cParams->chainLog);
     size_t const hSize = ((size_t)1) << cParams->hashLog;
     U32    const hashLog3 = (forCCtx && cParams->minMatch==3) ? MIN(ZSTD_HASHLOG3_MAX, cParams->windowLog) : 0;
-    size_t const h3Size = ((size_t)1) << hashLog3;
-    size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
-    size_t const optPotentialSpace = ((MaxML+1) + (MaxLL+1) + (MaxOff+1) + (1<strategy >= ZSTD_btopt))
                                 ? optPotentialSpace
                                 : 0;
     DEBUGLOG(4, "chainSize: %u - hSize: %u - h3Size: %u",
                 (U32)chainSize, (U32)hSize, (U32)h3Size);
     return tableSpace + optSpace;
 }
 
 size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params)
 {
     RETURN_ERROR_IF(params->nbWorkers > 0, GENERIC, "Estimate CCtx size is supported for single-threaded compression only.");
     {   ZSTD_compressionParameters const cParams =
                 ZSTD_getCParamsFromCCtxParams(params, 0, 0);
         size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
         U32    const divider = (cParams.minMatch==3) ? 3 : 4;
         size_t const maxNbSeq = blockSize / divider;
-        size_t const tokenSpace = WILDCOPY_OVERLENGTH + blockSize + 11*maxNbSeq;
-        size_t const entropySpace = HUF_WORKSPACE_SIZE;
-        size_t const blockStateSpace = 2 * sizeof(ZSTD_compressedBlockState_t);
+        size_t const tokenSpace = ZSTD_cwksp_alloc_size(WILDCOPY_OVERLENGTH + blockSize)
+                                + ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(seqDef))
+                                + 3 * ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(BYTE));
+        size_t const entropySpace = ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE);
+        size_t const blockStateSpace = 2 * ZSTD_cwksp_alloc_size(sizeof(ZSTD_compressedBlockState_t));
         size_t const matchStateSize = ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 1);
 
         size_t const ldmSpace = ZSTD_ldm_getTableSize(params->ldmParams);
-        size_t const ldmSeqSpace = ZSTD_ldm_getMaxNbSeq(params->ldmParams, blockSize) * sizeof(rawSeq);
+        size_t const ldmSeqSpace = ZSTD_cwksp_alloc_size(ZSTD_ldm_getMaxNbSeq(params->ldmParams, blockSize) * sizeof(rawSeq));
 
         size_t const neededSpace = entropySpace + blockStateSpace + tokenSpace +
                                    matchStateSize + ldmSpace + ldmSeqSpace;
+        size_t const cctxSpace = ZSTD_cwksp_alloc_size(sizeof(ZSTD_CCtx));
 
-        DEBUGLOG(5, "sizeof(ZSTD_CCtx) : %u", (U32)sizeof(ZSTD_CCtx));
-        DEBUGLOG(5, "estimate workSpace : %u", (U32)neededSpace);
-        return sizeof(ZSTD_CCtx) + neededSpace;
+        DEBUGLOG(5, "sizeof(ZSTD_CCtx) : %u", (U32)cctxSpace);
+        DEBUGLOG(5, "estimate workspace : %u", (U32)neededSpace);
+        return cctxSpace + neededSpace;
     }
 }
 
 size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams)
 {
     ZSTD_CCtx_params const params = ZSTD_makeCCtxParamsFromCParams(cParams);
     return ZSTD_estimateCCtxSize_usingCCtxParams(¶ms);
 }
 
 static size_t ZSTD_estimateCCtxSize_internal(int compressionLevel)
 {
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, 0);
     return ZSTD_estimateCCtxSize_usingCParams(cParams);
 }
 
 size_t ZSTD_estimateCCtxSize(int compressionLevel)
 {
     int level;
     size_t memBudget = 0;
     for (level=MIN(compressionLevel, 1); level<=compressionLevel; level++) {
         size_t const newMB = ZSTD_estimateCCtxSize_internal(level);
         if (newMB > memBudget) memBudget = newMB;
     }
     return memBudget;
 }
 
 size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params)
 {
     RETURN_ERROR_IF(params->nbWorkers > 0, GENERIC, "Estimate CCtx size is supported for single-threaded compression only.");
     {   ZSTD_compressionParameters const cParams =
                 ZSTD_getCParamsFromCCtxParams(params, 0, 0);
         size_t const CCtxSize = ZSTD_estimateCCtxSize_usingCCtxParams(params);
         size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
         size_t const inBuffSize = ((size_t)1 << cParams.windowLog) + blockSize;
         size_t const outBuffSize = ZSTD_compressBound(blockSize) + 1;
-        size_t const streamingSize = inBuffSize + outBuffSize;
+        size_t const streamingSize = ZSTD_cwksp_alloc_size(inBuffSize)
+                                   + ZSTD_cwksp_alloc_size(outBuffSize);
 
         return CCtxSize + streamingSize;
     }
 }
 
 size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams)
 {
     ZSTD_CCtx_params const params = ZSTD_makeCCtxParamsFromCParams(cParams);
     return ZSTD_estimateCStreamSize_usingCCtxParams(¶ms);
 }
 
 static size_t ZSTD_estimateCStreamSize_internal(int compressionLevel)
 {
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, 0);
     return ZSTD_estimateCStreamSize_usingCParams(cParams);
 }
 
 size_t ZSTD_estimateCStreamSize(int compressionLevel)
 {
     int level;
     size_t memBudget = 0;
     for (level=MIN(compressionLevel, 1); level<=compressionLevel; level++) {
         size_t const newMB = ZSTD_estimateCStreamSize_internal(level);
         if (newMB > memBudget) memBudget = newMB;
     }
     return memBudget;
 }
 
 /* ZSTD_getFrameProgression():
  * tells how much data has been consumed (input) and produced (output) for current frame.
  * able to count progression inside worker threads (non-blocking mode).
  */
 ZSTD_frameProgression ZSTD_getFrameProgression(const ZSTD_CCtx* cctx)
 {
 #ifdef ZSTD_MULTITHREAD
     if (cctx->appliedParams.nbWorkers > 0) {
         return ZSTDMT_getFrameProgression(cctx->mtctx);
     }
 #endif
     {   ZSTD_frameProgression fp;
         size_t const buffered = (cctx->inBuff == NULL) ? 0 :
                                 cctx->inBuffPos - cctx->inToCompress;
         if (buffered) assert(cctx->inBuffPos >= cctx->inToCompress);
         assert(buffered <= ZSTD_BLOCKSIZE_MAX);
         fp.ingested = cctx->consumedSrcSize + buffered;
         fp.consumed = cctx->consumedSrcSize;
         fp.produced = cctx->producedCSize;
         fp.flushed  = cctx->producedCSize;   /* simplified; some data might still be left within streaming output buffer */
         fp.currentJobID = 0;
         fp.nbActiveWorkers = 0;
         return fp;
 }   }
 
 /*! ZSTD_toFlushNow()
  *  Only useful for multithreading scenarios currently (nbWorkers >= 1).
  */
 size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx)
 {
 #ifdef ZSTD_MULTITHREAD
     if (cctx->appliedParams.nbWorkers > 0) {
         return ZSTDMT_toFlushNow(cctx->mtctx);
     }
 #endif
     (void)cctx;
     return 0;   /* over-simplification; could also check if context is currently running in streaming mode, and in which case, report how many bytes are left to be flushed within output buffer */
 }
 
-
-
-static U32 ZSTD_equivalentCParams(ZSTD_compressionParameters cParams1,
-                                  ZSTD_compressionParameters cParams2)
-{
-    return (cParams1.hashLog  == cParams2.hashLog)
-         & (cParams1.chainLog == cParams2.chainLog)
-         & (cParams1.strategy == cParams2.strategy)   /* opt parser space */
-         & ((cParams1.minMatch==3) == (cParams2.minMatch==3));  /* hashlog3 space */
-}
-
 static void ZSTD_assertEqualCParams(ZSTD_compressionParameters cParams1,
                                     ZSTD_compressionParameters cParams2)
 {
     (void)cParams1;
     (void)cParams2;
     assert(cParams1.windowLog    == cParams2.windowLog);
     assert(cParams1.chainLog     == cParams2.chainLog);
     assert(cParams1.hashLog      == cParams2.hashLog);
     assert(cParams1.searchLog    == cParams2.searchLog);
     assert(cParams1.minMatch     == cParams2.minMatch);
     assert(cParams1.targetLength == cParams2.targetLength);
     assert(cParams1.strategy     == cParams2.strategy);
 }
 
-/** The parameters are equivalent if ldm is not enabled in both sets or
- *  all the parameters are equivalent. */
-static U32 ZSTD_equivalentLdmParams(ldmParams_t ldmParams1,
-                                    ldmParams_t ldmParams2)
-{
-    return (!ldmParams1.enableLdm && !ldmParams2.enableLdm) ||
-           (ldmParams1.enableLdm == ldmParams2.enableLdm &&
-            ldmParams1.hashLog == ldmParams2.hashLog &&
-            ldmParams1.bucketSizeLog == ldmParams2.bucketSizeLog &&
-            ldmParams1.minMatchLength == ldmParams2.minMatchLength &&
-            ldmParams1.hashRateLog == ldmParams2.hashRateLog);
-}
-
-typedef enum { ZSTDb_not_buffered, ZSTDb_buffered } ZSTD_buffered_policy_e;
-
-/* ZSTD_sufficientBuff() :
- * check internal buffers exist for streaming if buffPol == ZSTDb_buffered .
- * Note : they are assumed to be correctly sized if ZSTD_equivalentCParams()==1 */
-static U32 ZSTD_sufficientBuff(size_t bufferSize1, size_t maxNbSeq1,
-                            size_t maxNbLit1,
-                            ZSTD_buffered_policy_e buffPol2,
-                            ZSTD_compressionParameters cParams2,
-                            U64 pledgedSrcSize)
-{
-    size_t const windowSize2 = MAX(1, (size_t)MIN(((U64)1 << cParams2.windowLog), pledgedSrcSize));
-    size_t const blockSize2 = MIN(ZSTD_BLOCKSIZE_MAX, windowSize2);
-    size_t const maxNbSeq2 = blockSize2 / ((cParams2.minMatch == 3) ? 3 : 4);
-    size_t const maxNbLit2 = blockSize2;
-    size_t const neededBufferSize2 = (buffPol2==ZSTDb_buffered) ? windowSize2 + blockSize2 : 0;
-    DEBUGLOG(4, "ZSTD_sufficientBuff: is neededBufferSize2=%u <= bufferSize1=%u",
-                (U32)neededBufferSize2, (U32)bufferSize1);
-    DEBUGLOG(4, "ZSTD_sufficientBuff: is maxNbSeq2=%u <= maxNbSeq1=%u",
-                (U32)maxNbSeq2, (U32)maxNbSeq1);
-    DEBUGLOG(4, "ZSTD_sufficientBuff: is maxNbLit2=%u <= maxNbLit1=%u",
-                (U32)maxNbLit2, (U32)maxNbLit1);
-    return (maxNbLit2 <= maxNbLit1)
-         & (maxNbSeq2 <= maxNbSeq1)
-         & (neededBufferSize2 <= bufferSize1);
-}
-
-/** Equivalence for resetCCtx purposes */
-static U32 ZSTD_equivalentParams(ZSTD_CCtx_params params1,
-                                 ZSTD_CCtx_params params2,
-                                 size_t buffSize1,
-                                 size_t maxNbSeq1, size_t maxNbLit1,
-                                 ZSTD_buffered_policy_e buffPol2,
-                                 U64 pledgedSrcSize)
-{
-    DEBUGLOG(4, "ZSTD_equivalentParams: pledgedSrcSize=%u", (U32)pledgedSrcSize);
-    if (!ZSTD_equivalentCParams(params1.cParams, params2.cParams)) {
-      DEBUGLOG(4, "ZSTD_equivalentCParams() == 0");
-      return 0;
-    }
-    if (!ZSTD_equivalentLdmParams(params1.ldmParams, params2.ldmParams)) {
-      DEBUGLOG(4, "ZSTD_equivalentLdmParams() == 0");
-      return 0;
-    }
-    if (!ZSTD_sufficientBuff(buffSize1, maxNbSeq1, maxNbLit1, buffPol2,
-                             params2.cParams, pledgedSrcSize)) {
-      DEBUGLOG(4, "ZSTD_sufficientBuff() == 0");
-      return 0;
-    }
-    return 1;
-}
-
 static void ZSTD_reset_compressedBlockState(ZSTD_compressedBlockState_t* bs)
 {
     int i;
     for (i = 0; i < ZSTD_REP_NUM; ++i)
         bs->rep[i] = repStartValue[i];
     bs->entropy.huf.repeatMode = HUF_repeat_none;
     bs->entropy.fse.offcode_repeatMode = FSE_repeat_none;
     bs->entropy.fse.matchlength_repeatMode = FSE_repeat_none;
     bs->entropy.fse.litlength_repeatMode = FSE_repeat_none;
 }
 
 /*! ZSTD_invalidateMatchState()
  *  Invalidate all the matches in the match finder tables.
  *  Requires nextSrc and base to be set (can be NULL).
  */
 static void ZSTD_invalidateMatchState(ZSTD_matchState_t* ms)
 {
     ZSTD_window_clear(&ms->window);
 
     ms->nextToUpdate = ms->window.dictLimit;
     ms->loadedDictEnd = 0;
     ms->opt.litLengthSum = 0;  /* force reset of btopt stats */
     ms->dictMatchState = NULL;
 }
 
-/*! ZSTD_continueCCtx() :
- *  reuse CCtx without reset (note : requires no dictionary) */
-static size_t ZSTD_continueCCtx(ZSTD_CCtx* cctx, ZSTD_CCtx_params params, U64 pledgedSrcSize)
-{
-    size_t const windowSize = MAX(1, (size_t)MIN(((U64)1 << params.cParams.windowLog), pledgedSrcSize));
-    size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
-    DEBUGLOG(4, "ZSTD_continueCCtx: re-use context in place");
+/**
+ * Indicates whether this compression proceeds directly from user-provided
+ * source buffer to user-provided destination buffer (ZSTDb_not_buffered), or
+ * whether the context needs to buffer the input/output (ZSTDb_buffered).
+ */
+typedef enum {
+    ZSTDb_not_buffered,
+    ZSTDb_buffered
+} ZSTD_buffered_policy_e;
 
-    cctx->blockSize = blockSize;   /* previous block size could be different even for same windowLog, due to pledgedSrcSize */
-    cctx->appliedParams = params;
-    cctx->blockState.matchState.cParams = params.cParams;
-    cctx->pledgedSrcSizePlusOne = pledgedSrcSize+1;
-    cctx->consumedSrcSize = 0;
-    cctx->producedCSize = 0;
-    if (pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN)
-        cctx->appliedParams.fParams.contentSizeFlag = 0;
-    DEBUGLOG(4, "pledged content size : %u ; flag : %u",
-        (U32)pledgedSrcSize, cctx->appliedParams.fParams.contentSizeFlag);
-    cctx->stage = ZSTDcs_init;
-    cctx->dictID = 0;
-    if (params.ldmParams.enableLdm)
-        ZSTD_window_clear(&cctx->ldmState.window);
-    ZSTD_referenceExternalSequences(cctx, NULL, 0);
-    ZSTD_invalidateMatchState(&cctx->blockState.matchState);
-    ZSTD_reset_compressedBlockState(cctx->blockState.prevCBlock);
-    XXH64_reset(&cctx->xxhState, 0);
-    return 0;
-}
+/**
+ * Controls, for this matchState reset, whether the tables need to be cleared /
+ * prepared for the coming compression (ZSTDcrp_makeClean), or whether the
+ * tables can be left unclean (ZSTDcrp_leaveDirty), because we know that a
+ * subsequent operation will overwrite the table space anyways (e.g., copying
+ * the matchState contents in from a CDict).
+ */
+typedef enum {
+    ZSTDcrp_makeClean,
+    ZSTDcrp_leaveDirty
+} ZSTD_compResetPolicy_e;
 
-typedef enum { ZSTDcrp_continue, ZSTDcrp_noMemset } ZSTD_compResetPolicy_e;
+/**
+ * Controls, for this matchState reset, whether indexing can continue where it
+ * left off (ZSTDirp_continue), or whether it needs to be restarted from zero
+ * (ZSTDirp_reset).
+ */
+typedef enum {
+    ZSTDirp_continue,
+    ZSTDirp_reset
+} ZSTD_indexResetPolicy_e;
 
-typedef enum { ZSTD_resetTarget_CDict, ZSTD_resetTarget_CCtx } ZSTD_resetTarget_e;
+typedef enum {
+    ZSTD_resetTarget_CDict,
+    ZSTD_resetTarget_CCtx
+} ZSTD_resetTarget_e;
 
-static void*
+static size_t
 ZSTD_reset_matchState(ZSTD_matchState_t* ms,
-                      void* ptr,
+                      ZSTD_cwksp* ws,
                 const ZSTD_compressionParameters* cParams,
-                      ZSTD_compResetPolicy_e const crp, ZSTD_resetTarget_e const forWho)
+                const ZSTD_compResetPolicy_e crp,
+                const ZSTD_indexResetPolicy_e forceResetIndex,
+                const ZSTD_resetTarget_e forWho)
 {
     size_t const chainSize = (cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cParams->chainLog);
     size_t const hSize = ((size_t)1) << cParams->hashLog;
     U32    const hashLog3 = ((forWho == ZSTD_resetTarget_CCtx) && cParams->minMatch==3) ? MIN(ZSTD_HASHLOG3_MAX, cParams->windowLog) : 0;
-    size_t const h3Size = ((size_t)1) << hashLog3;
-    size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
+    size_t const h3Size = hashLog3 ? ((size_t)1) << hashLog3 : 0;
 
-    assert(((size_t)ptr & 3) == 0);
+    DEBUGLOG(4, "reset indices : %u", forceResetIndex == ZSTDirp_reset);
+    if (forceResetIndex == ZSTDirp_reset) {
+        memset(&ms->window, 0, sizeof(ms->window));
+        ms->window.dictLimit = 1;    /* start from 1, so that 1st position is valid */
+        ms->window.lowLimit = 1;     /* it ensures first and later CCtx usages compress the same */
+        ms->window.nextSrc = ms->window.base + 1;   /* see issue #1241 */
+        ZSTD_cwksp_mark_tables_dirty(ws);
+    }
 
     ms->hashLog3 = hashLog3;
-    memset(&ms->window, 0, sizeof(ms->window));
-    ms->window.dictLimit = 1;    /* start from 1, so that 1st position is valid */
-    ms->window.lowLimit = 1;     /* it ensures first and later CCtx usages compress the same */
-    ms->window.nextSrc = ms->window.base + 1;   /* see issue #1241 */
+
     ZSTD_invalidateMatchState(ms);
 
+    assert(!ZSTD_cwksp_reserve_failed(ws)); /* check that allocation hasn't already failed */
+
+    ZSTD_cwksp_clear_tables(ws);
+
+    DEBUGLOG(5, "reserving table space");
+    /* table Space */
+    ms->hashTable = (U32*)ZSTD_cwksp_reserve_table(ws, hSize * sizeof(U32));
+    ms->chainTable = (U32*)ZSTD_cwksp_reserve_table(ws, chainSize * sizeof(U32));
+    ms->hashTable3 = (U32*)ZSTD_cwksp_reserve_table(ws, h3Size * sizeof(U32));
+    RETURN_ERROR_IF(ZSTD_cwksp_reserve_failed(ws), memory_allocation,
+                    "failed a workspace allocation in ZSTD_reset_matchState");
+
+    DEBUGLOG(4, "reset table : %u", crp!=ZSTDcrp_leaveDirty);
+    if (crp!=ZSTDcrp_leaveDirty) {
+        /* reset tables only */
+        ZSTD_cwksp_clean_tables(ws);
+    }
+
     /* opt parser space */
     if ((forWho == ZSTD_resetTarget_CCtx) && (cParams->strategy >= ZSTD_btopt)) {
         DEBUGLOG(4, "reserving optimal parser space");
-        ms->opt.litFreq = (unsigned*)ptr;
-        ms->opt.litLengthFreq = ms->opt.litFreq + (1<opt.matchLengthFreq = ms->opt.litLengthFreq + (MaxLL+1);
-        ms->opt.offCodeFreq = ms->opt.matchLengthFreq + (MaxML+1);
-        ptr = ms->opt.offCodeFreq + (MaxOff+1);
-        ms->opt.matchTable = (ZSTD_match_t*)ptr;
-        ptr = ms->opt.matchTable + ZSTD_OPT_NUM+1;
-        ms->opt.priceTable = (ZSTD_optimal_t*)ptr;
-        ptr = ms->opt.priceTable + ZSTD_OPT_NUM+1;
+        ms->opt.litFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (1<opt.litLengthFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxLL+1) * sizeof(unsigned));
+        ms->opt.matchLengthFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxML+1) * sizeof(unsigned));
+        ms->opt.offCodeFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxOff+1) * sizeof(unsigned));
+        ms->opt.matchTable = (ZSTD_match_t*)ZSTD_cwksp_reserve_aligned(ws, (ZSTD_OPT_NUM+1) * sizeof(ZSTD_match_t));
+        ms->opt.priceTable = (ZSTD_optimal_t*)ZSTD_cwksp_reserve_aligned(ws, (ZSTD_OPT_NUM+1) * sizeof(ZSTD_optimal_t));
     }
 
-    /* table Space */
-    DEBUGLOG(4, "reset table : %u", crp!=ZSTDcrp_noMemset);
-    assert(((size_t)ptr & 3) == 0);  /* ensure ptr is properly aligned */
-    if (crp!=ZSTDcrp_noMemset) memset(ptr, 0, tableSpace);   /* reset tables only */
-    ms->hashTable = (U32*)(ptr);
-    ms->chainTable = ms->hashTable + hSize;
-    ms->hashTable3 = ms->chainTable + chainSize;
-    ptr = ms->hashTable3 + h3Size;
-
     ms->cParams = *cParams;
 
-    assert(((size_t)ptr & 3) == 0);
-    return ptr;
+    RETURN_ERROR_IF(ZSTD_cwksp_reserve_failed(ws), memory_allocation,
+                    "failed a workspace allocation in ZSTD_reset_matchState");
+
+    return 0;
 }
 
 /* ZSTD_indexTooCloseToMax() :
  * minor optimization : prefer memset() rather than reduceIndex()
  * which is measurably slow in some circumstances (reported for Visual Studio).
  * Works when re-using a context for a lot of smallish inputs :
  * if all inputs are smaller than ZSTD_INDEXOVERFLOW_MARGIN,
  * memset() will be triggered before reduceIndex().
  */
 #define ZSTD_INDEXOVERFLOW_MARGIN (16 MB)
 static int ZSTD_indexTooCloseToMax(ZSTD_window_t w)
 {
     return (size_t)(w.nextSrc - w.base) > (ZSTD_CURRENT_MAX - ZSTD_INDEXOVERFLOW_MARGIN);
 }
 
-#define ZSTD_WORKSPACETOOLARGE_FACTOR 3 /* define "workspace is too large" as this number of times larger than needed */
-#define ZSTD_WORKSPACETOOLARGE_MAXDURATION 128  /* when workspace is continuously too large
-                                         * during at least this number of times,
-                                         * context's memory usage is considered wasteful,
-                                         * because it's sized to handle a worst case scenario which rarely happens.
-                                         * In which case, resize it down to free some memory */
-
 /*! ZSTD_resetCCtx_internal() :
     note : `params` are assumed fully validated at this stage */
 static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
                                       ZSTD_CCtx_params params,
                                       U64 const pledgedSrcSize,
                                       ZSTD_compResetPolicy_e const crp,
                                       ZSTD_buffered_policy_e const zbuff)
 {
+    ZSTD_cwksp* const ws = &zc->workspace;
     DEBUGLOG(4, "ZSTD_resetCCtx_internal: pledgedSrcSize=%u, wlog=%u",
                 (U32)pledgedSrcSize, params.cParams.windowLog);
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
 
-    if (crp == ZSTDcrp_continue) {
-        if (ZSTD_equivalentParams(zc->appliedParams, params,
-                                  zc->inBuffSize,
-                                  zc->seqStore.maxNbSeq, zc->seqStore.maxNbLit,
-                                  zbuff, pledgedSrcSize) ) {
-            DEBUGLOG(4, "ZSTD_equivalentParams()==1 -> consider continue mode");
-            zc->workSpaceOversizedDuration += (zc->workSpaceOversizedDuration > 0);   /* if it was too large, it still is */
-            if (zc->workSpaceOversizedDuration <= ZSTD_WORKSPACETOOLARGE_MAXDURATION) {
-                DEBUGLOG(4, "continue mode confirmed (wLog1=%u, blockSize1=%zu)",
-                            zc->appliedParams.cParams.windowLog, zc->blockSize);
-                if (ZSTD_indexTooCloseToMax(zc->blockState.matchState.window)) {
-                    /* prefer a reset, faster than a rescale */
-                    ZSTD_reset_matchState(&zc->blockState.matchState,
-                                           zc->entropyWorkspace + HUF_WORKSPACE_SIZE_U32,
-                                          ¶ms.cParams,
-                                           crp, ZSTD_resetTarget_CCtx);
-                }
-                return ZSTD_continueCCtx(zc, params, pledgedSrcSize);
-    }   }   }
-    DEBUGLOG(4, "ZSTD_equivalentParams()==0 -> reset CCtx");
+    zc->isFirstBlock = 1;
 
     if (params.ldmParams.enableLdm) {
         /* Adjust long distance matching parameters */
         ZSTD_ldm_adjustParameters(¶ms.ldmParams, ¶ms.cParams);
         assert(params.ldmParams.hashLog >= params.ldmParams.bucketSizeLog);
         assert(params.ldmParams.hashRateLog < 32);
         zc->ldmState.hashPower = ZSTD_rollingHash_primePower(params.ldmParams.minMatchLength);
     }
 
     {   size_t const windowSize = MAX(1, (size_t)MIN(((U64)1 << params.cParams.windowLog), pledgedSrcSize));
         size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
         U32    const divider = (params.cParams.minMatch==3) ? 3 : 4;
         size_t const maxNbSeq = blockSize / divider;
-        size_t const tokenSpace = WILDCOPY_OVERLENGTH + blockSize + 11*maxNbSeq;
+        size_t const tokenSpace = ZSTD_cwksp_alloc_size(WILDCOPY_OVERLENGTH + blockSize)
+                                + ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(seqDef))
+                                + 3 * ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(BYTE));
         size_t const buffOutSize = (zbuff==ZSTDb_buffered) ? ZSTD_compressBound(blockSize)+1 : 0;
         size_t const buffInSize = (zbuff==ZSTDb_buffered) ? windowSize + blockSize : 0;
         size_t const matchStateSize = ZSTD_sizeof_matchState(¶ms.cParams, /* forCCtx */ 1);
         size_t const maxNbLdmSeq = ZSTD_ldm_getMaxNbSeq(params.ldmParams, blockSize);
-        void* ptr;   /* used to partition workSpace */
 
-        /* Check if workSpace is large enough, alloc a new one if needed */
-        {   size_t const entropySpace = HUF_WORKSPACE_SIZE;
-            size_t const blockStateSpace = 2 * sizeof(ZSTD_compressedBlockState_t);
-            size_t const bufferSpace = buffInSize + buffOutSize;
+        ZSTD_indexResetPolicy_e needsIndexReset = ZSTDirp_continue;
+
+        if (ZSTD_indexTooCloseToMax(zc->blockState.matchState.window)) {
+            needsIndexReset = ZSTDirp_reset;
+        }
+
+        ZSTD_cwksp_bump_oversized_duration(ws, 0);
+
+        /* Check if workspace is large enough, alloc a new one if needed */
+        {   size_t const cctxSpace = zc->staticSize ? ZSTD_cwksp_alloc_size(sizeof(ZSTD_CCtx)) : 0;
+            size_t const entropySpace = ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE);
+            size_t const blockStateSpace = 2 * ZSTD_cwksp_alloc_size(sizeof(ZSTD_compressedBlockState_t));
+            size_t const bufferSpace = ZSTD_cwksp_alloc_size(buffInSize) + ZSTD_cwksp_alloc_size(buffOutSize);
             size_t const ldmSpace = ZSTD_ldm_getTableSize(params.ldmParams);
-            size_t const ldmSeqSpace = maxNbLdmSeq * sizeof(rawSeq);
+            size_t const ldmSeqSpace = ZSTD_cwksp_alloc_size(maxNbLdmSeq * sizeof(rawSeq));
 
-            size_t const neededSpace = entropySpace + blockStateSpace + ldmSpace +
-                                       ldmSeqSpace + matchStateSize + tokenSpace +
-                                       bufferSpace;
+            size_t const neededSpace =
+                cctxSpace +
+                entropySpace +
+                blockStateSpace +
+                ldmSpace +
+                ldmSeqSpace +
+                matchStateSize +
+                tokenSpace +
+                bufferSpace;
 
-            int const workSpaceTooSmall = zc->workSpaceSize < neededSpace;
-            int const workSpaceTooLarge = zc->workSpaceSize > ZSTD_WORKSPACETOOLARGE_FACTOR * neededSpace;
-            int const workSpaceWasteful = workSpaceTooLarge && (zc->workSpaceOversizedDuration > ZSTD_WORKSPACETOOLARGE_MAXDURATION);
-            zc->workSpaceOversizedDuration = workSpaceTooLarge ? zc->workSpaceOversizedDuration+1 : 0;
+            int const workspaceTooSmall = ZSTD_cwksp_sizeof(ws) < neededSpace;
+            int const workspaceWasteful = ZSTD_cwksp_check_wasteful(ws, neededSpace);
 
             DEBUGLOG(4, "Need %zuKB workspace, including %zuKB for match state, and %zuKB for buffers",
                         neededSpace>>10, matchStateSize>>10, bufferSpace>>10);
             DEBUGLOG(4, "windowSize: %zu - blockSize: %zu", windowSize, blockSize);
 
-            if (workSpaceTooSmall || workSpaceWasteful) {
-                DEBUGLOG(4, "Resize workSpaceSize from %zuKB to %zuKB",
-                            zc->workSpaceSize >> 10,
+            if (workspaceTooSmall || workspaceWasteful) {
+                DEBUGLOG(4, "Resize workspaceSize from %zuKB to %zuKB",
+                            ZSTD_cwksp_sizeof(ws) >> 10,
                             neededSpace >> 10);
 
                 RETURN_ERROR_IF(zc->staticSize, memory_allocation, "static cctx : no resize");
 
-                zc->workSpaceSize = 0;
-                ZSTD_free(zc->workSpace, zc->customMem);
-                zc->workSpace = ZSTD_malloc(neededSpace, zc->customMem);
-                RETURN_ERROR_IF(zc->workSpace == NULL, memory_allocation);
-                zc->workSpaceSize = neededSpace;
-                zc->workSpaceOversizedDuration = 0;
+                needsIndexReset = ZSTDirp_reset;
 
+                ZSTD_cwksp_free(ws, zc->customMem);
+                FORWARD_IF_ERROR(ZSTD_cwksp_create(ws, neededSpace, zc->customMem));
+
+                DEBUGLOG(5, "reserving object space");
                 /* Statically sized space.
                  * entropyWorkspace never moves,
                  * though prev/next block swap places */
-                assert(((size_t)zc->workSpace & 3) == 0);   /* ensure correct alignment */
-                assert(zc->workSpaceSize >= 2 * sizeof(ZSTD_compressedBlockState_t));
-                zc->blockState.prevCBlock = (ZSTD_compressedBlockState_t*)zc->workSpace;
-                zc->blockState.nextCBlock = zc->blockState.prevCBlock + 1;
-                ptr = zc->blockState.nextCBlock + 1;
-                zc->entropyWorkspace = (U32*)ptr;
+                assert(ZSTD_cwksp_check_available(ws, 2 * sizeof(ZSTD_compressedBlockState_t)));
+                zc->blockState.prevCBlock = (ZSTD_compressedBlockState_t*) ZSTD_cwksp_reserve_object(ws, sizeof(ZSTD_compressedBlockState_t));
+                RETURN_ERROR_IF(zc->blockState.prevCBlock == NULL, memory_allocation, "couldn't allocate prevCBlock");
+                zc->blockState.nextCBlock = (ZSTD_compressedBlockState_t*) ZSTD_cwksp_reserve_object(ws, sizeof(ZSTD_compressedBlockState_t));
+                RETURN_ERROR_IF(zc->blockState.nextCBlock == NULL, memory_allocation, "couldn't allocate nextCBlock");
+                zc->entropyWorkspace = (U32*) ZSTD_cwksp_reserve_object(ws, HUF_WORKSPACE_SIZE);
+                RETURN_ERROR_IF(zc->blockState.nextCBlock == NULL, memory_allocation, "couldn't allocate entropyWorkspace");
         }   }
 
+        ZSTD_cwksp_clear(ws);
+
         /* init params */
         zc->appliedParams = params;
         zc->blockState.matchState.cParams = params.cParams;
         zc->pledgedSrcSizePlusOne = pledgedSrcSize+1;
         zc->consumedSrcSize = 0;
         zc->producedCSize = 0;
         if (pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN)
             zc->appliedParams.fParams.contentSizeFlag = 0;
         DEBUGLOG(4, "pledged content size : %u ; flag : %u",
             (unsigned)pledgedSrcSize, zc->appliedParams.fParams.contentSizeFlag);
         zc->blockSize = blockSize;
 
         XXH64_reset(&zc->xxhState, 0);
         zc->stage = ZSTDcs_init;
         zc->dictID = 0;
 
         ZSTD_reset_compressedBlockState(zc->blockState.prevCBlock);
 
-        ptr = ZSTD_reset_matchState(&zc->blockState.matchState,
-                                     zc->entropyWorkspace + HUF_WORKSPACE_SIZE_U32,
-                                    ¶ms.cParams,
-                                     crp, ZSTD_resetTarget_CCtx);
-
-        /* ldm hash table */
-        /* initialize bucketOffsets table later for pointer alignment */
-        if (params.ldmParams.enableLdm) {
-            size_t const ldmHSize = ((size_t)1) << params.ldmParams.hashLog;
-            memset(ptr, 0, ldmHSize * sizeof(ldmEntry_t));
-            assert(((size_t)ptr & 3) == 0); /* ensure ptr is properly aligned */
-            zc->ldmState.hashTable = (ldmEntry_t*)ptr;
-            ptr = zc->ldmState.hashTable + ldmHSize;
-            zc->ldmSequences = (rawSeq*)ptr;
-            ptr = zc->ldmSequences + maxNbLdmSeq;
-            zc->maxNbLdmSequences = maxNbLdmSeq;
-
-            memset(&zc->ldmState.window, 0, sizeof(zc->ldmState.window));
-        }
-        assert(((size_t)ptr & 3) == 0); /* ensure ptr is properly aligned */
-
-        /* sequences storage */
-        zc->seqStore.maxNbSeq = maxNbSeq;
-        zc->seqStore.sequencesStart = (seqDef*)ptr;
-        ptr = zc->seqStore.sequencesStart + maxNbSeq;
-        zc->seqStore.llCode = (BYTE*) ptr;
-        zc->seqStore.mlCode = zc->seqStore.llCode + maxNbSeq;
-        zc->seqStore.ofCode = zc->seqStore.mlCode + maxNbSeq;
-        zc->seqStore.litStart = zc->seqStore.ofCode + maxNbSeq;
         /* ZSTD_wildcopy() is used to copy into the literals buffer,
          * so we have to oversize the buffer by WILDCOPY_OVERLENGTH bytes.
          */
+        zc->seqStore.litStart = ZSTD_cwksp_reserve_buffer(ws, blockSize + WILDCOPY_OVERLENGTH);
         zc->seqStore.maxNbLit = blockSize;
-        ptr = zc->seqStore.litStart + blockSize + WILDCOPY_OVERLENGTH;
 
+        /* buffers */
+        zc->inBuffSize = buffInSize;
+        zc->inBuff = (char*)ZSTD_cwksp_reserve_buffer(ws, buffInSize);
+        zc->outBuffSize = buffOutSize;
+        zc->outBuff = (char*)ZSTD_cwksp_reserve_buffer(ws, buffOutSize);
+
         /* ldm bucketOffsets table */
         if (params.ldmParams.enableLdm) {
+            /* TODO: avoid memset? */
             size_t const ldmBucketSize =
                   ((size_t)1) << (params.ldmParams.hashLog -
                                   params.ldmParams.bucketSizeLog);
-            memset(ptr, 0, ldmBucketSize);
-            zc->ldmState.bucketOffsets = (BYTE*)ptr;
-            ptr = zc->ldmState.bucketOffsets + ldmBucketSize;
-            ZSTD_window_clear(&zc->ldmState.window);
+            zc->ldmState.bucketOffsets = ZSTD_cwksp_reserve_buffer(ws, ldmBucketSize);
+            memset(zc->ldmState.bucketOffsets, 0, ldmBucketSize);
         }
+
+        /* sequences storage */
         ZSTD_referenceExternalSequences(zc, NULL, 0);
+        zc->seqStore.maxNbSeq = maxNbSeq;
+        zc->seqStore.llCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
+        zc->seqStore.mlCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
+        zc->seqStore.ofCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
+        zc->seqStore.sequencesStart = (seqDef*)ZSTD_cwksp_reserve_aligned(ws, maxNbSeq * sizeof(seqDef));
 
-        /* buffers */
-        zc->inBuffSize = buffInSize;
-        zc->inBuff = (char*)ptr;
-        zc->outBuffSize = buffOutSize;
-        zc->outBuff = zc->inBuff + buffInSize;
+        FORWARD_IF_ERROR(ZSTD_reset_matchState(
+            &zc->blockState.matchState,
+            ws,
+            ¶ms.cParams,
+            crp,
+            needsIndexReset,
+            ZSTD_resetTarget_CCtx));
 
+        /* ldm hash table */
+        if (params.ldmParams.enableLdm) {
+            /* TODO: avoid memset? */
+            size_t const ldmHSize = ((size_t)1) << params.ldmParams.hashLog;
+            zc->ldmState.hashTable = (ldmEntry_t*)ZSTD_cwksp_reserve_aligned(ws, ldmHSize * sizeof(ldmEntry_t));
+            memset(zc->ldmState.hashTable, 0, ldmHSize * sizeof(ldmEntry_t));
+            zc->ldmSequences = (rawSeq*)ZSTD_cwksp_reserve_aligned(ws, maxNbLdmSeq * sizeof(rawSeq));
+            zc->maxNbLdmSequences = maxNbLdmSeq;
+
+            memset(&zc->ldmState.window, 0, sizeof(zc->ldmState.window));
+            ZSTD_window_clear(&zc->ldmState.window);
+        }
+
+        DEBUGLOG(3, "wksp: finished allocating, %zd bytes remain available", ZSTD_cwksp_available_space(ws));
+
         return 0;
     }
 }
 
 /* ZSTD_invalidateRepCodes() :
  * ensures next compression will not use repcodes from previous block.
  * Note : only works with regular variant;
  *        do not use with extDict variant ! */
 void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx) {
     int i;
     for (i=0; iblockState.prevCBlock->rep[i] = 0;
     assert(!ZSTD_window_hasExtDict(cctx->blockState.matchState.window));
 }
 
 /* These are the approximate sizes for each strategy past which copying the
  * dictionary tables into the working context is faster than using them
  * in-place.
  */
 static const size_t attachDictSizeCutoffs[ZSTD_STRATEGY_MAX+1] = {
     8 KB,  /* unused */
     8 KB,  /* ZSTD_fast */
     16 KB, /* ZSTD_dfast */
     32 KB, /* ZSTD_greedy */
     32 KB, /* ZSTD_lazy */
     32 KB, /* ZSTD_lazy2 */
     32 KB, /* ZSTD_btlazy2 */
     32 KB, /* ZSTD_btopt */
     8 KB,  /* ZSTD_btultra */
     8 KB   /* ZSTD_btultra2 */
 };
 
 static int ZSTD_shouldAttachDict(const ZSTD_CDict* cdict,
-                                 ZSTD_CCtx_params params,
+                                 const ZSTD_CCtx_params* params,
                                  U64 pledgedSrcSize)
 {
     size_t cutoff = attachDictSizeCutoffs[cdict->matchState.cParams.strategy];
     return ( pledgedSrcSize <= cutoff
           || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
-          || params.attachDictPref == ZSTD_dictForceAttach )
-        && params.attachDictPref != ZSTD_dictForceCopy
-        && !params.forceWindow; /* dictMatchState isn't correctly
+          || params->attachDictPref == ZSTD_dictForceAttach )
+        && params->attachDictPref != ZSTD_dictForceCopy
+        && !params->forceWindow; /* dictMatchState isn't correctly
                                  * handled in _enforceMaxDist */
 }
 
 static size_t
 ZSTD_resetCCtx_byAttachingCDict(ZSTD_CCtx* cctx,
                         const ZSTD_CDict* cdict,
                         ZSTD_CCtx_params params,
                         U64 pledgedSrcSize,
                         ZSTD_buffered_policy_e zbuff)
 {
     {   const ZSTD_compressionParameters* const cdict_cParams = &cdict->matchState.cParams;
         unsigned const windowLog = params.cParams.windowLog;
         assert(windowLog != 0);
         /* Resize working context table params for input only, since the dict
          * has its own tables. */
         params.cParams = ZSTD_adjustCParams_internal(*cdict_cParams, pledgedSrcSize, 0);
         params.cParams.windowLog = windowLog;
-        ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
-                                ZSTDcrp_continue, zbuff);
+        FORWARD_IF_ERROR(ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
+                                                 ZSTDcrp_makeClean, zbuff));
         assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
     }
 
     {   const U32 cdictEnd = (U32)( cdict->matchState.window.nextSrc
                                   - cdict->matchState.window.base);
         const U32 cdictLen = cdictEnd - cdict->matchState.window.dictLimit;
         if (cdictLen == 0) {
             /* don't even attach dictionaries with no contents */
             DEBUGLOG(4, "skipping attaching empty dictionary");
         } else {
             DEBUGLOG(4, "attaching dictionary into context");
             cctx->blockState.matchState.dictMatchState = &cdict->matchState;
 
             /* prep working match state so dict matches never have negative indices
              * when they are translated to the working context's index space. */
             if (cctx->blockState.matchState.window.dictLimit < cdictEnd) {
                 cctx->blockState.matchState.window.nextSrc =
                     cctx->blockState.matchState.window.base + cdictEnd;
                 ZSTD_window_clear(&cctx->blockState.matchState.window);
             }
             /* loadedDictEnd is expressed within the referential of the active context */
             cctx->blockState.matchState.loadedDictEnd = cctx->blockState.matchState.window.dictLimit;
     }   }
 
     cctx->dictID = cdict->dictID;
 
     /* copy block state */
     memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
 
     return 0;
 }
 
 static size_t ZSTD_resetCCtx_byCopyingCDict(ZSTD_CCtx* cctx,
                             const ZSTD_CDict* cdict,
                             ZSTD_CCtx_params params,
                             U64 pledgedSrcSize,
                             ZSTD_buffered_policy_e zbuff)
 {
     const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
 
     DEBUGLOG(4, "copying dictionary into context");
 
     {   unsigned const windowLog = params.cParams.windowLog;
         assert(windowLog != 0);
         /* Copy only compression parameters related to tables. */
         params.cParams = *cdict_cParams;
         params.cParams.windowLog = windowLog;
-        ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
-                                ZSTDcrp_noMemset, zbuff);
+        FORWARD_IF_ERROR(ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
+                                                 ZSTDcrp_leaveDirty, zbuff));
         assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
         assert(cctx->appliedParams.cParams.hashLog == cdict_cParams->hashLog);
         assert(cctx->appliedParams.cParams.chainLog == cdict_cParams->chainLog);
     }
 
+    ZSTD_cwksp_mark_tables_dirty(&cctx->workspace);
+
     /* copy tables */
     {   size_t const chainSize = (cdict_cParams->strategy == ZSTD_fast) ? 0 : ((size_t)1 << cdict_cParams->chainLog);
         size_t const hSize =  (size_t)1 << cdict_cParams->hashLog;
-        size_t const tableSpace = (chainSize + hSize) * sizeof(U32);
-        assert((U32*)cctx->blockState.matchState.chainTable == (U32*)cctx->blockState.matchState.hashTable + hSize);  /* chainTable must follow hashTable */
-        assert((U32*)cctx->blockState.matchState.hashTable3 == (U32*)cctx->blockState.matchState.chainTable + chainSize);
-        assert((U32*)cdict->matchState.chainTable == (U32*)cdict->matchState.hashTable + hSize);  /* chainTable must follow hashTable */
-        assert((U32*)cdict->matchState.hashTable3 == (U32*)cdict->matchState.chainTable + chainSize);
-        memcpy(cctx->blockState.matchState.hashTable, cdict->matchState.hashTable, tableSpace);   /* presumes all tables follow each other */
+
+        memcpy(cctx->blockState.matchState.hashTable,
+               cdict->matchState.hashTable,
+               hSize * sizeof(U32));
+        memcpy(cctx->blockState.matchState.chainTable,
+               cdict->matchState.chainTable,
+               chainSize * sizeof(U32));
     }
 
     /* Zero the hashTable3, since the cdict never fills it */
-    {   size_t const h3Size = (size_t)1 << cctx->blockState.matchState.hashLog3;
+    {   int const h3log = cctx->blockState.matchState.hashLog3;
+        size_t const h3Size = h3log ? ((size_t)1 << h3log) : 0;
         assert(cdict->matchState.hashLog3 == 0);
         memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
     }
 
+    ZSTD_cwksp_mark_tables_clean(&cctx->workspace);
+
     /* copy dictionary offsets */
     {   ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
         ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
         dstMatchState->window       = srcMatchState->window;
         dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
         dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
     }
 
     cctx->dictID = cdict->dictID;
 
     /* copy block state */
     memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
 
     return 0;
 }
 
 /* We have a choice between copying the dictionary context into the working
  * context, or referencing the dictionary context from the working context
  * in-place. We decide here which strategy to use. */
 static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
                             const ZSTD_CDict* cdict,
-                            ZSTD_CCtx_params params,
+                            const ZSTD_CCtx_params* params,
                             U64 pledgedSrcSize,
                             ZSTD_buffered_policy_e zbuff)
 {
 
     DEBUGLOG(4, "ZSTD_resetCCtx_usingCDict (pledgedSrcSize=%u)",
                 (unsigned)pledgedSrcSize);
 
     if (ZSTD_shouldAttachDict(cdict, params, pledgedSrcSize)) {
         return ZSTD_resetCCtx_byAttachingCDict(
-            cctx, cdict, params, pledgedSrcSize, zbuff);
+            cctx, cdict, *params, pledgedSrcSize, zbuff);
     } else {
         return ZSTD_resetCCtx_byCopyingCDict(
-            cctx, cdict, params, pledgedSrcSize, zbuff);
+            cctx, cdict, *params, pledgedSrcSize, zbuff);
     }
 }
 
 /*! ZSTD_copyCCtx_internal() :
  *  Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
  *  Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
  *  The "context", in this case, refers to the hash and chain tables,
  *  entropy tables, and dictionary references.
  * `windowLog` value is enforced if != 0, otherwise value is copied from srcCCtx.
  * @return : 0, or an error code */
 static size_t ZSTD_copyCCtx_internal(ZSTD_CCtx* dstCCtx,
                             const ZSTD_CCtx* srcCCtx,
                             ZSTD_frameParameters fParams,
                             U64 pledgedSrcSize,
                             ZSTD_buffered_policy_e zbuff)
 {
     DEBUGLOG(5, "ZSTD_copyCCtx_internal");
     RETURN_ERROR_IF(srcCCtx->stage!=ZSTDcs_init, stage_wrong);
 
     memcpy(&dstCCtx->customMem, &srcCCtx->customMem, sizeof(ZSTD_customMem));
     {   ZSTD_CCtx_params params = dstCCtx->requestedParams;
         /* Copy only compression parameters related to tables. */
         params.cParams = srcCCtx->appliedParams.cParams;
         params.fParams = fParams;
         ZSTD_resetCCtx_internal(dstCCtx, params, pledgedSrcSize,
-                                ZSTDcrp_noMemset, zbuff);
+                                ZSTDcrp_leaveDirty, zbuff);
         assert(dstCCtx->appliedParams.cParams.windowLog == srcCCtx->appliedParams.cParams.windowLog);
         assert(dstCCtx->appliedParams.cParams.strategy == srcCCtx->appliedParams.cParams.strategy);
         assert(dstCCtx->appliedParams.cParams.hashLog == srcCCtx->appliedParams.cParams.hashLog);
         assert(dstCCtx->appliedParams.cParams.chainLog == srcCCtx->appliedParams.cParams.chainLog);
         assert(dstCCtx->blockState.matchState.hashLog3 == srcCCtx->blockState.matchState.hashLog3);
     }
 
+    ZSTD_cwksp_mark_tables_dirty(&dstCCtx->workspace);
+
     /* copy tables */
     {   size_t const chainSize = (srcCCtx->appliedParams.cParams.strategy == ZSTD_fast) ? 0 : ((size_t)1 << srcCCtx->appliedParams.cParams.chainLog);
         size_t const hSize =  (size_t)1 << srcCCtx->appliedParams.cParams.hashLog;
-        size_t const h3Size = (size_t)1 << srcCCtx->blockState.matchState.hashLog3;
-        size_t const tableSpace = (chainSize + hSize + h3Size) * sizeof(U32);
-        assert((U32*)dstCCtx->blockState.matchState.chainTable == (U32*)dstCCtx->blockState.matchState.hashTable + hSize);  /* chainTable must follow hashTable */
-        assert((U32*)dstCCtx->blockState.matchState.hashTable3 == (U32*)dstCCtx->blockState.matchState.chainTable + chainSize);
-        memcpy(dstCCtx->blockState.matchState.hashTable, srcCCtx->blockState.matchState.hashTable, tableSpace);   /* presumes all tables follow each other */
+        int const h3log = srcCCtx->blockState.matchState.hashLog3;
+        size_t const h3Size = h3log ? ((size_t)1 << h3log) : 0;
+
+        memcpy(dstCCtx->blockState.matchState.hashTable,
+               srcCCtx->blockState.matchState.hashTable,
+               hSize * sizeof(U32));
+        memcpy(dstCCtx->blockState.matchState.chainTable,
+               srcCCtx->blockState.matchState.chainTable,
+               chainSize * sizeof(U32));
+        memcpy(dstCCtx->blockState.matchState.hashTable3,
+               srcCCtx->blockState.matchState.hashTable3,
+               h3Size * sizeof(U32));
     }
 
+    ZSTD_cwksp_mark_tables_clean(&dstCCtx->workspace);
+
     /* copy dictionary offsets */
     {
         const ZSTD_matchState_t* srcMatchState = &srcCCtx->blockState.matchState;
         ZSTD_matchState_t* dstMatchState = &dstCCtx->blockState.matchState;
         dstMatchState->window       = srcMatchState->window;
         dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
         dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
     }
     dstCCtx->dictID = srcCCtx->dictID;
 
     /* copy block state */
     memcpy(dstCCtx->blockState.prevCBlock, srcCCtx->blockState.prevCBlock, sizeof(*srcCCtx->blockState.prevCBlock));
 
     return 0;
 }
 
 /*! ZSTD_copyCCtx() :
  *  Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
  *  Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
  *  pledgedSrcSize==0 means "unknown".
 *   @return : 0, or an error code */
 size_t ZSTD_copyCCtx(ZSTD_CCtx* dstCCtx, const ZSTD_CCtx* srcCCtx, unsigned long long pledgedSrcSize)
 {
     ZSTD_frameParameters fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
     ZSTD_buffered_policy_e const zbuff = (ZSTD_buffered_policy_e)(srcCCtx->inBuffSize>0);
     ZSTD_STATIC_ASSERT((U32)ZSTDb_buffered==1);
     if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;
     fParams.contentSizeFlag = (pledgedSrcSize != ZSTD_CONTENTSIZE_UNKNOWN);
 
     return ZSTD_copyCCtx_internal(dstCCtx, srcCCtx,
                                 fParams, pledgedSrcSize,
                                 zbuff);
 }
 
 
 #define ZSTD_ROWSIZE 16
 /*! ZSTD_reduceTable() :
  *  reduce table indexes by `reducerValue`, or squash to zero.
  *  PreserveMark preserves "unsorted mark" for btlazy2 strategy.
  *  It must be set to a clear 0/1 value, to remove branch during inlining.
  *  Presume table size is a multiple of ZSTD_ROWSIZE
  *  to help auto-vectorization */
 FORCE_INLINE_TEMPLATE void
 ZSTD_reduceTable_internal (U32* const table, U32 const size, U32 const reducerValue, int const preserveMark)
 {
     int const nbRows = (int)size / ZSTD_ROWSIZE;
     int cellNb = 0;
     int rowNb;
     assert((size & (ZSTD_ROWSIZE-1)) == 0);  /* multiple of ZSTD_ROWSIZE */
     assert(size < (1U<<31));   /* can be casted to int */
+
+#if defined (MEMORY_SANITIZER) && !defined (ZSTD_MSAN_DONT_POISON_WORKSPACE)
+    /* To validate that the table re-use logic is sound, and that we don't
+     * access table space that we haven't cleaned, we re-"poison" the table
+     * space every time we mark it dirty.
+     *
+     * This function however is intended to operate on those dirty tables and
+     * re-clean them. So when this function is used correctly, we can unpoison
+     * the memory it operated on. This introduces a blind spot though, since
+     * if we now try to operate on __actually__ poisoned memory, we will not
+     * detect that. */
+    __msan_unpoison(table, size * sizeof(U32));
+#endif
+
     for (rowNb=0 ; rowNb < nbRows ; rowNb++) {
         int column;
         for (column=0; columncParams.hashLog;
         ZSTD_reduceTable(ms->hashTable, hSize, reducerValue);
     }
 
     if (params->cParams.strategy != ZSTD_fast) {
         U32 const chainSize = (U32)1 << params->cParams.chainLog;
         if (params->cParams.strategy == ZSTD_btlazy2)
             ZSTD_reduceTable_btlazy2(ms->chainTable, chainSize, reducerValue);
         else
             ZSTD_reduceTable(ms->chainTable, chainSize, reducerValue);
     }
 
     if (ms->hashLog3) {
         U32 const h3Size = (U32)1 << ms->hashLog3;
         ZSTD_reduceTable(ms->hashTable3, h3Size, reducerValue);
     }
 }
 
 
 /*-*******************************************************
 *  Block entropic compression
 *********************************************************/
 
 /* See doc/zstd_compression_format.md for detailed format description */
 
 static size_t ZSTD_noCompressBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize, U32 lastBlock)
 {
     U32 const cBlockHeader24 = lastBlock + (((U32)bt_raw)<<1) + (U32)(srcSize << 3);
     RETURN_ERROR_IF(srcSize + ZSTD_blockHeaderSize > dstCapacity,
                     dstSize_tooSmall);
     MEM_writeLE24(dst, cBlockHeader24);
     memcpy((BYTE*)dst + ZSTD_blockHeaderSize, src, srcSize);
     return ZSTD_blockHeaderSize + srcSize;
 }
 
 void ZSTD_seqToCodes(const seqStore_t* seqStorePtr)
 {
     const seqDef* const sequences = seqStorePtr->sequencesStart;
     BYTE* const llCodeTable = seqStorePtr->llCode;
     BYTE* const ofCodeTable = seqStorePtr->ofCode;
     BYTE* const mlCodeTable = seqStorePtr->mlCode;
     U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
     U32 u;
     assert(nbSeq <= seqStorePtr->maxNbSeq);
     for (u=0; ulongLengthID==1)
         llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
     if (seqStorePtr->longLengthID==2)
         mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
 }
 
 static int ZSTD_disableLiteralsCompression(const ZSTD_CCtx_params* cctxParams)
 {
     switch (cctxParams->literalCompressionMode) {
     case ZSTD_lcm_huffman:
         return 0;
     case ZSTD_lcm_uncompressed:
         return 1;
     default:
         assert(0 /* impossible: pre-validated */);
         /* fall-through */
     case ZSTD_lcm_auto:
         return (cctxParams->cParams.strategy == ZSTD_fast) && (cctxParams->cParams.targetLength > 0);
     }
 }
 
 /* ZSTD_compressSequences_internal():
  * actually compresses both literals and sequences */
 MEM_STATIC size_t
 ZSTD_compressSequences_internal(seqStore_t* seqStorePtr,
                           const ZSTD_entropyCTables_t* prevEntropy,
                                 ZSTD_entropyCTables_t* nextEntropy,
                           const ZSTD_CCtx_params* cctxParams,
                                 void* dst, size_t dstCapacity,
-                                void* workspace, size_t wkspSize,
+                                void* entropyWorkspace, size_t entropyWkspSize,
                           const int bmi2)
 {
     const int longOffsets = cctxParams->cParams.windowLog > STREAM_ACCUMULATOR_MIN;
     ZSTD_strategy const strategy = cctxParams->cParams.strategy;
     unsigned count[MaxSeq+1];
     FSE_CTable* CTable_LitLength = nextEntropy->fse.litlengthCTable;
     FSE_CTable* CTable_OffsetBits = nextEntropy->fse.offcodeCTable;
     FSE_CTable* CTable_MatchLength = nextEntropy->fse.matchlengthCTable;
     U32 LLtype, Offtype, MLtype;   /* compressed, raw or rle */
     const seqDef* const sequences = seqStorePtr->sequencesStart;
     const BYTE* const ofCodeTable = seqStorePtr->ofCode;
     const BYTE* const llCodeTable = seqStorePtr->llCode;
     const BYTE* const mlCodeTable = seqStorePtr->mlCode;
     BYTE* const ostart = (BYTE*)dst;
     BYTE* const oend = ostart + dstCapacity;
     BYTE* op = ostart;
-    size_t const nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
+    size_t const nbSeq = (size_t)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
     BYTE* seqHead;
     BYTE* lastNCount = NULL;
 
     DEBUGLOG(5, "ZSTD_compressSequences_internal (nbSeq=%zu)", nbSeq);
     ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1<litStart;
-        size_t const litSize = seqStorePtr->lit - literals;
+        size_t const litSize = (size_t)(seqStorePtr->lit - literals);
         size_t const cSize = ZSTD_compressLiterals(
                                     &prevEntropy->huf, &nextEntropy->huf,
                                     cctxParams->cParams.strategy,
                                     ZSTD_disableLiteralsCompression(cctxParams),
                                     op, dstCapacity,
                                     literals, litSize,
-                                    workspace, wkspSize,
+                                    entropyWorkspace, entropyWkspSize,
                                     bmi2);
         FORWARD_IF_ERROR(cSize);
         assert(cSize <= dstCapacity);
         op += cSize;
     }
 
     /* Sequences Header */
     RETURN_ERROR_IF((oend-op) < 3 /*max nbSeq Size*/ + 1 /*seqHead*/,
                     dstSize_tooSmall);
-    if (nbSeq < 0x7F)
+    if (nbSeq < 128) {
         *op++ = (BYTE)nbSeq;
-    else if (nbSeq < LONGNBSEQ)
-        op[0] = (BYTE)((nbSeq>>8) + 0x80), op[1] = (BYTE)nbSeq, op+=2;
-    else
-        op[0]=0xFF, MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ)), op+=3;
+    } else if (nbSeq < LONGNBSEQ) {
+        op[0] = (BYTE)((nbSeq>>8) + 0x80);
+        op[1] = (BYTE)nbSeq;
+        op+=2;
+    } else {
+        op[0]=0xFF;
+        MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ));
+        op+=3;
+    }
     assert(op <= oend);
     if (nbSeq==0) {
         /* Copy the old tables over as if we repeated them */
         memcpy(&nextEntropy->fse, &prevEntropy->fse, sizeof(prevEntropy->fse));
-        return op - ostart;
+        return (size_t)(op - ostart);
     }
 
     /* seqHead : flags for FSE encoding type */
     seqHead = op++;
     assert(op <= oend);
 
     /* convert length/distances into codes */
     ZSTD_seqToCodes(seqStorePtr);
     /* build CTable for Literal Lengths */
     {   unsigned max = MaxLL;
-        size_t const mostFrequent = HIST_countFast_wksp(count, &max, llCodeTable, nbSeq, workspace, wkspSize);   /* can't fail */
+        size_t const mostFrequent = HIST_countFast_wksp(count, &max, llCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);   /* can't fail */
         DEBUGLOG(5, "Building LL table");
         nextEntropy->fse.litlength_repeatMode = prevEntropy->fse.litlength_repeatMode;
         LLtype = ZSTD_selectEncodingType(&nextEntropy->fse.litlength_repeatMode,
                                         count, max, mostFrequent, nbSeq,
                                         LLFSELog, prevEntropy->fse.litlengthCTable,
                                         LL_defaultNorm, LL_defaultNormLog,
                                         ZSTD_defaultAllowed, strategy);
         assert(set_basic < set_compressed && set_rle < set_compressed);
         assert(!(LLtype < set_compressed && nextEntropy->fse.litlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
-        {   size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_LitLength, LLFSELog, (symbolEncodingType_e)LLtype,
-                                                    count, max, llCodeTable, nbSeq, LL_defaultNorm, LL_defaultNormLog, MaxLL,
-                                                    prevEntropy->fse.litlengthCTable, sizeof(prevEntropy->fse.litlengthCTable),
-                                                    workspace, wkspSize);
+        {   size_t const countSize = ZSTD_buildCTable(
+                op, (size_t)(oend - op),
+                CTable_LitLength, LLFSELog, (symbolEncodingType_e)LLtype,
+                count, max, llCodeTable, nbSeq,
+                LL_defaultNorm, LL_defaultNormLog, MaxLL,
+                prevEntropy->fse.litlengthCTable,
+                sizeof(prevEntropy->fse.litlengthCTable),
+                entropyWorkspace, entropyWkspSize);
             FORWARD_IF_ERROR(countSize);
             if (LLtype == set_compressed)
                 lastNCount = op;
             op += countSize;
             assert(op <= oend);
     }   }
     /* build CTable for Offsets */
     {   unsigned max = MaxOff;
-        size_t const mostFrequent = HIST_countFast_wksp(count, &max, ofCodeTable, nbSeq, workspace, wkspSize);  /* can't fail */
+        size_t const mostFrequent = HIST_countFast_wksp(
+            count, &max, ofCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);  /* can't fail */
         /* We can only use the basic table if max <= DefaultMaxOff, otherwise the offsets are too large */
         ZSTD_defaultPolicy_e const defaultPolicy = (max <= DefaultMaxOff) ? ZSTD_defaultAllowed : ZSTD_defaultDisallowed;
         DEBUGLOG(5, "Building OF table");
         nextEntropy->fse.offcode_repeatMode = prevEntropy->fse.offcode_repeatMode;
         Offtype = ZSTD_selectEncodingType(&nextEntropy->fse.offcode_repeatMode,
                                         count, max, mostFrequent, nbSeq,
                                         OffFSELog, prevEntropy->fse.offcodeCTable,
                                         OF_defaultNorm, OF_defaultNormLog,
                                         defaultPolicy, strategy);
         assert(!(Offtype < set_compressed && nextEntropy->fse.offcode_repeatMode != FSE_repeat_none)); /* We don't copy tables */
-        {   size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_OffsetBits, OffFSELog, (symbolEncodingType_e)Offtype,
-                                                    count, max, ofCodeTable, nbSeq, OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
-                                                    prevEntropy->fse.offcodeCTable, sizeof(prevEntropy->fse.offcodeCTable),
-                                                    workspace, wkspSize);
+        {   size_t const countSize = ZSTD_buildCTable(
+                op, (size_t)(oend - op),
+                CTable_OffsetBits, OffFSELog, (symbolEncodingType_e)Offtype,
+                count, max, ofCodeTable, nbSeq,
+                OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
+                prevEntropy->fse.offcodeCTable,
+                sizeof(prevEntropy->fse.offcodeCTable),
+                entropyWorkspace, entropyWkspSize);
             FORWARD_IF_ERROR(countSize);
             if (Offtype == set_compressed)
                 lastNCount = op;
             op += countSize;
             assert(op <= oend);
     }   }
     /* build CTable for MatchLengths */
     {   unsigned max = MaxML;
-        size_t const mostFrequent = HIST_countFast_wksp(count, &max, mlCodeTable, nbSeq, workspace, wkspSize);   /* can't fail */
+        size_t const mostFrequent = HIST_countFast_wksp(
+            count, &max, mlCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);   /* can't fail */
         DEBUGLOG(5, "Building ML table (remaining space : %i)", (int)(oend-op));
         nextEntropy->fse.matchlength_repeatMode = prevEntropy->fse.matchlength_repeatMode;
         MLtype = ZSTD_selectEncodingType(&nextEntropy->fse.matchlength_repeatMode,
                                         count, max, mostFrequent, nbSeq,
                                         MLFSELog, prevEntropy->fse.matchlengthCTable,
                                         ML_defaultNorm, ML_defaultNormLog,
                                         ZSTD_defaultAllowed, strategy);
         assert(!(MLtype < set_compressed && nextEntropy->fse.matchlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
-        {   size_t const countSize = ZSTD_buildCTable(op, oend - op, CTable_MatchLength, MLFSELog, (symbolEncodingType_e)MLtype,
-                                                    count, max, mlCodeTable, nbSeq, ML_defaultNorm, ML_defaultNormLog, MaxML,
-                                                    prevEntropy->fse.matchlengthCTable, sizeof(prevEntropy->fse.matchlengthCTable),
-                                                    workspace, wkspSize);
+        {   size_t const countSize = ZSTD_buildCTable(
+                op, (size_t)(oend - op),
+                CTable_MatchLength, MLFSELog, (symbolEncodingType_e)MLtype,
+                count, max, mlCodeTable, nbSeq,
+                ML_defaultNorm, ML_defaultNormLog, MaxML,
+                prevEntropy->fse.matchlengthCTable,
+                sizeof(prevEntropy->fse.matchlengthCTable),
+                entropyWorkspace, entropyWkspSize);
             FORWARD_IF_ERROR(countSize);
             if (MLtype == set_compressed)
                 lastNCount = op;
             op += countSize;
             assert(op <= oend);
     }   }
 
     *seqHead = (BYTE)((LLtype<<6) + (Offtype<<4) + (MLtype<<2));
 
     {   size_t const bitstreamSize = ZSTD_encodeSequences(
-                                        op, oend - op,
+                                        op, (size_t)(oend - op),
                                         CTable_MatchLength, mlCodeTable,
                                         CTable_OffsetBits, ofCodeTable,
                                         CTable_LitLength, llCodeTable,
                                         sequences, nbSeq,
                                         longOffsets, bmi2);
         FORWARD_IF_ERROR(bitstreamSize);
         op += bitstreamSize;
         assert(op <= oend);
         /* zstd versions <= 1.3.4 mistakenly report corruption when
          * FSE_readNCount() receives a buffer < 4 bytes.
          * Fixed by https://github.com/facebook/zstd/pull/1146.
          * This can happen when the last set_compressed table present is 2
          * bytes and the bitstream is only one byte.
          * In this exceedingly rare case, we will simply emit an uncompressed
          * block, since it isn't worth optimizing.
          */
         if (lastNCount && (op - lastNCount) < 4) {
             /* NCountSize >= 2 && bitstreamSize > 0 ==> lastCountSize == 3 */
             assert(op - lastNCount == 3);
             DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.3.4 by "
                         "emitting an uncompressed block.");
             return 0;
         }
     }
 
     DEBUGLOG(5, "compressed block size : %u", (unsigned)(op - ostart));
-    return op - ostart;
+    return (size_t)(op - ostart);
 }
 
 MEM_STATIC size_t
 ZSTD_compressSequences(seqStore_t* seqStorePtr,
                        const ZSTD_entropyCTables_t* prevEntropy,
                              ZSTD_entropyCTables_t* nextEntropy,
                        const ZSTD_CCtx_params* cctxParams,
                              void* dst, size_t dstCapacity,
                              size_t srcSize,
-                             void* workspace, size_t wkspSize,
+                             void* entropyWorkspace, size_t entropyWkspSize,
                              int bmi2)
 {
     size_t const cSize = ZSTD_compressSequences_internal(
                             seqStorePtr, prevEntropy, nextEntropy, cctxParams,
                             dst, dstCapacity,
-                            workspace, wkspSize, bmi2);
+                            entropyWorkspace, entropyWkspSize, bmi2);
     if (cSize == 0) return 0;
     /* When srcSize <= dstCapacity, there is enough space to write a raw uncompressed block.
      * Since we ran out of space, block must be not compressible, so fall back to raw uncompressed block.
      */
     if ((cSize == ERROR(dstSize_tooSmall)) & (srcSize <= dstCapacity))
         return 0;  /* block not compressed */
     FORWARD_IF_ERROR(cSize);
 
     /* Check compressibility */
     {   size_t const maxCSize = srcSize - ZSTD_minGain(srcSize, cctxParams->cParams.strategy);
         if (cSize >= maxCSize) return 0;  /* block not compressed */
     }
 
     return cSize;
 }
 
 /* ZSTD_selectBlockCompressor() :
  * Not static, but internal use only (used by long distance matcher)
  * assumption : strat is a valid strategy */
 ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, ZSTD_dictMode_e dictMode)
 {
     static const ZSTD_blockCompressor blockCompressor[3][ZSTD_STRATEGY_MAX+1] = {
         { ZSTD_compressBlock_fast  /* default for 0 */,
           ZSTD_compressBlock_fast,
           ZSTD_compressBlock_doubleFast,
           ZSTD_compressBlock_greedy,
           ZSTD_compressBlock_lazy,
           ZSTD_compressBlock_lazy2,
           ZSTD_compressBlock_btlazy2,
           ZSTD_compressBlock_btopt,
           ZSTD_compressBlock_btultra,
           ZSTD_compressBlock_btultra2 },
         { ZSTD_compressBlock_fast_extDict  /* default for 0 */,
           ZSTD_compressBlock_fast_extDict,
           ZSTD_compressBlock_doubleFast_extDict,
           ZSTD_compressBlock_greedy_extDict,
           ZSTD_compressBlock_lazy_extDict,
           ZSTD_compressBlock_lazy2_extDict,
           ZSTD_compressBlock_btlazy2_extDict,
           ZSTD_compressBlock_btopt_extDict,
           ZSTD_compressBlock_btultra_extDict,
           ZSTD_compressBlock_btultra_extDict },
         { ZSTD_compressBlock_fast_dictMatchState  /* default for 0 */,
           ZSTD_compressBlock_fast_dictMatchState,
           ZSTD_compressBlock_doubleFast_dictMatchState,
           ZSTD_compressBlock_greedy_dictMatchState,
           ZSTD_compressBlock_lazy_dictMatchState,
           ZSTD_compressBlock_lazy2_dictMatchState,
           ZSTD_compressBlock_btlazy2_dictMatchState,
           ZSTD_compressBlock_btopt_dictMatchState,
           ZSTD_compressBlock_btultra_dictMatchState,
           ZSTD_compressBlock_btultra_dictMatchState }
     };
     ZSTD_blockCompressor selectedCompressor;
     ZSTD_STATIC_ASSERT((unsigned)ZSTD_fast == 1);
 
     assert(ZSTD_cParam_withinBounds(ZSTD_c_strategy, strat));
     selectedCompressor = blockCompressor[(int)dictMode][(int)strat];
     assert(selectedCompressor != NULL);
     return selectedCompressor;
 }
 
 static void ZSTD_storeLastLiterals(seqStore_t* seqStorePtr,
                                    const BYTE* anchor, size_t lastLLSize)
 {
     memcpy(seqStorePtr->lit, anchor, lastLLSize);
     seqStorePtr->lit += lastLLSize;
 }
 
 void ZSTD_resetSeqStore(seqStore_t* ssPtr)
 {
     ssPtr->lit = ssPtr->litStart;
     ssPtr->sequences = ssPtr->sequencesStart;
     ssPtr->longLengthID = 0;
 }
 
 typedef enum { ZSTDbss_compress, ZSTDbss_noCompress } ZSTD_buildSeqStore_e;
 
 static size_t ZSTD_buildSeqStore(ZSTD_CCtx* zc, const void* src, size_t srcSize)
 {
     ZSTD_matchState_t* const ms = &zc->blockState.matchState;
     DEBUGLOG(5, "ZSTD_buildSeqStore (srcSize=%zu)", srcSize);
     assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
     /* Assert that we have correctly flushed the ctx params into the ms's copy */
     ZSTD_assertEqualCParams(zc->appliedParams.cParams, ms->cParams);
     if (srcSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) {
         ZSTD_ldm_skipSequences(&zc->externSeqStore, srcSize, zc->appliedParams.cParams.minMatch);
         return ZSTDbss_noCompress; /* don't even attempt compression below a certain srcSize */
     }
     ZSTD_resetSeqStore(&(zc->seqStore));
     /* required for optimal parser to read stats from dictionary */
     ms->opt.symbolCosts = &zc->blockState.prevCBlock->entropy;
     /* tell the optimal parser how we expect to compress literals */
     ms->opt.literalCompressionMode = zc->appliedParams.literalCompressionMode;
     /* a gap between an attached dict and the current window is not safe,
      * they must remain adjacent,
      * and when that stops being the case, the dict must be unset */
     assert(ms->dictMatchState == NULL || ms->loadedDictEnd == ms->window.dictLimit);
 
     /* limited update after a very long match */
     {   const BYTE* const base = ms->window.base;
         const BYTE* const istart = (const BYTE*)src;
         const U32 current = (U32)(istart-base);
         if (sizeof(ptrdiff_t)==8) assert(istart - base < (ptrdiff_t)(U32)(-1));   /* ensure no overflow */
         if (current > ms->nextToUpdate + 384)
             ms->nextToUpdate = current - MIN(192, (U32)(current - ms->nextToUpdate - 384));
     }
 
     /* select and store sequences */
     {   ZSTD_dictMode_e const dictMode = ZSTD_matchState_dictMode(ms);
         size_t lastLLSize;
         {   int i;
             for (i = 0; i < ZSTD_REP_NUM; ++i)
                 zc->blockState.nextCBlock->rep[i] = zc->blockState.prevCBlock->rep[i];
         }
         if (zc->externSeqStore.pos < zc->externSeqStore.size) {
             assert(!zc->appliedParams.ldmParams.enableLdm);
             /* Updates ldmSeqStore.pos */
             lastLLSize =
                 ZSTD_ldm_blockCompress(&zc->externSeqStore,
                                        ms, &zc->seqStore,
                                        zc->blockState.nextCBlock->rep,
                                        src, srcSize);
             assert(zc->externSeqStore.pos <= zc->externSeqStore.size);
         } else if (zc->appliedParams.ldmParams.enableLdm) {
             rawSeqStore_t ldmSeqStore = {NULL, 0, 0, 0};
 
             ldmSeqStore.seq = zc->ldmSequences;
             ldmSeqStore.capacity = zc->maxNbLdmSequences;
             /* Updates ldmSeqStore.size */
             FORWARD_IF_ERROR(ZSTD_ldm_generateSequences(&zc->ldmState, &ldmSeqStore,
                                                &zc->appliedParams.ldmParams,
                                                src, srcSize));
             /* Updates ldmSeqStore.pos */
             lastLLSize =
                 ZSTD_ldm_blockCompress(&ldmSeqStore,
                                        ms, &zc->seqStore,
                                        zc->blockState.nextCBlock->rep,
                                        src, srcSize);
             assert(ldmSeqStore.pos == ldmSeqStore.size);
         } else {   /* not long range mode */
             ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->appliedParams.cParams.strategy, dictMode);
             lastLLSize = blockCompressor(ms, &zc->seqStore, zc->blockState.nextCBlock->rep, src, srcSize);
         }
         {   const BYTE* const lastLiterals = (const BYTE*)src + srcSize - lastLLSize;
             ZSTD_storeLastLiterals(&zc->seqStore, lastLiterals, lastLLSize);
     }   }
     return ZSTDbss_compress;
 }
 
+static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
+{
+    const seqStore_t* seqStore = ZSTD_getSeqStore(zc);
+    const seqDef* seqs = seqStore->sequencesStart;
+    size_t seqsSize = seqStore->sequences - seqs;
+
+    ZSTD_Sequence* outSeqs = &zc->seqCollector.seqStart[zc->seqCollector.seqIndex];
+    size_t i; size_t position; int repIdx;
+
+    assert(zc->seqCollector.seqIndex + 1 < zc->seqCollector.maxSequences);
+    for (i = 0, position = 0; i < seqsSize; ++i) {
+        outSeqs[i].offset = seqs[i].offset;
+        outSeqs[i].litLength = seqs[i].litLength;
+        outSeqs[i].matchLength = seqs[i].matchLength + MINMATCH;
+
+        if (i == seqStore->longLengthPos) {
+            if (seqStore->longLengthID == 1) {
+                outSeqs[i].litLength += 0x10000;
+            } else if (seqStore->longLengthID == 2) {
+                outSeqs[i].matchLength += 0x10000;
+            }
+        }
+
+        if (outSeqs[i].offset <= ZSTD_REP_NUM) {
+            outSeqs[i].rep = outSeqs[i].offset;
+            repIdx = (unsigned int)i - outSeqs[i].offset;
+
+            if (outSeqs[i].litLength == 0) {
+                if (outSeqs[i].offset < 3) {
+                    --repIdx;
+                } else {
+                    repIdx = (unsigned int)i - 1;
+                }
+                ++outSeqs[i].rep;
+            }
+            assert(repIdx >= -3);
+            outSeqs[i].offset = repIdx >= 0 ? outSeqs[repIdx].offset : repStartValue[-repIdx - 1];
+            if (outSeqs[i].rep == 4) {
+                --outSeqs[i].offset;
+            }
+        } else {
+            outSeqs[i].offset -= ZSTD_REP_NUM;
+        }
+
+        position += outSeqs[i].litLength;
+        outSeqs[i].matchPos = (unsigned int)position;
+        position += outSeqs[i].matchLength;
+    }
+    zc->seqCollector.seqIndex += seqsSize;
+}
+
+size_t ZSTD_getSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
+    size_t outSeqsSize, const void* src, size_t srcSize)
+{
+    const size_t dstCapacity = ZSTD_compressBound(srcSize);
+    void* dst = ZSTD_malloc(dstCapacity, ZSTD_defaultCMem);
+    SeqCollector seqCollector;
+
+    RETURN_ERROR_IF(dst == NULL, memory_allocation);
+
+    seqCollector.collectSequences = 1;
+    seqCollector.seqStart = outSeqs;
+    seqCollector.seqIndex = 0;
+    seqCollector.maxSequences = outSeqsSize;
+    zc->seqCollector = seqCollector;
+
+    ZSTD_compress2(zc, dst, dstCapacity, src, srcSize);
+    ZSTD_free(dst, ZSTD_defaultCMem);
+    return zc->seqCollector.seqIndex;
+}
+
+/* Returns true if the given block is a RLE block */
+static int ZSTD_isRLE(const BYTE *ip, size_t length) {
+    size_t i;
+    if (length < 2) return 1;
+    for (i = 1; i < length; ++i) {
+        if (ip[0] != ip[i]) return 0;
+    }
+    return 1;
+}
+
 static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
                                         void* dst, size_t dstCapacity,
-                                        const void* src, size_t srcSize)
+                                        const void* src, size_t srcSize, U32 frame)
 {
+    /* This the upper bound for the length of an rle block.
+     * This isn't the actual upper bound. Finding the real threshold
+     * needs further investigation.
+     */
+    const U32 rleMaxLength = 25;
     size_t cSize;
+    const BYTE* ip = (const BYTE*)src;
+    BYTE* op = (BYTE*)dst;
     DEBUGLOG(5, "ZSTD_compressBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
-                (unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit, (unsigned)zc->blockState.matchState.nextToUpdate);
+                (unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit,
+                (unsigned)zc->blockState.matchState.nextToUpdate);
 
     {   const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
         FORWARD_IF_ERROR(bss);
         if (bss == ZSTDbss_noCompress) { cSize = 0; goto out; }
     }
 
+    if (zc->seqCollector.collectSequences) {
+        ZSTD_copyBlockSequences(zc);
+        return 0;
+    }
+
     /* encode sequences and literals */
     cSize = ZSTD_compressSequences(&zc->seqStore,
             &zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
             &zc->appliedParams,
             dst, dstCapacity,
             srcSize,
             zc->entropyWorkspace, HUF_WORKSPACE_SIZE /* statically allocated in resetCCtx */,
             zc->bmi2);
 
+    if (frame &&
+        /* We don't want to emit our first block as a RLE even if it qualifies because
+         * doing so will cause the decoder (cli only) to throw a "should consume all input error."
+         * This is only an issue for zstd <= v1.4.3
+         */
+        !zc->isFirstBlock &&
+        cSize < rleMaxLength &&
+        ZSTD_isRLE(ip, srcSize))
+    {
+        cSize = 1;
+        op[0] = ip[0];
+    }
+
 out:
-    if (!ZSTD_isError(cSize) && cSize != 0) {
+    if (!ZSTD_isError(cSize) && cSize > 1) {
         /* confirm repcodes and entropy tables when emitting a compressed block */
         ZSTD_compressedBlockState_t* const tmp = zc->blockState.prevCBlock;
         zc->blockState.prevCBlock = zc->blockState.nextCBlock;
         zc->blockState.nextCBlock = tmp;
     }
     /* We check that dictionaries have offset codes available for the first
      * block. After the first block, the offcode table might not have large
      * enough codes to represent the offsets in the data.
      */
     if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
         zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
 
     return cSize;
 }
 
 
-static void ZSTD_overflowCorrectIfNeeded(ZSTD_matchState_t* ms, ZSTD_CCtx_params const* params, void const* ip, void const* iend)
+static void ZSTD_overflowCorrectIfNeeded(ZSTD_matchState_t* ms,
+                                         ZSTD_cwksp* ws,
+                                         ZSTD_CCtx_params const* params,
+                                         void const* ip,
+                                         void const* iend)
 {
     if (ZSTD_window_needOverflowCorrection(ms->window, iend)) {
         U32 const maxDist = (U32)1 << params->cParams.windowLog;
         U32 const cycleLog = ZSTD_cycleLog(params->cParams.chainLog, params->cParams.strategy);
         U32 const correction = ZSTD_window_correctOverflow(&ms->window, cycleLog, maxDist, ip);
         ZSTD_STATIC_ASSERT(ZSTD_CHAINLOG_MAX <= 30);
         ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX_32 <= 30);
         ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX <= 31);
+        ZSTD_cwksp_mark_tables_dirty(ws);
         ZSTD_reduceIndex(ms, params, correction);
+        ZSTD_cwksp_mark_tables_clean(ws);
         if (ms->nextToUpdate < correction) ms->nextToUpdate = 0;
         else ms->nextToUpdate -= correction;
         /* invalidate dictionaries on overflow correction */
         ms->loadedDictEnd = 0;
         ms->dictMatchState = NULL;
     }
 }
 
-
 /*! ZSTD_compress_frameChunk() :
 *   Compress a chunk of data into one or multiple blocks.
 *   All blocks will be terminated, all input will be consumed.
 *   Function will issue an error if there is not enough `dstCapacity` to hold the compressed content.
 *   Frame is supposed already started (header already produced)
 *   @return : compressed size, or an error code
 */
 static size_t ZSTD_compress_frameChunk (ZSTD_CCtx* cctx,
                                      void* dst, size_t dstCapacity,
                                const void* src, size_t srcSize,
                                      U32 lastFrameChunk)
 {
     size_t blockSize = cctx->blockSize;
     size_t remaining = srcSize;
     const BYTE* ip = (const BYTE*)src;
     BYTE* const ostart = (BYTE*)dst;
     BYTE* op = ostart;
     U32 const maxDist = (U32)1 << cctx->appliedParams.cParams.windowLog;
     assert(cctx->appliedParams.cParams.windowLog <= ZSTD_WINDOWLOG_MAX);
 
     DEBUGLOG(5, "ZSTD_compress_frameChunk (blockSize=%u)", (unsigned)blockSize);
     if (cctx->appliedParams.fParams.checksumFlag && srcSize)
         XXH64_update(&cctx->xxhState, src, srcSize);
 
     while (remaining) {
         ZSTD_matchState_t* const ms = &cctx->blockState.matchState;
         U32 const lastBlock = lastFrameChunk & (blockSize >= remaining);
 
         RETURN_ERROR_IF(dstCapacity < ZSTD_blockHeaderSize + MIN_CBLOCK_SIZE,
                         dstSize_tooSmall,
                         "not enough space to store compressed block");
         if (remaining < blockSize) blockSize = remaining;
 
-        ZSTD_overflowCorrectIfNeeded(ms, &cctx->appliedParams, ip, ip + blockSize);
+        ZSTD_overflowCorrectIfNeeded(
+            ms, &cctx->workspace, &cctx->appliedParams, ip, ip + blockSize);
         ZSTD_checkDictValidity(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd, &ms->dictMatchState);
 
         /* Ensure hash/chain table insertion resumes no sooner than lowlimit */
         if (ms->nextToUpdate < ms->window.lowLimit) ms->nextToUpdate = ms->window.lowLimit;
 
         {   size_t cSize = ZSTD_compressBlock_internal(cctx,
                                 op+ZSTD_blockHeaderSize, dstCapacity-ZSTD_blockHeaderSize,
-                                ip, blockSize);
+                                ip, blockSize, 1 /* frame */);
             FORWARD_IF_ERROR(cSize);
-
             if (cSize == 0) {  /* block is not compressible */
                 cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
                 FORWARD_IF_ERROR(cSize);
             } else {
-                U32 const cBlockHeader24 = lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
-                MEM_writeLE24(op, cBlockHeader24);
+                const U32 cBlockHeader = cSize == 1 ?
+                    lastBlock + (((U32)bt_rle)<<1) + (U32)(blockSize << 3) :
+                    lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
+                MEM_writeLE24(op, cBlockHeader);
                 cSize += ZSTD_blockHeaderSize;
             }
 
             ip += blockSize;
             assert(remaining >= blockSize);
             remaining -= blockSize;
             op += cSize;
             assert(dstCapacity >= cSize);
             dstCapacity -= cSize;
+            cctx->isFirstBlock = 0;
             DEBUGLOG(5, "ZSTD_compress_frameChunk: adding a block of size %u",
                         (unsigned)cSize);
     }   }
 
     if (lastFrameChunk && (op>ostart)) cctx->stage = ZSTDcs_ending;
     return (size_t)(op-ostart);
 }
 
 
 static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
-                                    ZSTD_CCtx_params params, U64 pledgedSrcSize, U32 dictID)
+                                    const ZSTD_CCtx_params* params, U64 pledgedSrcSize, U32 dictID)
 {   BYTE* const op = (BYTE*)dst;
     U32   const dictIDSizeCodeLength = (dictID>0) + (dictID>=256) + (dictID>=65536);   /* 0-3 */
-    U32   const dictIDSizeCode = params.fParams.noDictIDFlag ? 0 : dictIDSizeCodeLength;   /* 0-3 */
-    U32   const checksumFlag = params.fParams.checksumFlag>0;
-    U32   const windowSize = (U32)1 << params.cParams.windowLog;
-    U32   const singleSegment = params.fParams.contentSizeFlag && (windowSize >= pledgedSrcSize);
-    BYTE  const windowLogByte = (BYTE)((params.cParams.windowLog - ZSTD_WINDOWLOG_ABSOLUTEMIN) << 3);
-    U32   const fcsCode = params.fParams.contentSizeFlag ?
+    U32   const dictIDSizeCode = params->fParams.noDictIDFlag ? 0 : dictIDSizeCodeLength;   /* 0-3 */
+    U32   const checksumFlag = params->fParams.checksumFlag>0;
+    U32   const windowSize = (U32)1 << params->cParams.windowLog;
+    U32   const singleSegment = params->fParams.contentSizeFlag && (windowSize >= pledgedSrcSize);
+    BYTE  const windowLogByte = (BYTE)((params->cParams.windowLog - ZSTD_WINDOWLOG_ABSOLUTEMIN) << 3);
+    U32   const fcsCode = params->fParams.contentSizeFlag ?
                      (pledgedSrcSize>=256) + (pledgedSrcSize>=65536+256) + (pledgedSrcSize>=0xFFFFFFFFU) : 0;  /* 0-3 */
     BYTE  const frameHeaderDescriptionByte = (BYTE)(dictIDSizeCode + (checksumFlag<<2) + (singleSegment<<5) + (fcsCode<<6) );
     size_t pos=0;
 
-    assert(!(params.fParams.contentSizeFlag && pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN));
+    assert(!(params->fParams.contentSizeFlag && pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN));
     RETURN_ERROR_IF(dstCapacity < ZSTD_FRAMEHEADERSIZE_MAX, dstSize_tooSmall);
     DEBUGLOG(4, "ZSTD_writeFrameHeader : dictIDFlag : %u ; dictID : %u ; dictIDSizeCode : %u",
-                !params.fParams.noDictIDFlag, (unsigned)dictID, (unsigned)dictIDSizeCode);
+                !params->fParams.noDictIDFlag, (unsigned)dictID, (unsigned)dictIDSizeCode);
 
-    if (params.format == ZSTD_f_zstd1) {
+    if (params->format == ZSTD_f_zstd1) {
         MEM_writeLE32(dst, ZSTD_MAGICNUMBER);
         pos = 4;
     }
     op[pos++] = frameHeaderDescriptionByte;
     if (!singleSegment) op[pos++] = windowLogByte;
     switch(dictIDSizeCode)
     {
         default:  assert(0); /* impossible */
         case 0 : break;
         case 1 : op[pos] = (BYTE)(dictID); pos++; break;
         case 2 : MEM_writeLE16(op+pos, (U16)dictID); pos+=2; break;
         case 3 : MEM_writeLE32(op+pos, dictID); pos+=4; break;
     }
     switch(fcsCode)
     {
         default:  assert(0); /* impossible */
         case 0 : if (singleSegment) op[pos++] = (BYTE)(pledgedSrcSize); break;
         case 1 : MEM_writeLE16(op+pos, (U16)(pledgedSrcSize-256)); pos+=2; break;
         case 2 : MEM_writeLE32(op+pos, (U32)(pledgedSrcSize)); pos+=4; break;
         case 3 : MEM_writeLE64(op+pos, (U64)(pledgedSrcSize)); pos+=8; break;
     }
     return pos;
 }
 
 /* ZSTD_writeLastEmptyBlock() :
  * output an empty Block with end-of-frame mark to complete a frame
  * @return : size of data written into `dst` (== ZSTD_blockHeaderSize (defined in zstd_internal.h))
  *           or an error code if `dstCapacity` is too small (stage != ZSTDcs_init, stage_wrong);
     RETURN_ERROR_IF(cctx->appliedParams.ldmParams.enableLdm,
                     parameter_unsupported);
     cctx->externSeqStore.seq = seq;
     cctx->externSeqStore.size = nbSeq;
     cctx->externSeqStore.capacity = nbSeq;
     cctx->externSeqStore.pos = 0;
     return 0;
 }
 
 
 static size_t ZSTD_compressContinue_internal (ZSTD_CCtx* cctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize,
                                U32 frame, U32 lastFrameChunk)
 {
     ZSTD_matchState_t* const ms = &cctx->blockState.matchState;
     size_t fhSize = 0;
 
     DEBUGLOG(5, "ZSTD_compressContinue_internal, stage: %u, srcSize: %u",
                 cctx->stage, (unsigned)srcSize);
     RETURN_ERROR_IF(cctx->stage==ZSTDcs_created, stage_wrong,
                     "missing init (ZSTD_compressBegin)");
 
     if (frame && (cctx->stage==ZSTDcs_init)) {
-        fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, cctx->appliedParams,
+        fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, &cctx->appliedParams,
                                        cctx->pledgedSrcSizePlusOne-1, cctx->dictID);
         FORWARD_IF_ERROR(fhSize);
         assert(fhSize <= dstCapacity);
         dstCapacity -= fhSize;
         dst = (char*)dst + fhSize;
         cctx->stage = ZSTDcs_ongoing;
     }
 
     if (!srcSize) return fhSize;  /* do not generate an empty block if no input */
 
     if (!ZSTD_window_update(&ms->window, src, srcSize)) {
         ms->nextToUpdate = ms->window.dictLimit;
     }
     if (cctx->appliedParams.ldmParams.enableLdm) {
         ZSTD_window_update(&cctx->ldmState.window, src, srcSize);
     }
 
     if (!frame) {
         /* overflow check and correction for block mode */
-        ZSTD_overflowCorrectIfNeeded(ms, &cctx->appliedParams, src, (BYTE const*)src + srcSize);
+        ZSTD_overflowCorrectIfNeeded(
+            ms, &cctx->workspace, &cctx->appliedParams,
+            src, (BYTE const*)src + srcSize);
     }
 
     DEBUGLOG(5, "ZSTD_compressContinue_internal (blockSize=%u)", (unsigned)cctx->blockSize);
     {   size_t const cSize = frame ?
                              ZSTD_compress_frameChunk (cctx, dst, dstCapacity, src, srcSize, lastFrameChunk) :
-                             ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize);
+                             ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize, 0 /* frame */);
         FORWARD_IF_ERROR(cSize);
         cctx->consumedSrcSize += srcSize;
         cctx->producedCSize += (cSize + fhSize);
         assert(!(cctx->appliedParams.fParams.contentSizeFlag && cctx->pledgedSrcSizePlusOne == 0));
         if (cctx->pledgedSrcSizePlusOne != 0) {  /* control src size */
             ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN == (unsigned long long)-1);
             RETURN_ERROR_IF(
                 cctx->consumedSrcSize+1 > cctx->pledgedSrcSizePlusOne,
                 srcSize_wrong,
                 "error : pledgedSrcSize = %u, while realSrcSize >= %u",
                 (unsigned)cctx->pledgedSrcSizePlusOne-1,
                 (unsigned)cctx->consumedSrcSize);
         }
         return cSize + fhSize;
     }
 }
 
 size_t ZSTD_compressContinue (ZSTD_CCtx* cctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize)
 {
     DEBUGLOG(5, "ZSTD_compressContinue (srcSize=%u)", (unsigned)srcSize);
     return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 1 /* frame mode */, 0 /* last chunk */);
 }
 
 
 size_t ZSTD_getBlockSize(const ZSTD_CCtx* cctx)
 {
     ZSTD_compressionParameters const cParams = cctx->appliedParams.cParams;
     assert(!ZSTD_checkCParams(cParams));
     return MIN (ZSTD_BLOCKSIZE_MAX, (U32)1 << cParams.windowLog);
 }
 
 size_t ZSTD_compressBlock(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
-    size_t const blockSizeMax = ZSTD_getBlockSize(cctx);
-    RETURN_ERROR_IF(srcSize > blockSizeMax, srcSize_wrong);
+    DEBUGLOG(5, "ZSTD_compressBlock: srcSize = %u", (unsigned)srcSize);
+    { size_t const blockSizeMax = ZSTD_getBlockSize(cctx);
+      RETURN_ERROR_IF(srcSize > blockSizeMax, srcSize_wrong); }
 
     return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 0 /* frame mode */, 0 /* last chunk */);
 }
 
 /*! ZSTD_loadDictionaryContent() :
  *  @return : 0, or an error code
  */
 static size_t ZSTD_loadDictionaryContent(ZSTD_matchState_t* ms,
+                                         ZSTD_cwksp* ws,
                                          ZSTD_CCtx_params const* params,
                                          const void* src, size_t srcSize,
                                          ZSTD_dictTableLoadMethod_e dtlm)
 {
     const BYTE* ip = (const BYTE*) src;
     const BYTE* const iend = ip + srcSize;
 
     ZSTD_window_update(&ms->window, src, srcSize);
     ms->loadedDictEnd = params->forceWindow ? 0 : (U32)(iend - ms->window.base);
 
     /* Assert that we the ms params match the params we're being given */
     ZSTD_assertEqualCParams(params->cParams, ms->cParams);
 
     if (srcSize <= HASH_READ_SIZE) return 0;
 
     while (iend - ip > HASH_READ_SIZE) {
-        size_t const remaining = iend - ip;
+        size_t const remaining = (size_t)(iend - ip);
         size_t const chunk = MIN(remaining, ZSTD_CHUNKSIZE_MAX);
         const BYTE* const ichunk = ip + chunk;
 
-        ZSTD_overflowCorrectIfNeeded(ms, params, ip, ichunk);
+        ZSTD_overflowCorrectIfNeeded(ms, ws, params, ip, ichunk);
 
         switch(params->cParams.strategy)
         {
         case ZSTD_fast:
             ZSTD_fillHashTable(ms, ichunk, dtlm);
             break;
         case ZSTD_dfast:
             ZSTD_fillDoubleHashTable(ms, ichunk, dtlm);
             break;
 
         case ZSTD_greedy:
         case ZSTD_lazy:
         case ZSTD_lazy2:
             if (chunk >= HASH_READ_SIZE)
                 ZSTD_insertAndFindFirstIndex(ms, ichunk-HASH_READ_SIZE);
             break;
 
         case ZSTD_btlazy2:   /* we want the dictionary table fully sorted */
         case ZSTD_btopt:
         case ZSTD_btultra:
         case ZSTD_btultra2:
             if (chunk >= HASH_READ_SIZE)
                 ZSTD_updateTree(ms, ichunk-HASH_READ_SIZE, ichunk);
             break;
 
         default:
             assert(0);  /* not possible : not a valid strategy id */
         }
 
         ip = ichunk;
     }
 
     ms->nextToUpdate = (U32)(iend - ms->window.base);
     return 0;
 }
 
 
 /* Dictionaries that assign zero probability to symbols that show up causes problems
    when FSE encoding.  Refuse dictionaries that assign zero probability to symbols
    that we may encounter during compression.
    NOTE: This behavior is not standard and could be improved in the future. */
 static size_t ZSTD_checkDictNCount(short* normalizedCounter, unsigned dictMaxSymbolValue, unsigned maxSymbolValue) {
     U32 s;
     RETURN_ERROR_IF(dictMaxSymbolValue < maxSymbolValue, dictionary_corrupted);
     for (s = 0; s <= maxSymbolValue; ++s) {
         RETURN_ERROR_IF(normalizedCounter[s] == 0, dictionary_corrupted);
     }
     return 0;
 }
 
 
 /* Dictionary format :
  * See :
  * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
  */
 /*! ZSTD_loadZstdDictionary() :
  * @return : dictID, or an error code
  *  assumptions : magic number supposed already checked
- *                dictSize supposed > 8
+ *                dictSize supposed >= 8
  */
 static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
                                       ZSTD_matchState_t* ms,
+                                      ZSTD_cwksp* ws,
                                       ZSTD_CCtx_params const* params,
                                       const void* dict, size_t dictSize,
                                       ZSTD_dictTableLoadMethod_e dtlm,
                                       void* workspace)
 {
     const BYTE* dictPtr = (const BYTE*)dict;
     const BYTE* const dictEnd = dictPtr + dictSize;
     short offcodeNCount[MaxOff+1];
     unsigned offcodeMaxValue = MaxOff;
     size_t dictID;
 
     ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1< 8);
+    assert(dictSize >= 8);
     assert(MEM_readLE32(dictPtr) == ZSTD_MAGIC_DICTIONARY);
 
     dictPtr += 4;   /* skip magic number */
     dictID = params->fParams.noDictIDFlag ? 0 :  MEM_readLE32(dictPtr);
     dictPtr += 4;
 
     {   unsigned maxSymbolValue = 255;
         size_t const hufHeaderSize = HUF_readCTable((HUF_CElt*)bs->entropy.huf.CTable, &maxSymbolValue, dictPtr, dictEnd-dictPtr);
         RETURN_ERROR_IF(HUF_isError(hufHeaderSize), dictionary_corrupted);
         RETURN_ERROR_IF(maxSymbolValue < 255, dictionary_corrupted);
         dictPtr += hufHeaderSize;
     }
 
     {   unsigned offcodeLog;
         size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
         RETURN_ERROR_IF(FSE_isError(offcodeHeaderSize), dictionary_corrupted);
         RETURN_ERROR_IF(offcodeLog > OffFSELog, dictionary_corrupted);
         /* Defer checking offcodeMaxValue because we need to know the size of the dictionary content */
         /* fill all offset symbols to avoid garbage at end of table */
         RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
                 bs->entropy.fse.offcodeCTable,
                 offcodeNCount, MaxOff, offcodeLog,
                 workspace, HUF_WORKSPACE_SIZE)),
             dictionary_corrupted);
         dictPtr += offcodeHeaderSize;
     }
 
     {   short matchlengthNCount[MaxML+1];
         unsigned matchlengthMaxValue = MaxML, matchlengthLog;
         size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
         RETURN_ERROR_IF(FSE_isError(matchlengthHeaderSize), dictionary_corrupted);
         RETURN_ERROR_IF(matchlengthLog > MLFSELog, dictionary_corrupted);
         /* Every match length code must have non-zero probability */
         FORWARD_IF_ERROR( ZSTD_checkDictNCount(matchlengthNCount, matchlengthMaxValue, MaxML));
         RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
                 bs->entropy.fse.matchlengthCTable,
                 matchlengthNCount, matchlengthMaxValue, matchlengthLog,
                 workspace, HUF_WORKSPACE_SIZE)),
             dictionary_corrupted);
         dictPtr += matchlengthHeaderSize;
     }
 
     {   short litlengthNCount[MaxLL+1];
         unsigned litlengthMaxValue = MaxLL, litlengthLog;
         size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
         RETURN_ERROR_IF(FSE_isError(litlengthHeaderSize), dictionary_corrupted);
         RETURN_ERROR_IF(litlengthLog > LLFSELog, dictionary_corrupted);
         /* Every literal length code must have non-zero probability */
         FORWARD_IF_ERROR( ZSTD_checkDictNCount(litlengthNCount, litlengthMaxValue, MaxLL));
         RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
                 bs->entropy.fse.litlengthCTable,
                 litlengthNCount, litlengthMaxValue, litlengthLog,
                 workspace, HUF_WORKSPACE_SIZE)),
             dictionary_corrupted);
         dictPtr += litlengthHeaderSize;
     }
 
     RETURN_ERROR_IF(dictPtr+12 > dictEnd, dictionary_corrupted);
     bs->rep[0] = MEM_readLE32(dictPtr+0);
     bs->rep[1] = MEM_readLE32(dictPtr+4);
     bs->rep[2] = MEM_readLE32(dictPtr+8);
     dictPtr += 12;
 
     {   size_t const dictContentSize = (size_t)(dictEnd - dictPtr);
         U32 offcodeMax = MaxOff;
         if (dictContentSize <= ((U32)-1) - 128 KB) {
             U32 const maxOffset = (U32)dictContentSize + 128 KB; /* The maximum offset that must be supported */
             offcodeMax = ZSTD_highbit32(maxOffset); /* Calculate minimum offset code required to represent maxOffset */
         }
         /* All offset values <= dictContentSize + 128 KB must be representable */
         FORWARD_IF_ERROR(ZSTD_checkDictNCount(offcodeNCount, offcodeMaxValue, MIN(offcodeMax, MaxOff)));
         /* All repCodes must be <= dictContentSize and != 0*/
         {   U32 u;
             for (u=0; u<3; u++) {
                 RETURN_ERROR_IF(bs->rep[u] == 0, dictionary_corrupted);
                 RETURN_ERROR_IF(bs->rep[u] > dictContentSize, dictionary_corrupted);
         }   }
 
         bs->entropy.huf.repeatMode = HUF_repeat_valid;
         bs->entropy.fse.offcode_repeatMode = FSE_repeat_valid;
         bs->entropy.fse.matchlength_repeatMode = FSE_repeat_valid;
         bs->entropy.fse.litlength_repeatMode = FSE_repeat_valid;
-        FORWARD_IF_ERROR(ZSTD_loadDictionaryContent(ms, params, dictPtr, dictContentSize, dtlm));
+        FORWARD_IF_ERROR(ZSTD_loadDictionaryContent(
+            ms, ws, params, dictPtr, dictContentSize, dtlm));
         return dictID;
     }
 }
 
 /** ZSTD_compress_insertDictionary() :
 *   @return : dictID, or an error code */
 static size_t
 ZSTD_compress_insertDictionary(ZSTD_compressedBlockState_t* bs,
                                ZSTD_matchState_t* ms,
+                               ZSTD_cwksp* ws,
                          const ZSTD_CCtx_params* params,
                          const void* dict, size_t dictSize,
                                ZSTD_dictContentType_e dictContentType,
                                ZSTD_dictTableLoadMethod_e dtlm,
                                void* workspace)
 {
     DEBUGLOG(4, "ZSTD_compress_insertDictionary (dictSize=%u)", (U32)dictSize);
-    if ((dict==NULL) || (dictSize<=8)) return 0;
+    if ((dict==NULL) || (dictSize<8)) {
+        RETURN_ERROR_IF(dictContentType == ZSTD_dct_fullDict, dictionary_wrong);
+        return 0;
+    }
 
     ZSTD_reset_compressedBlockState(bs);
 
     /* dict restricted modes */
     if (dictContentType == ZSTD_dct_rawContent)
-        return ZSTD_loadDictionaryContent(ms, params, dict, dictSize, dtlm);
+        return ZSTD_loadDictionaryContent(ms, ws, params, dict, dictSize, dtlm);
 
     if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) {
         if (dictContentType == ZSTD_dct_auto) {
             DEBUGLOG(4, "raw content dictionary detected");
-            return ZSTD_loadDictionaryContent(ms, params, dict, dictSize, dtlm);
+            return ZSTD_loadDictionaryContent(
+                ms, ws, params, dict, dictSize, dtlm);
         }
         RETURN_ERROR_IF(dictContentType == ZSTD_dct_fullDict, dictionary_wrong);
         assert(0);   /* impossible */
     }
 
     /* dict as full zstd dictionary */
-    return ZSTD_loadZstdDictionary(bs, ms, params, dict, dictSize, dtlm, workspace);
+    return ZSTD_loadZstdDictionary(
+        bs, ms, ws, params, dict, dictSize, dtlm, workspace);
 }
 
+#define ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF (128 KB)
+#define ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER (6)
+
 /*! ZSTD_compressBegin_internal() :
  * @return : 0, or an error code */
 static size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
                                     const void* dict, size_t dictSize,
                                     ZSTD_dictContentType_e dictContentType,
                                     ZSTD_dictTableLoadMethod_e dtlm,
                                     const ZSTD_CDict* cdict,
-                                    ZSTD_CCtx_params params, U64 pledgedSrcSize,
+                                    const ZSTD_CCtx_params* params, U64 pledgedSrcSize,
                                     ZSTD_buffered_policy_e zbuff)
 {
-    DEBUGLOG(4, "ZSTD_compressBegin_internal: wlog=%u", params.cParams.windowLog);
+    DEBUGLOG(4, "ZSTD_compressBegin_internal: wlog=%u", params->cParams.windowLog);
     /* params are supposed to be fully validated at this point */
-    assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
+    assert(!ZSTD_isError(ZSTD_checkCParams(params->cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
-
-    if (cdict && cdict->dictContentSize>0) {
+    if ( (cdict)
+      && (cdict->dictContentSize > 0)
+      && ( pledgedSrcSize < ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF
+        || pledgedSrcSize < cdict->dictContentSize * ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER
+        || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
+        || cdict->compressionLevel == 0)
+      && (params->attachDictPref != ZSTD_dictForceLoad) ) {
         return ZSTD_resetCCtx_usingCDict(cctx, cdict, params, pledgedSrcSize, zbuff);
     }
 
-    FORWARD_IF_ERROR( ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
-                                     ZSTDcrp_continue, zbuff) );
-    {   size_t const dictID = ZSTD_compress_insertDictionary(
-                cctx->blockState.prevCBlock, &cctx->blockState.matchState,
-                ¶ms, dict, dictSize, dictContentType, dtlm, cctx->entropyWorkspace);
+    FORWARD_IF_ERROR( ZSTD_resetCCtx_internal(cctx, *params, pledgedSrcSize,
+                                     ZSTDcrp_makeClean, zbuff) );
+    {   size_t const dictID = cdict ?
+                ZSTD_compress_insertDictionary(
+                        cctx->blockState.prevCBlock, &cctx->blockState.matchState,
+                        &cctx->workspace, params, cdict->dictContent, cdict->dictContentSize,
+                        dictContentType, dtlm, cctx->entropyWorkspace)
+              : ZSTD_compress_insertDictionary(
+                        cctx->blockState.prevCBlock, &cctx->blockState.matchState,
+                        &cctx->workspace, params, dict, dictSize,
+                        dictContentType, dtlm, cctx->entropyWorkspace);
         FORWARD_IF_ERROR(dictID);
         assert(dictID <= UINT_MAX);
         cctx->dictID = (U32)dictID;
     }
     return 0;
 }
 
 size_t ZSTD_compressBegin_advanced_internal(ZSTD_CCtx* cctx,
                                     const void* dict, size_t dictSize,
                                     ZSTD_dictContentType_e dictContentType,
                                     ZSTD_dictTableLoadMethod_e dtlm,
                                     const ZSTD_CDict* cdict,
-                                    ZSTD_CCtx_params params,
+                                    const ZSTD_CCtx_params* params,
                                     unsigned long long pledgedSrcSize)
 {
-    DEBUGLOG(4, "ZSTD_compressBegin_advanced_internal: wlog=%u", params.cParams.windowLog);
+    DEBUGLOG(4, "ZSTD_compressBegin_advanced_internal: wlog=%u", params->cParams.windowLog);
     /* compression parameters verification and optimization */
-    FORWARD_IF_ERROR( ZSTD_checkCParams(params.cParams) );
+    FORWARD_IF_ERROR( ZSTD_checkCParams(params->cParams) );
     return ZSTD_compressBegin_internal(cctx,
                                        dict, dictSize, dictContentType, dtlm,
                                        cdict,
                                        params, pledgedSrcSize,
                                        ZSTDb_not_buffered);
 }
 
 /*! ZSTD_compressBegin_advanced() :
 *   @return : 0, or an error code */
 size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx,
                              const void* dict, size_t dictSize,
                                    ZSTD_parameters params, unsigned long long pledgedSrcSize)
 {
     ZSTD_CCtx_params const cctxParams =
-            ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
+            ZSTD_assignParamsToCCtxParams(&cctx->requestedParams, params);
     return ZSTD_compressBegin_advanced_internal(cctx,
                                             dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast,
                                             NULL /*cdict*/,
-                                            cctxParams, pledgedSrcSize);
+                                            &cctxParams, pledgedSrcSize);
 }
 
 size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_parameters const params = ZSTD_getParams(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, dictSize);
     ZSTD_CCtx_params const cctxParams =
-            ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
+            ZSTD_assignParamsToCCtxParams(&cctx->requestedParams, params);
     DEBUGLOG(4, "ZSTD_compressBegin_usingDict (dictSize=%u)", (unsigned)dictSize);
     return ZSTD_compressBegin_internal(cctx, dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast, NULL,
-                                       cctxParams, ZSTD_CONTENTSIZE_UNKNOWN, ZSTDb_not_buffered);
+                                       &cctxParams, ZSTD_CONTENTSIZE_UNKNOWN, ZSTDb_not_buffered);
 }
 
 size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel)
 {
     return ZSTD_compressBegin_usingDict(cctx, NULL, 0, compressionLevel);
 }
 
 
 /*! ZSTD_writeEpilogue() :
 *   Ends a frame.
 *   @return : nb of bytes written into dst (or an error code) */
 static size_t ZSTD_writeEpilogue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity)
 {
     BYTE* const ostart = (BYTE*)dst;
     BYTE* op = ostart;
     size_t fhSize = 0;
 
     DEBUGLOG(4, "ZSTD_writeEpilogue");
     RETURN_ERROR_IF(cctx->stage == ZSTDcs_created, stage_wrong, "init missing");
 
     /* special case : empty frame */
     if (cctx->stage == ZSTDcs_init) {
-        fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, cctx->appliedParams, 0, 0);
+        fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, &cctx->appliedParams, 0, 0);
         FORWARD_IF_ERROR(fhSize);
         dstCapacity -= fhSize;
         op += fhSize;
         cctx->stage = ZSTDcs_ongoing;
     }
 
     if (cctx->stage != ZSTDcs_ending) {
         /* write one last empty block, make it the "last" block */
         U32 const cBlockHeader24 = 1 /* last block */ + (((U32)bt_raw)<<1) + 0;
         RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall);
         MEM_writeLE32(op, cBlockHeader24);
         op += ZSTD_blockHeaderSize;
         dstCapacity -= ZSTD_blockHeaderSize;
     }
 
     if (cctx->appliedParams.fParams.checksumFlag) {
         U32 const checksum = (U32) XXH64_digest(&cctx->xxhState);
         RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall);
         DEBUGLOG(4, "ZSTD_writeEpilogue: write checksum : %08X", (unsigned)checksum);
         MEM_writeLE32(op, checksum);
         op += 4;
     }
 
     cctx->stage = ZSTDcs_created;  /* return to "created but no init" status */
     return op-ostart;
 }
 
 size_t ZSTD_compressEnd (ZSTD_CCtx* cctx,
                          void* dst, size_t dstCapacity,
                    const void* src, size_t srcSize)
 {
     size_t endResult;
     size_t const cSize = ZSTD_compressContinue_internal(cctx,
                                 dst, dstCapacity, src, srcSize,
                                 1 /* frame mode */, 1 /* last chunk */);
     FORWARD_IF_ERROR(cSize);
     endResult = ZSTD_writeEpilogue(cctx, (char*)dst + cSize, dstCapacity-cSize);
     FORWARD_IF_ERROR(endResult);
     assert(!(cctx->appliedParams.fParams.contentSizeFlag && cctx->pledgedSrcSizePlusOne == 0));
     if (cctx->pledgedSrcSizePlusOne != 0) {  /* control src size */
         ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN == (unsigned long long)-1);
         DEBUGLOG(4, "end of frame : controlling src size");
         RETURN_ERROR_IF(
             cctx->pledgedSrcSizePlusOne != cctx->consumedSrcSize+1,
             srcSize_wrong,
              "error : pledgedSrcSize = %u, while realSrcSize = %u",
             (unsigned)cctx->pledgedSrcSizePlusOne-1,
             (unsigned)cctx->consumedSrcSize);
     }
     return cSize + endResult;
 }
 
 
 static size_t ZSTD_compress_internal (ZSTD_CCtx* cctx,
                                       void* dst, size_t dstCapacity,
                                 const void* src, size_t srcSize,
                                 const void* dict,size_t dictSize,
                                       ZSTD_parameters params)
 {
     ZSTD_CCtx_params const cctxParams =
-            ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
+            ZSTD_assignParamsToCCtxParams(&cctx->requestedParams, params);
     DEBUGLOG(4, "ZSTD_compress_internal");
     return ZSTD_compress_advanced_internal(cctx,
                                            dst, dstCapacity,
                                            src, srcSize,
                                            dict, dictSize,
-                                           cctxParams);
+                                           &cctxParams);
 }
 
 size_t ZSTD_compress_advanced (ZSTD_CCtx* cctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                          const void* dict,size_t dictSize,
                                ZSTD_parameters params)
 {
     DEBUGLOG(4, "ZSTD_compress_advanced");
     FORWARD_IF_ERROR(ZSTD_checkCParams(params.cParams));
     return ZSTD_compress_internal(cctx,
                                   dst, dstCapacity,
                                   src, srcSize,
                                   dict, dictSize,
                                   params);
 }
 
 /* Internal */
 size_t ZSTD_compress_advanced_internal(
         ZSTD_CCtx* cctx,
         void* dst, size_t dstCapacity,
         const void* src, size_t srcSize,
         const void* dict,size_t dictSize,
-        ZSTD_CCtx_params params)
+        const ZSTD_CCtx_params* params)
 {
     DEBUGLOG(4, "ZSTD_compress_advanced_internal (srcSize:%u)", (unsigned)srcSize);
     FORWARD_IF_ERROR( ZSTD_compressBegin_internal(cctx,
                          dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast, NULL,
                          params, srcSize, ZSTDb_not_buffered) );
     return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
 }
 
 size_t ZSTD_compress_usingDict(ZSTD_CCtx* cctx,
                                void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize,
                          const void* dict, size_t dictSize,
                                int compressionLevel)
 {
     ZSTD_parameters const params = ZSTD_getParams(compressionLevel, srcSize + (!srcSize), dict ? dictSize : 0);
-    ZSTD_CCtx_params cctxParams = ZSTD_assignParamsToCCtxParams(cctx->requestedParams, params);
+    ZSTD_CCtx_params cctxParams = ZSTD_assignParamsToCCtxParams(&cctx->requestedParams, params);
     assert(params.fParams.contentSizeFlag == 1);
-    return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, dict, dictSize, cctxParams);
+    return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, dict, dictSize, &cctxParams);
 }
 
 size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx,
                          void* dst, size_t dstCapacity,
                    const void* src, size_t srcSize,
                          int compressionLevel)
 {
     DEBUGLOG(4, "ZSTD_compressCCtx (srcSize=%u)", (unsigned)srcSize);
     assert(cctx != NULL);
     return ZSTD_compress_usingDict(cctx, dst, dstCapacity, src, srcSize, NULL, 0, compressionLevel);
 }
 
 size_t ZSTD_compress(void* dst, size_t dstCapacity,
                const void* src, size_t srcSize,
                      int compressionLevel)
 {
     size_t result;
     ZSTD_CCtx ctxBody;
     ZSTD_initCCtx(&ctxBody, ZSTD_defaultCMem);
     result = ZSTD_compressCCtx(&ctxBody, dst, dstCapacity, src, srcSize, compressionLevel);
     ZSTD_freeCCtxContent(&ctxBody);   /* can't free ctxBody itself, as it's on stack; free only heap content */
     return result;
 }
 
 
 /* =====  Dictionary API  ===== */
 
 /*! ZSTD_estimateCDictSize_advanced() :
  *  Estimate amount of memory that will be needed to create a dictionary with following arguments */
 size_t ZSTD_estimateCDictSize_advanced(
         size_t dictSize, ZSTD_compressionParameters cParams,
         ZSTD_dictLoadMethod_e dictLoadMethod)
 {
     DEBUGLOG(5, "sizeof(ZSTD_CDict) : %u", (unsigned)sizeof(ZSTD_CDict));
-    return sizeof(ZSTD_CDict) + HUF_WORKSPACE_SIZE + ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0)
-           + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
+    return ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict))
+         + ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE)
+         + ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0)
+         + (dictLoadMethod == ZSTD_dlm_byRef ? 0
+            : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void *))));
 }
 
 size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel)
 {
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
     return ZSTD_estimateCDictSize_advanced(dictSize, cParams, ZSTD_dlm_byCopy);
 }
 
 size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict)
 {
     if (cdict==NULL) return 0;   /* support sizeof on NULL */
     DEBUGLOG(5, "sizeof(*cdict) : %u", (unsigned)sizeof(*cdict));
-    return cdict->workspaceSize + (cdict->dictBuffer ? cdict->dictContentSize : 0) + sizeof(*cdict);
+    /* cdict may be in the workspace */
+    return (cdict->workspace.workspace == cdict ? 0 : sizeof(*cdict))
+        + ZSTD_cwksp_sizeof(&cdict->workspace);
 }
 
 static size_t ZSTD_initCDict_internal(
                     ZSTD_CDict* cdict,
               const void* dictBuffer, size_t dictSize,
                     ZSTD_dictLoadMethod_e dictLoadMethod,
                     ZSTD_dictContentType_e dictContentType,
                     ZSTD_compressionParameters cParams)
 {
     DEBUGLOG(3, "ZSTD_initCDict_internal (dictContentType:%u)", (unsigned)dictContentType);
     assert(!ZSTD_checkCParams(cParams));
     cdict->matchState.cParams = cParams;
     if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dictBuffer) || (!dictSize)) {
-        cdict->dictBuffer = NULL;
         cdict->dictContent = dictBuffer;
     } else {
-        void* const internalBuffer = ZSTD_malloc(dictSize, cdict->customMem);
-        cdict->dictBuffer = internalBuffer;
-        cdict->dictContent = internalBuffer;
+         void *internalBuffer = ZSTD_cwksp_reserve_object(&cdict->workspace, ZSTD_cwksp_align(dictSize, sizeof(void*)));
         RETURN_ERROR_IF(!internalBuffer, memory_allocation);
+        cdict->dictContent = internalBuffer;
         memcpy(internalBuffer, dictBuffer, dictSize);
     }
     cdict->dictContentSize = dictSize;
 
+    cdict->entropyWorkspace = (U32*)ZSTD_cwksp_reserve_object(&cdict->workspace, HUF_WORKSPACE_SIZE);
+
+
     /* Reset the state to no dictionary */
     ZSTD_reset_compressedBlockState(&cdict->cBlockState);
-    {   void* const end = ZSTD_reset_matchState(&cdict->matchState,
-                            (U32*)cdict->workspace + HUF_WORKSPACE_SIZE_U32,
-                            &cParams,
-                             ZSTDcrp_continue, ZSTD_resetTarget_CDict);
-        assert(end == (char*)cdict->workspace + cdict->workspaceSize);
-        (void)end;
-    }
+    FORWARD_IF_ERROR(ZSTD_reset_matchState(
+        &cdict->matchState,
+        &cdict->workspace,
+        &cParams,
+        ZSTDcrp_makeClean,
+        ZSTDirp_reset,
+        ZSTD_resetTarget_CDict));
     /* (Maybe) load the dictionary
-     * Skips loading the dictionary if it is <= 8 bytes.
+     * Skips loading the dictionary if it is < 8 bytes.
      */
     {   ZSTD_CCtx_params params;
         memset(¶ms, 0, sizeof(params));
         params.compressionLevel = ZSTD_CLEVEL_DEFAULT;
         params.fParams.contentSizeFlag = 1;
         params.cParams = cParams;
         {   size_t const dictID = ZSTD_compress_insertDictionary(
-                    &cdict->cBlockState, &cdict->matchState, ¶ms,
-                    cdict->dictContent, cdict->dictContentSize,
-                    dictContentType, ZSTD_dtlm_full, cdict->workspace);
+                    &cdict->cBlockState, &cdict->matchState, &cdict->workspace,
+                    ¶ms, cdict->dictContent, cdict->dictContentSize,
+                    dictContentType, ZSTD_dtlm_full, cdict->entropyWorkspace);
             FORWARD_IF_ERROR(dictID);
             assert(dictID <= (size_t)(U32)-1);
             cdict->dictID = (U32)dictID;
         }
     }
 
     return 0;
 }
 
 ZSTD_CDict* ZSTD_createCDict_advanced(const void* dictBuffer, size_t dictSize,
                                       ZSTD_dictLoadMethod_e dictLoadMethod,
                                       ZSTD_dictContentType_e dictContentType,
                                       ZSTD_compressionParameters cParams, ZSTD_customMem customMem)
 {
     DEBUGLOG(3, "ZSTD_createCDict_advanced, mode %u", (unsigned)dictContentType);
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
 
-    {   ZSTD_CDict* const cdict = (ZSTD_CDict*)ZSTD_malloc(sizeof(ZSTD_CDict), customMem);
-        size_t const workspaceSize = HUF_WORKSPACE_SIZE + ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0);
+    {   size_t const workspaceSize =
+            ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict)) +
+            ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE) +
+            ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0) +
+            (dictLoadMethod == ZSTD_dlm_byRef ? 0
+             : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void*))));
         void* const workspace = ZSTD_malloc(workspaceSize, customMem);
+        ZSTD_cwksp ws;
+        ZSTD_CDict* cdict;
 
-        if (!cdict || !workspace) {
-            ZSTD_free(cdict, customMem);
+        if (!workspace) {
             ZSTD_free(workspace, customMem);
             return NULL;
         }
+
+        ZSTD_cwksp_init(&ws, workspace, workspaceSize);
+
+        cdict = (ZSTD_CDict*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CDict));
+        assert(cdict != NULL);
+        ZSTD_cwksp_move(&cdict->workspace, &ws);
         cdict->customMem = customMem;
-        cdict->workspace = workspace;
-        cdict->workspaceSize = workspaceSize;
+        cdict->compressionLevel = 0; /* signals advanced API usage */
+
         if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
                                         dictBuffer, dictSize,
                                         dictLoadMethod, dictContentType,
                                         cParams) )) {
             ZSTD_freeCDict(cdict);
             return NULL;
         }
 
         return cdict;
     }
 }
 
 ZSTD_CDict* ZSTD_createCDict(const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_compressionParameters cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
-    return ZSTD_createCDict_advanced(dict, dictSize,
-                                     ZSTD_dlm_byCopy, ZSTD_dct_auto,
-                                     cParams, ZSTD_defaultCMem);
+    ZSTD_CDict* cdict = ZSTD_createCDict_advanced(dict, dictSize,
+                                                  ZSTD_dlm_byCopy, ZSTD_dct_auto,
+                                                  cParams, ZSTD_defaultCMem);
+    if (cdict)
+        cdict->compressionLevel = compressionLevel == 0 ? ZSTD_CLEVEL_DEFAULT : compressionLevel;
+    return cdict;
 }
 
 ZSTD_CDict* ZSTD_createCDict_byReference(const void* dict, size_t dictSize, int compressionLevel)
 {
     ZSTD_compressionParameters cParams = ZSTD_getCParams(compressionLevel, 0, dictSize);
     return ZSTD_createCDict_advanced(dict, dictSize,
                                      ZSTD_dlm_byRef, ZSTD_dct_auto,
                                      cParams, ZSTD_defaultCMem);
 }
 
 size_t ZSTD_freeCDict(ZSTD_CDict* cdict)
 {
     if (cdict==NULL) return 0;   /* support free on NULL */
     {   ZSTD_customMem const cMem = cdict->customMem;
-        ZSTD_free(cdict->workspace, cMem);
-        ZSTD_free(cdict->dictBuffer, cMem);
-        ZSTD_free(cdict, cMem);
+        int cdictInWorkspace = ZSTD_cwksp_owns_buffer(&cdict->workspace, cdict);
+        ZSTD_cwksp_free(&cdict->workspace, cMem);
+        if (!cdictInWorkspace) {
+            ZSTD_free(cdict, cMem);
+        }
         return 0;
     }
 }
 
 /*! ZSTD_initStaticCDict_advanced() :
  *  Generate a digested dictionary in provided memory area.
  *  workspace: The memory area to emplace the dictionary into.
  *             Provided pointer must 8-bytes aligned.
  *             It must outlive dictionary usage.
  *  workspaceSize: Use ZSTD_estimateCDictSize()
  *                 to determine how large workspace must be.
  *  cParams : use ZSTD_getCParams() to transform a compression level
  *            into its relevants cParams.
  * @return : pointer to ZSTD_CDict*, or NULL if error (size too small)
  *  Note : there is no corresponding "free" function.
  *         Since workspace was allocated externally, it must be freed externally.
  */
 const ZSTD_CDict* ZSTD_initStaticCDict(
                                  void* workspace, size_t workspaceSize,
                            const void* dict, size_t dictSize,
                                  ZSTD_dictLoadMethod_e dictLoadMethod,
                                  ZSTD_dictContentType_e dictContentType,
                                  ZSTD_compressionParameters cParams)
 {
     size_t const matchStateSize = ZSTD_sizeof_matchState(&cParams, /* forCCtx */ 0);
-    size_t const neededSize = sizeof(ZSTD_CDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize)
-                            + HUF_WORKSPACE_SIZE + matchStateSize;
-    ZSTD_CDict* const cdict = (ZSTD_CDict*) workspace;
-    void* ptr;
+    size_t const neededSize = ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict))
+                            + (dictLoadMethod == ZSTD_dlm_byRef ? 0
+                               : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void*))))
+                            + ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE)
+                            + matchStateSize;
+    ZSTD_CDict* cdict;
+
     if ((size_t)workspace & 7) return NULL;  /* 8-aligned */
+
+    {
+        ZSTD_cwksp ws;
+        ZSTD_cwksp_init(&ws, workspace, workspaceSize);
+        cdict = (ZSTD_CDict*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CDict));
+        if (cdict == NULL) return NULL;
+        ZSTD_cwksp_move(&cdict->workspace, &ws);
+    }
+
     DEBUGLOG(4, "(workspaceSize < neededSize) : (%u < %u) => %u",
         (unsigned)workspaceSize, (unsigned)neededSize, (unsigned)(workspaceSize < neededSize));
     if (workspaceSize < neededSize) return NULL;
 
-    if (dictLoadMethod == ZSTD_dlm_byCopy) {
-        memcpy(cdict+1, dict, dictSize);
-        dict = cdict+1;
-        ptr = (char*)workspace + sizeof(ZSTD_CDict) + dictSize;
-    } else {
-        ptr = cdict+1;
-    }
-    cdict->workspace = ptr;
-    cdict->workspaceSize = HUF_WORKSPACE_SIZE + matchStateSize;
-
     if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
                                               dict, dictSize,
-                                              ZSTD_dlm_byRef, dictContentType,
+                                              dictLoadMethod, dictContentType,
                                               cParams) ))
         return NULL;
 
     return cdict;
 }
 
 ZSTD_compressionParameters ZSTD_getCParamsFromCDict(const ZSTD_CDict* cdict)
 {
     assert(cdict != NULL);
     return cdict->matchState.cParams;
 }
 
 /* ZSTD_compressBegin_usingCDict_advanced() :
  * cdict must be != NULL */
 size_t ZSTD_compressBegin_usingCDict_advanced(
     ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict,
     ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_compressBegin_usingCDict_advanced");
     RETURN_ERROR_IF(cdict==NULL, dictionary_wrong);
     {   ZSTD_CCtx_params params = cctx->requestedParams;
-        params.cParams = ZSTD_getCParamsFromCDict(cdict);
+        params.cParams = ( pledgedSrcSize < ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF
+                        || pledgedSrcSize < cdict->dictContentSize * ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER
+                        || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
+                        || cdict->compressionLevel == 0 )
+                      && (params.attachDictPref != ZSTD_dictForceLoad) ?
+                ZSTD_getCParamsFromCDict(cdict)
+              : ZSTD_getCParams(cdict->compressionLevel,
+                                pledgedSrcSize,
+                                cdict->dictContentSize);
         /* Increase window log to fit the entire dictionary and source if the
          * source size is known. Limit the increase to 19, which is the
          * window log for compression level 1 with the largest source size.
          */
         if (pledgedSrcSize != ZSTD_CONTENTSIZE_UNKNOWN) {
             U32 const limitedSrcSize = (U32)MIN(pledgedSrcSize, 1U << 19);
             U32 const limitedSrcLog = limitedSrcSize > 1 ? ZSTD_highbit32(limitedSrcSize - 1) + 1 : 1;
             params.cParams.windowLog = MAX(params.cParams.windowLog, limitedSrcLog);
         }
         params.fParams = fParams;
         return ZSTD_compressBegin_internal(cctx,
                                            NULL, 0, ZSTD_dct_auto, ZSTD_dtlm_fast,
                                            cdict,
-                                           params, pledgedSrcSize,
+                                           ¶ms, pledgedSrcSize,
                                            ZSTDb_not_buffered);
     }
 }
 
 /* ZSTD_compressBegin_usingCDict() :
  * pledgedSrcSize=0 means "unknown"
  * if pledgedSrcSize>0, it will enable contentSizeFlag */
 size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
 {
     ZSTD_frameParameters const fParams = { 0 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
     DEBUGLOG(4, "ZSTD_compressBegin_usingCDict : dictIDFlag == %u", !fParams.noDictIDFlag);
     return ZSTD_compressBegin_usingCDict_advanced(cctx, cdict, fParams, ZSTD_CONTENTSIZE_UNKNOWN);
 }
 
 size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
                                 void* dst, size_t dstCapacity,
                                 const void* src, size_t srcSize,
                                 const ZSTD_CDict* cdict, ZSTD_frameParameters fParams)
 {
     FORWARD_IF_ERROR(ZSTD_compressBegin_usingCDict_advanced(cctx, cdict, fParams, srcSize));   /* will check if cdict != NULL */
     return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
 }
 
 /*! ZSTD_compress_usingCDict() :
  *  Compression using a digested Dictionary.
  *  Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
  *  Note that compression parameters are decided at CDict creation time
  *  while frame parameters are hardcoded */
 size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
                                 void* dst, size_t dstCapacity,
                                 const void* src, size_t srcSize,
                                 const ZSTD_CDict* cdict)
 {
     ZSTD_frameParameters const fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
     return ZSTD_compress_usingCDict_advanced(cctx, dst, dstCapacity, src, srcSize, cdict, fParams);
 }
 
 
 
 /* ******************************************************************
 *  Streaming
 ********************************************************************/
 
 ZSTD_CStream* ZSTD_createCStream(void)
 {
     DEBUGLOG(3, "ZSTD_createCStream");
     return ZSTD_createCStream_advanced(ZSTD_defaultCMem);
 }
 
 ZSTD_CStream* ZSTD_initStaticCStream(void *workspace, size_t workspaceSize)
 {
     return ZSTD_initStaticCCtx(workspace, workspaceSize);
 }
 
 ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem)
 {   /* CStream and CCtx are now same object */
     return ZSTD_createCCtx_advanced(customMem);
 }
 
 size_t ZSTD_freeCStream(ZSTD_CStream* zcs)
 {
     return ZSTD_freeCCtx(zcs);   /* same object */
 }
 
 
 
 /*======   Initialization   ======*/
 
 size_t ZSTD_CStreamInSize(void)  { return ZSTD_BLOCKSIZE_MAX; }
 
 size_t ZSTD_CStreamOutSize(void)
 {
     return ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + 4 /* 32-bits hash */ ;
 }
 
 static size_t ZSTD_resetCStream_internal(ZSTD_CStream* cctx,
                     const void* const dict, size_t const dictSize, ZSTD_dictContentType_e const dictContentType,
                     const ZSTD_CDict* const cdict,
                     ZSTD_CCtx_params params, unsigned long long const pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_resetCStream_internal");
     /* Finalize the compression parameters */
     params.cParams = ZSTD_getCParamsFromCCtxParams(¶ms, pledgedSrcSize, dictSize);
     /* params are supposed to be fully validated at this point */
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
 
     FORWARD_IF_ERROR( ZSTD_compressBegin_internal(cctx,
                                          dict, dictSize, dictContentType, ZSTD_dtlm_fast,
                                          cdict,
-                                         params, pledgedSrcSize,
+                                         ¶ms, pledgedSrcSize,
                                          ZSTDb_buffered) );
 
     cctx->inToCompress = 0;
     cctx->inBuffPos = 0;
     cctx->inBuffTarget = cctx->blockSize
                       + (cctx->blockSize == pledgedSrcSize);   /* for small input: avoid automatic flush on reaching end of block, since it would require to add a 3-bytes null block to end frame */
     cctx->outBuffContentSize = cctx->outBuffFlushedSize = 0;
     cctx->streamStage = zcss_load;
     cctx->frameEnded = 0;
     return 0;   /* ready to go */
 }
 
 /* ZSTD_resetCStream():
  * pledgedSrcSize == 0 means "unknown" */
 size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pss)
 {
     /* temporary : 0 interpreted as "unknown" during transition period.
      * Users willing to specify "unknown" **must** use ZSTD_CONTENTSIZE_UNKNOWN.
      * 0 will be interpreted as "empty" in the future.
      */
     U64 const pledgedSrcSize = (pss==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
     DEBUGLOG(4, "ZSTD_resetCStream: pledgedSrcSize = %u", (unsigned)pledgedSrcSize);
     FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
     return 0;
 }
 
 /*! ZSTD_initCStream_internal() :
  *  Note : for lib/compress only. Used by zstdmt_compress.c.
  *  Assumption 1 : params are valid
  *  Assumption 2 : either dict, or cdict, is defined, not both */
 size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
                     const void* dict, size_t dictSize, const ZSTD_CDict* cdict,
-                    ZSTD_CCtx_params params, unsigned long long pledgedSrcSize)
+                    const ZSTD_CCtx_params* params,
+                    unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_initCStream_internal");
     FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
-    assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
-    zcs->requestedParams = params;
+    assert(!ZSTD_isError(ZSTD_checkCParams(params->cParams)));
+    zcs->requestedParams = *params;
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
     if (dict) {
         FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) );
     } else {
         /* Dictionary is cleared if !cdict */
         FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) );
     }
     return 0;
 }
 
 /* ZSTD_initCStream_usingCDict_advanced() :
  * same as ZSTD_initCStream_usingCDict(), with control over frame parameters */
 size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs,
                                             const ZSTD_CDict* cdict,
                                             ZSTD_frameParameters fParams,
                                             unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTD_initCStream_usingCDict_advanced");
     FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
     zcs->requestedParams.fParams = fParams;
     FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) );
     return 0;
 }
 
 /* note : cdict must outlive compression session */
 size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict)
 {
     DEBUGLOG(4, "ZSTD_initCStream_usingCDict");
     FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) );
     return 0;
 }
 
 
 /* ZSTD_initCStream_advanced() :
  * pledgedSrcSize must be exact.
  * if srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN.
- * dict is loaded with default parameters ZSTD_dm_auto and ZSTD_dlm_byCopy. */
+ * dict is loaded with default parameters ZSTD_dct_auto and ZSTD_dlm_byCopy. */
 size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
                                  const void* dict, size_t dictSize,
                                  ZSTD_parameters params, unsigned long long pss)
 {
     /* for compatibility with older programs relying on this behavior.
      * Users should now specify ZSTD_CONTENTSIZE_UNKNOWN.
      * This line will be removed in the future.
      */
     U64 const pledgedSrcSize = (pss==0 && params.fParams.contentSizeFlag==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
     DEBUGLOG(4, "ZSTD_initCStream_advanced");
     FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
     FORWARD_IF_ERROR( ZSTD_checkCParams(params.cParams) );
-    zcs->requestedParams = ZSTD_assignParamsToCCtxParams(zcs->requestedParams, params);
+    zcs->requestedParams = ZSTD_assignParamsToCCtxParams(&zcs->requestedParams, params);
     FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) );
     return 0;
 }
 
 size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel)
 {
     DEBUGLOG(4, "ZSTD_initCStream_usingDict");
     FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) );
     FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) );
     return 0;
 }
 
 size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pss)
 {
     /* temporary : 0 interpreted as "unknown" during transition period.
      * Users willing to specify "unknown" **must** use ZSTD_CONTENTSIZE_UNKNOWN.
      * 0 will be interpreted as "empty" in the future.
      */
     U64 const pledgedSrcSize = (pss==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
     DEBUGLOG(4, "ZSTD_initCStream_srcSize");
     FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, NULL) );
     FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) );
     FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) );
     return 0;
 }
 
 size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel)
 {
     DEBUGLOG(4, "ZSTD_initCStream");
     FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, NULL) );
     FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) );
     return 0;
 }
 
 /*======   Compression   ======*/
 
 static size_t ZSTD_nextInputSizeHint(const ZSTD_CCtx* cctx)
 {
     size_t hintInSize = cctx->inBuffTarget - cctx->inBuffPos;
     if (hintInSize==0) hintInSize = cctx->blockSize;
     return hintInSize;
 }
 
 static size_t ZSTD_limitCopy(void* dst, size_t dstCapacity,
                        const void* src, size_t srcSize)
 {
     size_t const length = MIN(dstCapacity, srcSize);
     if (length) memcpy(dst, src, length);
     return length;
 }
 
 /** ZSTD_compressStream_generic():
  *  internal function for all *compressStream*() variants
  *  non-static, because can be called from zstdmt_compress.c
  * @return : hint size for next input */
 static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                                           ZSTD_outBuffer* output,
                                           ZSTD_inBuffer* input,
                                           ZSTD_EndDirective const flushMode)
 {
     const char* const istart = (const char*)input->src;
     const char* const iend = istart + input->size;
     const char* ip = istart + input->pos;
     char* const ostart = (char*)output->dst;
     char* const oend = ostart + output->size;
     char* op = ostart + output->pos;
     U32 someMoreWork = 1;
 
     /* check expectations */
     DEBUGLOG(5, "ZSTD_compressStream_generic, flush=%u", (unsigned)flushMode);
     assert(zcs->inBuff != NULL);
     assert(zcs->inBuffSize > 0);
     assert(zcs->outBuff !=  NULL);
     assert(zcs->outBuffSize > 0);
     assert(output->pos <= output->size);
     assert(input->pos <= input->size);
 
     while (someMoreWork) {
         switch(zcs->streamStage)
         {
         case zcss_init:
             RETURN_ERROR(init_missing, "call ZSTD_initCStream() first!");
 
         case zcss_load:
             if ( (flushMode == ZSTD_e_end)
               && ((size_t)(oend-op) >= ZSTD_compressBound(iend-ip))  /* enough dstCapacity */
               && (zcs->inBuffPos == 0) ) {
                 /* shortcut to compression pass directly into output buffer */
                 size_t const cSize = ZSTD_compressEnd(zcs,
                                                 op, oend-op, ip, iend-ip);
                 DEBUGLOG(4, "ZSTD_compressEnd : cSize=%u", (unsigned)cSize);
                 FORWARD_IF_ERROR(cSize);
                 ip = iend;
                 op += cSize;
                 zcs->frameEnded = 1;
                 ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
                 someMoreWork = 0; break;
             }
             /* complete loading into inBuffer */
             {   size_t const toLoad = zcs->inBuffTarget - zcs->inBuffPos;
                 size_t const loaded = ZSTD_limitCopy(
                                         zcs->inBuff + zcs->inBuffPos, toLoad,
                                         ip, iend-ip);
                 zcs->inBuffPos += loaded;
                 ip += loaded;
                 if ( (flushMode == ZSTD_e_continue)
                   && (zcs->inBuffPos < zcs->inBuffTarget) ) {
                     /* not enough input to fill full block : stop here */
                     someMoreWork = 0; break;
                 }
                 if ( (flushMode == ZSTD_e_flush)
                   && (zcs->inBuffPos == zcs->inToCompress) ) {
                     /* empty */
                     someMoreWork = 0; break;
                 }
             }
             /* compress current block (note : this stage cannot be stopped in the middle) */
             DEBUGLOG(5, "stream compression stage (flushMode==%u)", flushMode);
             {   void* cDst;
                 size_t cSize;
                 size_t const iSize = zcs->inBuffPos - zcs->inToCompress;
                 size_t oSize = oend-op;
                 unsigned const lastBlock = (flushMode == ZSTD_e_end) && (ip==iend);
                 if (oSize >= ZSTD_compressBound(iSize))
                     cDst = op;   /* compress into output buffer, to skip flush stage */
                 else
                     cDst = zcs->outBuff, oSize = zcs->outBuffSize;
                 cSize = lastBlock ?
                         ZSTD_compressEnd(zcs, cDst, oSize,
                                     zcs->inBuff + zcs->inToCompress, iSize) :
                         ZSTD_compressContinue(zcs, cDst, oSize,
                                     zcs->inBuff + zcs->inToCompress, iSize);
                 FORWARD_IF_ERROR(cSize);
                 zcs->frameEnded = lastBlock;
                 /* prepare next block */
                 zcs->inBuffTarget = zcs->inBuffPos + zcs->blockSize;
                 if (zcs->inBuffTarget > zcs->inBuffSize)
                     zcs->inBuffPos = 0, zcs->inBuffTarget = zcs->blockSize;
                 DEBUGLOG(5, "inBuffTarget:%u / inBuffSize:%u",
                          (unsigned)zcs->inBuffTarget, (unsigned)zcs->inBuffSize);
                 if (!lastBlock)
                     assert(zcs->inBuffTarget <= zcs->inBuffSize);
                 zcs->inToCompress = zcs->inBuffPos;
                 if (cDst == op) {  /* no need to flush */
                     op += cSize;
                     if (zcs->frameEnded) {
                         DEBUGLOG(5, "Frame completed directly in outBuffer");
                         someMoreWork = 0;
                         ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
                     }
                     break;
                 }
                 zcs->outBuffContentSize = cSize;
                 zcs->outBuffFlushedSize = 0;
                 zcs->streamStage = zcss_flush; /* pass-through to flush stage */
             }
 	    /* fall-through */
         case zcss_flush:
             DEBUGLOG(5, "flush stage");
             {   size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
                 size_t const flushed = ZSTD_limitCopy(op, (size_t)(oend-op),
                             zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
                 DEBUGLOG(5, "toFlush: %u into %u ==> flushed: %u",
                             (unsigned)toFlush, (unsigned)(oend-op), (unsigned)flushed);
                 op += flushed;
                 zcs->outBuffFlushedSize += flushed;
                 if (toFlush!=flushed) {
                     /* flush not fully completed, presumably because dst is too small */
                     assert(op==oend);
                     someMoreWork = 0;
                     break;
                 }
                 zcs->outBuffContentSize = zcs->outBuffFlushedSize = 0;
                 if (zcs->frameEnded) {
                     DEBUGLOG(5, "Frame completed on flush");
                     someMoreWork = 0;
                     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
                     break;
                 }
                 zcs->streamStage = zcss_load;
                 break;
             }
 
         default: /* impossible */
             assert(0);
         }
     }
 
     input->pos = ip - istart;
     output->pos = op - ostart;
     if (zcs->frameEnded) return 0;
     return ZSTD_nextInputSizeHint(zcs);
 }
 
 static size_t ZSTD_nextInputSizeHint_MTorST(const ZSTD_CCtx* cctx)
 {
 #ifdef ZSTD_MULTITHREAD
     if (cctx->appliedParams.nbWorkers >= 1) {
         assert(cctx->mtctx != NULL);
         return ZSTDMT_nextInputSizeHint(cctx->mtctx);
     }
 #endif
     return ZSTD_nextInputSizeHint(cctx);
 
 }
 
 size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
     FORWARD_IF_ERROR( ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue) );
     return ZSTD_nextInputSizeHint_MTorST(zcs);
 }
 
 
 size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
                              ZSTD_outBuffer* output,
                              ZSTD_inBuffer* input,
                              ZSTD_EndDirective endOp)
 {
     DEBUGLOG(5, "ZSTD_compressStream2, endOp=%u ", (unsigned)endOp);
     /* check conditions */
     RETURN_ERROR_IF(output->pos > output->size, GENERIC);
     RETURN_ERROR_IF(input->pos  > input->size, GENERIC);
     assert(cctx!=NULL);
 
     /* transparent initialization stage */
     if (cctx->streamStage == zcss_init) {
         ZSTD_CCtx_params params = cctx->requestedParams;
         ZSTD_prefixDict const prefixDict = cctx->prefixDict;
         FORWARD_IF_ERROR( ZSTD_initLocalDict(cctx) ); /* Init the local dict if present. */
         memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));   /* single usage */
         assert(prefixDict.dict==NULL || cctx->cdict==NULL);    /* only one can be set */
         DEBUGLOG(4, "ZSTD_compressStream2 : transparent init stage");
         if (endOp == ZSTD_e_end) cctx->pledgedSrcSizePlusOne = input->size + 1;  /* auto-fix pledgedSrcSize */
         params.cParams = ZSTD_getCParamsFromCCtxParams(
                 &cctx->requestedParams, cctx->pledgedSrcSizePlusOne-1, 0 /*dictSize*/);
 
 
 #ifdef ZSTD_MULTITHREAD
         if ((cctx->pledgedSrcSizePlusOne-1) <= ZSTDMT_JOBSIZE_MIN) {
             params.nbWorkers = 0; /* do not invoke multi-threading when src size is too small */
         }
         if (params.nbWorkers > 0) {
             /* mt context creation */
             if (cctx->mtctx == NULL) {
                 DEBUGLOG(4, "ZSTD_compressStream2: creating new mtctx for nbWorkers=%u",
                             params.nbWorkers);
-                cctx->mtctx = ZSTDMT_createCCtx_advanced(params.nbWorkers, cctx->customMem);
+                cctx->mtctx = ZSTDMT_createCCtx_advanced((U32)params.nbWorkers, cctx->customMem);
                 RETURN_ERROR_IF(cctx->mtctx == NULL, memory_allocation);
             }
             /* mt compression */
             DEBUGLOG(4, "call ZSTDMT_initCStream_internal as nbWorkers=%u", params.nbWorkers);
             FORWARD_IF_ERROR( ZSTDMT_initCStream_internal(
                         cctx->mtctx,
                         prefixDict.dict, prefixDict.dictSize, ZSTD_dct_rawContent,
                         cctx->cdict, params, cctx->pledgedSrcSizePlusOne-1) );
             cctx->streamStage = zcss_load;
             cctx->appliedParams.nbWorkers = params.nbWorkers;
         } else
 #endif
         {   FORWARD_IF_ERROR( ZSTD_resetCStream_internal(cctx,
                             prefixDict.dict, prefixDict.dictSize, prefixDict.dictContentType,
                             cctx->cdict,
                             params, cctx->pledgedSrcSizePlusOne-1) );
             assert(cctx->streamStage == zcss_load);
             assert(cctx->appliedParams.nbWorkers == 0);
     }   }
     /* end of transparent initialization stage */
 
     /* compression stage */
 #ifdef ZSTD_MULTITHREAD
     if (cctx->appliedParams.nbWorkers > 0) {
         int const forceMaxProgress = (endOp == ZSTD_e_flush || endOp == ZSTD_e_end);
         size_t flushMin;
         assert(forceMaxProgress || endOp == ZSTD_e_continue /* Protection for a new flush type */);
         if (cctx->cParamsChanged) {
             ZSTDMT_updateCParams_whileCompressing(cctx->mtctx, &cctx->requestedParams);
             cctx->cParamsChanged = 0;
         }
         do {
             flushMin = ZSTDMT_compressStream_generic(cctx->mtctx, output, input, endOp);
             if ( ZSTD_isError(flushMin)
               || (endOp == ZSTD_e_end && flushMin == 0) ) { /* compression completed */
                 ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
             }
             FORWARD_IF_ERROR(flushMin);
         } while (forceMaxProgress && flushMin != 0 && output->pos < output->size);
         DEBUGLOG(5, "completed ZSTD_compressStream2 delegating to ZSTDMT_compressStream_generic");
         /* Either we don't require maximum forward progress, we've finished the
          * flush, or we are out of output space.
          */
         assert(!forceMaxProgress || flushMin == 0 || output->pos == output->size);
         return flushMin;
     }
 #endif
     FORWARD_IF_ERROR( ZSTD_compressStream_generic(cctx, output, input, endOp) );
     DEBUGLOG(5, "completed ZSTD_compressStream2");
     return cctx->outBuffContentSize - cctx->outBuffFlushedSize; /* remaining to flush */
 }
 
 size_t ZSTD_compressStream2_simpleArgs (
                             ZSTD_CCtx* cctx,
                             void* dst, size_t dstCapacity, size_t* dstPos,
                       const void* src, size_t srcSize, size_t* srcPos,
                             ZSTD_EndDirective endOp)
 {
     ZSTD_outBuffer output = { dst, dstCapacity, *dstPos };
     ZSTD_inBuffer  input  = { src, srcSize, *srcPos };
     /* ZSTD_compressStream2() will check validity of dstPos and srcPos */
     size_t const cErr = ZSTD_compressStream2(cctx, &output, &input, endOp);
     *dstPos = output.pos;
     *srcPos = input.pos;
     return cErr;
 }
 
 size_t ZSTD_compress2(ZSTD_CCtx* cctx,
                       void* dst, size_t dstCapacity,
                       const void* src, size_t srcSize)
 {
     ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
     {   size_t oPos = 0;
         size_t iPos = 0;
         size_t const result = ZSTD_compressStream2_simpleArgs(cctx,
                                         dst, dstCapacity, &oPos,
                                         src, srcSize, &iPos,
                                         ZSTD_e_end);
         FORWARD_IF_ERROR(result);
         if (result != 0) {  /* compression not completed, due to lack of output space */
             assert(oPos == dstCapacity);
             RETURN_ERROR(dstSize_tooSmall);
         }
         assert(iPos == srcSize);   /* all input is expected consumed */
         return oPos;
     }
 }
 
 /*======   Finalize   ======*/
 
 /*! ZSTD_flushStream() :
  * @return : amount of data remaining to flush */
 size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
 {
     ZSTD_inBuffer input = { NULL, 0, 0 };
     return ZSTD_compressStream2(zcs, output, &input, ZSTD_e_flush);
 }
 
 
 size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
 {
     ZSTD_inBuffer input = { NULL, 0, 0 };
     size_t const remainingToFlush = ZSTD_compressStream2(zcs, output, &input, ZSTD_e_end);
     FORWARD_IF_ERROR( remainingToFlush );
     if (zcs->appliedParams.nbWorkers > 0) return remainingToFlush;   /* minimal estimation */
     /* single thread mode : attempt to calculate remaining to flush more precisely */
     {   size_t const lastBlockSize = zcs->frameEnded ? 0 : ZSTD_BLOCKHEADERSIZE;
         size_t const checksumSize = (size_t)(zcs->frameEnded ? 0 : zcs->appliedParams.fParams.checksumFlag * 4);
         size_t const toFlush = remainingToFlush + lastBlockSize + checksumSize;
         DEBUGLOG(4, "ZSTD_endStream : remaining to flush : %u", (unsigned)toFlush);
         return toFlush;
     }
 }
 
 
 /*-=====  Pre-defined compression levels  =====-*/
 
 #define ZSTD_MAX_CLEVEL     22
 int ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
 int ZSTD_minCLevel(void) { return (int)-ZSTD_TARGETLENGTH_MAX; }
 
 static const ZSTD_compressionParameters ZSTD_defaultCParameters[4][ZSTD_MAX_CLEVEL+1] = {
 {   /* "default" - for any srcSize > 256 KB */
     /* W,  C,  H,  S,  L, TL, strat */
     { 19, 12, 13,  1,  6,  1, ZSTD_fast    },  /* base for negative levels */
     { 19, 13, 14,  1,  7,  0, ZSTD_fast    },  /* level  1 */
     { 20, 15, 16,  1,  6,  0, ZSTD_fast    },  /* level  2 */
-    { 21, 16, 17,  1,  5,  1, ZSTD_dfast   },  /* level  3 */
-    { 21, 18, 18,  1,  5,  1, ZSTD_dfast   },  /* level  4 */
+    { 21, 16, 17,  1,  5,  0, ZSTD_dfast   },  /* level  3 */
+    { 21, 18, 18,  1,  5,  0, ZSTD_dfast   },  /* level  4 */
     { 21, 18, 19,  2,  5,  2, ZSTD_greedy  },  /* level  5 */
     { 21, 19, 19,  3,  5,  4, ZSTD_greedy  },  /* level  6 */
     { 21, 19, 19,  3,  5,  8, ZSTD_lazy    },  /* level  7 */
     { 21, 19, 19,  3,  5, 16, ZSTD_lazy2   },  /* level  8 */
     { 21, 19, 20,  4,  5, 16, ZSTD_lazy2   },  /* level  9 */
     { 22, 20, 21,  4,  5, 16, ZSTD_lazy2   },  /* level 10 */
     { 22, 21, 22,  4,  5, 16, ZSTD_lazy2   },  /* level 11 */
     { 22, 21, 22,  5,  5, 16, ZSTD_lazy2   },  /* level 12 */
     { 22, 21, 22,  5,  5, 32, ZSTD_btlazy2 },  /* level 13 */
     { 22, 22, 23,  5,  5, 32, ZSTD_btlazy2 },  /* level 14 */
     { 22, 23, 23,  6,  5, 32, ZSTD_btlazy2 },  /* level 15 */
     { 22, 22, 22,  5,  5, 48, ZSTD_btopt   },  /* level 16 */
     { 23, 23, 22,  5,  4, 64, ZSTD_btopt   },  /* level 17 */
     { 23, 23, 22,  6,  3, 64, ZSTD_btultra },  /* level 18 */
     { 23, 24, 22,  7,  3,256, ZSTD_btultra2},  /* level 19 */
     { 25, 25, 23,  7,  3,256, ZSTD_btultra2},  /* level 20 */
     { 26, 26, 24,  7,  3,512, ZSTD_btultra2},  /* level 21 */
     { 27, 27, 25,  9,  3,999, ZSTD_btultra2},  /* level 22 */
 },
 {   /* for srcSize <= 256 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 18, 12, 13,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
     { 18, 13, 14,  1,  6,  0, ZSTD_fast    },  /* level  1 */
-    { 18, 14, 14,  1,  5,  1, ZSTD_dfast   },  /* level  2 */
-    { 18, 16, 16,  1,  4,  1, ZSTD_dfast   },  /* level  3 */
+    { 18, 14, 14,  1,  5,  0, ZSTD_dfast   },  /* level  2 */
+    { 18, 16, 16,  1,  4,  0, ZSTD_dfast   },  /* level  3 */
     { 18, 16, 17,  2,  5,  2, ZSTD_greedy  },  /* level  4.*/
     { 18, 18, 18,  3,  5,  2, ZSTD_greedy  },  /* level  5.*/
     { 18, 18, 19,  3,  5,  4, ZSTD_lazy    },  /* level  6.*/
     { 18, 18, 19,  4,  4,  4, ZSTD_lazy    },  /* level  7 */
     { 18, 18, 19,  4,  4,  8, ZSTD_lazy2   },  /* level  8 */
     { 18, 18, 19,  5,  4,  8, ZSTD_lazy2   },  /* level  9 */
     { 18, 18, 19,  6,  4,  8, ZSTD_lazy2   },  /* level 10 */
     { 18, 18, 19,  5,  4, 12, ZSTD_btlazy2 },  /* level 11.*/
     { 18, 19, 19,  7,  4, 12, ZSTD_btlazy2 },  /* level 12.*/
     { 18, 18, 19,  4,  4, 16, ZSTD_btopt   },  /* level 13 */
     { 18, 18, 19,  4,  3, 32, ZSTD_btopt   },  /* level 14.*/
     { 18, 18, 19,  6,  3,128, ZSTD_btopt   },  /* level 15.*/
     { 18, 19, 19,  6,  3,128, ZSTD_btultra },  /* level 16.*/
     { 18, 19, 19,  8,  3,256, ZSTD_btultra },  /* level 17.*/
     { 18, 19, 19,  6,  3,128, ZSTD_btultra2},  /* level 18.*/
     { 18, 19, 19,  8,  3,256, ZSTD_btultra2},  /* level 19.*/
     { 18, 19, 19, 10,  3,512, ZSTD_btultra2},  /* level 20.*/
     { 18, 19, 19, 12,  3,512, ZSTD_btultra2},  /* level 21.*/
     { 18, 19, 19, 13,  3,999, ZSTD_btultra2},  /* level 22.*/
 },
 {   /* for srcSize <= 128 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 17, 12, 12,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
     { 17, 12, 13,  1,  6,  0, ZSTD_fast    },  /* level  1 */
     { 17, 13, 15,  1,  5,  0, ZSTD_fast    },  /* level  2 */
-    { 17, 15, 16,  2,  5,  1, ZSTD_dfast   },  /* level  3 */
-    { 17, 17, 17,  2,  4,  1, ZSTD_dfast   },  /* level  4 */
+    { 17, 15, 16,  2,  5,  0, ZSTD_dfast   },  /* level  3 */
+    { 17, 17, 17,  2,  4,  0, ZSTD_dfast   },  /* level  4 */
     { 17, 16, 17,  3,  4,  2, ZSTD_greedy  },  /* level  5 */
     { 17, 17, 17,  3,  4,  4, ZSTD_lazy    },  /* level  6 */
     { 17, 17, 17,  3,  4,  8, ZSTD_lazy2   },  /* level  7 */
     { 17, 17, 17,  4,  4,  8, ZSTD_lazy2   },  /* level  8 */
     { 17, 17, 17,  5,  4,  8, ZSTD_lazy2   },  /* level  9 */
     { 17, 17, 17,  6,  4,  8, ZSTD_lazy2   },  /* level 10 */
     { 17, 17, 17,  5,  4,  8, ZSTD_btlazy2 },  /* level 11 */
     { 17, 18, 17,  7,  4, 12, ZSTD_btlazy2 },  /* level 12 */
     { 17, 18, 17,  3,  4, 12, ZSTD_btopt   },  /* level 13.*/
     { 17, 18, 17,  4,  3, 32, ZSTD_btopt   },  /* level 14.*/
     { 17, 18, 17,  6,  3,256, ZSTD_btopt   },  /* level 15.*/
     { 17, 18, 17,  6,  3,128, ZSTD_btultra },  /* level 16.*/
     { 17, 18, 17,  8,  3,256, ZSTD_btultra },  /* level 17.*/
     { 17, 18, 17, 10,  3,512, ZSTD_btultra },  /* level 18.*/
     { 17, 18, 17,  5,  3,256, ZSTD_btultra2},  /* level 19.*/
     { 17, 18, 17,  7,  3,512, ZSTD_btultra2},  /* level 20.*/
     { 17, 18, 17,  9,  3,512, ZSTD_btultra2},  /* level 21.*/
     { 17, 18, 17, 11,  3,999, ZSTD_btultra2},  /* level 22.*/
 },
 {   /* for srcSize <= 16 KB */
     /* W,  C,  H,  S,  L,  T, strat */
     { 14, 12, 13,  1,  5,  1, ZSTD_fast    },  /* base for negative levels */
     { 14, 14, 15,  1,  5,  0, ZSTD_fast    },  /* level  1 */
     { 14, 14, 15,  1,  4,  0, ZSTD_fast    },  /* level  2 */
-    { 14, 14, 15,  2,  4,  1, ZSTD_dfast   },  /* level  3 */
+    { 14, 14, 15,  2,  4,  0, ZSTD_dfast   },  /* level  3 */
     { 14, 14, 14,  4,  4,  2, ZSTD_greedy  },  /* level  4 */
     { 14, 14, 14,  3,  4,  4, ZSTD_lazy    },  /* level  5.*/
     { 14, 14, 14,  4,  4,  8, ZSTD_lazy2   },  /* level  6 */
     { 14, 14, 14,  6,  4,  8, ZSTD_lazy2   },  /* level  7 */
     { 14, 14, 14,  8,  4,  8, ZSTD_lazy2   },  /* level  8.*/
     { 14, 15, 14,  5,  4,  8, ZSTD_btlazy2 },  /* level  9.*/
     { 14, 15, 14,  9,  4,  8, ZSTD_btlazy2 },  /* level 10.*/
     { 14, 15, 14,  3,  4, 12, ZSTD_btopt   },  /* level 11.*/
     { 14, 15, 14,  4,  3, 24, ZSTD_btopt   },  /* level 12.*/
     { 14, 15, 14,  5,  3, 32, ZSTD_btultra },  /* level 13.*/
     { 14, 15, 15,  6,  3, 64, ZSTD_btultra },  /* level 14.*/
     { 14, 15, 15,  7,  3,256, ZSTD_btultra },  /* level 15.*/
     { 14, 15, 15,  5,  3, 48, ZSTD_btultra2},  /* level 16.*/
     { 14, 15, 15,  6,  3,128, ZSTD_btultra2},  /* level 17.*/
     { 14, 15, 15,  7,  3,256, ZSTD_btultra2},  /* level 18.*/
     { 14, 15, 15,  8,  3,256, ZSTD_btultra2},  /* level 19.*/
     { 14, 15, 15,  8,  3,512, ZSTD_btultra2},  /* level 20.*/
     { 14, 15, 15,  9,  3,512, ZSTD_btultra2},  /* level 21.*/
     { 14, 15, 15, 10,  3,999, ZSTD_btultra2},  /* level 22.*/
 },
 };
 
 /*! ZSTD_getCParams() :
  * @return ZSTD_compressionParameters structure for a selected compression level, srcSize and dictSize.
  *  Size values are optional, provide 0 if not known or unused */
 ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize)
 {
     size_t const addedSize = srcSizeHint ? 0 : 500;
     U64 const rSize = srcSizeHint+dictSize ? srcSizeHint+dictSize+addedSize : ZSTD_CONTENTSIZE_UNKNOWN;  /* intentional overflow for srcSizeHint == ZSTD_CONTENTSIZE_UNKNOWN */
     U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB);
     int row = compressionLevel;
     DEBUGLOG(5, "ZSTD_getCParams (cLevel=%i)", compressionLevel);
     if (compressionLevel == 0) row = ZSTD_CLEVEL_DEFAULT;   /* 0 == default */
     if (compressionLevel < 0) row = 0;   /* entry 0 is baseline for fast mode */
     if (compressionLevel > ZSTD_MAX_CLEVEL) row = ZSTD_MAX_CLEVEL;
     {   ZSTD_compressionParameters cp = ZSTD_defaultCParameters[tableID][row];
         if (compressionLevel < 0) cp.targetLength = (unsigned)(-compressionLevel);   /* acceleration factor */
         return ZSTD_adjustCParams_internal(cp, srcSizeHint, dictSize);               /* refine parameters based on srcSize & dictSize */
     }
 }
 
 /*! ZSTD_getParams() :
  *  same idea as ZSTD_getCParams()
  * @return a `ZSTD_parameters` structure (instead of `ZSTD_compressionParameters`).
  *  Fields of `ZSTD_frameParameters` are set to default values */
 ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize) {
     ZSTD_parameters params;
     ZSTD_compressionParameters const cParams = ZSTD_getCParams(compressionLevel, srcSizeHint, dictSize);
     DEBUGLOG(5, "ZSTD_getParams (cLevel=%i)", compressionLevel);
     memset(¶ms, 0, sizeof(params));
     params.cParams = cParams;
     params.fParams.contentSizeFlag = 1;
     return params;
 }
Index: head/sys/contrib/zstd/lib/compress/zstd_compress_internal.h
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_compress_internal.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_compress_internal.h	(revision 354777)
@@ -1,931 +1,1003 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 /* This header contains definitions
  * that shall **only** be used by modules within lib/compress.
  */
 
 #ifndef ZSTD_COMPRESS_H
 #define ZSTD_COMPRESS_H
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include "zstd_internal.h"
+#include "zstd_cwksp.h"
 #ifdef ZSTD_MULTITHREAD
 #  include "zstdmt_compress.h"
 #endif
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /*-*************************************
 *  Constants
 ***************************************/
 #define kSearchStrength      8
 #define HASH_READ_SIZE       8
 #define ZSTD_DUBT_UNSORTED_MARK 1   /* For btlazy2 strategy, index ZSTD_DUBT_UNSORTED_MARK==1 means "unsorted".
                                        It could be confused for a real successor at index "1", if sorted as larger than its predecessor.
                                        It's not a big deal though : candidate will just be sorted again.
                                        Additionally, candidate position 1 will be lost.
                                        But candidate 1 cannot hide a large tree of candidates, so it's a minimal loss.
                                        The benefit is that ZSTD_DUBT_UNSORTED_MARK cannot be mishandled after table re-use with a different strategy.
                                        This constant is required by ZSTD_compressBlock_btlazy2() and ZSTD_reduceTable_internal() */
 
 
 /*-*************************************
 *  Context memory management
 ***************************************/
 typedef enum { ZSTDcs_created=0, ZSTDcs_init, ZSTDcs_ongoing, ZSTDcs_ending } ZSTD_compressionStage_e;
 typedef enum { zcss_init=0, zcss_load, zcss_flush } ZSTD_cStreamStage;
 
 typedef struct ZSTD_prefixDict_s {
     const void* dict;
     size_t dictSize;
     ZSTD_dictContentType_e dictContentType;
 } ZSTD_prefixDict;
 
 typedef struct {
     void* dictBuffer;
     void const* dict;
     size_t dictSize;
     ZSTD_dictContentType_e dictContentType;
     ZSTD_CDict* cdict;
 } ZSTD_localDict;
 
 typedef struct {
     U32 CTable[HUF_CTABLE_SIZE_U32(255)];
     HUF_repeat repeatMode;
 } ZSTD_hufCTables_t;
 
 typedef struct {
     FSE_CTable offcodeCTable[FSE_CTABLE_SIZE_U32(OffFSELog, MaxOff)];
     FSE_CTable matchlengthCTable[FSE_CTABLE_SIZE_U32(MLFSELog, MaxML)];
     FSE_CTable litlengthCTable[FSE_CTABLE_SIZE_U32(LLFSELog, MaxLL)];
     FSE_repeat offcode_repeatMode;
     FSE_repeat matchlength_repeatMode;
     FSE_repeat litlength_repeatMode;
 } ZSTD_fseCTables_t;
 
 typedef struct {
     ZSTD_hufCTables_t huf;
     ZSTD_fseCTables_t fse;
 } ZSTD_entropyCTables_t;
 
 typedef struct {
     U32 off;
     U32 len;
 } ZSTD_match_t;
 
 typedef struct {
     int price;
     U32 off;
     U32 mlen;
     U32 litlen;
     U32 rep[ZSTD_REP_NUM];
 } ZSTD_optimal_t;
 
 typedef enum { zop_dynamic=0, zop_predef } ZSTD_OptPrice_e;
 
 typedef struct {
     /* All tables are allocated inside cctx->workspace by ZSTD_resetCCtx_internal() */
     unsigned* litFreq;           /* table of literals statistics, of size 256 */
     unsigned* litLengthFreq;     /* table of litLength statistics, of size (MaxLL+1) */
     unsigned* matchLengthFreq;   /* table of matchLength statistics, of size (MaxML+1) */
     unsigned* offCodeFreq;       /* table of offCode statistics, of size (MaxOff+1) */
     ZSTD_match_t* matchTable;    /* list of found matches, of size ZSTD_OPT_NUM+1 */
     ZSTD_optimal_t* priceTable;  /* All positions tracked by optimal parser, of size ZSTD_OPT_NUM+1 */
 
     U32  litSum;                 /* nb of literals */
     U32  litLengthSum;           /* nb of litLength codes */
     U32  matchLengthSum;         /* nb of matchLength codes */
     U32  offCodeSum;             /* nb of offset codes */
     U32  litSumBasePrice;        /* to compare to log2(litfreq) */
     U32  litLengthSumBasePrice;  /* to compare to log2(llfreq)  */
     U32  matchLengthSumBasePrice;/* to compare to log2(mlfreq)  */
     U32  offCodeSumBasePrice;    /* to compare to log2(offreq)  */
     ZSTD_OptPrice_e priceType;   /* prices can be determined dynamically, or follow a pre-defined cost structure */
     const ZSTD_entropyCTables_t* symbolCosts;  /* pre-calculated dictionary statistics */
     ZSTD_literalCompressionMode_e literalCompressionMode;
 } optState_t;
 
 typedef struct {
   ZSTD_entropyCTables_t entropy;
   U32 rep[ZSTD_REP_NUM];
 } ZSTD_compressedBlockState_t;
 
 typedef struct {
     BYTE const* nextSrc;    /* next block here to continue on current prefix */
     BYTE const* base;       /* All regular indexes relative to this position */
     BYTE const* dictBase;   /* extDict indexes relative to this position */
     U32 dictLimit;          /* below that point, need extDict */
     U32 lowLimit;           /* below that point, no more valid data */
 } ZSTD_window_t;
 
 typedef struct ZSTD_matchState_t ZSTD_matchState_t;
 struct ZSTD_matchState_t {
     ZSTD_window_t window;   /* State for window round buffer management */
-    U32 loadedDictEnd;      /* index of end of dictionary, within context's referential. When dict referential is copied into active context (i.e. not attached), effectively same value as dictSize, since referential starts from zero */
+    U32 loadedDictEnd;      /* index of end of dictionary, within context's referential.
+                             * When loadedDictEnd != 0, a dictionary is in use, and still valid.
+                             * This relies on a mechanism to set loadedDictEnd=0 when dictionary is no longer within distance.
+                             * Such mechanism is provided within ZSTD_window_enforceMaxDist() and ZSTD_checkDictValidity().
+                             * When dict referential is copied into active context (i.e. not attached),
+                             * loadedDictEnd == dictSize, since referential starts from zero.
+                             */
     U32 nextToUpdate;       /* index from which to continue table update */
-    U32 hashLog3;           /* dispatch table : larger == faster, more memory */
+    U32 hashLog3;           /* dispatch table for matches of len==3 : larger == faster, more memory */
     U32* hashTable;
     U32* hashTable3;
     U32* chainTable;
     optState_t opt;         /* optimal parser state */
     const ZSTD_matchState_t* dictMatchState;
     ZSTD_compressionParameters cParams;
 };
 
 typedef struct {
     ZSTD_compressedBlockState_t* prevCBlock;
     ZSTD_compressedBlockState_t* nextCBlock;
     ZSTD_matchState_t matchState;
 } ZSTD_blockState_t;
 
 typedef struct {
     U32 offset;
     U32 checksum;
 } ldmEntry_t;
 
 typedef struct {
     ZSTD_window_t window;   /* State for the window round buffer management */
     ldmEntry_t* hashTable;
     BYTE* bucketOffsets;    /* Next position in bucket to insert entry */
     U64 hashPower;          /* Used to compute the rolling hash.
                              * Depends on ldmParams.minMatchLength */
 } ldmState_t;
 
 typedef struct {
     U32 enableLdm;          /* 1 if enable long distance matching */
     U32 hashLog;            /* Log size of hashTable */
     U32 bucketSizeLog;      /* Log bucket size for collision resolution, at most 8 */
     U32 minMatchLength;     /* Minimum match length */
     U32 hashRateLog;       /* Log number of entries to skip */
     U32 windowLog;          /* Window log for the LDM */
 } ldmParams_t;
 
 typedef struct {
     U32 offset;
     U32 litLength;
     U32 matchLength;
 } rawSeq;
 
 typedef struct {
   rawSeq* seq;     /* The start of the sequences */
   size_t pos;      /* The position where reading stopped. <= size. */
   size_t size;     /* The number of sequences. <= capacity. */
   size_t capacity; /* The capacity starting from `seq` pointer */
 } rawSeqStore_t;
 
+typedef struct {
+    int collectSequences;
+    ZSTD_Sequence* seqStart;
+    size_t seqIndex;
+    size_t maxSequences;
+} SeqCollector;
+
 struct ZSTD_CCtx_params_s {
     ZSTD_format_e format;
     ZSTD_compressionParameters cParams;
     ZSTD_frameParameters fParams;
 
     int compressionLevel;
     int forceWindow;           /* force back-references to respect limit of
                                 * 1< 63) ? ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
 }
 
 /* ZSTD_MLcode() :
  * note : mlBase = matchLength - MINMATCH;
  *        because it's the format it's stored in seqStore->sequences */
 MEM_STATIC U32 ZSTD_MLcode(U32 mlBase)
 {
     static const BYTE ML_Code[128] = { 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
                                       16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
                                       32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 36, 36, 37, 37, 37, 37,
                                       38, 38, 38, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 39, 39,
                                       40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40,
                                       41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41,
                                       42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42,
                                       42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42 };
     static const U32 ML_deltaCode = 36;
     return (mlBase > 127) ? ZSTD_highbit32(mlBase) + ML_deltaCode : ML_Code[mlBase];
 }
 
 /* ZSTD_cParam_withinBounds:
  * @return 1 if value is within cParam bounds,
  * 0 otherwise */
 MEM_STATIC int ZSTD_cParam_withinBounds(ZSTD_cParameter cParam, int value)
 {
     ZSTD_bounds const bounds = ZSTD_cParam_getBounds(cParam);
     if (ZSTD_isError(bounds.error)) return 0;
     if (value < bounds.lowerBound) return 0;
     if (value > bounds.upperBound) return 0;
     return 1;
 }
 
 /* ZSTD_minGain() :
  * minimum compression required
  * to generate a compress block or a compressed literals section.
  * note : use same formula for both situations */
 MEM_STATIC size_t ZSTD_minGain(size_t srcSize, ZSTD_strategy strat)
 {
     U32 const minlog = (strat>=ZSTD_btultra) ? (U32)(strat) - 1 : 6;
     ZSTD_STATIC_ASSERT(ZSTD_btultra == 8);
     assert(ZSTD_cParam_withinBounds(ZSTD_c_strategy, strat));
     return (srcSize >> minlog) + 2;
 }
 
+/*! ZSTD_safecopyLiterals() :
+ *  memcpy() function that won't read beyond more than WILDCOPY_OVERLENGTH bytes past ilimit_w.
+ *  Only called when the sequence ends past ilimit_w, so it only needs to be optimized for single
+ *  large copies.
+ */
+static void ZSTD_safecopyLiterals(BYTE* op, BYTE const* ip, BYTE const* const iend, BYTE const* ilimit_w) {
+    assert(iend > ilimit_w);
+    if (ip <= ilimit_w) {
+        ZSTD_wildcopy(op, ip, ilimit_w - ip, ZSTD_no_overlap);
+        op += ilimit_w - ip;
+        ip = ilimit_w;
+    }
+    while (ip < iend) *op++ = *ip++;
+}
+
 /*! ZSTD_storeSeq() :
- *  Store a sequence (literal length, literals, offset code and match length code) into seqStore_t.
- *  `offsetCode` : distance to match + 3 (values 1-3 are repCodes).
+ *  Store a sequence (litlen, litPtr, offCode and mlBase) into seqStore_t.
+ *  `offCode` : distance to match + ZSTD_REP_MOVE (values <= ZSTD_REP_MOVE are repCodes).
  *  `mlBase` : matchLength - MINMATCH
+ *  Allowed to overread literals up to litLimit.
 */
-MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const void* literals, U32 offsetCode, size_t mlBase)
+HINT_INLINE UNUSED_ATTR
+void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const BYTE* literals, const BYTE* litLimit, U32 offCode, size_t mlBase)
 {
+    BYTE const* const litLimit_w = litLimit - WILDCOPY_OVERLENGTH;
+    BYTE const* const litEnd = literals + litLength;
 #if defined(DEBUGLEVEL) && (DEBUGLEVEL >= 6)
     static const BYTE* g_start = NULL;
     if (g_start==NULL) g_start = (const BYTE*)literals;  /* note : index only works for compression within a single segment */
     {   U32 const pos = (U32)((const BYTE*)literals - g_start);
         DEBUGLOG(6, "Cpos%7u :%3u literals, match%4u bytes at offCode%7u",
-               pos, (U32)litLength, (U32)mlBase+MINMATCH, (U32)offsetCode);
+               pos, (U32)litLength, (U32)mlBase+MINMATCH, (U32)offCode);
     }
 #endif
     assert((size_t)(seqStorePtr->sequences - seqStorePtr->sequencesStart) < seqStorePtr->maxNbSeq);
     /* copy Literals */
     assert(seqStorePtr->maxNbLit <= 128 KB);
     assert(seqStorePtr->lit + litLength <= seqStorePtr->litStart + seqStorePtr->maxNbLit);
-    ZSTD_wildcopy(seqStorePtr->lit, literals, litLength, ZSTD_no_overlap);
+    assert(literals + litLength <= litLimit);
+    if (litEnd <= litLimit_w) {
+        /* Common case we can use wildcopy.
+	 * First copy 16 bytes, because literals are likely short.
+	 */
+        assert(WILDCOPY_OVERLENGTH >= 16);
+        ZSTD_copy16(seqStorePtr->lit, literals);
+        if (litLength > 16) {
+            ZSTD_wildcopy(seqStorePtr->lit+16, literals+16, (ptrdiff_t)litLength-16, ZSTD_no_overlap);
+        }
+    } else {
+        ZSTD_safecopyLiterals(seqStorePtr->lit, literals, litEnd, litLimit_w);
+    }
     seqStorePtr->lit += litLength;
 
     /* literal Length */
     if (litLength>0xFFFF) {
         assert(seqStorePtr->longLengthID == 0); /* there can only be a single long length */
         seqStorePtr->longLengthID = 1;
         seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
     }
     seqStorePtr->sequences[0].litLength = (U16)litLength;
 
     /* match offset */
-    seqStorePtr->sequences[0].offset = offsetCode + 1;
+    seqStorePtr->sequences[0].offset = offCode + 1;
 
     /* match Length */
     if (mlBase>0xFFFF) {
         assert(seqStorePtr->longLengthID == 0); /* there can only be a single long length */
         seqStorePtr->longLengthID = 2;
         seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
     }
     seqStorePtr->sequences[0].matchLength = (U16)mlBase;
 
     seqStorePtr->sequences++;
 }
 
 
 /*-*************************************
 *  Match length counter
 ***************************************/
 static unsigned ZSTD_NbCommonBytes (size_t val)
 {
     if (MEM_isLittleEndian()) {
         if (MEM_64bits()) {
 #       if defined(_MSC_VER) && defined(_WIN64)
             unsigned long r = 0;
             _BitScanForward64( &r, (U64)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 4)
             return (__builtin_ctzll((U64)val) >> 3);
 #       else
             static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2,
                                                      0, 3, 1, 3, 1, 4, 2, 7,
                                                      0, 2, 3, 6, 1, 5, 3, 5,
                                                      1, 3, 4, 4, 2, 5, 6, 7,
                                                      7, 0, 1, 2, 3, 3, 4, 6,
                                                      2, 6, 5, 5, 3, 4, 5, 6,
                                                      7, 1, 2, 4, 6, 4, 4, 5,
                                                      7, 2, 6, 5, 7, 6, 7, 7 };
             return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
 #       endif
         } else { /* 32 bits */
 #       if defined(_MSC_VER)
             unsigned long r=0;
             _BitScanForward( &r, (U32)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_ctz((U32)val) >> 3);
 #       else
             static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0,
                                                      3, 2, 2, 1, 3, 2, 0, 1,
                                                      3, 3, 1, 2, 2, 2, 2, 0,
                                                      3, 1, 2, 0, 1, 0, 1, 1 };
             return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
 #       endif
         }
     } else {  /* Big Endian CPU */
         if (MEM_64bits()) {
 #       if defined(_MSC_VER) && defined(_WIN64)
             unsigned long r = 0;
             _BitScanReverse64( &r, val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 4)
             return (__builtin_clzll(val) >> 3);
 #       else
             unsigned r;
             const unsigned n32 = sizeof(size_t)*4;   /* calculate this way due to compiler complaining in 32-bits mode */
             if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; }
             if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
             r += (!val);
             return r;
 #       endif
         } else { /* 32 bits */
 #       if defined(_MSC_VER)
             unsigned long r = 0;
             _BitScanReverse( &r, (unsigned long)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_clz((U32)val) >> 3);
 #       else
             unsigned r;
             if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
             r += (!val);
             return r;
 #       endif
     }   }
 }
 
 
 MEM_STATIC size_t ZSTD_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* const pInLimit)
 {
     const BYTE* const pStart = pIn;
     const BYTE* const pInLoopLimit = pInLimit - (sizeof(size_t)-1);
 
     if (pIn < pInLoopLimit) {
         { size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
           if (diff) return ZSTD_NbCommonBytes(diff); }
         pIn+=sizeof(size_t); pMatch+=sizeof(size_t);
         while (pIn < pInLoopLimit) {
             size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
             if (!diff) { pIn+=sizeof(size_t); pMatch+=sizeof(size_t); continue; }
             pIn += ZSTD_NbCommonBytes(diff);
             return (size_t)(pIn - pStart);
     }   }
     if (MEM_64bits() && (pIn<(pInLimit-3)) && (MEM_read32(pMatch) == MEM_read32(pIn))) { pIn+=4; pMatch+=4; }
     if ((pIn<(pInLimit-1)) && (MEM_read16(pMatch) == MEM_read16(pIn))) { pIn+=2; pMatch+=2; }
     if ((pIn> (32-h) ; }
 MEM_STATIC size_t ZSTD_hash3Ptr(const void* ptr, U32 h) { return ZSTD_hash3(MEM_readLE32(ptr), h); } /* only in zstd_opt.h */
 
 static const U32 prime4bytes = 2654435761U;
 static U32    ZSTD_hash4(U32 u, U32 h) { return (u * prime4bytes) >> (32-h) ; }
 static size_t ZSTD_hash4Ptr(const void* ptr, U32 h) { return ZSTD_hash4(MEM_read32(ptr), h); }
 
 static const U64 prime5bytes = 889523592379ULL;
 static size_t ZSTD_hash5(U64 u, U32 h) { return (size_t)(((u  << (64-40)) * prime5bytes) >> (64-h)) ; }
 static size_t ZSTD_hash5Ptr(const void* p, U32 h) { return ZSTD_hash5(MEM_readLE64(p), h); }
 
 static const U64 prime6bytes = 227718039650203ULL;
 static size_t ZSTD_hash6(U64 u, U32 h) { return (size_t)(((u  << (64-48)) * prime6bytes) >> (64-h)) ; }
 static size_t ZSTD_hash6Ptr(const void* p, U32 h) { return ZSTD_hash6(MEM_readLE64(p), h); }
 
 static const U64 prime7bytes = 58295818150454627ULL;
 static size_t ZSTD_hash7(U64 u, U32 h) { return (size_t)(((u  << (64-56)) * prime7bytes) >> (64-h)) ; }
 static size_t ZSTD_hash7Ptr(const void* p, U32 h) { return ZSTD_hash7(MEM_readLE64(p), h); }
 
 static const U64 prime8bytes = 0xCF1BBCDCB7A56463ULL;
 static size_t ZSTD_hash8(U64 u, U32 h) { return (size_t)(((u) * prime8bytes) >> (64-h)) ; }
 static size_t ZSTD_hash8Ptr(const void* p, U32 h) { return ZSTD_hash8(MEM_readLE64(p), h); }
 
 MEM_STATIC size_t ZSTD_hashPtr(const void* p, U32 hBits, U32 mls)
 {
     switch(mls)
     {
     default:
     case 4: return ZSTD_hash4Ptr(p, hBits);
     case 5: return ZSTD_hash5Ptr(p, hBits);
     case 6: return ZSTD_hash6Ptr(p, hBits);
     case 7: return ZSTD_hash7Ptr(p, hBits);
     case 8: return ZSTD_hash8Ptr(p, hBits);
     }
 }
 
 /** ZSTD_ipow() :
  * Return base^exponent.
  */
 static U64 ZSTD_ipow(U64 base, U64 exponent)
 {
     U64 power = 1;
     while (exponent) {
       if (exponent & 1) power *= base;
       exponent >>= 1;
       base *= base;
     }
     return power;
 }
 
 #define ZSTD_ROLL_HASH_CHAR_OFFSET 10
 
 /** ZSTD_rollingHash_append() :
  * Add the buffer to the hash value.
  */
 static U64 ZSTD_rollingHash_append(U64 hash, void const* buf, size_t size)
 {
     BYTE const* istart = (BYTE const*)buf;
     size_t pos;
     for (pos = 0; pos < size; ++pos) {
         hash *= prime8bytes;
         hash += istart[pos] + ZSTD_ROLL_HASH_CHAR_OFFSET;
     }
     return hash;
 }
 
 /** ZSTD_rollingHash_compute() :
  * Compute the rolling hash value of the buffer.
  */
 MEM_STATIC U64 ZSTD_rollingHash_compute(void const* buf, size_t size)
 {
     return ZSTD_rollingHash_append(0, buf, size);
 }
 
 /** ZSTD_rollingHash_primePower() :
  * Compute the primePower to be passed to ZSTD_rollingHash_rotate() for a hash
  * over a window of length bytes.
  */
 MEM_STATIC U64 ZSTD_rollingHash_primePower(U32 length)
 {
     return ZSTD_ipow(prime8bytes, length - 1);
 }
 
 /** ZSTD_rollingHash_rotate() :
  * Rotate the rolling hash by one byte.
  */
 MEM_STATIC U64 ZSTD_rollingHash_rotate(U64 hash, BYTE toRemove, BYTE toAdd, U64 primePower)
 {
     hash -= (toRemove + ZSTD_ROLL_HASH_CHAR_OFFSET) * primePower;
     hash *= prime8bytes;
     hash += toAdd + ZSTD_ROLL_HASH_CHAR_OFFSET;
     return hash;
 }
 
 /*-*************************************
 *  Round buffer management
 ***************************************/
 #if (ZSTD_WINDOWLOG_MAX_64 > 31)
 # error "ZSTD_WINDOWLOG_MAX is too large : would overflow ZSTD_CURRENT_MAX"
 #endif
 /* Max current allowed */
 #define ZSTD_CURRENT_MAX ((3U << 29) + (1U << ZSTD_WINDOWLOG_MAX))
 /* Maximum chunk size before overflow correction needs to be called again */
 #define ZSTD_CHUNKSIZE_MAX                                                     \
     ( ((U32)-1)                  /* Maximum ending current index */            \
     - ZSTD_CURRENT_MAX)          /* Maximum beginning lowLimit */
 
 /**
  * ZSTD_window_clear():
  * Clears the window containing the history by simply setting it to empty.
  */
 MEM_STATIC void ZSTD_window_clear(ZSTD_window_t* window)
 {
     size_t const endT = (size_t)(window->nextSrc - window->base);
     U32 const end = (U32)endT;
 
     window->lowLimit = end;
     window->dictLimit = end;
 }
 
 /**
  * ZSTD_window_hasExtDict():
  * Returns non-zero if the window has a non-empty extDict.
  */
 MEM_STATIC U32 ZSTD_window_hasExtDict(ZSTD_window_t const window)
 {
     return window.lowLimit < window.dictLimit;
 }
 
 /**
  * ZSTD_matchState_dictMode():
  * Inspects the provided matchState and figures out what dictMode should be
  * passed to the compressor.
  */
 MEM_STATIC ZSTD_dictMode_e ZSTD_matchState_dictMode(const ZSTD_matchState_t *ms)
 {
     return ZSTD_window_hasExtDict(ms->window) ?
         ZSTD_extDict :
         ms->dictMatchState != NULL ?
             ZSTD_dictMatchState :
             ZSTD_noDict;
 }
 
 /**
  * ZSTD_window_needOverflowCorrection():
  * Returns non-zero if the indices are getting too large and need overflow
  * protection.
  */
 MEM_STATIC U32 ZSTD_window_needOverflowCorrection(ZSTD_window_t const window,
                                                   void const* srcEnd)
 {
     U32 const current = (U32)((BYTE const*)srcEnd - window.base);
     return current > ZSTD_CURRENT_MAX;
 }
 
 /**
  * ZSTD_window_correctOverflow():
  * Reduces the indices to protect from index overflow.
  * Returns the correction made to the indices, which must be applied to every
  * stored index.
  *
  * The least significant cycleLog bits of the indices must remain the same,
  * which may be 0. Every index up to maxDist in the past must be valid.
  * NOTE: (maxDist & cycleMask) must be zero.
  */
 MEM_STATIC U32 ZSTD_window_correctOverflow(ZSTD_window_t* window, U32 cycleLog,
                                            U32 maxDist, void const* src)
 {
     /* preemptive overflow correction:
      * 1. correction is large enough:
      *    lowLimit > (3<<29) ==> current > 3<<29 + 1< (3<<29 + 1< (3<<29) - (1< (3<<29) - (1<<30)             (NOTE: chainLog <= 30)
      *    > 1<<29
      *
      * 2. (ip+ZSTD_CHUNKSIZE_MAX - cctx->base) doesn't overflow:
      *    After correction, current is less than (1<base < 1<<32.
      * 3. (cctx->lowLimit + 1< 3<<29 + 1<base);
     U32 const newCurrent = (current & cycleMask) + maxDist;
     U32 const correction = current - newCurrent;
     assert((maxDist & cycleMask) == 0);
     assert(current > newCurrent);
     /* Loose bound, should be around 1<<29 (see above) */
     assert(correction > 1<<28);
 
     window->base += correction;
     window->dictBase += correction;
     window->lowLimit -= correction;
     window->dictLimit -= correction;
 
     DEBUGLOG(4, "Correction of 0x%x bytes to lowLimit=0x%x", correction,
              window->lowLimit);
     return correction;
 }
 
 /**
  * ZSTD_window_enforceMaxDist():
  * Updates lowLimit so that:
  *    (srcEnd - base) - lowLimit == maxDist + loadedDictEnd
  *
  * It ensures index is valid as long as index >= lowLimit.
  * This must be called before a block compression call.
  *
  * loadedDictEnd is only defined if a dictionary is in use for current compression.
  * As the name implies, loadedDictEnd represents the index at end of dictionary.
  * The value lies within context's referential, it can be directly compared to blockEndIdx.
  *
  * If loadedDictEndPtr is NULL, no dictionary is in use, and we use loadedDictEnd == 0.
  * If loadedDictEndPtr is not NULL, we set it to zero after updating lowLimit.
  * This is because dictionaries are allowed to be referenced fully
  * as long as the last byte of the dictionary is in the window.
  * Once input has progressed beyond window size, dictionary cannot be referenced anymore.
  *
  * In normal dict mode, the dictionary lies between lowLimit and dictLimit.
  * In dictMatchState mode, lowLimit and dictLimit are the same,
  * and the dictionary is below them.
  * forceWindow and dictMatchState are therefore incompatible.
  */
 MEM_STATIC void
 ZSTD_window_enforceMaxDist(ZSTD_window_t* window,
                      const void* blockEnd,
                            U32   maxDist,
                            U32*  loadedDictEndPtr,
                      const ZSTD_matchState_t** dictMatchStatePtr)
 {
     U32 const blockEndIdx = (U32)((BYTE const*)blockEnd - window->base);
     U32 const loadedDictEnd = (loadedDictEndPtr != NULL) ? *loadedDictEndPtr : 0;
     DEBUGLOG(5, "ZSTD_window_enforceMaxDist: blockEndIdx=%u, maxDist=%u, loadedDictEnd=%u",
                 (unsigned)blockEndIdx, (unsigned)maxDist, (unsigned)loadedDictEnd);
 
     /* - When there is no dictionary : loadedDictEnd == 0.
          In which case, the test (blockEndIdx > maxDist) is merely to avoid
          overflowing next operation `newLowLimit = blockEndIdx - maxDist`.
        - When there is a standard dictionary :
          Index referential is copied from the dictionary,
          which means it starts from 0.
          In which case, loadedDictEnd == dictSize,
          and it makes sense to compare `blockEndIdx > maxDist + dictSize`
          since `blockEndIdx` also starts from zero.
        - When there is an attached dictionary :
          loadedDictEnd is expressed within the referential of the context,
          so it can be directly compared against blockEndIdx.
     */
     if (blockEndIdx > maxDist + loadedDictEnd) {
         U32 const newLowLimit = blockEndIdx - maxDist;
         if (window->lowLimit < newLowLimit) window->lowLimit = newLowLimit;
         if (window->dictLimit < window->lowLimit) {
             DEBUGLOG(5, "Update dictLimit to match lowLimit, from %u to %u",
                         (unsigned)window->dictLimit, (unsigned)window->lowLimit);
             window->dictLimit = window->lowLimit;
         }
         /* On reaching window size, dictionaries are invalidated */
         if (loadedDictEndPtr) *loadedDictEndPtr = 0;
         if (dictMatchStatePtr) *dictMatchStatePtr = NULL;
     }
 }
 
 /* Similar to ZSTD_window_enforceMaxDist(),
  * but only invalidates dictionary
- * when input progresses beyond window size. */
+ * when input progresses beyond window size.
+ * assumption : loadedDictEndPtr and dictMatchStatePtr are valid (non NULL)
+ *              loadedDictEnd uses same referential as window->base
+ *              maxDist is the window size */
 MEM_STATIC void
-ZSTD_checkDictValidity(ZSTD_window_t* window,
+ZSTD_checkDictValidity(const ZSTD_window_t* window,
                        const void* blockEnd,
                              U32   maxDist,
                              U32*  loadedDictEndPtr,
                        const ZSTD_matchState_t** dictMatchStatePtr)
 {
-    U32 const blockEndIdx = (U32)((BYTE const*)blockEnd - window->base);
-    U32 const loadedDictEnd = (loadedDictEndPtr != NULL) ? *loadedDictEndPtr : 0;
-    DEBUGLOG(5, "ZSTD_checkDictValidity: blockEndIdx=%u, maxDist=%u, loadedDictEnd=%u",
-                (unsigned)blockEndIdx, (unsigned)maxDist, (unsigned)loadedDictEnd);
+    assert(loadedDictEndPtr != NULL);
+    assert(dictMatchStatePtr != NULL);
+    {   U32 const blockEndIdx = (U32)((BYTE const*)blockEnd - window->base);
+        U32 const loadedDictEnd = *loadedDictEndPtr;
+        DEBUGLOG(5, "ZSTD_checkDictValidity: blockEndIdx=%u, maxDist=%u, loadedDictEnd=%u",
+                    (unsigned)blockEndIdx, (unsigned)maxDist, (unsigned)loadedDictEnd);
+        assert(blockEndIdx >= loadedDictEnd);
 
-    if (loadedDictEnd && (blockEndIdx > maxDist + loadedDictEnd)) {
-        /* On reaching window size, dictionaries are invalidated */
-        if (loadedDictEndPtr) *loadedDictEndPtr = 0;
-        if (dictMatchStatePtr) *dictMatchStatePtr = NULL;
-    }
+        if (blockEndIdx > loadedDictEnd + maxDist) {
+            /* On reaching window size, dictionaries are invalidated.
+             * For simplification, if window size is reached anywhere within next block,
+             * the dictionary is invalidated for the full block.
+             */
+            DEBUGLOG(6, "invalidating dictionary for current block (distance > windowSize)");
+            *loadedDictEndPtr = 0;
+            *dictMatchStatePtr = NULL;
+        } else {
+            if (*loadedDictEndPtr != 0) {
+                DEBUGLOG(6, "dictionary considered valid for current block");
+    }   }   }
 }
 
 /**
  * ZSTD_window_update():
  * Updates the window by appending [src, src + srcSize) to the window.
  * If it is not contiguous, the current prefix becomes the extDict, and we
  * forget about the extDict. Handles overlap of the prefix and extDict.
  * Returns non-zero if the segment is contiguous.
  */
 MEM_STATIC U32 ZSTD_window_update(ZSTD_window_t* window,
                                   void const* src, size_t srcSize)
 {
     BYTE const* const ip = (BYTE const*)src;
     U32 contiguous = 1;
     DEBUGLOG(5, "ZSTD_window_update");
     /* Check if blocks follow each other */
     if (src != window->nextSrc) {
         /* not contiguous */
         size_t const distanceFromBase = (size_t)(window->nextSrc - window->base);
         DEBUGLOG(5, "Non contiguous blocks, new segment starts at %u", window->dictLimit);
         window->lowLimit = window->dictLimit;
         assert(distanceFromBase == (size_t)(U32)distanceFromBase);  /* should never overflow */
         window->dictLimit = (U32)distanceFromBase;
         window->dictBase = window->base;
         window->base = ip - distanceFromBase;
         // ms->nextToUpdate = window->dictLimit;
         if (window->dictLimit - window->lowLimit < HASH_READ_SIZE) window->lowLimit = window->dictLimit;   /* too small extDict */
         contiguous = 0;
     }
     window->nextSrc = ip + srcSize;
     /* if input and dictionary overlap : reduce dictionary (area presumed modified by input) */
     if ( (ip+srcSize > window->dictBase + window->lowLimit)
        & (ip < window->dictBase + window->dictLimit)) {
         ptrdiff_t const highInputIdx = (ip + srcSize) - window->dictBase;
         U32 const lowLimitMax = (highInputIdx > (ptrdiff_t)window->dictLimit) ? window->dictLimit : (U32)highInputIdx;
         window->lowLimit = lowLimitMax;
         DEBUGLOG(5, "Overlapping extDict and input : new lowLimit = %u", window->lowLimit);
     }
     return contiguous;
 }
 
+MEM_STATIC U32 ZSTD_getLowestMatchIndex(const ZSTD_matchState_t* ms, U32 current, unsigned windowLog)
+{
+    U32    const maxDistance = 1U << windowLog;
+    U32    const lowestValid = ms->window.lowLimit;
+    U32    const withinWindow = (current - lowestValid > maxDistance) ? current - maxDistance : lowestValid;
+    U32    const isDictionary = (ms->loadedDictEnd != 0);
+    U32    const matchLowest = isDictionary ? lowestValid : withinWindow;
+    return matchLowest;
+}
 
+
+
 /* debug functions */
 #if (DEBUGLEVEL>=2)
 
 MEM_STATIC double ZSTD_fWeight(U32 rawStat)
 {
     U32 const fp_accuracy = 8;
     U32 const fp_multiplier = (1 << fp_accuracy);
     U32 const newStat = rawStat + 1;
     U32 const hb = ZSTD_highbit32(newStat);
     U32 const BWeight = hb * fp_multiplier;
     U32 const FWeight = (newStat << fp_accuracy) >> hb;
     U32 const weight = BWeight + FWeight;
     assert(hb + fp_accuracy < 31);
     return (double)weight / fp_multiplier;
 }
 
 /* display a table content,
  * listing each element, its frequency, and its predicted bit cost */
 MEM_STATIC void ZSTD_debugTable(const U32* table, U32 max)
 {
     unsigned u, sum;
     for (u=0, sum=0; u<=max; u++) sum += table[u];
     DEBUGLOG(2, "total nb elts: %u", sum);
     for (u=0; u<=max; u++) {
         DEBUGLOG(2, "%2u: %5u  (%.2f)",
                 u, table[u], ZSTD_fWeight(sum) - ZSTD_fWeight(table[u]) );
     }
 }
 
 #endif
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 
 /* ==============================================================
  * Private declarations
  * These prototypes shall only be called from within lib/compress
  * ============================================================== */
 
 /* ZSTD_getCParamsFromCCtxParams() :
  * cParams are built depending on compressionLevel, src size hints,
  * LDM and manually set compression parameters.
  */
 ZSTD_compressionParameters ZSTD_getCParamsFromCCtxParams(
         const ZSTD_CCtx_params* CCtxParams, U64 srcSizeHint, size_t dictSize);
 
 /*! ZSTD_initCStream_internal() :
  *  Private use only. Init streaming operation.
  *  expects params to be valid.
  *  must receive dict, or cdict, or none, but not both.
  *  @return : 0, or an error code */
 size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
                      const void* dict, size_t dictSize,
                      const ZSTD_CDict* cdict,
-                     ZSTD_CCtx_params  params, unsigned long long pledgedSrcSize);
+                     const ZSTD_CCtx_params* params, unsigned long long pledgedSrcSize);
 
 void ZSTD_resetSeqStore(seqStore_t* ssPtr);
 
 /*! ZSTD_getCParamsFromCDict() :
  *  as the name implies */
 ZSTD_compressionParameters ZSTD_getCParamsFromCDict(const ZSTD_CDict* cdict);
 
 /* ZSTD_compressBegin_advanced_internal() :
  * Private use only. To be called from zstdmt_compress.c. */
 size_t ZSTD_compressBegin_advanced_internal(ZSTD_CCtx* cctx,
                                     const void* dict, size_t dictSize,
                                     ZSTD_dictContentType_e dictContentType,
                                     ZSTD_dictTableLoadMethod_e dtlm,
                                     const ZSTD_CDict* cdict,
-                                    ZSTD_CCtx_params params,
+                                    const ZSTD_CCtx_params* params,
                                     unsigned long long pledgedSrcSize);
 
 /* ZSTD_compress_advanced_internal() :
  * Private use only. To be called from zstdmt_compress.c. */
 size_t ZSTD_compress_advanced_internal(ZSTD_CCtx* cctx,
                                        void* dst, size_t dstCapacity,
                                  const void* src, size_t srcSize,
                                  const void* dict,size_t dictSize,
-                                 ZSTD_CCtx_params params);
+                                 const ZSTD_CCtx_params* params);
 
 
 /* ZSTD_writeLastEmptyBlock() :
  * output an empty Block with end-of-frame mark to complete a frame
  * @return : size of data written into `dst` (== ZSTD_blockHeaderSize (defined in zstd_internal.h))
  *           or an error code if `dstCapacity` is too small (31) + (srcSize>4095);
 
     RETURN_ERROR_IF(srcSize + flSize > dstCapacity, dstSize_tooSmall);
 
     switch(flSize)
     {
         case 1: /* 2 - 1 - 5 */
             ostart[0] = (BYTE)((U32)set_basic + (srcSize<<3));
             break;
         case 2: /* 2 - 2 - 12 */
             MEM_writeLE16(ostart, (U16)((U32)set_basic + (1<<2) + (srcSize<<4)));
             break;
         case 3: /* 2 - 2 - 20 */
             MEM_writeLE32(ostart, (U32)((U32)set_basic + (3<<2) + (srcSize<<4)));
             break;
         default:   /* not necessary : flSize is {1,2,3} */
             assert(0);
     }
 
     memcpy(ostart + flSize, src, srcSize);
     return srcSize + flSize;
 }
 
 size_t ZSTD_compressRleLiteralsBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     BYTE* const ostart = (BYTE* const)dst;
     U32   const flSize = 1 + (srcSize>31) + (srcSize>4095);
 
     (void)dstCapacity;  /* dstCapacity already guaranteed to be >=4, hence large enough */
 
     switch(flSize)
     {
         case 1: /* 2 - 1 - 5 */
             ostart[0] = (BYTE)((U32)set_rle + (srcSize<<3));
             break;
         case 2: /* 2 - 2 - 12 */
             MEM_writeLE16(ostart, (U16)((U32)set_rle + (1<<2) + (srcSize<<4)));
             break;
         case 3: /* 2 - 2 - 20 */
             MEM_writeLE32(ostart, (U32)((U32)set_rle + (3<<2) + (srcSize<<4)));
             break;
         default:   /* not necessary : flSize is {1,2,3} */
             assert(0);
     }
 
     ostart[flSize] = *(const BYTE*)src;
     return flSize+1;
 }
 
 size_t ZSTD_compressLiterals (ZSTD_hufCTables_t const* prevHuf,
                               ZSTD_hufCTables_t* nextHuf,
                               ZSTD_strategy strategy, int disableLiteralCompression,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize,
-                              void* workspace, size_t wkspSize,
+                              void* entropyWorkspace, size_t entropyWorkspaceSize,
                         const int bmi2)
 {
     size_t const minGain = ZSTD_minGain(srcSize, strategy);
     size_t const lhSize = 3 + (srcSize >= 1 KB) + (srcSize >= 16 KB);
     BYTE*  const ostart = (BYTE*)dst;
     U32 singleStream = srcSize < 256;
     symbolEncodingType_e hType = set_compressed;
     size_t cLitSize;
 
     DEBUGLOG(5,"ZSTD_compressLiterals (disableLiteralCompression=%i)",
                 disableLiteralCompression);
 
     /* Prepare nextEntropy assuming reusing the existing table */
     memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
 
     if (disableLiteralCompression)
         return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
 
     /* small ? don't even attempt compression (speed opt) */
 #   define COMPRESS_LITERALS_SIZE_MIN 63
     {   size_t const minLitSize = (prevHuf->repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN;
         if (srcSize <= minLitSize) return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
     }
 
     RETURN_ERROR_IF(dstCapacity < lhSize+1, dstSize_tooSmall, "not enough space for compression");
     {   HUF_repeat repeat = prevHuf->repeatMode;
         int const preferRepeat = strategy < ZSTD_lazy ? srcSize <= 1024 : 0;
         if (repeat == HUF_repeat_valid && lhSize == 3) singleStream = 1;
-        cLitSize = singleStream ? HUF_compress1X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11,
-                                      workspace, wkspSize, (HUF_CElt*)nextHuf->CTable, &repeat, preferRepeat, bmi2)
-                                : HUF_compress4X_repeat(ostart+lhSize, dstCapacity-lhSize, src, srcSize, 255, 11,
-                                      workspace, wkspSize, (HUF_CElt*)nextHuf->CTable, &repeat, preferRepeat, bmi2);
+        cLitSize = singleStream ?
+            HUF_compress1X_repeat(
+                ostart+lhSize, dstCapacity-lhSize, src, srcSize,
+                255, 11, entropyWorkspace, entropyWorkspaceSize,
+                (HUF_CElt*)nextHuf->CTable, &repeat, preferRepeat, bmi2) :
+            HUF_compress4X_repeat(
+                ostart+lhSize, dstCapacity-lhSize, src, srcSize,
+                255, 11, entropyWorkspace, entropyWorkspaceSize,
+                (HUF_CElt*)nextHuf->CTable, &repeat, preferRepeat, bmi2);
         if (repeat != HUF_repeat_none) {
             /* reused the existing table */
             hType = set_repeat;
         }
     }
 
     if ((cLitSize==0) | (cLitSize >= srcSize - minGain) | ERR_isError(cLitSize)) {
         memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
         return ZSTD_noCompressLiterals(dst, dstCapacity, src, srcSize);
     }
     if (cLitSize==1) {
         memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
         return ZSTD_compressRleLiteralsBlock(dst, dstCapacity, src, srcSize);
     }
 
     if (hType == set_compressed) {
         /* using a newly constructed table */
         nextHuf->repeatMode = HUF_repeat_check;
     }
 
     /* Build header */
     switch(lhSize)
     {
     case 3: /* 2 - 2 - 10 - 10 */
         {   U32 const lhc = hType + ((!singleStream) << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<14);
             MEM_writeLE24(ostart, lhc);
             break;
         }
     case 4: /* 2 - 2 - 14 - 14 */
         {   U32 const lhc = hType + (2 << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<18);
             MEM_writeLE32(ostart, lhc);
             break;
         }
     case 5: /* 2 - 2 - 18 - 18 */
         {   U32 const lhc = hType + (3 << 2) + ((U32)srcSize<<4) + ((U32)cLitSize<<22);
             MEM_writeLE32(ostart, lhc);
             ostart[4] = (BYTE)(cLitSize >> 10);
             break;
         }
     default:  /* not possible : lhSize is {3,4,5} */
         assert(0);
     }
     return lhSize+cLitSize;
 }
Index: head/sys/contrib/zstd/lib/compress/zstd_compress_literals.h
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_compress_literals.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_compress_literals.h	(revision 354777)
@@ -1,29 +1,29 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_COMPRESS_LITERALS_H
 #define ZSTD_COMPRESS_LITERALS_H
 
 #include "zstd_compress_internal.h" /* ZSTD_hufCTables_t, ZSTD_minGain() */
 
 
 size_t ZSTD_noCompressLiterals (void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 
 size_t ZSTD_compressRleLiteralsBlock (void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 
 size_t ZSTD_compressLiterals (ZSTD_hufCTables_t const* prevHuf,
                               ZSTD_hufCTables_t* nextHuf,
                               ZSTD_strategy strategy, int disableLiteralCompression,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize,
-                              void* workspace, size_t wkspSize,
+                              void* entropyWorkspace, size_t entropyWorkspaceSize,
                         const int bmi2);
 
 #endif /* ZSTD_COMPRESS_LITERALS_H */
Index: head/sys/contrib/zstd/lib/compress/zstd_compress_sequences.c
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_compress_sequences.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_compress_sequences.c	(revision 354777)
@@ -1,415 +1,415 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
  /*-*************************************
  *  Dependencies
  ***************************************/
 #include "zstd_compress_sequences.h"
 
 /**
  * -log2(x / 256) lookup table for x in [0, 256).
  * If x == 0: Return 0
  * Else: Return floor(-log2(x / 256) * 256)
  */
 static unsigned const kInverseProbabilityLog256[256] = {
     0,    2048, 1792, 1642, 1536, 1453, 1386, 1329, 1280, 1236, 1197, 1162,
     1130, 1100, 1073, 1047, 1024, 1001, 980,  960,  941,  923,  906,  889,
     874,  859,  844,  830,  817,  804,  791,  779,  768,  756,  745,  734,
     724,  714,  704,  694,  685,  676,  667,  658,  650,  642,  633,  626,
     618,  610,  603,  595,  588,  581,  574,  567,  561,  554,  548,  542,
     535,  529,  523,  517,  512,  506,  500,  495,  489,  484,  478,  473,
     468,  463,  458,  453,  448,  443,  438,  434,  429,  424,  420,  415,
     411,  407,  402,  398,  394,  390,  386,  382,  377,  373,  370,  366,
     362,  358,  354,  350,  347,  343,  339,  336,  332,  329,  325,  322,
     318,  315,  311,  308,  305,  302,  298,  295,  292,  289,  286,  282,
     279,  276,  273,  270,  267,  264,  261,  258,  256,  253,  250,  247,
     244,  241,  239,  236,  233,  230,  228,  225,  222,  220,  217,  215,
     212,  209,  207,  204,  202,  199,  197,  194,  192,  190,  187,  185,
     182,  180,  178,  175,  173,  171,  168,  166,  164,  162,  159,  157,
     155,  153,  151,  149,  146,  144,  142,  140,  138,  136,  134,  132,
     130,  128,  126,  123,  121,  119,  117,  115,  114,  112,  110,  108,
     106,  104,  102,  100,  98,   96,   94,   93,   91,   89,   87,   85,
     83,   82,   80,   78,   76,   74,   73,   71,   69,   67,   66,   64,
     62,   61,   59,   57,   55,   54,   52,   50,   49,   47,   46,   44,
     42,   41,   39,   37,   36,   34,   33,   31,   30,   28,   26,   25,
     23,   22,   20,   19,   17,   16,   14,   13,   11,   10,   8,    7,
     5,    4,    2,    1,
 };
 
 static unsigned ZSTD_getFSEMaxSymbolValue(FSE_CTable const* ctable) {
   void const* ptr = ctable;
   U16 const* u16ptr = (U16 const*)ptr;
   U32 const maxSymbolValue = MEM_read16(u16ptr + 1);
   return maxSymbolValue;
 }
 
 /**
  * Returns the cost in bytes of encoding the normalized count header.
  * Returns an error if any of the helper functions return an error.
  */
 static size_t ZSTD_NCountCost(unsigned const* count, unsigned const max,
                               size_t const nbSeq, unsigned const FSELog)
 {
     BYTE wksp[FSE_NCOUNTBOUND];
     S16 norm[MaxSeq + 1];
     const U32 tableLog = FSE_optimalTableLog(FSELog, nbSeq, max);
     FORWARD_IF_ERROR(FSE_normalizeCount(norm, tableLog, count, nbSeq, max));
     return FSE_writeNCount(wksp, sizeof(wksp), norm, max, tableLog);
 }
 
 /**
  * Returns the cost in bits of encoding the distribution described by count
  * using the entropy bound.
  */
 static size_t ZSTD_entropyCost(unsigned const* count, unsigned const max, size_t const total)
 {
     unsigned cost = 0;
     unsigned s;
     for (s = 0; s <= max; ++s) {
         unsigned norm = (unsigned)((256 * count[s]) / total);
         if (count[s] != 0 && norm == 0)
             norm = 1;
         assert(count[s] < total);
         cost += count[s] * kInverseProbabilityLog256[norm];
     }
     return cost >> 8;
 }
 
 /**
  * Returns the cost in bits of encoding the distribution in count using ctable.
  * Returns an error if ctable cannot represent all the symbols in count.
  */
 static size_t ZSTD_fseBitCost(
     FSE_CTable const* ctable,
     unsigned const* count,
     unsigned const max)
 {
     unsigned const kAccuracyLog = 8;
     size_t cost = 0;
     unsigned s;
     FSE_CState_t cstate;
     FSE_initCState(&cstate, ctable);
     RETURN_ERROR_IF(ZSTD_getFSEMaxSymbolValue(ctable) < max, GENERIC,
                     "Repeat FSE_CTable has maxSymbolValue %u < %u",
                     ZSTD_getFSEMaxSymbolValue(ctable), max);
     for (s = 0; s <= max; ++s) {
         unsigned const tableLog = cstate.stateLog;
         unsigned const badCost = (tableLog + 1) << kAccuracyLog;
         unsigned const bitCost = FSE_bitCost(cstate.symbolTT, tableLog, s, kAccuracyLog);
         if (count[s] == 0)
             continue;
         RETURN_ERROR_IF(bitCost >= badCost, GENERIC,
                         "Repeat FSE_CTable has Prob[%u] == 0", s);
         cost += count[s] * bitCost;
     }
     return cost >> kAccuracyLog;
 }
 
 /**
  * Returns the cost in bits of encoding the distribution in count using the
  * table described by norm. The max symbol support by norm is assumed >= max.
  * norm must be valid for every symbol with non-zero probability in count.
  */
 static size_t ZSTD_crossEntropyCost(short const* norm, unsigned accuracyLog,
                                     unsigned const* count, unsigned const max)
 {
     unsigned const shift = 8 - accuracyLog;
     size_t cost = 0;
     unsigned s;
     assert(accuracyLog <= 8);
     for (s = 0; s <= max; ++s) {
         unsigned const normAcc = norm[s] != -1 ? norm[s] : 1;
         unsigned const norm256 = normAcc << shift;
         assert(norm256 > 0);
         assert(norm256 < 256);
         cost += count[s] * kInverseProbabilityLog256[norm256];
     }
     return cost >> 8;
 }
 
 symbolEncodingType_e
 ZSTD_selectEncodingType(
         FSE_repeat* repeatMode, unsigned const* count, unsigned const max,
         size_t const mostFrequent, size_t nbSeq, unsigned const FSELog,
         FSE_CTable const* prevCTable,
         short const* defaultNorm, U32 defaultNormLog,
         ZSTD_defaultPolicy_e const isDefaultAllowed,
         ZSTD_strategy const strategy)
 {
     ZSTD_STATIC_ASSERT(ZSTD_defaultDisallowed == 0 && ZSTD_defaultAllowed != 0);
     if (mostFrequent == nbSeq) {
         *repeatMode = FSE_repeat_none;
         if (isDefaultAllowed && nbSeq <= 2) {
             /* Prefer set_basic over set_rle when there are 2 or less symbols,
              * since RLE uses 1 byte, but set_basic uses 5-6 bits per symbol.
              * If basic encoding isn't possible, always choose RLE.
              */
             DEBUGLOG(5, "Selected set_basic");
             return set_basic;
         }
         DEBUGLOG(5, "Selected set_rle");
         return set_rle;
     }
     if (strategy < ZSTD_lazy) {
         if (isDefaultAllowed) {
             size_t const staticFse_nbSeq_max = 1000;
             size_t const mult = 10 - strategy;
             size_t const baseLog = 3;
             size_t const dynamicFse_nbSeq_min = (((size_t)1 << defaultNormLog) * mult) >> baseLog;  /* 28-36 for offset, 56-72 for lengths */
             assert(defaultNormLog >= 5 && defaultNormLog <= 6);  /* xx_DEFAULTNORMLOG */
             assert(mult <= 9 && mult >= 7);
             if ( (*repeatMode == FSE_repeat_valid)
               && (nbSeq < staticFse_nbSeq_max) ) {
                 DEBUGLOG(5, "Selected set_repeat");
                 return set_repeat;
             }
             if ( (nbSeq < dynamicFse_nbSeq_min)
               || (mostFrequent < (nbSeq >> (defaultNormLog-1))) ) {
                 DEBUGLOG(5, "Selected set_basic");
                 /* The format allows default tables to be repeated, but it isn't useful.
                  * When using simple heuristics to select encoding type, we don't want
                  * to confuse these tables with dictionaries. When running more careful
                  * analysis, we don't need to waste time checking both repeating tables
                  * and default tables.
                  */
                 *repeatMode = FSE_repeat_none;
                 return set_basic;
             }
         }
     } else {
         size_t const basicCost = isDefaultAllowed ? ZSTD_crossEntropyCost(defaultNorm, defaultNormLog, count, max) : ERROR(GENERIC);
         size_t const repeatCost = *repeatMode != FSE_repeat_none ? ZSTD_fseBitCost(prevCTable, count, max) : ERROR(GENERIC);
         size_t const NCountCost = ZSTD_NCountCost(count, max, nbSeq, FSELog);
         size_t const compressedCost = (NCountCost << 3) + ZSTD_entropyCost(count, max, nbSeq);
 
         if (isDefaultAllowed) {
             assert(!ZSTD_isError(basicCost));
             assert(!(*repeatMode == FSE_repeat_valid && ZSTD_isError(repeatCost)));
         }
         assert(!ZSTD_isError(NCountCost));
         assert(compressedCost < ERROR(maxCode));
         DEBUGLOG(5, "Estimated bit costs: basic=%u\trepeat=%u\tcompressed=%u",
                     (unsigned)basicCost, (unsigned)repeatCost, (unsigned)compressedCost);
         if (basicCost <= repeatCost && basicCost <= compressedCost) {
             DEBUGLOG(5, "Selected set_basic");
             assert(isDefaultAllowed);
             *repeatMode = FSE_repeat_none;
             return set_basic;
         }
         if (repeatCost <= compressedCost) {
             DEBUGLOG(5, "Selected set_repeat");
             assert(!ZSTD_isError(repeatCost));
             return set_repeat;
         }
         assert(compressedCost < basicCost && compressedCost < repeatCost);
     }
     DEBUGLOG(5, "Selected set_compressed");
     *repeatMode = FSE_repeat_check;
     return set_compressed;
 }
 
 size_t
 ZSTD_buildCTable(void* dst, size_t dstCapacity,
                 FSE_CTable* nextCTable, U32 FSELog, symbolEncodingType_e type,
                 unsigned* count, U32 max,
                 const BYTE* codeTable, size_t nbSeq,
                 const S16* defaultNorm, U32 defaultNormLog, U32 defaultMax,
                 const FSE_CTable* prevCTable, size_t prevCTableSize,
-                void* workspace, size_t workspaceSize)
+                void* entropyWorkspace, size_t entropyWorkspaceSize)
 {
     BYTE* op = (BYTE*)dst;
     const BYTE* const oend = op + dstCapacity;
     DEBUGLOG(6, "ZSTD_buildCTable (dstCapacity=%u)", (unsigned)dstCapacity);
 
     switch (type) {
     case set_rle:
         FORWARD_IF_ERROR(FSE_buildCTable_rle(nextCTable, (BYTE)max));
         RETURN_ERROR_IF(dstCapacity==0, dstSize_tooSmall);
         *op = codeTable[0];
         return 1;
     case set_repeat:
         memcpy(nextCTable, prevCTable, prevCTableSize);
         return 0;
     case set_basic:
-        FORWARD_IF_ERROR(FSE_buildCTable_wksp(nextCTable, defaultNorm, defaultMax, defaultNormLog, workspace, workspaceSize));  /* note : could be pre-calculated */
+        FORWARD_IF_ERROR(FSE_buildCTable_wksp(nextCTable, defaultNorm, defaultMax, defaultNormLog, entropyWorkspace, entropyWorkspaceSize));  /* note : could be pre-calculated */
         return 0;
     case set_compressed: {
         S16 norm[MaxSeq + 1];
         size_t nbSeq_1 = nbSeq;
         const U32 tableLog = FSE_optimalTableLog(FSELog, nbSeq, max);
         if (count[codeTable[nbSeq-1]] > 1) {
             count[codeTable[nbSeq-1]]--;
             nbSeq_1--;
         }
         assert(nbSeq_1 > 1);
         FORWARD_IF_ERROR(FSE_normalizeCount(norm, tableLog, count, nbSeq_1, max));
         {   size_t const NCountSize = FSE_writeNCount(op, oend - op, norm, max, tableLog);   /* overflow protected */
             FORWARD_IF_ERROR(NCountSize);
-            FORWARD_IF_ERROR(FSE_buildCTable_wksp(nextCTable, norm, max, tableLog, workspace, workspaceSize));
+            FORWARD_IF_ERROR(FSE_buildCTable_wksp(nextCTable, norm, max, tableLog, entropyWorkspace, entropyWorkspaceSize));
             return NCountSize;
         }
     }
     default: assert(0); RETURN_ERROR(GENERIC);
     }
 }
 
 FORCE_INLINE_TEMPLATE size_t
 ZSTD_encodeSequences_body(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets)
 {
     BIT_CStream_t blockStream;
     FSE_CState_t  stateMatchLength;
     FSE_CState_t  stateOffsetBits;
     FSE_CState_t  stateLitLength;
 
     RETURN_ERROR_IF(
         ERR_isError(BIT_initCStream(&blockStream, dst, dstCapacity)),
         dstSize_tooSmall, "not enough space remaining");
     DEBUGLOG(6, "available space for bitstream : %i  (dstCapacity=%u)",
                 (int)(blockStream.endPtr - blockStream.startPtr),
                 (unsigned)dstCapacity);
 
     /* first symbols */
     FSE_initCState2(&stateMatchLength, CTable_MatchLength, mlCodeTable[nbSeq-1]);
     FSE_initCState2(&stateOffsetBits,  CTable_OffsetBits,  ofCodeTable[nbSeq-1]);
     FSE_initCState2(&stateLitLength,   CTable_LitLength,   llCodeTable[nbSeq-1]);
     BIT_addBits(&blockStream, sequences[nbSeq-1].litLength, LL_bits[llCodeTable[nbSeq-1]]);
     if (MEM_32bits()) BIT_flushBits(&blockStream);
     BIT_addBits(&blockStream, sequences[nbSeq-1].matchLength, ML_bits[mlCodeTable[nbSeq-1]]);
     if (MEM_32bits()) BIT_flushBits(&blockStream);
     if (longOffsets) {
         U32 const ofBits = ofCodeTable[nbSeq-1];
         int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN-1);
         if (extraBits) {
             BIT_addBits(&blockStream, sequences[nbSeq-1].offset, extraBits);
             BIT_flushBits(&blockStream);
         }
         BIT_addBits(&blockStream, sequences[nbSeq-1].offset >> extraBits,
                     ofBits - extraBits);
     } else {
         BIT_addBits(&blockStream, sequences[nbSeq-1].offset, ofCodeTable[nbSeq-1]);
     }
     BIT_flushBits(&blockStream);
 
     {   size_t n;
         for (n=nbSeq-2 ; n= 64-7-(LLFSELog+MLFSELog+OffFSELog)))
                 BIT_flushBits(&blockStream);                                /* (7)*/
             BIT_addBits(&blockStream, sequences[n].litLength, llBits);
             if (MEM_32bits() && ((llBits+mlBits)>24)) BIT_flushBits(&blockStream);
             BIT_addBits(&blockStream, sequences[n].matchLength, mlBits);
             if (MEM_32bits() || (ofBits+mlBits+llBits > 56)) BIT_flushBits(&blockStream);
             if (longOffsets) {
                 int const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN-1);
                 if (extraBits) {
                     BIT_addBits(&blockStream, sequences[n].offset, extraBits);
                     BIT_flushBits(&blockStream);                            /* (7)*/
                 }
                 BIT_addBits(&blockStream, sequences[n].offset >> extraBits,
                             ofBits - extraBits);                            /* 31 */
             } else {
                 BIT_addBits(&blockStream, sequences[n].offset, ofBits);     /* 31 */
             }
             BIT_flushBits(&blockStream);                                    /* (7)*/
             DEBUGLOG(7, "remaining space : %i", (int)(blockStream.endPtr - blockStream.ptr));
     }   }
 
     DEBUGLOG(6, "ZSTD_encodeSequences: flushing ML state with %u bits", stateMatchLength.stateLog);
     FSE_flushCState(&blockStream, &stateMatchLength);
     DEBUGLOG(6, "ZSTD_encodeSequences: flushing Off state with %u bits", stateOffsetBits.stateLog);
     FSE_flushCState(&blockStream, &stateOffsetBits);
     DEBUGLOG(6, "ZSTD_encodeSequences: flushing LL state with %u bits", stateLitLength.stateLog);
     FSE_flushCState(&blockStream, &stateLitLength);
 
     {   size_t const streamSize = BIT_closeCStream(&blockStream);
         RETURN_ERROR_IF(streamSize==0, dstSize_tooSmall, "not enough space");
         return streamSize;
     }
 }
 
 static size_t
 ZSTD_encodeSequences_default(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets)
 {
     return ZSTD_encodeSequences_body(dst, dstCapacity,
                                     CTable_MatchLength, mlCodeTable,
                                     CTable_OffsetBits, ofCodeTable,
                                     CTable_LitLength, llCodeTable,
                                     sequences, nbSeq, longOffsets);
 }
 
 
 #if DYNAMIC_BMI2
 
 static TARGET_ATTRIBUTE("bmi2") size_t
 ZSTD_encodeSequences_bmi2(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets)
 {
     return ZSTD_encodeSequences_body(dst, dstCapacity,
                                     CTable_MatchLength, mlCodeTable,
                                     CTable_OffsetBits, ofCodeTable,
                                     CTable_LitLength, llCodeTable,
                                     sequences, nbSeq, longOffsets);
 }
 
 #endif
 
 size_t ZSTD_encodeSequences(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets, int bmi2)
 {
     DEBUGLOG(5, "ZSTD_encodeSequences: dstCapacity = %u", (unsigned)dstCapacity);
 #if DYNAMIC_BMI2
     if (bmi2) {
         return ZSTD_encodeSequences_bmi2(dst, dstCapacity,
                                          CTable_MatchLength, mlCodeTable,
                                          CTable_OffsetBits, ofCodeTable,
                                          CTable_LitLength, llCodeTable,
                                          sequences, nbSeq, longOffsets);
     }
 #endif
     (void)bmi2;
     return ZSTD_encodeSequences_default(dst, dstCapacity,
                                         CTable_MatchLength, mlCodeTable,
                                         CTable_OffsetBits, ofCodeTable,
                                         CTable_LitLength, llCodeTable,
                                         sequences, nbSeq, longOffsets);
 }
Index: head/sys/contrib/zstd/lib/compress/zstd_compress_sequences.h
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_compress_sequences.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_compress_sequences.h	(revision 354777)
@@ -1,47 +1,47 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #ifndef ZSTD_COMPRESS_SEQUENCES_H
 #define ZSTD_COMPRESS_SEQUENCES_H
 
 #include "fse.h" /* FSE_repeat, FSE_CTable */
 #include "zstd_internal.h" /* symbolEncodingType_e, ZSTD_strategy */
 
 typedef enum {
     ZSTD_defaultDisallowed = 0,
     ZSTD_defaultAllowed = 1
 } ZSTD_defaultPolicy_e;
 
 symbolEncodingType_e
 ZSTD_selectEncodingType(
         FSE_repeat* repeatMode, unsigned const* count, unsigned const max,
         size_t const mostFrequent, size_t nbSeq, unsigned const FSELog,
         FSE_CTable const* prevCTable,
         short const* defaultNorm, U32 defaultNormLog,
         ZSTD_defaultPolicy_e const isDefaultAllowed,
         ZSTD_strategy const strategy);
 
 size_t
 ZSTD_buildCTable(void* dst, size_t dstCapacity,
                 FSE_CTable* nextCTable, U32 FSELog, symbolEncodingType_e type,
                 unsigned* count, U32 max,
                 const BYTE* codeTable, size_t nbSeq,
                 const S16* defaultNorm, U32 defaultNormLog, U32 defaultMax,
                 const FSE_CTable* prevCTable, size_t prevCTableSize,
-                void* workspace, size_t workspaceSize);
+                void* entropyWorkspace, size_t entropyWorkspaceSize);
 
 size_t ZSTD_encodeSequences(
             void* dst, size_t dstCapacity,
             FSE_CTable const* CTable_MatchLength, BYTE const* mlCodeTable,
             FSE_CTable const* CTable_OffsetBits, BYTE const* ofCodeTable,
             FSE_CTable const* CTable_LitLength, BYTE const* llCodeTable,
             seqDef const* sequences, size_t nbSeq, int longOffsets, int bmi2);
 
 #endif /* ZSTD_COMPRESS_SEQUENCES_H */
Index: head/sys/contrib/zstd/lib/compress/zstd_cwksp.h
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_cwksp.h	(nonexistent)
+++ head/sys/contrib/zstd/lib/compress/zstd_cwksp.h	(revision 354777)
@@ -0,0 +1,535 @@
+/*
+ * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
+ */
+
+#ifndef ZSTD_CWKSP_H
+#define ZSTD_CWKSP_H
+
+/*-*************************************
+*  Dependencies
+***************************************/
+#include "zstd_internal.h"
+
+#if defined (__cplusplus)
+extern "C" {
+#endif
+
+/*-*************************************
+*  Constants
+***************************************/
+
+/* define "workspace is too large" as this number of times larger than needed */
+#define ZSTD_WORKSPACETOOLARGE_FACTOR 3
+
+/* when workspace is continuously too large
+ * during at least this number of times,
+ * context's memory usage is considered wasteful,
+ * because it's sized to handle a worst case scenario which rarely happens.
+ * In which case, resize it down to free some memory */
+#define ZSTD_WORKSPACETOOLARGE_MAXDURATION 128
+
+/* Since the workspace is effectively its own little malloc implementation /
+ * arena, when we run under ASAN, we should similarly insert redzones between
+ * each internal element of the workspace, so ASAN will catch overruns that
+ * reach outside an object but that stay inside the workspace.
+ *
+ * This defines the size of that redzone.
+ */
+#ifndef ZSTD_CWKSP_ASAN_REDZONE_SIZE
+#define ZSTD_CWKSP_ASAN_REDZONE_SIZE 128
+#endif
+
+/*-*************************************
+*  Structures
+***************************************/
+typedef enum {
+    ZSTD_cwksp_alloc_objects,
+    ZSTD_cwksp_alloc_buffers,
+    ZSTD_cwksp_alloc_aligned
+} ZSTD_cwksp_alloc_phase_e;
+
+/**
+ * Zstd fits all its internal datastructures into a single continuous buffer,
+ * so that it only needs to perform a single OS allocation (or so that a buffer
+ * can be provided to it and it can perform no allocations at all). This buffer
+ * is called the workspace.
+ *
+ * Several optimizations complicate that process of allocating memory ranges
+ * from this workspace for each internal datastructure:
+ *
+ * - These different internal datastructures have different setup requirements:
+ *
+ *   - The static objects need to be cleared once and can then be trivially
+ *     reused for each compression.
+ *
+ *   - Various buffers don't need to be initialized at all--they are always
+ *     written into before they're read.
+ *
+ *   - The matchstate tables have a unique requirement that they don't need
+ *     their memory to be totally cleared, but they do need the memory to have
+ *     some bound, i.e., a guarantee that all values in the memory they've been
+ *     allocated is less than some maximum value (which is the starting value
+ *     for the indices that they will then use for compression). When this
+ *     guarantee is provided to them, they can use the memory without any setup
+ *     work. When it can't, they have to clear the area.
+ *
+ * - These buffers also have different alignment requirements.
+ *
+ * - We would like to reuse the objects in the workspace for multiple
+ *   compressions without having to perform any expensive reallocation or
+ *   reinitialization work.
+ *
+ * - We would like to be able to efficiently reuse the workspace across
+ *   multiple compressions **even when the compression parameters change** and
+ *   we need to resize some of the objects (where possible).
+ *
+ * To attempt to manage this buffer, given these constraints, the ZSTD_cwksp
+ * abstraction was created. It works as follows:
+ *
+ * Workspace Layout:
+ *
+ * [                        ... workspace ...                         ]
+ * [objects][tables ... ->] free space [<- ... aligned][<- ... buffers]
+ *
+ * The various objects that live in the workspace are divided into the
+ * following categories, and are allocated separately:
+ *
+ * - Static objects: this is optionally the enclosing ZSTD_CCtx or ZSTD_CDict,
+ *   so that literally everything fits in a single buffer. Note: if present,
+ *   this must be the first object in the workspace, since ZSTD_free{CCtx,
+ *   CDict}() rely on a pointer comparison to see whether one or two frees are
+ *   required.
+ *
+ * - Fixed size objects: these are fixed-size, fixed-count objects that are
+ *   nonetheless "dynamically" allocated in the workspace so that we can
+ *   control how they're initialized separately from the broader ZSTD_CCtx.
+ *   Examples:
+ *   - Entropy Workspace
+ *   - 2 x ZSTD_compressedBlockState_t
+ *   - CDict dictionary contents
+ *
+ * - Tables: these are any of several different datastructures (hash tables,
+ *   chain tables, binary trees) that all respect a common format: they are
+ *   uint32_t arrays, all of whose values are between 0 and (nextSrc - base).
+ *   Their sizes depend on the cparams.
+ *
+ * - Aligned: these buffers are used for various purposes that require 4 byte
+ *   alignment, but don't require any initialization before they're used.
+ *
+ * - Buffers: these buffers are used for various purposes that don't require
+ *   any alignment or initialization before they're used. This means they can
+ *   be moved around at no cost for a new compression.
+ *
+ * Allocating Memory:
+ *
+ * The various types of objects must be allocated in order, so they can be
+ * correctly packed into the workspace buffer. That order is:
+ *
+ * 1. Objects
+ * 2. Buffers
+ * 3. Aligned
+ * 4. Tables
+ *
+ * Attempts to reserve objects of different types out of order will fail.
+ */
+typedef struct {
+    void* workspace;
+    void* workspaceEnd;
+
+    void* objectEnd;
+    void* tableEnd;
+    void* tableValidEnd;
+    void* allocStart;
+
+    int allocFailed;
+    int workspaceOversizedDuration;
+    ZSTD_cwksp_alloc_phase_e phase;
+} ZSTD_cwksp;
+
+/*-*************************************
+*  Functions
+***************************************/
+
+MEM_STATIC size_t ZSTD_cwksp_available_space(ZSTD_cwksp* ws);
+
+MEM_STATIC void ZSTD_cwksp_assert_internal_consistency(ZSTD_cwksp* ws) {
+    (void)ws;
+    assert(ws->workspace <= ws->objectEnd);
+    assert(ws->objectEnd <= ws->tableEnd);
+    assert(ws->objectEnd <= ws->tableValidEnd);
+    assert(ws->tableEnd <= ws->allocStart);
+    assert(ws->tableValidEnd <= ws->allocStart);
+    assert(ws->allocStart <= ws->workspaceEnd);
+}
+
+/**
+ * Align must be a power of 2.
+ */
+MEM_STATIC size_t ZSTD_cwksp_align(size_t size, size_t const align) {
+    size_t const mask = align - 1;
+    assert((align & mask) == 0);
+    return (size + mask) & ~mask;
+}
+
+/**
+ * Use this to determine how much space in the workspace we will consume to
+ * allocate this object. (Normally it should be exactly the size of the object,
+ * but under special conditions, like ASAN, where we pad each object, it might
+ * be larger.)
+ *
+ * Since tables aren't currently redzoned, you don't need to call through this
+ * to figure out how much space you need for the matchState tables. Everything
+ * else is though.
+ */
+MEM_STATIC size_t ZSTD_cwksp_alloc_size(size_t size) {
+#if defined (ADDRESS_SANITIZER) && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE)
+    return size + 2 * ZSTD_CWKSP_ASAN_REDZONE_SIZE;
+#else
+    return size;
+#endif
+}
+
+MEM_STATIC void ZSTD_cwksp_internal_advance_phase(
+        ZSTD_cwksp* ws, ZSTD_cwksp_alloc_phase_e phase) {
+    assert(phase >= ws->phase);
+    if (phase > ws->phase) {
+        if (ws->phase < ZSTD_cwksp_alloc_buffers &&
+                phase >= ZSTD_cwksp_alloc_buffers) {
+            ws->tableValidEnd = ws->objectEnd;
+        }
+        if (ws->phase < ZSTD_cwksp_alloc_aligned &&
+                phase >= ZSTD_cwksp_alloc_aligned) {
+            /* If unaligned allocations down from a too-large top have left us
+             * unaligned, we need to realign our alloc ptr. Technically, this
+             * can consume space that is unaccounted for in the neededSpace
+             * calculation. However, I believe this can only happen when the
+             * workspace is too large, and specifically when it is too large
+             * by a larger margin than the space that will be consumed. */
+            /* TODO: cleaner, compiler warning friendly way to do this??? */
+            ws->allocStart = (BYTE*)ws->allocStart - ((size_t)ws->allocStart & (sizeof(U32)-1));
+            if (ws->allocStart < ws->tableValidEnd) {
+                ws->tableValidEnd = ws->allocStart;
+            }
+        }
+        ws->phase = phase;
+    }
+}
+
+/**
+ * Returns whether this object/buffer/etc was allocated in this workspace.
+ */
+MEM_STATIC int ZSTD_cwksp_owns_buffer(const ZSTD_cwksp* ws, const void* ptr) {
+    return (ptr != NULL) && (ws->workspace <= ptr) && (ptr <= ws->workspaceEnd);
+}
+
+/**
+ * Internal function. Do not use directly.
+ */
+MEM_STATIC void* ZSTD_cwksp_reserve_internal(
+        ZSTD_cwksp* ws, size_t bytes, ZSTD_cwksp_alloc_phase_e phase) {
+    void* alloc;
+    void* bottom = ws->tableEnd;
+    ZSTD_cwksp_internal_advance_phase(ws, phase);
+    alloc = (BYTE *)ws->allocStart - bytes;
+
+#if defined (ADDRESS_SANITIZER) && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE)
+    /* over-reserve space */
+    alloc = (BYTE *)alloc - 2 * ZSTD_CWKSP_ASAN_REDZONE_SIZE;
+#endif
+
+    DEBUGLOG(5, "cwksp: reserving %p %zd bytes, %zd bytes remaining",
+        alloc, bytes, ZSTD_cwksp_available_space(ws) - bytes);
+    ZSTD_cwksp_assert_internal_consistency(ws);
+    assert(alloc >= bottom);
+    if (alloc < bottom) {
+        DEBUGLOG(4, "cwksp: alloc failed!");
+        ws->allocFailed = 1;
+        return NULL;
+    }
+    if (alloc < ws->tableValidEnd) {
+        ws->tableValidEnd = alloc;
+    }
+    ws->allocStart = alloc;
+
+#if defined (ADDRESS_SANITIZER) && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE)
+    /* Move alloc so there's ZSTD_CWKSP_ASAN_REDZONE_SIZE unused space on
+     * either size. */
+    alloc = (BYTE *)alloc + ZSTD_CWKSP_ASAN_REDZONE_SIZE;
+    __asan_unpoison_memory_region(alloc, bytes);
+#endif
+
+    return alloc;
+}
+
+/**
+ * Reserves and returns unaligned memory.
+ */
+MEM_STATIC BYTE* ZSTD_cwksp_reserve_buffer(ZSTD_cwksp* ws, size_t bytes) {
+    return (BYTE*)ZSTD_cwksp_reserve_internal(ws, bytes, ZSTD_cwksp_alloc_buffers);
+}
+
+/**
+ * Reserves and returns memory sized on and aligned on sizeof(unsigned).
+ */
+MEM_STATIC void* ZSTD_cwksp_reserve_aligned(ZSTD_cwksp* ws, size_t bytes) {
+    assert((bytes & (sizeof(U32)-1)) == 0);
+    return ZSTD_cwksp_reserve_internal(ws, ZSTD_cwksp_align(bytes, sizeof(U32)), ZSTD_cwksp_alloc_aligned);
+}
+
+/**
+ * Aligned on sizeof(unsigned). These buffers have the special property that
+ * their values remain constrained, allowing us to re-use them without
+ * memset()-ing them.
+ */
+MEM_STATIC void* ZSTD_cwksp_reserve_table(ZSTD_cwksp* ws, size_t bytes) {
+    const ZSTD_cwksp_alloc_phase_e phase = ZSTD_cwksp_alloc_aligned;
+    void* alloc = ws->tableEnd;
+    void* end = (BYTE *)alloc + bytes;
+    void* top = ws->allocStart;
+
+    DEBUGLOG(5, "cwksp: reserving %p table %zd bytes, %zd bytes remaining",
+        alloc, bytes, ZSTD_cwksp_available_space(ws) - bytes);
+    assert((bytes & (sizeof(U32)-1)) == 0);
+    ZSTD_cwksp_internal_advance_phase(ws, phase);
+    ZSTD_cwksp_assert_internal_consistency(ws);
+    assert(end <= top);
+    if (end > top) {
+        DEBUGLOG(4, "cwksp: table alloc failed!");
+        ws->allocFailed = 1;
+        return NULL;
+    }
+    ws->tableEnd = end;
+
+#if defined (ADDRESS_SANITIZER) && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE)
+    __asan_unpoison_memory_region(alloc, bytes);
+#endif
+
+    return alloc;
+}
+
+/**
+ * Aligned on sizeof(void*).
+ */
+MEM_STATIC void* ZSTD_cwksp_reserve_object(ZSTD_cwksp* ws, size_t bytes) {
+    size_t roundedBytes = ZSTD_cwksp_align(bytes, sizeof(void*));
+    void* alloc = ws->objectEnd;
+    void* end = (BYTE*)alloc + roundedBytes;
+
+#if defined (ADDRESS_SANITIZER) && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE)
+    /* over-reserve space */
+    end = (BYTE *)end + 2 * ZSTD_CWKSP_ASAN_REDZONE_SIZE;
+#endif
+
+    DEBUGLOG(5,
+        "cwksp: reserving %p object %zd bytes (rounded to %zd), %zd bytes remaining",
+        alloc, bytes, roundedBytes, ZSTD_cwksp_available_space(ws) - roundedBytes);
+    assert(((size_t)alloc & (sizeof(void*)-1)) == 0);
+    assert((bytes & (sizeof(void*)-1)) == 0);
+    ZSTD_cwksp_assert_internal_consistency(ws);
+    /* we must be in the first phase, no advance is possible */
+    if (ws->phase != ZSTD_cwksp_alloc_objects || end > ws->workspaceEnd) {
+        DEBUGLOG(4, "cwksp: object alloc failed!");
+        ws->allocFailed = 1;
+        return NULL;
+    }
+    ws->objectEnd = end;
+    ws->tableEnd = end;
+    ws->tableValidEnd = end;
+
+#if defined (ADDRESS_SANITIZER) && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE)
+    /* Move alloc so there's ZSTD_CWKSP_ASAN_REDZONE_SIZE unused space on
+     * either size. */
+    alloc = (BYTE *)alloc + ZSTD_CWKSP_ASAN_REDZONE_SIZE;
+    __asan_unpoison_memory_region(alloc, bytes);
+#endif
+
+    return alloc;
+}
+
+MEM_STATIC void ZSTD_cwksp_mark_tables_dirty(ZSTD_cwksp* ws) {
+    DEBUGLOG(4, "cwksp: ZSTD_cwksp_mark_tables_dirty");
+
+#if defined (MEMORY_SANITIZER) && !defined (ZSTD_MSAN_DONT_POISON_WORKSPACE)
+    /* To validate that the table re-use logic is sound, and that we don't
+     * access table space that we haven't cleaned, we re-"poison" the table
+     * space every time we mark it dirty. */
+    {
+        size_t size = (BYTE*)ws->tableValidEnd - (BYTE*)ws->objectEnd;
+        assert(__msan_test_shadow(ws->objectEnd, size) == -1);
+        __msan_poison(ws->objectEnd, size);
+    }
+#endif
+
+    assert(ws->tableValidEnd >= ws->objectEnd);
+    assert(ws->tableValidEnd <= ws->allocStart);
+    ws->tableValidEnd = ws->objectEnd;
+    ZSTD_cwksp_assert_internal_consistency(ws);
+}
+
+MEM_STATIC void ZSTD_cwksp_mark_tables_clean(ZSTD_cwksp* ws) {
+    DEBUGLOG(4, "cwksp: ZSTD_cwksp_mark_tables_clean");
+    assert(ws->tableValidEnd >= ws->objectEnd);
+    assert(ws->tableValidEnd <= ws->allocStart);
+    if (ws->tableValidEnd < ws->tableEnd) {
+        ws->tableValidEnd = ws->tableEnd;
+    }
+    ZSTD_cwksp_assert_internal_consistency(ws);
+}
+
+/**
+ * Zero the part of the allocated tables not already marked clean.
+ */
+MEM_STATIC void ZSTD_cwksp_clean_tables(ZSTD_cwksp* ws) {
+    DEBUGLOG(4, "cwksp: ZSTD_cwksp_clean_tables");
+    assert(ws->tableValidEnd >= ws->objectEnd);
+    assert(ws->tableValidEnd <= ws->allocStart);
+    if (ws->tableValidEnd < ws->tableEnd) {
+        memset(ws->tableValidEnd, 0, (BYTE*)ws->tableEnd - (BYTE*)ws->tableValidEnd);
+    }
+    ZSTD_cwksp_mark_tables_clean(ws);
+}
+
+/**
+ * Invalidates table allocations.
+ * All other allocations remain valid.
+ */
+MEM_STATIC void ZSTD_cwksp_clear_tables(ZSTD_cwksp* ws) {
+    DEBUGLOG(4, "cwksp: clearing tables!");
+
+#if defined (ADDRESS_SANITIZER) && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE)
+    {
+        size_t size = (BYTE*)ws->tableValidEnd - (BYTE*)ws->objectEnd;
+        __asan_poison_memory_region(ws->objectEnd, size);
+    }
+#endif
+
+    ws->tableEnd = ws->objectEnd;
+    ZSTD_cwksp_assert_internal_consistency(ws);
+}
+
+/**
+ * Invalidates all buffer, aligned, and table allocations.
+ * Object allocations remain valid.
+ */
+MEM_STATIC void ZSTD_cwksp_clear(ZSTD_cwksp* ws) {
+    DEBUGLOG(4, "cwksp: clearing!");
+
+#if defined (MEMORY_SANITIZER) && !defined (ZSTD_MSAN_DONT_POISON_WORKSPACE)
+    /* To validate that the context re-use logic is sound, and that we don't
+     * access stuff that this compression hasn't initialized, we re-"poison"
+     * the workspace (or at least the non-static, non-table parts of it)
+     * every time we start a new compression. */
+    {
+        size_t size = (BYTE*)ws->workspaceEnd - (BYTE*)ws->tableValidEnd;
+        __msan_poison(ws->tableValidEnd, size);
+    }
+#endif
+
+#if defined (ADDRESS_SANITIZER) && !defined (ZSTD_ASAN_DONT_POISON_WORKSPACE)
+    {
+        size_t size = (BYTE*)ws->workspaceEnd - (BYTE*)ws->objectEnd;
+        __asan_poison_memory_region(ws->objectEnd, size);
+    }
+#endif
+
+    ws->tableEnd = ws->objectEnd;
+    ws->allocStart = ws->workspaceEnd;
+    ws->allocFailed = 0;
+    if (ws->phase > ZSTD_cwksp_alloc_buffers) {
+        ws->phase = ZSTD_cwksp_alloc_buffers;
+    }
+    ZSTD_cwksp_assert_internal_consistency(ws);
+}
+
+/**
+ * The provided workspace takes ownership of the buffer [start, start+size).
+ * Any existing values in the workspace are ignored (the previously managed
+ * buffer, if present, must be separately freed).
+ */
+MEM_STATIC void ZSTD_cwksp_init(ZSTD_cwksp* ws, void* start, size_t size) {
+    DEBUGLOG(4, "cwksp: init'ing workspace with %zd bytes", size);
+    assert(((size_t)start & (sizeof(void*)-1)) == 0); /* ensure correct alignment */
+    ws->workspace = start;
+    ws->workspaceEnd = (BYTE*)start + size;
+    ws->objectEnd = ws->workspace;
+    ws->tableValidEnd = ws->objectEnd;
+    ws->phase = ZSTD_cwksp_alloc_objects;
+    ZSTD_cwksp_clear(ws);
+    ws->workspaceOversizedDuration = 0;
+    ZSTD_cwksp_assert_internal_consistency(ws);
+}
+
+MEM_STATIC size_t ZSTD_cwksp_create(ZSTD_cwksp* ws, size_t size, ZSTD_customMem customMem) {
+    void* workspace = ZSTD_malloc(size, customMem);
+    DEBUGLOG(4, "cwksp: creating new workspace with %zd bytes", size);
+    RETURN_ERROR_IF(workspace == NULL, memory_allocation);
+    ZSTD_cwksp_init(ws, workspace, size);
+    return 0;
+}
+
+MEM_STATIC void ZSTD_cwksp_free(ZSTD_cwksp* ws, ZSTD_customMem customMem) {
+    void *ptr = ws->workspace;
+    DEBUGLOG(4, "cwksp: freeing workspace");
+    memset(ws, 0, sizeof(ZSTD_cwksp));
+    ZSTD_free(ptr, customMem);
+}
+
+/**
+ * Moves the management of a workspace from one cwksp to another. The src cwksp
+ * is left in an invalid state (src must be re-init()'ed before its used again).
+ */
+MEM_STATIC void ZSTD_cwksp_move(ZSTD_cwksp* dst, ZSTD_cwksp* src) {
+    *dst = *src;
+    memset(src, 0, sizeof(ZSTD_cwksp));
+}
+
+MEM_STATIC size_t ZSTD_cwksp_sizeof(const ZSTD_cwksp* ws) {
+    return (size_t)((BYTE*)ws->workspaceEnd - (BYTE*)ws->workspace);
+}
+
+MEM_STATIC int ZSTD_cwksp_reserve_failed(const ZSTD_cwksp* ws) {
+    return ws->allocFailed;
+}
+
+/*-*************************************
+*  Functions Checking Free Space
+***************************************/
+
+MEM_STATIC size_t ZSTD_cwksp_available_space(ZSTD_cwksp* ws) {
+    return (size_t)((BYTE*)ws->allocStart - (BYTE*)ws->tableEnd);
+}
+
+MEM_STATIC int ZSTD_cwksp_check_available(ZSTD_cwksp* ws, size_t additionalNeededSpace) {
+    return ZSTD_cwksp_available_space(ws) >= additionalNeededSpace;
+}
+
+MEM_STATIC int ZSTD_cwksp_check_too_large(ZSTD_cwksp* ws, size_t additionalNeededSpace) {
+    return ZSTD_cwksp_check_available(
+        ws, additionalNeededSpace * ZSTD_WORKSPACETOOLARGE_FACTOR);
+}
+
+MEM_STATIC int ZSTD_cwksp_check_wasteful(ZSTD_cwksp* ws, size_t additionalNeededSpace) {
+    return ZSTD_cwksp_check_too_large(ws, additionalNeededSpace)
+        && ws->workspaceOversizedDuration > ZSTD_WORKSPACETOOLARGE_MAXDURATION;
+}
+
+MEM_STATIC void ZSTD_cwksp_bump_oversized_duration(
+        ZSTD_cwksp* ws, size_t additionalNeededSpace) {
+    if (ZSTD_cwksp_check_too_large(ws, additionalNeededSpace)) {
+        ws->workspaceOversizedDuration++;
+    } else {
+        ws->workspaceOversizedDuration = 0;
+    }
+}
+
+#if defined (__cplusplus)
+}
+#endif
+
+#endif /* ZSTD_CWKSP_H */

Property changes on: head/sys/contrib/zstd/lib/compress/zstd_cwksp.h
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+FreeBSD=%H
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+text/plain
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Index: head/sys/contrib/zstd/lib/compress/zstd_double_fast.c
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_double_fast.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_double_fast.c	(revision 354777)
@@ -1,519 +1,518 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #include "zstd_compress_internal.h"
 #include "zstd_double_fast.h"
 
 
 void ZSTD_fillDoubleHashTable(ZSTD_matchState_t* ms,
                               void const* end, ZSTD_dictTableLoadMethod_e dtlm)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashLarge = ms->hashTable;
     U32  const hBitsL = cParams->hashLog;
     U32  const mls = cParams->minMatch;
     U32* const hashSmall = ms->chainTable;
     U32  const hBitsS = cParams->chainLog;
     const BYTE* const base = ms->window.base;
     const BYTE* ip = base + ms->nextToUpdate;
     const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
     const U32 fastHashFillStep = 3;
 
     /* Always insert every fastHashFillStep position into the hash tables.
      * Insert the other positions into the large hash table if their entry
      * is empty.
      */
     for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) {
         U32 const current = (U32)(ip - base);
         U32 i;
         for (i = 0; i < fastHashFillStep; ++i) {
             size_t const smHash = ZSTD_hashPtr(ip + i, hBitsS, mls);
             size_t const lgHash = ZSTD_hashPtr(ip + i, hBitsL, 8);
             if (i == 0)
                 hashSmall[smHash] = current + i;
             if (i == 0 || hashLarge[lgHash] == 0)
                 hashLarge[lgHash] = current + i;
             /* Only load extra positions for ZSTD_dtlm_full */
             if (dtlm == ZSTD_dtlm_fast)
                 break;
     }   }
 }
 
 
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_compressBlock_doubleFast_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize,
         U32 const mls /* template */, ZSTD_dictMode_e const dictMode)
 {
     ZSTD_compressionParameters const* cParams = &ms->cParams;
     U32* const hashLong = ms->hashTable;
     const U32 hBitsL = cParams->hashLog;
     U32* const hashSmall = ms->chainTable;
     const U32 hBitsS = cParams->chainLog;
     const BYTE* const base = ms->window.base;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
     const U32 lowestValid = ms->window.dictLimit;
     const U32 maxDistance = 1U << cParams->windowLog;
+    /* presumes that, if there is a dictionary, it must be using Attach mode */
     const U32 prefixLowestIndex = (endIndex - lowestValid > maxDistance) ? endIndex - maxDistance : lowestValid;
     const BYTE* const prefixLowest = base + prefixLowestIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - HASH_READ_SIZE;
     U32 offset_1=rep[0], offset_2=rep[1];
     U32 offsetSaved = 0;
 
     const ZSTD_matchState_t* const dms = ms->dictMatchState;
     const ZSTD_compressionParameters* const dictCParams =
                                      dictMode == ZSTD_dictMatchState ?
                                      &dms->cParams : NULL;
     const U32* const dictHashLong  = dictMode == ZSTD_dictMatchState ?
                                      dms->hashTable : NULL;
     const U32* const dictHashSmall = dictMode == ZSTD_dictMatchState ?
                                      dms->chainTable : NULL;
     const U32 dictStartIndex       = dictMode == ZSTD_dictMatchState ?
                                      dms->window.dictLimit : 0;
     const BYTE* const dictBase     = dictMode == ZSTD_dictMatchState ?
                                      dms->window.base : NULL;
     const BYTE* const dictStart    = dictMode == ZSTD_dictMatchState ?
                                      dictBase + dictStartIndex : NULL;
     const BYTE* const dictEnd      = dictMode == ZSTD_dictMatchState ?
                                      dms->window.nextSrc : NULL;
     const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
                                      prefixLowestIndex - (U32)(dictEnd - dictBase) :
                                      0;
     const U32 dictHBitsL           = dictMode == ZSTD_dictMatchState ?
                                      dictCParams->hashLog : hBitsL;
     const U32 dictHBitsS           = dictMode == ZSTD_dictMatchState ?
                                      dictCParams->chainLog : hBitsS;
     const U32 dictAndPrefixLength  = (U32)(ip - prefixLowest + dictEnd - dictStart);
 
     DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_generic");
 
     assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
 
     /* if a dictionary is attached, it must be within window range */
     if (dictMode == ZSTD_dictMatchState) {
         assert(lowestValid + maxDistance >= endIndex);
     }
 
     /* init */
     ip += (dictAndPrefixLength == 0);
     if (dictMode == ZSTD_noDict) {
         U32 const maxRep = (U32)(ip - prefixLowest);
         if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
     }
     if (dictMode == ZSTD_dictMatchState) {
         /* dictMatchState repCode checks don't currently handle repCode == 0
          * disabling. */
         assert(offset_1 <= dictAndPrefixLength);
         assert(offset_2 <= dictAndPrefixLength);
     }
 
     /* Main Search Loop */
     while (ip < ilimit) {   /* < instead of <=, because repcode check at (ip+1) */
         size_t mLength;
         U32 offset;
         size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8);
         size_t const h = ZSTD_hashPtr(ip, hBitsS, mls);
         size_t const dictHL = ZSTD_hashPtr(ip, dictHBitsL, 8);
         size_t const dictHS = ZSTD_hashPtr(ip, dictHBitsS, mls);
         U32 const current = (U32)(ip-base);
         U32 const matchIndexL = hashLong[h2];
         U32 matchIndexS = hashSmall[h];
         const BYTE* matchLong = base + matchIndexL;
         const BYTE* match = base + matchIndexS;
         const U32 repIndex = current + 1 - offset_1;
         const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
                             && repIndex < prefixLowestIndex) ?
                                dictBase + (repIndex - dictIndexDelta) :
                                base + repIndex;
         hashLong[h2] = hashSmall[h] = current;   /* update hash tables */
 
         /* check dictMatchState repcode */
         if (dictMode == ZSTD_dictMatchState
             && ((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
             && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
             const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
             mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
             ip++;
-            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, 0, mLength-MINMATCH);
+            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
             goto _match_stored;
         }
 
         /* check noDict repcode */
         if ( dictMode == ZSTD_noDict
           && ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
             mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
             ip++;
-            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, 0, mLength-MINMATCH);
+            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
             goto _match_stored;
         }
 
         if (matchIndexL > prefixLowestIndex) {
             /* check prefix long match */
             if (MEM_read64(matchLong) == MEM_read64(ip)) {
                 mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8;
                 offset = (U32)(ip-matchLong);
                 while (((ip>anchor) & (matchLong>prefixLowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
                 goto _match_found;
             }
         } else if (dictMode == ZSTD_dictMatchState) {
             /* check dictMatchState long match */
             U32 const dictMatchIndexL = dictHashLong[dictHL];
             const BYTE* dictMatchL = dictBase + dictMatchIndexL;
             assert(dictMatchL < dictEnd);
 
             if (dictMatchL > dictStart && MEM_read64(dictMatchL) == MEM_read64(ip)) {
                 mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8;
                 offset = (U32)(current - dictMatchIndexL - dictIndexDelta);
                 while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
                 goto _match_found;
         }   }
 
         if (matchIndexS > prefixLowestIndex) {
             /* check prefix short match */
             if (MEM_read32(match) == MEM_read32(ip)) {
                 goto _search_next_long;
             }
         } else if (dictMode == ZSTD_dictMatchState) {
             /* check dictMatchState short match */
             U32 const dictMatchIndexS = dictHashSmall[dictHS];
             match = dictBase + dictMatchIndexS;
             matchIndexS = dictMatchIndexS + dictIndexDelta;
 
             if (match > dictStart && MEM_read32(match) == MEM_read32(ip)) {
                 goto _search_next_long;
         }   }
 
         ip += ((ip-anchor) >> kSearchStrength) + 1;
         continue;
 
 _search_next_long:
 
         {   size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
             size_t const dictHLNext = ZSTD_hashPtr(ip+1, dictHBitsL, 8);
             U32 const matchIndexL3 = hashLong[hl3];
             const BYTE* matchL3 = base + matchIndexL3;
             hashLong[hl3] = current + 1;
 
             /* check prefix long +1 match */
             if (matchIndexL3 > prefixLowestIndex) {
                 if (MEM_read64(matchL3) == MEM_read64(ip+1)) {
                     mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8;
                     ip++;
                     offset = (U32)(ip-matchL3);
                     while (((ip>anchor) & (matchL3>prefixLowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */
                     goto _match_found;
                 }
             } else if (dictMode == ZSTD_dictMatchState) {
                 /* check dict long +1 match */
                 U32 const dictMatchIndexL3 = dictHashLong[dictHLNext];
                 const BYTE* dictMatchL3 = dictBase + dictMatchIndexL3;
                 assert(dictMatchL3 < dictEnd);
                 if (dictMatchL3 > dictStart && MEM_read64(dictMatchL3) == MEM_read64(ip+1)) {
                     mLength = ZSTD_count_2segments(ip+1+8, dictMatchL3+8, iend, dictEnd, prefixLowest) + 8;
                     ip++;
                     offset = (U32)(current + 1 - dictMatchIndexL3 - dictIndexDelta);
                     while (((ip>anchor) & (dictMatchL3>dictStart)) && (ip[-1] == dictMatchL3[-1])) { ip--; dictMatchL3--; mLength++; } /* catch up */
                     goto _match_found;
         }   }   }
 
         /* if no long +1 match, explore the short match we found */
         if (dictMode == ZSTD_dictMatchState && matchIndexS < prefixLowestIndex) {
             mLength = ZSTD_count_2segments(ip+4, match+4, iend, dictEnd, prefixLowest) + 4;
             offset = (U32)(current - matchIndexS);
             while (((ip>anchor) & (match>dictStart)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
         } else {
             mLength = ZSTD_count(ip+4, match+4, iend) + 4;
             offset = (U32)(ip - match);
             while (((ip>anchor) & (match>prefixLowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
         }
 
         /* fall-through */
 
 _match_found:
         offset_2 = offset_1;
         offset_1 = offset;
 
-        ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+        ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
 
 _match_stored:
         /* match found */
         ip += mLength;
         anchor = ip;
 
         if (ip <= ilimit) {
             /* Complementary insertion */
             /* done after iLimit test, as candidates could be > iend-8 */
             {   U32 const indexToInsert = current+2;
                 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
                 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
                 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
                 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
             }
 
             /* check immediate repcode */
             if (dictMode == ZSTD_dictMatchState) {
                 while (ip <= ilimit) {
                     U32 const current2 = (U32)(ip-base);
                     U32 const repIndex2 = current2 - offset_2;
                     const BYTE* repMatch2 = dictMode == ZSTD_dictMatchState
                         && repIndex2 < prefixLowestIndex ?
                             dictBase - dictIndexDelta + repIndex2 :
                             base + repIndex2;
                     if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
                        && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
                         const BYTE* const repEnd2 = repIndex2 < prefixLowestIndex ? dictEnd : iend;
                         size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixLowest) + 4;
                         U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
-                        ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
+                        ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, repLength2-MINMATCH);
                         hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
                         hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
                         ip += repLength2;
                         anchor = ip;
                         continue;
                     }
                     break;
             }   }
 
             if (dictMode == ZSTD_noDict) {
                 while ( (ip <= ilimit)
                      && ( (offset_2>0)
                         & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
                     /* store sequence */
                     size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
                     U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff;  /* swap offset_2 <=> offset_1 */
                     hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base);
                     hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base);
-                    ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH);
+                    ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, rLength-MINMATCH);
                     ip += rLength;
                     anchor = ip;
                     continue;   /* faster when present ... (?) */
         }   }   }
     }   /* while (ip < ilimit) */
 
     /* save reps for next block */
     rep[0] = offset_1 ? offset_1 : offsetSaved;
     rep[1] = offset_2 ? offset_2 : offsetSaved;
 
     /* Return the last literals size */
     return (size_t)(iend - anchor);
 }
 
 
 size_t ZSTD_compressBlock_doubleFast(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
     const U32 mls = ms->cParams.minMatch;
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_noDict);
     case 5 :
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_noDict);
     case 6 :
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_noDict);
     case 7 :
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_noDict);
     }
 }
 
 
 size_t ZSTD_compressBlock_doubleFast_dictMatchState(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
     const U32 mls = ms->cParams.minMatch;
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_dictMatchState);
     case 5 :
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_dictMatchState);
     case 6 :
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_dictMatchState);
     case 7 :
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_dictMatchState);
     }
 }
 
 
 static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize,
         U32 const mls /* template */)
 {
     ZSTD_compressionParameters const* cParams = &ms->cParams;
     U32* const hashLong = ms->hashTable;
     U32  const hBitsL = cParams->hashLog;
     U32* const hashSmall = ms->chainTable;
     U32  const hBitsS = cParams->chainLog;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
     const BYTE* const base = ms->window.base;
     const U32   endIndex = (U32)((size_t)(istart - base) + srcSize);
-    const U32   maxDistance = 1U << cParams->windowLog;
-    const U32   lowestValid = ms->window.lowLimit;
-    const U32   lowLimit = (endIndex - lowestValid > maxDistance) ? endIndex - maxDistance : lowestValid;
+    const U32   lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog);
     const U32   dictStartIndex = lowLimit;
     const U32   dictLimit = ms->window.dictLimit;
     const U32   prefixStartIndex = (dictLimit > lowLimit) ? dictLimit : lowLimit;
     const BYTE* const prefixStart = base + prefixStartIndex;
     const BYTE* const dictBase = ms->window.dictBase;
     const BYTE* const dictStart = dictBase + dictStartIndex;
     const BYTE* const dictEnd = dictBase + prefixStartIndex;
     U32 offset_1=rep[0], offset_2=rep[1];
 
     DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_extDict_generic (srcSize=%zu)", srcSize);
 
     /* if extDict is invalidated due to maxDistance, switch to "regular" variant */
     if (prefixStartIndex == dictStartIndex)
         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, mls, ZSTD_noDict);
 
     /* Search Loop */
     while (ip < ilimit) {  /* < instead of <=, because (ip+1) */
         const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
         const U32 matchIndex = hashSmall[hSmall];
         const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
         const BYTE* match = matchBase + matchIndex;
 
         const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8);
         const U32 matchLongIndex = hashLong[hLong];
         const BYTE* const matchLongBase = matchLongIndex < prefixStartIndex ? dictBase : base;
         const BYTE* matchLong = matchLongBase + matchLongIndex;
 
         const U32 current = (U32)(ip-base);
         const U32 repIndex = current + 1 - offset_1;   /* offset_1 expected <= current +1 */
         const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
         const BYTE* const repMatch = repBase + repIndex;
         size_t mLength;
         hashSmall[hSmall] = hashLong[hLong] = current;   /* update hash table */
 
         if ((((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex doesn't overlap dict + prefix */
             & (repIndex > dictStartIndex))
           && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
             const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
             mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
             ip++;
-            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, 0, mLength-MINMATCH);
+            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
         } else {
             if ((matchLongIndex > dictStartIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
                 const BYTE* const matchEnd = matchLongIndex < prefixStartIndex ? dictEnd : iend;
                 const BYTE* const lowMatchPtr = matchLongIndex < prefixStartIndex ? dictStart : prefixStart;
                 U32 offset;
                 mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, prefixStart) + 8;
                 offset = current - matchLongIndex;
                 while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; }   /* catch up */
                 offset_2 = offset_1;
                 offset_1 = offset;
-                ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+                ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
 
             } else if ((matchIndex > dictStartIndex) && (MEM_read32(match) == MEM_read32(ip))) {
                 size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
                 U32 const matchIndex3 = hashLong[h3];
                 const BYTE* const match3Base = matchIndex3 < prefixStartIndex ? dictBase : base;
                 const BYTE* match3 = match3Base + matchIndex3;
                 U32 offset;
                 hashLong[h3] = current + 1;
                 if ( (matchIndex3 > dictStartIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
                     const BYTE* const matchEnd = matchIndex3 < prefixStartIndex ? dictEnd : iend;
                     const BYTE* const lowMatchPtr = matchIndex3 < prefixStartIndex ? dictStart : prefixStart;
                     mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, prefixStart) + 8;
                     ip++;
                     offset = current+1 - matchIndex3;
                     while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
                 } else {
                     const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
                     const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
                     mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
                     offset = current - matchIndex;
                     while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; }   /* catch up */
                 }
                 offset_2 = offset_1;
                 offset_1 = offset;
-                ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+                ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
 
             } else {
                 ip += ((ip-anchor) >> kSearchStrength) + 1;
                 continue;
         }   }
 
         /* move to next sequence start */
         ip += mLength;
         anchor = ip;
 
         if (ip <= ilimit) {
             /* Complementary insertion */
             /* done after iLimit test, as candidates could be > iend-8 */
             {   U32 const indexToInsert = current+2;
                 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
                 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
                 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
                 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
             }
 
             /* check immediate repcode */
             while (ip <= ilimit) {
                 U32 const current2 = (U32)(ip-base);
                 U32 const repIndex2 = current2 - offset_2;
                 const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
                 if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3)   /* intentional overflow : ensure repIndex2 doesn't overlap dict + prefix */
                     & (repIndex2 > dictStartIndex))
                   && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
                     const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
                     size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
                     U32 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
-                    ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
+                    ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, repLength2-MINMATCH);
                     hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
                     hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
                     ip += repLength2;
                     anchor = ip;
                     continue;
                 }
                 break;
     }   }   }
 
     /* save reps for next block */
     rep[0] = offset_1;
     rep[1] = offset_2;
 
     /* Return the last literals size */
     return (size_t)(iend - anchor);
 }
 
 
 size_t ZSTD_compressBlock_doubleFast_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
     U32 const mls = ms->cParams.minMatch;
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
         return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 4);
     case 5 :
         return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 5);
     case 6 :
         return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 6);
     case 7 :
         return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 7);
     }
 }
Index: head/sys/contrib/zstd/lib/compress/zstd_fast.c
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_fast.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_fast.c	(revision 354777)
@@ -1,491 +1,484 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
-#include "zstd_compress_internal.h"
+#include "zstd_compress_internal.h"  /* ZSTD_hashPtr, ZSTD_count, ZSTD_storeSeq */
 #include "zstd_fast.h"
 
 
 void ZSTD_fillHashTable(ZSTD_matchState_t* ms,
                         const void* const end,
                         ZSTD_dictTableLoadMethod_e dtlm)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashTable = ms->hashTable;
     U32  const hBits = cParams->hashLog;
     U32  const mls = cParams->minMatch;
     const BYTE* const base = ms->window.base;
     const BYTE* ip = base + ms->nextToUpdate;
     const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
     const U32 fastHashFillStep = 3;
 
     /* Always insert every fastHashFillStep position into the hash table.
      * Insert the other positions if their hash entry is empty.
      */
     for ( ; ip + fastHashFillStep < iend + 2; ip += fastHashFillStep) {
         U32 const current = (U32)(ip - base);
         size_t const hash0 = ZSTD_hashPtr(ip, hBits, mls);
         hashTable[hash0] = current;
         if (dtlm == ZSTD_dtlm_fast) continue;
         /* Only load extra positions for ZSTD_dtlm_full */
         {   U32 p;
             for (p = 1; p < fastHashFillStep; ++p) {
                 size_t const hash = ZSTD_hashPtr(ip + p, hBits, mls);
                 if (hashTable[hash] == 0) {  /* not yet filled */
                     hashTable[hash] = current + p;
     }   }   }   }
 }
 
 
-FORCE_INLINE_TEMPLATE
-size_t ZSTD_compressBlock_fast_generic(
+FORCE_INLINE_TEMPLATE size_t
+ZSTD_compressBlock_fast_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize,
         U32 const mls)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashTable = ms->hashTable;
     U32 const hlog = cParams->hashLog;
     /* support stepSize of 0 */
     size_t const stepSize = cParams->targetLength + !(cParams->targetLength) + 1;
     const BYTE* const base = ms->window.base;
     const BYTE* const istart = (const BYTE*)src;
     /* We check ip0 (ip + 0) and ip1 (ip + 1) each loop */
     const BYTE* ip0 = istart;
     const BYTE* ip1;
     const BYTE* anchor = istart;
     const U32   endIndex = (U32)((size_t)(istart - base) + srcSize);
     const U32   maxDistance = 1U << cParams->windowLog;
     const U32   validStartIndex = ms->window.dictLimit;
     const U32   prefixStartIndex = (endIndex - validStartIndex > maxDistance) ? endIndex - maxDistance : validStartIndex;
     const BYTE* const prefixStart = base + prefixStartIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - HASH_READ_SIZE;
     U32 offset_1=rep[0], offset_2=rep[1];
     U32 offsetSaved = 0;
 
     /* init */
+    DEBUGLOG(5, "ZSTD_compressBlock_fast_generic");
     ip0 += (ip0 == prefixStart);
     ip1 = ip0 + 1;
-    {
-        U32 const maxRep = (U32)(ip0 - prefixStart);
+    {   U32 const maxRep = (U32)(ip0 - prefixStart);
         if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
     }
 
     /* Main Search Loop */
     while (ip1 < ilimit) {   /* < instead of <=, because check at ip0+2 */
         size_t mLength;
         BYTE const* ip2 = ip0 + 2;
         size_t const h0 = ZSTD_hashPtr(ip0, hlog, mls);
         U32 const val0 = MEM_read32(ip0);
         size_t const h1 = ZSTD_hashPtr(ip1, hlog, mls);
         U32 const val1 = MEM_read32(ip1);
         U32 const current0 = (U32)(ip0-base);
         U32 const current1 = (U32)(ip1-base);
         U32 const matchIndex0 = hashTable[h0];
         U32 const matchIndex1 = hashTable[h1];
         BYTE const* repMatch = ip2-offset_1;
         const BYTE* match0 = base + matchIndex0;
         const BYTE* match1 = base + matchIndex1;
         U32 offcode;
         hashTable[h0] = current0;   /* update hash table */
         hashTable[h1] = current1;   /* update hash table */
 
         assert(ip0 + 1 == ip1);
 
         if ((offset_1 > 0) & (MEM_read32(repMatch) == MEM_read32(ip2))) {
             mLength = ip2[-1] == repMatch[-1] ? 1 : 0;
             ip0 = ip2 - mLength;
             match0 = repMatch - mLength;
             offcode = 0;
             goto _match;
         }
         if ((matchIndex0 > prefixStartIndex) && MEM_read32(match0) == val0) {
             /* found a regular match */
             goto _offset;
         }
         if ((matchIndex1 > prefixStartIndex) && MEM_read32(match1) == val1) {
             /* found a regular match after one literal */
             ip0 = ip1;
             match0 = match1;
             goto _offset;
         }
-        {
-            size_t const step = ((ip0-anchor) >> (kSearchStrength - 1)) + stepSize;
+        {   size_t const step = ((size_t)(ip0-anchor) >> (kSearchStrength - 1)) + stepSize;
             assert(step >= 2);
             ip0 += step;
             ip1 += step;
             continue;
         }
 _offset: /* Requires: ip0, match0 */
         /* Compute the offset code */
         offset_2 = offset_1;
         offset_1 = (U32)(ip0-match0);
         offcode = offset_1 + ZSTD_REP_MOVE;
         mLength = 0;
         /* Count the backwards match length */
         while (((ip0>anchor) & (match0>prefixStart))
              && (ip0[-1] == match0[-1])) { ip0--; match0--; mLength++; } /* catch up */
 
 _match: /* Requires: ip0, match0, offcode */
         /* Count the forward length */
         mLength += ZSTD_count(ip0+mLength+4, match0+mLength+4, iend) + 4;
-        ZSTD_storeSeq(seqStore, ip0-anchor, anchor, offcode, mLength-MINMATCH);
+        ZSTD_storeSeq(seqStore, (size_t)(ip0-anchor), anchor, iend, offcode, mLength-MINMATCH);
         /* match found */
         ip0 += mLength;
         anchor = ip0;
         ip1 = ip0 + 1;
 
         if (ip0 <= ilimit) {
             /* Fill Table */
             assert(base+current0+2 > istart);  /* check base overflow */
             hashTable[ZSTD_hashPtr(base+current0+2, hlog, mls)] = current0+2;  /* here because current+2 could be > iend-8 */
             hashTable[ZSTD_hashPtr(ip0-2, hlog, mls)] = (U32)(ip0-2-base);
 
-            while ( (ip0 <= ilimit)
-                 && ( (offset_2>0)
-                    & (MEM_read32(ip0) == MEM_read32(ip0 - offset_2)) )) {
+            while ( ((ip0 <= ilimit) & (offset_2>0))  /* offset_2==0 means offset_2 is invalidated */
+                 && (MEM_read32(ip0) == MEM_read32(ip0 - offset_2)) ) {
                 /* store sequence */
                 size_t const rLength = ZSTD_count(ip0+4, ip0+4-offset_2, iend) + 4;
-                U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff;  /* swap offset_2 <=> offset_1 */
+                { U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; } /* swap offset_2 <=> offset_1 */
                 hashTable[ZSTD_hashPtr(ip0, hlog, mls)] = (U32)(ip0-base);
                 ip0 += rLength;
                 ip1 = ip0 + 1;
-                ZSTD_storeSeq(seqStore, 0, anchor, 0, rLength-MINMATCH);
+                ZSTD_storeSeq(seqStore, 0 /*litLen*/, anchor, iend, 0 /*offCode*/, rLength-MINMATCH);
                 anchor = ip0;
                 continue;   /* faster when present (confirmed on gcc-8) ... (?) */
             }
         }
     }
 
     /* save reps for next block */
     rep[0] = offset_1 ? offset_1 : offsetSaved;
     rep[1] = offset_2 ? offset_2 : offsetSaved;
 
     /* Return the last literals size */
     return (size_t)(iend - anchor);
 }
 
 
 size_t ZSTD_compressBlock_fast(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    ZSTD_compressionParameters const* cParams = &ms->cParams;
-    U32 const mls = cParams->minMatch;
+    U32 const mls = ms->cParams.minMatch;
     assert(ms->dictMatchState == NULL);
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
         return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 4);
     case 5 :
         return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 5);
     case 6 :
         return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 6);
     case 7 :
         return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, 7);
     }
 }
 
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_compressBlock_fast_dictMatchState_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize, U32 const mls)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashTable = ms->hashTable;
     U32 const hlog = cParams->hashLog;
     /* support stepSize of 0 */
     U32 const stepSize = cParams->targetLength + !(cParams->targetLength);
     const BYTE* const base = ms->window.base;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const U32   prefixStartIndex = ms->window.dictLimit;
     const BYTE* const prefixStart = base + prefixStartIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - HASH_READ_SIZE;
     U32 offset_1=rep[0], offset_2=rep[1];
     U32 offsetSaved = 0;
 
     const ZSTD_matchState_t* const dms = ms->dictMatchState;
     const ZSTD_compressionParameters* const dictCParams = &dms->cParams ;
     const U32* const dictHashTable = dms->hashTable;
     const U32 dictStartIndex       = dms->window.dictLimit;
     const BYTE* const dictBase     = dms->window.base;
     const BYTE* const dictStart    = dictBase + dictStartIndex;
     const BYTE* const dictEnd      = dms->window.nextSrc;
     const U32 dictIndexDelta       = prefixStartIndex - (U32)(dictEnd - dictBase);
     const U32 dictAndPrefixLength  = (U32)(ip - prefixStart + dictEnd - dictStart);
     const U32 dictHLog             = dictCParams->hashLog;
 
     /* if a dictionary is still attached, it necessarily means that
      * it is within window size. So we just check it. */
     const U32 maxDistance = 1U << cParams->windowLog;
     const U32 endIndex = (U32)((size_t)(ip - base) + srcSize);
     assert(endIndex - prefixStartIndex <= maxDistance);
     (void)maxDistance; (void)endIndex;   /* these variables are not used when assert() is disabled */
 
     /* ensure there will be no no underflow
      * when translating a dict index into a local index */
     assert(prefixStartIndex >= (U32)(dictEnd - dictBase));
 
     /* init */
+    DEBUGLOG(5, "ZSTD_compressBlock_fast_dictMatchState_generic");
     ip += (dictAndPrefixLength == 0);
     /* dictMatchState repCode checks don't currently handle repCode == 0
      * disabling. */
     assert(offset_1 <= dictAndPrefixLength);
     assert(offset_2 <= dictAndPrefixLength);
 
     /* Main Search Loop */
     while (ip < ilimit) {   /* < instead of <=, because repcode check at (ip+1) */
         size_t mLength;
         size_t const h = ZSTD_hashPtr(ip, hlog, mls);
         U32 const current = (U32)(ip-base);
         U32 const matchIndex = hashTable[h];
         const BYTE* match = base + matchIndex;
         const U32 repIndex = current + 1 - offset_1;
         const BYTE* repMatch = (repIndex < prefixStartIndex) ?
                                dictBase + (repIndex - dictIndexDelta) :
                                base + repIndex;
         hashTable[h] = current;   /* update hash table */
 
         if ( ((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex isn't overlapping dict + prefix */
           && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
             const BYTE* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
             mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
             ip++;
-            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, 0, mLength-MINMATCH);
+            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
         } else if ( (matchIndex <= prefixStartIndex) ) {
             size_t const dictHash = ZSTD_hashPtr(ip, dictHLog, mls);
             U32 const dictMatchIndex = dictHashTable[dictHash];
             const BYTE* dictMatch = dictBase + dictMatchIndex;
             if (dictMatchIndex <= dictStartIndex ||
                 MEM_read32(dictMatch) != MEM_read32(ip)) {
                 assert(stepSize >= 1);
                 ip += ((ip-anchor) >> kSearchStrength) + stepSize;
                 continue;
             } else {
                 /* found a dict match */
                 U32 const offset = (U32)(current-dictMatchIndex-dictIndexDelta);
                 mLength = ZSTD_count_2segments(ip+4, dictMatch+4, iend, dictEnd, prefixStart) + 4;
                 while (((ip>anchor) & (dictMatch>dictStart))
                      && (ip[-1] == dictMatch[-1])) {
                     ip--; dictMatch--; mLength++;
                 } /* catch up */
                 offset_2 = offset_1;
                 offset_1 = offset;
-                ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+                ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
             }
         } else if (MEM_read32(match) != MEM_read32(ip)) {
             /* it's not a match, and we're not going to check the dictionary */
             assert(stepSize >= 1);
             ip += ((ip-anchor) >> kSearchStrength) + stepSize;
             continue;
         } else {
             /* found a regular match */
             U32 const offset = (U32)(ip-match);
             mLength = ZSTD_count(ip+4, match+4, iend) + 4;
             while (((ip>anchor) & (match>prefixStart))
                  && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
             offset_2 = offset_1;
             offset_1 = offset;
-            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
         }
 
         /* match found */
         ip += mLength;
         anchor = ip;
 
         if (ip <= ilimit) {
             /* Fill Table */
             assert(base+current+2 > istart);  /* check base overflow */
             hashTable[ZSTD_hashPtr(base+current+2, hlog, mls)] = current+2;  /* here because current+2 could be > iend-8 */
             hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base);
 
             /* check immediate repcode */
             while (ip <= ilimit) {
                 U32 const current2 = (U32)(ip-base);
                 U32 const repIndex2 = current2 - offset_2;
                 const BYTE* repMatch2 = repIndex2 < prefixStartIndex ?
                         dictBase - dictIndexDelta + repIndex2 :
                         base + repIndex2;
                 if ( ((U32)((prefixStartIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
                    && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
                     const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
                     size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
                     U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
-                    ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
+                    ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, repLength2-MINMATCH);
                     hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2;
                     ip += repLength2;
                     anchor = ip;
                     continue;
                 }
                 break;
             }
         }
     }
 
     /* save reps for next block */
     rep[0] = offset_1 ? offset_1 : offsetSaved;
     rep[1] = offset_2 ? offset_2 : offsetSaved;
 
     /* Return the last literals size */
     return (size_t)(iend - anchor);
 }
 
 size_t ZSTD_compressBlock_fast_dictMatchState(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    ZSTD_compressionParameters const* cParams = &ms->cParams;
-    U32 const mls = cParams->minMatch;
+    U32 const mls = ms->cParams.minMatch;
     assert(ms->dictMatchState != NULL);
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
         return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 4);
     case 5 :
         return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 5);
     case 6 :
         return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 6);
     case 7 :
         return ZSTD_compressBlock_fast_dictMatchState_generic(ms, seqStore, rep, src, srcSize, 7);
     }
 }
 
 
 static size_t ZSTD_compressBlock_fast_extDict_generic(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize, U32 const mls)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashTable = ms->hashTable;
     U32 const hlog = cParams->hashLog;
     /* support stepSize of 0 */
     U32 const stepSize = cParams->targetLength + !(cParams->targetLength);
     const BYTE* const base = ms->window.base;
     const BYTE* const dictBase = ms->window.dictBase;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const U32   endIndex = (U32)((size_t)(istart - base) + srcSize);
-    const U32   maxDistance = 1U << cParams->windowLog;
-    const U32   validLow = ms->window.lowLimit;
-    const U32   lowLimit = (endIndex - validLow > maxDistance) ? endIndex - maxDistance : validLow;
+    const U32   lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog);
     const U32   dictStartIndex = lowLimit;
     const BYTE* const dictStart = dictBase + dictStartIndex;
     const U32   dictLimit = ms->window.dictLimit;
     const U32   prefixStartIndex = dictLimit < lowLimit ? lowLimit : dictLimit;
     const BYTE* const prefixStart = base + prefixStartIndex;
     const BYTE* const dictEnd = dictBase + prefixStartIndex;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
     U32 offset_1=rep[0], offset_2=rep[1];
 
+    DEBUGLOG(5, "ZSTD_compressBlock_fast_extDict_generic");
+
     /* switch to "regular" variant if extDict is invalidated due to maxDistance */
     if (prefixStartIndex == dictStartIndex)
         return ZSTD_compressBlock_fast_generic(ms, seqStore, rep, src, srcSize, mls);
 
     /* Search Loop */
     while (ip < ilimit) {  /* < instead of <=, because (ip+1) */
         const size_t h = ZSTD_hashPtr(ip, hlog, mls);
         const U32    matchIndex = hashTable[h];
         const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
         const BYTE*  match = matchBase + matchIndex;
         const U32    current = (U32)(ip-base);
         const U32    repIndex = current + 1 - offset_1;
         const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
         const BYTE* const repMatch = repBase + repIndex;
-        size_t mLength;
         hashTable[h] = current;   /* update hash table */
         assert(offset_1 <= current +1);   /* check repIndex */
 
         if ( (((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > dictStartIndex))
            && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
-            const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
-            mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
+            const BYTE* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
+            size_t const rLength = ZSTD_count_2segments(ip+1 +4, repMatch +4, iend, repMatchEnd, prefixStart) + 4;
             ip++;
-            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, 0, mLength-MINMATCH);
+            ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, rLength-MINMATCH);
+            ip += rLength;
+            anchor = ip;
         } else {
             if ( (matchIndex < dictStartIndex) ||
                  (MEM_read32(match) != MEM_read32(ip)) ) {
                 assert(stepSize >= 1);
                 ip += ((ip-anchor) >> kSearchStrength) + stepSize;
                 continue;
             }
-            {   const BYTE* matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
-                const BYTE* lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
-                U32 offset;
-                mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
+            {   const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
+                const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
+                U32 const offset = current - matchIndex;
+                size_t mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
                 while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; }   /* catch up */
-                offset = current - matchIndex;
-                offset_2 = offset_1;
-                offset_1 = offset;
-                ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+                offset_2 = offset_1; offset_1 = offset;  /* update offset history */
+                ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
+                ip += mLength;
+                anchor = ip;
         }   }
 
-        /* found a match : store it */
-        ip += mLength;
-        anchor = ip;
-
         if (ip <= ilimit) {
             /* Fill Table */
             hashTable[ZSTD_hashPtr(base+current+2, hlog, mls)] = current+2;
             hashTable[ZSTD_hashPtr(ip-2, hlog, mls)] = (U32)(ip-2-base);
             /* check immediate repcode */
             while (ip <= ilimit) {
                 U32 const current2 = (U32)(ip-base);
                 U32 const repIndex2 = current2 - offset_2;
-                const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
+                const BYTE* const repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
                 if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) & (repIndex2 > dictStartIndex))  /* intentional overflow */
                    && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
                     const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
                     size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
-                    U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
-                    ZSTD_storeSeq(seqStore, 0, anchor, 0, repLength2-MINMATCH);
+                    { U32 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; }  /* swap offset_2 <=> offset_1 */
+                    ZSTD_storeSeq(seqStore, 0 /*litlen*/, anchor, iend, 0 /*offcode*/, repLength2-MINMATCH);
                     hashTable[ZSTD_hashPtr(ip, hlog, mls)] = current2;
                     ip += repLength2;
                     anchor = ip;
                     continue;
                 }
                 break;
     }   }   }
 
     /* save reps for next block */
     rep[0] = offset_1;
     rep[1] = offset_2;
 
     /* Return the last literals size */
     return (size_t)(iend - anchor);
 }
 
 
 size_t ZSTD_compressBlock_fast_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    ZSTD_compressionParameters const* cParams = &ms->cParams;
-    U32 const mls = cParams->minMatch;
+    U32 const mls = ms->cParams.minMatch;
     switch(mls)
     {
     default: /* includes case 3 */
     case 4 :
         return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 4);
     case 5 :
         return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 5);
     case 6 :
         return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 6);
     case 7 :
         return ZSTD_compressBlock_fast_extDict_generic(ms, seqStore, rep, src, srcSize, 7);
     }
 }
Index: head/sys/contrib/zstd/lib/compress/zstd_lazy.c
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_lazy.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_lazy.c	(revision 354777)
@@ -1,1111 +1,1115 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #include "zstd_compress_internal.h"
 #include "zstd_lazy.h"
 
 
 /*-*************************************
 *  Binary Tree search
 ***************************************/
 
 static void
 ZSTD_updateDUBT(ZSTD_matchState_t* ms,
                 const BYTE* ip, const BYTE* iend,
                 U32 mls)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const hashTable = ms->hashTable;
     U32  const hashLog = cParams->hashLog;
 
     U32* const bt = ms->chainTable;
     U32  const btLog  = cParams->chainLog - 1;
     U32  const btMask = (1 << btLog) - 1;
 
     const BYTE* const base = ms->window.base;
     U32 const target = (U32)(ip - base);
     U32 idx = ms->nextToUpdate;
 
     if (idx != target)
         DEBUGLOG(7, "ZSTD_updateDUBT, from %u to %u (dictLimit:%u)",
                     idx, target, ms->window.dictLimit);
     assert(ip + 8 <= iend);   /* condition for ZSTD_hashPtr */
     (void)iend;
 
     assert(idx >= ms->window.dictLimit);   /* condition for valid base+idx */
     for ( ; idx < target ; idx++) {
         size_t const h  = ZSTD_hashPtr(base + idx, hashLog, mls);   /* assumption : ip + 8 <= iend */
         U32    const matchIndex = hashTable[h];
 
         U32*   const nextCandidatePtr = bt + 2*(idx&btMask);
         U32*   const sortMarkPtr  = nextCandidatePtr + 1;
 
         DEBUGLOG(8, "ZSTD_updateDUBT: insert %u", idx);
         hashTable[h] = idx;   /* Update Hash Table */
         *nextCandidatePtr = matchIndex;   /* update BT like a chain */
         *sortMarkPtr = ZSTD_DUBT_UNSORTED_MARK;
     }
     ms->nextToUpdate = target;
 }
 
 
 /** ZSTD_insertDUBT1() :
  *  sort one already inserted but unsorted position
  *  assumption : current >= btlow == (current - btmask)
  *  doesn't fail */
 static void
 ZSTD_insertDUBT1(ZSTD_matchState_t* ms,
                  U32 current, const BYTE* inputEnd,
                  U32 nbCompares, U32 btLow,
                  const ZSTD_dictMode_e dictMode)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const bt = ms->chainTable;
     U32  const btLog  = cParams->chainLog - 1;
     U32  const btMask = (1 << btLog) - 1;
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const base = ms->window.base;
     const BYTE* const dictBase = ms->window.dictBase;
     const U32 dictLimit = ms->window.dictLimit;
     const BYTE* const ip = (current>=dictLimit) ? base + current : dictBase + current;
     const BYTE* const iend = (current>=dictLimit) ? inputEnd : dictBase + dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* match;
     U32* smallerPtr = bt + 2*(current&btMask);
     U32* largerPtr  = smallerPtr + 1;
     U32 matchIndex = *smallerPtr;   /* this candidate is unsorted : next sorted candidate is reached through *smallerPtr, while *largerPtr contains previous unsorted candidate (which is already saved and can be overwritten) */
     U32 dummy32;   /* to be nullified at the end */
     U32 const windowValid = ms->window.lowLimit;
     U32 const maxDistance = 1U << cParams->windowLog;
     U32 const windowLow = (current - windowValid > maxDistance) ? current - maxDistance : windowValid;
 
 
     DEBUGLOG(8, "ZSTD_insertDUBT1(%u) (dictLimit=%u, lowLimit=%u)",
                 current, dictLimit, windowLow);
     assert(current >= btLow);
     assert(ip < iend);   /* condition for ZSTD_count */
 
     while (nbCompares-- && (matchIndex > windowLow)) {
         U32* const nextPtr = bt + 2*(matchIndex & btMask);
         size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
         assert(matchIndex < current);
         /* note : all candidates are now supposed sorted,
          * but it's still possible to have nextPtr[1] == ZSTD_DUBT_UNSORTED_MARK
          * when a real index has the same value as ZSTD_DUBT_UNSORTED_MARK */
 
         if ( (dictMode != ZSTD_extDict)
           || (matchIndex+matchLength >= dictLimit)  /* both in current segment*/
           || (current < dictLimit) /* both in extDict */) {
             const BYTE* const mBase = ( (dictMode != ZSTD_extDict)
                                      || (matchIndex+matchLength >= dictLimit)) ?
                                         base : dictBase;
             assert( (matchIndex+matchLength >= dictLimit)   /* might be wrong if extDict is incorrectly set to 0 */
                  || (current < dictLimit) );
             match = mBase + matchIndex;
             matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
         } else {
             match = dictBase + matchIndex;
             matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
             if (matchIndex+matchLength >= dictLimit)
                 match = base + matchIndex;   /* preparation for next read of match[matchLength] */
         }
 
         DEBUGLOG(8, "ZSTD_insertDUBT1: comparing %u with %u : found %u common bytes ",
                     current, matchIndex, (U32)matchLength);
 
         if (ip+matchLength == iend) {   /* equal : no way to know if inf or sup */
             break;   /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */
         }
 
         if (match[matchLength] < ip[matchLength]) {  /* necessarily within buffer */
             /* match is smaller than current */
             *smallerPtr = matchIndex;             /* update smaller idx */
             commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
             if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop searching */
             DEBUGLOG(8, "ZSTD_insertDUBT1: %u (>btLow=%u) is smaller : next => %u",
                         matchIndex, btLow, nextPtr[1]);
             smallerPtr = nextPtr+1;               /* new "candidate" => larger than match, which was smaller than target */
             matchIndex = nextPtr[1];              /* new matchIndex, larger than previous and closer to current */
         } else {
             /* match is larger than current */
             *largerPtr = matchIndex;
             commonLengthLarger = matchLength;
             if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop searching */
             DEBUGLOG(8, "ZSTD_insertDUBT1: %u (>btLow=%u) is larger => %u",
                         matchIndex, btLow, nextPtr[0]);
             largerPtr = nextPtr;
             matchIndex = nextPtr[0];
     }   }
 
     *smallerPtr = *largerPtr = 0;
 }
 
 
 static size_t
 ZSTD_DUBT_findBetterDictMatch (
         ZSTD_matchState_t* ms,
         const BYTE* const ip, const BYTE* const iend,
         size_t* offsetPtr,
         size_t bestLength,
         U32 nbCompares,
         U32 const mls,
         const ZSTD_dictMode_e dictMode)
 {
     const ZSTD_matchState_t * const dms = ms->dictMatchState;
     const ZSTD_compressionParameters* const dmsCParams = &dms->cParams;
     const U32 * const dictHashTable = dms->hashTable;
     U32         const hashLog = dmsCParams->hashLog;
     size_t      const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32               dictMatchIndex = dictHashTable[h];
 
     const BYTE* const base = ms->window.base;
     const BYTE* const prefixStart = base + ms->window.dictLimit;
     U32         const current = (U32)(ip-base);
     const BYTE* const dictBase = dms->window.base;
     const BYTE* const dictEnd = dms->window.nextSrc;
     U32         const dictHighLimit = (U32)(dms->window.nextSrc - dms->window.base);
     U32         const dictLowLimit = dms->window.lowLimit;
     U32         const dictIndexDelta = ms->window.lowLimit - dictHighLimit;
 
     U32*        const dictBt = dms->chainTable;
     U32         const btLog  = dmsCParams->chainLog - 1;
     U32         const btMask = (1 << btLog) - 1;
     U32         const btLow = (btMask >= dictHighLimit - dictLowLimit) ? dictLowLimit : dictHighLimit - btMask;
 
     size_t commonLengthSmaller=0, commonLengthLarger=0;
 
     (void)dictMode;
     assert(dictMode == ZSTD_dictMatchState);
 
     while (nbCompares-- && (dictMatchIndex > dictLowLimit)) {
         U32* const nextPtr = dictBt + 2*(dictMatchIndex & btMask);
         size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
         const BYTE* match = dictBase + dictMatchIndex;
         matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
         if (dictMatchIndex+matchLength >= dictHighLimit)
             match = base + dictMatchIndex + dictIndexDelta;   /* to prepare for next usage of match[matchLength] */
 
         if (matchLength > bestLength) {
             U32 matchIndex = dictMatchIndex + dictIndexDelta;
             if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) ) {
                 DEBUGLOG(9, "ZSTD_DUBT_findBetterDictMatch(%u) : found better match length %u -> %u and offsetCode %u -> %u (dictMatchIndex %u, matchIndex %u)",
                     current, (U32)bestLength, (U32)matchLength, (U32)*offsetPtr, ZSTD_REP_MOVE + current - matchIndex, dictMatchIndex, matchIndex);
                 bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex;
             }
             if (ip+matchLength == iend) {   /* reached end of input : ip[matchLength] is not valid, no way to know if it's larger or smaller than match */
                 break;   /* drop, to guarantee consistency (miss a little bit of compression) */
             }
         }
 
         if (match[matchLength] < ip[matchLength]) {
             if (dictMatchIndex <= btLow) { break; }   /* beyond tree size, stop the search */
             commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
             dictMatchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
         } else {
             /* match is larger than current */
             if (dictMatchIndex <= btLow) { break; }   /* beyond tree size, stop the search */
             commonLengthLarger = matchLength;
             dictMatchIndex = nextPtr[0];
         }
     }
 
     if (bestLength >= MINMATCH) {
         U32 const mIndex = current - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex;
         DEBUGLOG(8, "ZSTD_DUBT_findBetterDictMatch(%u) : found match of length %u and offsetCode %u (pos %u)",
                     current, (U32)bestLength, (U32)*offsetPtr, mIndex);
     }
     return bestLength;
 
 }
 
 
 static size_t
 ZSTD_DUBT_findBestMatch(ZSTD_matchState_t* ms,
                         const BYTE* const ip, const BYTE* const iend,
                         size_t* offsetPtr,
                         U32 const mls,
                         const ZSTD_dictMode_e dictMode)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32*   const hashTable = ms->hashTable;
     U32    const hashLog = cParams->hashLog;
     size_t const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32          matchIndex  = hashTable[h];
 
     const BYTE* const base = ms->window.base;
     U32    const current = (U32)(ip-base);
-    U32    const maxDistance = 1U << cParams->windowLog;
-    U32    const windowValid = ms->window.lowLimit;
-    U32    const windowLow = (current - windowValid > maxDistance) ? current - maxDistance : windowValid;
+    U32    const windowLow = ZSTD_getLowestMatchIndex(ms, current, cParams->windowLog);
 
     U32*   const bt = ms->chainTable;
     U32    const btLog  = cParams->chainLog - 1;
     U32    const btMask = (1 << btLog) - 1;
     U32    const btLow = (btMask >= current) ? 0 : current - btMask;
     U32    const unsortLimit = MAX(btLow, windowLow);
 
     U32*         nextCandidate = bt + 2*(matchIndex&btMask);
     U32*         unsortedMark = bt + 2*(matchIndex&btMask) + 1;
     U32          nbCompares = 1U << cParams->searchLog;
     U32          nbCandidates = nbCompares;
     U32          previousCandidate = 0;
 
     DEBUGLOG(7, "ZSTD_DUBT_findBestMatch (%u) ", current);
     assert(ip <= iend-8);   /* required for h calculation */
 
     /* reach end of unsorted candidates list */
     while ( (matchIndex > unsortLimit)
          && (*unsortedMark == ZSTD_DUBT_UNSORTED_MARK)
          && (nbCandidates > 1) ) {
         DEBUGLOG(8, "ZSTD_DUBT_findBestMatch: candidate %u is unsorted",
                     matchIndex);
         *unsortedMark = previousCandidate;  /* the unsortedMark becomes a reversed chain, to move up back to original position */
         previousCandidate = matchIndex;
         matchIndex = *nextCandidate;
         nextCandidate = bt + 2*(matchIndex&btMask);
         unsortedMark = bt + 2*(matchIndex&btMask) + 1;
         nbCandidates --;
     }
 
     /* nullify last candidate if it's still unsorted
      * simplification, detrimental to compression ratio, beneficial for speed */
     if ( (matchIndex > unsortLimit)
       && (*unsortedMark==ZSTD_DUBT_UNSORTED_MARK) ) {
         DEBUGLOG(7, "ZSTD_DUBT_findBestMatch: nullify last unsorted candidate %u",
                     matchIndex);
         *nextCandidate = *unsortedMark = 0;
     }
 
     /* batch sort stacked candidates */
     matchIndex = previousCandidate;
     while (matchIndex) {  /* will end on matchIndex == 0 */
         U32* const nextCandidateIdxPtr = bt + 2*(matchIndex&btMask) + 1;
         U32 const nextCandidateIdx = *nextCandidateIdxPtr;
         ZSTD_insertDUBT1(ms, matchIndex, iend,
                          nbCandidates, unsortLimit, dictMode);
         matchIndex = nextCandidateIdx;
         nbCandidates++;
     }
 
     /* find longest match */
     {   size_t commonLengthSmaller = 0, commonLengthLarger = 0;
         const BYTE* const dictBase = ms->window.dictBase;
         const U32 dictLimit = ms->window.dictLimit;
         const BYTE* const dictEnd = dictBase + dictLimit;
         const BYTE* const prefixStart = base + dictLimit;
         U32* smallerPtr = bt + 2*(current&btMask);
         U32* largerPtr  = bt + 2*(current&btMask) + 1;
         U32 matchEndIdx = current + 8 + 1;
         U32 dummy32;   /* to be nullified at the end */
         size_t bestLength = 0;
 
         matchIndex  = hashTable[h];
         hashTable[h] = current;   /* Update Hash Table */
 
         while (nbCompares-- && (matchIndex > windowLow)) {
             U32* const nextPtr = bt + 2*(matchIndex & btMask);
             size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
             const BYTE* match;
 
             if ((dictMode != ZSTD_extDict) || (matchIndex+matchLength >= dictLimit)) {
                 match = base + matchIndex;
                 matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
             } else {
                 match = dictBase + matchIndex;
                 matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
                 if (matchIndex+matchLength >= dictLimit)
                     match = base + matchIndex;   /* to prepare for next usage of match[matchLength] */
             }
 
             if (matchLength > bestLength) {
                 if (matchLength > matchEndIdx - matchIndex)
                     matchEndIdx = matchIndex + (U32)matchLength;
                 if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(current-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) )
                     bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + current - matchIndex;
                 if (ip+matchLength == iend) {   /* equal : no way to know if inf or sup */
                     if (dictMode == ZSTD_dictMatchState) {
                         nbCompares = 0; /* in addition to avoiding checking any
                                          * further in this loop, make sure we
                                          * skip checking in the dictionary. */
                     }
                     break;   /* drop, to guarantee consistency (miss a little bit of compression) */
                 }
             }
 
             if (match[matchLength] < ip[matchLength]) {
                 /* match is smaller than current */
                 *smallerPtr = matchIndex;             /* update smaller idx */
                 commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
                 if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
                 smallerPtr = nextPtr+1;               /* new "smaller" => larger of match */
                 matchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
             } else {
                 /* match is larger than current */
                 *largerPtr = matchIndex;
                 commonLengthLarger = matchLength;
                 if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
                 largerPtr = nextPtr;
                 matchIndex = nextPtr[0];
         }   }
 
         *smallerPtr = *largerPtr = 0;
 
         if (dictMode == ZSTD_dictMatchState && nbCompares) {
             bestLength = ZSTD_DUBT_findBetterDictMatch(
                     ms, ip, iend,
                     offsetPtr, bestLength, nbCompares,
                     mls, dictMode);
         }
 
         assert(matchEndIdx > current+8); /* ensure nextToUpdate is increased */
         ms->nextToUpdate = matchEndIdx - 8;   /* skip repetitive patterns */
         if (bestLength >= MINMATCH) {
             U32 const mIndex = current - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex;
             DEBUGLOG(8, "ZSTD_DUBT_findBestMatch(%u) : found match of length %u and offsetCode %u (pos %u)",
                         current, (U32)bestLength, (U32)*offsetPtr, mIndex);
         }
         return bestLength;
     }
 }
 
 
 /** ZSTD_BtFindBestMatch() : Tree updater, providing best match */
 FORCE_INLINE_TEMPLATE size_t
 ZSTD_BtFindBestMatch( ZSTD_matchState_t* ms,
                 const BYTE* const ip, const BYTE* const iLimit,
                       size_t* offsetPtr,
                 const U32 mls /* template */,
                 const ZSTD_dictMode_e dictMode)
 {
     DEBUGLOG(7, "ZSTD_BtFindBestMatch");
     if (ip < ms->window.base + ms->nextToUpdate) return 0;   /* skipped area */
     ZSTD_updateDUBT(ms, ip, iLimit, mls);
     return ZSTD_DUBT_findBestMatch(ms, ip, iLimit, offsetPtr, mls, dictMode);
 }
 
 
 static size_t
 ZSTD_BtFindBestMatch_selectMLS (  ZSTD_matchState_t* ms,
                             const BYTE* ip, const BYTE* const iLimit,
                                   size_t* offsetPtr)
 {
     switch(ms->cParams.minMatch)
     {
     default : /* includes case 3 */
     case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
     case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
     case 7 :
     case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
     }
 }
 
 
 static size_t ZSTD_BtFindBestMatch_dictMatchState_selectMLS (
                         ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr)
 {
     switch(ms->cParams.minMatch)
     {
     default : /* includes case 3 */
     case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
     case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
     case 7 :
     case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
     }
 }
 
 
 static size_t ZSTD_BtFindBestMatch_extDict_selectMLS (
                         ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr)
 {
     switch(ms->cParams.minMatch)
     {
     default : /* includes case 3 */
     case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
     case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
     case 7 :
     case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
     }
 }
 
 
 
 /* *********************************
 *  Hash Chain
 ***********************************/
 #define NEXT_IN_CHAIN(d, mask)   chainTable[(d) & (mask)]
 
 /* Update chains up to ip (excluded)
    Assumption : always within prefix (i.e. not within extDict) */
 static U32 ZSTD_insertAndFindFirstIndex_internal(
                         ZSTD_matchState_t* ms,
                         const ZSTD_compressionParameters* const cParams,
                         const BYTE* ip, U32 const mls)
 {
     U32* const hashTable  = ms->hashTable;
     const U32 hashLog = cParams->hashLog;
     U32* const chainTable = ms->chainTable;
     const U32 chainMask = (1 << cParams->chainLog) - 1;
     const BYTE* const base = ms->window.base;
     const U32 target = (U32)(ip - base);
     U32 idx = ms->nextToUpdate;
 
     while(idx < target) { /* catch up */
         size_t const h = ZSTD_hashPtr(base+idx, hashLog, mls);
         NEXT_IN_CHAIN(idx, chainMask) = hashTable[h];
         hashTable[h] = idx;
         idx++;
     }
 
     ms->nextToUpdate = target;
     return hashTable[ZSTD_hashPtr(ip, hashLog, mls)];
 }
 
 U32 ZSTD_insertAndFindFirstIndex(ZSTD_matchState_t* ms, const BYTE* ip) {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     return ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, ms->cParams.minMatch);
 }
 
 
 /* inlining is important to hardwire a hot branch (template emulation) */
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_HcFindBestMatch_generic (
                         ZSTD_matchState_t* ms,
                         const BYTE* const ip, const BYTE* const iLimit,
                         size_t* offsetPtr,
                         const U32 mls, const ZSTD_dictMode_e dictMode)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32* const chainTable = ms->chainTable;
     const U32 chainSize = (1 << cParams->chainLog);
     const U32 chainMask = chainSize-1;
     const BYTE* const base = ms->window.base;
     const BYTE* const dictBase = ms->window.dictBase;
     const U32 dictLimit = ms->window.dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const U32 current = (U32)(ip-base);
     const U32 maxDistance = 1U << cParams->windowLog;
-    const U32 lowValid = ms->window.lowLimit;
-    const U32 lowLimit = (current - lowValid > maxDistance) ? current - maxDistance : lowValid;
+    const U32 lowestValid = ms->window.lowLimit;
+    const U32 withinMaxDistance = (current - lowestValid > maxDistance) ? current - maxDistance : lowestValid;
+    const U32 isDictionary = (ms->loadedDictEnd != 0);
+    const U32 lowLimit = isDictionary ? lowestValid : withinMaxDistance;
     const U32 minChain = current > chainSize ? current - chainSize : 0;
     U32 nbAttempts = 1U << cParams->searchLog;
     size_t ml=4-1;
 
     /* HC4 match finder */
     U32 matchIndex = ZSTD_insertAndFindFirstIndex_internal(ms, cParams, ip, mls);
 
     for ( ; (matchIndex>lowLimit) & (nbAttempts>0) ; nbAttempts--) {
         size_t currentMl=0;
         if ((dictMode != ZSTD_extDict) || matchIndex >= dictLimit) {
             const BYTE* const match = base + matchIndex;
             assert(matchIndex >= dictLimit);   /* ensures this is true if dictMode != ZSTD_extDict */
             if (match[ml] == ip[ml])   /* potentially better */
                 currentMl = ZSTD_count(ip, match, iLimit);
         } else {
             const BYTE* const match = dictBase + matchIndex;
             assert(match+4 <= dictEnd);
             if (MEM_read32(match) == MEM_read32(ip))   /* assumption : matchIndex <= dictLimit-4 (by table construction) */
                 currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dictEnd, prefixStart) + 4;
         }
 
         /* save best solution */
         if (currentMl > ml) {
             ml = currentMl;
             *offsetPtr = current - matchIndex + ZSTD_REP_MOVE;
             if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
         }
 
         if (matchIndex <= minChain) break;
         matchIndex = NEXT_IN_CHAIN(matchIndex, chainMask);
     }
 
     if (dictMode == ZSTD_dictMatchState) {
         const ZSTD_matchState_t* const dms = ms->dictMatchState;
         const U32* const dmsChainTable = dms->chainTable;
         const U32 dmsChainSize         = (1 << dms->cParams.chainLog);
         const U32 dmsChainMask         = dmsChainSize - 1;
         const U32 dmsLowestIndex       = dms->window.dictLimit;
         const BYTE* const dmsBase      = dms->window.base;
         const BYTE* const dmsEnd       = dms->window.nextSrc;
         const U32 dmsSize              = (U32)(dmsEnd - dmsBase);
         const U32 dmsIndexDelta        = dictLimit - dmsSize;
         const U32 dmsMinChain = dmsSize > dmsChainSize ? dmsSize - dmsChainSize : 0;
 
         matchIndex = dms->hashTable[ZSTD_hashPtr(ip, dms->cParams.hashLog, mls)];
 
         for ( ; (matchIndex>dmsLowestIndex) & (nbAttempts>0) ; nbAttempts--) {
             size_t currentMl=0;
             const BYTE* const match = dmsBase + matchIndex;
             assert(match+4 <= dmsEnd);
             if (MEM_read32(match) == MEM_read32(ip))   /* assumption : matchIndex <= dictLimit-4 (by table construction) */
                 currentMl = ZSTD_count_2segments(ip+4, match+4, iLimit, dmsEnd, prefixStart) + 4;
 
             /* save best solution */
             if (currentMl > ml) {
                 ml = currentMl;
                 *offsetPtr = current - (matchIndex + dmsIndexDelta) + ZSTD_REP_MOVE;
                 if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
             }
 
             if (matchIndex <= dmsMinChain) break;
             matchIndex = dmsChainTable[matchIndex & dmsChainMask];
         }
     }
 
     return ml;
 }
 
 
 FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_selectMLS (
                         ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr)
 {
     switch(ms->cParams.minMatch)
     {
     default : /* includes case 3 */
     case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
     case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
     case 7 :
     case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
     }
 }
 
 
 static size_t ZSTD_HcFindBestMatch_dictMatchState_selectMLS (
                         ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr)
 {
     switch(ms->cParams.minMatch)
     {
     default : /* includes case 3 */
     case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
     case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
     case 7 :
     case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
     }
 }
 
 
 FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_extDict_selectMLS (
                         ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* const iLimit,
                         size_t* offsetPtr)
 {
     switch(ms->cParams.minMatch)
     {
     default : /* includes case 3 */
     case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
     case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
     case 7 :
     case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
     }
 }
 
 
 /* *******************************
 *  Common parser - lazy strategy
 *********************************/
-FORCE_INLINE_TEMPLATE
-size_t ZSTD_compressBlock_lazy_generic(
+typedef enum { search_hashChain, search_binaryTree } searchMethod_e;
+
+FORCE_INLINE_TEMPLATE size_t
+ZSTD_compressBlock_lazy_generic(
                         ZSTD_matchState_t* ms, seqStore_t* seqStore,
                         U32 rep[ZSTD_REP_NUM],
                         const void* src, size_t srcSize,
-                        const U32 searchMethod, const U32 depth,
+                        const searchMethod_e searchMethod, const U32 depth,
                         ZSTD_dictMode_e const dictMode)
 {
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
     const BYTE* const base = ms->window.base;
     const U32 prefixLowestIndex = ms->window.dictLimit;
     const BYTE* const prefixLowest = base + prefixLowestIndex;
 
     typedef size_t (*searchMax_f)(
                         ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
     searchMax_f const searchMax = dictMode == ZSTD_dictMatchState ?
-        (searchMethod ? ZSTD_BtFindBestMatch_dictMatchState_selectMLS : ZSTD_HcFindBestMatch_dictMatchState_selectMLS) :
-        (searchMethod ? ZSTD_BtFindBestMatch_selectMLS : ZSTD_HcFindBestMatch_selectMLS);
+        (searchMethod==search_binaryTree ? ZSTD_BtFindBestMatch_dictMatchState_selectMLS
+                                         : ZSTD_HcFindBestMatch_dictMatchState_selectMLS) :
+        (searchMethod==search_binaryTree ? ZSTD_BtFindBestMatch_selectMLS
+                                         : ZSTD_HcFindBestMatch_selectMLS);
     U32 offset_1 = rep[0], offset_2 = rep[1], savedOffset=0;
 
     const ZSTD_matchState_t* const dms = ms->dictMatchState;
     const U32 dictLowestIndex      = dictMode == ZSTD_dictMatchState ?
                                      dms->window.dictLimit : 0;
     const BYTE* const dictBase     = dictMode == ZSTD_dictMatchState ?
                                      dms->window.base : NULL;
     const BYTE* const dictLowest   = dictMode == ZSTD_dictMatchState ?
                                      dictBase + dictLowestIndex : NULL;
     const BYTE* const dictEnd      = dictMode == ZSTD_dictMatchState ?
                                      dms->window.nextSrc : NULL;
     const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
                                      prefixLowestIndex - (U32)(dictEnd - dictBase) :
                                      0;
     const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictLowest);
 
     /* init */
     ip += (dictAndPrefixLength == 0);
     if (dictMode == ZSTD_noDict) {
         U32 const maxRep = (U32)(ip - prefixLowest);
         if (offset_2 > maxRep) savedOffset = offset_2, offset_2 = 0;
         if (offset_1 > maxRep) savedOffset = offset_1, offset_1 = 0;
     }
     if (dictMode == ZSTD_dictMatchState) {
         /* dictMatchState repCode checks don't currently handle repCode == 0
          * disabling. */
         assert(offset_1 <= dictAndPrefixLength);
         assert(offset_2 <= dictAndPrefixLength);
     }
 
     /* Match Loop */
     while (ip < ilimit) {
         size_t matchLength=0;
         size_t offset=0;
         const BYTE* start=ip+1;
 
         /* check repCode */
         if (dictMode == ZSTD_dictMatchState) {
             const U32 repIndex = (U32)(ip - base) + 1 - offset_1;
             const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
                                 && repIndex < prefixLowestIndex) ?
                                    dictBase + (repIndex - dictIndexDelta) :
                                    base + repIndex;
             if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
                 && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
                 const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
                 matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
                 if (depth==0) goto _storeSequence;
             }
         }
         if ( dictMode == ZSTD_noDict
           && ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
             matchLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
             if (depth==0) goto _storeSequence;
         }
 
         /* first search (depth 0) */
         {   size_t offsetFound = 999999999;
             size_t const ml2 = searchMax(ms, ip, iend, &offsetFound);
             if (ml2 > matchLength)
                 matchLength = ml2, start = ip, offset=offsetFound;
         }
 
         if (matchLength < 4) {
             ip += ((ip-anchor) >> kSearchStrength) + 1;   /* jump faster over incompressible sections */
             continue;
         }
 
         /* let's try to find a better solution */
         if (depth>=1)
         while (ip0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
                 size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
                 int const gain2 = (int)(mlRep * 3);
                 int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
                 if ((mlRep >= 4) && (gain2 > gain1))
                     matchLength = mlRep, offset = 0, start = ip;
             }
             if (dictMode == ZSTD_dictMatchState) {
                 const U32 repIndex = (U32)(ip - base) - offset_1;
                 const BYTE* repMatch = repIndex < prefixLowestIndex ?
                                dictBase + (repIndex - dictIndexDelta) :
                                base + repIndex;
                 if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
                     && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
                     const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
                     size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
                     int const gain2 = (int)(mlRep * 3);
                     int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
                     if ((mlRep >= 4) && (gain2 > gain1))
                         matchLength = mlRep, offset = 0, start = ip;
                 }
             }
             {   size_t offset2=999999999;
                 size_t const ml2 = searchMax(ms, ip, iend, &offset2);
                 int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1));   /* raw approx */
                 int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
                 if ((ml2 >= 4) && (gain2 > gain1)) {
                     matchLength = ml2, offset = offset2, start = ip;
                     continue;   /* search a better one */
             }   }
 
             /* let's find an even better one */
             if ((depth==2) && (ip0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
                     size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
                     int const gain2 = (int)(mlRep * 4);
                     int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
                     if ((mlRep >= 4) && (gain2 > gain1))
                         matchLength = mlRep, offset = 0, start = ip;
                 }
                 if (dictMode == ZSTD_dictMatchState) {
                     const U32 repIndex = (U32)(ip - base) - offset_1;
                     const BYTE* repMatch = repIndex < prefixLowestIndex ?
                                    dictBase + (repIndex - dictIndexDelta) :
                                    base + repIndex;
                     if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
                         && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
                         const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
                         size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
                         int const gain2 = (int)(mlRep * 4);
                         int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
                         if ((mlRep >= 4) && (gain2 > gain1))
                             matchLength = mlRep, offset = 0, start = ip;
                     }
                 }
                 {   size_t offset2=999999999;
                     size_t const ml2 = searchMax(ms, ip, iend, &offset2);
                     int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1));   /* raw approx */
                     int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
                     if ((ml2 >= 4) && (gain2 > gain1)) {
                         matchLength = ml2, offset = offset2, start = ip;
                         continue;
             }   }   }
             break;  /* nothing found : store previous solution */
         }
 
         /* NOTE:
          * start[-offset+ZSTD_REP_MOVE-1] is undefined behavior.
          * (-offset+ZSTD_REP_MOVE-1) is unsigned, and is added to start, which
          * overflows the pointer, which is undefined behavior.
          */
         /* catch up */
         if (offset) {
             if (dictMode == ZSTD_noDict) {
                 while ( ((start > anchor) & (start - (offset-ZSTD_REP_MOVE) > prefixLowest))
                      && (start[-1] == (start-(offset-ZSTD_REP_MOVE))[-1]) )  /* only search for offset within prefix */
                     { start--; matchLength++; }
             }
             if (dictMode == ZSTD_dictMatchState) {
                 U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
                 const BYTE* match = (matchIndex < prefixLowestIndex) ? dictBase + matchIndex - dictIndexDelta : base + matchIndex;
                 const BYTE* const mStart = (matchIndex < prefixLowestIndex) ? dictLowest : prefixLowest;
                 while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; }  /* catch up */
             }
             offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
         }
         /* store sequence */
 _storeSequence:
         {   size_t const litLength = start - anchor;
-            ZSTD_storeSeq(seqStore, litLength, anchor, (U32)offset, matchLength-MINMATCH);
+            ZSTD_storeSeq(seqStore, litLength, anchor, iend, (U32)offset, matchLength-MINMATCH);
             anchor = ip = start + matchLength;
         }
 
         /* check immediate repcode */
         if (dictMode == ZSTD_dictMatchState) {
             while (ip <= ilimit) {
                 U32 const current2 = (U32)(ip-base);
                 U32 const repIndex = current2 - offset_2;
                 const BYTE* repMatch = dictMode == ZSTD_dictMatchState
                     && repIndex < prefixLowestIndex ?
                         dictBase - dictIndexDelta + repIndex :
                         base + repIndex;
                 if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex) >= 3 /* intentional overflow */)
                    && (MEM_read32(repMatch) == MEM_read32(ip)) ) {
                     const BYTE* const repEnd2 = repIndex < prefixLowestIndex ? dictEnd : iend;
                     matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd2, prefixLowest) + 4;
                     offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset;   /* swap offset_2 <=> offset_1 */
-                    ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
+                    ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
                     ip += matchLength;
                     anchor = ip;
                     continue;
                 }
                 break;
             }
         }
 
         if (dictMode == ZSTD_noDict) {
             while ( ((ip <= ilimit) & (offset_2>0))
                  && (MEM_read32(ip) == MEM_read32(ip - offset_2)) ) {
                 /* store sequence */
                 matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
                 offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
-                ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
+                ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
                 ip += matchLength;
                 anchor = ip;
                 continue;   /* faster when present ... (?) */
     }   }   }
 
     /* Save reps for next block */
     rep[0] = offset_1 ? offset_1 : savedOffset;
     rep[1] = offset_2 ? offset_2 : savedOffset;
 
     /* Return the last literals size */
-    return iend - anchor;
+    return (size_t)(iend - anchor);
 }
 
 
 size_t ZSTD_compressBlock_btlazy2(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 1, 2, ZSTD_noDict);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_binaryTree, 2, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_lazy2(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 2, ZSTD_noDict);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 2, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_lazy(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 1, ZSTD_noDict);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 1, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_greedy(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 0, ZSTD_noDict);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 0, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_btlazy2_dictMatchState(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 1, 2, ZSTD_dictMatchState);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_binaryTree, 2, ZSTD_dictMatchState);
 }
 
 size_t ZSTD_compressBlock_lazy2_dictMatchState(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 2, ZSTD_dictMatchState);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 2, ZSTD_dictMatchState);
 }
 
 size_t ZSTD_compressBlock_lazy_dictMatchState(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 1, ZSTD_dictMatchState);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 1, ZSTD_dictMatchState);
 }
 
 size_t ZSTD_compressBlock_greedy_dictMatchState(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, 0, 0, ZSTD_dictMatchState);
+    return ZSTD_compressBlock_lazy_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 0, ZSTD_dictMatchState);
 }
 
 
 FORCE_INLINE_TEMPLATE
 size_t ZSTD_compressBlock_lazy_extDict_generic(
                         ZSTD_matchState_t* ms, seqStore_t* seqStore,
                         U32 rep[ZSTD_REP_NUM],
                         const void* src, size_t srcSize,
-                        const U32 searchMethod, const U32 depth)
+                        const searchMethod_e searchMethod, const U32 depth)
 {
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
     const BYTE* const base = ms->window.base;
     const U32 dictLimit = ms->window.dictLimit;
     const U32 lowestIndex = ms->window.lowLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* const dictBase = ms->window.dictBase;
     const BYTE* const dictEnd  = dictBase + dictLimit;
     const BYTE* const dictStart  = dictBase + lowestIndex;
 
     typedef size_t (*searchMax_f)(
                         ZSTD_matchState_t* ms,
                         const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
-    searchMax_f searchMax = searchMethod ? ZSTD_BtFindBestMatch_extDict_selectMLS : ZSTD_HcFindBestMatch_extDict_selectMLS;
+    searchMax_f searchMax = searchMethod==search_binaryTree ? ZSTD_BtFindBestMatch_extDict_selectMLS : ZSTD_HcFindBestMatch_extDict_selectMLS;
 
     U32 offset_1 = rep[0], offset_2 = rep[1];
 
     /* init */
     ip += (ip == prefixStart);
 
     /* Match Loop */
     while (ip < ilimit) {
         size_t matchLength=0;
         size_t offset=0;
         const BYTE* start=ip+1;
         U32 current = (U32)(ip-base);
 
         /* check repCode */
         {   const U32 repIndex = (U32)(current+1 - offset_1);
             const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
             const BYTE* const repMatch = repBase + repIndex;
             if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex))   /* intentional overflow */
             if (MEM_read32(ip+1) == MEM_read32(repMatch)) {
                 /* repcode detected we should take it */
                 const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                 matchLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repEnd, prefixStart) + 4;
                 if (depth==0) goto _storeSequence;
         }   }
 
         /* first search (depth 0) */
         {   size_t offsetFound = 999999999;
             size_t const ml2 = searchMax(ms, ip, iend, &offsetFound);
             if (ml2 > matchLength)
                 matchLength = ml2, start = ip, offset=offsetFound;
         }
 
          if (matchLength < 4) {
             ip += ((ip-anchor) >> kSearchStrength) + 1;   /* jump faster over incompressible sections */
             continue;
         }
 
         /* let's try to find a better solution */
         if (depth>=1)
         while (ip= 3) & (repIndex > lowestIndex))  /* intentional overflow */
                 if (MEM_read32(ip) == MEM_read32(repMatch)) {
                     /* repcode detected */
                     const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                     size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
                     int const gain2 = (int)(repLength * 3);
                     int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
                     if ((repLength >= 4) && (gain2 > gain1))
                         matchLength = repLength, offset = 0, start = ip;
             }   }
 
             /* search match, depth 1 */
             {   size_t offset2=999999999;
                 size_t const ml2 = searchMax(ms, ip, iend, &offset2);
                 int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1));   /* raw approx */
                 int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
                 if ((ml2 >= 4) && (gain2 > gain1)) {
                     matchLength = ml2, offset = offset2, start = ip;
                     continue;   /* search a better one */
             }   }
 
             /* let's find an even better one */
             if ((depth==2) && (ip= 3) & (repIndex > lowestIndex))  /* intentional overflow */
                     if (MEM_read32(ip) == MEM_read32(repMatch)) {
                         /* repcode detected */
                         const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                         size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
                         int const gain2 = (int)(repLength * 4);
                         int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
                         if ((repLength >= 4) && (gain2 > gain1))
                             matchLength = repLength, offset = 0, start = ip;
                 }   }
 
                 /* search match, depth 2 */
                 {   size_t offset2=999999999;
                     size_t const ml2 = searchMax(ms, ip, iend, &offset2);
                     int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1));   /* raw approx */
                     int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
                     if ((ml2 >= 4) && (gain2 > gain1)) {
                         matchLength = ml2, offset = offset2, start = ip;
                         continue;
             }   }   }
             break;  /* nothing found : store previous solution */
         }
 
         /* catch up */
         if (offset) {
             U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
             const BYTE* match = (matchIndex < dictLimit) ? dictBase + matchIndex : base + matchIndex;
             const BYTE* const mStart = (matchIndex < dictLimit) ? dictStart : prefixStart;
             while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; }  /* catch up */
             offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
         }
 
         /* store sequence */
 _storeSequence:
         {   size_t const litLength = start - anchor;
-            ZSTD_storeSeq(seqStore, litLength, anchor, (U32)offset, matchLength-MINMATCH);
+            ZSTD_storeSeq(seqStore, litLength, anchor, iend, (U32)offset, matchLength-MINMATCH);
             anchor = ip = start + matchLength;
         }
 
         /* check immediate repcode */
         while (ip <= ilimit) {
             const U32 repIndex = (U32)((ip-base) - offset_2);
             const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
             const BYTE* const repMatch = repBase + repIndex;
             if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > lowestIndex))  /* intentional overflow */
             if (MEM_read32(ip) == MEM_read32(repMatch)) {
                 /* repcode detected we should take it */
                 const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
                 matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
                 offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset;   /* swap offset history */
-                ZSTD_storeSeq(seqStore, 0, anchor, 0, matchLength-MINMATCH);
+                ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
                 ip += matchLength;
                 anchor = ip;
                 continue;   /* faster when present ... (?) */
             }
             break;
     }   }
 
     /* Save reps for next block */
     rep[0] = offset_1;
     rep[1] = offset_2;
 
     /* Return the last literals size */
-    return iend - anchor;
+    return (size_t)(iend - anchor);
 }
 
 
 size_t ZSTD_compressBlock_greedy_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 {
-    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 0);
+    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 0);
 }
 
 size_t ZSTD_compressBlock_lazy_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 
 {
-    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 1);
+    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 1);
 }
 
 size_t ZSTD_compressBlock_lazy2_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 
 {
-    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 0, 2);
+    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, search_hashChain, 2);
 }
 
 size_t ZSTD_compressBlock_btlazy2_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         void const* src, size_t srcSize)
 
 {
-    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, 1, 2);
+    return ZSTD_compressBlock_lazy_extDict_generic(ms, seqStore, rep, src, srcSize, search_binaryTree, 2);
 }
Index: head/sys/contrib/zstd/lib/compress/zstd_ldm.c
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_ldm.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_ldm.c	(revision 354777)
@@ -1,597 +1,597 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  */
 
 #include "zstd_ldm.h"
 
 #include "debug.h"
 #include "zstd_fast.h"          /* ZSTD_fillHashTable() */
 #include "zstd_double_fast.h"   /* ZSTD_fillDoubleHashTable() */
 
 #define LDM_BUCKET_SIZE_LOG 3
 #define LDM_MIN_MATCH_LENGTH 64
 #define LDM_HASH_RLOG 7
 #define LDM_HASH_CHAR_OFFSET 10
 
 void ZSTD_ldm_adjustParameters(ldmParams_t* params,
                                ZSTD_compressionParameters const* cParams)
 {
     params->windowLog = cParams->windowLog;
     ZSTD_STATIC_ASSERT(LDM_BUCKET_SIZE_LOG <= ZSTD_LDM_BUCKETSIZELOG_MAX);
     DEBUGLOG(4, "ZSTD_ldm_adjustParameters");
     if (!params->bucketSizeLog) params->bucketSizeLog = LDM_BUCKET_SIZE_LOG;
     if (!params->minMatchLength) params->minMatchLength = LDM_MIN_MATCH_LENGTH;
     if (cParams->strategy >= ZSTD_btopt) {
       /* Get out of the way of the optimal parser */
       U32 const minMatch = MAX(cParams->targetLength, params->minMatchLength);
       assert(minMatch >= ZSTD_LDM_MINMATCH_MIN);
       assert(minMatch <= ZSTD_LDM_MINMATCH_MAX);
       params->minMatchLength = minMatch;
     }
     if (params->hashLog == 0) {
         params->hashLog = MAX(ZSTD_HASHLOG_MIN, params->windowLog - LDM_HASH_RLOG);
         assert(params->hashLog <= ZSTD_HASHLOG_MAX);
     }
     if (params->hashRateLog == 0) {
         params->hashRateLog = params->windowLog < params->hashLog
                                    ? 0
                                    : params->windowLog - params->hashLog;
     }
     params->bucketSizeLog = MIN(params->bucketSizeLog, params->hashLog);
 }
 
 size_t ZSTD_ldm_getTableSize(ldmParams_t params)
 {
     size_t const ldmHSize = ((size_t)1) << params.hashLog;
     size_t const ldmBucketSizeLog = MIN(params.bucketSizeLog, params.hashLog);
-    size_t const ldmBucketSize =
-        ((size_t)1) << (params.hashLog - ldmBucketSizeLog);
-    size_t const totalSize = ldmBucketSize + ldmHSize * sizeof(ldmEntry_t);
+    size_t const ldmBucketSize = ((size_t)1) << (params.hashLog - ldmBucketSizeLog);
+    size_t const totalSize = ZSTD_cwksp_alloc_size(ldmBucketSize)
+                           + ZSTD_cwksp_alloc_size(ldmHSize * sizeof(ldmEntry_t));
     return params.enableLdm ? totalSize : 0;
 }
 
 size_t ZSTD_ldm_getMaxNbSeq(ldmParams_t params, size_t maxChunkSize)
 {
     return params.enableLdm ? (maxChunkSize / params.minMatchLength) : 0;
 }
 
 /** ZSTD_ldm_getSmallHash() :
  *  numBits should be <= 32
  *  If numBits==0, returns 0.
  *  @return : the most significant numBits of value. */
 static U32 ZSTD_ldm_getSmallHash(U64 value, U32 numBits)
 {
     assert(numBits <= 32);
     return numBits == 0 ? 0 : (U32)(value >> (64 - numBits));
 }
 
 /** ZSTD_ldm_getChecksum() :
  *  numBitsToDiscard should be <= 32
  *  @return : the next most significant 32 bits after numBitsToDiscard */
 static U32 ZSTD_ldm_getChecksum(U64 hash, U32 numBitsToDiscard)
 {
     assert(numBitsToDiscard <= 32);
     return (hash >> (64 - 32 - numBitsToDiscard)) & 0xFFFFFFFF;
 }
 
 /** ZSTD_ldm_getTag() ;
  *  Given the hash, returns the most significant numTagBits bits
  *  after (32 + hbits) bits.
  *
  *  If there are not enough bits remaining, return the last
  *  numTagBits bits. */
 static U32 ZSTD_ldm_getTag(U64 hash, U32 hbits, U32 numTagBits)
 {
     assert(numTagBits < 32 && hbits <= 32);
     if (32 - hbits < numTagBits) {
         return hash & (((U32)1 << numTagBits) - 1);
     } else {
         return (hash >> (32 - hbits - numTagBits)) & (((U32)1 << numTagBits) - 1);
     }
 }
 
 /** ZSTD_ldm_getBucket() :
  *  Returns a pointer to the start of the bucket associated with hash. */
 static ldmEntry_t* ZSTD_ldm_getBucket(
         ldmState_t* ldmState, size_t hash, ldmParams_t const ldmParams)
 {
     return ldmState->hashTable + (hash << ldmParams.bucketSizeLog);
 }
 
 /** ZSTD_ldm_insertEntry() :
  *  Insert the entry with corresponding hash into the hash table */
 static void ZSTD_ldm_insertEntry(ldmState_t* ldmState,
                                  size_t const hash, const ldmEntry_t entry,
                                  ldmParams_t const ldmParams)
 {
     BYTE* const bucketOffsets = ldmState->bucketOffsets;
     *(ZSTD_ldm_getBucket(ldmState, hash, ldmParams) + bucketOffsets[hash]) = entry;
     bucketOffsets[hash]++;
     bucketOffsets[hash] &= ((U32)1 << ldmParams.bucketSizeLog) - 1;
 }
 
 /** ZSTD_ldm_makeEntryAndInsertByTag() :
  *
  *  Gets the small hash, checksum, and tag from the rollingHash.
  *
  *  If the tag matches (1 << ldmParams.hashRateLog)-1, then
  *  creates an ldmEntry from the offset, and inserts it into the hash table.
  *
  *  hBits is the length of the small hash, which is the most significant hBits
  *  of rollingHash. The checksum is the next 32 most significant bits, followed
  *  by ldmParams.hashRateLog bits that make up the tag. */
 static void ZSTD_ldm_makeEntryAndInsertByTag(ldmState_t* ldmState,
                                              U64 const rollingHash,
                                              U32 const hBits,
                                              U32 const offset,
                                              ldmParams_t const ldmParams)
 {
     U32 const tag = ZSTD_ldm_getTag(rollingHash, hBits, ldmParams.hashRateLog);
     U32 const tagMask = ((U32)1 << ldmParams.hashRateLog) - 1;
     if (tag == tagMask) {
         U32 const hash = ZSTD_ldm_getSmallHash(rollingHash, hBits);
         U32 const checksum = ZSTD_ldm_getChecksum(rollingHash, hBits);
         ldmEntry_t entry;
         entry.offset = offset;
         entry.checksum = checksum;
         ZSTD_ldm_insertEntry(ldmState, hash, entry, ldmParams);
     }
 }
 
 /** ZSTD_ldm_countBackwardsMatch() :
  *  Returns the number of bytes that match backwards before pIn and pMatch.
  *
  *  We count only bytes where pMatch >= pBase and pIn >= pAnchor. */
 static size_t ZSTD_ldm_countBackwardsMatch(
             const BYTE* pIn, const BYTE* pAnchor,
             const BYTE* pMatch, const BYTE* pBase)
 {
     size_t matchLength = 0;
     while (pIn > pAnchor && pMatch > pBase && pIn[-1] == pMatch[-1]) {
         pIn--;
         pMatch--;
         matchLength++;
     }
     return matchLength;
 }
 
 /** ZSTD_ldm_fillFastTables() :
  *
  *  Fills the relevant tables for the ZSTD_fast and ZSTD_dfast strategies.
  *  This is similar to ZSTD_loadDictionaryContent.
  *
  *  The tables for the other strategies are filled within their
  *  block compressors. */
 static size_t ZSTD_ldm_fillFastTables(ZSTD_matchState_t* ms,
                                       void const* end)
 {
     const BYTE* const iend = (const BYTE*)end;
 
     switch(ms->cParams.strategy)
     {
     case ZSTD_fast:
         ZSTD_fillHashTable(ms, iend, ZSTD_dtlm_fast);
         break;
 
     case ZSTD_dfast:
         ZSTD_fillDoubleHashTable(ms, iend, ZSTD_dtlm_fast);
         break;
 
     case ZSTD_greedy:
     case ZSTD_lazy:
     case ZSTD_lazy2:
     case ZSTD_btlazy2:
     case ZSTD_btopt:
     case ZSTD_btultra:
     case ZSTD_btultra2:
         break;
     default:
         assert(0);  /* not possible : not a valid strategy id */
     }
 
     return 0;
 }
 
 /** ZSTD_ldm_fillLdmHashTable() :
  *
  *  Fills hashTable from (lastHashed + 1) to iend (non-inclusive).
  *  lastHash is the rolling hash that corresponds to lastHashed.
  *
  *  Returns the rolling hash corresponding to position iend-1. */
 static U64 ZSTD_ldm_fillLdmHashTable(ldmState_t* state,
                                      U64 lastHash, const BYTE* lastHashed,
                                      const BYTE* iend, const BYTE* base,
                                      U32 hBits, ldmParams_t const ldmParams)
 {
     U64 rollingHash = lastHash;
     const BYTE* cur = lastHashed + 1;
 
     while (cur < iend) {
         rollingHash = ZSTD_rollingHash_rotate(rollingHash, cur[-1],
                                               cur[ldmParams.minMatchLength-1],
                                               state->hashPower);
         ZSTD_ldm_makeEntryAndInsertByTag(state,
                                          rollingHash, hBits,
                                          (U32)(cur - base), ldmParams);
         ++cur;
     }
     return rollingHash;
 }
 
 
 /** ZSTD_ldm_limitTableUpdate() :
  *
  *  Sets cctx->nextToUpdate to a position corresponding closer to anchor
  *  if it is far way
  *  (after a long match, only update tables a limited amount). */
 static void ZSTD_ldm_limitTableUpdate(ZSTD_matchState_t* ms, const BYTE* anchor)
 {
     U32 const current = (U32)(anchor - ms->window.base);
     if (current > ms->nextToUpdate + 1024) {
         ms->nextToUpdate =
             current - MIN(512, current - ms->nextToUpdate - 1024);
     }
 }
 
 static size_t ZSTD_ldm_generateSequences_internal(
         ldmState_t* ldmState, rawSeqStore_t* rawSeqStore,
         ldmParams_t const* params, void const* src, size_t srcSize)
 {
     /* LDM parameters */
     int const extDict = ZSTD_window_hasExtDict(ldmState->window);
     U32 const minMatchLength = params->minMatchLength;
     U64 const hashPower = ldmState->hashPower;
     U32 const hBits = params->hashLog - params->bucketSizeLog;
     U32 const ldmBucketSize = 1U << params->bucketSizeLog;
     U32 const hashRateLog = params->hashRateLog;
     U32 const ldmTagMask = (1U << params->hashRateLog) - 1;
     /* Prefix and extDict parameters */
     U32 const dictLimit = ldmState->window.dictLimit;
     U32 const lowestIndex = extDict ? ldmState->window.lowLimit : dictLimit;
     BYTE const* const base = ldmState->window.base;
     BYTE const* const dictBase = extDict ? ldmState->window.dictBase : NULL;
     BYTE const* const dictStart = extDict ? dictBase + lowestIndex : NULL;
     BYTE const* const dictEnd = extDict ? dictBase + dictLimit : NULL;
     BYTE const* const lowPrefixPtr = base + dictLimit;
     /* Input bounds */
     BYTE const* const istart = (BYTE const*)src;
     BYTE const* const iend = istart + srcSize;
     BYTE const* const ilimit = iend - MAX(minMatchLength, HASH_READ_SIZE);
     /* Input positions */
     BYTE const* anchor = istart;
     BYTE const* ip = istart;
     /* Rolling hash */
     BYTE const* lastHashed = NULL;
     U64 rollingHash = 0;
 
     while (ip <= ilimit) {
         size_t mLength;
         U32 const current = (U32)(ip - base);
         size_t forwardMatchLength = 0, backwardMatchLength = 0;
         ldmEntry_t* bestEntry = NULL;
         if (ip != istart) {
             rollingHash = ZSTD_rollingHash_rotate(rollingHash, lastHashed[0],
                                                   lastHashed[minMatchLength],
                                                   hashPower);
         } else {
             rollingHash = ZSTD_rollingHash_compute(ip, minMatchLength);
         }
         lastHashed = ip;
 
         /* Do not insert and do not look for a match */
         if (ZSTD_ldm_getTag(rollingHash, hBits, hashRateLog) != ldmTagMask) {
            ip++;
            continue;
         }
 
         /* Get the best entry and compute the match lengths */
         {
             ldmEntry_t* const bucket =
                 ZSTD_ldm_getBucket(ldmState,
                                    ZSTD_ldm_getSmallHash(rollingHash, hBits),
                                    *params);
             ldmEntry_t* cur;
             size_t bestMatchLength = 0;
             U32 const checksum = ZSTD_ldm_getChecksum(rollingHash, hBits);
 
             for (cur = bucket; cur < bucket + ldmBucketSize; ++cur) {
                 size_t curForwardMatchLength, curBackwardMatchLength,
                        curTotalMatchLength;
                 if (cur->checksum != checksum || cur->offset <= lowestIndex) {
                     continue;
                 }
                 if (extDict) {
                     BYTE const* const curMatchBase =
                         cur->offset < dictLimit ? dictBase : base;
                     BYTE const* const pMatch = curMatchBase + cur->offset;
                     BYTE const* const matchEnd =
                         cur->offset < dictLimit ? dictEnd : iend;
                     BYTE const* const lowMatchPtr =
                         cur->offset < dictLimit ? dictStart : lowPrefixPtr;
 
                     curForwardMatchLength = ZSTD_count_2segments(
                                                 ip, pMatch, iend,
                                                 matchEnd, lowPrefixPtr);
                     if (curForwardMatchLength < minMatchLength) {
                         continue;
                     }
                     curBackwardMatchLength =
                         ZSTD_ldm_countBackwardsMatch(ip, anchor, pMatch,
                                                      lowMatchPtr);
                     curTotalMatchLength = curForwardMatchLength +
                                           curBackwardMatchLength;
                 } else { /* !extDict */
                     BYTE const* const pMatch = base + cur->offset;
                     curForwardMatchLength = ZSTD_count(ip, pMatch, iend);
                     if (curForwardMatchLength < minMatchLength) {
                         continue;
                     }
                     curBackwardMatchLength =
                         ZSTD_ldm_countBackwardsMatch(ip, anchor, pMatch,
                                                      lowPrefixPtr);
                     curTotalMatchLength = curForwardMatchLength +
                                           curBackwardMatchLength;
                 }
 
                 if (curTotalMatchLength > bestMatchLength) {
                     bestMatchLength = curTotalMatchLength;
                     forwardMatchLength = curForwardMatchLength;
                     backwardMatchLength = curBackwardMatchLength;
                     bestEntry = cur;
                 }
             }
         }
 
         /* No match found -- continue searching */
         if (bestEntry == NULL) {
             ZSTD_ldm_makeEntryAndInsertByTag(ldmState, rollingHash,
                                              hBits, current,
                                              *params);
             ip++;
             continue;
         }
 
         /* Match found */
         mLength = forwardMatchLength + backwardMatchLength;
         ip -= backwardMatchLength;
 
         {
             /* Store the sequence:
              * ip = current - backwardMatchLength
              * The match is at (bestEntry->offset - backwardMatchLength)
              */
             U32 const matchIndex = bestEntry->offset;
             U32 const offset = current - matchIndex;
             rawSeq* const seq = rawSeqStore->seq + rawSeqStore->size;
 
             /* Out of sequence storage */
             if (rawSeqStore->size == rawSeqStore->capacity)
                 return ERROR(dstSize_tooSmall);
             seq->litLength = (U32)(ip - anchor);
             seq->matchLength = (U32)mLength;
             seq->offset = offset;
             rawSeqStore->size++;
         }
 
         /* Insert the current entry into the hash table */
         ZSTD_ldm_makeEntryAndInsertByTag(ldmState, rollingHash, hBits,
                                          (U32)(lastHashed - base),
                                          *params);
 
         assert(ip + backwardMatchLength == lastHashed);
 
         /* Fill the hash table from lastHashed+1 to ip+mLength*/
         /* Heuristic: don't need to fill the entire table at end of block */
         if (ip + mLength <= ilimit) {
             rollingHash = ZSTD_ldm_fillLdmHashTable(
                               ldmState, rollingHash, lastHashed,
                               ip + mLength, base, hBits, *params);
             lastHashed = ip + mLength - 1;
         }
         ip += mLength;
         anchor = ip;
     }
     return iend - anchor;
 }
 
 /*! ZSTD_ldm_reduceTable() :
  *  reduce table indexes by `reducerValue` */
 static void ZSTD_ldm_reduceTable(ldmEntry_t* const table, U32 const size,
                                  U32 const reducerValue)
 {
     U32 u;
     for (u = 0; u < size; u++) {
         if (table[u].offset < reducerValue) table[u].offset = 0;
         else table[u].offset -= reducerValue;
     }
 }
 
 size_t ZSTD_ldm_generateSequences(
         ldmState_t* ldmState, rawSeqStore_t* sequences,
         ldmParams_t const* params, void const* src, size_t srcSize)
 {
     U32 const maxDist = 1U << params->windowLog;
     BYTE const* const istart = (BYTE const*)src;
     BYTE const* const iend = istart + srcSize;
     size_t const kMaxChunkSize = 1 << 20;
     size_t const nbChunks = (srcSize / kMaxChunkSize) + ((srcSize % kMaxChunkSize) != 0);
     size_t chunk;
     size_t leftoverSize = 0;
 
     assert(ZSTD_CHUNKSIZE_MAX >= kMaxChunkSize);
     /* Check that ZSTD_window_update() has been called for this chunk prior
      * to passing it to this function.
      */
     assert(ldmState->window.nextSrc >= (BYTE const*)src + srcSize);
     /* The input could be very large (in zstdmt), so it must be broken up into
      * chunks to enforce the maximum distance and handle overflow correction.
      */
     assert(sequences->pos <= sequences->size);
     assert(sequences->size <= sequences->capacity);
     for (chunk = 0; chunk < nbChunks && sequences->size < sequences->capacity; ++chunk) {
         BYTE const* const chunkStart = istart + chunk * kMaxChunkSize;
         size_t const remaining = (size_t)(iend - chunkStart);
         BYTE const *const chunkEnd =
             (remaining < kMaxChunkSize) ? iend : chunkStart + kMaxChunkSize;
         size_t const chunkSize = chunkEnd - chunkStart;
         size_t newLeftoverSize;
         size_t const prevSize = sequences->size;
 
         assert(chunkStart < iend);
         /* 1. Perform overflow correction if necessary. */
         if (ZSTD_window_needOverflowCorrection(ldmState->window, chunkEnd)) {
             U32 const ldmHSize = 1U << params->hashLog;
             U32 const correction = ZSTD_window_correctOverflow(
                 &ldmState->window, /* cycleLog */ 0, maxDist, chunkStart);
             ZSTD_ldm_reduceTable(ldmState->hashTable, ldmHSize, correction);
         }
         /* 2. We enforce the maximum offset allowed.
          *
          * kMaxChunkSize should be small enough that we don't lose too much of
          * the window through early invalidation.
          * TODO: * Test the chunk size.
          *       * Try invalidation after the sequence generation and test the
          *         the offset against maxDist directly.
          */
         ZSTD_window_enforceMaxDist(&ldmState->window, chunkEnd, maxDist, NULL, NULL);
         /* 3. Generate the sequences for the chunk, and get newLeftoverSize. */
         newLeftoverSize = ZSTD_ldm_generateSequences_internal(
             ldmState, sequences, params, chunkStart, chunkSize);
         if (ZSTD_isError(newLeftoverSize))
             return newLeftoverSize;
         /* 4. We add the leftover literals from previous iterations to the first
          *    newly generated sequence, or add the `newLeftoverSize` if none are
          *    generated.
          */
         /* Prepend the leftover literals from the last call */
         if (prevSize < sequences->size) {
             sequences->seq[prevSize].litLength += (U32)leftoverSize;
             leftoverSize = newLeftoverSize;
         } else {
             assert(newLeftoverSize == chunkSize);
             leftoverSize += chunkSize;
         }
     }
     return 0;
 }
 
 void ZSTD_ldm_skipSequences(rawSeqStore_t* rawSeqStore, size_t srcSize, U32 const minMatch) {
     while (srcSize > 0 && rawSeqStore->pos < rawSeqStore->size) {
         rawSeq* seq = rawSeqStore->seq + rawSeqStore->pos;
         if (srcSize <= seq->litLength) {
             /* Skip past srcSize literals */
             seq->litLength -= (U32)srcSize;
             return;
         }
         srcSize -= seq->litLength;
         seq->litLength = 0;
         if (srcSize < seq->matchLength) {
             /* Skip past the first srcSize of the match */
             seq->matchLength -= (U32)srcSize;
             if (seq->matchLength < minMatch) {
                 /* The match is too short, omit it */
                 if (rawSeqStore->pos + 1 < rawSeqStore->size) {
                     seq[1].litLength += seq[0].matchLength;
                 }
                 rawSeqStore->pos++;
             }
             return;
         }
         srcSize -= seq->matchLength;
         seq->matchLength = 0;
         rawSeqStore->pos++;
     }
 }
 
 /**
  * If the sequence length is longer than remaining then the sequence is split
  * between this block and the next.
  *
  * Returns the current sequence to handle, or if the rest of the block should
  * be literals, it returns a sequence with offset == 0.
  */
 static rawSeq maybeSplitSequence(rawSeqStore_t* rawSeqStore,
                                  U32 const remaining, U32 const minMatch)
 {
     rawSeq sequence = rawSeqStore->seq[rawSeqStore->pos];
     assert(sequence.offset > 0);
     /* Likely: No partial sequence */
     if (remaining >= sequence.litLength + sequence.matchLength) {
         rawSeqStore->pos++;
         return sequence;
     }
     /* Cut the sequence short (offset == 0 ==> rest is literals). */
     if (remaining <= sequence.litLength) {
         sequence.offset = 0;
     } else if (remaining < sequence.litLength + sequence.matchLength) {
         sequence.matchLength = remaining - sequence.litLength;
         if (sequence.matchLength < minMatch) {
             sequence.offset = 0;
         }
     }
     /* Skip past `remaining` bytes for the future sequences. */
     ZSTD_ldm_skipSequences(rawSeqStore, remaining, minMatch);
     return sequence;
 }
 
 size_t ZSTD_ldm_blockCompress(rawSeqStore_t* rawSeqStore,
     ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
     void const* src, size_t srcSize)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     unsigned const minMatch = cParams->minMatch;
     ZSTD_blockCompressor const blockCompressor =
         ZSTD_selectBlockCompressor(cParams->strategy, ZSTD_matchState_dictMode(ms));
     /* Input bounds */
     BYTE const* const istart = (BYTE const*)src;
     BYTE const* const iend = istart + srcSize;
     /* Input positions */
     BYTE const* ip = istart;
 
     DEBUGLOG(5, "ZSTD_ldm_blockCompress: srcSize=%zu", srcSize);
     assert(rawSeqStore->pos <= rawSeqStore->size);
     assert(rawSeqStore->size <= rawSeqStore->capacity);
     /* Loop through each sequence and apply the block compressor to the lits */
     while (rawSeqStore->pos < rawSeqStore->size && ip < iend) {
         /* maybeSplitSequence updates rawSeqStore->pos */
         rawSeq const sequence = maybeSplitSequence(rawSeqStore,
                                                    (U32)(iend - ip), minMatch);
         int i;
         /* End signal */
         if (sequence.offset == 0)
             break;
 
         assert(sequence.offset <= (1U << cParams->windowLog));
         assert(ip + sequence.litLength + sequence.matchLength <= iend);
 
         /* Fill tables for block compressor */
         ZSTD_ldm_limitTableUpdate(ms, ip);
         ZSTD_ldm_fillFastTables(ms, ip);
         /* Run the block compressor */
         DEBUGLOG(5, "calling block compressor on segment of size %u", sequence.litLength);
         {
             size_t const newLitLength =
                 blockCompressor(ms, seqStore, rep, ip, sequence.litLength);
             ip += sequence.litLength;
             /* Update the repcodes */
             for (i = ZSTD_REP_NUM - 1; i > 0; i--)
                 rep[i] = rep[i-1];
             rep[0] = sequence.offset;
             /* Store the sequence */
-            ZSTD_storeSeq(seqStore, newLitLength, ip - newLitLength,
+            ZSTD_storeSeq(seqStore, newLitLength, ip - newLitLength, iend,
                           sequence.offset + ZSTD_REP_MOVE,
                           sequence.matchLength - MINMATCH);
             ip += sequence.matchLength;
         }
     }
     /* Fill the tables for the block compressor */
     ZSTD_ldm_limitTableUpdate(ms, ip);
     ZSTD_ldm_fillFastTables(ms, ip);
     /* Compress the last literals */
     return blockCompressor(ms, seqStore, rep, ip, iend - ip);
 }
Index: head/sys/contrib/zstd/lib/compress/zstd_opt.c
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstd_opt.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstd_opt.c	(revision 354777)
@@ -1,1246 +1,1246 @@
 /*
  * Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 #include "zstd_compress_internal.h"
 #include "hist.h"
 #include "zstd_opt.h"
 
 
 #define ZSTD_LITFREQ_ADD    2   /* scaling factor for litFreq, so that frequencies adapt faster to new stats */
 #define ZSTD_FREQ_DIV       4   /* log factor when using previous stats to init next stats */
 #define ZSTD_MAX_PRICE     (1<<30)
 
 #define ZSTD_PREDEF_THRESHOLD 1024   /* if srcSize < ZSTD_PREDEF_THRESHOLD, symbols' cost is assumed static, directly determined by pre-defined distributions */
 
 
 /*-*************************************
 *  Price functions for optimal parser
 ***************************************/
 
 #if 0    /* approximation at bit level */
 #  define BITCOST_ACCURACY 0
 #  define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
 #  define WEIGHT(stat)  ((void)opt, ZSTD_bitWeight(stat))
 #elif 0  /* fractional bit accuracy */
 #  define BITCOST_ACCURACY 8
 #  define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
 #  define WEIGHT(stat,opt) ((void)opt, ZSTD_fracWeight(stat))
 #else    /* opt==approx, ultra==accurate */
 #  define BITCOST_ACCURACY 8
 #  define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
 #  define WEIGHT(stat,opt) (opt ? ZSTD_fracWeight(stat) : ZSTD_bitWeight(stat))
 #endif
 
 MEM_STATIC U32 ZSTD_bitWeight(U32 stat)
 {
     return (ZSTD_highbit32(stat+1) * BITCOST_MULTIPLIER);
 }
 
 MEM_STATIC U32 ZSTD_fracWeight(U32 rawStat)
 {
     U32 const stat = rawStat + 1;
     U32 const hb = ZSTD_highbit32(stat);
     U32 const BWeight = hb * BITCOST_MULTIPLIER;
     U32 const FWeight = (stat << BITCOST_ACCURACY) >> hb;
     U32 const weight = BWeight + FWeight;
     assert(hb + BITCOST_ACCURACY < 31);
     return weight;
 }
 
 #if (DEBUGLEVEL>=2)
 /* debugging function,
  * @return price in bytes as fractional value
  * for debug messages only */
 MEM_STATIC double ZSTD_fCost(U32 price)
 {
     return (double)price / (BITCOST_MULTIPLIER*8);
 }
 #endif
 
 static int ZSTD_compressedLiterals(optState_t const* const optPtr)
 {
     return optPtr->literalCompressionMode != ZSTD_lcm_uncompressed;
 }
 
 static void ZSTD_setBasePrices(optState_t* optPtr, int optLevel)
 {
     if (ZSTD_compressedLiterals(optPtr))
         optPtr->litSumBasePrice = WEIGHT(optPtr->litSum, optLevel);
     optPtr->litLengthSumBasePrice = WEIGHT(optPtr->litLengthSum, optLevel);
     optPtr->matchLengthSumBasePrice = WEIGHT(optPtr->matchLengthSum, optLevel);
     optPtr->offCodeSumBasePrice = WEIGHT(optPtr->offCodeSum, optLevel);
 }
 
 
 /* ZSTD_downscaleStat() :
  * reduce all elements in table by a factor 2^(ZSTD_FREQ_DIV+malus)
  * return the resulting sum of elements */
 static U32 ZSTD_downscaleStat(unsigned* table, U32 lastEltIndex, int malus)
 {
     U32 s, sum=0;
     DEBUGLOG(5, "ZSTD_downscaleStat (nbElts=%u)", (unsigned)lastEltIndex+1);
     assert(ZSTD_FREQ_DIV+malus > 0 && ZSTD_FREQ_DIV+malus < 31);
     for (s=0; s> (ZSTD_FREQ_DIV+malus));
         sum += table[s];
     }
     return sum;
 }
 
 /* ZSTD_rescaleFreqs() :
  * if first block (detected by optPtr->litLengthSum == 0) : init statistics
  *    take hints from dictionary if there is one
  *    or init from zero, using src for literals stats, or flat 1 for match symbols
  * otherwise downscale existing stats, to be used as seed for next block.
  */
 static void
 ZSTD_rescaleFreqs(optState_t* const optPtr,
             const BYTE* const src, size_t const srcSize,
                   int const optLevel)
 {
     int const compressedLiterals = ZSTD_compressedLiterals(optPtr);
     DEBUGLOG(5, "ZSTD_rescaleFreqs (srcSize=%u)", (unsigned)srcSize);
     optPtr->priceType = zop_dynamic;
 
     if (optPtr->litLengthSum == 0) {  /* first block : init */
         if (srcSize <= ZSTD_PREDEF_THRESHOLD) {  /* heuristic */
             DEBUGLOG(5, "(srcSize <= ZSTD_PREDEF_THRESHOLD) => zop_predef");
             optPtr->priceType = zop_predef;
         }
 
         assert(optPtr->symbolCosts != NULL);
         if (optPtr->symbolCosts->huf.repeatMode == HUF_repeat_valid) {
             /* huffman table presumed generated by dictionary */
             optPtr->priceType = zop_dynamic;
 
             if (compressedLiterals) {
                 unsigned lit;
                 assert(optPtr->litFreq != NULL);
                 optPtr->litSum = 0;
                 for (lit=0; lit<=MaxLit; lit++) {
                     U32 const scaleLog = 11;   /* scale to 2K */
                     U32 const bitCost = HUF_getNbBits(optPtr->symbolCosts->huf.CTable, lit);
                     assert(bitCost <= scaleLog);
                     optPtr->litFreq[lit] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
                     optPtr->litSum += optPtr->litFreq[lit];
             }   }
 
             {   unsigned ll;
                 FSE_CState_t llstate;
                 FSE_initCState(&llstate, optPtr->symbolCosts->fse.litlengthCTable);
                 optPtr->litLengthSum = 0;
                 for (ll=0; ll<=MaxLL; ll++) {
                     U32 const scaleLog = 10;   /* scale to 1K */
                     U32 const bitCost = FSE_getMaxNbBits(llstate.symbolTT, ll);
                     assert(bitCost < scaleLog);
                     optPtr->litLengthFreq[ll] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
                     optPtr->litLengthSum += optPtr->litLengthFreq[ll];
             }   }
 
             {   unsigned ml;
                 FSE_CState_t mlstate;
                 FSE_initCState(&mlstate, optPtr->symbolCosts->fse.matchlengthCTable);
                 optPtr->matchLengthSum = 0;
                 for (ml=0; ml<=MaxML; ml++) {
                     U32 const scaleLog = 10;
                     U32 const bitCost = FSE_getMaxNbBits(mlstate.symbolTT, ml);
                     assert(bitCost < scaleLog);
                     optPtr->matchLengthFreq[ml] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
                     optPtr->matchLengthSum += optPtr->matchLengthFreq[ml];
             }   }
 
             {   unsigned of;
                 FSE_CState_t ofstate;
                 FSE_initCState(&ofstate, optPtr->symbolCosts->fse.offcodeCTable);
                 optPtr->offCodeSum = 0;
                 for (of=0; of<=MaxOff; of++) {
                     U32 const scaleLog = 10;
                     U32 const bitCost = FSE_getMaxNbBits(ofstate.symbolTT, of);
                     assert(bitCost < scaleLog);
                     optPtr->offCodeFreq[of] = bitCost ? 1 << (scaleLog-bitCost) : 1 /*minimum to calculate cost*/;
                     optPtr->offCodeSum += optPtr->offCodeFreq[of];
             }   }
 
         } else {  /* not a dictionary */
 
             assert(optPtr->litFreq != NULL);
             if (compressedLiterals) {
                 unsigned lit = MaxLit;
                 HIST_count_simple(optPtr->litFreq, &lit, src, srcSize);   /* use raw first block to init statistics */
                 optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
             }
 
             {   unsigned ll;
                 for (ll=0; ll<=MaxLL; ll++)
                     optPtr->litLengthFreq[ll] = 1;
             }
             optPtr->litLengthSum = MaxLL+1;
 
             {   unsigned ml;
                 for (ml=0; ml<=MaxML; ml++)
                     optPtr->matchLengthFreq[ml] = 1;
             }
             optPtr->matchLengthSum = MaxML+1;
 
             {   unsigned of;
                 for (of=0; of<=MaxOff; of++)
                     optPtr->offCodeFreq[of] = 1;
             }
             optPtr->offCodeSum = MaxOff+1;
 
         }
 
     } else {   /* new block : re-use previous statistics, scaled down */
 
         if (compressedLiterals)
             optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
         optPtr->litLengthSum = ZSTD_downscaleStat(optPtr->litLengthFreq, MaxLL, 0);
         optPtr->matchLengthSum = ZSTD_downscaleStat(optPtr->matchLengthFreq, MaxML, 0);
         optPtr->offCodeSum = ZSTD_downscaleStat(optPtr->offCodeFreq, MaxOff, 0);
     }
 
     ZSTD_setBasePrices(optPtr, optLevel);
 }
 
 /* ZSTD_rawLiteralsCost() :
  * price of literals (only) in specified segment (which length can be 0).
  * does not include price of literalLength symbol */
 static U32 ZSTD_rawLiteralsCost(const BYTE* const literals, U32 const litLength,
                                 const optState_t* const optPtr,
                                 int optLevel)
 {
     if (litLength == 0) return 0;
 
     if (!ZSTD_compressedLiterals(optPtr))
         return (litLength << 3) * BITCOST_MULTIPLIER;  /* Uncompressed - 8 bytes per literal. */
 
     if (optPtr->priceType == zop_predef)
         return (litLength*6) * BITCOST_MULTIPLIER;  /* 6 bit per literal - no statistic used */
 
     /* dynamic statistics */
     {   U32 price = litLength * optPtr->litSumBasePrice;
         U32 u;
         for (u=0; u < litLength; u++) {
             assert(WEIGHT(optPtr->litFreq[literals[u]], optLevel) <= optPtr->litSumBasePrice);   /* literal cost should never be negative */
             price -= WEIGHT(optPtr->litFreq[literals[u]], optLevel);
         }
         return price;
     }
 }
 
 /* ZSTD_litLengthPrice() :
  * cost of literalLength symbol */
 static U32 ZSTD_litLengthPrice(U32 const litLength, const optState_t* const optPtr, int optLevel)
 {
     if (optPtr->priceType == zop_predef) return WEIGHT(litLength, optLevel);
 
     /* dynamic statistics */
     {   U32 const llCode = ZSTD_LLcode(litLength);
         return (LL_bits[llCode] * BITCOST_MULTIPLIER)
              + optPtr->litLengthSumBasePrice
              - WEIGHT(optPtr->litLengthFreq[llCode], optLevel);
     }
 }
 
 /* ZSTD_litLengthContribution() :
  * @return ( cost(litlength) - cost(0) )
  * this value can then be added to rawLiteralsCost()
  * to provide a cost which is directly comparable to a match ending at same position */
 static int ZSTD_litLengthContribution(U32 const litLength, const optState_t* const optPtr, int optLevel)
 {
     if (optPtr->priceType >= zop_predef) return (int)WEIGHT(litLength, optLevel);
 
     /* dynamic statistics */
     {   U32 const llCode = ZSTD_LLcode(litLength);
         int const contribution = (int)(LL_bits[llCode] * BITCOST_MULTIPLIER)
                                + (int)WEIGHT(optPtr->litLengthFreq[0], optLevel)   /* note: log2litLengthSum cancel out */
                                - (int)WEIGHT(optPtr->litLengthFreq[llCode], optLevel);
 #if 1
         return contribution;
 #else
         return MAX(0, contribution); /* sometimes better, sometimes not ... */
 #endif
     }
 }
 
 /* ZSTD_literalsContribution() :
  * creates a fake cost for the literals part of a sequence
  * which can be compared to the ending cost of a match
  * should a new match start at this position */
 static int ZSTD_literalsContribution(const BYTE* const literals, U32 const litLength,
                                      const optState_t* const optPtr,
                                      int optLevel)
 {
     int const contribution = (int)ZSTD_rawLiteralsCost(literals, litLength, optPtr, optLevel)
                            + ZSTD_litLengthContribution(litLength, optPtr, optLevel);
     return contribution;
 }
 
 /* ZSTD_getMatchPrice() :
  * Provides the cost of the match part (offset + matchLength) of a sequence
  * Must be combined with ZSTD_fullLiteralsCost() to get the full cost of a sequence.
  * optLevel: when <2, favors small offset for decompression speed (improved cache efficiency) */
 FORCE_INLINE_TEMPLATE U32
 ZSTD_getMatchPrice(U32 const offset,
                    U32 const matchLength,
              const optState_t* const optPtr,
                    int const optLevel)
 {
     U32 price;
     U32 const offCode = ZSTD_highbit32(offset+1);
     U32 const mlBase = matchLength - MINMATCH;
     assert(matchLength >= MINMATCH);
 
     if (optPtr->priceType == zop_predef)  /* fixed scheme, do not use statistics */
         return WEIGHT(mlBase, optLevel) + ((16 + offCode) * BITCOST_MULTIPLIER);
 
     /* dynamic statistics */
     price = (offCode * BITCOST_MULTIPLIER) + (optPtr->offCodeSumBasePrice - WEIGHT(optPtr->offCodeFreq[offCode], optLevel));
     if ((optLevel<2) /*static*/ && offCode >= 20)
         price += (offCode-19)*2 * BITCOST_MULTIPLIER; /* handicap for long distance offsets, favor decompression speed */
 
     /* match Length */
     {   U32 const mlCode = ZSTD_MLcode(mlBase);
         price += (ML_bits[mlCode] * BITCOST_MULTIPLIER) + (optPtr->matchLengthSumBasePrice - WEIGHT(optPtr->matchLengthFreq[mlCode], optLevel));
     }
 
     price += BITCOST_MULTIPLIER / 5;   /* heuristic : make matches a bit more costly to favor less sequences -> faster decompression speed */
 
     DEBUGLOG(8, "ZSTD_getMatchPrice(ml:%u) = %u", matchLength, price);
     return price;
 }
 
 /* ZSTD_updateStats() :
  * assumption : literals + litLengtn <= iend */
 static void ZSTD_updateStats(optState_t* const optPtr,
                              U32 litLength, const BYTE* literals,
                              U32 offsetCode, U32 matchLength)
 {
     /* literals */
     if (ZSTD_compressedLiterals(optPtr)) {
         U32 u;
         for (u=0; u < litLength; u++)
             optPtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
         optPtr->litSum += litLength*ZSTD_LITFREQ_ADD;
     }
 
     /* literal Length */
     {   U32 const llCode = ZSTD_LLcode(litLength);
         optPtr->litLengthFreq[llCode]++;
         optPtr->litLengthSum++;
     }
 
     /* match offset code (0-2=>repCode; 3+=>offset+2) */
     {   U32 const offCode = ZSTD_highbit32(offsetCode+1);
         assert(offCode <= MaxOff);
         optPtr->offCodeFreq[offCode]++;
         optPtr->offCodeSum++;
     }
 
     /* match Length */
     {   U32 const mlBase = matchLength - MINMATCH;
         U32 const mlCode = ZSTD_MLcode(mlBase);
         optPtr->matchLengthFreq[mlCode]++;
         optPtr->matchLengthSum++;
     }
 }
 
 
 /* ZSTD_readMINMATCH() :
  * function safe only for comparisons
  * assumption : memPtr must be at least 4 bytes before end of buffer */
 MEM_STATIC U32 ZSTD_readMINMATCH(const void* memPtr, U32 length)
 {
     switch (length)
     {
     default :
     case 4 : return MEM_read32(memPtr);
     case 3 : if (MEM_isLittleEndian())
                 return MEM_read32(memPtr)<<8;
              else
                 return MEM_read32(memPtr)>>8;
     }
 }
 
 
 /* Update hashTable3 up to ip (excluded)
    Assumption : always within prefix (i.e. not within extDict) */
 static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_matchState_t* ms,
                                               U32* nextToUpdate3,
                                               const BYTE* const ip)
 {
     U32* const hashTable3 = ms->hashTable3;
     U32 const hashLog3 = ms->hashLog3;
     const BYTE* const base = ms->window.base;
     U32 idx = *nextToUpdate3;
     U32 const target = (U32)(ip - base);
     size_t const hash3 = ZSTD_hash3Ptr(ip, hashLog3);
     assert(hashLog3 > 0);
 
     while(idx < target) {
         hashTable3[ZSTD_hash3Ptr(base+idx, hashLog3)] = idx;
         idx++;
     }
 
     *nextToUpdate3 = target;
     return hashTable3[hash3];
 }
 
 
 /*-*************************************
 *  Binary Tree search
 ***************************************/
 /** ZSTD_insertBt1() : add one or multiple positions to tree.
  *  ip : assumed <= iend-8 .
  * @return : nb of positions added */
 static U32 ZSTD_insertBt1(
                 ZSTD_matchState_t* ms,
                 const BYTE* const ip, const BYTE* const iend,
                 U32 const mls, const int extDict)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32*   const hashTable = ms->hashTable;
     U32    const hashLog = cParams->hashLog;
     size_t const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32*   const bt = ms->chainTable;
     U32    const btLog  = cParams->chainLog - 1;
     U32    const btMask = (1 << btLog) - 1;
     U32 matchIndex = hashTable[h];
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const base = ms->window.base;
     const BYTE* const dictBase = ms->window.dictBase;
     const U32 dictLimit = ms->window.dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     const BYTE* match;
     const U32 current = (U32)(ip-base);
     const U32 btLow = btMask >= current ? 0 : current - btMask;
     U32* smallerPtr = bt + 2*(current&btMask);
     U32* largerPtr  = smallerPtr + 1;
     U32 dummy32;   /* to be nullified at the end */
     U32 const windowLow = ms->window.lowLimit;
     U32 matchEndIdx = current+8+1;
     size_t bestLength = 8;
     U32 nbCompares = 1U << cParams->searchLog;
 #ifdef ZSTD_C_PREDICT
     U32 predictedSmall = *(bt + 2*((current-1)&btMask) + 0);
     U32 predictedLarge = *(bt + 2*((current-1)&btMask) + 1);
     predictedSmall += (predictedSmall>0);
     predictedLarge += (predictedLarge>0);
 #endif /* ZSTD_C_PREDICT */
 
     DEBUGLOG(8, "ZSTD_insertBt1 (%u)", current);
 
     assert(ip <= iend-8);   /* required for h calculation */
     hashTable[h] = current;   /* Update Hash Table */
 
     assert(windowLow > 0);
     while (nbCompares-- && (matchIndex >= windowLow)) {
         U32* const nextPtr = bt + 2*(matchIndex & btMask);
         size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
         assert(matchIndex < current);
 
 #ifdef ZSTD_C_PREDICT   /* note : can create issues when hlog small <= 11 */
         const U32* predictPtr = bt + 2*((matchIndex-1) & btMask);   /* written this way, as bt is a roll buffer */
         if (matchIndex == predictedSmall) {
             /* no need to check length, result known */
             *smallerPtr = matchIndex;
             if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
             smallerPtr = nextPtr+1;               /* new "smaller" => larger of match */
             matchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
             predictedSmall = predictPtr[1] + (predictPtr[1]>0);
             continue;
         }
         if (matchIndex == predictedLarge) {
             *largerPtr = matchIndex;
             if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
             largerPtr = nextPtr;
             matchIndex = nextPtr[0];
             predictedLarge = predictPtr[0] + (predictPtr[0]>0);
             continue;
         }
 #endif
 
         if (!extDict || (matchIndex+matchLength >= dictLimit)) {
             assert(matchIndex+matchLength >= dictLimit);   /* might be wrong if actually extDict */
             match = base + matchIndex;
             matchLength += ZSTD_count(ip+matchLength, match+matchLength, iend);
         } else {
             match = dictBase + matchIndex;
             matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iend, dictEnd, prefixStart);
             if (matchIndex+matchLength >= dictLimit)
                 match = base + matchIndex;   /* to prepare for next usage of match[matchLength] */
         }
 
         if (matchLength > bestLength) {
             bestLength = matchLength;
             if (matchLength > matchEndIdx - matchIndex)
                 matchEndIdx = matchIndex + (U32)matchLength;
         }
 
         if (ip+matchLength == iend) {   /* equal : no way to know if inf or sup */
             break;   /* drop , to guarantee consistency ; miss a bit of compression, but other solutions can corrupt tree */
         }
 
         if (match[matchLength] < ip[matchLength]) {  /* necessarily within buffer */
             /* match is smaller than current */
             *smallerPtr = matchIndex;             /* update smaller idx */
             commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
             if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop searching */
             smallerPtr = nextPtr+1;               /* new "candidate" => larger than match, which was smaller than target */
             matchIndex = nextPtr[1];              /* new matchIndex, larger than previous and closer to current */
         } else {
             /* match is larger than current */
             *largerPtr = matchIndex;
             commonLengthLarger = matchLength;
             if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop searching */
             largerPtr = nextPtr;
             matchIndex = nextPtr[0];
     }   }
 
     *smallerPtr = *largerPtr = 0;
     {   U32 positions = 0;
         if (bestLength > 384) positions = MIN(192, (U32)(bestLength - 384));   /* speed optimization */
         assert(matchEndIdx > current + 8);
         return MAX(positions, matchEndIdx - (current + 8));
     }
 }
 
 FORCE_INLINE_TEMPLATE
 void ZSTD_updateTree_internal(
                 ZSTD_matchState_t* ms,
                 const BYTE* const ip, const BYTE* const iend,
                 const U32 mls, const ZSTD_dictMode_e dictMode)
 {
     const BYTE* const base = ms->window.base;
     U32 const target = (U32)(ip - base);
     U32 idx = ms->nextToUpdate;
     DEBUGLOG(6, "ZSTD_updateTree_internal, from %u to %u  (dictMode:%u)",
                 idx, target, dictMode);
 
     while(idx < target) {
         U32 const forward = ZSTD_insertBt1(ms, base+idx, iend, mls, dictMode == ZSTD_extDict);
         assert(idx < (U32)(idx + forward));
         idx += forward;
     }
     assert((size_t)(ip - base) <= (size_t)(U32)(-1));
     assert((size_t)(iend - base) <= (size_t)(U32)(-1));
     ms->nextToUpdate = target;
 }
 
 void ZSTD_updateTree(ZSTD_matchState_t* ms, const BYTE* ip, const BYTE* iend) {
     ZSTD_updateTree_internal(ms, ip, iend, ms->cParams.minMatch, ZSTD_noDict);
 }
 
 FORCE_INLINE_TEMPLATE
 U32 ZSTD_insertBtAndGetAllMatches (
                     ZSTD_match_t* matches,   /* store result (found matches) in this table (presumed large enough) */
                     ZSTD_matchState_t* ms,
                     U32* nextToUpdate3,
                     const BYTE* const ip, const BYTE* const iLimit, const ZSTD_dictMode_e dictMode,
                     const U32 rep[ZSTD_REP_NUM],
                     U32 const ll0,   /* tells if associated literal length is 0 or not. This value must be 0 or 1 */
                     const U32 lengthToBeat,
                     U32 const mls /* template */)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
-    U32 const maxDistance = 1U << cParams->windowLog;
     const BYTE* const base = ms->window.base;
     U32 const current = (U32)(ip-base);
     U32 const hashLog = cParams->hashLog;
     U32 const minMatch = (mls==3) ? 3 : 4;
     U32* const hashTable = ms->hashTable;
     size_t const h  = ZSTD_hashPtr(ip, hashLog, mls);
     U32 matchIndex  = hashTable[h];
     U32* const bt   = ms->chainTable;
     U32 const btLog = cParams->chainLog - 1;
     U32 const btMask= (1U << btLog) - 1;
     size_t commonLengthSmaller=0, commonLengthLarger=0;
     const BYTE* const dictBase = ms->window.dictBase;
     U32 const dictLimit = ms->window.dictLimit;
     const BYTE* const dictEnd = dictBase + dictLimit;
     const BYTE* const prefixStart = base + dictLimit;
     U32 const btLow = (btMask >= current) ? 0 : current - btMask;
-    U32 const windowValid = ms->window.lowLimit;
-    U32 const windowLow = ((current - windowValid) > maxDistance) ? current - maxDistance : windowValid;
+    U32 const windowLow = ZSTD_getLowestMatchIndex(ms, current, cParams->windowLog);
     U32 const matchLow = windowLow ? windowLow : 1;
     U32* smallerPtr = bt + 2*(current&btMask);
     U32* largerPtr  = bt + 2*(current&btMask) + 1;
     U32 matchEndIdx = current+8+1;   /* farthest referenced position of any match => detects repetitive patterns */
     U32 dummy32;   /* to be nullified at the end */
     U32 mnum = 0;
     U32 nbCompares = 1U << cParams->searchLog;
 
     const ZSTD_matchState_t* dms    = dictMode == ZSTD_dictMatchState ? ms->dictMatchState : NULL;
     const ZSTD_compressionParameters* const dmsCParams =
                                       dictMode == ZSTD_dictMatchState ? &dms->cParams : NULL;
     const BYTE* const dmsBase       = dictMode == ZSTD_dictMatchState ? dms->window.base : NULL;
     const BYTE* const dmsEnd        = dictMode == ZSTD_dictMatchState ? dms->window.nextSrc : NULL;
     U32         const dmsHighLimit  = dictMode == ZSTD_dictMatchState ? (U32)(dmsEnd - dmsBase) : 0;
     U32         const dmsLowLimit   = dictMode == ZSTD_dictMatchState ? dms->window.lowLimit : 0;
     U32         const dmsIndexDelta = dictMode == ZSTD_dictMatchState ? windowLow - dmsHighLimit : 0;
     U32         const dmsHashLog    = dictMode == ZSTD_dictMatchState ? dmsCParams->hashLog : hashLog;
     U32         const dmsBtLog      = dictMode == ZSTD_dictMatchState ? dmsCParams->chainLog - 1 : btLog;
     U32         const dmsBtMask     = dictMode == ZSTD_dictMatchState ? (1U << dmsBtLog) - 1 : 0;
     U32         const dmsBtLow      = dictMode == ZSTD_dictMatchState && dmsBtMask < dmsHighLimit - dmsLowLimit ? dmsHighLimit - dmsBtMask : dmsLowLimit;
 
     size_t bestLength = lengthToBeat-1;
     DEBUGLOG(8, "ZSTD_insertBtAndGetAllMatches: current=%u", current);
 
     /* check repCode */
     assert(ll0 <= 1);   /* necessarily 1 or 0 */
     {   U32 const lastR = ZSTD_REP_NUM + ll0;
         U32 repCode;
         for (repCode = ll0; repCode < lastR; repCode++) {
             U32 const repOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
             U32 const repIndex = current - repOffset;
             U32 repLen = 0;
             assert(current >= dictLimit);
             if (repOffset-1 /* intentional overflow, discards 0 and -1 */ < current-dictLimit) {  /* equivalent to `current > repIndex >= dictLimit` */
                 if (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repOffset, minMatch)) {
                     repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iLimit) + minMatch;
                 }
             } else {  /* repIndex < dictLimit || repIndex >= current */
                 const BYTE* const repMatch = dictMode == ZSTD_dictMatchState ?
                                              dmsBase + repIndex - dmsIndexDelta :
                                              dictBase + repIndex;
                 assert(current >= windowLow);
                 if ( dictMode == ZSTD_extDict
                   && ( ((repOffset-1) /*intentional overflow*/ < current - windowLow)  /* equivalent to `current > repIndex >= windowLow` */
                      & (((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */)
                   && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
                     repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dictEnd, prefixStart) + minMatch;
                 }
                 if (dictMode == ZSTD_dictMatchState
                   && ( ((repOffset-1) /*intentional overflow*/ < current - (dmsLowLimit + dmsIndexDelta))  /* equivalent to `current > repIndex >= dmsLowLimit` */
                      & ((U32)((dictLimit-1) - repIndex) >= 3) ) /* intentional overflow : do not test positions overlapping 2 memory segments */
                   && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch)) ) {
                     repLen = (U32)ZSTD_count_2segments(ip+minMatch, repMatch+minMatch, iLimit, dmsEnd, prefixStart) + minMatch;
             }   }
             /* save longer solution */
             if (repLen > bestLength) {
                 DEBUGLOG(8, "found repCode %u (ll0:%u, offset:%u) of length %u",
                             repCode, ll0, repOffset, repLen);
                 bestLength = repLen;
                 matches[mnum].off = repCode - ll0;
                 matches[mnum].len = (U32)repLen;
                 mnum++;
                 if ( (repLen > sufficient_len)
                    | (ip+repLen == iLimit) ) {  /* best possible */
                     return mnum;
     }   }   }   }
 
     /* HC3 match finder */
     if ((mls == 3) /*static*/ && (bestLength < mls)) {
         U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(ms, nextToUpdate3, ip);
         if ((matchIndex3 >= matchLow)
           & (current - matchIndex3 < (1<<18)) /*heuristic : longer distance likely too expensive*/ ) {
             size_t mlen;
             if ((dictMode == ZSTD_noDict) /*static*/ || (dictMode == ZSTD_dictMatchState) /*static*/ || (matchIndex3 >= dictLimit)) {
                 const BYTE* const match = base + matchIndex3;
                 mlen = ZSTD_count(ip, match, iLimit);
             } else {
                 const BYTE* const match = dictBase + matchIndex3;
                 mlen = ZSTD_count_2segments(ip, match, iLimit, dictEnd, prefixStart);
             }
 
             /* save best solution */
             if (mlen >= mls /* == 3 > bestLength */) {
                 DEBUGLOG(8, "found small match with hlog3, of length %u",
                             (U32)mlen);
                 bestLength = mlen;
                 assert(current > matchIndex3);
                 assert(mnum==0);  /* no prior solution */
                 matches[0].off = (current - matchIndex3) + ZSTD_REP_MOVE;
                 matches[0].len = (U32)mlen;
                 mnum = 1;
                 if ( (mlen > sufficient_len) |
                      (ip+mlen == iLimit) ) {  /* best possible length */
                     ms->nextToUpdate = current+1;  /* skip insertion */
                     return 1;
         }   }   }
         /* no dictMatchState lookup: dicts don't have a populated HC3 table */
     }
 
     hashTable[h] = current;   /* Update Hash Table */
 
     while (nbCompares-- && (matchIndex >= matchLow)) {
         U32* const nextPtr = bt + 2*(matchIndex & btMask);
-        size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
         const BYTE* match;
+        size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
         assert(current > matchIndex);
 
         if ((dictMode == ZSTD_noDict) || (dictMode == ZSTD_dictMatchState) || (matchIndex+matchLength >= dictLimit)) {
             assert(matchIndex+matchLength >= dictLimit);  /* ensure the condition is correct when !extDict */
             match = base + matchIndex;
+            if (matchIndex >= dictLimit) assert(memcmp(match, ip, matchLength) == 0);  /* ensure early section of match is equal as expected */
             matchLength += ZSTD_count(ip+matchLength, match+matchLength, iLimit);
         } else {
             match = dictBase + matchIndex;
+            assert(memcmp(match, ip, matchLength) == 0);  /* ensure early section of match is equal as expected */
             matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dictEnd, prefixStart);
             if (matchIndex+matchLength >= dictLimit)
-                match = base + matchIndex;   /* prepare for match[matchLength] */
+                match = base + matchIndex;   /* prepare for match[matchLength] read */
         }
 
         if (matchLength > bestLength) {
             DEBUGLOG(8, "found match of length %u at distance %u (offCode=%u)",
                     (U32)matchLength, current - matchIndex, current - matchIndex + ZSTD_REP_MOVE);
             assert(matchEndIdx > matchIndex);
             if (matchLength > matchEndIdx - matchIndex)
                 matchEndIdx = matchIndex + (U32)matchLength;
             bestLength = matchLength;
             matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE;
             matches[mnum].len = (U32)matchLength;
             mnum++;
             if ( (matchLength > ZSTD_OPT_NUM)
                | (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) {
                 if (dictMode == ZSTD_dictMatchState) nbCompares = 0; /* break should also skip searching dms */
                 break; /* drop, to preserve bt consistency (miss a little bit of compression) */
             }
         }
 
         if (match[matchLength] < ip[matchLength]) {
             /* match smaller than current */
             *smallerPtr = matchIndex;             /* update smaller idx */
             commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
             if (matchIndex <= btLow) { smallerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
             smallerPtr = nextPtr+1;               /* new candidate => larger than match, which was smaller than current */
             matchIndex = nextPtr[1];              /* new matchIndex, larger than previous, closer to current */
         } else {
             *largerPtr = matchIndex;
             commonLengthLarger = matchLength;
             if (matchIndex <= btLow) { largerPtr=&dummy32; break; }   /* beyond tree size, stop the search */
             largerPtr = nextPtr;
             matchIndex = nextPtr[0];
     }   }
 
     *smallerPtr = *largerPtr = 0;
 
     if (dictMode == ZSTD_dictMatchState && nbCompares) {
         size_t const dmsH = ZSTD_hashPtr(ip, dmsHashLog, mls);
         U32 dictMatchIndex = dms->hashTable[dmsH];
         const U32* const dmsBt = dms->chainTable;
         commonLengthSmaller = commonLengthLarger = 0;
         while (nbCompares-- && (dictMatchIndex > dmsLowLimit)) {
             const U32* const nextPtr = dmsBt + 2*(dictMatchIndex & dmsBtMask);
             size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger);   /* guaranteed minimum nb of common bytes */
             const BYTE* match = dmsBase + dictMatchIndex;
             matchLength += ZSTD_count_2segments(ip+matchLength, match+matchLength, iLimit, dmsEnd, prefixStart);
             if (dictMatchIndex+matchLength >= dmsHighLimit)
                 match = base + dictMatchIndex + dmsIndexDelta;   /* to prepare for next usage of match[matchLength] */
 
             if (matchLength > bestLength) {
                 matchIndex = dictMatchIndex + dmsIndexDelta;
                 DEBUGLOG(8, "found dms match of length %u at distance %u (offCode=%u)",
                         (U32)matchLength, current - matchIndex, current - matchIndex + ZSTD_REP_MOVE);
                 if (matchLength > matchEndIdx - matchIndex)
                     matchEndIdx = matchIndex + (U32)matchLength;
                 bestLength = matchLength;
                 matches[mnum].off = (current - matchIndex) + ZSTD_REP_MOVE;
                 matches[mnum].len = (U32)matchLength;
                 mnum++;
                 if ( (matchLength > ZSTD_OPT_NUM)
                    | (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */) {
                     break;   /* drop, to guarantee consistency (miss a little bit of compression) */
                 }
             }
 
             if (dictMatchIndex <= dmsBtLow) { break; }   /* beyond tree size, stop the search */
             if (match[matchLength] < ip[matchLength]) {
                 commonLengthSmaller = matchLength;    /* all smaller will now have at least this guaranteed common length */
                 dictMatchIndex = nextPtr[1];              /* new matchIndex larger than previous (closer to current) */
             } else {
                 /* match is larger than current */
                 commonLengthLarger = matchLength;
                 dictMatchIndex = nextPtr[0];
             }
         }
     }
 
     assert(matchEndIdx > current+8);
     ms->nextToUpdate = matchEndIdx - 8;  /* skip repetitive patterns */
     return mnum;
 }
 
 
 FORCE_INLINE_TEMPLATE U32 ZSTD_BtGetAllMatches (
                         ZSTD_match_t* matches,   /* store result (match found, increasing size) in this table */
                         ZSTD_matchState_t* ms,
                         U32* nextToUpdate3,
                         const BYTE* ip, const BYTE* const iHighLimit, const ZSTD_dictMode_e dictMode,
                         const U32 rep[ZSTD_REP_NUM],
                         U32 const ll0,
                         U32 const lengthToBeat)
 {
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
     U32 const matchLengthSearch = cParams->minMatch;
     DEBUGLOG(8, "ZSTD_BtGetAllMatches");
     if (ip < ms->window.base + ms->nextToUpdate) return 0;   /* skipped area */
     ZSTD_updateTree_internal(ms, ip, iHighLimit, matchLengthSearch, dictMode);
     switch(matchLengthSearch)
     {
     case 3 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 3);
     default :
     case 4 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 4);
     case 5 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 5);
     case 7 :
     case 6 : return ZSTD_insertBtAndGetAllMatches(matches, ms, nextToUpdate3, ip, iHighLimit, dictMode, rep, ll0, lengthToBeat, 6);
     }
 }
 
 
 /*-*******************************
 *  Optimal parser
 *********************************/
 typedef struct repcodes_s {
     U32 rep[3];
 } repcodes_t;
 
 static repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0)
 {
     repcodes_t newReps;
     if (offset >= ZSTD_REP_NUM) {  /* full offset */
         newReps.rep[2] = rep[1];
         newReps.rep[1] = rep[0];
         newReps.rep[0] = offset - ZSTD_REP_MOVE;
     } else {   /* repcode */
         U32 const repCode = offset + ll0;
         if (repCode > 0) {  /* note : if repCode==0, no change */
             U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
             newReps.rep[2] = (repCode >= 2) ? rep[1] : rep[2];
             newReps.rep[1] = rep[0];
             newReps.rep[0] = currentOffset;
         } else {   /* repCode == 0 */
             memcpy(&newReps, rep, sizeof(newReps));
         }
     }
     return newReps;
 }
 
 
 static U32 ZSTD_totalLen(ZSTD_optimal_t sol)
 {
     return sol.litlen + sol.mlen;
 }
 
 #if 0 /* debug */
 
 static void
 listStats(const U32* table, int lastEltID)
 {
     int const nbElts = lastEltID + 1;
     int enb;
     for (enb=0; enb < nbElts; enb++) {
         (void)table;
         //RAWLOG(2, "%3i:%3i,  ", enb, table[enb]);
         RAWLOG(2, "%4i,", table[enb]);
     }
     RAWLOG(2, " \n");
 }
 
 #endif
 
 FORCE_INLINE_TEMPLATE size_t
 ZSTD_compressBlock_opt_generic(ZSTD_matchState_t* ms,
                                seqStore_t* seqStore,
                                U32 rep[ZSTD_REP_NUM],
                          const void* src, size_t srcSize,
                          const int optLevel,
                          const ZSTD_dictMode_e dictMode)
 {
     optState_t* const optStatePtr = &ms->opt;
     const BYTE* const istart = (const BYTE*)src;
     const BYTE* ip = istart;
     const BYTE* anchor = istart;
     const BYTE* const iend = istart + srcSize;
     const BYTE* const ilimit = iend - 8;
     const BYTE* const base = ms->window.base;
     const BYTE* const prefixStart = base + ms->window.dictLimit;
     const ZSTD_compressionParameters* const cParams = &ms->cParams;
 
     U32 const sufficient_len = MIN(cParams->targetLength, ZSTD_OPT_NUM -1);
     U32 const minMatch = (cParams->minMatch == 3) ? 3 : 4;
     U32 nextToUpdate3 = ms->nextToUpdate;
 
     ZSTD_optimal_t* const opt = optStatePtr->priceTable;
     ZSTD_match_t* const matches = optStatePtr->matchTable;
     ZSTD_optimal_t lastSequence;
 
     /* init */
     DEBUGLOG(5, "ZSTD_compressBlock_opt_generic: current=%u, prefix=%u, nextToUpdate=%u",
                 (U32)(ip - base), ms->window.dictLimit, ms->nextToUpdate);
     assert(optLevel <= 2);
     ZSTD_rescaleFreqs(optStatePtr, (const BYTE*)src, srcSize, optLevel);
     ip += (ip==prefixStart);
 
     /* Match Loop */
     while (ip < ilimit) {
         U32 cur, last_pos = 0;
 
         /* find first match */
         {   U32 const litlen = (U32)(ip - anchor);
             U32 const ll0 = !litlen;
             U32 const nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, ip, iend, dictMode, rep, ll0, minMatch);
             if (!nbMatches) { ip++; continue; }
 
             /* initialize opt[0] */
             { U32 i ; for (i=0; i immediate encoding */
             {   U32 const maxML = matches[nbMatches-1].len;
                 U32 const maxOffset = matches[nbMatches-1].off;
                 DEBUGLOG(6, "found %u matches of maxLength=%u and maxOffCode=%u at cPos=%u => start new series",
                             nbMatches, maxML, maxOffset, (U32)(ip-prefixStart));
 
                 if (maxML > sufficient_len) {
                     lastSequence.litlen = litlen;
                     lastSequence.mlen = maxML;
                     lastSequence.off = maxOffset;
                     DEBUGLOG(6, "large match (%u>%u), immediate encoding",
                                 maxML, sufficient_len);
                     cur = 0;
                     last_pos = ZSTD_totalLen(lastSequence);
                     goto _shortestPath;
             }   }
 
             /* set prices for first matches starting position == 0 */
             {   U32 const literalsPrice = opt[0].price + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
                 U32 pos;
                 U32 matchNb;
                 for (pos = 1; pos < minMatch; pos++) {
                     opt[pos].price = ZSTD_MAX_PRICE;   /* mlen, litlen and price will be fixed during forward scanning */
                 }
                 for (matchNb = 0; matchNb < nbMatches; matchNb++) {
                     U32 const offset = matches[matchNb].off;
                     U32 const end = matches[matchNb].len;
                     repcodes_t const repHistory = ZSTD_updateRep(rep, offset, ll0);
                     for ( ; pos <= end ; pos++ ) {
                         U32 const matchPrice = ZSTD_getMatchPrice(offset, pos, optStatePtr, optLevel);
                         U32 const sequencePrice = literalsPrice + matchPrice;
                         DEBUGLOG(7, "rPos:%u => set initial price : %.2f",
                                     pos, ZSTD_fCost(sequencePrice));
                         opt[pos].mlen = pos;
                         opt[pos].off = offset;
                         opt[pos].litlen = litlen;
                         opt[pos].price = sequencePrice;
                         ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory));
                         memcpy(opt[pos].rep, &repHistory, sizeof(repHistory));
                 }   }
                 last_pos = pos-1;
             }
         }
 
         /* check further positions */
         for (cur = 1; cur <= last_pos; cur++) {
             const BYTE* const inr = ip + cur;
             assert(cur < ZSTD_OPT_NUM);
             DEBUGLOG(7, "cPos:%zi==rPos:%u", inr-istart, cur)
 
             /* Fix current position with one literal if cheaper */
             {   U32 const litlen = (opt[cur-1].mlen == 0) ? opt[cur-1].litlen + 1 : 1;
                 int const price = opt[cur-1].price
                                 + ZSTD_rawLiteralsCost(ip+cur-1, 1, optStatePtr, optLevel)
                                 + ZSTD_litLengthPrice(litlen, optStatePtr, optLevel)
                                 - ZSTD_litLengthPrice(litlen-1, optStatePtr, optLevel);
                 assert(price < 1000000000); /* overflow check */
                 if (price <= opt[cur].price) {
                     DEBUGLOG(7, "cPos:%zi==rPos:%u : better price (%.2f<=%.2f) using literal (ll==%u) (hist:%u,%u,%u)",
                                 inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price), litlen,
                                 opt[cur-1].rep[0], opt[cur-1].rep[1], opt[cur-1].rep[2]);
                     opt[cur].mlen = 0;
                     opt[cur].off = 0;
                     opt[cur].litlen = litlen;
                     opt[cur].price = price;
                     memcpy(opt[cur].rep, opt[cur-1].rep, sizeof(opt[cur].rep));
                 } else {
                     DEBUGLOG(7, "cPos:%zi==rPos:%u : literal would cost more (%.2f>%.2f) (hist:%u,%u,%u)",
                                 inr-istart, cur, ZSTD_fCost(price), ZSTD_fCost(opt[cur].price),
                                 opt[cur].rep[0], opt[cur].rep[1], opt[cur].rep[2]);
                 }
             }
 
             /* last match must start at a minimum distance of 8 from oend */
             if (inr > ilimit) continue;
 
             if (cur == last_pos) break;
 
             if ( (optLevel==0) /*static_test*/
               && (opt[cur+1].price <= opt[cur].price + (BITCOST_MULTIPLIER/2)) ) {
                 DEBUGLOG(7, "move to next rPos:%u : price is <=", cur+1);
                 continue;  /* skip unpromising positions; about ~+6% speed, -0.01 ratio */
             }
 
             {   U32 const ll0 = (opt[cur].mlen != 0);
                 U32 const litlen = (opt[cur].mlen == 0) ? opt[cur].litlen : 0;
                 U32 const previousPrice = opt[cur].price;
                 U32 const basePrice = previousPrice + ZSTD_litLengthPrice(0, optStatePtr, optLevel);
                 U32 const nbMatches = ZSTD_BtGetAllMatches(matches, ms, &nextToUpdate3, inr, iend, dictMode, opt[cur].rep, ll0, minMatch);
                 U32 matchNb;
                 if (!nbMatches) {
                     DEBUGLOG(7, "rPos:%u : no match found", cur);
                     continue;
                 }
 
                 {   U32 const maxML = matches[nbMatches-1].len;
                     DEBUGLOG(7, "cPos:%zi==rPos:%u, found %u matches, of maxLength=%u",
                                 inr-istart, cur, nbMatches, maxML);
 
                     if ( (maxML > sufficient_len)
                       || (cur + maxML >= ZSTD_OPT_NUM) ) {
                         lastSequence.mlen = maxML;
                         lastSequence.off = matches[nbMatches-1].off;
                         lastSequence.litlen = litlen;
                         cur -= (opt[cur].mlen==0) ? opt[cur].litlen : 0;  /* last sequence is actually only literals, fix cur to last match - note : may underflow, in which case, it's first sequence, and it's okay */
                         last_pos = cur + ZSTD_totalLen(lastSequence);
                         if (cur > ZSTD_OPT_NUM) cur = 0;   /* underflow => first match */
                         goto _shortestPath;
                 }   }
 
                 /* set prices using matches found at position == cur */
                 for (matchNb = 0; matchNb < nbMatches; matchNb++) {
                     U32 const offset = matches[matchNb].off;
                     repcodes_t const repHistory = ZSTD_updateRep(opt[cur].rep, offset, ll0);
                     U32 const lastML = matches[matchNb].len;
                     U32 const startML = (matchNb>0) ? matches[matchNb-1].len+1 : minMatch;
                     U32 mlen;
 
                     DEBUGLOG(7, "testing match %u => offCode=%4u, mlen=%2u, llen=%2u",
                                 matchNb, matches[matchNb].off, lastML, litlen);
 
                     for (mlen = lastML; mlen >= startML; mlen--) {  /* scan downward */
                         U32 const pos = cur + mlen;
                         int const price = basePrice + ZSTD_getMatchPrice(offset, mlen, optStatePtr, optLevel);
 
                         if ((pos > last_pos) || (price < opt[pos].price)) {
                             DEBUGLOG(7, "rPos:%u (ml=%2u) => new better price (%.2f<%.2f)",
                                         pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price));
                             while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; }   /* fill empty positions */
                             opt[pos].mlen = mlen;
                             opt[pos].off = offset;
                             opt[pos].litlen = litlen;
                             opt[pos].price = price;
                             ZSTD_STATIC_ASSERT(sizeof(opt[pos].rep) == sizeof(repHistory));
                             memcpy(opt[pos].rep, &repHistory, sizeof(repHistory));
                         } else {
                             DEBUGLOG(7, "rPos:%u (ml=%2u) => new price is worse (%.2f>=%.2f)",
                                         pos, mlen, ZSTD_fCost(price), ZSTD_fCost(opt[pos].price));
                             if (optLevel==0) break;  /* early update abort; gets ~+10% speed for about -0.01 ratio loss */
                         }
             }   }   }
         }  /* for (cur = 1; cur <= last_pos; cur++) */
 
         lastSequence = opt[last_pos];
         cur = last_pos > ZSTD_totalLen(lastSequence) ? last_pos - ZSTD_totalLen(lastSequence) : 0;  /* single sequence, and it starts before `ip` */
         assert(cur < ZSTD_OPT_NUM);  /* control overflow*/
 
 _shortestPath:   /* cur, last_pos, best_mlen, best_off have to be set */
         assert(opt[0].mlen == 0);
 
         {   U32 const storeEnd = cur + 1;
             U32 storeStart = storeEnd;
             U32 seqPos = cur;
 
             DEBUGLOG(6, "start reverse traversal (last_pos:%u, cur:%u)",
                         last_pos, cur); (void)last_pos;
             assert(storeEnd < ZSTD_OPT_NUM);
             DEBUGLOG(6, "last sequence copied into pos=%u (llen=%u,mlen=%u,ofc=%u)",
                         storeEnd, lastSequence.litlen, lastSequence.mlen, lastSequence.off);
             opt[storeEnd] = lastSequence;
             while (seqPos > 0) {
                 U32 const backDist = ZSTD_totalLen(opt[seqPos]);
                 storeStart--;
                 DEBUGLOG(6, "sequence from rPos=%u copied into pos=%u (llen=%u,mlen=%u,ofc=%u)",
                             seqPos, storeStart, opt[seqPos].litlen, opt[seqPos].mlen, opt[seqPos].off);
                 opt[storeStart] = opt[seqPos];
                 seqPos = (seqPos > backDist) ? seqPos - backDist : 0;
             }
 
             /* save sequences */
             DEBUGLOG(6, "sending selected sequences into seqStore")
             {   U32 storePos;
                 for (storePos=storeStart; storePos <= storeEnd; storePos++) {
                     U32 const llen = opt[storePos].litlen;
                     U32 const mlen = opt[storePos].mlen;
                     U32 const offCode = opt[storePos].off;
                     U32 const advance = llen + mlen;
                     DEBUGLOG(6, "considering seq starting at %zi, llen=%u, mlen=%u",
                                 anchor - istart, (unsigned)llen, (unsigned)mlen);
 
                     if (mlen==0) {  /* only literals => must be last "sequence", actually starting a new stream of sequences */
                         assert(storePos == storeEnd);   /* must be last sequence */
                         ip = anchor + llen;     /* last "sequence" is a bunch of literals => don't progress anchor */
                         continue;   /* will finish */
                     }
 
                     /* repcodes update : like ZSTD_updateRep(), but update in place */
                     if (offCode >= ZSTD_REP_NUM) {  /* full offset */
                         rep[2] = rep[1];
                         rep[1] = rep[0];
                         rep[0] = offCode - ZSTD_REP_MOVE;
                     } else {   /* repcode */
                         U32 const repCode = offCode + (llen==0);
                         if (repCode) {  /* note : if repCode==0, no change */
                             U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
                             if (repCode >= 2) rep[2] = rep[1];
                             rep[1] = rep[0];
                             rep[0] = currentOffset;
                     }   }
 
                     assert(anchor + llen <= iend);
                     ZSTD_updateStats(optStatePtr, llen, anchor, offCode, mlen);
-                    ZSTD_storeSeq(seqStore, llen, anchor, offCode, mlen-MINMATCH);
+                    ZSTD_storeSeq(seqStore, llen, anchor, iend, offCode, mlen-MINMATCH);
                     anchor += advance;
                     ip = anchor;
             }   }
             ZSTD_setBasePrices(optStatePtr, optLevel);
         }
 
     }   /* while (ip < ilimit) */
 
     /* Return the last literals size */
     return (size_t)(iend - anchor);
 }
 
 
 size_t ZSTD_compressBlock_btopt(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         const void* src, size_t srcSize)
 {
     DEBUGLOG(5, "ZSTD_compressBlock_btopt");
     return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_noDict);
 }
 
 
 /* used in 2-pass strategy */
 static U32 ZSTD_upscaleStat(unsigned* table, U32 lastEltIndex, int bonus)
 {
     U32 s, sum=0;
     assert(ZSTD_FREQ_DIV+bonus >= 0);
     for (s=0; slitSum = ZSTD_upscaleStat(optPtr->litFreq, MaxLit, 0);
     optPtr->litLengthSum = ZSTD_upscaleStat(optPtr->litLengthFreq, MaxLL, 0);
     optPtr->matchLengthSum = ZSTD_upscaleStat(optPtr->matchLengthFreq, MaxML, 0);
     optPtr->offCodeSum = ZSTD_upscaleStat(optPtr->offCodeFreq, MaxOff, 0);
 }
 
 /* ZSTD_initStats_ultra():
  * make a first compression pass, just to seed stats with more accurate starting values.
  * only works on first block, with no dictionary and no ldm.
  * this function cannot error, hence its contract must be respected.
  */
 static void
 ZSTD_initStats_ultra(ZSTD_matchState_t* ms,
                      seqStore_t* seqStore,
                      U32 rep[ZSTD_REP_NUM],
                const void* src, size_t srcSize)
 {
     U32 tmpRep[ZSTD_REP_NUM];  /* updated rep codes will sink here */
     memcpy(tmpRep, rep, sizeof(tmpRep));
 
     DEBUGLOG(4, "ZSTD_initStats_ultra (srcSize=%zu)", srcSize);
     assert(ms->opt.litLengthSum == 0);    /* first block */
     assert(seqStore->sequences == seqStore->sequencesStart);   /* no ldm */
     assert(ms->window.dictLimit == ms->window.lowLimit);   /* no dictionary */
     assert(ms->window.dictLimit - ms->nextToUpdate <= 1);  /* no prefix (note: intentional overflow, defined as 2-complement) */
 
     ZSTD_compressBlock_opt_generic(ms, seqStore, tmpRep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);   /* generate stats into ms->opt*/
 
     /* invalidate first scan from history */
     ZSTD_resetSeqStore(seqStore);
     ms->window.base -= srcSize;
     ms->window.dictLimit += (U32)srcSize;
     ms->window.lowLimit = ms->window.dictLimit;
     ms->nextToUpdate = ms->window.dictLimit;
 
     /* re-inforce weight of collected statistics */
     ZSTD_upscaleStats(&ms->opt);
 }
 
 size_t ZSTD_compressBlock_btultra(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         const void* src, size_t srcSize)
 {
     DEBUGLOG(5, "ZSTD_compressBlock_btultra (srcSize=%zu)", srcSize);
     return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_btultra2(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         const void* src, size_t srcSize)
 {
     U32 const current = (U32)((const BYTE*)src - ms->window.base);
     DEBUGLOG(5, "ZSTD_compressBlock_btultra2 (srcSize=%zu)", srcSize);
 
     /* 2-pass strategy:
      * this strategy makes a first pass over first block to collect statistics
      * and seed next round's statistics with it.
      * After 1st pass, function forgets everything, and starts a new block.
      * Consequently, this can only work if no data has been previously loaded in tables,
      * aka, no dictionary, no prefix, no ldm preprocessing.
      * The compression ratio gain is generally small (~0.5% on first block),
      * the cost is 2x cpu time on first block. */
     assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
     if ( (ms->opt.litLengthSum==0)   /* first block */
       && (seqStore->sequences == seqStore->sequencesStart)  /* no ldm */
       && (ms->window.dictLimit == ms->window.lowLimit)   /* no dictionary */
       && (current == ms->window.dictLimit)   /* start of frame, nothing already loaded nor skipped */
       && (srcSize > ZSTD_PREDEF_THRESHOLD)
       ) {
         ZSTD_initStats_ultra(ms, seqStore, rep, src, srcSize);
     }
 
     return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_noDict);
 }
 
 size_t ZSTD_compressBlock_btopt_dictMatchState(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         const void* src, size_t srcSize)
 {
     return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_dictMatchState);
 }
 
 size_t ZSTD_compressBlock_btultra_dictMatchState(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         const void* src, size_t srcSize)
 {
     return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_dictMatchState);
 }
 
 size_t ZSTD_compressBlock_btopt_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         const void* src, size_t srcSize)
 {
     return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 0 /*optLevel*/, ZSTD_extDict);
 }
 
 size_t ZSTD_compressBlock_btultra_extDict(
         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
         const void* src, size_t srcSize)
 {
     return ZSTD_compressBlock_opt_generic(ms, seqStore, rep, src, srcSize, 2 /*optLevel*/, ZSTD_extDict);
 }
 
 /* note : no btultra2 variant for extDict nor dictMatchState,
  * because btultra2 is not meant to work with dictionaries
  * and is only specific for the first block (no prefix) */
Index: head/sys/contrib/zstd/lib/compress/zstdmt_compress.c
===================================================================
--- head/sys/contrib/zstd/lib/compress/zstdmt_compress.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/compress/zstdmt_compress.c	(revision 354777)
@@ -1,2110 +1,2116 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /* ======   Compiler specifics   ====== */
 #if defined(_MSC_VER)
 #  pragma warning(disable : 4204)   /* disable: C4204: non-constant aggregate initializer */
 #endif
 
 
 /* ======   Constants   ====== */
 #define ZSTDMT_OVERLAPLOG_DEFAULT 0
 
 
 /* ======   Dependencies   ====== */
 #include       /* memcpy, memset */
 #include       /* INT_MAX, UINT_MAX */
 #include "mem.h"         /* MEM_STATIC */
 #include "pool.h"        /* threadpool */
 #include "threading.h"   /* mutex */
 #include "zstd_compress_internal.h"  /* MIN, ERROR, ZSTD_*, ZSTD_highbit32 */
 #include "zstd_ldm.h"
 #include "zstdmt_compress.h"
 
 /* Guards code to support resizing the SeqPool.
  * We will want to resize the SeqPool to save memory in the future.
  * Until then, comment the code out since it is unused.
  */
 #define ZSTD_RESIZE_SEQPOOL 0
 
 /* ======   Debug   ====== */
 #if defined(DEBUGLEVEL) && (DEBUGLEVEL>=2) \
     && !defined(_MSC_VER) \
     && !defined(__MINGW32__)
 
 #  include 
 #  include 
 #  include 
 
 #  define DEBUG_PRINTHEX(l,p,n) {            \
     unsigned debug_u;                        \
     for (debug_u=0; debug_u<(n); debug_u++)  \
         RAWLOG(l, "%02X ", ((const unsigned char*)(p))[debug_u]); \
     RAWLOG(l, " \n");                        \
 }
 
 static unsigned long long GetCurrentClockTimeMicroseconds(void)
 {
    static clock_t _ticksPerSecond = 0;
    if (_ticksPerSecond <= 0) _ticksPerSecond = sysconf(_SC_CLK_TCK);
 
    {   struct tms junk; clock_t newTicks = (clock_t) times(&junk);
        return ((((unsigned long long)newTicks)*(1000000))/_ticksPerSecond);
 }  }
 
 #define MUTEX_WAIT_TIME_DLEVEL 6
 #define ZSTD_PTHREAD_MUTEX_LOCK(mutex) {          \
     if (DEBUGLEVEL >= MUTEX_WAIT_TIME_DLEVEL) {   \
         unsigned long long const beforeTime = GetCurrentClockTimeMicroseconds(); \
         ZSTD_pthread_mutex_lock(mutex);           \
         {   unsigned long long const afterTime = GetCurrentClockTimeMicroseconds(); \
             unsigned long long const elapsedTime = (afterTime-beforeTime); \
             if (elapsedTime > 1000) {  /* or whatever threshold you like; I'm using 1 millisecond here */ \
                 DEBUGLOG(MUTEX_WAIT_TIME_DLEVEL, "Thread took %llu microseconds to acquire mutex %s \n", \
                    elapsedTime, #mutex);          \
         }   }                                     \
     } else {                                      \
         ZSTD_pthread_mutex_lock(mutex);           \
     }                                             \
 }
 
 #else
 
 #  define ZSTD_PTHREAD_MUTEX_LOCK(m) ZSTD_pthread_mutex_lock(m)
 #  define DEBUG_PRINTHEX(l,p,n) {}
 
 #endif
 
 
 /* =====   Buffer Pool   ===== */
 /* a single Buffer Pool can be invoked from multiple threads in parallel */
 
 typedef struct buffer_s {
     void* start;
     size_t capacity;
 } buffer_t;
 
 static const buffer_t g_nullBuffer = { NULL, 0 };
 
 typedef struct ZSTDMT_bufferPool_s {
     ZSTD_pthread_mutex_t poolMutex;
     size_t bufferSize;
     unsigned totalBuffers;
     unsigned nbBuffers;
     ZSTD_customMem cMem;
     buffer_t bTable[1];   /* variable size */
 } ZSTDMT_bufferPool;
 
 static ZSTDMT_bufferPool* ZSTDMT_createBufferPool(unsigned nbWorkers, ZSTD_customMem cMem)
 {
     unsigned const maxNbBuffers = 2*nbWorkers + 3;
     ZSTDMT_bufferPool* const bufPool = (ZSTDMT_bufferPool*)ZSTD_calloc(
         sizeof(ZSTDMT_bufferPool) + (maxNbBuffers-1) * sizeof(buffer_t), cMem);
     if (bufPool==NULL) return NULL;
     if (ZSTD_pthread_mutex_init(&bufPool->poolMutex, NULL)) {
         ZSTD_free(bufPool, cMem);
         return NULL;
     }
     bufPool->bufferSize = 64 KB;
     bufPool->totalBuffers = maxNbBuffers;
     bufPool->nbBuffers = 0;
     bufPool->cMem = cMem;
     return bufPool;
 }
 
 static void ZSTDMT_freeBufferPool(ZSTDMT_bufferPool* bufPool)
 {
     unsigned u;
     DEBUGLOG(3, "ZSTDMT_freeBufferPool (address:%08X)", (U32)(size_t)bufPool);
     if (!bufPool) return;   /* compatibility with free on NULL */
     for (u=0; utotalBuffers; u++) {
         DEBUGLOG(4, "free buffer %2u (address:%08X)", u, (U32)(size_t)bufPool->bTable[u].start);
         ZSTD_free(bufPool->bTable[u].start, bufPool->cMem);
     }
     ZSTD_pthread_mutex_destroy(&bufPool->poolMutex);
     ZSTD_free(bufPool, bufPool->cMem);
 }
 
 /* only works at initialization, not during compression */
 static size_t ZSTDMT_sizeof_bufferPool(ZSTDMT_bufferPool* bufPool)
 {
     size_t const poolSize = sizeof(*bufPool)
                           + (bufPool->totalBuffers - 1) * sizeof(buffer_t);
     unsigned u;
     size_t totalBufferSize = 0;
     ZSTD_pthread_mutex_lock(&bufPool->poolMutex);
     for (u=0; utotalBuffers; u++)
         totalBufferSize += bufPool->bTable[u].capacity;
     ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
 
     return poolSize + totalBufferSize;
 }
 
 /* ZSTDMT_setBufferSize() :
  * all future buffers provided by this buffer pool will have _at least_ this size
  * note : it's better for all buffers to have same size,
  * as they become freely interchangeable, reducing malloc/free usages and memory fragmentation */
 static void ZSTDMT_setBufferSize(ZSTDMT_bufferPool* const bufPool, size_t const bSize)
 {
     ZSTD_pthread_mutex_lock(&bufPool->poolMutex);
     DEBUGLOG(4, "ZSTDMT_setBufferSize: bSize = %u", (U32)bSize);
     bufPool->bufferSize = bSize;
     ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
 }
 
 
 static ZSTDMT_bufferPool* ZSTDMT_expandBufferPool(ZSTDMT_bufferPool* srcBufPool, U32 nbWorkers)
 {
     unsigned const maxNbBuffers = 2*nbWorkers + 3;
     if (srcBufPool==NULL) return NULL;
     if (srcBufPool->totalBuffers >= maxNbBuffers) /* good enough */
         return srcBufPool;
     /* need a larger buffer pool */
     {   ZSTD_customMem const cMem = srcBufPool->cMem;
         size_t const bSize = srcBufPool->bufferSize;   /* forward parameters */
         ZSTDMT_bufferPool* newBufPool;
         ZSTDMT_freeBufferPool(srcBufPool);
         newBufPool = ZSTDMT_createBufferPool(nbWorkers, cMem);
         if (newBufPool==NULL) return newBufPool;
         ZSTDMT_setBufferSize(newBufPool, bSize);
         return newBufPool;
     }
 }
 
 /** ZSTDMT_getBuffer() :
  *  assumption : bufPool must be valid
  * @return : a buffer, with start pointer and size
  *  note: allocation may fail, in this case, start==NULL and size==0 */
 static buffer_t ZSTDMT_getBuffer(ZSTDMT_bufferPool* bufPool)
 {
     size_t const bSize = bufPool->bufferSize;
     DEBUGLOG(5, "ZSTDMT_getBuffer: bSize = %u", (U32)bufPool->bufferSize);
     ZSTD_pthread_mutex_lock(&bufPool->poolMutex);
     if (bufPool->nbBuffers) {   /* try to use an existing buffer */
         buffer_t const buf = bufPool->bTable[--(bufPool->nbBuffers)];
         size_t const availBufferSize = buf.capacity;
         bufPool->bTable[bufPool->nbBuffers] = g_nullBuffer;
         if ((availBufferSize >= bSize) & ((availBufferSize>>3) <= bSize)) {
             /* large enough, but not too much */
             DEBUGLOG(5, "ZSTDMT_getBuffer: provide buffer %u of size %u",
                         bufPool->nbBuffers, (U32)buf.capacity);
             ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
             return buf;
         }
         /* size conditions not respected : scratch this buffer, create new one */
         DEBUGLOG(5, "ZSTDMT_getBuffer: existing buffer does not meet size conditions => freeing");
         ZSTD_free(buf.start, bufPool->cMem);
     }
     ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
     /* create new buffer */
     DEBUGLOG(5, "ZSTDMT_getBuffer: create a new buffer");
     {   buffer_t buffer;
         void* const start = ZSTD_malloc(bSize, bufPool->cMem);
         buffer.start = start;   /* note : start can be NULL if malloc fails ! */
         buffer.capacity = (start==NULL) ? 0 : bSize;
         if (start==NULL) {
             DEBUGLOG(5, "ZSTDMT_getBuffer: buffer allocation failure !!");
         } else {
             DEBUGLOG(5, "ZSTDMT_getBuffer: created buffer of size %u", (U32)bSize);
         }
         return buffer;
     }
 }
 
 #if ZSTD_RESIZE_SEQPOOL
 /** ZSTDMT_resizeBuffer() :
  * assumption : bufPool must be valid
  * @return : a buffer that is at least the buffer pool buffer size.
  *           If a reallocation happens, the data in the input buffer is copied.
  */
 static buffer_t ZSTDMT_resizeBuffer(ZSTDMT_bufferPool* bufPool, buffer_t buffer)
 {
     size_t const bSize = bufPool->bufferSize;
     if (buffer.capacity < bSize) {
         void* const start = ZSTD_malloc(bSize, bufPool->cMem);
         buffer_t newBuffer;
         newBuffer.start = start;
         newBuffer.capacity = start == NULL ? 0 : bSize;
         if (start != NULL) {
             assert(newBuffer.capacity >= buffer.capacity);
             memcpy(newBuffer.start, buffer.start, buffer.capacity);
             DEBUGLOG(5, "ZSTDMT_resizeBuffer: created buffer of size %u", (U32)bSize);
             return newBuffer;
         }
         DEBUGLOG(5, "ZSTDMT_resizeBuffer: buffer allocation failure !!");
     }
     return buffer;
 }
 #endif
 
 /* store buffer for later re-use, up to pool capacity */
 static void ZSTDMT_releaseBuffer(ZSTDMT_bufferPool* bufPool, buffer_t buf)
 {
     DEBUGLOG(5, "ZSTDMT_releaseBuffer");
     if (buf.start == NULL) return;   /* compatible with release on NULL */
     ZSTD_pthread_mutex_lock(&bufPool->poolMutex);
     if (bufPool->nbBuffers < bufPool->totalBuffers) {
         bufPool->bTable[bufPool->nbBuffers++] = buf;  /* stored for later use */
         DEBUGLOG(5, "ZSTDMT_releaseBuffer: stored buffer of size %u in slot %u",
                     (U32)buf.capacity, (U32)(bufPool->nbBuffers-1));
         ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
         return;
     }
     ZSTD_pthread_mutex_unlock(&bufPool->poolMutex);
     /* Reached bufferPool capacity (should not happen) */
     DEBUGLOG(5, "ZSTDMT_releaseBuffer: pool capacity reached => freeing ");
     ZSTD_free(buf.start, bufPool->cMem);
 }
 
 
 /* =====   Seq Pool Wrapper   ====== */
 
 static rawSeqStore_t kNullRawSeqStore = {NULL, 0, 0, 0};
 
 typedef ZSTDMT_bufferPool ZSTDMT_seqPool;
 
 static size_t ZSTDMT_sizeof_seqPool(ZSTDMT_seqPool* seqPool)
 {
     return ZSTDMT_sizeof_bufferPool(seqPool);
 }
 
 static rawSeqStore_t bufferToSeq(buffer_t buffer)
 {
     rawSeqStore_t seq = {NULL, 0, 0, 0};
     seq.seq = (rawSeq*)buffer.start;
     seq.capacity = buffer.capacity / sizeof(rawSeq);
     return seq;
 }
 
 static buffer_t seqToBuffer(rawSeqStore_t seq)
 {
     buffer_t buffer;
     buffer.start = seq.seq;
     buffer.capacity = seq.capacity * sizeof(rawSeq);
     return buffer;
 }
 
 static rawSeqStore_t ZSTDMT_getSeq(ZSTDMT_seqPool* seqPool)
 {
     if (seqPool->bufferSize == 0) {
         return kNullRawSeqStore;
     }
     return bufferToSeq(ZSTDMT_getBuffer(seqPool));
 }
 
 #if ZSTD_RESIZE_SEQPOOL
 static rawSeqStore_t ZSTDMT_resizeSeq(ZSTDMT_seqPool* seqPool, rawSeqStore_t seq)
 {
   return bufferToSeq(ZSTDMT_resizeBuffer(seqPool, seqToBuffer(seq)));
 }
 #endif
 
 static void ZSTDMT_releaseSeq(ZSTDMT_seqPool* seqPool, rawSeqStore_t seq)
 {
   ZSTDMT_releaseBuffer(seqPool, seqToBuffer(seq));
 }
 
 static void ZSTDMT_setNbSeq(ZSTDMT_seqPool* const seqPool, size_t const nbSeq)
 {
   ZSTDMT_setBufferSize(seqPool, nbSeq * sizeof(rawSeq));
 }
 
 static ZSTDMT_seqPool* ZSTDMT_createSeqPool(unsigned nbWorkers, ZSTD_customMem cMem)
 {
     ZSTDMT_seqPool* const seqPool = ZSTDMT_createBufferPool(nbWorkers, cMem);
     if (seqPool == NULL) return NULL;
     ZSTDMT_setNbSeq(seqPool, 0);
     return seqPool;
 }
 
 static void ZSTDMT_freeSeqPool(ZSTDMT_seqPool* seqPool)
 {
     ZSTDMT_freeBufferPool(seqPool);
 }
 
 static ZSTDMT_seqPool* ZSTDMT_expandSeqPool(ZSTDMT_seqPool* pool, U32 nbWorkers)
 {
     return ZSTDMT_expandBufferPool(pool, nbWorkers);
 }
 
 
 /* =====   CCtx Pool   ===== */
 /* a single CCtx Pool can be invoked from multiple threads in parallel */
 
 typedef struct {
     ZSTD_pthread_mutex_t poolMutex;
     int totalCCtx;
     int availCCtx;
     ZSTD_customMem cMem;
     ZSTD_CCtx* cctx[1];   /* variable size */
 } ZSTDMT_CCtxPool;
 
 /* note : all CCtx borrowed from the pool should be released back to the pool _before_ freeing the pool */
 static void ZSTDMT_freeCCtxPool(ZSTDMT_CCtxPool* pool)
 {
     int cid;
     for (cid=0; cidtotalCCtx; cid++)
         ZSTD_freeCCtx(pool->cctx[cid]);  /* note : compatible with free on NULL */
     ZSTD_pthread_mutex_destroy(&pool->poolMutex);
     ZSTD_free(pool, pool->cMem);
 }
 
 /* ZSTDMT_createCCtxPool() :
  * implies nbWorkers >= 1 , checked by caller ZSTDMT_createCCtx() */
 static ZSTDMT_CCtxPool* ZSTDMT_createCCtxPool(int nbWorkers,
                                               ZSTD_customMem cMem)
 {
     ZSTDMT_CCtxPool* const cctxPool = (ZSTDMT_CCtxPool*) ZSTD_calloc(
         sizeof(ZSTDMT_CCtxPool) + (nbWorkers-1)*sizeof(ZSTD_CCtx*), cMem);
     assert(nbWorkers > 0);
     if (!cctxPool) return NULL;
     if (ZSTD_pthread_mutex_init(&cctxPool->poolMutex, NULL)) {
         ZSTD_free(cctxPool, cMem);
         return NULL;
     }
     cctxPool->cMem = cMem;
     cctxPool->totalCCtx = nbWorkers;
     cctxPool->availCCtx = 1;   /* at least one cctx for single-thread mode */
     cctxPool->cctx[0] = ZSTD_createCCtx_advanced(cMem);
     if (!cctxPool->cctx[0]) { ZSTDMT_freeCCtxPool(cctxPool); return NULL; }
     DEBUGLOG(3, "cctxPool created, with %u workers", nbWorkers);
     return cctxPool;
 }
 
 static ZSTDMT_CCtxPool* ZSTDMT_expandCCtxPool(ZSTDMT_CCtxPool* srcPool,
                                               int nbWorkers)
 {
     if (srcPool==NULL) return NULL;
     if (nbWorkers <= srcPool->totalCCtx) return srcPool;   /* good enough */
     /* need a larger cctx pool */
     {   ZSTD_customMem const cMem = srcPool->cMem;
         ZSTDMT_freeCCtxPool(srcPool);
         return ZSTDMT_createCCtxPool(nbWorkers, cMem);
     }
 }
 
 /* only works during initialization phase, not during compression */
 static size_t ZSTDMT_sizeof_CCtxPool(ZSTDMT_CCtxPool* cctxPool)
 {
     ZSTD_pthread_mutex_lock(&cctxPool->poolMutex);
     {   unsigned const nbWorkers = cctxPool->totalCCtx;
         size_t const poolSize = sizeof(*cctxPool)
                                 + (nbWorkers-1) * sizeof(ZSTD_CCtx*);
         unsigned u;
         size_t totalCCtxSize = 0;
         for (u=0; ucctx[u]);
         }
         ZSTD_pthread_mutex_unlock(&cctxPool->poolMutex);
         assert(nbWorkers > 0);
         return poolSize + totalCCtxSize;
     }
 }
 
 static ZSTD_CCtx* ZSTDMT_getCCtx(ZSTDMT_CCtxPool* cctxPool)
 {
     DEBUGLOG(5, "ZSTDMT_getCCtx");
     ZSTD_pthread_mutex_lock(&cctxPool->poolMutex);
     if (cctxPool->availCCtx) {
         cctxPool->availCCtx--;
         {   ZSTD_CCtx* const cctx = cctxPool->cctx[cctxPool->availCCtx];
             ZSTD_pthread_mutex_unlock(&cctxPool->poolMutex);
             return cctx;
     }   }
     ZSTD_pthread_mutex_unlock(&cctxPool->poolMutex);
     DEBUGLOG(5, "create one more CCtx");
     return ZSTD_createCCtx_advanced(cctxPool->cMem);   /* note : can be NULL, when creation fails ! */
 }
 
 static void ZSTDMT_releaseCCtx(ZSTDMT_CCtxPool* pool, ZSTD_CCtx* cctx)
 {
     if (cctx==NULL) return;   /* compatibility with release on NULL */
     ZSTD_pthread_mutex_lock(&pool->poolMutex);
     if (pool->availCCtx < pool->totalCCtx)
         pool->cctx[pool->availCCtx++] = cctx;
     else {
         /* pool overflow : should not happen, since totalCCtx==nbWorkers */
         DEBUGLOG(4, "CCtx pool overflow : free cctx");
         ZSTD_freeCCtx(cctx);
     }
     ZSTD_pthread_mutex_unlock(&pool->poolMutex);
 }
 
 /* ====   Serial State   ==== */
 
 typedef struct {
     void const* start;
     size_t size;
 } range_t;
 
 typedef struct {
     /* All variables in the struct are protected by mutex. */
     ZSTD_pthread_mutex_t mutex;
     ZSTD_pthread_cond_t cond;
     ZSTD_CCtx_params params;
     ldmState_t ldmState;
     XXH64_state_t xxhState;
     unsigned nextJobID;
     /* Protects ldmWindow.
      * Must be acquired after the main mutex when acquiring both.
      */
     ZSTD_pthread_mutex_t ldmWindowMutex;
     ZSTD_pthread_cond_t ldmWindowCond;  /* Signaled when ldmWindow is updated */
     ZSTD_window_t ldmWindow;  /* A thread-safe copy of ldmState.window */
 } serialState_t;
 
 static int ZSTDMT_serialState_reset(serialState_t* serialState, ZSTDMT_seqPool* seqPool, ZSTD_CCtx_params params, size_t jobSize)
 {
     /* Adjust parameters */
     if (params.ldmParams.enableLdm) {
         DEBUGLOG(4, "LDM window size = %u KB", (1U << params.cParams.windowLog) >> 10);
         ZSTD_ldm_adjustParameters(¶ms.ldmParams, ¶ms.cParams);
         assert(params.ldmParams.hashLog >= params.ldmParams.bucketSizeLog);
         assert(params.ldmParams.hashRateLog < 32);
         serialState->ldmState.hashPower =
                 ZSTD_rollingHash_primePower(params.ldmParams.minMatchLength);
     } else {
         memset(¶ms.ldmParams, 0, sizeof(params.ldmParams));
     }
     serialState->nextJobID = 0;
     if (params.fParams.checksumFlag)
         XXH64_reset(&serialState->xxhState, 0);
     if (params.ldmParams.enableLdm) {
         ZSTD_customMem cMem = params.customMem;
         unsigned const hashLog = params.ldmParams.hashLog;
         size_t const hashSize = ((size_t)1 << hashLog) * sizeof(ldmEntry_t);
         unsigned const bucketLog =
             params.ldmParams.hashLog - params.ldmParams.bucketSizeLog;
         size_t const bucketSize = (size_t)1 << bucketLog;
         unsigned const prevBucketLog =
             serialState->params.ldmParams.hashLog -
             serialState->params.ldmParams.bucketSizeLog;
         /* Size the seq pool tables */
         ZSTDMT_setNbSeq(seqPool, ZSTD_ldm_getMaxNbSeq(params.ldmParams, jobSize));
         /* Reset the window */
         ZSTD_window_clear(&serialState->ldmState.window);
         serialState->ldmWindow = serialState->ldmState.window;
         /* Resize tables and output space if necessary. */
         if (serialState->ldmState.hashTable == NULL || serialState->params.ldmParams.hashLog < hashLog) {
             ZSTD_free(serialState->ldmState.hashTable, cMem);
             serialState->ldmState.hashTable = (ldmEntry_t*)ZSTD_malloc(hashSize, cMem);
         }
         if (serialState->ldmState.bucketOffsets == NULL || prevBucketLog < bucketLog) {
             ZSTD_free(serialState->ldmState.bucketOffsets, cMem);
             serialState->ldmState.bucketOffsets = (BYTE*)ZSTD_malloc(bucketSize, cMem);
         }
         if (!serialState->ldmState.hashTable || !serialState->ldmState.bucketOffsets)
             return 1;
         /* Zero the tables */
         memset(serialState->ldmState.hashTable, 0, hashSize);
         memset(serialState->ldmState.bucketOffsets, 0, bucketSize);
     }
     serialState->params = params;
     serialState->params.jobSize = (U32)jobSize;
     return 0;
 }
 
 static int ZSTDMT_serialState_init(serialState_t* serialState)
 {
     int initError = 0;
     memset(serialState, 0, sizeof(*serialState));
     initError |= ZSTD_pthread_mutex_init(&serialState->mutex, NULL);
     initError |= ZSTD_pthread_cond_init(&serialState->cond, NULL);
     initError |= ZSTD_pthread_mutex_init(&serialState->ldmWindowMutex, NULL);
     initError |= ZSTD_pthread_cond_init(&serialState->ldmWindowCond, NULL);
     return initError;
 }
 
 static void ZSTDMT_serialState_free(serialState_t* serialState)
 {
     ZSTD_customMem cMem = serialState->params.customMem;
     ZSTD_pthread_mutex_destroy(&serialState->mutex);
     ZSTD_pthread_cond_destroy(&serialState->cond);
     ZSTD_pthread_mutex_destroy(&serialState->ldmWindowMutex);
     ZSTD_pthread_cond_destroy(&serialState->ldmWindowCond);
     ZSTD_free(serialState->ldmState.hashTable, cMem);
     ZSTD_free(serialState->ldmState.bucketOffsets, cMem);
 }
 
 static void ZSTDMT_serialState_update(serialState_t* serialState,
                                       ZSTD_CCtx* jobCCtx, rawSeqStore_t seqStore,
                                       range_t src, unsigned jobID)
 {
     /* Wait for our turn */
     ZSTD_PTHREAD_MUTEX_LOCK(&serialState->mutex);
     while (serialState->nextJobID < jobID) {
         DEBUGLOG(5, "wait for serialState->cond");
         ZSTD_pthread_cond_wait(&serialState->cond, &serialState->mutex);
     }
     /* A future job may error and skip our job */
     if (serialState->nextJobID == jobID) {
         /* It is now our turn, do any processing necessary */
         if (serialState->params.ldmParams.enableLdm) {
             size_t error;
             assert(seqStore.seq != NULL && seqStore.pos == 0 &&
                    seqStore.size == 0 && seqStore.capacity > 0);
             assert(src.size <= serialState->params.jobSize);
             ZSTD_window_update(&serialState->ldmState.window, src.start, src.size);
             error = ZSTD_ldm_generateSequences(
                 &serialState->ldmState, &seqStore,
                 &serialState->params.ldmParams, src.start, src.size);
             /* We provide a large enough buffer to never fail. */
             assert(!ZSTD_isError(error)); (void)error;
             /* Update ldmWindow to match the ldmState.window and signal the main
              * thread if it is waiting for a buffer.
              */
             ZSTD_PTHREAD_MUTEX_LOCK(&serialState->ldmWindowMutex);
             serialState->ldmWindow = serialState->ldmState.window;
             ZSTD_pthread_cond_signal(&serialState->ldmWindowCond);
             ZSTD_pthread_mutex_unlock(&serialState->ldmWindowMutex);
         }
         if (serialState->params.fParams.checksumFlag && src.size > 0)
             XXH64_update(&serialState->xxhState, src.start, src.size);
     }
     /* Now it is the next jobs turn */
     serialState->nextJobID++;
     ZSTD_pthread_cond_broadcast(&serialState->cond);
     ZSTD_pthread_mutex_unlock(&serialState->mutex);
 
     if (seqStore.size > 0) {
         size_t const err = ZSTD_referenceExternalSequences(
             jobCCtx, seqStore.seq, seqStore.size);
         assert(serialState->params.ldmParams.enableLdm);
         assert(!ZSTD_isError(err));
         (void)err;
     }
 }
 
 static void ZSTDMT_serialState_ensureFinished(serialState_t* serialState,
                                               unsigned jobID, size_t cSize)
 {
     ZSTD_PTHREAD_MUTEX_LOCK(&serialState->mutex);
     if (serialState->nextJobID <= jobID) {
         assert(ZSTD_isError(cSize)); (void)cSize;
         DEBUGLOG(5, "Skipping past job %u because of error", jobID);
         serialState->nextJobID = jobID + 1;
         ZSTD_pthread_cond_broadcast(&serialState->cond);
 
         ZSTD_PTHREAD_MUTEX_LOCK(&serialState->ldmWindowMutex);
         ZSTD_window_clear(&serialState->ldmWindow);
         ZSTD_pthread_cond_signal(&serialState->ldmWindowCond);
         ZSTD_pthread_mutex_unlock(&serialState->ldmWindowMutex);
     }
     ZSTD_pthread_mutex_unlock(&serialState->mutex);
 
 }
 
 
 /* ------------------------------------------ */
 /* =====          Worker thread         ===== */
 /* ------------------------------------------ */
 
 static const range_t kNullRange = { NULL, 0 };
 
 typedef struct {
     size_t   consumed;                   /* SHARED - set0 by mtctx, then modified by worker AND read by mtctx */
     size_t   cSize;                      /* SHARED - set0 by mtctx, then modified by worker AND read by mtctx, then set0 by mtctx */
     ZSTD_pthread_mutex_t job_mutex;      /* Thread-safe - used by mtctx and worker */
     ZSTD_pthread_cond_t job_cond;        /* Thread-safe - used by mtctx and worker */
     ZSTDMT_CCtxPool* cctxPool;           /* Thread-safe - used by mtctx and (all) workers */
     ZSTDMT_bufferPool* bufPool;          /* Thread-safe - used by mtctx and (all) workers */
     ZSTDMT_seqPool* seqPool;             /* Thread-safe - used by mtctx and (all) workers */
     serialState_t* serial;               /* Thread-safe - used by mtctx and (all) workers */
     buffer_t dstBuff;                    /* set by worker (or mtctx), then read by worker & mtctx, then modified by mtctx => no barrier */
     range_t prefix;                      /* set by mtctx, then read by worker & mtctx => no barrier */
     range_t src;                         /* set by mtctx, then read by worker & mtctx => no barrier */
     unsigned jobID;                      /* set by mtctx, then read by worker => no barrier */
     unsigned firstJob;                   /* set by mtctx, then read by worker => no barrier */
     unsigned lastJob;                    /* set by mtctx, then read by worker => no barrier */
     ZSTD_CCtx_params params;             /* set by mtctx, then read by worker => no barrier */
     const ZSTD_CDict* cdict;             /* set by mtctx, then read by worker => no barrier */
     unsigned long long fullFrameSize;    /* set by mtctx, then read by worker => no barrier */
     size_t   dstFlushed;                 /* used only by mtctx */
     unsigned frameChecksumNeeded;        /* used only by mtctx */
 } ZSTDMT_jobDescription;
 
 #define JOB_ERROR(e) {                          \
     ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);   \
     job->cSize = e;                             \
     ZSTD_pthread_mutex_unlock(&job->job_mutex); \
     goto _endJob;                               \
 }
 
 /* ZSTDMT_compressionJob() is a POOL_function type */
 static void ZSTDMT_compressionJob(void* jobDescription)
 {
     ZSTDMT_jobDescription* const job = (ZSTDMT_jobDescription*)jobDescription;
     ZSTD_CCtx_params jobParams = job->params;   /* do not modify job->params ! copy it, modify the copy */
     ZSTD_CCtx* const cctx = ZSTDMT_getCCtx(job->cctxPool);
     rawSeqStore_t rawSeqStore = ZSTDMT_getSeq(job->seqPool);
     buffer_t dstBuff = job->dstBuff;
     size_t lastCBlockSize = 0;
 
     /* resources */
     if (cctx==NULL) JOB_ERROR(ERROR(memory_allocation));
     if (dstBuff.start == NULL) {   /* streaming job : doesn't provide a dstBuffer */
         dstBuff = ZSTDMT_getBuffer(job->bufPool);
         if (dstBuff.start==NULL) JOB_ERROR(ERROR(memory_allocation));
         job->dstBuff = dstBuff;   /* this value can be read in ZSTDMT_flush, when it copies the whole job */
     }
     if (jobParams.ldmParams.enableLdm && rawSeqStore.seq == NULL)
         JOB_ERROR(ERROR(memory_allocation));
 
     /* Don't compute the checksum for chunks, since we compute it externally,
      * but write it in the header.
      */
     if (job->jobID != 0) jobParams.fParams.checksumFlag = 0;
     /* Don't run LDM for the chunks, since we handle it externally */
     jobParams.ldmParams.enableLdm = 0;
 
 
     /* init */
     if (job->cdict) {
-        size_t const initError = ZSTD_compressBegin_advanced_internal(cctx, NULL, 0, ZSTD_dct_auto, ZSTD_dtlm_fast, job->cdict, jobParams, job->fullFrameSize);
+        size_t const initError = ZSTD_compressBegin_advanced_internal(cctx, NULL, 0, ZSTD_dct_auto, ZSTD_dtlm_fast, job->cdict, &jobParams, job->fullFrameSize);
         assert(job->firstJob);  /* only allowed for first job */
         if (ZSTD_isError(initError)) JOB_ERROR(initError);
     } else {  /* srcStart points at reloaded section */
         U64 const pledgedSrcSize = job->firstJob ? job->fullFrameSize : job->src.size;
         {   size_t const forceWindowError = ZSTD_CCtxParams_setParameter(&jobParams, ZSTD_c_forceMaxWindow, !job->firstJob);
             if (ZSTD_isError(forceWindowError)) JOB_ERROR(forceWindowError);
         }
         {   size_t const initError = ZSTD_compressBegin_advanced_internal(cctx,
                                         job->prefix.start, job->prefix.size, ZSTD_dct_rawContent, /* load dictionary in "content-only" mode (no header analysis) */
                                         ZSTD_dtlm_fast,
                                         NULL, /*cdict*/
-                                        jobParams, pledgedSrcSize);
+                                        &jobParams, pledgedSrcSize);
             if (ZSTD_isError(initError)) JOB_ERROR(initError);
     }   }
 
     /* Perform serial step as early as possible, but after CCtx initialization */
     ZSTDMT_serialState_update(job->serial, cctx, rawSeqStore, job->src, job->jobID);
 
     if (!job->firstJob) {  /* flush and overwrite frame header when it's not first job */
         size_t const hSize = ZSTD_compressContinue(cctx, dstBuff.start, dstBuff.capacity, job->src.start, 0);
         if (ZSTD_isError(hSize)) JOB_ERROR(hSize);
         DEBUGLOG(5, "ZSTDMT_compressionJob: flush and overwrite %u bytes of frame header (not first job)", (U32)hSize);
         ZSTD_invalidateRepCodes(cctx);
     }
 
     /* compress */
     {   size_t const chunkSize = 4*ZSTD_BLOCKSIZE_MAX;
         int const nbChunks = (int)((job->src.size + (chunkSize-1)) / chunkSize);
         const BYTE* ip = (const BYTE*) job->src.start;
         BYTE* const ostart = (BYTE*)dstBuff.start;
         BYTE* op = ostart;
         BYTE* oend = op + dstBuff.capacity;
         int chunkNb;
         if (sizeof(size_t) > sizeof(int)) assert(job->src.size < ((size_t)INT_MAX) * chunkSize);   /* check overflow */
         DEBUGLOG(5, "ZSTDMT_compressionJob: compress %u bytes in %i blocks", (U32)job->src.size, nbChunks);
         assert(job->cSize == 0);
         for (chunkNb = 1; chunkNb < nbChunks; chunkNb++) {
             size_t const cSize = ZSTD_compressContinue(cctx, op, oend-op, ip, chunkSize);
             if (ZSTD_isError(cSize)) JOB_ERROR(cSize);
             ip += chunkSize;
             op += cSize; assert(op < oend);
             /* stats */
             ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);
             job->cSize += cSize;
             job->consumed = chunkSize * chunkNb;
             DEBUGLOG(5, "ZSTDMT_compressionJob: compress new block : cSize==%u bytes (total: %u)",
                         (U32)cSize, (U32)job->cSize);
             ZSTD_pthread_cond_signal(&job->job_cond);   /* warns some more data is ready to be flushed */
             ZSTD_pthread_mutex_unlock(&job->job_mutex);
         }
         /* last block */
         assert(chunkSize > 0);
         assert((chunkSize & (chunkSize - 1)) == 0);  /* chunkSize must be power of 2 for mask==(chunkSize-1) to work */
         if ((nbChunks > 0) | job->lastJob /*must output a "last block" flag*/ ) {
             size_t const lastBlockSize1 = job->src.size & (chunkSize-1);
             size_t const lastBlockSize = ((lastBlockSize1==0) & (job->src.size>=chunkSize)) ? chunkSize : lastBlockSize1;
             size_t const cSize = (job->lastJob) ?
                  ZSTD_compressEnd     (cctx, op, oend-op, ip, lastBlockSize) :
                  ZSTD_compressContinue(cctx, op, oend-op, ip, lastBlockSize);
             if (ZSTD_isError(cSize)) JOB_ERROR(cSize);
             lastCBlockSize = cSize;
     }   }
 
 _endJob:
     ZSTDMT_serialState_ensureFinished(job->serial, job->jobID, job->cSize);
     if (job->prefix.size > 0)
         DEBUGLOG(5, "Finished with prefix: %zx", (size_t)job->prefix.start);
     DEBUGLOG(5, "Finished with source: %zx", (size_t)job->src.start);
     /* release resources */
     ZSTDMT_releaseSeq(job->seqPool, rawSeqStore);
     ZSTDMT_releaseCCtx(job->cctxPool, cctx);
     /* report */
     ZSTD_PTHREAD_MUTEX_LOCK(&job->job_mutex);
     if (ZSTD_isError(job->cSize)) assert(lastCBlockSize == 0);
     job->cSize += lastCBlockSize;
     job->consumed = job->src.size;  /* when job->consumed == job->src.size , compression job is presumed completed */
     ZSTD_pthread_cond_signal(&job->job_cond);
     ZSTD_pthread_mutex_unlock(&job->job_mutex);
 }
 
 
 /* ------------------------------------------ */
 /* =====   Multi-threaded compression   ===== */
 /* ------------------------------------------ */
 
 typedef struct {
     range_t prefix;         /* read-only non-owned prefix buffer */
     buffer_t buffer;
     size_t filled;
 } inBuff_t;
 
 typedef struct {
   BYTE* buffer;     /* The round input buffer. All jobs get references
                      * to pieces of the buffer. ZSTDMT_tryGetInputRange()
                      * handles handing out job input buffers, and makes
                      * sure it doesn't overlap with any pieces still in use.
                      */
   size_t capacity;  /* The capacity of buffer. */
   size_t pos;       /* The position of the current inBuff in the round
                      * buffer. Updated past the end if the inBuff once
                      * the inBuff is sent to the worker thread.
                      * pos <= capacity.
                      */
 } roundBuff_t;
 
 static const roundBuff_t kNullRoundBuff = {NULL, 0, 0};
 
 #define RSYNC_LENGTH 32
 
 typedef struct {
   U64 hash;
   U64 hitMask;
   U64 primePower;
 } rsyncState_t;
 
 struct ZSTDMT_CCtx_s {
     POOL_ctx* factory;
     ZSTDMT_jobDescription* jobs;
     ZSTDMT_bufferPool* bufPool;
     ZSTDMT_CCtxPool* cctxPool;
     ZSTDMT_seqPool* seqPool;
     ZSTD_CCtx_params params;
     size_t targetSectionSize;
     size_t targetPrefixSize;
     int jobReady;        /* 1 => one job is already prepared, but pool has shortage of workers. Don't create a new job. */
     inBuff_t inBuff;
     roundBuff_t roundBuff;
     serialState_t serial;
     rsyncState_t rsync;
     unsigned singleBlockingThread;
     unsigned jobIDMask;
     unsigned doneJobID;
     unsigned nextJobID;
     unsigned frameEnded;
     unsigned allJobsCompleted;
     unsigned long long frameContentSize;
     unsigned long long consumed;
     unsigned long long produced;
     ZSTD_customMem cMem;
     ZSTD_CDict* cdictLocal;
     const ZSTD_CDict* cdict;
 };
 
 static void ZSTDMT_freeJobsTable(ZSTDMT_jobDescription* jobTable, U32 nbJobs, ZSTD_customMem cMem)
 {
     U32 jobNb;
     if (jobTable == NULL) return;
     for (jobNb=0; jobNb mtctx->jobIDMask+1) {  /* need more job capacity */
         ZSTDMT_freeJobsTable(mtctx->jobs, mtctx->jobIDMask+1, mtctx->cMem);
         mtctx->jobIDMask = 0;
         mtctx->jobs = ZSTDMT_createJobsTable(&nbJobs, mtctx->cMem);
         if (mtctx->jobs==NULL) return ERROR(memory_allocation);
         assert((nbJobs != 0) && ((nbJobs & (nbJobs - 1)) == 0));  /* ensure nbJobs is a power of 2 */
         mtctx->jobIDMask = nbJobs - 1;
     }
     return 0;
 }
 
 
 /* ZSTDMT_CCtxParam_setNbWorkers():
  * Internal use only */
 size_t ZSTDMT_CCtxParam_setNbWorkers(ZSTD_CCtx_params* params, unsigned nbWorkers)
 {
     return ZSTD_CCtxParams_setParameter(params, ZSTD_c_nbWorkers, (int)nbWorkers);
 }
 
 MEM_STATIC ZSTDMT_CCtx* ZSTDMT_createCCtx_advanced_internal(unsigned nbWorkers, ZSTD_customMem cMem)
 {
     ZSTDMT_CCtx* mtctx;
     U32 nbJobs = nbWorkers + 2;
     int initError;
     DEBUGLOG(3, "ZSTDMT_createCCtx_advanced (nbWorkers = %u)", nbWorkers);
 
     if (nbWorkers < 1) return NULL;
     nbWorkers = MIN(nbWorkers , ZSTDMT_NBWORKERS_MAX);
     if ((cMem.customAlloc!=NULL) ^ (cMem.customFree!=NULL))
         /* invalid custom allocator */
         return NULL;
 
     mtctx = (ZSTDMT_CCtx*) ZSTD_calloc(sizeof(ZSTDMT_CCtx), cMem);
     if (!mtctx) return NULL;
     ZSTDMT_CCtxParam_setNbWorkers(&mtctx->params, nbWorkers);
     mtctx->cMem = cMem;
     mtctx->allJobsCompleted = 1;
     mtctx->factory = POOL_create_advanced(nbWorkers, 0, cMem);
     mtctx->jobs = ZSTDMT_createJobsTable(&nbJobs, cMem);
     assert(nbJobs > 0); assert((nbJobs & (nbJobs - 1)) == 0);  /* ensure nbJobs is a power of 2 */
     mtctx->jobIDMask = nbJobs - 1;
     mtctx->bufPool = ZSTDMT_createBufferPool(nbWorkers, cMem);
     mtctx->cctxPool = ZSTDMT_createCCtxPool(nbWorkers, cMem);
     mtctx->seqPool = ZSTDMT_createSeqPool(nbWorkers, cMem);
     initError = ZSTDMT_serialState_init(&mtctx->serial);
     mtctx->roundBuff = kNullRoundBuff;
     if (!mtctx->factory | !mtctx->jobs | !mtctx->bufPool | !mtctx->cctxPool | !mtctx->seqPool | initError) {
         ZSTDMT_freeCCtx(mtctx);
         return NULL;
     }
     DEBUGLOG(3, "mt_cctx created, for %u threads", nbWorkers);
     return mtctx;
 }
 
 ZSTDMT_CCtx* ZSTDMT_createCCtx_advanced(unsigned nbWorkers, ZSTD_customMem cMem)
 {
 #ifdef ZSTD_MULTITHREAD
     return ZSTDMT_createCCtx_advanced_internal(nbWorkers, cMem);
 #else
     (void)nbWorkers;
     (void)cMem;
     return NULL;
 #endif
 }
 
 ZSTDMT_CCtx* ZSTDMT_createCCtx(unsigned nbWorkers)
 {
     return ZSTDMT_createCCtx_advanced(nbWorkers, ZSTD_defaultCMem);
 }
 
 
 /* ZSTDMT_releaseAllJobResources() :
  * note : ensure all workers are killed first ! */
 static void ZSTDMT_releaseAllJobResources(ZSTDMT_CCtx* mtctx)
 {
     unsigned jobID;
     DEBUGLOG(3, "ZSTDMT_releaseAllJobResources");
     for (jobID=0; jobID <= mtctx->jobIDMask; jobID++) {
+        /* Copy the mutex/cond out */
+        ZSTD_pthread_mutex_t const mutex = mtctx->jobs[jobID].job_mutex;
+        ZSTD_pthread_cond_t const cond = mtctx->jobs[jobID].job_cond;
+
         DEBUGLOG(4, "job%02u: release dst address %08X", jobID, (U32)(size_t)mtctx->jobs[jobID].dstBuff.start);
         ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[jobID].dstBuff);
-        mtctx->jobs[jobID].dstBuff = g_nullBuffer;
-        mtctx->jobs[jobID].cSize = 0;
+
+        /* Clear the job description, but keep the mutex/cond */
+        memset(&mtctx->jobs[jobID], 0, sizeof(mtctx->jobs[jobID]));
+        mtctx->jobs[jobID].job_mutex = mutex;
+        mtctx->jobs[jobID].job_cond = cond;
     }
-    memset(mtctx->jobs, 0, (mtctx->jobIDMask+1)*sizeof(ZSTDMT_jobDescription));
     mtctx->inBuff.buffer = g_nullBuffer;
     mtctx->inBuff.filled = 0;
     mtctx->allJobsCompleted = 1;
 }
 
 static void ZSTDMT_waitForAllJobsCompleted(ZSTDMT_CCtx* mtctx)
 {
     DEBUGLOG(4, "ZSTDMT_waitForAllJobsCompleted");
     while (mtctx->doneJobID < mtctx->nextJobID) {
         unsigned const jobID = mtctx->doneJobID & mtctx->jobIDMask;
         ZSTD_PTHREAD_MUTEX_LOCK(&mtctx->jobs[jobID].job_mutex);
         while (mtctx->jobs[jobID].consumed < mtctx->jobs[jobID].src.size) {
             DEBUGLOG(4, "waiting for jobCompleted signal from job %u", mtctx->doneJobID);   /* we want to block when waiting for data to flush */
             ZSTD_pthread_cond_wait(&mtctx->jobs[jobID].job_cond, &mtctx->jobs[jobID].job_mutex);
         }
         ZSTD_pthread_mutex_unlock(&mtctx->jobs[jobID].job_mutex);
         mtctx->doneJobID++;
     }
 }
 
 size_t ZSTDMT_freeCCtx(ZSTDMT_CCtx* mtctx)
 {
     if (mtctx==NULL) return 0;   /* compatible with free on NULL */
     POOL_free(mtctx->factory);   /* stop and free worker threads */
     ZSTDMT_releaseAllJobResources(mtctx);  /* release job resources into pools first */
     ZSTDMT_freeJobsTable(mtctx->jobs, mtctx->jobIDMask+1, mtctx->cMem);
     ZSTDMT_freeBufferPool(mtctx->bufPool);
     ZSTDMT_freeCCtxPool(mtctx->cctxPool);
     ZSTDMT_freeSeqPool(mtctx->seqPool);
     ZSTDMT_serialState_free(&mtctx->serial);
     ZSTD_freeCDict(mtctx->cdictLocal);
     if (mtctx->roundBuff.buffer)
         ZSTD_free(mtctx->roundBuff.buffer, mtctx->cMem);
     ZSTD_free(mtctx, mtctx->cMem);
     return 0;
 }
 
 size_t ZSTDMT_sizeof_CCtx(ZSTDMT_CCtx* mtctx)
 {
     if (mtctx == NULL) return 0;   /* supports sizeof NULL */
     return sizeof(*mtctx)
             + POOL_sizeof(mtctx->factory)
             + ZSTDMT_sizeof_bufferPool(mtctx->bufPool)
             + (mtctx->jobIDMask+1) * sizeof(ZSTDMT_jobDescription)
             + ZSTDMT_sizeof_CCtxPool(mtctx->cctxPool)
             + ZSTDMT_sizeof_seqPool(mtctx->seqPool)
             + ZSTD_sizeof_CDict(mtctx->cdictLocal)
             + mtctx->roundBuff.capacity;
 }
 
 /* Internal only */
 size_t
 ZSTDMT_CCtxParam_setMTCtxParameter(ZSTD_CCtx_params* params,
                                    ZSTDMT_parameter parameter,
                                    int value)
 {
     DEBUGLOG(4, "ZSTDMT_CCtxParam_setMTCtxParameter");
     switch(parameter)
     {
     case ZSTDMT_p_jobSize :
         DEBUGLOG(4, "ZSTDMT_CCtxParam_setMTCtxParameter : set jobSize to %i", value);
         return ZSTD_CCtxParams_setParameter(params, ZSTD_c_jobSize, value);
     case ZSTDMT_p_overlapLog :
         DEBUGLOG(4, "ZSTDMT_p_overlapLog : %i", value);
         return ZSTD_CCtxParams_setParameter(params, ZSTD_c_overlapLog, value);
     case ZSTDMT_p_rsyncable :
         DEBUGLOG(4, "ZSTD_p_rsyncable : %i", value);
         return ZSTD_CCtxParams_setParameter(params, ZSTD_c_rsyncable, value);
     default :
         return ERROR(parameter_unsupported);
     }
 }
 
 size_t ZSTDMT_setMTCtxParameter(ZSTDMT_CCtx* mtctx, ZSTDMT_parameter parameter, int value)
 {
     DEBUGLOG(4, "ZSTDMT_setMTCtxParameter");
     return ZSTDMT_CCtxParam_setMTCtxParameter(&mtctx->params, parameter, value);
 }
 
 size_t ZSTDMT_getMTCtxParameter(ZSTDMT_CCtx* mtctx, ZSTDMT_parameter parameter, int* value)
 {
     switch (parameter) {
     case ZSTDMT_p_jobSize:
         return ZSTD_CCtxParams_getParameter(&mtctx->params, ZSTD_c_jobSize, value);
     case ZSTDMT_p_overlapLog:
         return ZSTD_CCtxParams_getParameter(&mtctx->params, ZSTD_c_overlapLog, value);
     case ZSTDMT_p_rsyncable:
         return ZSTD_CCtxParams_getParameter(&mtctx->params, ZSTD_c_rsyncable, value);
     default:
         return ERROR(parameter_unsupported);
     }
 }
 
 /* Sets parameters relevant to the compression job,
  * initializing others to default values. */
-static ZSTD_CCtx_params ZSTDMT_initJobCCtxParams(ZSTD_CCtx_params const params)
+static ZSTD_CCtx_params ZSTDMT_initJobCCtxParams(const ZSTD_CCtx_params* params)
 {
-    ZSTD_CCtx_params jobParams = params;
+    ZSTD_CCtx_params jobParams = *params;
     /* Clear parameters related to multithreading */
     jobParams.forceWindow = 0;
     jobParams.nbWorkers = 0;
     jobParams.jobSize = 0;
     jobParams.overlapLog = 0;
     jobParams.rsyncable = 0;
     memset(&jobParams.ldmParams, 0, sizeof(ldmParams_t));
     memset(&jobParams.customMem, 0, sizeof(ZSTD_customMem));
     return jobParams;
 }
 
 
 /* ZSTDMT_resize() :
  * @return : error code if fails, 0 on success */
 static size_t ZSTDMT_resize(ZSTDMT_CCtx* mtctx, unsigned nbWorkers)
 {
     if (POOL_resize(mtctx->factory, nbWorkers)) return ERROR(memory_allocation);
     FORWARD_IF_ERROR( ZSTDMT_expandJobsTable(mtctx, nbWorkers) );
     mtctx->bufPool = ZSTDMT_expandBufferPool(mtctx->bufPool, nbWorkers);
     if (mtctx->bufPool == NULL) return ERROR(memory_allocation);
     mtctx->cctxPool = ZSTDMT_expandCCtxPool(mtctx->cctxPool, nbWorkers);
     if (mtctx->cctxPool == NULL) return ERROR(memory_allocation);
     mtctx->seqPool = ZSTDMT_expandSeqPool(mtctx->seqPool, nbWorkers);
     if (mtctx->seqPool == NULL) return ERROR(memory_allocation);
     ZSTDMT_CCtxParam_setNbWorkers(&mtctx->params, nbWorkers);
     return 0;
 }
 
 
 /*! ZSTDMT_updateCParams_whileCompressing() :
  *  Updates a selected set of compression parameters, remaining compatible with currently active frame.
  *  New parameters will be applied to next compression job. */
 void ZSTDMT_updateCParams_whileCompressing(ZSTDMT_CCtx* mtctx, const ZSTD_CCtx_params* cctxParams)
 {
     U32 const saved_wlog = mtctx->params.cParams.windowLog;   /* Do not modify windowLog while compressing */
     int const compressionLevel = cctxParams->compressionLevel;
     DEBUGLOG(5, "ZSTDMT_updateCParams_whileCompressing (level:%i)",
                 compressionLevel);
     mtctx->params.compressionLevel = compressionLevel;
     {   ZSTD_compressionParameters cParams = ZSTD_getCParamsFromCCtxParams(cctxParams, 0, 0);
         cParams.windowLog = saved_wlog;
         mtctx->params.cParams = cParams;
     }
 }
 
 /* ZSTDMT_getFrameProgression():
  * tells how much data has been consumed (input) and produced (output) for current frame.
  * able to count progression inside worker threads.
  * Note : mutex will be acquired during statistics collection inside workers. */
 ZSTD_frameProgression ZSTDMT_getFrameProgression(ZSTDMT_CCtx* mtctx)
 {
     ZSTD_frameProgression fps;
     DEBUGLOG(5, "ZSTDMT_getFrameProgression");
     fps.ingested = mtctx->consumed + mtctx->inBuff.filled;
     fps.consumed = mtctx->consumed;
     fps.produced = fps.flushed = mtctx->produced;
     fps.currentJobID = mtctx->nextJobID;
     fps.nbActiveWorkers = 0;
     {   unsigned jobNb;
         unsigned lastJobNb = mtctx->nextJobID + mtctx->jobReady; assert(mtctx->jobReady <= 1);
         DEBUGLOG(6, "ZSTDMT_getFrameProgression: jobs: from %u to <%u (jobReady:%u)",
                     mtctx->doneJobID, lastJobNb, mtctx->jobReady)
         for (jobNb = mtctx->doneJobID ; jobNb < lastJobNb ; jobNb++) {
             unsigned const wJobID = jobNb & mtctx->jobIDMask;
             ZSTDMT_jobDescription* jobPtr = &mtctx->jobs[wJobID];
             ZSTD_pthread_mutex_lock(&jobPtr->job_mutex);
             {   size_t const cResult = jobPtr->cSize;
                 size_t const produced = ZSTD_isError(cResult) ? 0 : cResult;
                 size_t const flushed = ZSTD_isError(cResult) ? 0 : jobPtr->dstFlushed;
                 assert(flushed <= produced);
                 fps.ingested += jobPtr->src.size;
                 fps.consumed += jobPtr->consumed;
                 fps.produced += produced;
                 fps.flushed  += flushed;
                 fps.nbActiveWorkers += (jobPtr->consumed < jobPtr->src.size);
             }
             ZSTD_pthread_mutex_unlock(&mtctx->jobs[wJobID].job_mutex);
         }
     }
     return fps;
 }
 
 
 size_t ZSTDMT_toFlushNow(ZSTDMT_CCtx* mtctx)
 {
     size_t toFlush;
     unsigned const jobID = mtctx->doneJobID;
     assert(jobID <= mtctx->nextJobID);
     if (jobID == mtctx->nextJobID) return 0;   /* no active job => nothing to flush */
 
     /* look into oldest non-fully-flushed job */
     {   unsigned const wJobID = jobID & mtctx->jobIDMask;
         ZSTDMT_jobDescription* const jobPtr = &mtctx->jobs[wJobID];
         ZSTD_pthread_mutex_lock(&jobPtr->job_mutex);
         {   size_t const cResult = jobPtr->cSize;
             size_t const produced = ZSTD_isError(cResult) ? 0 : cResult;
             size_t const flushed = ZSTD_isError(cResult) ? 0 : jobPtr->dstFlushed;
             assert(flushed <= produced);
             assert(jobPtr->consumed <= jobPtr->src.size);
             toFlush = produced - flushed;
             /* if toFlush==0, nothing is available to flush.
              * However, jobID is expected to still be active:
              * if jobID was already completed and fully flushed,
              * ZSTDMT_flushProduced() should have already moved onto next job.
              * Therefore, some input has not yet been consumed. */
             if (toFlush==0) {
                 assert(jobPtr->consumed < jobPtr->src.size);
             }
         }
         ZSTD_pthread_mutex_unlock(&mtctx->jobs[wJobID].job_mutex);
     }
 
     return toFlush;
 }
 
 
 /* ------------------------------------------ */
 /* =====   Multi-threaded compression   ===== */
 /* ------------------------------------------ */
 
-static unsigned ZSTDMT_computeTargetJobLog(ZSTD_CCtx_params const params)
+static unsigned ZSTDMT_computeTargetJobLog(const ZSTD_CCtx_params* params)
 {
     unsigned jobLog;
-    if (params.ldmParams.enableLdm) {
+    if (params->ldmParams.enableLdm) {
         /* In Long Range Mode, the windowLog is typically oversized.
          * In which case, it's preferable to determine the jobSize
          * based on chainLog instead. */
-        jobLog = MAX(21, params.cParams.chainLog + 4);
+        jobLog = MAX(21, params->cParams.chainLog + 4);
     } else {
-        jobLog = MAX(20, params.cParams.windowLog + 2);
+        jobLog = MAX(20, params->cParams.windowLog + 2);
     }
     return MIN(jobLog, (unsigned)ZSTDMT_JOBLOG_MAX);
 }
 
 static int ZSTDMT_overlapLog_default(ZSTD_strategy strat)
 {
     switch(strat)
     {
         case ZSTD_btultra2:
             return 9;
         case ZSTD_btultra:
         case ZSTD_btopt:
             return 8;
         case ZSTD_btlazy2:
         case ZSTD_lazy2:
             return 7;
         case ZSTD_lazy:
         case ZSTD_greedy:
         case ZSTD_dfast:
         case ZSTD_fast:
         default:;
     }
     return 6;
 }
 
 static int ZSTDMT_overlapLog(int ovlog, ZSTD_strategy strat)
 {
     assert(0 <= ovlog && ovlog <= 9);
     if (ovlog == 0) return ZSTDMT_overlapLog_default(strat);
     return ovlog;
 }
 
-static size_t ZSTDMT_computeOverlapSize(ZSTD_CCtx_params const params)
+static size_t ZSTDMT_computeOverlapSize(const ZSTD_CCtx_params* params)
 {
-    int const overlapRLog = 9 - ZSTDMT_overlapLog(params.overlapLog, params.cParams.strategy);
-    int ovLog = (overlapRLog >= 8) ? 0 : (params.cParams.windowLog - overlapRLog);
+    int const overlapRLog = 9 - ZSTDMT_overlapLog(params->overlapLog, params->cParams.strategy);
+    int ovLog = (overlapRLog >= 8) ? 0 : (params->cParams.windowLog - overlapRLog);
     assert(0 <= overlapRLog && overlapRLog <= 8);
-    if (params.ldmParams.enableLdm) {
+    if (params->ldmParams.enableLdm) {
         /* In Long Range Mode, the windowLog is typically oversized.
          * In which case, it's preferable to determine the jobSize
          * based on chainLog instead.
          * Then, ovLog becomes a fraction of the jobSize, rather than windowSize */
-        ovLog = MIN(params.cParams.windowLog, ZSTDMT_computeTargetJobLog(params) - 2)
+        ovLog = MIN(params->cParams.windowLog, ZSTDMT_computeTargetJobLog(params) - 2)
                 - overlapRLog;
     }
     assert(0 <= ovLog && ovLog <= ZSTD_WINDOWLOG_MAX);
-    DEBUGLOG(4, "overlapLog : %i", params.overlapLog);
+    DEBUGLOG(4, "overlapLog : %i", params->overlapLog);
     DEBUGLOG(4, "overlap size : %i", 1 << ovLog);
     return (ovLog==0) ? 0 : (size_t)1 << ovLog;
 }
 
 static unsigned
-ZSTDMT_computeNbJobs(ZSTD_CCtx_params params, size_t srcSize, unsigned nbWorkers)
+ZSTDMT_computeNbJobs(const ZSTD_CCtx_params* params, size_t srcSize, unsigned nbWorkers)
 {
     assert(nbWorkers>0);
     {   size_t const jobSizeTarget = (size_t)1 << ZSTDMT_computeTargetJobLog(params);
         size_t const jobMaxSize = jobSizeTarget << 2;
         size_t const passSizeMax = jobMaxSize * nbWorkers;
         unsigned const multiplier = (unsigned)(srcSize / passSizeMax) + 1;
         unsigned const nbJobsLarge = multiplier * nbWorkers;
         unsigned const nbJobsMax = (unsigned)(srcSize / jobSizeTarget) + 1;
         unsigned const nbJobsSmall = MIN(nbJobsMax, nbWorkers);
         return (multiplier>1) ? nbJobsLarge : nbJobsSmall;
 }   }
 
 /* ZSTDMT_compress_advanced_internal() :
  * This is a blocking function : it will only give back control to caller after finishing its compression job.
  */
 static size_t ZSTDMT_compress_advanced_internal(
                 ZSTDMT_CCtx* mtctx,
                 void* dst, size_t dstCapacity,
           const void* src, size_t srcSize,
           const ZSTD_CDict* cdict,
                 ZSTD_CCtx_params params)
 {
-    ZSTD_CCtx_params const jobParams = ZSTDMT_initJobCCtxParams(params);
-    size_t const overlapSize = ZSTDMT_computeOverlapSize(params);
-    unsigned const nbJobs = ZSTDMT_computeNbJobs(params, srcSize, params.nbWorkers);
+    ZSTD_CCtx_params const jobParams = ZSTDMT_initJobCCtxParams(¶ms);
+    size_t const overlapSize = ZSTDMT_computeOverlapSize(¶ms);
+    unsigned const nbJobs = ZSTDMT_computeNbJobs(¶ms, srcSize, params.nbWorkers);
     size_t const proposedJobSize = (srcSize + (nbJobs-1)) / nbJobs;
     size_t const avgJobSize = (((proposedJobSize-1) & 0x1FFFF) < 0x7FFF) ? proposedJobSize + 0xFFFF : proposedJobSize;   /* avoid too small last block */
     const char* const srcStart = (const char*)src;
     size_t remainingSrcSize = srcSize;
     unsigned const compressWithinDst = (dstCapacity >= ZSTD_compressBound(srcSize)) ? nbJobs : (unsigned)(dstCapacity / ZSTD_compressBound(avgJobSize));  /* presumes avgJobSize >= 256 KB, which should be the case */
     size_t frameStartPos = 0, dstBufferPos = 0;
     assert(jobParams.nbWorkers == 0);
     assert(mtctx->cctxPool->totalCCtx == params.nbWorkers);
 
     params.jobSize = (U32)avgJobSize;
     DEBUGLOG(4, "ZSTDMT_compress_advanced_internal: nbJobs=%2u (rawSize=%u bytes; fixedSize=%u) ",
                 nbJobs, (U32)proposedJobSize, (U32)avgJobSize);
 
     if ((nbJobs==1) | (params.nbWorkers<=1)) {   /* fallback to single-thread mode : this is a blocking invocation anyway */
         ZSTD_CCtx* const cctx = mtctx->cctxPool->cctx[0];
         DEBUGLOG(4, "ZSTDMT_compress_advanced_internal: fallback to single-thread mode");
         if (cdict) return ZSTD_compress_usingCDict_advanced(cctx, dst, dstCapacity, src, srcSize, cdict, jobParams.fParams);
-        return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, NULL, 0, jobParams);
+        return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, NULL, 0, &jobParams);
     }
 
     assert(avgJobSize >= 256 KB);  /* condition for ZSTD_compressBound(A) + ZSTD_compressBound(B) <= ZSTD_compressBound(A+B), required to compress directly into Dst (no additional buffer) */
     ZSTDMT_setBufferSize(mtctx->bufPool, ZSTD_compressBound(avgJobSize) );
     if (ZSTDMT_serialState_reset(&mtctx->serial, mtctx->seqPool, params, avgJobSize))
         return ERROR(memory_allocation);
 
     FORWARD_IF_ERROR( ZSTDMT_expandJobsTable(mtctx, nbJobs) );  /* only expands if necessary */
 
     {   unsigned u;
         for (u=0; ujobs[u].prefix.start = srcStart + frameStartPos - dictSize;
             mtctx->jobs[u].prefix.size = dictSize;
             mtctx->jobs[u].src.start = srcStart + frameStartPos;
             mtctx->jobs[u].src.size = jobSize; assert(jobSize > 0);  /* avoid job.src.size == 0 */
             mtctx->jobs[u].consumed = 0;
             mtctx->jobs[u].cSize = 0;
             mtctx->jobs[u].cdict = (u==0) ? cdict : NULL;
             mtctx->jobs[u].fullFrameSize = srcSize;
             mtctx->jobs[u].params = jobParams;
             /* do not calculate checksum within sections, but write it in header for first section */
             mtctx->jobs[u].dstBuff = dstBuffer;
             mtctx->jobs[u].cctxPool = mtctx->cctxPool;
             mtctx->jobs[u].bufPool = mtctx->bufPool;
             mtctx->jobs[u].seqPool = mtctx->seqPool;
             mtctx->jobs[u].serial = &mtctx->serial;
             mtctx->jobs[u].jobID = u;
             mtctx->jobs[u].firstJob = (u==0);
             mtctx->jobs[u].lastJob = (u==nbJobs-1);
 
             DEBUGLOG(5, "ZSTDMT_compress_advanced_internal: posting job %u  (%u bytes)", u, (U32)jobSize);
             DEBUG_PRINTHEX(6, mtctx->jobs[u].prefix.start, 12);
             POOL_add(mtctx->factory, ZSTDMT_compressionJob, &mtctx->jobs[u]);
 
             frameStartPos += jobSize;
             dstBufferPos += dstBufferCapacity;
             remainingSrcSize -= jobSize;
     }   }
 
     /* collect result */
     {   size_t error = 0, dstPos = 0;
         unsigned jobID;
         for (jobID=0; jobIDjobs[jobID].job_mutex);
             while (mtctx->jobs[jobID].consumed < mtctx->jobs[jobID].src.size) {
                 DEBUGLOG(5, "waiting for jobCompleted signal from job %u", jobID);
                 ZSTD_pthread_cond_wait(&mtctx->jobs[jobID].job_cond, &mtctx->jobs[jobID].job_mutex);
             }
             ZSTD_pthread_mutex_unlock(&mtctx->jobs[jobID].job_mutex);
             DEBUGLOG(5, "ready to write job %u ", jobID);
 
             {   size_t const cSize = mtctx->jobs[jobID].cSize;
                 if (ZSTD_isError(cSize)) error = cSize;
                 if ((!error) && (dstPos + cSize > dstCapacity)) error = ERROR(dstSize_tooSmall);
                 if (jobID) {   /* note : job 0 is written directly at dst, which is correct position */
                     if (!error)
                         memmove((char*)dst + dstPos, mtctx->jobs[jobID].dstBuff.start, cSize);  /* may overlap when job compressed within dst */
                     if (jobID >= compressWithinDst) {  /* job compressed into its own buffer, which must be released */
                         DEBUGLOG(5, "releasing buffer %u>=%u", jobID, compressWithinDst);
                         ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[jobID].dstBuff);
                 }   }
                 mtctx->jobs[jobID].dstBuff = g_nullBuffer;
                 mtctx->jobs[jobID].cSize = 0;
                 dstPos += cSize ;
             }
         }  /* for (jobID=0; jobIDserial.xxhState);
             if (dstPos + 4 > dstCapacity) {
                 error = ERROR(dstSize_tooSmall);
             } else {
                 DEBUGLOG(4, "writing checksum : %08X \n", checksum);
                 MEM_writeLE32((char*)dst + dstPos, checksum);
                 dstPos += 4;
         }   }
 
         if (!error) DEBUGLOG(4, "compressed size : %u  ", (U32)dstPos);
         return error ? error : dstPos;
     }
 }
 
 size_t ZSTDMT_compress_advanced(ZSTDMT_CCtx* mtctx,
                                 void* dst, size_t dstCapacity,
                           const void* src, size_t srcSize,
                           const ZSTD_CDict* cdict,
                                 ZSTD_parameters params,
                                 int overlapLog)
 {
     ZSTD_CCtx_params cctxParams = mtctx->params;
     cctxParams.cParams = params.cParams;
     cctxParams.fParams = params.fParams;
     assert(ZSTD_OVERLAPLOG_MIN <= overlapLog && overlapLog <= ZSTD_OVERLAPLOG_MAX);
     cctxParams.overlapLog = overlapLog;
     return ZSTDMT_compress_advanced_internal(mtctx,
                                              dst, dstCapacity,
                                              src, srcSize,
                                              cdict, cctxParams);
 }
 
 
 size_t ZSTDMT_compressCCtx(ZSTDMT_CCtx* mtctx,
                            void* dst, size_t dstCapacity,
                      const void* src, size_t srcSize,
                            int compressionLevel)
 {
     ZSTD_parameters params = ZSTD_getParams(compressionLevel, srcSize, 0);
     int const overlapLog = ZSTDMT_overlapLog_default(params.cParams.strategy);
     params.fParams.contentSizeFlag = 1;
     return ZSTDMT_compress_advanced(mtctx, dst, dstCapacity, src, srcSize, NULL, params, overlapLog);
 }
 
 
 /* ====================================== */
 /* =======      Streaming API     ======= */
 /* ====================================== */
 
 size_t ZSTDMT_initCStream_internal(
         ZSTDMT_CCtx* mtctx,
         const void* dict, size_t dictSize, ZSTD_dictContentType_e dictContentType,
         const ZSTD_CDict* cdict, ZSTD_CCtx_params params,
         unsigned long long pledgedSrcSize)
 {
     DEBUGLOG(4, "ZSTDMT_initCStream_internal (pledgedSrcSize=%u, nbWorkers=%u, cctxPool=%u)",
                 (U32)pledgedSrcSize, params.nbWorkers, mtctx->cctxPool->totalCCtx);
 
     /* params supposed partially fully validated at this point */
     assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
     assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
 
     /* init */
     if (params.nbWorkers != mtctx->params.nbWorkers)
         FORWARD_IF_ERROR( ZSTDMT_resize(mtctx, params.nbWorkers) );
 
     if (params.jobSize != 0 && params.jobSize < ZSTDMT_JOBSIZE_MIN) params.jobSize = ZSTDMT_JOBSIZE_MIN;
     if (params.jobSize > (size_t)ZSTDMT_JOBSIZE_MAX) params.jobSize = (size_t)ZSTDMT_JOBSIZE_MAX;
 
     mtctx->singleBlockingThread = (pledgedSrcSize <= ZSTDMT_JOBSIZE_MIN);  /* do not trigger multi-threading when srcSize is too small */
     if (mtctx->singleBlockingThread) {
-        ZSTD_CCtx_params const singleThreadParams = ZSTDMT_initJobCCtxParams(params);
+        ZSTD_CCtx_params const singleThreadParams = ZSTDMT_initJobCCtxParams(¶ms);
         DEBUGLOG(5, "ZSTDMT_initCStream_internal: switch to single blocking thread mode");
         assert(singleThreadParams.nbWorkers == 0);
         return ZSTD_initCStream_internal(mtctx->cctxPool->cctx[0],
                                          dict, dictSize, cdict,
-                                         singleThreadParams, pledgedSrcSize);
+                                         &singleThreadParams, pledgedSrcSize);
     }
 
     DEBUGLOG(4, "ZSTDMT_initCStream_internal: %u workers", params.nbWorkers);
 
     if (mtctx->allJobsCompleted == 0) {   /* previous compression not correctly finished */
         ZSTDMT_waitForAllJobsCompleted(mtctx);
         ZSTDMT_releaseAllJobResources(mtctx);
         mtctx->allJobsCompleted = 1;
     }
 
     mtctx->params = params;
     mtctx->frameContentSize = pledgedSrcSize;
     if (dict) {
         ZSTD_freeCDict(mtctx->cdictLocal);
         mtctx->cdictLocal = ZSTD_createCDict_advanced(dict, dictSize,
                                                     ZSTD_dlm_byCopy, dictContentType, /* note : a loadPrefix becomes an internal CDict */
                                                     params.cParams, mtctx->cMem);
         mtctx->cdict = mtctx->cdictLocal;
         if (mtctx->cdictLocal == NULL) return ERROR(memory_allocation);
     } else {
         ZSTD_freeCDict(mtctx->cdictLocal);
         mtctx->cdictLocal = NULL;
         mtctx->cdict = cdict;
     }
 
-    mtctx->targetPrefixSize = ZSTDMT_computeOverlapSize(params);
+    mtctx->targetPrefixSize = ZSTDMT_computeOverlapSize(¶ms);
     DEBUGLOG(4, "overlapLog=%i => %u KB", params.overlapLog, (U32)(mtctx->targetPrefixSize>>10));
     mtctx->targetSectionSize = params.jobSize;
     if (mtctx->targetSectionSize == 0) {
-        mtctx->targetSectionSize = 1ULL << ZSTDMT_computeTargetJobLog(params);
+        mtctx->targetSectionSize = 1ULL << ZSTDMT_computeTargetJobLog(¶ms);
     }
     assert(mtctx->targetSectionSize <= (size_t)ZSTDMT_JOBSIZE_MAX);
 
     if (params.rsyncable) {
         /* Aim for the targetsectionSize as the average job size. */
         U32 const jobSizeMB = (U32)(mtctx->targetSectionSize >> 20);
         U32 const rsyncBits = ZSTD_highbit32(jobSizeMB) + 20;
         assert(jobSizeMB >= 1);
         DEBUGLOG(4, "rsyncLog = %u", rsyncBits);
         mtctx->rsync.hash = 0;
         mtctx->rsync.hitMask = (1ULL << rsyncBits) - 1;
         mtctx->rsync.primePower = ZSTD_rollingHash_primePower(RSYNC_LENGTH);
     }
     if (mtctx->targetSectionSize < mtctx->targetPrefixSize) mtctx->targetSectionSize = mtctx->targetPrefixSize;  /* job size must be >= overlap size */
     DEBUGLOG(4, "Job Size : %u KB (note : set to %u)", (U32)(mtctx->targetSectionSize>>10), (U32)params.jobSize);
     DEBUGLOG(4, "inBuff Size : %u KB", (U32)(mtctx->targetSectionSize>>10));
     ZSTDMT_setBufferSize(mtctx->bufPool, ZSTD_compressBound(mtctx->targetSectionSize));
     {
         /* If ldm is enabled we need windowSize space. */
         size_t const windowSize = mtctx->params.ldmParams.enableLdm ? (1U << mtctx->params.cParams.windowLog) : 0;
         /* Two buffers of slack, plus extra space for the overlap
          * This is the minimum slack that LDM works with. One extra because
          * flush might waste up to targetSectionSize-1 bytes. Another extra
          * for the overlap (if > 0), then one to fill which doesn't overlap
          * with the LDM window.
          */
         size_t const nbSlackBuffers = 2 + (mtctx->targetPrefixSize > 0);
         size_t const slackSize = mtctx->targetSectionSize * nbSlackBuffers;
         /* Compute the total size, and always have enough slack */
         size_t const nbWorkers = MAX(mtctx->params.nbWorkers, 1);
         size_t const sectionsSize = mtctx->targetSectionSize * nbWorkers;
         size_t const capacity = MAX(windowSize, sectionsSize) + slackSize;
         if (mtctx->roundBuff.capacity < capacity) {
             if (mtctx->roundBuff.buffer)
                 ZSTD_free(mtctx->roundBuff.buffer, mtctx->cMem);
             mtctx->roundBuff.buffer = (BYTE*)ZSTD_malloc(capacity, mtctx->cMem);
             if (mtctx->roundBuff.buffer == NULL) {
                 mtctx->roundBuff.capacity = 0;
                 return ERROR(memory_allocation);
             }
             mtctx->roundBuff.capacity = capacity;
         }
     }
     DEBUGLOG(4, "roundBuff capacity : %u KB", (U32)(mtctx->roundBuff.capacity>>10));
     mtctx->roundBuff.pos = 0;
     mtctx->inBuff.buffer = g_nullBuffer;
     mtctx->inBuff.filled = 0;
     mtctx->inBuff.prefix = kNullRange;
     mtctx->doneJobID = 0;
     mtctx->nextJobID = 0;
     mtctx->frameEnded = 0;
     mtctx->allJobsCompleted = 0;
     mtctx->consumed = 0;
     mtctx->produced = 0;
     if (ZSTDMT_serialState_reset(&mtctx->serial, mtctx->seqPool, params, mtctx->targetSectionSize))
         return ERROR(memory_allocation);
     return 0;
 }
 
 size_t ZSTDMT_initCStream_advanced(ZSTDMT_CCtx* mtctx,
                              const void* dict, size_t dictSize,
                                    ZSTD_parameters params,
                                    unsigned long long pledgedSrcSize)
 {
     ZSTD_CCtx_params cctxParams = mtctx->params;  /* retrieve sticky params */
     DEBUGLOG(4, "ZSTDMT_initCStream_advanced (pledgedSrcSize=%u)", (U32)pledgedSrcSize);
     cctxParams.cParams = params.cParams;
     cctxParams.fParams = params.fParams;
     return ZSTDMT_initCStream_internal(mtctx, dict, dictSize, ZSTD_dct_auto, NULL,
                                        cctxParams, pledgedSrcSize);
 }
 
 size_t ZSTDMT_initCStream_usingCDict(ZSTDMT_CCtx* mtctx,
                                const ZSTD_CDict* cdict,
                                      ZSTD_frameParameters fParams,
                                      unsigned long long pledgedSrcSize)
 {
     ZSTD_CCtx_params cctxParams = mtctx->params;
     if (cdict==NULL) return ERROR(dictionary_wrong);   /* method incompatible with NULL cdict */
     cctxParams.cParams = ZSTD_getCParamsFromCDict(cdict);
     cctxParams.fParams = fParams;
     return ZSTDMT_initCStream_internal(mtctx, NULL, 0 /*dictSize*/, ZSTD_dct_auto, cdict,
                                        cctxParams, pledgedSrcSize);
 }
 
 
 /* ZSTDMT_resetCStream() :
  * pledgedSrcSize can be zero == unknown (for the time being)
  * prefer using ZSTD_CONTENTSIZE_UNKNOWN,
  * as `0` might mean "empty" in the future */
 size_t ZSTDMT_resetCStream(ZSTDMT_CCtx* mtctx, unsigned long long pledgedSrcSize)
 {
     if (!pledgedSrcSize) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;
     return ZSTDMT_initCStream_internal(mtctx, NULL, 0, ZSTD_dct_auto, 0, mtctx->params,
                                        pledgedSrcSize);
 }
 
 size_t ZSTDMT_initCStream(ZSTDMT_CCtx* mtctx, int compressionLevel) {
     ZSTD_parameters const params = ZSTD_getParams(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, 0);
     ZSTD_CCtx_params cctxParams = mtctx->params;   /* retrieve sticky params */
     DEBUGLOG(4, "ZSTDMT_initCStream (cLevel=%i)", compressionLevel);
     cctxParams.cParams = params.cParams;
     cctxParams.fParams = params.fParams;
     return ZSTDMT_initCStream_internal(mtctx, NULL, 0, ZSTD_dct_auto, NULL, cctxParams, ZSTD_CONTENTSIZE_UNKNOWN);
 }
 
 
 /* ZSTDMT_writeLastEmptyBlock()
  * Write a single empty block with an end-of-frame to finish a frame.
  * Job must be created from streaming variant.
  * This function is always successful if expected conditions are fulfilled.
  */
 static void ZSTDMT_writeLastEmptyBlock(ZSTDMT_jobDescription* job)
 {
     assert(job->lastJob == 1);
     assert(job->src.size == 0);   /* last job is empty -> will be simplified into a last empty block */
     assert(job->firstJob == 0);   /* cannot be first job, as it also needs to create frame header */
     assert(job->dstBuff.start == NULL);   /* invoked from streaming variant only (otherwise, dstBuff might be user's output) */
     job->dstBuff = ZSTDMT_getBuffer(job->bufPool);
     if (job->dstBuff.start == NULL) {
       job->cSize = ERROR(memory_allocation);
       return;
     }
     assert(job->dstBuff.capacity >= ZSTD_blockHeaderSize);   /* no buffer should ever be that small */
     job->src = kNullRange;
     job->cSize = ZSTD_writeLastEmptyBlock(job->dstBuff.start, job->dstBuff.capacity);
     assert(!ZSTD_isError(job->cSize));
     assert(job->consumed == 0);
 }
 
 static size_t ZSTDMT_createCompressionJob(ZSTDMT_CCtx* mtctx, size_t srcSize, ZSTD_EndDirective endOp)
 {
     unsigned const jobID = mtctx->nextJobID & mtctx->jobIDMask;
     int const endFrame = (endOp == ZSTD_e_end);
 
     if (mtctx->nextJobID > mtctx->doneJobID + mtctx->jobIDMask) {
         DEBUGLOG(5, "ZSTDMT_createCompressionJob: will not create new job : table is full");
         assert((mtctx->nextJobID & mtctx->jobIDMask) == (mtctx->doneJobID & mtctx->jobIDMask));
         return 0;
     }
 
     if (!mtctx->jobReady) {
         BYTE const* src = (BYTE const*)mtctx->inBuff.buffer.start;
         DEBUGLOG(5, "ZSTDMT_createCompressionJob: preparing job %u to compress %u bytes with %u preload ",
                     mtctx->nextJobID, (U32)srcSize, (U32)mtctx->inBuff.prefix.size);
         mtctx->jobs[jobID].src.start = src;
         mtctx->jobs[jobID].src.size = srcSize;
         assert(mtctx->inBuff.filled >= srcSize);
         mtctx->jobs[jobID].prefix = mtctx->inBuff.prefix;
         mtctx->jobs[jobID].consumed = 0;
         mtctx->jobs[jobID].cSize = 0;
         mtctx->jobs[jobID].params = mtctx->params;
         mtctx->jobs[jobID].cdict = mtctx->nextJobID==0 ? mtctx->cdict : NULL;
         mtctx->jobs[jobID].fullFrameSize = mtctx->frameContentSize;
         mtctx->jobs[jobID].dstBuff = g_nullBuffer;
         mtctx->jobs[jobID].cctxPool = mtctx->cctxPool;
         mtctx->jobs[jobID].bufPool = mtctx->bufPool;
         mtctx->jobs[jobID].seqPool = mtctx->seqPool;
         mtctx->jobs[jobID].serial = &mtctx->serial;
         mtctx->jobs[jobID].jobID = mtctx->nextJobID;
         mtctx->jobs[jobID].firstJob = (mtctx->nextJobID==0);
         mtctx->jobs[jobID].lastJob = endFrame;
         mtctx->jobs[jobID].frameChecksumNeeded = mtctx->params.fParams.checksumFlag && endFrame && (mtctx->nextJobID>0);
         mtctx->jobs[jobID].dstFlushed = 0;
 
         /* Update the round buffer pos and clear the input buffer to be reset */
         mtctx->roundBuff.pos += srcSize;
         mtctx->inBuff.buffer = g_nullBuffer;
         mtctx->inBuff.filled = 0;
         /* Set the prefix */
         if (!endFrame) {
             size_t const newPrefixSize = MIN(srcSize, mtctx->targetPrefixSize);
             mtctx->inBuff.prefix.start = src + srcSize - newPrefixSize;
             mtctx->inBuff.prefix.size = newPrefixSize;
         } else {   /* endFrame==1 => no need for another input buffer */
             mtctx->inBuff.prefix = kNullRange;
             mtctx->frameEnded = endFrame;
             if (mtctx->nextJobID == 0) {
                 /* single job exception : checksum is already calculated directly within worker thread */
                 mtctx->params.fParams.checksumFlag = 0;
         }   }
 
         if ( (srcSize == 0)
           && (mtctx->nextJobID>0)/*single job must also write frame header*/ ) {
             DEBUGLOG(5, "ZSTDMT_createCompressionJob: creating a last empty block to end frame");
             assert(endOp == ZSTD_e_end);  /* only possible case : need to end the frame with an empty last block */
             ZSTDMT_writeLastEmptyBlock(mtctx->jobs + jobID);
             mtctx->nextJobID++;
             return 0;
         }
     }
 
     DEBUGLOG(5, "ZSTDMT_createCompressionJob: posting job %u : %u bytes  (end:%u, jobNb == %u (mod:%u))",
                 mtctx->nextJobID,
                 (U32)mtctx->jobs[jobID].src.size,
                 mtctx->jobs[jobID].lastJob,
                 mtctx->nextJobID,
                 jobID);
     if (POOL_tryAdd(mtctx->factory, ZSTDMT_compressionJob, &mtctx->jobs[jobID])) {
         mtctx->nextJobID++;
         mtctx->jobReady = 0;
     } else {
         DEBUGLOG(5, "ZSTDMT_createCompressionJob: no worker available for job %u", mtctx->nextJobID);
         mtctx->jobReady = 1;
     }
     return 0;
 }
 
 
 /*! ZSTDMT_flushProduced() :
  *  flush whatever data has been produced but not yet flushed in current job.
  *  move to next job if current one is fully flushed.
  * `output` : `pos` will be updated with amount of data flushed .
  * `blockToFlush` : if >0, the function will block and wait if there is no data available to flush .
  * @return : amount of data remaining within internal buffer, 0 if no more, 1 if unknown but > 0, or an error code */
 static size_t ZSTDMT_flushProduced(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output, unsigned blockToFlush, ZSTD_EndDirective end)
 {
     unsigned const wJobID = mtctx->doneJobID & mtctx->jobIDMask;
     DEBUGLOG(5, "ZSTDMT_flushProduced (blocking:%u , job %u <= %u)",
                 blockToFlush, mtctx->doneJobID, mtctx->nextJobID);
     assert(output->size >= output->pos);
 
     ZSTD_PTHREAD_MUTEX_LOCK(&mtctx->jobs[wJobID].job_mutex);
     if (  blockToFlush
       && (mtctx->doneJobID < mtctx->nextJobID) ) {
         assert(mtctx->jobs[wJobID].dstFlushed <= mtctx->jobs[wJobID].cSize);
         while (mtctx->jobs[wJobID].dstFlushed == mtctx->jobs[wJobID].cSize) {  /* nothing to flush */
             if (mtctx->jobs[wJobID].consumed == mtctx->jobs[wJobID].src.size) {
                 DEBUGLOG(5, "job %u is completely consumed (%u == %u) => don't wait for cond, there will be none",
                             mtctx->doneJobID, (U32)mtctx->jobs[wJobID].consumed, (U32)mtctx->jobs[wJobID].src.size);
                 break;
             }
             DEBUGLOG(5, "waiting for something to flush from job %u (currently flushed: %u bytes)",
                         mtctx->doneJobID, (U32)mtctx->jobs[wJobID].dstFlushed);
             ZSTD_pthread_cond_wait(&mtctx->jobs[wJobID].job_cond, &mtctx->jobs[wJobID].job_mutex);  /* block when nothing to flush but some to come */
     }   }
 
     /* try to flush something */
     {   size_t cSize = mtctx->jobs[wJobID].cSize;                  /* shared */
         size_t const srcConsumed = mtctx->jobs[wJobID].consumed;   /* shared */
         size_t const srcSize = mtctx->jobs[wJobID].src.size;       /* read-only, could be done after mutex lock, but no-declaration-after-statement */
         ZSTD_pthread_mutex_unlock(&mtctx->jobs[wJobID].job_mutex);
         if (ZSTD_isError(cSize)) {
             DEBUGLOG(5, "ZSTDMT_flushProduced: job %u : compression error detected : %s",
                         mtctx->doneJobID, ZSTD_getErrorName(cSize));
             ZSTDMT_waitForAllJobsCompleted(mtctx);
             ZSTDMT_releaseAllJobResources(mtctx);
             return cSize;
         }
         /* add frame checksum if necessary (can only happen once) */
         assert(srcConsumed <= srcSize);
         if ( (srcConsumed == srcSize)   /* job completed -> worker no longer active */
           && mtctx->jobs[wJobID].frameChecksumNeeded ) {
             U32 const checksum = (U32)XXH64_digest(&mtctx->serial.xxhState);
             DEBUGLOG(4, "ZSTDMT_flushProduced: writing checksum : %08X \n", checksum);
             MEM_writeLE32((char*)mtctx->jobs[wJobID].dstBuff.start + mtctx->jobs[wJobID].cSize, checksum);
             cSize += 4;
             mtctx->jobs[wJobID].cSize += 4;  /* can write this shared value, as worker is no longer active */
             mtctx->jobs[wJobID].frameChecksumNeeded = 0;
         }
 
         if (cSize > 0) {   /* compression is ongoing or completed */
             size_t const toFlush = MIN(cSize - mtctx->jobs[wJobID].dstFlushed, output->size - output->pos);
             DEBUGLOG(5, "ZSTDMT_flushProduced: Flushing %u bytes from job %u (completion:%u/%u, generated:%u)",
                         (U32)toFlush, mtctx->doneJobID, (U32)srcConsumed, (U32)srcSize, (U32)cSize);
             assert(mtctx->doneJobID < mtctx->nextJobID);
             assert(cSize >= mtctx->jobs[wJobID].dstFlushed);
             assert(mtctx->jobs[wJobID].dstBuff.start != NULL);
             memcpy((char*)output->dst + output->pos,
                    (const char*)mtctx->jobs[wJobID].dstBuff.start + mtctx->jobs[wJobID].dstFlushed,
                    toFlush);
             output->pos += toFlush;
             mtctx->jobs[wJobID].dstFlushed += toFlush;  /* can write : this value is only used by mtctx */
 
             if ( (srcConsumed == srcSize)    /* job is completed */
               && (mtctx->jobs[wJobID].dstFlushed == cSize) ) {   /* output buffer fully flushed => free this job position */
                 DEBUGLOG(5, "Job %u completed (%u bytes), moving to next one",
                         mtctx->doneJobID, (U32)mtctx->jobs[wJobID].dstFlushed);
                 ZSTDMT_releaseBuffer(mtctx->bufPool, mtctx->jobs[wJobID].dstBuff);
                 DEBUGLOG(5, "dstBuffer released");
                 mtctx->jobs[wJobID].dstBuff = g_nullBuffer;
                 mtctx->jobs[wJobID].cSize = 0;   /* ensure this job slot is considered "not started" in future check */
                 mtctx->consumed += srcSize;
                 mtctx->produced += cSize;
                 mtctx->doneJobID++;
         }   }
 
         /* return value : how many bytes left in buffer ; fake it to 1 when unknown but >0 */
         if (cSize > mtctx->jobs[wJobID].dstFlushed) return (cSize - mtctx->jobs[wJobID].dstFlushed);
         if (srcSize > srcConsumed) return 1;   /* current job not completely compressed */
     }
     if (mtctx->doneJobID < mtctx->nextJobID) return 1;   /* some more jobs ongoing */
     if (mtctx->jobReady) return 1;      /* one job is ready to push, just not yet in the list */
     if (mtctx->inBuff.filled > 0) return 1;   /* input is not empty, and still needs to be converted into a job */
     mtctx->allJobsCompleted = mtctx->frameEnded;   /* all jobs are entirely flushed => if this one is last one, frame is completed */
     if (end == ZSTD_e_end) return !mtctx->frameEnded;  /* for ZSTD_e_end, question becomes : is frame completed ? instead of : are internal buffers fully flushed ? */
     return 0;   /* internal buffers fully flushed */
 }
 
 /**
  * Returns the range of data used by the earliest job that is not yet complete.
  * If the data of the first job is broken up into two segments, we cover both
  * sections.
  */
 static range_t ZSTDMT_getInputDataInUse(ZSTDMT_CCtx* mtctx)
 {
     unsigned const firstJobID = mtctx->doneJobID;
     unsigned const lastJobID = mtctx->nextJobID;
     unsigned jobID;
 
     for (jobID = firstJobID; jobID < lastJobID; ++jobID) {
         unsigned const wJobID = jobID & mtctx->jobIDMask;
         size_t consumed;
 
         ZSTD_PTHREAD_MUTEX_LOCK(&mtctx->jobs[wJobID].job_mutex);
         consumed = mtctx->jobs[wJobID].consumed;
         ZSTD_pthread_mutex_unlock(&mtctx->jobs[wJobID].job_mutex);
 
         if (consumed < mtctx->jobs[wJobID].src.size) {
             range_t range = mtctx->jobs[wJobID].prefix;
             if (range.size == 0) {
                 /* Empty prefix */
                 range = mtctx->jobs[wJobID].src;
             }
             /* Job source in multiple segments not supported yet */
             assert(range.start <= mtctx->jobs[wJobID].src.start);
             return range;
         }
     }
     return kNullRange;
 }
 
 /**
  * Returns non-zero iff buffer and range overlap.
  */
 static int ZSTDMT_isOverlapped(buffer_t buffer, range_t range)
 {
     BYTE const* const bufferStart = (BYTE const*)buffer.start;
     BYTE const* const bufferEnd = bufferStart + buffer.capacity;
     BYTE const* const rangeStart = (BYTE const*)range.start;
     BYTE const* const rangeEnd = rangeStart + range.size;
 
     if (rangeStart == NULL || bufferStart == NULL)
         return 0;
     /* Empty ranges cannot overlap */
     if (bufferStart == bufferEnd || rangeStart == rangeEnd)
         return 0;
 
     return bufferStart < rangeEnd && rangeStart < bufferEnd;
 }
 
 static int ZSTDMT_doesOverlapWindow(buffer_t buffer, ZSTD_window_t window)
 {
     range_t extDict;
     range_t prefix;
 
     DEBUGLOG(5, "ZSTDMT_doesOverlapWindow");
     extDict.start = window.dictBase + window.lowLimit;
     extDict.size = window.dictLimit - window.lowLimit;
 
     prefix.start = window.base + window.dictLimit;
     prefix.size = window.nextSrc - (window.base + window.dictLimit);
     DEBUGLOG(5, "extDict [0x%zx, 0x%zx)",
                 (size_t)extDict.start,
                 (size_t)extDict.start + extDict.size);
     DEBUGLOG(5, "prefix  [0x%zx, 0x%zx)",
                 (size_t)prefix.start,
                 (size_t)prefix.start + prefix.size);
 
     return ZSTDMT_isOverlapped(buffer, extDict)
         || ZSTDMT_isOverlapped(buffer, prefix);
 }
 
 static void ZSTDMT_waitForLdmComplete(ZSTDMT_CCtx* mtctx, buffer_t buffer)
 {
     if (mtctx->params.ldmParams.enableLdm) {
         ZSTD_pthread_mutex_t* mutex = &mtctx->serial.ldmWindowMutex;
         DEBUGLOG(5, "ZSTDMT_waitForLdmComplete");
         DEBUGLOG(5, "source  [0x%zx, 0x%zx)",
                     (size_t)buffer.start,
                     (size_t)buffer.start + buffer.capacity);
         ZSTD_PTHREAD_MUTEX_LOCK(mutex);
         while (ZSTDMT_doesOverlapWindow(buffer, mtctx->serial.ldmWindow)) {
             DEBUGLOG(5, "Waiting for LDM to finish...");
             ZSTD_pthread_cond_wait(&mtctx->serial.ldmWindowCond, mutex);
         }
         DEBUGLOG(6, "Done waiting for LDM to finish");
         ZSTD_pthread_mutex_unlock(mutex);
     }
 }
 
 /**
  * Attempts to set the inBuff to the next section to fill.
  * If any part of the new section is still in use we give up.
  * Returns non-zero if the buffer is filled.
  */
 static int ZSTDMT_tryGetInputRange(ZSTDMT_CCtx* mtctx)
 {
     range_t const inUse = ZSTDMT_getInputDataInUse(mtctx);
     size_t const spaceLeft = mtctx->roundBuff.capacity - mtctx->roundBuff.pos;
     size_t const target = mtctx->targetSectionSize;
     buffer_t buffer;
 
     DEBUGLOG(5, "ZSTDMT_tryGetInputRange");
     assert(mtctx->inBuff.buffer.start == NULL);
     assert(mtctx->roundBuff.capacity >= target);
 
     if (spaceLeft < target) {
         /* ZSTD_invalidateRepCodes() doesn't work for extDict variants.
          * Simply copy the prefix to the beginning in that case.
          */
         BYTE* const start = (BYTE*)mtctx->roundBuff.buffer;
         size_t const prefixSize = mtctx->inBuff.prefix.size;
 
         buffer.start = start;
         buffer.capacity = prefixSize;
         if (ZSTDMT_isOverlapped(buffer, inUse)) {
             DEBUGLOG(5, "Waiting for buffer...");
             return 0;
         }
         ZSTDMT_waitForLdmComplete(mtctx, buffer);
         memmove(start, mtctx->inBuff.prefix.start, prefixSize);
         mtctx->inBuff.prefix.start = start;
         mtctx->roundBuff.pos = prefixSize;
     }
     buffer.start = mtctx->roundBuff.buffer + mtctx->roundBuff.pos;
     buffer.capacity = target;
 
     if (ZSTDMT_isOverlapped(buffer, inUse)) {
         DEBUGLOG(5, "Waiting for buffer...");
         return 0;
     }
     assert(!ZSTDMT_isOverlapped(buffer, mtctx->inBuff.prefix));
 
     ZSTDMT_waitForLdmComplete(mtctx, buffer);
 
     DEBUGLOG(5, "Using prefix range [%zx, %zx)",
                 (size_t)mtctx->inBuff.prefix.start,
                 (size_t)mtctx->inBuff.prefix.start + mtctx->inBuff.prefix.size);
     DEBUGLOG(5, "Using source range [%zx, %zx)",
                 (size_t)buffer.start,
                 (size_t)buffer.start + buffer.capacity);
 
 
     mtctx->inBuff.buffer = buffer;
     mtctx->inBuff.filled = 0;
     assert(mtctx->roundBuff.pos + buffer.capacity <= mtctx->roundBuff.capacity);
     return 1;
 }
 
 typedef struct {
   size_t toLoad;  /* The number of bytes to load from the input. */
   int flush;      /* Boolean declaring if we must flush because we found a synchronization point. */
 } syncPoint_t;
 
 /**
  * Searches through the input for a synchronization point. If one is found, we
  * will instruct the caller to flush, and return the number of bytes to load.
  * Otherwise, we will load as many bytes as possible and instruct the caller
  * to continue as normal.
  */
 static syncPoint_t
 findSynchronizationPoint(ZSTDMT_CCtx const* mtctx, ZSTD_inBuffer const input)
 {
     BYTE const* const istart = (BYTE const*)input.src + input.pos;
     U64 const primePower = mtctx->rsync.primePower;
     U64 const hitMask = mtctx->rsync.hitMask;
 
     syncPoint_t syncPoint;
     U64 hash;
     BYTE const* prev;
     size_t pos;
 
     syncPoint.toLoad = MIN(input.size - input.pos, mtctx->targetSectionSize - mtctx->inBuff.filled);
     syncPoint.flush = 0;
     if (!mtctx->params.rsyncable)
         /* Rsync is disabled. */
         return syncPoint;
     if (mtctx->inBuff.filled + syncPoint.toLoad < RSYNC_LENGTH)
         /* Not enough to compute the hash.
          * We will miss any synchronization points in this RSYNC_LENGTH byte
          * window. However, since it depends only in the internal buffers, if the
          * state is already synchronized, we will remain synchronized.
          * Additionally, the probability that we miss a synchronization point is
          * low: RSYNC_LENGTH / targetSectionSize.
          */
         return syncPoint;
     /* Initialize the loop variables. */
     if (mtctx->inBuff.filled >= RSYNC_LENGTH) {
         /* We have enough bytes buffered to initialize the hash.
          * Start scanning at the beginning of the input.
          */
         pos = 0;
         prev = (BYTE const*)mtctx->inBuff.buffer.start + mtctx->inBuff.filled - RSYNC_LENGTH;
         hash = ZSTD_rollingHash_compute(prev, RSYNC_LENGTH);
     } else {
         /* We don't have enough bytes buffered to initialize the hash, but
          * we know we have at least RSYNC_LENGTH bytes total.
          * Start scanning after the first RSYNC_LENGTH bytes less the bytes
          * already buffered.
          */
         pos = RSYNC_LENGTH - mtctx->inBuff.filled;
         prev = (BYTE const*)mtctx->inBuff.buffer.start - pos;
         hash = ZSTD_rollingHash_compute(mtctx->inBuff.buffer.start, mtctx->inBuff.filled);
         hash = ZSTD_rollingHash_append(hash, istart, pos);
     }
     /* Starting with the hash of the previous RSYNC_LENGTH bytes, roll
      * through the input. If we hit a synchronization point, then cut the
      * job off, and tell the compressor to flush the job. Otherwise, load
      * all the bytes and continue as normal.
      * If we go too long without a synchronization point (targetSectionSize)
      * then a block will be emitted anyways, but this is okay, since if we
      * are already synchronized we will remain synchronized.
      */
     for (; pos < syncPoint.toLoad; ++pos) {
         BYTE const toRemove = pos < RSYNC_LENGTH ? prev[pos] : istart[pos - RSYNC_LENGTH];
         /* if (pos >= RSYNC_LENGTH) assert(ZSTD_rollingHash_compute(istart + pos - RSYNC_LENGTH, RSYNC_LENGTH) == hash); */
         hash = ZSTD_rollingHash_rotate(hash, toRemove, istart[pos], primePower);
         if ((hash & hitMask) == hitMask) {
             syncPoint.toLoad = pos + 1;
             syncPoint.flush = 1;
             break;
         }
     }
     return syncPoint;
 }
 
 size_t ZSTDMT_nextInputSizeHint(const ZSTDMT_CCtx* mtctx)
 {
     size_t hintInSize = mtctx->targetSectionSize - mtctx->inBuff.filled;
     if (hintInSize==0) hintInSize = mtctx->targetSectionSize;
     return hintInSize;
 }
 
 /** ZSTDMT_compressStream_generic() :
  *  internal use only - exposed to be invoked from zstd_compress.c
  *  assumption : output and input are valid (pos <= size)
  * @return : minimum amount of data remaining to flush, 0 if none */
 size_t ZSTDMT_compressStream_generic(ZSTDMT_CCtx* mtctx,
                                      ZSTD_outBuffer* output,
                                      ZSTD_inBuffer* input,
                                      ZSTD_EndDirective endOp)
 {
     unsigned forwardInputProgress = 0;
     DEBUGLOG(5, "ZSTDMT_compressStream_generic (endOp=%u, srcSize=%u)",
                 (U32)endOp, (U32)(input->size - input->pos));
     assert(output->pos <= output->size);
     assert(input->pos  <= input->size);
 
     if (mtctx->singleBlockingThread) {  /* delegate to single-thread (synchronous) */
         return ZSTD_compressStream2(mtctx->cctxPool->cctx[0], output, input, endOp);
     }
 
     if ((mtctx->frameEnded) && (endOp==ZSTD_e_continue)) {
         /* current frame being ended. Only flush/end are allowed */
         return ERROR(stage_wrong);
     }
 
     /* single-pass shortcut (note : synchronous-mode) */
     if ( (!mtctx->params.rsyncable)   /* rsyncable mode is disabled */
       && (mtctx->nextJobID == 0)      /* just started */
       && (mtctx->inBuff.filled == 0)  /* nothing buffered */
       && (!mtctx->jobReady)           /* no job already created */
       && (endOp == ZSTD_e_end)        /* end order */
       && (output->size - output->pos >= ZSTD_compressBound(input->size - input->pos)) ) { /* enough space in dst */
         size_t const cSize = ZSTDMT_compress_advanced_internal(mtctx,
                 (char*)output->dst + output->pos, output->size - output->pos,
                 (const char*)input->src + input->pos, input->size - input->pos,
                 mtctx->cdict, mtctx->params);
         if (ZSTD_isError(cSize)) return cSize;
         input->pos = input->size;
         output->pos += cSize;
         mtctx->allJobsCompleted = 1;
         mtctx->frameEnded = 1;
         return 0;
     }
 
     /* fill input buffer */
     if ( (!mtctx->jobReady)
       && (input->size > input->pos) ) {   /* support NULL input */
         if (mtctx->inBuff.buffer.start == NULL) {
             assert(mtctx->inBuff.filled == 0); /* Can't fill an empty buffer */
             if (!ZSTDMT_tryGetInputRange(mtctx)) {
                 /* It is only possible for this operation to fail if there are
                  * still compression jobs ongoing.
                  */
                 DEBUGLOG(5, "ZSTDMT_tryGetInputRange failed");
                 assert(mtctx->doneJobID != mtctx->nextJobID);
             } else
                 DEBUGLOG(5, "ZSTDMT_tryGetInputRange completed successfully : mtctx->inBuff.buffer.start = %p", mtctx->inBuff.buffer.start);
         }
         if (mtctx->inBuff.buffer.start != NULL) {
             syncPoint_t const syncPoint = findSynchronizationPoint(mtctx, *input);
             if (syncPoint.flush && endOp == ZSTD_e_continue) {
                 endOp = ZSTD_e_flush;
             }
             assert(mtctx->inBuff.buffer.capacity >= mtctx->targetSectionSize);
             DEBUGLOG(5, "ZSTDMT_compressStream_generic: adding %u bytes on top of %u to buffer of size %u",
                         (U32)syncPoint.toLoad, (U32)mtctx->inBuff.filled, (U32)mtctx->targetSectionSize);
             memcpy((char*)mtctx->inBuff.buffer.start + mtctx->inBuff.filled, (const char*)input->src + input->pos, syncPoint.toLoad);
             input->pos += syncPoint.toLoad;
             mtctx->inBuff.filled += syncPoint.toLoad;
             forwardInputProgress = syncPoint.toLoad>0;
         }
         if ((input->pos < input->size) && (endOp == ZSTD_e_end))
             endOp = ZSTD_e_flush;   /* can't end now : not all input consumed */
     }
 
     if ( (mtctx->jobReady)
       || (mtctx->inBuff.filled >= mtctx->targetSectionSize)  /* filled enough : let's compress */
       || ((endOp != ZSTD_e_continue) && (mtctx->inBuff.filled > 0))  /* something to flush : let's go */
       || ((endOp == ZSTD_e_end) && (!mtctx->frameEnded)) ) {   /* must finish the frame with a zero-size block */
         size_t const jobSize = mtctx->inBuff.filled;
         assert(mtctx->inBuff.filled <= mtctx->targetSectionSize);
         FORWARD_IF_ERROR( ZSTDMT_createCompressionJob(mtctx, jobSize, endOp) );
     }
 
     /* check for potential compressed data ready to be flushed */
     {   size_t const remainingToFlush = ZSTDMT_flushProduced(mtctx, output, !forwardInputProgress, endOp); /* block if there was no forward input progress */
         if (input->pos < input->size) return MAX(remainingToFlush, 1);  /* input not consumed : do not end flush yet */
         DEBUGLOG(5, "end of ZSTDMT_compressStream_generic: remainingToFlush = %u", (U32)remainingToFlush);
         return remainingToFlush;
     }
 }
 
 
 size_t ZSTDMT_compressStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
     FORWARD_IF_ERROR( ZSTDMT_compressStream_generic(mtctx, output, input, ZSTD_e_continue) );
 
     /* recommended next input size : fill current input buffer */
     return mtctx->targetSectionSize - mtctx->inBuff.filled;   /* note : could be zero when input buffer is fully filled and no more availability to create new job */
 }
 
 
 static size_t ZSTDMT_flushStream_internal(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output, ZSTD_EndDirective endFrame)
 {
     size_t const srcSize = mtctx->inBuff.filled;
     DEBUGLOG(5, "ZSTDMT_flushStream_internal");
 
     if ( mtctx->jobReady     /* one job ready for a worker to pick up */
       || (srcSize > 0)       /* still some data within input buffer */
       || ((endFrame==ZSTD_e_end) && !mtctx->frameEnded)) {  /* need a last 0-size block to end frame */
            DEBUGLOG(5, "ZSTDMT_flushStream_internal : create a new job (%u bytes, end:%u)",
                         (U32)srcSize, (U32)endFrame);
         FORWARD_IF_ERROR( ZSTDMT_createCompressionJob(mtctx, srcSize, endFrame) );
     }
 
     /* check if there is any data available to flush */
     return ZSTDMT_flushProduced(mtctx, output, 1 /* blockToFlush */, endFrame);
 }
 
 
 size_t ZSTDMT_flushStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output)
 {
     DEBUGLOG(5, "ZSTDMT_flushStream");
     if (mtctx->singleBlockingThread)
         return ZSTD_flushStream(mtctx->cctxPool->cctx[0], output);
     return ZSTDMT_flushStream_internal(mtctx, output, ZSTD_e_flush);
 }
 
 size_t ZSTDMT_endStream(ZSTDMT_CCtx* mtctx, ZSTD_outBuffer* output)
 {
     DEBUGLOG(4, "ZSTDMT_endStream");
     if (mtctx->singleBlockingThread)
         return ZSTD_endStream(mtctx->cctxPool->cctx[0], output);
     return ZSTDMT_flushStream_internal(mtctx, output, ZSTD_e_end);
 }
Index: head/sys/contrib/zstd/lib/decompress/huf_decompress.c
===================================================================
--- head/sys/contrib/zstd/lib/decompress/huf_decompress.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/decompress/huf_decompress.c	(revision 354777)
@@ -1,1232 +1,1234 @@
 /* ******************************************************************
    huff0 huffman decoder,
    part of Finite State Entropy library
    Copyright (C) 2013-present, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
 ****************************************************************** */
 
 /* **************************************************************
 *  Dependencies
 ****************************************************************/
 #include      /* memcpy, memset */
 #include "compiler.h"
 #include "bitstream.h"  /* BIT_* */
 #include "fse.h"        /* to compress headers */
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "error_private.h"
 
 /* **************************************************************
 *  Macros
 ****************************************************************/
 
 /* These two optional macros force the use one way or another of the two
  * Huffman decompression implementations. You can't force in both directions
  * at the same time.
  */
 #if defined(HUF_FORCE_DECOMPRESS_X1) && \
     defined(HUF_FORCE_DECOMPRESS_X2)
 #error "Cannot force the use of the X1 and X2 decoders at the same time!"
 #endif
 
 
 /* **************************************************************
 *  Error Management
 ****************************************************************/
 #define HUF_isError ERR_isError
+#ifndef CHECK_F
 #define CHECK_F(f) { size_t const err_ = (f); if (HUF_isError(err_)) return err_; }
+#endif
 
 
 /* **************************************************************
 *  Byte alignment for workSpace management
 ****************************************************************/
 #define HUF_ALIGN(x, a)         HUF_ALIGN_MASK((x), (a) - 1)
 #define HUF_ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask))
 
 
 /* **************************************************************
 *  BMI2 Variant Wrappers
 ****************************************************************/
 #if DYNAMIC_BMI2
 
 #define HUF_DGEN(fn)                                                        \
                                                                             \
     static size_t fn##_default(                                             \
                   void* dst,  size_t dstSize,                               \
             const void* cSrc, size_t cSrcSize,                              \
             const HUF_DTable* DTable)                                       \
     {                                                                       \
         return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
     }                                                                       \
                                                                             \
     static TARGET_ATTRIBUTE("bmi2") size_t fn##_bmi2(                       \
                   void* dst,  size_t dstSize,                               \
             const void* cSrc, size_t cSrcSize,                              \
             const HUF_DTable* DTable)                                       \
     {                                                                       \
         return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
     }                                                                       \
                                                                             \
     static size_t fn(void* dst, size_t dstSize, void const* cSrc,           \
                      size_t cSrcSize, HUF_DTable const* DTable, int bmi2)   \
     {                                                                       \
         if (bmi2) {                                                         \
             return fn##_bmi2(dst, dstSize, cSrc, cSrcSize, DTable);         \
         }                                                                   \
         return fn##_default(dst, dstSize, cSrc, cSrcSize, DTable);          \
     }
 
 #else
 
 #define HUF_DGEN(fn)                                                        \
     static size_t fn(void* dst, size_t dstSize, void const* cSrc,           \
                      size_t cSrcSize, HUF_DTable const* DTable, int bmi2)   \
     {                                                                       \
         (void)bmi2;                                                         \
         return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
     }
 
 #endif
 
 
 /*-***************************/
 /*  generic DTableDesc       */
 /*-***************************/
 typedef struct { BYTE maxTableLog; BYTE tableType; BYTE tableLog; BYTE reserved; } DTableDesc;
 
 static DTableDesc HUF_getDTableDesc(const HUF_DTable* table)
 {
     DTableDesc dtd;
     memcpy(&dtd, table, sizeof(dtd));
     return dtd;
 }
 
 
 #ifndef HUF_FORCE_DECOMPRESS_X2
 
 /*-***************************/
 /*  single-symbol decoding   */
 /*-***************************/
 typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX1;   /* single-symbol decoding */
 
 size_t HUF_readDTableX1_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize)
 {
     U32 tableLog = 0;
     U32 nbSymbols = 0;
     size_t iSize;
     void* const dtPtr = DTable + 1;
     HUF_DEltX1* const dt = (HUF_DEltX1*)dtPtr;
 
     U32* rankVal;
     BYTE* huffWeight;
     size_t spaceUsed32 = 0;
 
     rankVal = (U32 *)workSpace + spaceUsed32;
     spaceUsed32 += HUF_TABLELOG_ABSOLUTEMAX + 1;
     huffWeight = (BYTE *)((U32 *)workSpace + spaceUsed32);
     spaceUsed32 += HUF_ALIGN(HUF_SYMBOLVALUE_MAX + 1, sizeof(U32)) >> 2;
 
     if ((spaceUsed32 << 2) > wkspSize) return ERROR(tableLog_tooLarge);
 
     DEBUG_STATIC_ASSERT(sizeof(DTableDesc) == sizeof(HUF_DTable));
     /* memset(huffWeight, 0, sizeof(huffWeight)); */   /* is not necessary, even though some analyzer complain ... */
 
     iSize = HUF_readStats(huffWeight, HUF_SYMBOLVALUE_MAX + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
     if (HUF_isError(iSize)) return iSize;
 
     /* Table header */
     {   DTableDesc dtd = HUF_getDTableDesc(DTable);
         if (tableLog > (U32)(dtd.maxTableLog+1)) return ERROR(tableLog_tooLarge);   /* DTable too small, Huffman tree cannot fit in */
         dtd.tableType = 0;
         dtd.tableLog = (BYTE)tableLog;
         memcpy(DTable, &dtd, sizeof(dtd));
     }
 
     /* Calculate starting value for each rank */
     {   U32 n, nextRankStart = 0;
         for (n=1; n> 1;
             U32 u;
             HUF_DEltX1 D;
             D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
             for (u = rankVal[w]; u < rankVal[w] + length; u++)
                 dt[u] = D;
             rankVal[w] += length;
     }   }
 
     return iSize;
 }
 
 size_t HUF_readDTableX1(HUF_DTable* DTable, const void* src, size_t srcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_readDTableX1_wksp(DTable, src, srcSize,
                                  workSpace, sizeof(workSpace));
 }
 
 FORCE_INLINE_TEMPLATE BYTE
 HUF_decodeSymbolX1(BIT_DStream_t* Dstream, const HUF_DEltX1* dt, const U32 dtLog)
 {
     size_t const val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
     BYTE const c = dt[val].byte;
     BIT_skipBits(Dstream, dt[val].nbBits);
     return c;
 }
 
 #define HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr) \
     *ptr++ = HUF_decodeSymbolX1(DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX1_1(ptr, DStreamPtr)  \
     if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \
         HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr)
 
 #define HUF_DECODE_SYMBOLX1_2(ptr, DStreamPtr) \
     if (MEM_64bits()) \
         HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr)
 
 HINT_INLINE size_t
 HUF_decodeStreamX1(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX1* const dt, const U32 dtLog)
 {
     BYTE* const pStart = p;
 
     /* up to 4 symbols at a time */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-3)) {
         HUF_DECODE_SYMBOLX1_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX1_1(p, bitDPtr);
         HUF_DECODE_SYMBOLX1_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX1_0(p, bitDPtr);
     }
 
     /* [0-3] symbols remaining */
     if (MEM_32bits())
         while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd))
             HUF_DECODE_SYMBOLX1_0(p, bitDPtr);
 
     /* no more data to retrieve from bitstream, no need to reload */
     while (p < pEnd)
         HUF_DECODE_SYMBOLX1_0(p, bitDPtr);
 
     return pEnd-pStart;
 }
 
 FORCE_INLINE_TEMPLATE size_t
 HUF_decompress1X1_usingDTable_internal_body(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     BYTE* op = (BYTE*)dst;
     BYTE* const oend = op + dstSize;
     const void* dtPtr = DTable + 1;
     const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr;
     BIT_DStream_t bitD;
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
     U32 const dtLog = dtd.tableLog;
 
     CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) );
 
     HUF_decodeStreamX1(op, &bitD, oend, dt, dtLog);
 
     if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected);
 
     return dstSize;
 }
 
 FORCE_INLINE_TEMPLATE size_t
 HUF_decompress4X1_usingDTable_internal_body(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     /* Check */
     if (cSrcSize < 10) return ERROR(corruption_detected);  /* strict minimum : jump table + 1 byte per stream */
 
     {   const BYTE* const istart = (const BYTE*) cSrc;
         BYTE* const ostart = (BYTE*) dst;
         BYTE* const oend = ostart + dstSize;
         const void* const dtPtr = DTable + 1;
         const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr;
 
         /* Init */
         BIT_DStream_t bitD1;
         BIT_DStream_t bitD2;
         BIT_DStream_t bitD3;
         BIT_DStream_t bitD4;
         size_t const length1 = MEM_readLE16(istart);
         size_t const length2 = MEM_readLE16(istart+2);
         size_t const length3 = MEM_readLE16(istart+4);
         size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
         const BYTE* const istart1 = istart + 6;  /* jumpTable */
         const BYTE* const istart2 = istart1 + length1;
         const BYTE* const istart3 = istart2 + length2;
         const BYTE* const istart4 = istart3 + length3;
         const size_t segmentSize = (dstSize+3) / 4;
         BYTE* const opStart2 = ostart + segmentSize;
         BYTE* const opStart3 = opStart2 + segmentSize;
         BYTE* const opStart4 = opStart3 + segmentSize;
         BYTE* op1 = ostart;
         BYTE* op2 = opStart2;
         BYTE* op3 = opStart3;
         BYTE* op4 = opStart4;
         U32 endSignal = BIT_DStream_unfinished;
         DTableDesc const dtd = HUF_getDTableDesc(DTable);
         U32 const dtLog = dtd.tableLog;
 
         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
         CHECK_F( BIT_initDStream(&bitD1, istart1, length1) );
         CHECK_F( BIT_initDStream(&bitD2, istart2, length2) );
         CHECK_F( BIT_initDStream(&bitD3, istart3, length3) );
         CHECK_F( BIT_initDStream(&bitD4, istart4, length4) );
 
         /* up to 16 symbols per loop (4 symbols per stream) in 64-bit mode */
         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         while ( (endSignal==BIT_DStream_unfinished) && (op4<(oend-3)) ) {
             HUF_DECODE_SYMBOLX1_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX1_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX1_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX1_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX1_1(op1, &bitD1);
             HUF_DECODE_SYMBOLX1_1(op2, &bitD2);
             HUF_DECODE_SYMBOLX1_1(op3, &bitD3);
             HUF_DECODE_SYMBOLX1_1(op4, &bitD4);
             HUF_DECODE_SYMBOLX1_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX1_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX1_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX1_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX1_0(op1, &bitD1);
             HUF_DECODE_SYMBOLX1_0(op2, &bitD2);
             HUF_DECODE_SYMBOLX1_0(op3, &bitD3);
             HUF_DECODE_SYMBOLX1_0(op4, &bitD4);
             BIT_reloadDStream(&bitD1);
             BIT_reloadDStream(&bitD2);
             BIT_reloadDStream(&bitD3);
             BIT_reloadDStream(&bitD4);
         }
 
         /* check corruption */
         /* note : should not be necessary : op# advance in lock step, and we control op4.
          *        but curiously, binary generated by gcc 7.2 & 7.3 with -mbmi2 runs faster when >=1 test is present */
         if (op1 > opStart2) return ERROR(corruption_detected);
         if (op2 > opStart3) return ERROR(corruption_detected);
         if (op3 > opStart4) return ERROR(corruption_detected);
         /* note : op4 supposed already verified within main loop */
 
         /* finish bitStreams one by one */
         HUF_decodeStreamX1(op1, &bitD1, opStart2, dt, dtLog);
         HUF_decodeStreamX1(op2, &bitD2, opStart3, dt, dtLog);
         HUF_decodeStreamX1(op3, &bitD3, opStart4, dt, dtLog);
         HUF_decodeStreamX1(op4, &bitD4, oend,     dt, dtLog);
 
         /* check */
         { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
           if (!endCheck) return ERROR(corruption_detected); }
 
         /* decoded size */
         return dstSize;
     }
 }
 
 
 typedef size_t (*HUF_decompress_usingDTable_t)(void *dst, size_t dstSize,
                                                const void *cSrc,
                                                size_t cSrcSize,
                                                const HUF_DTable *DTable);
 
 HUF_DGEN(HUF_decompress1X1_usingDTable_internal)
 HUF_DGEN(HUF_decompress4X1_usingDTable_internal)
 
 
 
 size_t HUF_decompress1X1_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     if (dtd.tableType != 0) return ERROR(GENERIC);
     return HUF_decompress1X1_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
 size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
     size_t const hSize = HUF_readDTableX1_wksp(DCtx, cSrc, cSrcSize, workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
     return HUF_decompress1X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, /* bmi2 */ 0);
 }
 
 
 size_t HUF_decompress1X1_DCtx(HUF_DTable* DCtx, void* dst, size_t dstSize,
                               const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_decompress1X1_DCtx_wksp(DCtx, dst, dstSize, cSrc, cSrcSize,
                                        workSpace, sizeof(workSpace));
 }
 
 size_t HUF_decompress1X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     HUF_CREATE_STATIC_DTABLEX1(DTable, HUF_TABLELOG_MAX);
     return HUF_decompress1X1_DCtx (DTable, dst, dstSize, cSrc, cSrcSize);
 }
 
 size_t HUF_decompress4X1_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     if (dtd.tableType != 0) return ERROR(GENERIC);
     return HUF_decompress4X1_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
 static size_t HUF_decompress4X1_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize, int bmi2)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
     size_t const hSize = HUF_readDTableX1_wksp (dctx, cSrc, cSrcSize,
                                                 workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
     return HUF_decompress4X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
 }
 
 size_t HUF_decompress4X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize)
 {
     return HUF_decompress4X1_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, 0);
 }
 
 
 size_t HUF_decompress4X1_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
                                        workSpace, sizeof(workSpace));
 }
 size_t HUF_decompress4X1 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     HUF_CREATE_STATIC_DTABLEX1(DTable, HUF_TABLELOG_MAX);
     return HUF_decompress4X1_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
 }
 
 #endif /* HUF_FORCE_DECOMPRESS_X2 */
 
 
 #ifndef HUF_FORCE_DECOMPRESS_X1
 
 /* *************************/
 /* double-symbols decoding */
 /* *************************/
 
 typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX2;  /* double-symbols decoding */
 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
 typedef U32 rankValCol_t[HUF_TABLELOG_MAX + 1];
 typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX];
 
 
 /* HUF_fillDTableX2Level2() :
  * `rankValOrigin` must be a table of at least (HUF_TABLELOG_MAX + 1) U32 */
 static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 sizeLog, const U32 consumed,
                            const U32* rankValOrigin, const int minWeight,
                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
                            U32 nbBitsBaseline, U16 baseSeq)
 {
     HUF_DEltX2 DElt;
     U32 rankVal[HUF_TABLELOG_MAX + 1];
 
     /* get pre-calculated rankVal */
     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
 
     /* fill skipped values */
     if (minWeight>1) {
         U32 i, skipSize = rankVal[minWeight];
         MEM_writeLE16(&(DElt.sequence), baseSeq);
         DElt.nbBits   = (BYTE)(consumed);
         DElt.length   = 1;
         for (i = 0; i < skipSize; i++)
             DTable[i] = DElt;
     }
 
     /* fill DTable */
     {   U32 s; for (s=0; s= 1 */
 
             rankVal[weight] += length;
     }   }
 }
 
 
 static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog,
                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
                            const U32 nbBitsBaseline)
 {
     U32 rankVal[HUF_TABLELOG_MAX + 1];
     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
     const U32 minBits  = nbBitsBaseline - maxWeight;
     U32 s;
 
     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
 
     /* fill DTable */
     for (s=0; s= minBits) {   /* enough room for a second symbol */
             U32 sortedRank;
             int minWeight = nbBits + scaleLog;
             if (minWeight < 1) minWeight = 1;
             sortedRank = rankStart[minWeight];
             HUF_fillDTableX2Level2(DTable+start, targetLog-nbBits, nbBits,
                            rankValOrigin[nbBits], minWeight,
                            sortedList+sortedRank, sortedListSize-sortedRank,
                            nbBitsBaseline, symbol);
         } else {
             HUF_DEltX2 DElt;
             MEM_writeLE16(&(DElt.sequence), symbol);
             DElt.nbBits = (BYTE)(nbBits);
             DElt.length = 1;
             {   U32 const end = start + length;
                 U32 u;
                 for (u = start; u < end; u++) DTable[u] = DElt;
         }   }
         rankVal[weight] += length;
     }
 }
 
 size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
                        const void* src, size_t srcSize,
                              void* workSpace, size_t wkspSize)
 {
     U32 tableLog, maxW, sizeOfSort, nbSymbols;
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     U32 const maxTableLog = dtd.maxTableLog;
     size_t iSize;
     void* dtPtr = DTable+1;   /* force compiler to avoid strict-aliasing */
     HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr;
     U32 *rankStart;
 
     rankValCol_t* rankVal;
     U32* rankStats;
     U32* rankStart0;
     sortedSymbol_t* sortedSymbol;
     BYTE* weightList;
     size_t spaceUsed32 = 0;
 
     rankVal = (rankValCol_t *)((U32 *)workSpace + spaceUsed32);
     spaceUsed32 += (sizeof(rankValCol_t) * HUF_TABLELOG_MAX) >> 2;
     rankStats = (U32 *)workSpace + spaceUsed32;
     spaceUsed32 += HUF_TABLELOG_MAX + 1;
     rankStart0 = (U32 *)workSpace + spaceUsed32;
     spaceUsed32 += HUF_TABLELOG_MAX + 2;
     sortedSymbol = (sortedSymbol_t *)workSpace + (spaceUsed32 * sizeof(U32)) / sizeof(sortedSymbol_t);
     spaceUsed32 += HUF_ALIGN(sizeof(sortedSymbol_t) * (HUF_SYMBOLVALUE_MAX + 1), sizeof(U32)) >> 2;
     weightList = (BYTE *)((U32 *)workSpace + spaceUsed32);
     spaceUsed32 += HUF_ALIGN(HUF_SYMBOLVALUE_MAX + 1, sizeof(U32)) >> 2;
 
     if ((spaceUsed32 << 2) > wkspSize) return ERROR(tableLog_tooLarge);
 
     rankStart = rankStart0 + 1;
     memset(rankStats, 0, sizeof(U32) * (2 * HUF_TABLELOG_MAX + 2 + 1));
 
     DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(HUF_DTable));   /* if compiler fails here, assertion is wrong */
     if (maxTableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
     /* memset(weightList, 0, sizeof(weightList)); */  /* is not necessary, even though some analyzer complain ... */
 
     iSize = HUF_readStats(weightList, HUF_SYMBOLVALUE_MAX + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
     if (HUF_isError(iSize)) return iSize;
 
     /* check result */
     if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
 
     /* find maxWeight */
     for (maxW = tableLog; rankStats[maxW]==0; maxW--) {}  /* necessarily finds a solution before 0 */
 
     /* Get start index of each weight */
     {   U32 w, nextRankStart = 0;
         for (w=1; w> consumed;
     }   }   }   }
 
     HUF_fillDTableX2(dt, maxTableLog,
                    sortedSymbol, sizeOfSort,
                    rankStart0, rankVal, maxW,
                    tableLog+1);
 
     dtd.tableLog = (BYTE)maxTableLog;
     dtd.tableType = 1;
     memcpy(DTable, &dtd, sizeof(dtd));
     return iSize;
 }
 
 size_t HUF_readDTableX2(HUF_DTable* DTable, const void* src, size_t srcSize)
 {
   U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
   return HUF_readDTableX2_wksp(DTable, src, srcSize,
                                workSpace, sizeof(workSpace));
 }
 
 
 FORCE_INLINE_TEMPLATE U32
 HUF_decodeSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog)
 {
     size_t const val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
     memcpy(op, dt+val, 2);
     BIT_skipBits(DStream, dt[val].nbBits);
     return dt[val].length;
 }
 
 FORCE_INLINE_TEMPLATE U32
 HUF_decodeLastSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog)
 {
     size_t const val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
     memcpy(op, dt+val, 1);
     if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
     else {
         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8)) {
             BIT_skipBits(DStream, dt[val].nbBits);
             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
                 /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */
                 DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8);
     }   }
     return 1;
 }
 
 #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
     ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
     if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \
         ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
     if (MEM_64bits()) \
         ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog)
 
 HINT_INLINE size_t
 HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd,
                 const HUF_DEltX2* const dt, const U32 dtLog)
 {
     BYTE* const pStart = p;
 
     /* up to 8 symbols at a time */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-(sizeof(bitDPtr->bitContainer)-1))) {
         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
     }
 
     /* closer to end : up to 2 symbols at a time */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p <= pEnd-2))
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
 
     while (p <= pEnd-2)
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
 
     if (p < pEnd)
         p += HUF_decodeLastSymbolX2(p, bitDPtr, dt, dtLog);
 
     return p-pStart;
 }
 
 FORCE_INLINE_TEMPLATE size_t
 HUF_decompress1X2_usingDTable_internal_body(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     BIT_DStream_t bitD;
 
     /* Init */
     CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) );
 
     /* decode */
     {   BYTE* const ostart = (BYTE*) dst;
         BYTE* const oend = ostart + dstSize;
         const void* const dtPtr = DTable+1;   /* force compiler to not use strict-aliasing */
         const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;
         DTableDesc const dtd = HUF_getDTableDesc(DTable);
         HUF_decodeStreamX2(ostart, &bitD, oend, dt, dtd.tableLog);
     }
 
     /* check */
     if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected);
 
     /* decoded size */
     return dstSize;
 }
 
 
 FORCE_INLINE_TEMPLATE size_t
 HUF_decompress4X2_usingDTable_internal_body(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
 
     {   const BYTE* const istart = (const BYTE*) cSrc;
         BYTE* const ostart = (BYTE*) dst;
         BYTE* const oend = ostart + dstSize;
         const void* const dtPtr = DTable+1;
         const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;
 
         /* Init */
         BIT_DStream_t bitD1;
         BIT_DStream_t bitD2;
         BIT_DStream_t bitD3;
         BIT_DStream_t bitD4;
         size_t const length1 = MEM_readLE16(istart);
         size_t const length2 = MEM_readLE16(istart+2);
         size_t const length3 = MEM_readLE16(istart+4);
         size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
         const BYTE* const istart1 = istart + 6;  /* jumpTable */
         const BYTE* const istart2 = istart1 + length1;
         const BYTE* const istart3 = istart2 + length2;
         const BYTE* const istart4 = istart3 + length3;
         size_t const segmentSize = (dstSize+3) / 4;
         BYTE* const opStart2 = ostart + segmentSize;
         BYTE* const opStart3 = opStart2 + segmentSize;
         BYTE* const opStart4 = opStart3 + segmentSize;
         BYTE* op1 = ostart;
         BYTE* op2 = opStart2;
         BYTE* op3 = opStart3;
         BYTE* op4 = opStart4;
         U32 endSignal;
         DTableDesc const dtd = HUF_getDTableDesc(DTable);
         U32 const dtLog = dtd.tableLog;
 
         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
         CHECK_F( BIT_initDStream(&bitD1, istart1, length1) );
         CHECK_F( BIT_initDStream(&bitD2, istart2, length2) );
         CHECK_F( BIT_initDStream(&bitD3, istart3, length3) );
         CHECK_F( BIT_initDStream(&bitD4, istart4, length4) );
 
         /* 16-32 symbols per loop (4-8 symbols per stream) */
         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         for ( ; (endSignal==BIT_DStream_unfinished) & (op4<(oend-(sizeof(bitD4.bitContainer)-1))) ; ) {
             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
 
             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         }
 
         /* check corruption */
         if (op1 > opStart2) return ERROR(corruption_detected);
         if (op2 > opStart3) return ERROR(corruption_detected);
         if (op3 > opStart4) return ERROR(corruption_detected);
         /* note : op4 already verified within main loop */
 
         /* finish bitStreams one by one */
         HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
         HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
         HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
         HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
 
         /* check */
         { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
           if (!endCheck) return ERROR(corruption_detected); }
 
         /* decoded size */
         return dstSize;
     }
 }
 
 HUF_DGEN(HUF_decompress1X2_usingDTable_internal)
 HUF_DGEN(HUF_decompress4X2_usingDTable_internal)
 
 size_t HUF_decompress1X2_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     if (dtd.tableType != 1) return ERROR(GENERIC);
     return HUF_decompress1X2_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
 size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
     size_t const hSize = HUF_readDTableX2_wksp(DCtx, cSrc, cSrcSize,
                                                workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
     return HUF_decompress1X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, /* bmi2 */ 0);
 }
 
 
 size_t HUF_decompress1X2_DCtx(HUF_DTable* DCtx, void* dst, size_t dstSize,
                               const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_decompress1X2_DCtx_wksp(DCtx, dst, dstSize, cSrc, cSrcSize,
                                        workSpace, sizeof(workSpace));
 }
 
 size_t HUF_decompress1X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_TABLELOG_MAX);
     return HUF_decompress1X2_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
 }
 
 size_t HUF_decompress4X2_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const HUF_DTable* DTable)
 {
     DTableDesc dtd = HUF_getDTableDesc(DTable);
     if (dtd.tableType != 1) return ERROR(GENERIC);
     return HUF_decompress4X2_usingDTable_internal(dst, dstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 }
 
 static size_t HUF_decompress4X2_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize, int bmi2)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
     size_t hSize = HUF_readDTableX2_wksp(dctx, cSrc, cSrcSize,
                                          workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
     return HUF_decompress4X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
 }
 
 size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                    const void* cSrc, size_t cSrcSize,
                                    void* workSpace, size_t wkspSize)
 {
     return HUF_decompress4X2_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, /* bmi2 */ 0);
 }
 
 
 size_t HUF_decompress4X2_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize,
                               const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
                                        workSpace, sizeof(workSpace));
 }
 
 size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_TABLELOG_MAX);
     return HUF_decompress4X2_DCtx(DTable, dst, dstSize, cSrc, cSrcSize);
 }
 
 #endif /* HUF_FORCE_DECOMPRESS_X1 */
 
 
 /* ***********************************/
 /* Universal decompression selectors */
 /* ***********************************/
 
 size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize,
                                     const void* cSrc, size_t cSrcSize,
                                     const HUF_DTable* DTable)
 {
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
     (void)dtd;
     assert(dtd.tableType == 0);
     return HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
     (void)dtd;
     assert(dtd.tableType == 1);
     return HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 #else
     return dtd.tableType ? HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0) :
                            HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 #endif
 }
 
 size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize,
                                     const void* cSrc, size_t cSrcSize,
                                     const HUF_DTable* DTable)
 {
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
     (void)dtd;
     assert(dtd.tableType == 0);
     return HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
     (void)dtd;
     assert(dtd.tableType == 1);
     return HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 #else
     return dtd.tableType ? HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0) :
                            HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, /* bmi2 */ 0);
 #endif
 }
 
 
 #if !defined(HUF_FORCE_DECOMPRESS_X1) && !defined(HUF_FORCE_DECOMPRESS_X2)
 typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
 static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
 {
     /* single, double, quad */
     {{0,0}, {1,1}, {2,2}},  /* Q==0 : impossible */
     {{0,0}, {1,1}, {2,2}},  /* Q==1 : impossible */
     {{  38,130}, {1313, 74}, {2151, 38}},   /* Q == 2 : 12-18% */
     {{ 448,128}, {1353, 74}, {2238, 41}},   /* Q == 3 : 18-25% */
     {{ 556,128}, {1353, 74}, {2238, 47}},   /* Q == 4 : 25-32% */
     {{ 714,128}, {1418, 74}, {2436, 53}},   /* Q == 5 : 32-38% */
     {{ 883,128}, {1437, 74}, {2464, 61}},   /* Q == 6 : 38-44% */
     {{ 897,128}, {1515, 75}, {2622, 68}},   /* Q == 7 : 44-50% */
     {{ 926,128}, {1613, 75}, {2730, 75}},   /* Q == 8 : 50-56% */
     {{ 947,128}, {1729, 77}, {3359, 77}},   /* Q == 9 : 56-62% */
     {{1107,128}, {2083, 81}, {4006, 84}},   /* Q ==10 : 62-69% */
     {{1177,128}, {2379, 87}, {4785, 88}},   /* Q ==11 : 69-75% */
     {{1242,128}, {2415, 93}, {5155, 84}},   /* Q ==12 : 75-81% */
     {{1349,128}, {2644,106}, {5260,106}},   /* Q ==13 : 81-87% */
     {{1455,128}, {2422,124}, {4174,124}},   /* Q ==14 : 87-93% */
     {{ 722,128}, {1891,145}, {1936,146}},   /* Q ==15 : 93-99% */
 };
 #endif
 
 /** HUF_selectDecoder() :
  *  Tells which decoder is likely to decode faster,
  *  based on a set of pre-computed metrics.
  * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 .
  *  Assumption : 0 < dstSize <= 128 KB */
 U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize)
 {
     assert(dstSize > 0);
     assert(dstSize <= 128*1024);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
     (void)dstSize;
     (void)cSrcSize;
     return 0;
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
     (void)dstSize;
     (void)cSrcSize;
     return 1;
 #else
     /* decoder timing evaluation */
     {   U32 const Q = (cSrcSize >= dstSize) ? 15 : (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 */
         U32 const D256 = (U32)(dstSize >> 8);
         U32 const DTime0 = algoTime[Q][0].tableTime + (algoTime[Q][0].decode256Time * D256);
         U32 DTime1 = algoTime[Q][1].tableTime + (algoTime[Q][1].decode256Time * D256);
         DTime1 += DTime1 >> 3;  /* advantage to algorithm using less memory, to reduce cache eviction */
         return DTime1 < DTime0;
     }
 #endif
 }
 
 
 typedef size_t (*decompressionAlgo)(void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize);
 
 size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
 #if !defined(HUF_FORCE_DECOMPRESS_X1) && !defined(HUF_FORCE_DECOMPRESS_X2)
     static const decompressionAlgo decompress[2] = { HUF_decompress4X1, HUF_decompress4X2 };
 #endif
 
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
         (void)algoNb;
         assert(algoNb == 0);
         return HUF_decompress4X1(dst, dstSize, cSrc, cSrcSize);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
         (void)algoNb;
         assert(algoNb == 1);
         return HUF_decompress4X2(dst, dstSize, cSrc, cSrcSize);
 #else
         return decompress[algoNb](dst, dstSize, cSrc, cSrcSize);
 #endif
     }
 }
 
 size_t HUF_decompress4X_DCtx (HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
         (void)algoNb;
         assert(algoNb == 0);
         return HUF_decompress4X1_DCtx(dctx, dst, dstSize, cSrc, cSrcSize);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
         (void)algoNb;
         assert(algoNb == 1);
         return HUF_decompress4X2_DCtx(dctx, dst, dstSize, cSrc, cSrcSize);
 #else
         return algoNb ? HUF_decompress4X2_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) :
                         HUF_decompress4X1_DCtx(dctx, dst, dstSize, cSrc, cSrcSize) ;
 #endif
     }
 }
 
 size_t HUF_decompress4X_hufOnly(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_decompress4X_hufOnly_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
                                          workSpace, sizeof(workSpace));
 }
 
 
 size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst,
                                      size_t dstSize, const void* cSrc,
                                      size_t cSrcSize, void* workSpace,
                                      size_t wkspSize)
 {
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize == 0) return ERROR(corruption_detected);
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
         (void)algoNb;
         assert(algoNb == 0);
         return HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
         (void)algoNb;
         assert(algoNb == 1);
         return HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize);
 #else
         return algoNb ? HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc,
                             cSrcSize, workSpace, wkspSize):
                         HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize);
 #endif
     }
 }
 
 size_t HUF_decompress1X_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                   const void* cSrc, size_t cSrcSize,
                                   void* workSpace, size_t wkspSize)
 {
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
     if (cSrcSize == dstSize) { memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
     if (cSrcSize == 1) { memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
         (void)algoNb;
         assert(algoNb == 0);
         return HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                 cSrcSize, workSpace, wkspSize);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
         (void)algoNb;
         assert(algoNb == 1);
         return HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                 cSrcSize, workSpace, wkspSize);
 #else
         return algoNb ? HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                 cSrcSize, workSpace, wkspSize):
                         HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                 cSrcSize, workSpace, wkspSize);
 #endif
     }
 }
 
 size_t HUF_decompress1X_DCtx(HUF_DTable* dctx, void* dst, size_t dstSize,
                              const void* cSrc, size_t cSrcSize)
 {
     U32 workSpace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];
     return HUF_decompress1X_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize,
                                       workSpace, sizeof(workSpace));
 }
 
 
 size_t HUF_decompress1X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2)
 {
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
     (void)dtd;
     assert(dtd.tableType == 0);
     return HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
     (void)dtd;
     assert(dtd.tableType == 1);
     return HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
 #else
     return dtd.tableType ? HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2) :
                            HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
 #endif
 }
 
 #ifndef HUF_FORCE_DECOMPRESS_X2
 size_t HUF_decompress1X1_DCtx_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2)
 {
     const BYTE* ip = (const BYTE*) cSrc;
 
     size_t const hSize = HUF_readDTableX1_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize; cSrcSize -= hSize;
 
     return HUF_decompress1X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, bmi2);
 }
 #endif
 
 size_t HUF_decompress4X_usingDTable_bmi2(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int bmi2)
 {
     DTableDesc const dtd = HUF_getDTableDesc(DTable);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
     (void)dtd;
     assert(dtd.tableType == 0);
     return HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
     (void)dtd;
     assert(dtd.tableType == 1);
     return HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
 #else
     return dtd.tableType ? HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2) :
                            HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, bmi2);
 #endif
 }
 
 size_t HUF_decompress4X_hufOnly_wksp_bmi2(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int bmi2)
 {
     /* validation checks */
     if (dstSize == 0) return ERROR(dstSize_tooSmall);
     if (cSrcSize == 0) return ERROR(corruption_detected);
 
     {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
 #if defined(HUF_FORCE_DECOMPRESS_X1)
         (void)algoNb;
         assert(algoNb == 0);
         return HUF_decompress4X1_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, bmi2);
 #elif defined(HUF_FORCE_DECOMPRESS_X2)
         (void)algoNb;
         assert(algoNb == 1);
         return HUF_decompress4X2_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, bmi2);
 #else
         return algoNb ? HUF_decompress4X2_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, bmi2) :
                         HUF_decompress4X1_DCtx_wksp_bmi2(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, bmi2);
 #endif
     }
 }
Index: head/sys/contrib/zstd/lib/decompress/zstd_decompress.c
===================================================================
--- head/sys/contrib/zstd/lib/decompress/zstd_decompress.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/decompress/zstd_decompress.c	(revision 354777)
@@ -1,1770 +1,1769 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /* ***************************************************************
 *  Tuning parameters
 *****************************************************************/
 /*!
  * HEAPMODE :
  * Select how default decompression function ZSTD_decompress() allocates its context,
  * on stack (0), or into heap (1, default; requires malloc()).
  * Note that functions with explicit context such as ZSTD_decompressDCtx() are unaffected.
  */
 #ifndef ZSTD_HEAPMODE
 #  define ZSTD_HEAPMODE 1
 #endif
 
 /*!
 *  LEGACY_SUPPORT :
 *  if set to 1+, ZSTD_decompress() can decode older formats (v0.1+)
 */
 #ifndef ZSTD_LEGACY_SUPPORT
 #  define ZSTD_LEGACY_SUPPORT 0
 #endif
 
 /*!
  *  MAXWINDOWSIZE_DEFAULT :
  *  maximum window size accepted by DStream __by default__.
  *  Frames requiring more memory will be rejected.
  *  It's possible to set a different limit using ZSTD_DCtx_setMaxWindowSize().
  */
 #ifndef ZSTD_MAXWINDOWSIZE_DEFAULT
 #  define ZSTD_MAXWINDOWSIZE_DEFAULT (((U32)1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT) + 1)
 #endif
 
 /*!
  *  NO_FORWARD_PROGRESS_MAX :
  *  maximum allowed nb of calls to ZSTD_decompressStream()
  *  without any forward progress
  *  (defined as: no byte read from input, and no byte flushed to output)
  *  before triggering an error.
  */
 #ifndef ZSTD_NO_FORWARD_PROGRESS_MAX
 #  define ZSTD_NO_FORWARD_PROGRESS_MAX 16
 #endif
 
 
 /*-*******************************************************
 *  Dependencies
 *********************************************************/
 #include       /* memcpy, memmove, memset */
 #include "cpu.h"         /* bmi2 */
 #include "mem.h"         /* low level memory routines */
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "zstd_internal.h"  /* blockProperties_t */
 #include "zstd_decompress_internal.h"   /* ZSTD_DCtx */
 #include "zstd_ddict.h"  /* ZSTD_DDictDictContent */
 #include "zstd_decompress_block.h"   /* ZSTD_decompressBlock_internal */
 
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
 #  include "zstd_legacy.h"
 #endif
 
 
 /*-*************************************************************
 *   Context management
 ***************************************************************/
 size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx)
 {
     if (dctx==NULL) return 0;   /* support sizeof NULL */
     return sizeof(*dctx)
            + ZSTD_sizeof_DDict(dctx->ddictLocal)
            + dctx->inBuffSize + dctx->outBuffSize;
 }
 
 size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); }
 
 
 static size_t ZSTD_startingInputLength(ZSTD_format_e format)
 {
-    size_t const startingInputLength = (format==ZSTD_f_zstd1_magicless) ?
-                    ZSTD_FRAMEHEADERSIZE_PREFIX - ZSTD_FRAMEIDSIZE :
-                    ZSTD_FRAMEHEADERSIZE_PREFIX;
-    ZSTD_STATIC_ASSERT(ZSTD_FRAMEHEADERSIZE_PREFIX >= ZSTD_FRAMEIDSIZE);
+    size_t const startingInputLength = ZSTD_FRAMEHEADERSIZE_PREFIX(format);
     /* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */
     assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) );
     return startingInputLength;
 }
 
 static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx)
 {
     dctx->format = ZSTD_f_zstd1;  /* ZSTD_decompressBegin() invokes ZSTD_startingInputLength() with argument dctx->format */
     dctx->staticSize  = 0;
     dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
     dctx->ddict       = NULL;
     dctx->ddictLocal  = NULL;
     dctx->dictEnd     = NULL;
     dctx->ddictIsCold = 0;
     dctx->dictUses = ZSTD_dont_use;
     dctx->inBuff      = NULL;
     dctx->inBuffSize  = 0;
     dctx->outBuffSize = 0;
     dctx->streamStage = zdss_init;
     dctx->legacyContext = NULL;
     dctx->previousLegacyVersion = 0;
     dctx->noForwardProgress = 0;
     dctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
 }
 
 ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize)
 {
     ZSTD_DCtx* const dctx = (ZSTD_DCtx*) workspace;
 
     if ((size_t)workspace & 7) return NULL;  /* 8-aligned */
     if (workspaceSize < sizeof(ZSTD_DCtx)) return NULL;  /* minimum size */
 
     ZSTD_initDCtx_internal(dctx);
     dctx->staticSize = workspaceSize;
     dctx->inBuff = (char*)(dctx+1);
     return dctx;
 }
 
 ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
 {
     if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
 
     {   ZSTD_DCtx* const dctx = (ZSTD_DCtx*)ZSTD_malloc(sizeof(*dctx), customMem);
         if (!dctx) return NULL;
         dctx->customMem = customMem;
         ZSTD_initDCtx_internal(dctx);
         return dctx;
     }
 }
 
 ZSTD_DCtx* ZSTD_createDCtx(void)
 {
     DEBUGLOG(3, "ZSTD_createDCtx");
     return ZSTD_createDCtx_advanced(ZSTD_defaultCMem);
 }
 
 static void ZSTD_clearDict(ZSTD_DCtx* dctx)
 {
     ZSTD_freeDDict(dctx->ddictLocal);
     dctx->ddictLocal = NULL;
     dctx->ddict = NULL;
     dctx->dictUses = ZSTD_dont_use;
 }
 
 size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
 {
     if (dctx==NULL) return 0;   /* support free on NULL */
     RETURN_ERROR_IF(dctx->staticSize, memory_allocation, "not compatible with static DCtx");
     {   ZSTD_customMem const cMem = dctx->customMem;
         ZSTD_clearDict(dctx);
         ZSTD_free(dctx->inBuff, cMem);
         dctx->inBuff = NULL;
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
         if (dctx->legacyContext)
             ZSTD_freeLegacyStreamContext(dctx->legacyContext, dctx->previousLegacyVersion);
 #endif
         ZSTD_free(dctx, cMem);
         return 0;
     }
 }
 
 /* no longer useful */
 void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
 {
     size_t const toCopy = (size_t)((char*)(&dstDCtx->inBuff) - (char*)dstDCtx);
     memcpy(dstDCtx, srcDCtx, toCopy);  /* no need to copy workspace */
 }
 
 
 /*-*************************************************************
  *   Frame header decoding
  ***************************************************************/
 
 /*! ZSTD_isFrame() :
  *  Tells if the content of `buffer` starts with a valid Frame Identifier.
  *  Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
  *  Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
  *  Note 3 : Skippable Frame Identifiers are considered valid. */
 unsigned ZSTD_isFrame(const void* buffer, size_t size)
 {
     if (size < ZSTD_FRAMEIDSIZE) return 0;
     {   U32 const magic = MEM_readLE32(buffer);
         if (magic == ZSTD_MAGICNUMBER) return 1;
         if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1;
     }
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
     if (ZSTD_isLegacy(buffer, size)) return 1;
 #endif
     return 0;
 }
 
 /** ZSTD_frameHeaderSize_internal() :
  *  srcSize must be large enough to reach header size fields.
  *  note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless.
  * @return : size of the Frame Header
  *           or an error code, which can be tested with ZSTD_isError() */
 static size_t ZSTD_frameHeaderSize_internal(const void* src, size_t srcSize, ZSTD_format_e format)
 {
     size_t const minInputSize = ZSTD_startingInputLength(format);
     RETURN_ERROR_IF(srcSize < minInputSize, srcSize_wrong);
 
     {   BYTE const fhd = ((const BYTE*)src)[minInputSize-1];
         U32 const dictID= fhd & 3;
         U32 const singleSegment = (fhd >> 5) & 1;
         U32 const fcsId = fhd >> 6;
         return minInputSize + !singleSegment
              + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId]
              + (singleSegment && !fcsId);
     }
 }
 
 /** ZSTD_frameHeaderSize() :
  *  srcSize must be >= ZSTD_frameHeaderSize_prefix.
  * @return : size of the Frame Header,
  *           or an error code (if srcSize is too small) */
 size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize)
 {
     return ZSTD_frameHeaderSize_internal(src, srcSize, ZSTD_f_zstd1);
 }
 
 
 /** ZSTD_getFrameHeader_advanced() :
  *  decode Frame Header, or require larger `srcSize`.
  *  note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless
  * @return : 0, `zfhPtr` is correctly filled,
  *          >0, `srcSize` is too small, value is wanted `srcSize` amount,
  *           or an error code, which can be tested using ZSTD_isError() */
 size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t const minInputSize = ZSTD_startingInputLength(format);
 
     memset(zfhPtr, 0, sizeof(*zfhPtr));   /* not strictly necessary, but static analyzer do not understand that zfhPtr is only going to be read only if return value is zero, since they are 2 different signals */
     if (srcSize < minInputSize) return minInputSize;
     RETURN_ERROR_IF(src==NULL, GENERIC, "invalid parameter");
 
     if ( (format != ZSTD_f_zstd1_magicless)
       && (MEM_readLE32(src) != ZSTD_MAGICNUMBER) ) {
         if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
             /* skippable frame */
             if (srcSize < ZSTD_SKIPPABLEHEADERSIZE)
                 return ZSTD_SKIPPABLEHEADERSIZE; /* magic number + frame length */
             memset(zfhPtr, 0, sizeof(*zfhPtr));
             zfhPtr->frameContentSize = MEM_readLE32((const char *)src + ZSTD_FRAMEIDSIZE);
             zfhPtr->frameType = ZSTD_skippableFrame;
             return 0;
         }
         RETURN_ERROR(prefix_unknown);
     }
 
     /* ensure there is enough `srcSize` to fully read/decode frame header */
     {   size_t const fhsize = ZSTD_frameHeaderSize_internal(src, srcSize, format);
         if (srcSize < fhsize) return fhsize;
         zfhPtr->headerSize = (U32)fhsize;
     }
 
     {   BYTE const fhdByte = ip[minInputSize-1];
         size_t pos = minInputSize;
         U32 const dictIDSizeCode = fhdByte&3;
         U32 const checksumFlag = (fhdByte>>2)&1;
         U32 const singleSegment = (fhdByte>>5)&1;
         U32 const fcsID = fhdByte>>6;
         U64 windowSize = 0;
         U32 dictID = 0;
         U64 frameContentSize = ZSTD_CONTENTSIZE_UNKNOWN;
         RETURN_ERROR_IF((fhdByte & 0x08) != 0, frameParameter_unsupported,
                         "reserved bits, must be zero");
 
         if (!singleSegment) {
             BYTE const wlByte = ip[pos++];
             U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN;
             RETURN_ERROR_IF(windowLog > ZSTD_WINDOWLOG_MAX, frameParameter_windowTooLarge);
             windowSize = (1ULL << windowLog);
             windowSize += (windowSize >> 3) * (wlByte&7);
         }
         switch(dictIDSizeCode)
         {
             default: assert(0);  /* impossible */
             case 0 : break;
             case 1 : dictID = ip[pos]; pos++; break;
             case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break;
             case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break;
         }
         switch(fcsID)
         {
             default: assert(0);  /* impossible */
             case 0 : if (singleSegment) frameContentSize = ip[pos]; break;
             case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break;
             case 2 : frameContentSize = MEM_readLE32(ip+pos); break;
             case 3 : frameContentSize = MEM_readLE64(ip+pos); break;
         }
         if (singleSegment) windowSize = frameContentSize;
 
         zfhPtr->frameType = ZSTD_frame;
         zfhPtr->frameContentSize = frameContentSize;
         zfhPtr->windowSize = windowSize;
         zfhPtr->blockSizeMax = (unsigned) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
         zfhPtr->dictID = dictID;
         zfhPtr->checksumFlag = checksumFlag;
     }
     return 0;
 }
 
 /** ZSTD_getFrameHeader() :
  *  decode Frame Header, or require larger `srcSize`.
  *  note : this function does not consume input, it only reads it.
  * @return : 0, `zfhPtr` is correctly filled,
  *          >0, `srcSize` is too small, value is wanted `srcSize` amount,
  *           or an error code, which can be tested using ZSTD_isError() */
 size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize)
 {
     return ZSTD_getFrameHeader_advanced(zfhPtr, src, srcSize, ZSTD_f_zstd1);
 }
 
 
 /** ZSTD_getFrameContentSize() :
  *  compatible with legacy mode
  * @return : decompressed size of the single frame pointed to be `src` if known, otherwise
  *         - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
  *         - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */
 unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize)
 {
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
     if (ZSTD_isLegacy(src, srcSize)) {
         unsigned long long const ret = ZSTD_getDecompressedSize_legacy(src, srcSize);
         return ret == 0 ? ZSTD_CONTENTSIZE_UNKNOWN : ret;
     }
 #endif
     {   ZSTD_frameHeader zfh;
         if (ZSTD_getFrameHeader(&zfh, src, srcSize) != 0)
             return ZSTD_CONTENTSIZE_ERROR;
         if (zfh.frameType == ZSTD_skippableFrame) {
             return 0;
         } else {
             return zfh.frameContentSize;
     }   }
 }
 
 static size_t readSkippableFrameSize(void const* src, size_t srcSize)
 {
     size_t const skippableHeaderSize = ZSTD_SKIPPABLEHEADERSIZE;
     U32 sizeU32;
 
     RETURN_ERROR_IF(srcSize < ZSTD_SKIPPABLEHEADERSIZE, srcSize_wrong);
 
     sizeU32 = MEM_readLE32((BYTE const*)src + ZSTD_FRAMEIDSIZE);
     RETURN_ERROR_IF((U32)(sizeU32 + ZSTD_SKIPPABLEHEADERSIZE) < sizeU32,
                     frameParameter_unsupported);
     {
         size_t const skippableSize = skippableHeaderSize + sizeU32;
         RETURN_ERROR_IF(skippableSize > srcSize, srcSize_wrong);
         return skippableSize;
     }
 }
 
 /** ZSTD_findDecompressedSize() :
  *  compatible with legacy mode
  *  `srcSize` must be the exact length of some number of ZSTD compressed and/or
  *      skippable frames
  *  @return : decompressed size of the frames contained */
 unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize)
 {
     unsigned long long totalDstSize = 0;
 
-    while (srcSize >= ZSTD_FRAMEHEADERSIZE_PREFIX) {
+    while (srcSize >= ZSTD_startingInputLength(ZSTD_f_zstd1)) {
         U32 const magicNumber = MEM_readLE32(src);
 
         if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
             size_t const skippableSize = readSkippableFrameSize(src, srcSize);
             if (ZSTD_isError(skippableSize)) {
                 return ZSTD_CONTENTSIZE_ERROR;
             }
             assert(skippableSize <= srcSize);
 
             src = (const BYTE *)src + skippableSize;
             srcSize -= skippableSize;
             continue;
         }
 
         {   unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
             if (ret >= ZSTD_CONTENTSIZE_ERROR) return ret;
 
             /* check for overflow */
             if (totalDstSize + ret < totalDstSize) return ZSTD_CONTENTSIZE_ERROR;
             totalDstSize += ret;
         }
         {   size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize);
             if (ZSTD_isError(frameSrcSize)) {
                 return ZSTD_CONTENTSIZE_ERROR;
             }
 
             src = (const BYTE *)src + frameSrcSize;
             srcSize -= frameSrcSize;
         }
     }  /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */
 
     if (srcSize) return ZSTD_CONTENTSIZE_ERROR;
 
     return totalDstSize;
 }
 
 /** ZSTD_getDecompressedSize() :
  *  compatible with legacy mode
  * @return : decompressed size if known, 0 otherwise
              note : 0 can mean any of the following :
                    - frame content is empty
                    - decompressed size field is not present in frame header
                    - frame header unknown / not supported
                    - frame header not complete (`srcSize` too small) */
 unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize)
 {
     unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
     ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_ERROR < ZSTD_CONTENTSIZE_UNKNOWN);
     return (ret >= ZSTD_CONTENTSIZE_ERROR) ? 0 : ret;
 }
 
 
 /** ZSTD_decodeFrameHeader() :
  * `headerSize` must be the size provided by ZSTD_frameHeaderSize().
  * @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */
 static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t headerSize)
 {
     size_t const result = ZSTD_getFrameHeader_advanced(&(dctx->fParams), src, headerSize, dctx->format);
     if (ZSTD_isError(result)) return result;    /* invalid header */
     RETURN_ERROR_IF(result>0, srcSize_wrong, "headerSize too small");
 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
     /* Skip the dictID check in fuzzing mode, because it makes the search
      * harder.
      */
     RETURN_ERROR_IF(dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID),
                     dictionary_wrong);
 #endif
     if (dctx->fParams.checksumFlag) XXH64_reset(&dctx->xxhState, 0);
     return 0;
 }
 
 static ZSTD_frameSizeInfo ZSTD_errorFrameSizeInfo(size_t ret)
 {
     ZSTD_frameSizeInfo frameSizeInfo;
     frameSizeInfo.compressedSize = ret;
     frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR;
     return frameSizeInfo;
 }
 
 static ZSTD_frameSizeInfo ZSTD_findFrameSizeInfo(const void* src, size_t srcSize)
 {
     ZSTD_frameSizeInfo frameSizeInfo;
     memset(&frameSizeInfo, 0, sizeof(ZSTD_frameSizeInfo));
 
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
     if (ZSTD_isLegacy(src, srcSize))
         return ZSTD_findFrameSizeInfoLegacy(src, srcSize);
 #endif
 
     if ((srcSize >= ZSTD_SKIPPABLEHEADERSIZE)
         && (MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
         frameSizeInfo.compressedSize = readSkippableFrameSize(src, srcSize);
         assert(ZSTD_isError(frameSizeInfo.compressedSize) ||
                frameSizeInfo.compressedSize <= srcSize);
         return frameSizeInfo;
     } else {
         const BYTE* ip = (const BYTE*)src;
         const BYTE* const ipstart = ip;
         size_t remainingSize = srcSize;
         size_t nbBlocks = 0;
         ZSTD_frameHeader zfh;
 
         /* Extract Frame Header */
         {   size_t const ret = ZSTD_getFrameHeader(&zfh, src, srcSize);
             if (ZSTD_isError(ret))
                 return ZSTD_errorFrameSizeInfo(ret);
             if (ret > 0)
                 return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
         }
 
         ip += zfh.headerSize;
         remainingSize -= zfh.headerSize;
 
         /* Iterate over each block */
         while (1) {
             blockProperties_t blockProperties;
             size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
             if (ZSTD_isError(cBlockSize))
                 return ZSTD_errorFrameSizeInfo(cBlockSize);
 
             if (ZSTD_blockHeaderSize + cBlockSize > remainingSize)
                 return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
 
             ip += ZSTD_blockHeaderSize + cBlockSize;
             remainingSize -= ZSTD_blockHeaderSize + cBlockSize;
             nbBlocks++;
 
             if (blockProperties.lastBlock) break;
         }
 
         /* Final frame content checksum */
         if (zfh.checksumFlag) {
             if (remainingSize < 4)
                 return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
             ip += 4;
         }
 
         frameSizeInfo.compressedSize = ip - ipstart;
         frameSizeInfo.decompressedBound = (zfh.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN)
                                         ? zfh.frameContentSize
                                         : nbBlocks * zfh.blockSizeMax;
         return frameSizeInfo;
     }
 }
 
 /** ZSTD_findFrameCompressedSize() :
  *  compatible with legacy mode
  *  `src` must point to the start of a ZSTD frame, ZSTD legacy frame, or skippable frame
  *  `srcSize` must be at least as large as the frame contained
  *  @return : the compressed size of the frame starting at `src` */
 size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
 {
     ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize);
     return frameSizeInfo.compressedSize;
 }
 
 /** ZSTD_decompressBound() :
  *  compatible with legacy mode
  *  `src` must point to the start of a ZSTD frame or a skippeable frame
  *  `srcSize` must be at least as large as the frame contained
  *  @return : the maximum decompressed size of the compressed source
  */
 unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize)
 {
     unsigned long long bound = 0;
     /* Iterate over each frame */
     while (srcSize > 0) {
         ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize);
         size_t const compressedSize = frameSizeInfo.compressedSize;
         unsigned long long const decompressedBound = frameSizeInfo.decompressedBound;
         if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR)
             return ZSTD_CONTENTSIZE_ERROR;
         assert(srcSize >= compressedSize);
         src = (const BYTE*)src + compressedSize;
         srcSize -= compressedSize;
         bound += decompressedBound;
     }
     return bound;
 }
 
 
 /*-*************************************************************
  *   Frame decoding
  ***************************************************************/
 
 
 void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst)
 {
     if (dst != dctx->previousDstEnd) {   /* not contiguous */
         dctx->dictEnd = dctx->previousDstEnd;
         dctx->virtualStart = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
         dctx->prefixStart = dst;
         dctx->previousDstEnd = dst;
     }
 }
 
 /** ZSTD_insertBlock() :
-    insert `src` block into `dctx` history. Useful to track uncompressed blocks. */
+ *  insert `src` block into `dctx` history. Useful to track uncompressed blocks. */
 size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize)
 {
+    DEBUGLOG(5, "ZSTD_insertBlock: %u bytes", (unsigned)blockSize);
     ZSTD_checkContinuity(dctx, blockStart);
     dctx->previousDstEnd = (const char*)blockStart + blockSize;
     return blockSize;
 }
 
 
 static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity,
                           const void* src, size_t srcSize)
 {
     DEBUGLOG(5, "ZSTD_copyRawBlock");
     if (dst == NULL) {
         if (srcSize == 0) return 0;
         RETURN_ERROR(dstBuffer_null);
     }
     RETURN_ERROR_IF(srcSize > dstCapacity, dstSize_tooSmall);
     memcpy(dst, src, srcSize);
     return srcSize;
 }
 
 static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity,
                                BYTE b,
                                size_t regenSize)
 {
     if (dst == NULL) {
         if (regenSize == 0) return 0;
         RETURN_ERROR(dstBuffer_null);
     }
     RETURN_ERROR_IF(regenSize > dstCapacity, dstSize_tooSmall);
     memset(dst, b, regenSize);
     return regenSize;
 }
 
 
 /*! ZSTD_decompressFrame() :
  * @dctx must be properly initialized
  *  will update *srcPtr and *srcSizePtr,
  *  to make *srcPtr progress by one frame. */
 static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
                                    void* dst, size_t dstCapacity,
                              const void** srcPtr, size_t *srcSizePtr)
 {
     const BYTE* ip = (const BYTE*)(*srcPtr);
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* const oend = ostart + dstCapacity;
     BYTE* op = ostart;
     size_t remainingSrcSize = *srcSizePtr;
 
     DEBUGLOG(4, "ZSTD_decompressFrame (srcSize:%i)", (int)*srcSizePtr);
 
     /* check */
     RETURN_ERROR_IF(
-        remainingSrcSize < ZSTD_FRAMEHEADERSIZE_MIN+ZSTD_blockHeaderSize,
+        remainingSrcSize < ZSTD_FRAMEHEADERSIZE_MIN(dctx->format)+ZSTD_blockHeaderSize,
         srcSize_wrong);
 
     /* Frame Header */
-    {   size_t const frameHeaderSize = ZSTD_frameHeaderSize(ip, ZSTD_FRAMEHEADERSIZE_PREFIX);
+    {   size_t const frameHeaderSize = ZSTD_frameHeaderSize_internal(
+                ip, ZSTD_FRAMEHEADERSIZE_PREFIX(dctx->format), dctx->format);
         if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
         RETURN_ERROR_IF(remainingSrcSize < frameHeaderSize+ZSTD_blockHeaderSize,
                         srcSize_wrong);
         FORWARD_IF_ERROR( ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize) );
         ip += frameHeaderSize; remainingSrcSize -= frameHeaderSize;
     }
 
     /* Loop on each block */
     while (1) {
         size_t decodedSize;
         blockProperties_t blockProperties;
         size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSrcSize, &blockProperties);
         if (ZSTD_isError(cBlockSize)) return cBlockSize;
 
         ip += ZSTD_blockHeaderSize;
         remainingSrcSize -= ZSTD_blockHeaderSize;
         RETURN_ERROR_IF(cBlockSize > remainingSrcSize, srcSize_wrong);
 
         switch(blockProperties.blockType)
         {
         case bt_compressed:
             decodedSize = ZSTD_decompressBlock_internal(dctx, op, oend-op, ip, cBlockSize, /* frame */ 1);
             break;
         case bt_raw :
             decodedSize = ZSTD_copyRawBlock(op, oend-op, ip, cBlockSize);
             break;
         case bt_rle :
             decodedSize = ZSTD_setRleBlock(op, oend-op, *ip, blockProperties.origSize);
             break;
         case bt_reserved :
         default:
             RETURN_ERROR(corruption_detected);
         }
 
         if (ZSTD_isError(decodedSize)) return decodedSize;
         if (dctx->fParams.checksumFlag)
             XXH64_update(&dctx->xxhState, op, decodedSize);
         op += decodedSize;
         ip += cBlockSize;
         remainingSrcSize -= cBlockSize;
         if (blockProperties.lastBlock) break;
     }
 
     if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) {
         RETURN_ERROR_IF((U64)(op-ostart) != dctx->fParams.frameContentSize,
                         corruption_detected);
     }
     if (dctx->fParams.checksumFlag) { /* Frame content checksum verification */
         U32 const checkCalc = (U32)XXH64_digest(&dctx->xxhState);
         U32 checkRead;
         RETURN_ERROR_IF(remainingSrcSize<4, checksum_wrong);
         checkRead = MEM_readLE32(ip);
         RETURN_ERROR_IF(checkRead != checkCalc, checksum_wrong);
         ip += 4;
         remainingSrcSize -= 4;
     }
 
     /* Allow caller to get size read */
     *srcPtr = ip;
     *srcSizePtr = remainingSrcSize;
     return op-ostart;
 }
 
 static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
                                         void* dst, size_t dstCapacity,
                                   const void* src, size_t srcSize,
                                   const void* dict, size_t dictSize,
                                   const ZSTD_DDict* ddict)
 {
     void* const dststart = dst;
     int moreThan1Frame = 0;
 
     DEBUGLOG(5, "ZSTD_decompressMultiFrame");
     assert(dict==NULL || ddict==NULL);  /* either dict or ddict set, not both */
 
     if (ddict) {
         dict = ZSTD_DDict_dictContent(ddict);
         dictSize = ZSTD_DDict_dictSize(ddict);
     }
 
-    while (srcSize >= ZSTD_FRAMEHEADERSIZE_PREFIX) {
+    while (srcSize >= ZSTD_startingInputLength(dctx->format)) {
 
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
         if (ZSTD_isLegacy(src, srcSize)) {
             size_t decodedSize;
             size_t const frameSize = ZSTD_findFrameCompressedSizeLegacy(src, srcSize);
             if (ZSTD_isError(frameSize)) return frameSize;
             RETURN_ERROR_IF(dctx->staticSize, memory_allocation,
                 "legacy support is not compatible with static dctx");
 
             decodedSize = ZSTD_decompressLegacy(dst, dstCapacity, src, frameSize, dict, dictSize);
             if (ZSTD_isError(decodedSize)) return decodedSize;
 
             assert(decodedSize <=- dstCapacity);
             dst = (BYTE*)dst + decodedSize;
             dstCapacity -= decodedSize;
 
             src = (const BYTE*)src + frameSize;
             srcSize -= frameSize;
 
             continue;
         }
 #endif
 
         {   U32 const magicNumber = MEM_readLE32(src);
             DEBUGLOG(4, "reading magic number %08X (expecting %08X)",
                         (unsigned)magicNumber, ZSTD_MAGICNUMBER);
             if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
                 size_t const skippableSize = readSkippableFrameSize(src, srcSize);
                 FORWARD_IF_ERROR(skippableSize);
                 assert(skippableSize <= srcSize);
 
                 src = (const BYTE *)src + skippableSize;
                 srcSize -= skippableSize;
                 continue;
         }   }
 
         if (ddict) {
             /* we were called from ZSTD_decompress_usingDDict */
             FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(dctx, ddict));
         } else {
             /* this will initialize correctly with no dict if dict == NULL, so
              * use this in all cases but ddict */
             FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize));
         }
         ZSTD_checkContinuity(dctx, dst);
 
         {   const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity,
                                                     &src, &srcSize);
             RETURN_ERROR_IF(
                 (ZSTD_getErrorCode(res) == ZSTD_error_prefix_unknown)
              && (moreThan1Frame==1),
                 srcSize_wrong,
                 "at least one frame successfully completed, but following "
                 "bytes are garbage: it's more likely to be a srcSize error, "
                 "specifying more bytes than compressed size of frame(s). This "
                 "error message replaces ERROR(prefix_unknown), which would be "
                 "confusing, as the first header is actually correct. Note that "
                 "one could be unlucky, it might be a corruption error instead, "
                 "happening right at the place where we expect zstd magic "
                 "bytes. But this is _much_ less likely than a srcSize field "
                 "error.");
             if (ZSTD_isError(res)) return res;
             assert(res <= dstCapacity);
             dst = (BYTE*)dst + res;
             dstCapacity -= res;
         }
         moreThan1Frame = 1;
     }  /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */
 
     RETURN_ERROR_IF(srcSize, srcSize_wrong, "input not entirely consumed");
 
     return (BYTE*)dst - (BYTE*)dststart;
 }
 
 size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
                                  void* dst, size_t dstCapacity,
                            const void* src, size_t srcSize,
                            const void* dict, size_t dictSize)
 {
     return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, dict, dictSize, NULL);
 }
 
 
 static ZSTD_DDict const* ZSTD_getDDict(ZSTD_DCtx* dctx)
 {
     switch (dctx->dictUses) {
     default:
         assert(0 /* Impossible */);
         /* fall-through */
     case ZSTD_dont_use:
         ZSTD_clearDict(dctx);
         return NULL;
     case ZSTD_use_indefinitely:
         return dctx->ddict;
     case ZSTD_use_once:
         dctx->dictUses = ZSTD_dont_use;
         return dctx->ddict;
     }
 }
 
 size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     return ZSTD_decompress_usingDDict(dctx, dst, dstCapacity, src, srcSize, ZSTD_getDDict(dctx));
 }
 
 
 size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
 #if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE>=1)
     size_t regenSize;
     ZSTD_DCtx* const dctx = ZSTD_createDCtx();
     RETURN_ERROR_IF(dctx==NULL, memory_allocation);
     regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize);
     ZSTD_freeDCtx(dctx);
     return regenSize;
 #else   /* stack mode */
     ZSTD_DCtx dctx;
     ZSTD_initDCtx_internal(&dctx);
     return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize);
 #endif
 }
 
 
 /*-**************************************
 *   Advanced Streaming Decompression API
 *   Bufferless and synchronous
 ****************************************/
 size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; }
 
 ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) {
     switch(dctx->stage)
     {
     default:   /* should not happen */
         assert(0);
     case ZSTDds_getFrameHeaderSize:
     case ZSTDds_decodeFrameHeader:
         return ZSTDnit_frameHeader;
     case ZSTDds_decodeBlockHeader:
         return ZSTDnit_blockHeader;
     case ZSTDds_decompressBlock:
         return ZSTDnit_block;
     case ZSTDds_decompressLastBlock:
         return ZSTDnit_lastBlock;
     case ZSTDds_checkChecksum:
         return ZSTDnit_checksum;
     case ZSTDds_decodeSkippableHeader:
     case ZSTDds_skipFrame:
         return ZSTDnit_skippableFrame;
     }
 }
 
 static int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; }
 
 /** ZSTD_decompressContinue() :
  *  srcSize : must be the exact nb of bytes expected (see ZSTD_nextSrcSizeToDecompress())
  *  @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity)
  *            or an error code, which can be tested using ZSTD_isError() */
 size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     DEBUGLOG(5, "ZSTD_decompressContinue (srcSize:%u)", (unsigned)srcSize);
     /* Sanity check */
     RETURN_ERROR_IF(srcSize != dctx->expected, srcSize_wrong, "not allowed");
     if (dstCapacity) ZSTD_checkContinuity(dctx, dst);
 
     switch (dctx->stage)
     {
     case ZSTDds_getFrameHeaderSize :
         assert(src != NULL);
         if (dctx->format == ZSTD_f_zstd1) {  /* allows header */
             assert(srcSize >= ZSTD_FRAMEIDSIZE);  /* to read skippable magic number */
             if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {        /* skippable frame */
                 memcpy(dctx->headerBuffer, src, srcSize);
                 dctx->expected = ZSTD_SKIPPABLEHEADERSIZE - srcSize;  /* remaining to load to get full skippable frame header */
                 dctx->stage = ZSTDds_decodeSkippableHeader;
                 return 0;
         }   }
         dctx->headerSize = ZSTD_frameHeaderSize_internal(src, srcSize, dctx->format);
         if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize;
         memcpy(dctx->headerBuffer, src, srcSize);
         dctx->expected = dctx->headerSize - srcSize;
         dctx->stage = ZSTDds_decodeFrameHeader;
         return 0;
 
     case ZSTDds_decodeFrameHeader:
         assert(src != NULL);
         memcpy(dctx->headerBuffer + (dctx->headerSize - srcSize), src, srcSize);
         FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize));
         dctx->expected = ZSTD_blockHeaderSize;
         dctx->stage = ZSTDds_decodeBlockHeader;
         return 0;
 
     case ZSTDds_decodeBlockHeader:
         {   blockProperties_t bp;
             size_t const cBlockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
             if (ZSTD_isError(cBlockSize)) return cBlockSize;
             RETURN_ERROR_IF(cBlockSize > dctx->fParams.blockSizeMax, corruption_detected, "Block Size Exceeds Maximum");
             dctx->expected = cBlockSize;
             dctx->bType = bp.blockType;
             dctx->rleSize = bp.origSize;
             if (cBlockSize) {
                 dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock;
                 return 0;
             }
             /* empty block */
             if (bp.lastBlock) {
                 if (dctx->fParams.checksumFlag) {
                     dctx->expected = 4;
                     dctx->stage = ZSTDds_checkChecksum;
                 } else {
                     dctx->expected = 0; /* end of frame */
                     dctx->stage = ZSTDds_getFrameHeaderSize;
                 }
             } else {
                 dctx->expected = ZSTD_blockHeaderSize;  /* jump to next header */
                 dctx->stage = ZSTDds_decodeBlockHeader;
             }
             return 0;
         }
 
     case ZSTDds_decompressLastBlock:
     case ZSTDds_decompressBlock:
         DEBUGLOG(5, "ZSTD_decompressContinue: case ZSTDds_decompressBlock");
         {   size_t rSize;
             switch(dctx->bType)
             {
             case bt_compressed:
                 DEBUGLOG(5, "ZSTD_decompressContinue: case bt_compressed");
                 rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 1);
                 break;
             case bt_raw :
                 rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize);
                 break;
             case bt_rle :
                 rSize = ZSTD_setRleBlock(dst, dstCapacity, *(const BYTE*)src, dctx->rleSize);
                 break;
             case bt_reserved :   /* should never happen */
             default:
                 RETURN_ERROR(corruption_detected);
             }
             if (ZSTD_isError(rSize)) return rSize;
             RETURN_ERROR_IF(rSize > dctx->fParams.blockSizeMax, corruption_detected, "Decompressed Block Size Exceeds Maximum");
             DEBUGLOG(5, "ZSTD_decompressContinue: decoded size from block : %u", (unsigned)rSize);
             dctx->decodedSize += rSize;
             if (dctx->fParams.checksumFlag) XXH64_update(&dctx->xxhState, dst, rSize);
 
             if (dctx->stage == ZSTDds_decompressLastBlock) {   /* end of frame */
                 DEBUGLOG(4, "ZSTD_decompressContinue: decoded size from frame : %u", (unsigned)dctx->decodedSize);
                 RETURN_ERROR_IF(
                     dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
                  && dctx->decodedSize != dctx->fParams.frameContentSize,
                     corruption_detected);
                 if (dctx->fParams.checksumFlag) {  /* another round for frame checksum */
                     dctx->expected = 4;
                     dctx->stage = ZSTDds_checkChecksum;
                 } else {
                     dctx->expected = 0;   /* ends here */
                     dctx->stage = ZSTDds_getFrameHeaderSize;
                 }
             } else {
                 dctx->stage = ZSTDds_decodeBlockHeader;
                 dctx->expected = ZSTD_blockHeaderSize;
                 dctx->previousDstEnd = (char*)dst + rSize;
             }
             return rSize;
         }
 
     case ZSTDds_checkChecksum:
         assert(srcSize == 4);  /* guaranteed by dctx->expected */
         {   U32 const h32 = (U32)XXH64_digest(&dctx->xxhState);
             U32 const check32 = MEM_readLE32(src);
             DEBUGLOG(4, "ZSTD_decompressContinue: checksum : calculated %08X :: %08X read", (unsigned)h32, (unsigned)check32);
             RETURN_ERROR_IF(check32 != h32, checksum_wrong);
             dctx->expected = 0;
             dctx->stage = ZSTDds_getFrameHeaderSize;
             return 0;
         }
 
     case ZSTDds_decodeSkippableHeader:
         assert(src != NULL);
         assert(srcSize <= ZSTD_SKIPPABLEHEADERSIZE);
         memcpy(dctx->headerBuffer + (ZSTD_SKIPPABLEHEADERSIZE - srcSize), src, srcSize);   /* complete skippable header */
         dctx->expected = MEM_readLE32(dctx->headerBuffer + ZSTD_FRAMEIDSIZE);   /* note : dctx->expected can grow seriously large, beyond local buffer size */
         dctx->stage = ZSTDds_skipFrame;
         return 0;
 
     case ZSTDds_skipFrame:
         dctx->expected = 0;
         dctx->stage = ZSTDds_getFrameHeaderSize;
         return 0;
 
     default:
         assert(0);   /* impossible */
         RETURN_ERROR(GENERIC);   /* some compiler require default to do something */
     }
 }
 
 
 static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     dctx->dictEnd = dctx->previousDstEnd;
     dctx->virtualStart = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
     dctx->prefixStart = dict;
     dctx->previousDstEnd = (const char*)dict + dictSize;
     return 0;
 }
 
 /*! ZSTD_loadDEntropy() :
  *  dict : must point at beginning of a valid zstd dictionary.
  * @return : size of entropy tables read */
 size_t
 ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
                   const void* const dict, size_t const dictSize)
 {
     const BYTE* dictPtr = (const BYTE*)dict;
     const BYTE* const dictEnd = dictPtr + dictSize;
 
     RETURN_ERROR_IF(dictSize <= 8, dictionary_corrupted);
     assert(MEM_readLE32(dict) == ZSTD_MAGIC_DICTIONARY);   /* dict must be valid */
     dictPtr += 8;   /* skip header = magic + dictID */
 
     ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, OFTable) == offsetof(ZSTD_entropyDTables_t, LLTable) + sizeof(entropy->LLTable));
     ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, MLTable) == offsetof(ZSTD_entropyDTables_t, OFTable) + sizeof(entropy->OFTable));
     ZSTD_STATIC_ASSERT(sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable) >= HUF_DECOMPRESS_WORKSPACE_SIZE);
     {   void* const workspace = &entropy->LLTable;   /* use fse tables as temporary workspace; implies fse tables are grouped together */
         size_t const workspaceSize = sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable);
 #ifdef HUF_FORCE_DECOMPRESS_X1
         /* in minimal huffman, we always use X1 variants */
         size_t const hSize = HUF_readDTableX1_wksp(entropy->hufTable,
                                                 dictPtr, dictEnd - dictPtr,
                                                 workspace, workspaceSize);
 #else
         size_t const hSize = HUF_readDTableX2_wksp(entropy->hufTable,
                                                 dictPtr, dictEnd - dictPtr,
                                                 workspace, workspaceSize);
 #endif
         RETURN_ERROR_IF(HUF_isError(hSize), dictionary_corrupted);
         dictPtr += hSize;
     }
 
     {   short offcodeNCount[MaxOff+1];
         unsigned offcodeMaxValue = MaxOff, offcodeLog;
         size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
         RETURN_ERROR_IF(FSE_isError(offcodeHeaderSize), dictionary_corrupted);
         RETURN_ERROR_IF(offcodeMaxValue > MaxOff, dictionary_corrupted);
         RETURN_ERROR_IF(offcodeLog > OffFSELog, dictionary_corrupted);
         ZSTD_buildFSETable( entropy->OFTable,
                             offcodeNCount, offcodeMaxValue,
                             OF_base, OF_bits,
                             offcodeLog);
         dictPtr += offcodeHeaderSize;
     }
 
     {   short matchlengthNCount[MaxML+1];
         unsigned matchlengthMaxValue = MaxML, matchlengthLog;
         size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
         RETURN_ERROR_IF(FSE_isError(matchlengthHeaderSize), dictionary_corrupted);
         RETURN_ERROR_IF(matchlengthMaxValue > MaxML, dictionary_corrupted);
         RETURN_ERROR_IF(matchlengthLog > MLFSELog, dictionary_corrupted);
         ZSTD_buildFSETable( entropy->MLTable,
                             matchlengthNCount, matchlengthMaxValue,
                             ML_base, ML_bits,
                             matchlengthLog);
         dictPtr += matchlengthHeaderSize;
     }
 
     {   short litlengthNCount[MaxLL+1];
         unsigned litlengthMaxValue = MaxLL, litlengthLog;
         size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
         RETURN_ERROR_IF(FSE_isError(litlengthHeaderSize), dictionary_corrupted);
         RETURN_ERROR_IF(litlengthMaxValue > MaxLL, dictionary_corrupted);
         RETURN_ERROR_IF(litlengthLog > LLFSELog, dictionary_corrupted);
         ZSTD_buildFSETable( entropy->LLTable,
                             litlengthNCount, litlengthMaxValue,
                             LL_base, LL_bits,
                             litlengthLog);
         dictPtr += litlengthHeaderSize;
     }
 
     RETURN_ERROR_IF(dictPtr+12 > dictEnd, dictionary_corrupted);
     {   int i;
         size_t const dictContentSize = (size_t)(dictEnd - (dictPtr+12));
         for (i=0; i<3; i++) {
             U32 const rep = MEM_readLE32(dictPtr); dictPtr += 4;
-            RETURN_ERROR_IF(rep==0 || rep >= dictContentSize,
+            RETURN_ERROR_IF(rep==0 || rep > dictContentSize,
                             dictionary_corrupted);
             entropy->rep[i] = rep;
     }   }
 
     return dictPtr - (const BYTE*)dict;
 }
 
 static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     if (dictSize < 8) return ZSTD_refDictContent(dctx, dict, dictSize);
     {   U32 const magic = MEM_readLE32(dict);
         if (magic != ZSTD_MAGIC_DICTIONARY) {
             return ZSTD_refDictContent(dctx, dict, dictSize);   /* pure content mode */
     }   }
     dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
 
     /* load entropy tables */
     {   size_t const eSize = ZSTD_loadDEntropy(&dctx->entropy, dict, dictSize);
         RETURN_ERROR_IF(ZSTD_isError(eSize), dictionary_corrupted);
         dict = (const char*)dict + eSize;
         dictSize -= eSize;
     }
     dctx->litEntropy = dctx->fseEntropy = 1;
 
     /* reference dictionary content */
     return ZSTD_refDictContent(dctx, dict, dictSize);
 }
 
 size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx)
 {
     assert(dctx != NULL);
     dctx->expected = ZSTD_startingInputLength(dctx->format);  /* dctx->format must be properly set */
     dctx->stage = ZSTDds_getFrameHeaderSize;
     dctx->decodedSize = 0;
     dctx->previousDstEnd = NULL;
     dctx->prefixStart = NULL;
     dctx->virtualStart = NULL;
     dctx->dictEnd = NULL;
     dctx->entropy.hufTable[0] = (HUF_DTable)((HufLog)*0x1000001);  /* cover both little and big endian */
     dctx->litEntropy = dctx->fseEntropy = 0;
     dctx->dictID = 0;
     ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue));
     memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue));  /* initial repcodes */
     dctx->LLTptr = dctx->entropy.LLTable;
     dctx->MLTptr = dctx->entropy.MLTable;
     dctx->OFTptr = dctx->entropy.OFTable;
     dctx->HUFptr = dctx->entropy.hufTable;
     return 0;
 }
 
 size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) );
     if (dict && dictSize)
         RETURN_ERROR_IF(
             ZSTD_isError(ZSTD_decompress_insertDictionary(dctx, dict, dictSize)),
             dictionary_corrupted);
     return 0;
 }
 
 
 /* ======   ZSTD_DDict   ====== */
 
 size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
 {
     DEBUGLOG(4, "ZSTD_decompressBegin_usingDDict");
     assert(dctx != NULL);
     if (ddict) {
         const char* const dictStart = (const char*)ZSTD_DDict_dictContent(ddict);
         size_t const dictSize = ZSTD_DDict_dictSize(ddict);
         const void* const dictEnd = dictStart + dictSize;
         dctx->ddictIsCold = (dctx->dictEnd != dictEnd);
         DEBUGLOG(4, "DDict is %s",
                     dctx->ddictIsCold ? "~cold~" : "hot!");
     }
     FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) );
     if (ddict) {   /* NULL ddict is equivalent to no dictionary */
         ZSTD_copyDDictParameters(dctx, ddict);
     }
     return 0;
 }
 
 /*! ZSTD_getDictID_fromDict() :
  *  Provides the dictID stored within dictionary.
  *  if @return == 0, the dictionary is not conformant with Zstandard specification.
  *  It can still be loaded, but as a content-only dictionary. */
 unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize)
 {
     if (dictSize < 8) return 0;
     if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) return 0;
     return MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
 }
 
 /*! ZSTD_getDictID_fromFrame() :
  *  Provides the dictID required to decompress frame stored within `src`.
  *  If @return == 0, the dictID could not be decoded.
  *  This could for one of the following reasons :
  *  - The frame does not require a dictionary (most common case).
  *  - The frame was built with dictID intentionally removed.
  *    Needed dictionary is a hidden information.
  *    Note : this use case also happens when using a non-conformant dictionary.
  *  - `srcSize` is too small, and as a result, frame header could not be decoded.
  *    Note : possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`.
  *  - This is not a Zstandard frame.
  *  When identifying the exact failure cause, it's possible to use
  *  ZSTD_getFrameHeader(), which will provide a more precise error code. */
 unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize)
 {
     ZSTD_frameHeader zfp = { 0, 0, 0, ZSTD_frame, 0, 0, 0 };
     size_t const hError = ZSTD_getFrameHeader(&zfp, src, srcSize);
     if (ZSTD_isError(hError)) return 0;
     return zfp.dictID;
 }
 
 
 /*! ZSTD_decompress_usingDDict() :
 *   Decompression using a pre-digested Dictionary
 *   Use dictionary without significant overhead. */
 size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
                                   void* dst, size_t dstCapacity,
                             const void* src, size_t srcSize,
                             const ZSTD_DDict* ddict)
 {
     /* pass content and size in case legacy frames are encountered */
     return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize,
                                      NULL, 0,
                                      ddict);
 }
 
 
 /*=====================================
 *   Streaming decompression
 *====================================*/
 
 ZSTD_DStream* ZSTD_createDStream(void)
 {
     DEBUGLOG(3, "ZSTD_createDStream");
     return ZSTD_createDStream_advanced(ZSTD_defaultCMem);
 }
 
 ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize)
 {
     return ZSTD_initStaticDCtx(workspace, workspaceSize);
 }
 
 ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem)
 {
     return ZSTD_createDCtx_advanced(customMem);
 }
 
 size_t ZSTD_freeDStream(ZSTD_DStream* zds)
 {
     return ZSTD_freeDCtx(zds);
 }
 
 
 /* ***  Initialization  *** */
 
 size_t ZSTD_DStreamInSize(void)  { return ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize; }
 size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_MAX; }
 
 size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx,
                                    const void* dict, size_t dictSize,
                                          ZSTD_dictLoadMethod_e dictLoadMethod,
                                          ZSTD_dictContentType_e dictContentType)
 {
     RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong);
     ZSTD_clearDict(dctx);
-    if (dict && dictSize >= 8) {
+    if (dict && dictSize != 0) {
         dctx->ddictLocal = ZSTD_createDDict_advanced(dict, dictSize, dictLoadMethod, dictContentType, dctx->customMem);
         RETURN_ERROR_IF(dctx->ddictLocal == NULL, memory_allocation);
         dctx->ddict = dctx->ddictLocal;
         dctx->dictUses = ZSTD_use_indefinitely;
     }
     return 0;
 }
 
 size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
 }
 
 size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
 {
     return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
 }
 
 size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
 {
     FORWARD_IF_ERROR(ZSTD_DCtx_loadDictionary_advanced(dctx, prefix, prefixSize, ZSTD_dlm_byRef, dictContentType));
     dctx->dictUses = ZSTD_use_once;
     return 0;
 }
 
 size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize)
 {
     return ZSTD_DCtx_refPrefix_advanced(dctx, prefix, prefixSize, ZSTD_dct_rawContent);
 }
 
 
 /* ZSTD_initDStream_usingDict() :
- * return : expected size, aka ZSTD_FRAMEHEADERSIZE_PREFIX.
+ * return : expected size, aka ZSTD_startingInputLength().
  * this function cannot fail */
 size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize)
 {
     DEBUGLOG(4, "ZSTD_initDStream_usingDict");
     FORWARD_IF_ERROR( ZSTD_DCtx_reset(zds, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_DCtx_loadDictionary(zds, dict, dictSize) );
-    return ZSTD_FRAMEHEADERSIZE_PREFIX;
+    return ZSTD_startingInputLength(zds->format);
 }
 
 /* note : this variant can't fail */
 size_t ZSTD_initDStream(ZSTD_DStream* zds)
 {
     DEBUGLOG(4, "ZSTD_initDStream");
     return ZSTD_initDStream_usingDDict(zds, NULL);
 }
 
 /* ZSTD_initDStream_usingDDict() :
  * ddict will just be referenced, and must outlive decompression session
  * this function cannot fail */
 size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* dctx, const ZSTD_DDict* ddict)
 {
     FORWARD_IF_ERROR( ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only) );
     FORWARD_IF_ERROR( ZSTD_DCtx_refDDict(dctx, ddict) );
-    return ZSTD_FRAMEHEADERSIZE_PREFIX;
+    return ZSTD_startingInputLength(dctx->format);
 }
 
 /* ZSTD_resetDStream() :
- * return : expected size, aka ZSTD_FRAMEHEADERSIZE_PREFIX.
+ * return : expected size, aka ZSTD_startingInputLength().
  * this function cannot fail */
 size_t ZSTD_resetDStream(ZSTD_DStream* dctx)
 {
     FORWARD_IF_ERROR(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only));
-    return ZSTD_FRAMEHEADERSIZE_PREFIX;
+    return ZSTD_startingInputLength(dctx->format);
 }
 
 
 size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
 {
     RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong);
     ZSTD_clearDict(dctx);
     if (ddict) {
         dctx->ddict = ddict;
         dctx->dictUses = ZSTD_use_indefinitely;
     }
     return 0;
 }
 
 /* ZSTD_DCtx_setMaxWindowSize() :
  * note : no direct equivalence in ZSTD_DCtx_setParameter,
  * since this version sets windowSize, and the other sets windowLog */
 size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize)
 {
     ZSTD_bounds const bounds = ZSTD_dParam_getBounds(ZSTD_d_windowLogMax);
     size_t const min = (size_t)1 << bounds.lowerBound;
     size_t const max = (size_t)1 << bounds.upperBound;
     RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong);
     RETURN_ERROR_IF(maxWindowSize < min, parameter_outOfBound);
     RETURN_ERROR_IF(maxWindowSize > max, parameter_outOfBound);
     dctx->maxWindowSize = maxWindowSize;
     return 0;
 }
 
 size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format)
 {
     return ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, format);
 }
 
 ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam)
 {
     ZSTD_bounds bounds = { 0, 0, 0 };
     switch(dParam) {
         case ZSTD_d_windowLogMax:
             bounds.lowerBound = ZSTD_WINDOWLOG_ABSOLUTEMIN;
             bounds.upperBound = ZSTD_WINDOWLOG_MAX;
             return bounds;
         case ZSTD_d_format:
             bounds.lowerBound = (int)ZSTD_f_zstd1;
             bounds.upperBound = (int)ZSTD_f_zstd1_magicless;
             ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless);
             return bounds;
         default:;
     }
     bounds.error = ERROR(parameter_unsupported);
     return bounds;
 }
 
 /* ZSTD_dParam_withinBounds:
  * @return 1 if value is within dParam bounds,
  * 0 otherwise */
 static int ZSTD_dParam_withinBounds(ZSTD_dParameter dParam, int value)
 {
     ZSTD_bounds const bounds = ZSTD_dParam_getBounds(dParam);
     if (ZSTD_isError(bounds.error)) return 0;
     if (value < bounds.lowerBound) return 0;
     if (value > bounds.upperBound) return 0;
     return 1;
 }
 
 #define CHECK_DBOUNDS(p,v) {                \
     RETURN_ERROR_IF(!ZSTD_dParam_withinBounds(p, v), parameter_outOfBound); \
 }
 
 size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter dParam, int value)
 {
     RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong);
     switch(dParam) {
         case ZSTD_d_windowLogMax:
             if (value == 0) value = ZSTD_WINDOWLOG_LIMIT_DEFAULT;
             CHECK_DBOUNDS(ZSTD_d_windowLogMax, value);
             dctx->maxWindowSize = ((size_t)1) << value;
             return 0;
         case ZSTD_d_format:
             CHECK_DBOUNDS(ZSTD_d_format, value);
             dctx->format = (ZSTD_format_e)value;
             return 0;
         default:;
     }
     RETURN_ERROR(parameter_unsupported);
 }
 
 size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset)
 {
     if ( (reset == ZSTD_reset_session_only)
       || (reset == ZSTD_reset_session_and_parameters) ) {
         dctx->streamStage = zdss_init;
         dctx->noForwardProgress = 0;
     }
     if ( (reset == ZSTD_reset_parameters)
       || (reset == ZSTD_reset_session_and_parameters) ) {
         RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong);
         ZSTD_clearDict(dctx);
         dctx->format = ZSTD_f_zstd1;
         dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
     }
     return 0;
 }
 
 
 size_t ZSTD_sizeof_DStream(const ZSTD_DStream* dctx)
 {
     return ZSTD_sizeof_DCtx(dctx);
 }
 
 size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize)
 {
     size_t const blockSize = (size_t) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
     unsigned long long const neededRBSize = windowSize + blockSize + (WILDCOPY_OVERLENGTH * 2);
     unsigned long long const neededSize = MIN(frameContentSize, neededRBSize);
     size_t const minRBSize = (size_t) neededSize;
     RETURN_ERROR_IF((unsigned long long)minRBSize != neededSize,
                     frameParameter_windowTooLarge);
     return minRBSize;
 }
 
 size_t ZSTD_estimateDStreamSize(size_t windowSize)
 {
     size_t const blockSize = MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
     size_t const inBuffSize = blockSize;  /* no block can be larger */
     size_t const outBuffSize = ZSTD_decodingBufferSize_min(windowSize, ZSTD_CONTENTSIZE_UNKNOWN);
     return ZSTD_estimateDCtxSize() + inBuffSize + outBuffSize;
 }
 
 size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize)
 {
     U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX;   /* note : should be user-selectable, but requires an additional parameter (or a dctx) */
     ZSTD_frameHeader zfh;
     size_t const err = ZSTD_getFrameHeader(&zfh, src, srcSize);
     if (ZSTD_isError(err)) return err;
     RETURN_ERROR_IF(err>0, srcSize_wrong);
     RETURN_ERROR_IF(zfh.windowSize > windowSizeMax,
                     frameParameter_windowTooLarge);
     return ZSTD_estimateDStreamSize((size_t)zfh.windowSize);
 }
 
 
 /* *****   Decompression   ***** */
 
 MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
 {
     size_t const length = MIN(dstCapacity, srcSize);
     memcpy(dst, src, length);
     return length;
 }
 
 
 size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
     const char* const istart = (const char*)(input->src) + input->pos;
     const char* const iend = (const char*)(input->src) + input->size;
     const char* ip = istart;
     char* const ostart = (char*)(output->dst) + output->pos;
     char* const oend = (char*)(output->dst) + output->size;
     char* op = ostart;
     U32 someMoreWork = 1;
 
     DEBUGLOG(5, "ZSTD_decompressStream");
     RETURN_ERROR_IF(
         input->pos > input->size,
         srcSize_wrong,
         "forbidden. in: pos: %u   vs size: %u",
         (U32)input->pos, (U32)input->size);
     RETURN_ERROR_IF(
         output->pos > output->size,
         dstSize_tooSmall,
         "forbidden. out: pos: %u   vs size: %u",
         (U32)output->pos, (U32)output->size);
     DEBUGLOG(5, "input size : %u", (U32)(input->size - input->pos));
 
     while (someMoreWork) {
         switch(zds->streamStage)
         {
         case zdss_init :
             DEBUGLOG(5, "stage zdss_init => transparent reset ");
             zds->streamStage = zdss_loadHeader;
             zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
             zds->legacyVersion = 0;
             zds->hostageByte = 0;
             /* fall-through */
 
         case zdss_loadHeader :
             DEBUGLOG(5, "stage zdss_loadHeader (srcSize : %u)", (U32)(iend - ip));
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
             if (zds->legacyVersion) {
                 RETURN_ERROR_IF(zds->staticSize, memory_allocation,
                     "legacy support is incompatible with static dctx");
                 {   size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
                     if (hint==0) zds->streamStage = zdss_init;
                     return hint;
             }   }
 #endif
             {   size_t const hSize = ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format);
                 DEBUGLOG(5, "header size : %u", (U32)hSize);
                 if (ZSTD_isError(hSize)) {
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
                     U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart);
                     if (legacyVersion) {
                         ZSTD_DDict const* const ddict = ZSTD_getDDict(zds);
                         const void* const dict = ddict ? ZSTD_DDict_dictContent(ddict) : NULL;
                         size_t const dictSize = ddict ? ZSTD_DDict_dictSize(ddict) : 0;
                         DEBUGLOG(5, "ZSTD_decompressStream: detected legacy version v0.%u", legacyVersion);
                         RETURN_ERROR_IF(zds->staticSize, memory_allocation,
                             "legacy support is incompatible with static dctx");
                         FORWARD_IF_ERROR(ZSTD_initLegacyStream(&zds->legacyContext,
                                     zds->previousLegacyVersion, legacyVersion,
                                     dict, dictSize));
                         zds->legacyVersion = zds->previousLegacyVersion = legacyVersion;
                         {   size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, legacyVersion, output, input);
                             if (hint==0) zds->streamStage = zdss_init;   /* or stay in stage zdss_loadHeader */
                             return hint;
                     }   }
 #endif
                     return hSize;   /* error */
                 }
                 if (hSize != 0) {   /* need more input */
                     size_t const toLoad = hSize - zds->lhSize;   /* if hSize!=0, hSize > zds->lhSize */
                     size_t const remainingInput = (size_t)(iend-ip);
                     assert(iend >= ip);
                     if (toLoad > remainingInput) {   /* not enough input to load full header */
                         if (remainingInput > 0) {
                             memcpy(zds->headerBuffer + zds->lhSize, ip, remainingInput);
                             zds->lhSize += remainingInput;
                         }
                         input->pos = input->size;
-                        return (MAX(ZSTD_FRAMEHEADERSIZE_MIN, hSize) - zds->lhSize) + ZSTD_blockHeaderSize;   /* remaining header bytes + next block header */
+                        return (MAX((size_t)ZSTD_FRAMEHEADERSIZE_MIN(zds->format), hSize) - zds->lhSize) + ZSTD_blockHeaderSize;   /* remaining header bytes + next block header */
                     }
                     assert(ip != NULL);
                     memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad;
                     break;
             }   }
 
             /* check for single-pass mode opportunity */
             if (zds->fParams.frameContentSize && zds->fParams.windowSize /* skippable frame if == 0 */
                 && (U64)(size_t)(oend-op) >= zds->fParams.frameContentSize) {
                 size_t const cSize = ZSTD_findFrameCompressedSize(istart, iend-istart);
                 if (cSize <= (size_t)(iend-istart)) {
                     /* shortcut : using single-pass mode */
                     size_t const decompressedSize = ZSTD_decompress_usingDDict(zds, op, oend-op, istart, cSize, ZSTD_getDDict(zds));
                     if (ZSTD_isError(decompressedSize)) return decompressedSize;
                     DEBUGLOG(4, "shortcut to single-pass ZSTD_decompress_usingDDict()")
                     ip = istart + cSize;
                     op += decompressedSize;
                     zds->expected = 0;
                     zds->streamStage = zdss_init;
                     someMoreWork = 0;
                     break;
             }   }
 
             /* Consume header (see ZSTDds_decodeFrameHeader) */
             DEBUGLOG(4, "Consume header");
             FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(zds, ZSTD_getDDict(zds)));
 
             if ((MEM_readLE32(zds->headerBuffer) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {  /* skippable frame */
                 zds->expected = MEM_readLE32(zds->headerBuffer + ZSTD_FRAMEIDSIZE);
                 zds->stage = ZSTDds_skipFrame;
             } else {
                 FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(zds, zds->headerBuffer, zds->lhSize));
                 zds->expected = ZSTD_blockHeaderSize;
                 zds->stage = ZSTDds_decodeBlockHeader;
             }
 
             /* control buffer memory usage */
             DEBUGLOG(4, "Control max memory usage (%u KB <= max %u KB)",
                         (U32)(zds->fParams.windowSize >>10),
                         (U32)(zds->maxWindowSize >> 10) );
             zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN);
             RETURN_ERROR_IF(zds->fParams.windowSize > zds->maxWindowSize,
                             frameParameter_windowTooLarge);
 
             /* Adapt buffer sizes to frame header instructions */
             {   size_t const neededInBuffSize = MAX(zds->fParams.blockSizeMax, 4 /* frame checksum */);
                 size_t const neededOutBuffSize = ZSTD_decodingBufferSize_min(zds->fParams.windowSize, zds->fParams.frameContentSize);
                 if ((zds->inBuffSize < neededInBuffSize) || (zds->outBuffSize < neededOutBuffSize)) {
                     size_t const bufferSize = neededInBuffSize + neededOutBuffSize;
                     DEBUGLOG(4, "inBuff  : from %u to %u",
                                 (U32)zds->inBuffSize, (U32)neededInBuffSize);
                     DEBUGLOG(4, "outBuff : from %u to %u",
                                 (U32)zds->outBuffSize, (U32)neededOutBuffSize);
                     if (zds->staticSize) {  /* static DCtx */
                         DEBUGLOG(4, "staticSize : %u", (U32)zds->staticSize);
                         assert(zds->staticSize >= sizeof(ZSTD_DCtx));  /* controlled at init */
                         RETURN_ERROR_IF(
                             bufferSize > zds->staticSize - sizeof(ZSTD_DCtx),
                             memory_allocation);
                     } else {
                         ZSTD_free(zds->inBuff, zds->customMem);
                         zds->inBuffSize = 0;
                         zds->outBuffSize = 0;
                         zds->inBuff = (char*)ZSTD_malloc(bufferSize, zds->customMem);
                         RETURN_ERROR_IF(zds->inBuff == NULL, memory_allocation);
                     }
                     zds->inBuffSize = neededInBuffSize;
                     zds->outBuff = zds->inBuff + zds->inBuffSize;
                     zds->outBuffSize = neededOutBuffSize;
             }   }
             zds->streamStage = zdss_read;
             /* fall-through */
 
         case zdss_read:
             DEBUGLOG(5, "stage zdss_read");
             {   size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds);
                 DEBUGLOG(5, "neededInSize = %u", (U32)neededInSize);
                 if (neededInSize==0) {  /* end of frame */
                     zds->streamStage = zdss_init;
                     someMoreWork = 0;
                     break;
                 }
                 if ((size_t)(iend-ip) >= neededInSize) {  /* decode directly from src */
                     int const isSkipFrame = ZSTD_isSkipFrame(zds);
                     size_t const decodedSize = ZSTD_decompressContinue(zds,
                         zds->outBuff + zds->outStart, (isSkipFrame ? 0 : zds->outBuffSize - zds->outStart),
                         ip, neededInSize);
                     if (ZSTD_isError(decodedSize)) return decodedSize;
                     ip += neededInSize;
                     if (!decodedSize && !isSkipFrame) break;   /* this was just a header */
                     zds->outEnd = zds->outStart + decodedSize;
                     zds->streamStage = zdss_flush;
                     break;
             }   }
             if (ip==iend) { someMoreWork = 0; break; }   /* no more input */
             zds->streamStage = zdss_load;
             /* fall-through */
 
         case zdss_load:
             {   size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds);
                 size_t const toLoad = neededInSize - zds->inPos;
                 int const isSkipFrame = ZSTD_isSkipFrame(zds);
                 size_t loadedSize;
                 if (isSkipFrame) {
                     loadedSize = MIN(toLoad, (size_t)(iend-ip));
                 } else {
                     RETURN_ERROR_IF(toLoad > zds->inBuffSize - zds->inPos,
                                     corruption_detected,
                                     "should never happen");
                     loadedSize = ZSTD_limitCopy(zds->inBuff + zds->inPos, toLoad, ip, iend-ip);
                 }
                 ip += loadedSize;
                 zds->inPos += loadedSize;
                 if (loadedSize < toLoad) { someMoreWork = 0; break; }   /* not enough input, wait for more */
 
                 /* decode loaded input */
                 {   size_t const decodedSize = ZSTD_decompressContinue(zds,
                         zds->outBuff + zds->outStart, zds->outBuffSize - zds->outStart,
                         zds->inBuff, neededInSize);
                     if (ZSTD_isError(decodedSize)) return decodedSize;
                     zds->inPos = 0;   /* input is consumed */
                     if (!decodedSize && !isSkipFrame) { zds->streamStage = zdss_read; break; }   /* this was just a header */
                     zds->outEnd = zds->outStart +  decodedSize;
             }   }
             zds->streamStage = zdss_flush;
             /* fall-through */
 
         case zdss_flush:
             {   size_t const toFlushSize = zds->outEnd - zds->outStart;
                 size_t const flushedSize = ZSTD_limitCopy(op, oend-op, zds->outBuff + zds->outStart, toFlushSize);
                 op += flushedSize;
                 zds->outStart += flushedSize;
                 if (flushedSize == toFlushSize) {  /* flush completed */
                     zds->streamStage = zdss_read;
                     if ( (zds->outBuffSize < zds->fParams.frameContentSize)
                       && (zds->outStart + zds->fParams.blockSizeMax > zds->outBuffSize) ) {
                         DEBUGLOG(5, "restart filling outBuff from beginning (left:%i, needed:%u)",
                                 (int)(zds->outBuffSize - zds->outStart),
                                 (U32)zds->fParams.blockSizeMax);
                         zds->outStart = zds->outEnd = 0;
                     }
                     break;
             }   }
             /* cannot complete flush */
             someMoreWork = 0;
             break;
 
         default:
             assert(0);    /* impossible */
             RETURN_ERROR(GENERIC);   /* some compiler require default to do something */
     }   }
 
     /* result */
     input->pos = (size_t)(ip - (const char*)(input->src));
     output->pos = (size_t)(op - (char*)(output->dst));
     if ((ip==istart) && (op==ostart)) {  /* no forward progress */
         zds->noForwardProgress ++;
         if (zds->noForwardProgress >= ZSTD_NO_FORWARD_PROGRESS_MAX) {
             RETURN_ERROR_IF(op==oend, dstSize_tooSmall);
             RETURN_ERROR_IF(ip==iend, srcSize_wrong);
             assert(0);
         }
     } else {
         zds->noForwardProgress = 0;
     }
     {   size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds);
         if (!nextSrcSizeHint) {   /* frame fully decoded */
             if (zds->outEnd == zds->outStart) {  /* output fully flushed */
                 if (zds->hostageByte) {
                     if (input->pos >= input->size) {
                         /* can't release hostage (not present) */
                         zds->streamStage = zdss_read;
                         return 1;
                     }
                     input->pos++;  /* release hostage */
                 }   /* zds->hostageByte */
                 return 0;
             }  /* zds->outEnd == zds->outStart */
             if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */
                 input->pos--;   /* note : pos > 0, otherwise, impossible to finish reading last block */
                 zds->hostageByte=1;
             }
             return 1;
         }  /* nextSrcSizeHint==0 */
         nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds) == ZSTDnit_block);   /* preload header of next block */
         assert(zds->inPos <= nextSrcSizeHint);
         nextSrcSizeHint -= zds->inPos;   /* part already loaded*/
         return nextSrcSizeHint;
     }
 }
 
 size_t ZSTD_decompressStream_simpleArgs (
                             ZSTD_DCtx* dctx,
                             void* dst, size_t dstCapacity, size_t* dstPos,
                       const void* src, size_t srcSize, size_t* srcPos)
 {
     ZSTD_outBuffer output = { dst, dstCapacity, *dstPos };
     ZSTD_inBuffer  input  = { src, srcSize, *srcPos };
     /* ZSTD_compress_generic() will check validity of dstPos and srcPos */
     size_t const cErr = ZSTD_decompressStream(dctx, &output, &input);
     *dstPos = output.pos;
     *srcPos = input.pos;
     return cErr;
 }
Index: head/sys/contrib/zstd/lib/decompress/zstd_decompress_block.c
===================================================================
--- head/sys/contrib/zstd/lib/decompress/zstd_decompress_block.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/decompress/zstd_decompress_block.c	(revision 354777)
@@ -1,1322 +1,1323 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 /* zstd_decompress_block :
  * this module takes care of decompressing _compressed_ block */
 
 /*-*******************************************************
 *  Dependencies
 *********************************************************/
 #include       /* memcpy, memmove, memset */
 #include "compiler.h"    /* prefetch */
 #include "cpu.h"         /* bmi2 */
 #include "mem.h"         /* low level memory routines */
 #define FSE_STATIC_LINKING_ONLY
 #include "fse.h"
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"
 #include "zstd_internal.h"
 #include "zstd_decompress_internal.h"   /* ZSTD_DCtx */
 #include "zstd_ddict.h"  /* ZSTD_DDictDictContent */
 #include "zstd_decompress_block.h"
 
 /*_*******************************************************
 *  Macros
 **********************************************************/
 
 /* These two optional macros force the use one way or another of the two
  * ZSTD_decompressSequences implementations. You can't force in both directions
  * at the same time.
  */
 #if defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
     defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
 #error "Cannot force the use of the short and the long ZSTD_decompressSequences variants!"
 #endif
 
 
 /*_*******************************************************
 *  Memory operations
 **********************************************************/
 static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); }
 
 
 /*-*************************************************************
  *   Block decoding
  ***************************************************************/
 
 /*! ZSTD_getcBlockSize() :
  *  Provides the size of compressed block from block header `src` */
 size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
                           blockProperties_t* bpPtr)
 {
     RETURN_ERROR_IF(srcSize < ZSTD_blockHeaderSize, srcSize_wrong);
 
     {   U32 const cBlockHeader = MEM_readLE24(src);
         U32 const cSize = cBlockHeader >> 3;
         bpPtr->lastBlock = cBlockHeader & 1;
         bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3);
         bpPtr->origSize = cSize;   /* only useful for RLE */
         if (bpPtr->blockType == bt_rle) return 1;
         RETURN_ERROR_IF(bpPtr->blockType == bt_reserved, corruption_detected);
         return cSize;
     }
 }
 
 
 /* Hidden declaration for fullbench */
 size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
                           const void* src, size_t srcSize);
 /*! ZSTD_decodeLiteralsBlock() :
  * @return : nb of bytes read from src (< srcSize )
  *  note : symbol not declared but exposed for fullbench */
 size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
                           const void* src, size_t srcSize)   /* note : srcSize < BLOCKSIZE */
 {
+    DEBUGLOG(5, "ZSTD_decodeLiteralsBlock");
     RETURN_ERROR_IF(srcSize < MIN_CBLOCK_SIZE, corruption_detected);
 
     {   const BYTE* const istart = (const BYTE*) src;
         symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3);
 
         switch(litEncType)
         {
         case set_repeat:
+            DEBUGLOG(5, "set_repeat flag : re-using stats from previous compressed literals block");
             RETURN_ERROR_IF(dctx->litEntropy==0, dictionary_corrupted);
             /* fall-through */
 
         case set_compressed:
             RETURN_ERROR_IF(srcSize < 5, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for case 3");
             {   size_t lhSize, litSize, litCSize;
                 U32 singleStream=0;
                 U32 const lhlCode = (istart[0] >> 2) & 3;
                 U32 const lhc = MEM_readLE32(istart);
                 size_t hufSuccess;
                 switch(lhlCode)
                 {
                 case 0: case 1: default:   /* note : default is impossible, since lhlCode into [0..3] */
                     /* 2 - 2 - 10 - 10 */
                     singleStream = !lhlCode;
                     lhSize = 3;
                     litSize  = (lhc >> 4) & 0x3FF;
                     litCSize = (lhc >> 14) & 0x3FF;
                     break;
                 case 2:
                     /* 2 - 2 - 14 - 14 */
                     lhSize = 4;
                     litSize  = (lhc >> 4) & 0x3FFF;
                     litCSize = lhc >> 18;
                     break;
                 case 3:
                     /* 2 - 2 - 18 - 18 */
                     lhSize = 5;
                     litSize  = (lhc >> 4) & 0x3FFFF;
-                    litCSize = (lhc >> 22) + (istart[4] << 10);
+                    litCSize = (lhc >> 22) + ((size_t)istart[4] << 10);
                     break;
                 }
                 RETURN_ERROR_IF(litSize > ZSTD_BLOCKSIZE_MAX, corruption_detected);
                 RETURN_ERROR_IF(litCSize + lhSize > srcSize, corruption_detected);
 
                 /* prefetch huffman table if cold */
                 if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) {
                     PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable));
                 }
 
                 if (litEncType==set_repeat) {
                     if (singleStream) {
                         hufSuccess = HUF_decompress1X_usingDTable_bmi2(
                             dctx->litBuffer, litSize, istart+lhSize, litCSize,
                             dctx->HUFptr, dctx->bmi2);
                     } else {
                         hufSuccess = HUF_decompress4X_usingDTable_bmi2(
                             dctx->litBuffer, litSize, istart+lhSize, litCSize,
                             dctx->HUFptr, dctx->bmi2);
                     }
                 } else {
                     if (singleStream) {
 #if defined(HUF_FORCE_DECOMPRESS_X2)
                         hufSuccess = HUF_decompress1X_DCtx_wksp(
                             dctx->entropy.hufTable, dctx->litBuffer, litSize,
                             istart+lhSize, litCSize, dctx->workspace,
                             sizeof(dctx->workspace));
 #else
                         hufSuccess = HUF_decompress1X1_DCtx_wksp_bmi2(
                             dctx->entropy.hufTable, dctx->litBuffer, litSize,
                             istart+lhSize, litCSize, dctx->workspace,
                             sizeof(dctx->workspace), dctx->bmi2);
 #endif
                     } else {
                         hufSuccess = HUF_decompress4X_hufOnly_wksp_bmi2(
                             dctx->entropy.hufTable, dctx->litBuffer, litSize,
                             istart+lhSize, litCSize, dctx->workspace,
                             sizeof(dctx->workspace), dctx->bmi2);
                     }
                 }
 
                 RETURN_ERROR_IF(HUF_isError(hufSuccess), corruption_detected);
 
                 dctx->litPtr = dctx->litBuffer;
                 dctx->litSize = litSize;
                 dctx->litEntropy = 1;
                 if (litEncType==set_compressed) dctx->HUFptr = dctx->entropy.hufTable;
                 memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
                 return litCSize + lhSize;
             }
 
         case set_basic:
             {   size_t litSize, lhSize;
                 U32 const lhlCode = ((istart[0]) >> 2) & 3;
                 switch(lhlCode)
                 {
                 case 0: case 2: default:   /* note : default is impossible, since lhlCode into [0..3] */
                     lhSize = 1;
                     litSize = istart[0] >> 3;
                     break;
                 case 1:
                     lhSize = 2;
                     litSize = MEM_readLE16(istart) >> 4;
                     break;
                 case 3:
                     lhSize = 3;
                     litSize = MEM_readLE24(istart) >> 4;
                     break;
                 }
 
                 if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) {  /* risk reading beyond src buffer with wildcopy */
                     RETURN_ERROR_IF(litSize+lhSize > srcSize, corruption_detected);
                     memcpy(dctx->litBuffer, istart+lhSize, litSize);
                     dctx->litPtr = dctx->litBuffer;
                     dctx->litSize = litSize;
                     memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH);
                     return lhSize+litSize;
                 }
                 /* direct reference into compressed stream */
                 dctx->litPtr = istart+lhSize;
                 dctx->litSize = litSize;
                 return lhSize+litSize;
             }
 
         case set_rle:
             {   U32 const lhlCode = ((istart[0]) >> 2) & 3;
                 size_t litSize, lhSize;
                 switch(lhlCode)
                 {
                 case 0: case 2: default:   /* note : default is impossible, since lhlCode into [0..3] */
                     lhSize = 1;
                     litSize = istart[0] >> 3;
                     break;
                 case 1:
                     lhSize = 2;
                     litSize = MEM_readLE16(istart) >> 4;
                     break;
                 case 3:
                     lhSize = 3;
                     litSize = MEM_readLE24(istart) >> 4;
                     RETURN_ERROR_IF(srcSize<4, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4");
                     break;
                 }
                 RETURN_ERROR_IF(litSize > ZSTD_BLOCKSIZE_MAX, corruption_detected);
                 memset(dctx->litBuffer, istart[lhSize], litSize + WILDCOPY_OVERLENGTH);
                 dctx->litPtr = dctx->litBuffer;
                 dctx->litSize = litSize;
                 return lhSize+1;
             }
         default:
             RETURN_ERROR(corruption_detected, "impossible");
         }
     }
 }
 
 /* Default FSE distribution tables.
  * These are pre-calculated FSE decoding tables using default distributions as defined in specification :
  * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#default-distributions
  * They were generated programmatically with following method :
  * - start from default distributions, present in /lib/common/zstd_internal.h
  * - generate tables normally, using ZSTD_buildFSETable()
  * - printout the content of tables
  * - pretify output, report below, test with fuzzer to ensure it's correct */
 
 /* Default FSE distribution table for Literal Lengths */
 static const ZSTD_seqSymbol LL_defaultDTable[(1<tableLog = 0;
     DTableH->fastMode = 0;
 
     cell->nbBits = 0;
     cell->nextState = 0;
     assert(nbAddBits < 255);
     cell->nbAdditionalBits = (BYTE)nbAddBits;
     cell->baseValue = baseValue;
 }
 
 
 /* ZSTD_buildFSETable() :
  * generate FSE decoding table for one symbol (ll, ml or off)
  * cannot fail if input is valid =>
  * all inputs are presumed validated at this stage */
 void
 ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
             const short* normalizedCounter, unsigned maxSymbolValue,
             const U32* baseValue, const U32* nbAdditionalBits,
             unsigned tableLog)
 {
     ZSTD_seqSymbol* const tableDecode = dt+1;
     U16 symbolNext[MaxSeq+1];
 
     U32 const maxSV1 = maxSymbolValue + 1;
     U32 const tableSize = 1 << tableLog;
     U32 highThreshold = tableSize-1;
 
     /* Sanity Checks */
     assert(maxSymbolValue <= MaxSeq);
     assert(tableLog <= MaxFSELog);
 
     /* Init, lay down lowprob symbols */
     {   ZSTD_seqSymbol_header DTableH;
         DTableH.tableLog = tableLog;
         DTableH.fastMode = 1;
         {   S16 const largeLimit= (S16)(1 << (tableLog-1));
             U32 s;
             for (s=0; s= largeLimit) DTableH.fastMode=0;
-                    symbolNext[s] = normalizedCounter[s];
+                    assert(normalizedCounter[s]>=0);
+                    symbolNext[s] = (U16)normalizedCounter[s];
         }   }   }
         memcpy(dt, &DTableH, sizeof(DTableH));
     }
 
     /* Spread symbols */
     {   U32 const tableMask = tableSize-1;
         U32 const step = FSE_TABLESTEP(tableSize);
         U32 s, position = 0;
         for (s=0; s highThreshold) position = (position + step) & tableMask;   /* lowprob area */
         }   }
         assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */
     }
 
     /* Build Decoding table */
     {   U32 u;
         for (u=0; u max, corruption_detected);
         {   U32 const symbol = *(const BYTE*)src;
             U32 const baseline = baseValue[symbol];
             U32 const nbBits = nbAdditionalBits[symbol];
             ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits);
         }
         *DTablePtr = DTableSpace;
         return 1;
     case set_basic :
         *DTablePtr = defaultTable;
         return 0;
     case set_repeat:
         RETURN_ERROR_IF(!flagRepeatTable, corruption_detected);
         /* prefetch FSE table if used */
         if (ddictIsCold && (nbSeq > 24 /* heuristic */)) {
             const void* const pStart = *DTablePtr;
             size_t const pSize = sizeof(ZSTD_seqSymbol) * (SEQSYMBOL_TABLE_SIZE(maxLog));
             PREFETCH_AREA(pStart, pSize);
         }
         return 0;
     case set_compressed :
         {   unsigned tableLog;
             S16 norm[MaxSeq+1];
             size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
             RETURN_ERROR_IF(FSE_isError(headerSize), corruption_detected);
             RETURN_ERROR_IF(tableLog > maxLog, corruption_detected);
             ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog);
             *DTablePtr = DTableSpace;
             return headerSize;
         }
     default :
         assert(0);
         RETURN_ERROR(GENERIC, "impossible");
     }
 }
 
 size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
                              const void* src, size_t srcSize)
 {
     const BYTE* const istart = (const BYTE* const)src;
     const BYTE* const iend = istart + srcSize;
     const BYTE* ip = istart;
     int nbSeq;
     DEBUGLOG(5, "ZSTD_decodeSeqHeaders");
 
     /* check */
     RETURN_ERROR_IF(srcSize < MIN_SEQUENCES_SIZE, srcSize_wrong);
 
     /* SeqHead */
     nbSeq = *ip++;
     if (!nbSeq) {
         *nbSeqPtr=0;
         RETURN_ERROR_IF(srcSize != 1, srcSize_wrong);
         return 1;
     }
     if (nbSeq > 0x7F) {
         if (nbSeq == 0xFF) {
             RETURN_ERROR_IF(ip+2 > iend, srcSize_wrong);
             nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2;
         } else {
             RETURN_ERROR_IF(ip >= iend, srcSize_wrong);
             nbSeq = ((nbSeq-0x80)<<8) + *ip++;
         }
     }
     *nbSeqPtr = nbSeq;
 
     /* FSE table descriptors */
     RETURN_ERROR_IF(ip+1 > iend, srcSize_wrong); /* minimum possible size: 1 byte for symbol encoding types */
     {   symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6);
         symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3);
         symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3);
         ip++;
 
         /* Build DTables */
         {   size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr,
                                                       LLtype, MaxLL, LLFSELog,
                                                       ip, iend-ip,
                                                       LL_base, LL_bits,
                                                       LL_defaultDTable, dctx->fseEntropy,
                                                       dctx->ddictIsCold, nbSeq);
             RETURN_ERROR_IF(ZSTD_isError(llhSize), corruption_detected);
             ip += llhSize;
         }
 
         {   size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr,
                                                       OFtype, MaxOff, OffFSELog,
                                                       ip, iend-ip,
                                                       OF_base, OF_bits,
                                                       OF_defaultDTable, dctx->fseEntropy,
                                                       dctx->ddictIsCold, nbSeq);
             RETURN_ERROR_IF(ZSTD_isError(ofhSize), corruption_detected);
             ip += ofhSize;
         }
 
         {   size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr,
                                                       MLtype, MaxML, MLFSELog,
                                                       ip, iend-ip,
                                                       ML_base, ML_bits,
                                                       ML_defaultDTable, dctx->fseEntropy,
                                                       dctx->ddictIsCold, nbSeq);
             RETURN_ERROR_IF(ZSTD_isError(mlhSize), corruption_detected);
             ip += mlhSize;
         }
     }
 
     return ip-istart;
 }
 
 
 typedef struct {
     size_t litLength;
     size_t matchLength;
     size_t offset;
     const BYTE* match;
 } seq_t;
 
 typedef struct {
     size_t state;
     const ZSTD_seqSymbol* table;
 } ZSTD_fseState;
 
 typedef struct {
     BIT_DStream_t DStream;
     ZSTD_fseState stateLL;
     ZSTD_fseState stateOffb;
     ZSTD_fseState stateML;
     size_t prevOffset[ZSTD_REP_NUM];
     const BYTE* prefixStart;
     const BYTE* dictEnd;
     size_t pos;
 } seqState_t;
 
+/*! ZSTD_overlapCopy8() :
+ *  Copies 8 bytes from ip to op and updates op and ip where ip <= op.
+ *  If the offset is < 8 then the offset is spread to at least 8 bytes.
+ *
+ *  Precondition: *ip <= *op
+ *  Postcondition: *op - *op >= 8
+ */
+static void ZSTD_overlapCopy8(BYTE** op, BYTE const** ip, size_t offset) {
+    assert(*ip <= *op);
+    if (offset < 8) {
+        /* close range match, overlap */
+        static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };   /* added */
+        static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };   /* subtracted */
+        int const sub2 = dec64table[offset];
+        (*op)[0] = (*ip)[0];
+        (*op)[1] = (*ip)[1];
+        (*op)[2] = (*ip)[2];
+        (*op)[3] = (*ip)[3];
+        *ip += dec32table[offset];
+        ZSTD_copy4(*op+4, *ip);
+        *ip -= sub2;
+    } else {
+        ZSTD_copy8(*op, *ip);
+    }
+    *ip += 8;
+    *op += 8;
+    assert(*op - *ip >= 8);
+}
 
-/* ZSTD_execSequenceLast7():
- * exceptional case : decompress a match starting within last 7 bytes of output buffer.
- * requires more careful checks, to ensure there is no overflow.
- * performance does not matter though.
- * note : this case is supposed to be never generated "naturally" by reference encoder,
- *        since in most cases it needs at least 8 bytes to look for a match.
- *        but it's allowed by the specification. */
+/*! ZSTD_safecopy() :
+ *  Specialized version of memcpy() that is allowed to READ up to WILDCOPY_OVERLENGTH past the input buffer
+ *  and write up to 16 bytes past oend_w (op >= oend_w is allowed).
+ *  This function is only called in the uncommon case where the sequence is near the end of the block. It
+ *  should be fast for a single long sequence, but can be slow for several short sequences.
+ *
+ *  @param ovtype controls the overlap detection
+ *         - ZSTD_no_overlap: The source and destination are guaranteed to be at least WILDCOPY_VECLEN bytes apart.
+ *         - ZSTD_overlap_src_before_dst: The src and dst may overlap and may be any distance apart.
+ *           The src buffer must be before the dst buffer.
+ */
+static void ZSTD_safecopy(BYTE* op, BYTE* const oend_w, BYTE const* ip, ptrdiff_t length, ZSTD_overlap_e ovtype) {
+    ptrdiff_t const diff = op - ip;
+    BYTE* const oend = op + length;
+
+    assert((ovtype == ZSTD_no_overlap && (diff <= -8 || diff >= 8 || op >= oend_w)) ||
+           (ovtype == ZSTD_overlap_src_before_dst && diff >= 0));
+
+    if (length < 8) {
+        /* Handle short lengths. */
+        while (op < oend) *op++ = *ip++;
+        return;
+    }
+    if (ovtype == ZSTD_overlap_src_before_dst) {
+        /* Copy 8 bytes and ensure the offset >= 8 when there can be overlap. */
+        assert(length >= 8);
+        ZSTD_overlapCopy8(&op, &ip, diff);
+        assert(op - ip >= 8);
+        assert(op <= oend);
+    }
+
+    if (oend <= oend_w) {
+        /* No risk of overwrite. */
+        ZSTD_wildcopy(op, ip, length, ovtype);
+        return;
+    }
+    if (op <= oend_w) {
+        /* Wildcopy until we get close to the end. */
+        assert(oend > oend_w);
+        ZSTD_wildcopy(op, ip, oend_w - op, ovtype);
+        ip += oend_w - op;
+        op = oend_w;
+    }
+    /* Handle the leftovers. */
+    while (op < oend) *op++ = *ip++;
+}
+
+/* ZSTD_execSequenceEnd():
+ * This version handles cases that are near the end of the output buffer. It requires
+ * more careful checks to make sure there is no overflow. By separating out these hard
+ * and unlikely cases, we can speed up the common cases.
+ *
+ * NOTE: This function needs to be fast for a single long sequence, but doesn't need
+ * to be optimized for many small sequences, since those fall into ZSTD_execSequence().
+ */
 FORCE_NOINLINE
-size_t ZSTD_execSequenceLast7(BYTE* op,
-                              BYTE* const oend, seq_t sequence,
-                              const BYTE** litPtr, const BYTE* const litLimit,
-                              const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd)
+size_t ZSTD_execSequenceEnd(BYTE* op,
+                            BYTE* const oend, seq_t sequence,
+                            const BYTE** litPtr, const BYTE* const litLimit,
+                            const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
 {
     BYTE* const oLitEnd = op + sequence.litLength;
     size_t const sequenceLength = sequence.litLength + sequence.matchLength;
     BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
     const BYTE* const iLitEnd = *litPtr + sequence.litLength;
     const BYTE* match = oLitEnd - sequence.offset;
+    BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
 
-    /* check */
-    RETURN_ERROR_IF(oMatchEnd>oend, dstSize_tooSmall, "last match must fit within dstBuffer");
+    /* bounds checks */
+    assert(oLitEnd < oMatchEnd);
+    RETURN_ERROR_IF(oMatchEnd > oend, dstSize_tooSmall, "last match must fit within dstBuffer");
     RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "try to read beyond literal buffer");
 
     /* copy literals */
-    while (op < oLitEnd) *op++ = *(*litPtr)++;
+    ZSTD_safecopy(op, oend_w, *litPtr, sequence.litLength, ZSTD_no_overlap);
+    op = oLitEnd;
+    *litPtr = iLitEnd;
 
     /* copy Match */
-    if (sequence.offset > (size_t)(oLitEnd - base)) {
+    if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
         /* offset beyond prefix */
-        RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - vBase),corruption_detected);
-        match = dictEnd - (base-match);
+        RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected);
+        match = dictEnd - (prefixStart-match);
         if (match + sequence.matchLength <= dictEnd) {
             memmove(oLitEnd, match, sequence.matchLength);
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
         {   size_t const length1 = dictEnd - match;
             memmove(oLitEnd, match, length1);
             op = oLitEnd + length1;
             sequence.matchLength -= length1;
-            match = base;
+            match = prefixStart;
     }   }
-    while (op < oMatchEnd) *op++ = *match++;
+    ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst);
     return sequenceLength;
 }
 
-
 HINT_INLINE
 size_t ZSTD_execSequence(BYTE* op,
                          BYTE* const oend, seq_t sequence,
                          const BYTE** litPtr, const BYTE* const litLimit,
                          const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
 {
     BYTE* const oLitEnd = op + sequence.litLength;
     size_t const sequenceLength = sequence.litLength + sequence.matchLength;
     BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
     BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
     const BYTE* const iLitEnd = *litPtr + sequence.litLength;
     const BYTE* match = oLitEnd - sequence.offset;
 
-    /* check */
-    RETURN_ERROR_IF(oMatchEnd>oend, dstSize_tooSmall, "last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend");
-    RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "over-read beyond lit buffer");
-    if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd);
+    /* Errors and uncommon cases handled here. */
+    assert(oLitEnd < oMatchEnd);
+    if (iLitEnd > litLimit || oMatchEnd > oend_w)
+        return ZSTD_execSequenceEnd(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd);
 
-    /* copy Literals */
-    if (sequence.litLength > 8)
-        ZSTD_wildcopy_16min(op, (*litPtr), sequence.litLength, ZSTD_no_overlap);   /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
-    else
-        ZSTD_copy8(op, *litPtr);
+    /* Assumptions (everything else goes into ZSTD_execSequenceEnd()) */
+    assert(iLitEnd <= litLimit /* Literal length is in bounds */);
+    assert(oLitEnd <= oend_w /* Can wildcopy literals */);
+    assert(oMatchEnd <= oend_w /* Can wildcopy matches */);
+
+    /* Copy Literals:
+     * Split out litLength <= 16 since it is nearly always true. +1.6% on gcc-9.
+     * We likely don't need the full 32-byte wildcopy.
+     */
+    assert(WILDCOPY_OVERLENGTH >= 16);
+    ZSTD_copy16(op, (*litPtr));
+    if (sequence.litLength > 16) {
+        ZSTD_wildcopy(op+16, (*litPtr)+16, sequence.litLength-16, ZSTD_no_overlap);
+    }
     op = oLitEnd;
     *litPtr = iLitEnd;   /* update for next sequence */
 
-    /* copy Match */
+    /* Copy Match */
     if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
         /* offset beyond prefix -> go into extDict */
         RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected);
         match = dictEnd + (match - prefixStart);
         if (match + sequence.matchLength <= dictEnd) {
             memmove(oLitEnd, match, sequence.matchLength);
             return sequenceLength;
         }
         /* span extDict & currentPrefixSegment */
         {   size_t const length1 = dictEnd - match;
             memmove(oLitEnd, match, length1);
             op = oLitEnd + length1;
             sequence.matchLength -= length1;
             match = prefixStart;
-            if (op > oend_w || sequence.matchLength < MINMATCH) {
-              U32 i;
-              for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i];
-              return sequenceLength;
-            }
     }   }
-    /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */
+    /* Match within prefix of 1 or more bytes */
+    assert(op <= oMatchEnd);
+    assert(oMatchEnd <= oend_w);
+    assert(match >= prefixStart);
+    assert(sequence.matchLength >= 1);
 
-    /* match within prefix */
-    if (sequence.offset < 8) {
-        /* close range match, overlap */
-        static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };   /* added */
-        static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };   /* subtracted */
-        int const sub2 = dec64table[sequence.offset];
-        op[0] = match[0];
-        op[1] = match[1];
-        op[2] = match[2];
-        op[3] = match[3];
-        match += dec32table[sequence.offset];
-        ZSTD_copy4(op+4, match);
-        match -= sub2;
-    } else {
-        ZSTD_copy8(op, match);
+    /* Nearly all offsets are >= WILDCOPY_VECLEN bytes, which means we can use wildcopy
+     * without overlap checking.
+     */
+    if (sequence.offset >= WILDCOPY_VECLEN) {
+        /* We bet on a full wildcopy for matches, since we expect matches to be
+         * longer than literals (in general). In silesia, ~10% of matches are longer
+         * than 16 bytes.
+         */
+        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap);
+        return sequenceLength;
     }
-    op += 8; match += 8;
+    assert(sequence.offset < WILDCOPY_VECLEN);
 
-    if (oMatchEnd > oend-(16-MINMATCH)) {
-        if (op < oend_w) {
-            ZSTD_wildcopy(op, match, oend_w - op, ZSTD_overlap_src_before_dst);
-            match += oend_w - op;
-            op = oend_w;
-        }
-        while (op < oMatchEnd) *op++ = *match++;
-    } else {
-        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8, ZSTD_overlap_src_before_dst);   /* works even if matchLength < 8 */
-    }
-    return sequenceLength;
-}
+    /* Copy 8 bytes and spread the offset to be >= 8. */
+    ZSTD_overlapCopy8(&op, &match, sequence.offset);
 
-
-HINT_INLINE
-size_t ZSTD_execSequenceLong(BYTE* op,
-                             BYTE* const oend, seq_t sequence,
-                             const BYTE** litPtr, const BYTE* const litLimit,
-                             const BYTE* const prefixStart, const BYTE* const dictStart, const BYTE* const dictEnd)
-{
-    BYTE* const oLitEnd = op + sequence.litLength;
-    size_t const sequenceLength = sequence.litLength + sequence.matchLength;
-    BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
-    BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;
-    const BYTE* const iLitEnd = *litPtr + sequence.litLength;
-    const BYTE* match = sequence.match;
-
-    /* check */
-    RETURN_ERROR_IF(oMatchEnd > oend, dstSize_tooSmall, "last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend");
-    RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "over-read beyond lit buffer");
-    if (oLitEnd > oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, dictStart, dictEnd);
-
-    /* copy Literals */
-    if (sequence.litLength > 8)
-        ZSTD_wildcopy_16min(op, *litPtr, sequence.litLength, ZSTD_no_overlap);   /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */
-    else
-        ZSTD_copy8(op, *litPtr);  /* note : op <= oLitEnd <= oend_w == oend - 8 */
-
-    op = oLitEnd;
-    *litPtr = iLitEnd;   /* update for next sequence */
-
-    /* copy Match */
-    if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
-        /* offset beyond prefix */
-        RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - dictStart), corruption_detected);
-        if (match + sequence.matchLength <= dictEnd) {
-            memmove(oLitEnd, match, sequence.matchLength);
-            return sequenceLength;
-        }
-        /* span extDict & currentPrefixSegment */
-        {   size_t const length1 = dictEnd - match;
-            memmove(oLitEnd, match, length1);
-            op = oLitEnd + length1;
-            sequence.matchLength -= length1;
-            match = prefixStart;
-            if (op > oend_w || sequence.matchLength < MINMATCH) {
-              U32 i;
-              for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i];
-              return sequenceLength;
-            }
-    }   }
-    assert(op <= oend_w);
-    assert(sequence.matchLength >= MINMATCH);
-
-    /* match within prefix */
-    if (sequence.offset < 8) {
-        /* close range match, overlap */
-        static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };   /* added */
-        static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };   /* subtracted */
-        int const sub2 = dec64table[sequence.offset];
-        op[0] = match[0];
-        op[1] = match[1];
-        op[2] = match[2];
-        op[3] = match[3];
-        match += dec32table[sequence.offset];
-        ZSTD_copy4(op+4, match);
-        match -= sub2;
-    } else {
-        ZSTD_copy8(op, match);
+    /* If the match length is > 8 bytes, then continue with the wildcopy. */
+    if (sequence.matchLength > 8) {
+        assert(op < oMatchEnd);
+        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8, ZSTD_overlap_src_before_dst);
     }
-    op += 8; match += 8;
-
-    if (oMatchEnd > oend-(16-MINMATCH)) {
-        if (op < oend_w) {
-            ZSTD_wildcopy(op, match, oend_w - op, ZSTD_overlap_src_before_dst);
-            match += oend_w - op;
-            op = oend_w;
-        }
-        while (op < oMatchEnd) *op++ = *match++;
-    } else {
-        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8, ZSTD_overlap_src_before_dst);   /* works even if matchLength < 8 */
-    }
     return sequenceLength;
 }
 
 static void
 ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt)
 {
     const void* ptr = dt;
     const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr;
     DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
     DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits",
                 (U32)DStatePtr->state, DTableH->tableLog);
     BIT_reloadDStream(bitD);
     DStatePtr->table = dt + 1;
 }
 
 FORCE_INLINE_TEMPLATE void
 ZSTD_updateFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD)
 {
     ZSTD_seqSymbol const DInfo = DStatePtr->table[DStatePtr->state];
     U32 const nbBits = DInfo.nbBits;
     size_t const lowBits = BIT_readBits(bitD, nbBits);
     DStatePtr->state = DInfo.nextState + lowBits;
 }
 
 /* We need to add at most (ZSTD_WINDOWLOG_MAX_32 - 1) bits to read the maximum
  * offset bits. But we can only read at most (STREAM_ACCUMULATOR_MIN_32 - 1)
  * bits before reloading. This value is the maximum number of bytes we read
  * after reloading when we are decoding long offsets.
  */
 #define LONG_OFFSETS_MAX_EXTRA_BITS_32                       \
     (ZSTD_WINDOWLOG_MAX_32 > STREAM_ACCUMULATOR_MIN_32       \
         ? ZSTD_WINDOWLOG_MAX_32 - STREAM_ACCUMULATOR_MIN_32  \
         : 0)
 
 typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e;
 
 #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
 FORCE_INLINE_TEMPLATE seq_t
 ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
 {
     seq_t seq;
     U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits;
     U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits;
     U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits;
     U32 const totalBits = llBits+mlBits+ofBits;
     U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue;
     U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue;
     U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue;
 
     /* sequence */
     {   size_t offset;
         if (!ofBits)
             offset = 0;
         else {
             ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
             ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
             assert(ofBits <= MaxOff);
             if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) {
                 U32 const extraBits = ofBits - MIN(ofBits, 32 - seqState->DStream.bitsConsumed);
                 offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
                 BIT_reloadDStream(&seqState->DStream);
                 if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits);
                 assert(extraBits <= LONG_OFFSETS_MAX_EXTRA_BITS_32);   /* to avoid another reload */
             } else {
                 offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/);   /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
                 if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
             }
         }
 
         if (ofBits <= 1) {
             offset += (llBase==0);
             if (offset) {
                 size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
                 temp += !temp;   /* 0 is not valid; input is corrupted; force offset to 1 */
                 if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
                 seqState->prevOffset[1] = seqState->prevOffset[0];
                 seqState->prevOffset[0] = offset = temp;
             } else {  /* offset == 0 */
                 offset = seqState->prevOffset[0];
             }
         } else {
             seqState->prevOffset[2] = seqState->prevOffset[1];
             seqState->prevOffset[1] = seqState->prevOffset[0];
             seqState->prevOffset[0] = offset;
         }
         seq.offset = offset;
     }
 
     seq.matchLength = mlBase
                     + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/) : 0);  /* <=  16 bits */
     if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
         BIT_reloadDStream(&seqState->DStream);
     if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
         BIT_reloadDStream(&seqState->DStream);
     /* Ensure there are enough bits to read the rest of data in 64-bit mode. */
     ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
 
     seq.litLength = llBase
                   + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits/*>0*/) : 0);    /* <=  16 bits */
     if (MEM_32bits())
         BIT_reloadDStream(&seqState->DStream);
 
     DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u",
                 (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
 
     /* ANS state update */
     ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream);    /* <=  9 bits */
     ZSTD_updateFseState(&seqState->stateML, &seqState->DStream);    /* <=  9 bits */
     if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);    /* <= 18 bits */
     ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream);  /* <=  8 bits */
 
     return seq;
 }
 
 FORCE_INLINE_TEMPLATE size_t
 DONT_VECTORIZE
 ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
                                void* dst, size_t maxDstSize,
                          const void* seqStart, size_t seqSize, int nbSeq,
                          const ZSTD_longOffset_e isLongOffset)
 {
     const BYTE* ip = (const BYTE*)seqStart;
     const BYTE* const iend = ip + seqSize;
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* const oend = ostart + maxDstSize;
     BYTE* op = ostart;
     const BYTE* litPtr = dctx->litPtr;
     const BYTE* const litEnd = litPtr + dctx->litSize;
     const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
     const BYTE* const vBase = (const BYTE*) (dctx->virtualStart);
     const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
     DEBUGLOG(5, "ZSTD_decompressSequences_body");
 
     /* Regen sequences */
     if (nbSeq) {
         seqState_t seqState;
         dctx->fseEntropy = 1;
         { U32 i; for (i=0; ientropy.rep[i]; }
         RETURN_ERROR_IF(
             ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)),
             corruption_detected);
         ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
         ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
 
         ZSTD_STATIC_ASSERT(
                 BIT_DStream_unfinished < BIT_DStream_completed &&
                 BIT_DStream_endOfBuffer < BIT_DStream_completed &&
                 BIT_DStream_completed < BIT_DStream_overflow);
 
         for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) {
             nbSeq--;
             {   seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
                 size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd);
                 DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
                 if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
                 op += oneSeqSize;
         }   }
 
         /* check if reached exact end */
         DEBUGLOG(5, "ZSTD_decompressSequences_body: after decode loop, remaining nbSeq : %i", nbSeq);
         RETURN_ERROR_IF(nbSeq, corruption_detected);
         RETURN_ERROR_IF(BIT_reloadDStream(&seqState.DStream) < BIT_DStream_completed, corruption_detected);
         /* save reps for next block */
         { U32 i; for (i=0; ientropy.rep[i] = (U32)(seqState.prevOffset[i]); }
     }
 
     /* last literal segment */
     {   size_t const lastLLSize = litEnd - litPtr;
         RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall);
         memcpy(op, litPtr, lastLLSize);
         op += lastLLSize;
     }
 
     return op-ostart;
 }
 
 static size_t
 ZSTD_decompressSequences_default(ZSTD_DCtx* dctx,
                                  void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset)
 {
     return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */
 
 
 
 #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
 FORCE_INLINE_TEMPLATE seq_t
 ZSTD_decodeSequenceLong(seqState_t* seqState, ZSTD_longOffset_e const longOffsets)
 {
     seq_t seq;
     U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits;
     U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits;
     U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits;
     U32 const totalBits = llBits+mlBits+ofBits;
     U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue;
     U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue;
     U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue;
 
     /* sequence */
     {   size_t offset;
         if (!ofBits)
             offset = 0;
         else {
             ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
             ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
             assert(ofBits <= MaxOff);
             if (MEM_32bits() && longOffsets) {
                 U32 const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN_32-1);
                 offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
                 if (MEM_32bits() || extraBits) BIT_reloadDStream(&seqState->DStream);
                 if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits);
             } else {
                 offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits);   /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
                 if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
             }
         }
 
         if (ofBits <= 1) {
             offset += (llBase==0);
             if (offset) {
                 size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
                 temp += !temp;   /* 0 is not valid; input is corrupted; force offset to 1 */
                 if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
                 seqState->prevOffset[1] = seqState->prevOffset[0];
                 seqState->prevOffset[0] = offset = temp;
             } else {
                 offset = seqState->prevOffset[0];
             }
         } else {
             seqState->prevOffset[2] = seqState->prevOffset[1];
             seqState->prevOffset[1] = seqState->prevOffset[0];
             seqState->prevOffset[0] = offset;
         }
         seq.offset = offset;
     }
 
     seq.matchLength = mlBase + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0);  /* <=  16 bits */
     if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
         BIT_reloadDStream(&seqState->DStream);
     if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
         BIT_reloadDStream(&seqState->DStream);
     /* Verify that there is enough bits to read the rest of the data in 64-bit mode. */
     ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
 
     seq.litLength = llBase + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0);    /* <=  16 bits */
     if (MEM_32bits())
         BIT_reloadDStream(&seqState->DStream);
 
     {   size_t const pos = seqState->pos + seq.litLength;
         const BYTE* const matchBase = (seq.offset > pos) ? seqState->dictEnd : seqState->prefixStart;
         seq.match = matchBase + pos - seq.offset;  /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted.
                                                     * No consequence though : no memory access will occur, overly large offset will be detected in ZSTD_execSequenceLong() */
         seqState->pos = pos + seq.matchLength;
     }
 
     /* ANS state update */
     ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream);    /* <=  9 bits */
     ZSTD_updateFseState(&seqState->stateML, &seqState->DStream);    /* <=  9 bits */
     if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);    /* <= 18 bits */
     ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream);  /* <=  8 bits */
 
     return seq;
 }
 
 FORCE_INLINE_TEMPLATE size_t
 ZSTD_decompressSequencesLong_body(
                                ZSTD_DCtx* dctx,
                                void* dst, size_t maxDstSize,
                          const void* seqStart, size_t seqSize, int nbSeq,
                          const ZSTD_longOffset_e isLongOffset)
 {
     const BYTE* ip = (const BYTE*)seqStart;
     const BYTE* const iend = ip + seqSize;
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* const oend = ostart + maxDstSize;
     BYTE* op = ostart;
     const BYTE* litPtr = dctx->litPtr;
     const BYTE* const litEnd = litPtr + dctx->litSize;
     const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
     const BYTE* const dictStart = (const BYTE*) (dctx->virtualStart);
     const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
 
     /* Regen sequences */
     if (nbSeq) {
 #define STORED_SEQS 4
 #define STORED_SEQS_MASK (STORED_SEQS-1)
 #define ADVANCED_SEQS 4
         seq_t sequences[STORED_SEQS];
         int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS);
         seqState_t seqState;
         int seqNb;
         dctx->fseEntropy = 1;
         { int i; for (i=0; ientropy.rep[i]; }
         seqState.prefixStart = prefixStart;
         seqState.pos = (size_t)(op-prefixStart);
         seqState.dictEnd = dictEnd;
         assert(iend >= ip);
         RETURN_ERROR_IF(
             ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)),
             corruption_detected);
         ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
         ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
         ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
 
         /* prepare in advance */
         for (seqNb=0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && (seqNbentropy.rep[i] = (U32)(seqState.prevOffset[i]); }
     }
 
     /* last literal segment */
     {   size_t const lastLLSize = litEnd - litPtr;
         RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall);
         memcpy(op, litPtr, lastLLSize);
         op += lastLLSize;
     }
 
     return op-ostart;
 }
 
 static size_t
 ZSTD_decompressSequencesLong_default(ZSTD_DCtx* dctx,
                                  void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset)
 {
     return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */
 
 
 
 #if DYNAMIC_BMI2
 
 #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
 static TARGET_ATTRIBUTE("bmi2") size_t
 DONT_VECTORIZE
 ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx,
                                  void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset)
 {
     return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */
 
 #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
 static TARGET_ATTRIBUTE("bmi2") size_t
 ZSTD_decompressSequencesLong_bmi2(ZSTD_DCtx* dctx,
                                  void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset)
 {
     return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */
 
 #endif /* DYNAMIC_BMI2 */
 
 typedef size_t (*ZSTD_decompressSequences_t)(
                             ZSTD_DCtx* dctx,
                             void* dst, size_t maxDstSize,
                             const void* seqStart, size_t seqSize, int nbSeq,
                             const ZSTD_longOffset_e isLongOffset);
 
 #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
 static size_t
 ZSTD_decompressSequences(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize,
                    const void* seqStart, size_t seqSize, int nbSeq,
                    const ZSTD_longOffset_e isLongOffset)
 {
     DEBUGLOG(5, "ZSTD_decompressSequences");
 #if DYNAMIC_BMI2
     if (dctx->bmi2) {
         return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
     }
 #endif
   return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */
 
 
 #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
 /* ZSTD_decompressSequencesLong() :
  * decompression function triggered when a minimum share of offsets is considered "long",
  * aka out of cache.
  * note : "long" definition seems overloaded here, sometimes meaning "wider than bitstream register", and sometimes meaning "farther than memory cache distance".
  * This function will try to mitigate main memory latency through the use of prefetching */
 static size_t
 ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx,
                              void* dst, size_t maxDstSize,
                              const void* seqStart, size_t seqSize, int nbSeq,
                              const ZSTD_longOffset_e isLongOffset)
 {
     DEBUGLOG(5, "ZSTD_decompressSequencesLong");
 #if DYNAMIC_BMI2
     if (dctx->bmi2) {
         return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
     }
 #endif
   return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
 }
 #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */
 
 
 
 #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
     !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
 /* ZSTD_getLongOffsetsShare() :
  * condition : offTable must be valid
  * @return : "share" of long offsets (arbitrarily defined as > (1<<23))
  *           compared to maximum possible of (1< 22) total += 1;
     }
 
     assert(tableLog <= OffFSELog);
     total <<= (OffFSELog - tableLog);  /* scale to OffFSELog */
 
     return total;
 }
 #endif
 
 
 size_t
 ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize, const int frame)
 {   /* blockType == blockCompressed */
     const BYTE* ip = (const BYTE*)src;
     /* isLongOffset must be true if there are long offsets.
      * Offsets are long if they are larger than 2^STREAM_ACCUMULATOR_MIN.
      * We don't expect that to be the case in 64-bit mode.
      * In block mode, window size is not known, so we have to be conservative.
      * (note: but it could be evaluated from current-lowLimit)
      */
     ZSTD_longOffset_e const isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (!frame || (dctx->fParams.windowSize > (1ULL << STREAM_ACCUMULATOR_MIN))));
     DEBUGLOG(5, "ZSTD_decompressBlock_internal (size : %u)", (U32)srcSize);
 
     RETURN_ERROR_IF(srcSize >= ZSTD_BLOCKSIZE_MAX, srcSize_wrong);
 
     /* Decode literals section */
     {   size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize);
         DEBUGLOG(5, "ZSTD_decodeLiteralsBlock : %u", (U32)litCSize);
         if (ZSTD_isError(litCSize)) return litCSize;
         ip += litCSize;
         srcSize -= litCSize;
     }
 
     /* Build Decoding Tables */
     {
         /* These macros control at build-time which decompressor implementation
          * we use. If neither is defined, we do some inspection and dispatch at
          * runtime.
          */
 #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
     !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
         int usePrefetchDecoder = dctx->ddictIsCold;
 #endif
         int nbSeq;
         size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize);
         if (ZSTD_isError(seqHSize)) return seqHSize;
         ip += seqHSize;
         srcSize -= seqHSize;
 
 #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
     !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
         if ( !usePrefetchDecoder
           && (!frame || (dctx->fParams.windowSize > (1<<24)))
           && (nbSeq>ADVANCED_SEQS) ) {  /* could probably use a larger nbSeq limit */
             U32 const shareLongOffsets = ZSTD_getLongOffsetsShare(dctx->OFTptr);
             U32 const minShare = MEM_64bits() ? 7 : 20; /* heuristic values, correspond to 2.73% and 7.81% */
             usePrefetchDecoder = (shareLongOffsets >= minShare);
         }
 #endif
 
         dctx->ddictIsCold = 0;
 
 #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
     !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
         if (usePrefetchDecoder)
 #endif
 #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
             return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
 #endif
 
 #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
         /* else */
         return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
 #endif
     }
 }
 
 
 size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx,
                             void* dst, size_t dstCapacity,
                       const void* src, size_t srcSize)
 {
     size_t dSize;
     ZSTD_checkContinuity(dctx, dst);
     dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 0);
     dctx->previousDstEnd = (char*)dst + dSize;
     return dSize;
 }
Index: head/sys/contrib/zstd/lib/deprecated/zbuff.h
===================================================================
--- head/sys/contrib/zstd/lib/deprecated/zbuff.h	(revision 354776)
+++ head/sys/contrib/zstd/lib/deprecated/zbuff.h	(revision 354777)
@@ -1,213 +1,214 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 /* ***************************************************************
 *  NOTES/WARNINGS
 ******************************************************************/
 /* The streaming API defined here is deprecated.
  * Consider migrating towards ZSTD_compressStream() API in `zstd.h`
  * See 'lib/README.md'.
  *****************************************************************/
 
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 #ifndef ZSTD_BUFFERED_H_23987
 #define ZSTD_BUFFERED_H_23987
 
 /* *************************************
 *  Dependencies
 ***************************************/
 #include       /* size_t */
 #include "zstd.h"        /* ZSTD_CStream, ZSTD_DStream, ZSTDLIB_API */
 
 
 /* ***************************************************************
 *  Compiler specifics
 *****************************************************************/
 /* Deprecation warnings */
 /* Should these warnings be a problem,
-   it is generally possible to disable them,
-   typically with -Wno-deprecated-declarations for gcc
-   or _CRT_SECURE_NO_WARNINGS in Visual.
-   Otherwise, it's also possible to define ZBUFF_DISABLE_DEPRECATE_WARNINGS */
+ * it is generally possible to disable them,
+ * typically with -Wno-deprecated-declarations for gcc
+ * or _CRT_SECURE_NO_WARNINGS in Visual.
+ * Otherwise, it's also possible to define ZBUFF_DISABLE_DEPRECATE_WARNINGS
+ */
 #ifdef ZBUFF_DISABLE_DEPRECATE_WARNINGS
 #  define ZBUFF_DEPRECATED(message) ZSTDLIB_API  /* disable deprecation warnings */
 #else
 #  if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */
 #    define ZBUFF_DEPRECATED(message) [[deprecated(message)]] ZSTDLIB_API
-#  elif (defined(__GNUC__) && (__GNUC__ >= 5)) || defined(__clang__)
+#  elif (defined(GNUC) && (GNUC > 4 || (GNUC == 4 && GNUC_MINOR >= 5))) || defined(__clang__)
 #    define ZBUFF_DEPRECATED(message) ZSTDLIB_API __attribute__((deprecated(message)))
 #  elif defined(__GNUC__) && (__GNUC__ >= 3)
 #    define ZBUFF_DEPRECATED(message) ZSTDLIB_API __attribute__((deprecated))
 #  elif defined(_MSC_VER)
 #    define ZBUFF_DEPRECATED(message) ZSTDLIB_API __declspec(deprecated(message))
 #  else
 #    pragma message("WARNING: You need to implement ZBUFF_DEPRECATED for this compiler")
 #    define ZBUFF_DEPRECATED(message) ZSTDLIB_API
 #  endif
 #endif /* ZBUFF_DISABLE_DEPRECATE_WARNINGS */
 
 
 /* *************************************
 *  Streaming functions
 ***************************************/
 /* This is the easier "buffered" streaming API,
 *  using an internal buffer to lift all restrictions on user-provided buffers
 *  which can be any size, any place, for both input and output.
 *  ZBUFF and ZSTD are 100% interoperable,
 *  frames created by one can be decoded by the other one */
 
 typedef ZSTD_CStream ZBUFF_CCtx;
 ZBUFF_DEPRECATED("use ZSTD_createCStream") ZBUFF_CCtx* ZBUFF_createCCtx(void);
 ZBUFF_DEPRECATED("use ZSTD_freeCStream")   size_t      ZBUFF_freeCCtx(ZBUFF_CCtx* cctx);
 
 ZBUFF_DEPRECATED("use ZSTD_initCStream")           size_t ZBUFF_compressInit(ZBUFF_CCtx* cctx, int compressionLevel);
 ZBUFF_DEPRECATED("use ZSTD_initCStream_usingDict") size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
 
 ZBUFF_DEPRECATED("use ZSTD_compressStream") size_t ZBUFF_compressContinue(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr, const void* src, size_t* srcSizePtr);
 ZBUFF_DEPRECATED("use ZSTD_flushStream")    size_t ZBUFF_compressFlush(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr);
 ZBUFF_DEPRECATED("use ZSTD_endStream")      size_t ZBUFF_compressEnd(ZBUFF_CCtx* cctx, void* dst, size_t* dstCapacityPtr);
 
 /*-*************************************************
 *  Streaming compression - howto
 *
 *  A ZBUFF_CCtx object is required to track streaming operation.
 *  Use ZBUFF_createCCtx() and ZBUFF_freeCCtx() to create/release resources.
 *  ZBUFF_CCtx objects can be reused multiple times.
 *
 *  Start by initializing ZBUF_CCtx.
 *  Use ZBUFF_compressInit() to start a new compression operation.
 *  Use ZBUFF_compressInitDictionary() for a compression which requires a dictionary.
 *
 *  Use ZBUFF_compressContinue() repetitively to consume input stream.
 *  *srcSizePtr and *dstCapacityPtr can be any size.
 *  The function will report how many bytes were read or written within *srcSizePtr and *dstCapacityPtr.
 *  Note that it may not consume the entire input, in which case it's up to the caller to present again remaining data.
 *  The content of `dst` will be overwritten (up to *dstCapacityPtr) at each call, so save its content if it matters or change @dst .
 *  @return : a hint to preferred nb of bytes to use as input for next function call (it's just a hint, to improve latency)
 *            or an error code, which can be tested using ZBUFF_isError().
 *
 *  At any moment, it's possible to flush whatever data remains within buffer, using ZBUFF_compressFlush().
 *  The nb of bytes written into `dst` will be reported into *dstCapacityPtr.
 *  Note that the function cannot output more than *dstCapacityPtr,
 *  therefore, some content might still be left into internal buffer if *dstCapacityPtr is too small.
 *  @return : nb of bytes still present into internal buffer (0 if it's empty)
 *            or an error code, which can be tested using ZBUFF_isError().
 *
 *  ZBUFF_compressEnd() instructs to finish a frame.
 *  It will perform a flush and write frame epilogue.
 *  The epilogue is required for decoders to consider a frame completed.
 *  Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.
 *  In which case, call again ZBUFF_compressFlush() to complete the flush.
 *  @return : nb of bytes still present into internal buffer (0 if it's empty)
 *            or an error code, which can be tested using ZBUFF_isError().
 *
 *  Hint : _recommended buffer_ sizes (not compulsory) : ZBUFF_recommendedCInSize() / ZBUFF_recommendedCOutSize()
 *  input : ZBUFF_recommendedCInSize==128 KB block size is the internal unit, use this value to reduce intermediate stages (better latency)
 *  output : ZBUFF_recommendedCOutSize==ZSTD_compressBound(128 KB) + 3 + 3 : ensures it's always possible to write/flush/end a full block. Skip some buffering.
 *  By using both, it ensures that input will be entirely consumed, and output will always contain the result, reducing intermediate buffering.
 * **************************************************/
 
 
 typedef ZSTD_DStream ZBUFF_DCtx;
 ZBUFF_DEPRECATED("use ZSTD_createDStream") ZBUFF_DCtx* ZBUFF_createDCtx(void);
 ZBUFF_DEPRECATED("use ZSTD_freeDStream")   size_t      ZBUFF_freeDCtx(ZBUFF_DCtx* dctx);
 
 ZBUFF_DEPRECATED("use ZSTD_initDStream")           size_t ZBUFF_decompressInit(ZBUFF_DCtx* dctx);
 ZBUFF_DEPRECATED("use ZSTD_initDStream_usingDict") size_t ZBUFF_decompressInitDictionary(ZBUFF_DCtx* dctx, const void* dict, size_t dictSize);
 
 ZBUFF_DEPRECATED("use ZSTD_decompressStream") size_t ZBUFF_decompressContinue(ZBUFF_DCtx* dctx,
                                             void* dst, size_t* dstCapacityPtr,
                                       const void* src, size_t* srcSizePtr);
 
 /*-***************************************************************************
 *  Streaming decompression howto
 *
 *  A ZBUFF_DCtx object is required to track streaming operations.
 *  Use ZBUFF_createDCtx() and ZBUFF_freeDCtx() to create/release resources.
 *  Use ZBUFF_decompressInit() to start a new decompression operation,
 *   or ZBUFF_decompressInitDictionary() if decompression requires a dictionary.
 *  Note that ZBUFF_DCtx objects can be re-init multiple times.
 *
 *  Use ZBUFF_decompressContinue() repetitively to consume your input.
 *  *srcSizePtr and *dstCapacityPtr can be any size.
 *  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
 *  Note that it may not consume the entire input, in which case it's up to the caller to present remaining input again.
 *  The content of `dst` will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters, or change `dst`.
 *  @return : 0 when a frame is completely decoded and fully flushed,
 *            1 when there is still some data left within internal buffer to flush,
 *            >1 when more data is expected, with value being a suggested next input size (it's just a hint, which helps latency),
 *            or an error code, which can be tested using ZBUFF_isError().
 *
 *  Hint : recommended buffer sizes (not compulsory) : ZBUFF_recommendedDInSize() and ZBUFF_recommendedDOutSize()
 *  output : ZBUFF_recommendedDOutSize== 128 KB block size is the internal unit, it ensures it's always possible to write a full block when decoded.
 *  input  : ZBUFF_recommendedDInSize == 128KB + 3;
 *           just follow indications from ZBUFF_decompressContinue() to minimize latency. It should always be <= 128 KB + 3 .
 * *******************************************************************************/
 
 
 /* *************************************
 *  Tool functions
 ***************************************/
 ZBUFF_DEPRECATED("use ZSTD_isError")      unsigned ZBUFF_isError(size_t errorCode);
 ZBUFF_DEPRECATED("use ZSTD_getErrorName") const char* ZBUFF_getErrorName(size_t errorCode);
 
 /** Functions below provide recommended buffer sizes for Compression or Decompression operations.
 *   These sizes are just hints, they tend to offer better latency */
 ZBUFF_DEPRECATED("use ZSTD_CStreamInSize")  size_t ZBUFF_recommendedCInSize(void);
 ZBUFF_DEPRECATED("use ZSTD_CStreamOutSize") size_t ZBUFF_recommendedCOutSize(void);
 ZBUFF_DEPRECATED("use ZSTD_DStreamInSize")  size_t ZBUFF_recommendedDInSize(void);
 ZBUFF_DEPRECATED("use ZSTD_DStreamOutSize") size_t ZBUFF_recommendedDOutSize(void);
 
 #endif  /* ZSTD_BUFFERED_H_23987 */
 
 
 #ifdef ZBUFF_STATIC_LINKING_ONLY
 #ifndef ZBUFF_STATIC_H_30298098432
 #define ZBUFF_STATIC_H_30298098432
 
 /* ====================================================================================
  * The definitions in this section are considered experimental.
  * They should never be used in association with a dynamic library, as they may change in the future.
  * They are provided for advanced usages.
  * Use them only in association with static linking.
  * ==================================================================================== */
 
 /*--- Dependency ---*/
 #define ZSTD_STATIC_LINKING_ONLY   /* ZSTD_parameters, ZSTD_customMem */
 #include "zstd.h"
 
 
 /*--- Custom memory allocator ---*/
 /*! ZBUFF_createCCtx_advanced() :
  *  Create a ZBUFF compression context using external alloc and free functions */
 ZBUFF_DEPRECATED("use ZSTD_createCStream_advanced") ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem);
 
 /*! ZBUFF_createDCtx_advanced() :
  *  Create a ZBUFF decompression context using external alloc and free functions */
 ZBUFF_DEPRECATED("use ZSTD_createDStream_advanced") ZBUFF_DCtx* ZBUFF_createDCtx_advanced(ZSTD_customMem customMem);
 
 
 /*--- Advanced Streaming Initialization ---*/
 ZBUFF_DEPRECATED("use ZSTD_initDStream_usingDict") size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,
                                                const void* dict, size_t dictSize,
                                                ZSTD_parameters params, unsigned long long pledgedSrcSize);
 
 
 #endif    /* ZBUFF_STATIC_H_30298098432 */
 #endif    /* ZBUFF_STATIC_LINKING_ONLY */
 
 
 #if defined (__cplusplus)
 }
 #endif
Index: head/sys/contrib/zstd/lib/dictBuilder/cover.c
===================================================================
--- head/sys/contrib/zstd/lib/dictBuilder/cover.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/dictBuilder/cover.c	(revision 354777)
@@ -1,1237 +1,1236 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 /* *****************************************************************************
  * Constructs a dictionary using a heuristic based on the following paper:
  *
  * Liao, Petri, Moffat, Wirth
  * Effective Construction of Relative Lempel-Ziv Dictionaries
  * Published in WWW 2016.
  *
  * Adapted from code originally written by @ot (Giuseppe Ottaviano).
  ******************************************************************************/
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include   /* fprintf */
 #include  /* malloc, free, qsort */
 #include  /* memset */
 #include    /* clock */
 
 #include "mem.h" /* read */
 #include "pool.h"
 #include "threading.h"
 #include "cover.h"
 #include "zstd_internal.h" /* includes zstd.h */
 #ifndef ZDICT_STATIC_LINKING_ONLY
 #define ZDICT_STATIC_LINKING_ONLY
 #endif
 #include "zdict.h"
 
 /*-*************************************
 *  Constants
 ***************************************/
 #define COVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((unsigned)-1) : ((unsigned)1 GB))
 #define DEFAULT_SPLITPOINT 1.0
 
 /*-*************************************
 *  Console display
 ***************************************/
 static int g_displayLevel = 2;
 #define DISPLAY(...)                                                           \
   {                                                                            \
     fprintf(stderr, __VA_ARGS__);                                              \
     fflush(stderr);                                                            \
   }
 #define LOCALDISPLAYLEVEL(displayLevel, l, ...)                                \
   if (displayLevel >= l) {                                                     \
     DISPLAY(__VA_ARGS__);                                                      \
   } /* 0 : no display;   1: errors;   2: default;  3: details;  4: debug */
 #define DISPLAYLEVEL(l, ...) LOCALDISPLAYLEVEL(g_displayLevel, l, __VA_ARGS__)
 
 #define LOCALDISPLAYUPDATE(displayLevel, l, ...)                               \
   if (displayLevel >= l) {                                                     \
     if ((clock() - g_time > refreshRate) || (displayLevel >= 4)) {             \
       g_time = clock();                                                        \
       DISPLAY(__VA_ARGS__);                                                    \
     }                                                                          \
   }
 #define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__)
 static const clock_t refreshRate = CLOCKS_PER_SEC * 15 / 100;
 static clock_t g_time = 0;
 
 /*-*************************************
 * Hash table
 ***************************************
 * A small specialized hash map for storing activeDmers.
 * The map does not resize, so if it becomes full it will loop forever.
 * Thus, the map must be large enough to store every value.
 * The map implements linear probing and keeps its load less than 0.5.
 */
 
 #define MAP_EMPTY_VALUE ((U32)-1)
 typedef struct COVER_map_pair_t_s {
   U32 key;
   U32 value;
 } COVER_map_pair_t;
 
 typedef struct COVER_map_s {
   COVER_map_pair_t *data;
   U32 sizeLog;
   U32 size;
   U32 sizeMask;
 } COVER_map_t;
 
 /**
  * Clear the map.
  */
 static void COVER_map_clear(COVER_map_t *map) {
   memset(map->data, MAP_EMPTY_VALUE, map->size * sizeof(COVER_map_pair_t));
 }
 
 /**
  * Initializes a map of the given size.
  * Returns 1 on success and 0 on failure.
  * The map must be destroyed with COVER_map_destroy().
  * The map is only guaranteed to be large enough to hold size elements.
  */
 static int COVER_map_init(COVER_map_t *map, U32 size) {
   map->sizeLog = ZSTD_highbit32(size) + 2;
   map->size = (U32)1 << map->sizeLog;
   map->sizeMask = map->size - 1;
   map->data = (COVER_map_pair_t *)malloc(map->size * sizeof(COVER_map_pair_t));
   if (!map->data) {
     map->sizeLog = 0;
     map->size = 0;
     return 0;
   }
   COVER_map_clear(map);
   return 1;
 }
 
 /**
  * Internal hash function
  */
 static const U32 prime4bytes = 2654435761U;
 static U32 COVER_map_hash(COVER_map_t *map, U32 key) {
   return (key * prime4bytes) >> (32 - map->sizeLog);
 }
 
 /**
  * Helper function that returns the index that a key should be placed into.
  */
 static U32 COVER_map_index(COVER_map_t *map, U32 key) {
   const U32 hash = COVER_map_hash(map, key);
   U32 i;
   for (i = hash;; i = (i + 1) & map->sizeMask) {
     COVER_map_pair_t *pos = &map->data[i];
     if (pos->value == MAP_EMPTY_VALUE) {
       return i;
     }
     if (pos->key == key) {
       return i;
     }
   }
 }
 
 /**
  * Returns the pointer to the value for key.
  * If key is not in the map, it is inserted and the value is set to 0.
  * The map must not be full.
  */
 static U32 *COVER_map_at(COVER_map_t *map, U32 key) {
   COVER_map_pair_t *pos = &map->data[COVER_map_index(map, key)];
   if (pos->value == MAP_EMPTY_VALUE) {
     pos->key = key;
     pos->value = 0;
   }
   return &pos->value;
 }
 
 /**
  * Deletes key from the map if present.
  */
 static void COVER_map_remove(COVER_map_t *map, U32 key) {
   U32 i = COVER_map_index(map, key);
   COVER_map_pair_t *del = &map->data[i];
   U32 shift = 1;
   if (del->value == MAP_EMPTY_VALUE) {
     return;
   }
   for (i = (i + 1) & map->sizeMask;; i = (i + 1) & map->sizeMask) {
     COVER_map_pair_t *const pos = &map->data[i];
     /* If the position is empty we are done */
     if (pos->value == MAP_EMPTY_VALUE) {
       del->value = MAP_EMPTY_VALUE;
       return;
     }
     /* If pos can be moved to del do so */
     if (((i - COVER_map_hash(map, pos->key)) & map->sizeMask) >= shift) {
       del->key = pos->key;
       del->value = pos->value;
       del = pos;
       shift = 1;
     } else {
       ++shift;
     }
   }
 }
 
 /**
  * Destroys a map that is inited with COVER_map_init().
  */
 static void COVER_map_destroy(COVER_map_t *map) {
   if (map->data) {
     free(map->data);
   }
   map->data = NULL;
   map->size = 0;
 }
 
 /*-*************************************
 * Context
 ***************************************/
 
 typedef struct {
   const BYTE *samples;
   size_t *offsets;
   const size_t *samplesSizes;
   size_t nbSamples;
   size_t nbTrainSamples;
   size_t nbTestSamples;
   U32 *suffix;
   size_t suffixSize;
   U32 *freqs;
   U32 *dmerAt;
   unsigned d;
 } COVER_ctx_t;
 
 /* We need a global context for qsort... */
 static COVER_ctx_t *g_ctx = NULL;
 
 /*-*************************************
 *  Helper functions
 ***************************************/
 
 /**
  * Returns the sum of the sample sizes.
  */
 size_t COVER_sum(const size_t *samplesSizes, unsigned nbSamples) {
   size_t sum = 0;
   unsigned i;
   for (i = 0; i < nbSamples; ++i) {
     sum += samplesSizes[i];
   }
   return sum;
 }
 
 /**
  * Returns -1 if the dmer at lp is less than the dmer at rp.
  * Return 0 if the dmers at lp and rp are equal.
  * Returns 1 if the dmer at lp is greater than the dmer at rp.
  */
 static int COVER_cmp(COVER_ctx_t *ctx, const void *lp, const void *rp) {
   U32 const lhs = *(U32 const *)lp;
   U32 const rhs = *(U32 const *)rp;
   return memcmp(ctx->samples + lhs, ctx->samples + rhs, ctx->d);
 }
 /**
  * Faster version for d <= 8.
  */
 static int COVER_cmp8(COVER_ctx_t *ctx, const void *lp, const void *rp) {
   U64 const mask = (ctx->d == 8) ? (U64)-1 : (((U64)1 << (8 * ctx->d)) - 1);
   U64 const lhs = MEM_readLE64(ctx->samples + *(U32 const *)lp) & mask;
   U64 const rhs = MEM_readLE64(ctx->samples + *(U32 const *)rp) & mask;
   if (lhs < rhs) {
     return -1;
   }
   return (lhs > rhs);
 }
 
 /**
  * Same as COVER_cmp() except ties are broken by pointer value
  * NOTE: g_ctx must be set to call this function.  A global is required because
  * qsort doesn't take an opaque pointer.
  */
 static int COVER_strict_cmp(const void *lp, const void *rp) {
   int result = COVER_cmp(g_ctx, lp, rp);
   if (result == 0) {
     result = lp < rp ? -1 : 1;
   }
   return result;
 }
 /**
  * Faster version for d <= 8.
  */
 static int COVER_strict_cmp8(const void *lp, const void *rp) {
   int result = COVER_cmp8(g_ctx, lp, rp);
   if (result == 0) {
     result = lp < rp ? -1 : 1;
   }
   return result;
 }
 
 /**
  * Returns the first pointer in [first, last) whose element does not compare
  * less than value.  If no such element exists it returns last.
  */
 static const size_t *COVER_lower_bound(const size_t *first, const size_t *last,
                                        size_t value) {
   size_t count = last - first;
   while (count != 0) {
     size_t step = count / 2;
     const size_t *ptr = first;
     ptr += step;
     if (*ptr < value) {
       first = ++ptr;
       count -= step + 1;
     } else {
       count = step;
     }
   }
   return first;
 }
 
 /**
  * Generic groupBy function.
  * Groups an array sorted by cmp into groups with equivalent values.
  * Calls grp for each group.
  */
 static void
 COVER_groupBy(const void *data, size_t count, size_t size, COVER_ctx_t *ctx,
               int (*cmp)(COVER_ctx_t *, const void *, const void *),
               void (*grp)(COVER_ctx_t *, const void *, const void *)) {
   const BYTE *ptr = (const BYTE *)data;
   size_t num = 0;
   while (num < count) {
     const BYTE *grpEnd = ptr + size;
     ++num;
     while (num < count && cmp(ctx, ptr, grpEnd) == 0) {
       grpEnd += size;
       ++num;
     }
     grp(ctx, ptr, grpEnd);
     ptr = grpEnd;
   }
 }
 
 /*-*************************************
 *  Cover functions
 ***************************************/
 
 /**
  * Called on each group of positions with the same dmer.
  * Counts the frequency of each dmer and saves it in the suffix array.
  * Fills `ctx->dmerAt`.
  */
 static void COVER_group(COVER_ctx_t *ctx, const void *group,
                         const void *groupEnd) {
   /* The group consists of all the positions with the same first d bytes. */
   const U32 *grpPtr = (const U32 *)group;
   const U32 *grpEnd = (const U32 *)groupEnd;
   /* The dmerId is how we will reference this dmer.
    * This allows us to map the whole dmer space to a much smaller space, the
    * size of the suffix array.
    */
   const U32 dmerId = (U32)(grpPtr - ctx->suffix);
   /* Count the number of samples this dmer shows up in */
   U32 freq = 0;
   /* Details */
   const size_t *curOffsetPtr = ctx->offsets;
   const size_t *offsetsEnd = ctx->offsets + ctx->nbSamples;
   /* Once *grpPtr >= curSampleEnd this occurrence of the dmer is in a
    * different sample than the last.
    */
   size_t curSampleEnd = ctx->offsets[0];
   for (; grpPtr != grpEnd; ++grpPtr) {
     /* Save the dmerId for this position so we can get back to it. */
     ctx->dmerAt[*grpPtr] = dmerId;
     /* Dictionaries only help for the first reference to the dmer.
      * After that zstd can reference the match from the previous reference.
      * So only count each dmer once for each sample it is in.
      */
     if (*grpPtr < curSampleEnd) {
       continue;
     }
     freq += 1;
     /* Binary search to find the end of the sample *grpPtr is in.
      * In the common case that grpPtr + 1 == grpEnd we can skip the binary
      * search because the loop is over.
      */
     if (grpPtr + 1 != grpEnd) {
       const size_t *sampleEndPtr =
           COVER_lower_bound(curOffsetPtr, offsetsEnd, *grpPtr);
       curSampleEnd = *sampleEndPtr;
       curOffsetPtr = sampleEndPtr + 1;
     }
   }
   /* At this point we are never going to look at this segment of the suffix
    * array again.  We take advantage of this fact to save memory.
    * We store the frequency of the dmer in the first position of the group,
    * which is dmerId.
    */
   ctx->suffix[dmerId] = freq;
 }
 
 
 /**
  * Selects the best segment in an epoch.
  * Segments of are scored according to the function:
  *
  * Let F(d) be the frequency of dmer d.
  * Let S_i be the dmer at position i of segment S which has length k.
  *
  *     Score(S) = F(S_1) + F(S_2) + ... + F(S_{k-d+1})
  *
  * Once the dmer d is in the dictionary we set F(d) = 0.
  */
 static COVER_segment_t COVER_selectSegment(const COVER_ctx_t *ctx, U32 *freqs,
                                            COVER_map_t *activeDmers, U32 begin,
                                            U32 end,
                                            ZDICT_cover_params_t parameters) {
   /* Constants */
   const U32 k = parameters.k;
   const U32 d = parameters.d;
   const U32 dmersInK = k - d + 1;
   /* Try each segment (activeSegment) and save the best (bestSegment) */
   COVER_segment_t bestSegment = {0, 0, 0};
   COVER_segment_t activeSegment;
   /* Reset the activeDmers in the segment */
   COVER_map_clear(activeDmers);
   /* The activeSegment starts at the beginning of the epoch. */
   activeSegment.begin = begin;
   activeSegment.end = begin;
   activeSegment.score = 0;
   /* Slide the activeSegment through the whole epoch.
    * Save the best segment in bestSegment.
    */
   while (activeSegment.end < end) {
     /* The dmerId for the dmer at the next position */
     U32 newDmer = ctx->dmerAt[activeSegment.end];
     /* The entry in activeDmers for this dmerId */
     U32 *newDmerOcc = COVER_map_at(activeDmers, newDmer);
     /* If the dmer isn't already present in the segment add its score. */
     if (*newDmerOcc == 0) {
       /* The paper suggest using the L-0.5 norm, but experiments show that it
        * doesn't help.
        */
       activeSegment.score += freqs[newDmer];
     }
     /* Add the dmer to the segment */
     activeSegment.end += 1;
     *newDmerOcc += 1;
 
     /* If the window is now too large, drop the first position */
     if (activeSegment.end - activeSegment.begin == dmersInK + 1) {
       U32 delDmer = ctx->dmerAt[activeSegment.begin];
       U32 *delDmerOcc = COVER_map_at(activeDmers, delDmer);
       activeSegment.begin += 1;
       *delDmerOcc -= 1;
       /* If this is the last occurrence of the dmer, subtract its score */
       if (*delDmerOcc == 0) {
         COVER_map_remove(activeDmers, delDmer);
         activeSegment.score -= freqs[delDmer];
       }
     }
 
     /* If this segment is the best so far save it */
     if (activeSegment.score > bestSegment.score) {
       bestSegment = activeSegment;
     }
   }
   {
     /* Trim off the zero frequency head and tail from the segment. */
     U32 newBegin = bestSegment.end;
     U32 newEnd = bestSegment.begin;
     U32 pos;
     for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
       U32 freq = freqs[ctx->dmerAt[pos]];
       if (freq != 0) {
         newBegin = MIN(newBegin, pos);
         newEnd = pos + 1;
       }
     }
     bestSegment.begin = newBegin;
     bestSegment.end = newEnd;
   }
   {
     /* Zero out the frequency of each dmer covered by the chosen segment. */
     U32 pos;
     for (pos = bestSegment.begin; pos != bestSegment.end; ++pos) {
       freqs[ctx->dmerAt[pos]] = 0;
     }
   }
   return bestSegment;
 }
 
 /**
  * Check the validity of the parameters.
  * Returns non-zero if the parameters are valid and 0 otherwise.
  */
 static int COVER_checkParameters(ZDICT_cover_params_t parameters,
                                  size_t maxDictSize) {
   /* k and d are required parameters */
   if (parameters.d == 0 || parameters.k == 0) {
     return 0;
   }
   /* k <= maxDictSize */
   if (parameters.k > maxDictSize) {
     return 0;
   }
   /* d <= k */
   if (parameters.d > parameters.k) {
     return 0;
   }
   /* 0 < splitPoint <= 1 */
   if (parameters.splitPoint <= 0 || parameters.splitPoint > 1){
     return 0;
   }
   return 1;
 }
 
 /**
  * Clean up a context initialized with `COVER_ctx_init()`.
  */
 static void COVER_ctx_destroy(COVER_ctx_t *ctx) {
   if (!ctx) {
     return;
   }
   if (ctx->suffix) {
     free(ctx->suffix);
     ctx->suffix = NULL;
   }
   if (ctx->freqs) {
     free(ctx->freqs);
     ctx->freqs = NULL;
   }
   if (ctx->dmerAt) {
     free(ctx->dmerAt);
     ctx->dmerAt = NULL;
   }
   if (ctx->offsets) {
     free(ctx->offsets);
     ctx->offsets = NULL;
   }
 }
 
 /**
  * Prepare a context for dictionary building.
  * The context is only dependent on the parameter `d` and can used multiple
  * times.
  * Returns 0 on success or error code on error.
  * The context must be destroyed with `COVER_ctx_destroy()`.
  */
 static size_t COVER_ctx_init(COVER_ctx_t *ctx, const void *samplesBuffer,
                           const size_t *samplesSizes, unsigned nbSamples,
                           unsigned d, double splitPoint) {
   const BYTE *const samples = (const BYTE *)samplesBuffer;
   const size_t totalSamplesSize = COVER_sum(samplesSizes, nbSamples);
   /* Split samples into testing and training sets */
   const unsigned nbTrainSamples = splitPoint < 1.0 ? (unsigned)((double)nbSamples * splitPoint) : nbSamples;
   const unsigned nbTestSamples = splitPoint < 1.0 ? nbSamples - nbTrainSamples : nbSamples;
   const size_t trainingSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes, nbTrainSamples) : totalSamplesSize;
   const size_t testSamplesSize = splitPoint < 1.0 ? COVER_sum(samplesSizes + nbTrainSamples, nbTestSamples) : totalSamplesSize;
   /* Checks */
   if (totalSamplesSize < MAX(d, sizeof(U64)) ||
       totalSamplesSize >= (size_t)COVER_MAX_SAMPLES_SIZE) {
     DISPLAYLEVEL(1, "Total samples size is too large (%u MB), maximum size is %u MB\n",
                  (unsigned)(totalSamplesSize>>20), (COVER_MAX_SAMPLES_SIZE >> 20));
     return ERROR(srcSize_wrong);
   }
   /* Check if there are at least 5 training samples */
   if (nbTrainSamples < 5) {
     DISPLAYLEVEL(1, "Total number of training samples is %u and is invalid.", nbTrainSamples);
     return ERROR(srcSize_wrong);
   }
   /* Check if there's testing sample */
   if (nbTestSamples < 1) {
     DISPLAYLEVEL(1, "Total number of testing samples is %u and is invalid.", nbTestSamples);
     return ERROR(srcSize_wrong);
   }
   /* Zero the context */
   memset(ctx, 0, sizeof(*ctx));
   DISPLAYLEVEL(2, "Training on %u samples of total size %u\n", nbTrainSamples,
                (unsigned)trainingSamplesSize);
   DISPLAYLEVEL(2, "Testing on %u samples of total size %u\n", nbTestSamples,
                (unsigned)testSamplesSize);
   ctx->samples = samples;
   ctx->samplesSizes = samplesSizes;
   ctx->nbSamples = nbSamples;
   ctx->nbTrainSamples = nbTrainSamples;
   ctx->nbTestSamples = nbTestSamples;
   /* Partial suffix array */
   ctx->suffixSize = trainingSamplesSize - MAX(d, sizeof(U64)) + 1;
   ctx->suffix = (U32 *)malloc(ctx->suffixSize * sizeof(U32));
   /* Maps index to the dmerID */
   ctx->dmerAt = (U32 *)malloc(ctx->suffixSize * sizeof(U32));
   /* The offsets of each file */
   ctx->offsets = (size_t *)malloc((nbSamples + 1) * sizeof(size_t));
   if (!ctx->suffix || !ctx->dmerAt || !ctx->offsets) {
     DISPLAYLEVEL(1, "Failed to allocate scratch buffers\n");
     COVER_ctx_destroy(ctx);
     return ERROR(memory_allocation);
   }
   ctx->freqs = NULL;
   ctx->d = d;
 
   /* Fill offsets from the samplesSizes */
   {
     U32 i;
     ctx->offsets[0] = 0;
     for (i = 1; i <= nbSamples; ++i) {
       ctx->offsets[i] = ctx->offsets[i - 1] + samplesSizes[i - 1];
     }
   }
   DISPLAYLEVEL(2, "Constructing partial suffix array\n");
   {
     /* suffix is a partial suffix array.
      * It only sorts suffixes by their first parameters.d bytes.
      * The sort is stable, so each dmer group is sorted by position in input.
      */
     U32 i;
     for (i = 0; i < ctx->suffixSize; ++i) {
       ctx->suffix[i] = i;
     }
     /* qsort doesn't take an opaque pointer, so pass as a global.
      * On OpenBSD qsort() is not guaranteed to be stable, their mergesort() is.
      */
     g_ctx = ctx;
 #if defined(__OpenBSD__)
     mergesort(ctx->suffix, ctx->suffixSize, sizeof(U32),
           (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
 #else
     qsort(ctx->suffix, ctx->suffixSize, sizeof(U32),
           (ctx->d <= 8 ? &COVER_strict_cmp8 : &COVER_strict_cmp));
 #endif
   }
   DISPLAYLEVEL(2, "Computing frequencies\n");
   /* For each dmer group (group of positions with the same first d bytes):
    * 1. For each position we set dmerAt[position] = dmerID.  The dmerID is
    *    (groupBeginPtr - suffix).  This allows us to go from position to
    *    dmerID so we can look up values in freq.
    * 2. We calculate how many samples the dmer occurs in and save it in
    *    freqs[dmerId].
    */
   COVER_groupBy(ctx->suffix, ctx->suffixSize, sizeof(U32), ctx,
                 (ctx->d <= 8 ? &COVER_cmp8 : &COVER_cmp), &COVER_group);
   ctx->freqs = ctx->suffix;
   ctx->suffix = NULL;
   return 0;
 }
 
 void COVER_warnOnSmallCorpus(size_t maxDictSize, size_t nbDmers, int displayLevel)
 {
   const double ratio = (double)nbDmers / maxDictSize;
   if (ratio >= 10) {
       return;
   }
   LOCALDISPLAYLEVEL(displayLevel, 1,
                     "WARNING: The maximum dictionary size %u is too large "
                     "compared to the source size %u! "
                     "size(source)/size(dictionary) = %f, but it should be >= "
                     "10! This may lead to a subpar dictionary! We recommend "
-                    "training on sources at least 10x, and up to 100x the "
-                    "size of the dictionary!\n", (U32)maxDictSize,
+                    "training on sources at least 10x, and preferably 100x "
+                    "the size of the dictionary! \n", (U32)maxDictSize,
                     (U32)nbDmers, ratio);
 }
 
 COVER_epoch_info_t COVER_computeEpochs(U32 maxDictSize,
                                        U32 nbDmers, U32 k, U32 passes)
 {
   const U32 minEpochSize = k * 10;
   COVER_epoch_info_t epochs;
   epochs.num = MAX(1, maxDictSize / k / passes);
   epochs.size = nbDmers / epochs.num;
   if (epochs.size >= minEpochSize) {
       assert(epochs.size * epochs.num <= nbDmers);
       return epochs;
   }
   epochs.size = MIN(minEpochSize, nbDmers);
   epochs.num = nbDmers / epochs.size;
   assert(epochs.size * epochs.num <= nbDmers);
   return epochs;
 }
 
 /**
  * Given the prepared context build the dictionary.
  */
 static size_t COVER_buildDictionary(const COVER_ctx_t *ctx, U32 *freqs,
                                     COVER_map_t *activeDmers, void *dictBuffer,
                                     size_t dictBufferCapacity,
                                     ZDICT_cover_params_t parameters) {
   BYTE *const dict = (BYTE *)dictBuffer;
   size_t tail = dictBufferCapacity;
   /* Divide the data into epochs. We will select one segment from each epoch. */
   const COVER_epoch_info_t epochs = COVER_computeEpochs(
       (U32)dictBufferCapacity, (U32)ctx->suffixSize, parameters.k, 4);
   const size_t maxZeroScoreRun = MAX(10, MIN(100, epochs.num >> 3));
   size_t zeroScoreRun = 0;
   size_t epoch;
   DISPLAYLEVEL(2, "Breaking content into %u epochs of size %u\n",
                 (U32)epochs.num, (U32)epochs.size);
   /* Loop through the epochs until there are no more segments or the dictionary
    * is full.
    */
   for (epoch = 0; tail > 0; epoch = (epoch + 1) % epochs.num) {
     const U32 epochBegin = (U32)(epoch * epochs.size);
     const U32 epochEnd = epochBegin + epochs.size;
     size_t segmentSize;
     /* Select a segment */
     COVER_segment_t segment = COVER_selectSegment(
         ctx, freqs, activeDmers, epochBegin, epochEnd, parameters);
     /* If the segment covers no dmers, then we are out of content.
      * There may be new content in other epochs, for continue for some time.
      */
     if (segment.score == 0) {
       if (++zeroScoreRun >= maxZeroScoreRun) {
           break;
       }
       continue;
     }
     zeroScoreRun = 0;
     /* Trim the segment if necessary and if it is too small then we are done */
     segmentSize = MIN(segment.end - segment.begin + parameters.d - 1, tail);
     if (segmentSize < parameters.d) {
       break;
     }
     /* We fill the dictionary from the back to allow the best segments to be
      * referenced with the smallest offsets.
      */
     tail -= segmentSize;
     memcpy(dict + tail, ctx->samples + segment.begin, segmentSize);
     DISPLAYUPDATE(
         2, "\r%u%%       ",
         (unsigned)(((dictBufferCapacity - tail) * 100) / dictBufferCapacity));
   }
   DISPLAYLEVEL(2, "\r%79s\r", "");
   return tail;
 }
 
 ZDICTLIB_API size_t ZDICT_trainFromBuffer_cover(
     void *dictBuffer, size_t dictBufferCapacity,
     const void *samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
     ZDICT_cover_params_t parameters)
 {
   BYTE* const dict = (BYTE*)dictBuffer;
   COVER_ctx_t ctx;
   COVER_map_t activeDmers;
   parameters.splitPoint = 1.0;
   /* Initialize global data */
   g_displayLevel = parameters.zParams.notificationLevel;
   /* Checks */
   if (!COVER_checkParameters(parameters, dictBufferCapacity)) {
     DISPLAYLEVEL(1, "Cover parameters incorrect\n");
     return ERROR(parameter_outOfBound);
   }
   if (nbSamples == 0) {
     DISPLAYLEVEL(1, "Cover must have at least one input file\n");
     return ERROR(srcSize_wrong);
   }
   if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
     DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n",
                  ZDICT_DICTSIZE_MIN);
     return ERROR(dstSize_tooSmall);
   }
   /* Initialize context and activeDmers */
   {
     size_t const initVal = COVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples,
                       parameters.d, parameters.splitPoint);
     if (ZSTD_isError(initVal)) {
       return initVal;
     }
   }
   COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.suffixSize, g_displayLevel);
   if (!COVER_map_init(&activeDmers, parameters.k - parameters.d + 1)) {
     DISPLAYLEVEL(1, "Failed to allocate dmer map: out of memory\n");
     COVER_ctx_destroy(&ctx);
     return ERROR(memory_allocation);
   }
 
   DISPLAYLEVEL(2, "Building dictionary\n");
   {
     const size_t tail =
         COVER_buildDictionary(&ctx, ctx.freqs, &activeDmers, dictBuffer,
                               dictBufferCapacity, parameters);
     const size_t dictionarySize = ZDICT_finalizeDictionary(
         dict, dictBufferCapacity, dict + tail, dictBufferCapacity - tail,
         samplesBuffer, samplesSizes, nbSamples, parameters.zParams);
     if (!ZSTD_isError(dictionarySize)) {
       DISPLAYLEVEL(2, "Constructed dictionary of size %u\n",
                    (unsigned)dictionarySize);
     }
     COVER_ctx_destroy(&ctx);
     COVER_map_destroy(&activeDmers);
     return dictionarySize;
   }
 }
 
 
 
 size_t COVER_checkTotalCompressedSize(const ZDICT_cover_params_t parameters,
                                     const size_t *samplesSizes, const BYTE *samples,
                                     size_t *offsets,
                                     size_t nbTrainSamples, size_t nbSamples,
                                     BYTE *const dict, size_t dictBufferCapacity) {
   size_t totalCompressedSize = ERROR(GENERIC);
   /* Pointers */
   ZSTD_CCtx *cctx;
   ZSTD_CDict *cdict;
   void *dst;
   /* Local variables */
   size_t dstCapacity;
   size_t i;
   /* Allocate dst with enough space to compress the maximum sized sample */
   {
     size_t maxSampleSize = 0;
     i = parameters.splitPoint < 1.0 ? nbTrainSamples : 0;
     for (; i < nbSamples; ++i) {
       maxSampleSize = MAX(samplesSizes[i], maxSampleSize);
     }
     dstCapacity = ZSTD_compressBound(maxSampleSize);
     dst = malloc(dstCapacity);
   }
   /* Create the cctx and cdict */
   cctx = ZSTD_createCCtx();
   cdict = ZSTD_createCDict(dict, dictBufferCapacity,
                            parameters.zParams.compressionLevel);
   if (!dst || !cctx || !cdict) {
     goto _compressCleanup;
   }
   /* Compress each sample and sum their sizes (or error) */
   totalCompressedSize = dictBufferCapacity;
   i = parameters.splitPoint < 1.0 ? nbTrainSamples : 0;
   for (; i < nbSamples; ++i) {
     const size_t size = ZSTD_compress_usingCDict(
         cctx, dst, dstCapacity, samples + offsets[i],
         samplesSizes[i], cdict);
     if (ZSTD_isError(size)) {
       totalCompressedSize = size;
       goto _compressCleanup;
     }
     totalCompressedSize += size;
   }
 _compressCleanup:
   ZSTD_freeCCtx(cctx);
   ZSTD_freeCDict(cdict);
   if (dst) {
     free(dst);
   }
   return totalCompressedSize;
 }
 
 
 /**
  * Initialize the `COVER_best_t`.
  */
 void COVER_best_init(COVER_best_t *best) {
   if (best==NULL) return; /* compatible with init on NULL */
   (void)ZSTD_pthread_mutex_init(&best->mutex, NULL);
   (void)ZSTD_pthread_cond_init(&best->cond, NULL);
   best->liveJobs = 0;
   best->dict = NULL;
   best->dictSize = 0;
   best->compressedSize = (size_t)-1;
   memset(&best->parameters, 0, sizeof(best->parameters));
 }
 
 /**
  * Wait until liveJobs == 0.
  */
 void COVER_best_wait(COVER_best_t *best) {
   if (!best) {
     return;
   }
   ZSTD_pthread_mutex_lock(&best->mutex);
   while (best->liveJobs != 0) {
     ZSTD_pthread_cond_wait(&best->cond, &best->mutex);
   }
   ZSTD_pthread_mutex_unlock(&best->mutex);
 }
 
 /**
  * Call COVER_best_wait() and then destroy the COVER_best_t.
  */
 void COVER_best_destroy(COVER_best_t *best) {
   if (!best) {
     return;
   }
   COVER_best_wait(best);
   if (best->dict) {
     free(best->dict);
   }
   ZSTD_pthread_mutex_destroy(&best->mutex);
   ZSTD_pthread_cond_destroy(&best->cond);
 }
 
 /**
  * Called when a thread is about to be launched.
  * Increments liveJobs.
  */
 void COVER_best_start(COVER_best_t *best) {
   if (!best) {
     return;
   }
   ZSTD_pthread_mutex_lock(&best->mutex);
   ++best->liveJobs;
   ZSTD_pthread_mutex_unlock(&best->mutex);
 }
 
 /**
  * Called when a thread finishes executing, both on error or success.
  * Decrements liveJobs and signals any waiting threads if liveJobs == 0.
  * If this dictionary is the best so far save it and its parameters.
  */
 void COVER_best_finish(COVER_best_t *best, ZDICT_cover_params_t parameters,
                               COVER_dictSelection_t selection) {
   void* dict = selection.dictContent;
   size_t compressedSize = selection.totalCompressedSize;
   size_t dictSize = selection.dictSize;
   if (!best) {
     return;
   }
   {
     size_t liveJobs;
     ZSTD_pthread_mutex_lock(&best->mutex);
     --best->liveJobs;
     liveJobs = best->liveJobs;
     /* If the new dictionary is better */
     if (compressedSize < best->compressedSize) {
       /* Allocate space if necessary */
       if (!best->dict || best->dictSize < dictSize) {
         if (best->dict) {
           free(best->dict);
         }
         best->dict = malloc(dictSize);
         if (!best->dict) {
           best->compressedSize = ERROR(GENERIC);
           best->dictSize = 0;
           ZSTD_pthread_cond_signal(&best->cond);
           ZSTD_pthread_mutex_unlock(&best->mutex);
           return;
         }
       }
       /* Save the dictionary, parameters, and size */
-      if (!dict) {
-        return;
+      if (dict) {
+        memcpy(best->dict, dict, dictSize);
+        best->dictSize = dictSize;
+        best->parameters = parameters;
+        best->compressedSize = compressedSize;
       }
-      memcpy(best->dict, dict, dictSize);
-      best->dictSize = dictSize;
-      best->parameters = parameters;
-      best->compressedSize = compressedSize;
     }
     if (liveJobs == 0) {
       ZSTD_pthread_cond_broadcast(&best->cond);
     }
     ZSTD_pthread_mutex_unlock(&best->mutex);
   }
 }
 
 COVER_dictSelection_t COVER_dictSelectionError(size_t error) {
     COVER_dictSelection_t selection = { NULL, 0, error };
     return selection;
 }
 
 unsigned COVER_dictSelectionIsError(COVER_dictSelection_t selection) {
   return (ZSTD_isError(selection.totalCompressedSize) || !selection.dictContent);
 }
 
 void COVER_dictSelectionFree(COVER_dictSelection_t selection){
   free(selection.dictContent);
 }
 
 COVER_dictSelection_t COVER_selectDict(BYTE* customDictContent,
         size_t dictContentSize, const BYTE* samplesBuffer, const size_t* samplesSizes, unsigned nbFinalizeSamples,
         size_t nbCheckSamples, size_t nbSamples, ZDICT_cover_params_t params, size_t* offsets, size_t totalCompressedSize) {
 
   size_t largestDict = 0;
   size_t largestCompressed = 0;
   BYTE* customDictContentEnd = customDictContent + dictContentSize;
 
   BYTE * largestDictbuffer = (BYTE *)malloc(dictContentSize);
   BYTE * candidateDictBuffer = (BYTE *)malloc(dictContentSize);
   double regressionTolerance = ((double)params.shrinkDictMaxRegression / 100.0) + 1.00;
 
   if (!largestDictbuffer || !candidateDictBuffer) {
     free(largestDictbuffer);
     free(candidateDictBuffer);
     return COVER_dictSelectionError(dictContentSize);
   }
 
   /* Initial dictionary size and compressed size */
   memcpy(largestDictbuffer, customDictContent, dictContentSize);
   dictContentSize = ZDICT_finalizeDictionary(
     largestDictbuffer, dictContentSize, customDictContent, dictContentSize,
     samplesBuffer, samplesSizes, nbFinalizeSamples, params.zParams);
 
   if (ZDICT_isError(dictContentSize)) {
     free(largestDictbuffer);
     free(candidateDictBuffer);
     return COVER_dictSelectionError(dictContentSize);
   }
 
   totalCompressedSize = COVER_checkTotalCompressedSize(params, samplesSizes,
                                                        samplesBuffer, offsets,
                                                        nbCheckSamples, nbSamples,
                                                        largestDictbuffer, dictContentSize);
 
   if (ZSTD_isError(totalCompressedSize)) {
     free(largestDictbuffer);
     free(candidateDictBuffer);
     return COVER_dictSelectionError(totalCompressedSize);
   }
 
   if (params.shrinkDict == 0) {
     COVER_dictSelection_t selection = { largestDictbuffer, dictContentSize, totalCompressedSize };
     free(candidateDictBuffer);
     return selection;
   }
 
   largestDict = dictContentSize;
   largestCompressed = totalCompressedSize;
   dictContentSize = ZDICT_DICTSIZE_MIN;
 
   /* Largest dict is initially at least ZDICT_DICTSIZE_MIN */
   while (dictContentSize < largestDict) {
     memcpy(candidateDictBuffer, largestDictbuffer, largestDict);
     dictContentSize = ZDICT_finalizeDictionary(
       candidateDictBuffer, dictContentSize, customDictContentEnd - dictContentSize, dictContentSize,
       samplesBuffer, samplesSizes, nbFinalizeSamples, params.zParams);
 
     if (ZDICT_isError(dictContentSize)) {
       free(largestDictbuffer);
       free(candidateDictBuffer);
       return COVER_dictSelectionError(dictContentSize);
 
     }
 
     totalCompressedSize = COVER_checkTotalCompressedSize(params, samplesSizes,
                                                          samplesBuffer, offsets,
                                                          nbCheckSamples, nbSamples,
                                                          candidateDictBuffer, dictContentSize);
 
     if (ZSTD_isError(totalCompressedSize)) {
       free(largestDictbuffer);
       free(candidateDictBuffer);
       return COVER_dictSelectionError(totalCompressedSize);
     }
 
     if (totalCompressedSize <= largestCompressed * regressionTolerance) {
       COVER_dictSelection_t selection = { candidateDictBuffer, dictContentSize, totalCompressedSize };
       free(largestDictbuffer);
       return selection;
     }
     dictContentSize *= 2;
   }
   dictContentSize = largestDict;
   totalCompressedSize = largestCompressed;
   {
     COVER_dictSelection_t selection = { largestDictbuffer, dictContentSize, totalCompressedSize };
     free(candidateDictBuffer);
     return selection;
   }
 }
 
 /**
  * Parameters for COVER_tryParameters().
  */
 typedef struct COVER_tryParameters_data_s {
   const COVER_ctx_t *ctx;
   COVER_best_t *best;
   size_t dictBufferCapacity;
   ZDICT_cover_params_t parameters;
 } COVER_tryParameters_data_t;
 
 /**
  * Tries a set of parameters and updates the COVER_best_t with the results.
  * This function is thread safe if zstd is compiled with multithreaded support.
  * It takes its parameters as an *OWNING* opaque pointer to support threading.
  */
 static void COVER_tryParameters(void *opaque) {
   /* Save parameters as local variables */
   COVER_tryParameters_data_t *const data = (COVER_tryParameters_data_t *)opaque;
   const COVER_ctx_t *const ctx = data->ctx;
   const ZDICT_cover_params_t parameters = data->parameters;
   size_t dictBufferCapacity = data->dictBufferCapacity;
   size_t totalCompressedSize = ERROR(GENERIC);
   /* Allocate space for hash table, dict, and freqs */
   COVER_map_t activeDmers;
   BYTE *const dict = (BYTE * const)malloc(dictBufferCapacity);
   COVER_dictSelection_t selection = COVER_dictSelectionError(ERROR(GENERIC));
   U32 *freqs = (U32 *)malloc(ctx->suffixSize * sizeof(U32));
   if (!COVER_map_init(&activeDmers, parameters.k - parameters.d + 1)) {
     DISPLAYLEVEL(1, "Failed to allocate dmer map: out of memory\n");
     goto _cleanup;
   }
   if (!dict || !freqs) {
     DISPLAYLEVEL(1, "Failed to allocate buffers: out of memory\n");
     goto _cleanup;
   }
   /* Copy the frequencies because we need to modify them */
   memcpy(freqs, ctx->freqs, ctx->suffixSize * sizeof(U32));
   /* Build the dictionary */
   {
     const size_t tail = COVER_buildDictionary(ctx, freqs, &activeDmers, dict,
                                               dictBufferCapacity, parameters);
     selection = COVER_selectDict(dict + tail, dictBufferCapacity - tail,
         ctx->samples, ctx->samplesSizes, (unsigned)ctx->nbTrainSamples, ctx->nbTrainSamples, ctx->nbSamples, parameters, ctx->offsets,
         totalCompressedSize);
 
     if (COVER_dictSelectionIsError(selection)) {
       DISPLAYLEVEL(1, "Failed to select dictionary\n");
       goto _cleanup;
     }
   }
 _cleanup:
   free(dict);
   COVER_best_finish(data->best, parameters, selection);
   free(data);
   COVER_map_destroy(&activeDmers);
   COVER_dictSelectionFree(selection);
   if (freqs) {
     free(freqs);
   }
 }
 
 ZDICTLIB_API size_t ZDICT_optimizeTrainFromBuffer_cover(
     void *dictBuffer, size_t dictBufferCapacity, const void *samplesBuffer,
     const size_t *samplesSizes, unsigned nbSamples,
     ZDICT_cover_params_t *parameters) {
   /* constants */
   const unsigned nbThreads = parameters->nbThreads;
   const double splitPoint =
       parameters->splitPoint <= 0.0 ? DEFAULT_SPLITPOINT : parameters->splitPoint;
   const unsigned kMinD = parameters->d == 0 ? 6 : parameters->d;
   const unsigned kMaxD = parameters->d == 0 ? 8 : parameters->d;
   const unsigned kMinK = parameters->k == 0 ? 50 : parameters->k;
   const unsigned kMaxK = parameters->k == 0 ? 2000 : parameters->k;
   const unsigned kSteps = parameters->steps == 0 ? 40 : parameters->steps;
   const unsigned kStepSize = MAX((kMaxK - kMinK) / kSteps, 1);
   const unsigned kIterations =
       (1 + (kMaxD - kMinD) / 2) * (1 + (kMaxK - kMinK) / kStepSize);
   const unsigned shrinkDict = 0;
   /* Local variables */
   const int displayLevel = parameters->zParams.notificationLevel;
   unsigned iteration = 1;
   unsigned d;
   unsigned k;
   COVER_best_t best;
   POOL_ctx *pool = NULL;
   int warned = 0;
 
   /* Checks */
   if (splitPoint <= 0 || splitPoint > 1) {
     LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect parameters\n");
     return ERROR(parameter_outOfBound);
   }
   if (kMinK < kMaxD || kMaxK < kMinK) {
     LOCALDISPLAYLEVEL(displayLevel, 1, "Incorrect parameters\n");
     return ERROR(parameter_outOfBound);
   }
   if (nbSamples == 0) {
     DISPLAYLEVEL(1, "Cover must have at least one input file\n");
     return ERROR(srcSize_wrong);
   }
   if (dictBufferCapacity < ZDICT_DICTSIZE_MIN) {
     DISPLAYLEVEL(1, "dictBufferCapacity must be at least %u\n",
                  ZDICT_DICTSIZE_MIN);
     return ERROR(dstSize_tooSmall);
   }
   if (nbThreads > 1) {
     pool = POOL_create(nbThreads, 1);
     if (!pool) {
       return ERROR(memory_allocation);
     }
   }
   /* Initialization */
   COVER_best_init(&best);
   /* Turn down global display level to clean up display at level 2 and below */
   g_displayLevel = displayLevel == 0 ? 0 : displayLevel - 1;
   /* Loop through d first because each new value needs a new context */
   LOCALDISPLAYLEVEL(displayLevel, 2, "Trying %u different sets of parameters\n",
                     kIterations);
   for (d = kMinD; d <= kMaxD; d += 2) {
     /* Initialize the context for this value of d */
     COVER_ctx_t ctx;
     LOCALDISPLAYLEVEL(displayLevel, 3, "d=%u\n", d);
     {
       const size_t initVal = COVER_ctx_init(&ctx, samplesBuffer, samplesSizes, nbSamples, d, splitPoint);
       if (ZSTD_isError(initVal)) {
         LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to initialize context\n");
         COVER_best_destroy(&best);
         POOL_free(pool);
         return initVal;
       }
     }
     if (!warned) {
       COVER_warnOnSmallCorpus(dictBufferCapacity, ctx.suffixSize, displayLevel);
       warned = 1;
     }
     /* Loop through k reusing the same context */
     for (k = kMinK; k <= kMaxK; k += kStepSize) {
       /* Prepare the arguments */
       COVER_tryParameters_data_t *data = (COVER_tryParameters_data_t *)malloc(
           sizeof(COVER_tryParameters_data_t));
       LOCALDISPLAYLEVEL(displayLevel, 3, "k=%u\n", k);
       if (!data) {
         LOCALDISPLAYLEVEL(displayLevel, 1, "Failed to allocate parameters\n");
         COVER_best_destroy(&best);
         COVER_ctx_destroy(&ctx);
         POOL_free(pool);
         return ERROR(memory_allocation);
       }
       data->ctx = &ctx;
       data->best = &best;
       data->dictBufferCapacity = dictBufferCapacity;
       data->parameters = *parameters;
       data->parameters.k = k;
       data->parameters.d = d;
       data->parameters.splitPoint = splitPoint;
       data->parameters.steps = kSteps;
       data->parameters.shrinkDict = shrinkDict;
       data->parameters.zParams.notificationLevel = g_displayLevel;
       /* Check the parameters */
       if (!COVER_checkParameters(data->parameters, dictBufferCapacity)) {
         DISPLAYLEVEL(1, "Cover parameters incorrect\n");
         free(data);
         continue;
       }
       /* Call the function and pass ownership of data to it */
       COVER_best_start(&best);
       if (pool) {
         POOL_add(pool, &COVER_tryParameters, data);
       } else {
         COVER_tryParameters(data);
       }
       /* Print status */
       LOCALDISPLAYUPDATE(displayLevel, 2, "\r%u%%       ",
                          (unsigned)((iteration * 100) / kIterations));
       ++iteration;
     }
     COVER_best_wait(&best);
     COVER_ctx_destroy(&ctx);
   }
   LOCALDISPLAYLEVEL(displayLevel, 2, "\r%79s\r", "");
   /* Fill the output buffer and parameters with output of the best parameters */
   {
     const size_t dictSize = best.dictSize;
     if (ZSTD_isError(best.compressedSize)) {
       const size_t compressedSize = best.compressedSize;
       COVER_best_destroy(&best);
       POOL_free(pool);
       return compressedSize;
     }
     *parameters = best.parameters;
     memcpy(dictBuffer, best.dict, dictSize);
     COVER_best_destroy(&best);
     POOL_free(pool);
     return dictSize;
   }
 }
Index: head/sys/contrib/zstd/lib/dictBuilder/zdict.c
===================================================================
--- head/sys/contrib/zstd/lib/dictBuilder/zdict.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/dictBuilder/zdict.c	(revision 354777)
@@ -1,1111 +1,1111 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /*-**************************************
 *  Tuning parameters
 ****************************************/
 #define MINRATIO 4   /* minimum nb of apparition to be selected in dictionary */
 #define ZDICT_MAX_SAMPLES_SIZE (2000U << 20)
 #define ZDICT_MIN_SAMPLES_SIZE (ZDICT_CONTENTSIZE_MIN * MINRATIO)
 
 
 /*-**************************************
 *  Compiler Options
 ****************************************/
 /* Unix Large Files support (>4GB) */
 #define _FILE_OFFSET_BITS 64
 #if (defined(__sun__) && (!defined(__LP64__)))   /* Sun Solaris 32-bits requires specific definitions */
 #  define _LARGEFILE_SOURCE
 #elif ! defined(__LP64__)                        /* No point defining Large file for 64 bit */
 #  define _LARGEFILE64_SOURCE
 #endif
 
 
 /*-*************************************
 *  Dependencies
 ***************************************/
 #include         /* malloc, free */
 #include         /* memset */
 #include          /* fprintf, fopen, ftello64 */
 #include           /* clock */
 
 #include "mem.h"           /* read */
 #include "fse.h"           /* FSE_normalizeCount, FSE_writeNCount */
 #define HUF_STATIC_LINKING_ONLY
 #include "huf.h"           /* HUF_buildCTable, HUF_writeCTable */
 #include "zstd_internal.h" /* includes zstd.h */
 #include "xxhash.h"        /* XXH64 */
 #include "divsufsort.h"
 #ifndef ZDICT_STATIC_LINKING_ONLY
 #  define ZDICT_STATIC_LINKING_ONLY
 #endif
 #include "zdict.h"
 
 
 /*-*************************************
 *  Constants
 ***************************************/
 #define KB *(1 <<10)
 #define MB *(1 <<20)
 #define GB *(1U<<30)
 
 #define DICTLISTSIZE_DEFAULT 10000
 
 #define NOISELENGTH 32
 
 static const int g_compressionLevel_default = 3;
 static const U32 g_selectivity_default = 9;
 
 
 /*-*************************************
 *  Console display
 ***************************************/
 #define DISPLAY(...)         { fprintf(stderr, __VA_ARGS__); fflush( stderr ); }
 #define DISPLAYLEVEL(l, ...) if (notificationLevel>=l) { DISPLAY(__VA_ARGS__); }    /* 0 : no display;   1: errors;   2: default;  3: details;  4: debug */
 
 static clock_t ZDICT_clockSpan(clock_t nPrevious) { return clock() - nPrevious; }
 
 static void ZDICT_printHex(const void* ptr, size_t length)
 {
     const BYTE* const b = (const BYTE*)ptr;
     size_t u;
     for (u=0; u126) c = '.';   /* non-printable char */
         DISPLAY("%c", c);
     }
 }
 
 
 /*-********************************************************
 *  Helper functions
 **********************************************************/
 unsigned ZDICT_isError(size_t errorCode) { return ERR_isError(errorCode); }
 
 const char* ZDICT_getErrorName(size_t errorCode) { return ERR_getErrorName(errorCode); }
 
 unsigned ZDICT_getDictID(const void* dictBuffer, size_t dictSize)
 {
     if (dictSize < 8) return 0;
     if (MEM_readLE32(dictBuffer) != ZSTD_MAGIC_DICTIONARY) return 0;
     return MEM_readLE32((const char*)dictBuffer + 4);
 }
 
 
 /*-********************************************************
 *  Dictionary training functions
 **********************************************************/
 static unsigned ZDICT_NbCommonBytes (size_t val)
 {
     if (MEM_isLittleEndian()) {
         if (MEM_64bits()) {
 #       if defined(_MSC_VER) && defined(_WIN64)
             unsigned long r = 0;
             _BitScanForward64( &r, (U64)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_ctzll((U64)val) >> 3);
 #       else
             static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
             return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
 #       endif
         } else { /* 32 bits */
 #       if defined(_MSC_VER)
             unsigned long r=0;
             _BitScanForward( &r, (U32)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_ctz((U32)val) >> 3);
 #       else
             static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
             return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
 #       endif
         }
     } else {  /* Big Endian CPU */
         if (MEM_64bits()) {
 #       if defined(_MSC_VER) && defined(_WIN64)
             unsigned long r = 0;
             _BitScanReverse64( &r, val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_clzll(val) >> 3);
 #       else
             unsigned r;
             const unsigned n32 = sizeof(size_t)*4;   /* calculate this way due to compiler complaining in 32-bits mode */
             if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; }
             if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
             r += (!val);
             return r;
 #       endif
         } else { /* 32 bits */
 #       if defined(_MSC_VER)
             unsigned long r = 0;
             _BitScanReverse( &r, (unsigned long)val );
             return (unsigned)(r>>3);
 #       elif defined(__GNUC__) && (__GNUC__ >= 3)
             return (__builtin_clz((U32)val) >> 3);
 #       else
             unsigned r;
             if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
             r += (!val);
             return r;
 #       endif
     }   }
 }
 
 
 /*! ZDICT_count() :
     Count the nb of common bytes between 2 pointers.
     Note : this function presumes end of buffer followed by noisy guard band.
 */
 static size_t ZDICT_count(const void* pIn, const void* pMatch)
 {
     const char* const pStart = (const char*)pIn;
     for (;;) {
         size_t const diff = MEM_readST(pMatch) ^ MEM_readST(pIn);
         if (!diff) {
             pIn = (const char*)pIn+sizeof(size_t);
             pMatch = (const char*)pMatch+sizeof(size_t);
             continue;
         }
         pIn = (const char*)pIn+ZDICT_NbCommonBytes(diff);
         return (size_t)((const char*)pIn - pStart);
     }
 }
 
 
 typedef struct {
     U32 pos;
     U32 length;
     U32 savings;
 } dictItem;
 
 static void ZDICT_initDictItem(dictItem* d)
 {
     d->pos = 1;
     d->length = 0;
     d->savings = (U32)(-1);
 }
 
 
 #define LLIMIT 64          /* heuristic determined experimentally */
 #define MINMATCHLENGTH 7   /* heuristic determined experimentally */
 static dictItem ZDICT_analyzePos(
                        BYTE* doneMarks,
                        const int* suffix, U32 start,
                        const void* buffer, U32 minRatio, U32 notificationLevel)
 {
     U32 lengthList[LLIMIT] = {0};
     U32 cumulLength[LLIMIT] = {0};
     U32 savings[LLIMIT] = {0};
     const BYTE* b = (const BYTE*)buffer;
     size_t maxLength = LLIMIT;
     size_t pos = suffix[start];
     U32 end = start;
     dictItem solution;
 
     /* init */
     memset(&solution, 0, sizeof(solution));
     doneMarks[pos] = 1;
 
     /* trivial repetition cases */
     if ( (MEM_read16(b+pos+0) == MEM_read16(b+pos+2))
        ||(MEM_read16(b+pos+1) == MEM_read16(b+pos+3))
        ||(MEM_read16(b+pos+2) == MEM_read16(b+pos+4)) ) {
         /* skip and mark segment */
         U16 const pattern16 = MEM_read16(b+pos+4);
         U32 u, patternEnd = 6;
         while (MEM_read16(b+pos+patternEnd) == pattern16) patternEnd+=2 ;
         if (b[pos+patternEnd] == b[pos+patternEnd-1]) patternEnd++;
         for (u=1; u= MINMATCHLENGTH);
     }
 
     /* look backward */
     {   size_t length;
         do {
             length = ZDICT_count(b + pos, b + *(suffix+start-1));
             if (length >=MINMATCHLENGTH) start--;
         } while(length >= MINMATCHLENGTH);
     }
 
     /* exit if not found a minimum nb of repetitions */
     if (end-start < minRatio) {
         U32 idx;
         for(idx=start; idx= %i at pos %7u  ", (unsigned)(end-start), MINMATCHLENGTH, (unsigned)pos);
         DISPLAYLEVEL(4, "\n");
 
         for (mml = MINMATCHLENGTH ; ; mml++) {
             BYTE currentChar = 0;
             U32 currentCount = 0;
             U32 currentID = refinedStart;
             U32 id;
             U32 selectedCount = 0;
             U32 selectedID = currentID;
             for (id =refinedStart; id < refinedEnd; id++) {
                 if (b[suffix[id] + mml] != currentChar) {
                     if (currentCount > selectedCount) {
                         selectedCount = currentCount;
                         selectedID = currentID;
                     }
                     currentID = id;
                     currentChar = b[ suffix[id] + mml];
                     currentCount = 0;
                 }
                 currentCount ++;
             }
             if (currentCount > selectedCount) {  /* for last */
                 selectedCount = currentCount;
                 selectedID = currentID;
             }
 
             if (selectedCount < minRatio)
                 break;
             refinedStart = selectedID;
             refinedEnd = refinedStart + selectedCount;
         }
 
         /* evaluate gain based on new dict */
         start = refinedStart;
         pos = suffix[refinedStart];
         end = start;
         memset(lengthList, 0, sizeof(lengthList));
 
         /* look forward */
         {   size_t length;
             do {
                 end++;
                 length = ZDICT_count(b + pos, b + suffix[end]);
                 if (length >= LLIMIT) length = LLIMIT-1;
                 lengthList[length]++;
             } while (length >=MINMATCHLENGTH);
         }
 
         /* look backward */
         {   size_t length = MINMATCHLENGTH;
             while ((length >= MINMATCHLENGTH) & (start > 0)) {
                 length = ZDICT_count(b + pos, b + suffix[start - 1]);
                 if (length >= LLIMIT) length = LLIMIT - 1;
                 lengthList[length]++;
                 if (length >= MINMATCHLENGTH) start--;
             }
         }
 
         /* largest useful length */
         memset(cumulLength, 0, sizeof(cumulLength));
         cumulLength[maxLength-1] = lengthList[maxLength-1];
         for (i=(int)(maxLength-2); i>=0; i--)
             cumulLength[i] = cumulLength[i+1] + lengthList[i];
 
         for (i=LLIMIT-1; i>=MINMATCHLENGTH; i--) if (cumulLength[i]>=minRatio) break;
         maxLength = i;
 
         /* reduce maxLength in case of final into repetitive data */
         {   U32 l = (U32)maxLength;
             BYTE const c = b[pos + maxLength-1];
             while (b[pos+l-2]==c) l--;
             maxLength = l;
         }
         if (maxLength < MINMATCHLENGTH) return solution;   /* skip : no long-enough solution */
 
         /* calculate savings */
         savings[5] = 0;
         for (i=MINMATCHLENGTH; i<=(int)maxLength; i++)
             savings[i] = savings[i-1] + (lengthList[i] * (i-3));
 
         DISPLAYLEVEL(4, "Selected dict at position %u, of length %u : saves %u (ratio: %.2f)  \n",
                      (unsigned)pos, (unsigned)maxLength, (unsigned)savings[maxLength], (double)savings[maxLength] / maxLength);
 
         solution.pos = (U32)pos;
         solution.length = (U32)maxLength;
         solution.savings = savings[maxLength];
 
         /* mark positions done */
         {   U32 id;
             for (id=start; id solution.length) length = solution.length;
                 }
                 pEnd = (U32)(testedPos + length);
                 for (p=testedPos; ppos;
     const U32 eltEnd = elt.pos + elt.length;
     const char* const buf = (const char*) buffer;
 
     /* tail overlap */
     U32 u; for (u=1; u elt.pos) && (table[u].pos <= eltEnd)) {  /* overlap, existing > new */
             /* append */
             U32 const addedLength = table[u].pos - elt.pos;
             table[u].length += addedLength;
             table[u].pos = elt.pos;
             table[u].savings += elt.savings * addedLength / elt.length;   /* rough approx */
             table[u].savings += elt.length / 8;    /* rough approx bonus */
             elt = table[u];
             /* sort : improve rank */
             while ((u>1) && (table[u-1].savings < elt.savings))
             table[u] = table[u-1], u--;
             table[u] = elt;
             return u;
     }   }
 
     /* front overlap */
     for (u=1; u= elt.pos) && (table[u].pos < elt.pos)) {  /* overlap, existing < new */
             /* append */
             int const addedLength = (int)eltEnd - (table[u].pos + table[u].length);
             table[u].savings += elt.length / 8;    /* rough approx bonus */
             if (addedLength > 0) {   /* otherwise, elt fully included into existing */
                 table[u].length += addedLength;
                 table[u].savings += elt.savings * addedLength / elt.length;   /* rough approx */
             }
             /* sort : improve rank */
             elt = table[u];
             while ((u>1) && (table[u-1].savings < elt.savings))
                 table[u] = table[u-1], u--;
             table[u] = elt;
             return u;
         }
 
         if (MEM_read64(buf + table[u].pos) == MEM_read64(buf + elt.pos + 1)) {
             if (isIncluded(buf + table[u].pos, buf + elt.pos + 1, table[u].length)) {
                 size_t const addedLength = MAX( (int)elt.length - (int)table[u].length , 1 );
                 table[u].pos = elt.pos;
                 table[u].savings += (U32)(elt.savings * addedLength / elt.length);
                 table[u].length = MIN(elt.length, table[u].length + 1);
                 return u;
             }
         }
     }
 
     return 0;
 }
 
 
 static void ZDICT_removeDictItem(dictItem* table, U32 id)
 {
     /* convention : table[0].pos stores nb of elts */
     U32 const max = table[0].pos;
     U32 u;
     if (!id) return;   /* protection, should never happen */
     for (u=id; upos--;
 }
 
 
 static void ZDICT_insertDictItem(dictItem* table, U32 maxSize, dictItem elt, const void* buffer)
 {
     /* merge if possible */
     U32 mergeId = ZDICT_tryMerge(table, elt, 0, buffer);
     if (mergeId) {
         U32 newMerge = 1;
         while (newMerge) {
             newMerge = ZDICT_tryMerge(table, table[mergeId], mergeId, buffer);
             if (newMerge) ZDICT_removeDictItem(table, mergeId);
             mergeId = newMerge;
         }
         return;
     }
 
     /* insert */
     {   U32 current;
         U32 nextElt = table->pos;
         if (nextElt >= maxSize) nextElt = maxSize-1;
         current = nextElt-1;
         while (table[current].savings < elt.savings) {
             table[current+1] = table[current];
             current--;
         }
         table[current+1] = elt;
         table->pos = nextElt+1;
     }
 }
 
 
 static U32 ZDICT_dictSize(const dictItem* dictList)
 {
     U32 u, dictSize = 0;
     for (u=1; u=l) { \
             if (ZDICT_clockSpan(displayClock) > refreshRate)  \
             { displayClock = clock(); DISPLAY(__VA_ARGS__); \
             if (notificationLevel>=4) fflush(stderr); } }
 
     /* init */
     DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */
     if (!suffix0 || !reverseSuffix || !doneMarks || !filePos) {
         result = ERROR(memory_allocation);
         goto _cleanup;
     }
     if (minRatio < MINRATIO) minRatio = MINRATIO;
     memset(doneMarks, 0, bufferSize+16);
 
     /* limit sample set size (divsufsort limitation)*/
     if (bufferSize > ZDICT_MAX_SAMPLES_SIZE) DISPLAYLEVEL(3, "sample set too large : reduced to %u MB ...\n", (unsigned)(ZDICT_MAX_SAMPLES_SIZE>>20));
     while (bufferSize > ZDICT_MAX_SAMPLES_SIZE) bufferSize -= fileSizes[--nbFiles];
 
     /* sort */
     DISPLAYLEVEL(2, "sorting %u files of total size %u MB ...\n", nbFiles, (unsigned)(bufferSize>>20));
     {   int const divSuftSortResult = divsufsort((const unsigned char*)buffer, suffix, (int)bufferSize, 0);
         if (divSuftSortResult != 0) { result = ERROR(GENERIC); goto _cleanup; }
     }
     suffix[bufferSize] = (int)bufferSize;   /* leads into noise */
     suffix0[0] = (int)bufferSize;           /* leads into noise */
     /* build reverse suffix sort */
     {   size_t pos;
         for (pos=0; pos < bufferSize; pos++)
             reverseSuffix[suffix[pos]] = (U32)pos;
         /* note filePos tracks borders between samples.
            It's not used at this stage, but planned to become useful in a later update */
         filePos[0] = 0;
         for (pos=1; pos> 21);
     }
 }
 
 
 typedef struct
 {
     ZSTD_CDict* dict;    /* dictionary */
     ZSTD_CCtx* zc;     /* working context */
     void* workPlace;   /* must be ZSTD_BLOCKSIZE_MAX allocated */
 } EStats_ress_t;
 
 #define MAXREPOFFSET 1024
 
 static void ZDICT_countEStats(EStats_ress_t esr, ZSTD_parameters params,
                               unsigned* countLit, unsigned* offsetcodeCount, unsigned* matchlengthCount, unsigned* litlengthCount, U32* repOffsets,
                               const void* src, size_t srcSize,
                               U32 notificationLevel)
 {
     size_t const blockSizeMax = MIN (ZSTD_BLOCKSIZE_MAX, 1 << params.cParams.windowLog);
     size_t cSize;
 
     if (srcSize > blockSizeMax) srcSize = blockSizeMax;   /* protection vs large samples */
     {   size_t const errorCode = ZSTD_compressBegin_usingCDict(esr.zc, esr.dict);
         if (ZSTD_isError(errorCode)) { DISPLAYLEVEL(1, "warning : ZSTD_compressBegin_usingCDict failed \n"); return; }
 
     }
     cSize = ZSTD_compressBlock(esr.zc, esr.workPlace, ZSTD_BLOCKSIZE_MAX, src, srcSize);
     if (ZSTD_isError(cSize)) { DISPLAYLEVEL(3, "warning : could not compress sample size %u \n", (unsigned)srcSize); return; }
 
     if (cSize) {  /* if == 0; block is not compressible */
         const seqStore_t* const seqStorePtr = ZSTD_getSeqStore(esr.zc);
 
         /* literals stats */
         {   const BYTE* bytePtr;
             for(bytePtr = seqStorePtr->litStart; bytePtr < seqStorePtr->lit; bytePtr++)
                 countLit[*bytePtr]++;
         }
 
         /* seqStats */
         {   U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
             ZSTD_seqToCodes(seqStorePtr);
 
             {   const BYTE* codePtr = seqStorePtr->ofCode;
                 U32 u;
                 for (u=0; umlCode;
                 U32 u;
                 for (u=0; ullCode;
                 U32 u;
                 for (u=0; u= 2) { /* rep offsets */
                 const seqDef* const seq = seqStorePtr->sequencesStart;
                 U32 offset1 = seq[0].offset - 3;
                 U32 offset2 = seq[1].offset - 3;
                 if (offset1 >= MAXREPOFFSET) offset1 = 0;
                 if (offset2 >= MAXREPOFFSET) offset2 = 0;
                 repOffsets[offset1] += 3;
                 repOffsets[offset2] += 1;
     }   }   }
 }
 
 static size_t ZDICT_totalSampleSize(const size_t* fileSizes, unsigned nbFiles)
 {
     size_t total=0;
     unsigned u;
     for (u=0; u0; u--) {
         offsetCount_t tmp;
         if (table[u-1].count >= table[u].count) break;
         tmp = table[u-1];
         table[u-1] = table[u];
         table[u] = tmp;
     }
 }
 
 /* ZDICT_flatLit() :
  * rewrite `countLit` to contain a mostly flat but still compressible distribution of literals.
  * necessary to avoid generating a non-compressible distribution that HUF_writeCTable() cannot encode.
  */
 static void ZDICT_flatLit(unsigned* countLit)
 {
     int u;
     for (u=1; u<256; u++) countLit[u] = 2;
     countLit[0]   = 4;
     countLit[253] = 1;
     countLit[254] = 1;
 }
 
 #define OFFCODE_MAX 30  /* only applicable to first block */
 static size_t ZDICT_analyzeEntropy(void*  dstBuffer, size_t maxDstSize,
                                    unsigned compressionLevel,
                              const void*  srcBuffer, const size_t* fileSizes, unsigned nbFiles,
                              const void* dictBuffer, size_t  dictBufferSize,
                                    unsigned notificationLevel)
 {
     unsigned countLit[256];
     HUF_CREATE_STATIC_CTABLE(hufTable, 255);
     unsigned offcodeCount[OFFCODE_MAX+1];
     short offcodeNCount[OFFCODE_MAX+1];
     U32 offcodeMax = ZSTD_highbit32((U32)(dictBufferSize + 128 KB));
     unsigned matchLengthCount[MaxML+1];
     short matchLengthNCount[MaxML+1];
     unsigned litLengthCount[MaxLL+1];
     short litLengthNCount[MaxLL+1];
     U32 repOffset[MAXREPOFFSET];
     offsetCount_t bestRepOffset[ZSTD_REP_NUM+1];
     EStats_ress_t esr = { NULL, NULL, NULL };
     ZSTD_parameters params;
     U32 u, huffLog = 11, Offlog = OffFSELog, mlLog = MLFSELog, llLog = LLFSELog, total;
     size_t pos = 0, errorCode;
     size_t eSize = 0;
     size_t const totalSrcSize = ZDICT_totalSampleSize(fileSizes, nbFiles);
     size_t const averageSampleSize = totalSrcSize / (nbFiles + !nbFiles);
     BYTE* dstPtr = (BYTE*)dstBuffer;
 
     /* init */
     DEBUGLOG(4, "ZDICT_analyzeEntropy");
     if (offcodeMax>OFFCODE_MAX) { eSize = ERROR(dictionaryCreation_failed); goto _cleanup; }   /* too large dictionary */
     for (u=0; u<256; u++) countLit[u] = 1;   /* any character must be described */
     for (u=0; u<=offcodeMax; u++) offcodeCount[u] = 1;
     for (u=0; u<=MaxML; u++) matchLengthCount[u] = 1;
     for (u=0; u<=MaxLL; u++) litLengthCount[u] = 1;
     memset(repOffset, 0, sizeof(repOffset));
     repOffset[1] = repOffset[4] = repOffset[8] = 1;
     memset(bestRepOffset, 0, sizeof(bestRepOffset));
     if (compressionLevel==0) compressionLevel = g_compressionLevel_default;
     params = ZSTD_getParams(compressionLevel, averageSampleSize, dictBufferSize);
 
     esr.dict = ZSTD_createCDict_advanced(dictBuffer, dictBufferSize, ZSTD_dlm_byRef, ZSTD_dct_rawContent, params.cParams, ZSTD_defaultCMem);
     esr.zc = ZSTD_createCCtx();
     esr.workPlace = malloc(ZSTD_BLOCKSIZE_MAX);
     if (!esr.dict || !esr.zc || !esr.workPlace) {
         eSize = ERROR(memory_allocation);
         DISPLAYLEVEL(1, "Not enough memory \n");
         goto _cleanup;
     }
 
     /* collect stats on all samples */
     for (u=0; u dictBufferCapacity) dictContentSize = dictBufferCapacity - hSize;
     {   size_t const dictSize = hSize + dictContentSize;
         char* dictEnd = (char*)dictBuffer + dictSize;
         memmove(dictEnd - dictContentSize, customDictContent, dictContentSize);
         memcpy(dictBuffer, header, hSize);
         return dictSize;
     }
 }
 
 
 static size_t ZDICT_addEntropyTablesFromBuffer_advanced(
         void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
         const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
         ZDICT_params_t params)
 {
     int const compressionLevel = (params.compressionLevel == 0) ? g_compressionLevel_default : params.compressionLevel;
     U32 const notificationLevel = params.notificationLevel;
     size_t hSize = 8;
 
     /* calculate entropy tables */
     DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */
     DISPLAYLEVEL(2, "statistics ... \n");
     {   size_t const eSize = ZDICT_analyzeEntropy((char*)dictBuffer+hSize, dictBufferCapacity-hSize,
                                   compressionLevel,
                                   samplesBuffer, samplesSizes, nbSamples,
                                   (char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize,
                                   notificationLevel);
         if (ZDICT_isError(eSize)) return eSize;
         hSize += eSize;
     }
 
     /* add dictionary header (after entropy tables) */
     MEM_writeLE32(dictBuffer, ZSTD_MAGIC_DICTIONARY);
     {   U64 const randomID = XXH64((char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize, 0);
         U32 const compliantID = (randomID % ((1U<<31)-32768)) + 32768;
         U32 const dictID = params.dictID ? params.dictID : compliantID;
         MEM_writeLE32((char*)dictBuffer+4, dictID);
     }
 
     if (hSize + dictContentSize < dictBufferCapacity)
         memmove((char*)dictBuffer + hSize, (char*)dictBuffer + dictBufferCapacity - dictContentSize, dictContentSize);
     return MIN(dictBufferCapacity, hSize+dictContentSize);
 }
 
 /* Hidden declaration for dbio.c */
 size_t ZDICT_trainFromBuffer_unsafe_legacy(
                             void* dictBuffer, size_t maxDictSize,
                             const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                             ZDICT_legacy_params_t params);
 /*! ZDICT_trainFromBuffer_unsafe_legacy() :
 *   Warning : `samplesBuffer` must be followed by noisy guard band.
 *   @return : size of dictionary, or an error code which can be tested with ZDICT_isError()
 */
 size_t ZDICT_trainFromBuffer_unsafe_legacy(
                             void* dictBuffer, size_t maxDictSize,
                             const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                             ZDICT_legacy_params_t params)
 {
     U32 const dictListSize = MAX(MAX(DICTLISTSIZE_DEFAULT, nbSamples), (U32)(maxDictSize/16));
     dictItem* const dictList = (dictItem*)malloc(dictListSize * sizeof(*dictList));
     unsigned const selectivity = params.selectivityLevel == 0 ? g_selectivity_default : params.selectivityLevel;
     unsigned const minRep = (selectivity > 30) ? MINRATIO : nbSamples >> selectivity;
     size_t const targetDictSize = maxDictSize;
     size_t const samplesBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples);
     size_t dictSize = 0;
     U32 const notificationLevel = params.zParams.notificationLevel;
 
     /* checks */
     if (!dictList) return ERROR(memory_allocation);
     if (maxDictSize < ZDICT_DICTSIZE_MIN) { free(dictList); return ERROR(dstSize_tooSmall); }   /* requested dictionary size is too small */
     if (samplesBuffSize < ZDICT_MIN_SAMPLES_SIZE) { free(dictList); return ERROR(dictionaryCreation_failed); }   /* not enough source to create dictionary */
 
     /* init */
     ZDICT_initDictItem(dictList);
 
     /* build dictionary */
     ZDICT_trainBuffer_legacy(dictList, dictListSize,
                        samplesBuffer, samplesBuffSize,
                        samplesSizes, nbSamples,
                        minRep, notificationLevel);
 
     /* display best matches */
     if (params.zParams.notificationLevel>= 3) {
         unsigned const nb = MIN(25, dictList[0].pos);
         unsigned const dictContentSize = ZDICT_dictSize(dictList);
         unsigned u;
         DISPLAYLEVEL(3, "\n %u segments found, of total size %u \n", (unsigned)dictList[0].pos-1, dictContentSize);
         DISPLAYLEVEL(3, "list %u best segments \n", nb-1);
         for (u=1; u samplesBuffSize) || ((pos + length) > samplesBuffSize)) {
                 free(dictList);
                 return ERROR(GENERIC);   /* should never happen */
             }
             DISPLAYLEVEL(3, "%3u:%3u bytes at pos %8u, savings %7u bytes |",
                          u, length, pos, (unsigned)dictList[u].savings);
             ZDICT_printHex((const char*)samplesBuffer+pos, printedLength);
             DISPLAYLEVEL(3, "| \n");
     }   }
 
 
     /* create dictionary */
     {   unsigned dictContentSize = ZDICT_dictSize(dictList);
         if (dictContentSize < ZDICT_CONTENTSIZE_MIN) { free(dictList); return ERROR(dictionaryCreation_failed); }   /* dictionary content too small */
         if (dictContentSize < targetDictSize/4) {
             DISPLAYLEVEL(2, "!  warning : selected content significantly smaller than requested (%u < %u) \n", dictContentSize, (unsigned)maxDictSize);
             if (samplesBuffSize < 10 * targetDictSize)
                 DISPLAYLEVEL(2, "!  consider increasing the number of samples (total size : %u MB)\n", (unsigned)(samplesBuffSize>>20));
             if (minRep > MINRATIO) {
                 DISPLAYLEVEL(2, "!  consider increasing selectivity to produce larger dictionary (-s%u) \n", selectivity+1);
                 DISPLAYLEVEL(2, "!  note : larger dictionaries are not necessarily better, test its efficiency on samples \n");
             }
         }
 
         if ((dictContentSize > targetDictSize*3) && (nbSamples > 2*MINRATIO) && (selectivity>1)) {
             unsigned proposedSelectivity = selectivity-1;
             while ((nbSamples >> proposedSelectivity) <= MINRATIO) { proposedSelectivity--; }
             DISPLAYLEVEL(2, "!  note : calculated dictionary significantly larger than requested (%u > %u) \n", dictContentSize, (unsigned)maxDictSize);
             DISPLAYLEVEL(2, "!  consider increasing dictionary size, or produce denser dictionary (-s%u) \n", proposedSelectivity);
             DISPLAYLEVEL(2, "!  always test dictionary efficiency on real samples \n");
         }
 
         /* limit dictionary size */
         {   U32 const max = dictList->pos;   /* convention : nb of useful elts within dictList */
             U32 currentSize = 0;
             U32 n; for (n=1; n targetDictSize) { currentSize -= dictList[n].length; break; }
             }
             dictList->pos = n;
             dictContentSize = currentSize;
         }
 
         /* build dict content */
         {   U32 u;
             BYTE* ptr = (BYTE*)dictBuffer + maxDictSize;
             for (u=1; upos; u++) {
                 U32 l = dictList[u].length;
                 ptr -= l;
                 if (ptr<(BYTE*)dictBuffer) { free(dictList); return ERROR(GENERIC); }   /* should not happen */
                 memcpy(ptr, (const char*)samplesBuffer+dictList[u].pos, l);
         }   }
 
         dictSize = ZDICT_addEntropyTablesFromBuffer_advanced(dictBuffer, dictContentSize, maxDictSize,
                                                              samplesBuffer, samplesSizes, nbSamples,
                                                              params.zParams);
     }
 
     /* clean up */
     free(dictList);
     return dictSize;
 }
 
 
 /* ZDICT_trainFromBuffer_legacy() :
  * issue : samplesBuffer need to be followed by a noisy guard band.
  * work around : duplicate the buffer, and add the noise */
 size_t ZDICT_trainFromBuffer_legacy(void* dictBuffer, size_t dictBufferCapacity,
                               const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
                               ZDICT_legacy_params_t params)
 {
     size_t result;
     void* newBuff;
     size_t const sBuffSize = ZDICT_totalSampleSize(samplesSizes, nbSamples);
     if (sBuffSize < ZDICT_MIN_SAMPLES_SIZE) return 0;   /* not enough content => no dictionary */
 
     newBuff = malloc(sBuffSize + NOISELENGTH);
     if (!newBuff) return ERROR(memory_allocation);
 
     memcpy(newBuff, samplesBuffer, sBuffSize);
     ZDICT_fillNoise((char*)newBuff + sBuffSize, NOISELENGTH);   /* guard band, for end of buffer condition */
 
     result =
         ZDICT_trainFromBuffer_unsafe_legacy(dictBuffer, dictBufferCapacity, newBuff,
                                             samplesSizes, nbSamples, params);
     free(newBuff);
     return result;
 }
 
 
 size_t ZDICT_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
                              const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples)
 {
     ZDICT_fastCover_params_t params;
     DEBUGLOG(3, "ZDICT_trainFromBuffer");
     memset(¶ms, 0, sizeof(params));
     params.d = 8;
     params.steps = 4;
     /* Default to level 6 since no compression level information is available */
     params.zParams.compressionLevel = 3;
 #if defined(DEBUGLEVEL) && (DEBUGLEVEL>=1)
     params.zParams.notificationLevel = DEBUGLEVEL;
 #endif
     return ZDICT_optimizeTrainFromBuffer_fastCover(dictBuffer, dictBufferCapacity,
                                                samplesBuffer, samplesSizes, nbSamples,
                                                ¶ms);
 }
 
 size_t ZDICT_addEntropyTablesFromBuffer(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
                                   const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples)
 {
     ZDICT_params_t params;
     memset(¶ms, 0, sizeof(params));
     return ZDICT_addEntropyTablesFromBuffer_advanced(dictBuffer, dictContentSize, dictBufferCapacity,
                                                      samplesBuffer, samplesSizes, nbSamples,
                                                      params);
 }
Index: head/sys/contrib/zstd/lib/legacy/zstd_v01.c
===================================================================
--- head/sys/contrib/zstd/lib/legacy/zstd_v01.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/legacy/zstd_v01.c	(revision 354777)
@@ -1,2152 +1,2152 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 /******************************************
 *  Includes
 ******************************************/
 #include     /* size_t, ptrdiff_t */
 #include "zstd_v01.h"
 #include "error_private.h"
 
 
 /******************************************
 *  Static allocation
 ******************************************/
 /* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 *  Increasing memory usage improves compression ratio
 *  Reduced memory usage can improve speed, due to cache effect
 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
 #define FSE_MAX_MEMORY_USAGE 14
 #define FSE_DEFAULT_MEMORY_USAGE 13
 
 /* FSE_MAX_SYMBOL_VALUE :
 *  Maximum symbol value authorized.
 *  Required for proper stack allocation */
 #define FSE_MAX_SYMBOL_VALUE 255
 
 
 /****************************************************************
 *  template functions type & suffix
 ****************************************************************/
 #define FSE_FUNCTION_TYPE BYTE
 #define FSE_FUNCTION_EXTENSION
 
 
 /****************************************************************
 *  Byte symbol type
 ****************************************************************/
 typedef struct
 {
     unsigned short newState;
     unsigned char  symbol;
     unsigned char  nbBits;
 } FSE_decode_t;   /* size == U32 */
 
 
 
 /****************************************************************
 *  Compiler specifics
 ****************************************************************/
 #ifdef _MSC_VER    /* Visual Studio */
 #  define FORCE_INLINE static __forceinline
 #  include                     /* For Visual 2005 */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
 #else
 #  define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 #    ifdef __GNUC__
 #      define FORCE_INLINE static inline __attribute__((always_inline))
 #    else
 #      define FORCE_INLINE static inline
 #    endif
 #  else
 #    define FORCE_INLINE static
 #  endif /* __STDC_VERSION__ */
 #endif
 
 
 /****************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
 #include       /* printf (debug) */
 
 
 #ifndef MEM_ACCESS_MODULE
 #define MEM_ACCESS_MODULE
 /****************************************************************
 *  Basic Types
 *****************************************************************/
 #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 # include 
 typedef  uint8_t BYTE;
 typedef uint16_t U16;
 typedef  int16_t S16;
 typedef uint32_t U32;
 typedef  int32_t S32;
 typedef uint64_t U64;
 typedef  int64_t S64;
 #else
 typedef unsigned char       BYTE;
 typedef unsigned short      U16;
 typedef   signed short      S16;
 typedef unsigned int        U32;
 typedef   signed int        S32;
 typedef unsigned long long  U64;
 typedef   signed long long  S64;
 #endif
 
 #endif   /* MEM_ACCESS_MODULE */
 
 /****************************************************************
 *  Memory I/O
 *****************************************************************/
 /* FSE_FORCE_MEMORY_ACCESS
  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
  * The below switch allow to select different access method for improved performance.
  * Method 0 (default) : use `memcpy()`. Safe and portable.
  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method is portable but violate C standard.
  *            It can generate buggy code on targets generating assembly depending on alignment.
  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
 #ifndef FSE_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define FSE_FORCE_MEMORY_ACCESS 2
 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
 #    define FSE_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
 
 
 static unsigned FSE_32bits(void)
 {
     return sizeof(void*)==4;
 }
 
 static unsigned FSE_isLittleEndian(void)
 {
     const union { U32 i; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
     return one.c[0];
 }
 
 #if defined(FSE_FORCE_MEMORY_ACCESS) && (FSE_FORCE_MEMORY_ACCESS==2)
 
 static U16 FSE_read16(const void* memPtr) { return *(const U16*) memPtr; }
 static U32 FSE_read32(const void* memPtr) { return *(const U32*) memPtr; }
 static U64 FSE_read64(const void* memPtr) { return *(const U64*) memPtr; }
 
 #elif defined(FSE_FORCE_MEMORY_ACCESS) && (FSE_FORCE_MEMORY_ACCESS==1)
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
 typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
 
 static U16 FSE_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
 static U32 FSE_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
 static U64 FSE_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
 
 #else
 
 static U16 FSE_read16(const void* memPtr)
 {
     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 static U32 FSE_read32(const void* memPtr)
 {
     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 static U64 FSE_read64(const void* memPtr)
 {
     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 #endif // FSE_FORCE_MEMORY_ACCESS
 
 static U16 FSE_readLE16(const void* memPtr)
 {
     if (FSE_isLittleEndian())
         return FSE_read16(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U16)(p[0] + (p[1]<<8));
     }
 }
 
 static U32 FSE_readLE32(const void* memPtr)
 {
     if (FSE_isLittleEndian())
         return FSE_read32(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
     }
 }
 
 
 static U64 FSE_readLE64(const void* memPtr)
 {
     if (FSE_isLittleEndian())
         return FSE_read64(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
     }
 }
 
 static size_t FSE_readLEST(const void* memPtr)
 {
     if (FSE_32bits())
         return (size_t)FSE_readLE32(memPtr);
     else
         return (size_t)FSE_readLE64(memPtr);
 }
 
 
 
 /****************************************************************
 *  Constants
 *****************************************************************/
 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
 #define FSE_MAX_TABLESIZE (1U< FSE_TABLELOG_ABSOLUTE_MAX
 #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
 #endif
 
 
 /****************************************************************
 *  Error Management
 ****************************************************************/
 #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
 /****************************************************************
 *  Complex types
 ****************************************************************/
 typedef struct
 {
     int deltaFindState;
     U32 deltaNbBits;
 } FSE_symbolCompressionTransform; /* total 8 bytes */
 
 typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
 
 /****************************************************************
 *  Internal functions
 ****************************************************************/
 FORCE_INLINE unsigned FSE_highbit32 (U32 val)
 {
 #   if defined(_MSC_VER)   /* Visual */
     unsigned long r;
     _BitScanReverse ( &r, val );
     return (unsigned) r;
 #   elif defined(__GNUC__) && (GCC_VERSION >= 304)   /* GCC Intrinsic */
-    return 31 - __builtin_clz (val);
+    return __builtin_clz (val) ^ 31;
 #   else   /* Software version */
     static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
     U32 v = val;
     unsigned r;
     v |= v >> 1;
     v |= v >> 2;
     v |= v >> 4;
     v |= v >> 8;
     v |= v >> 16;
     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
     return r;
 #   endif
 }
 
 
 /****************************************************************
 *  Templates
 ****************************************************************/
 /*
   designed to be included
   for type-specific functions (template emulation in C)
   Objective is to write these functions only once, for improved maintenance
 */
 
 /* safety checks */
 #ifndef FSE_FUNCTION_EXTENSION
 #  error "FSE_FUNCTION_EXTENSION must be defined"
 #endif
 #ifndef FSE_FUNCTION_TYPE
 #  error "FSE_FUNCTION_TYPE must be defined"
 #endif
 
 /* Function names */
 #define FSE_CAT(X,Y) X##Y
 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
 
 
 
 static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
 
 #define FSE_DECODE_TYPE FSE_decode_t
 
 
 typedef struct {
     U16 tableLog;
     U16 fastMode;
 } FSE_DTableHeader;   /* sizeof U32 */
 
 static size_t FSE_buildDTable
 (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)(ptr) + 1;   /* because dt is unsigned, 32-bits aligned on 32-bits */
     const U32 tableSize = 1 << tableLog;
     const U32 tableMask = tableSize-1;
     const U32 step = FSE_tableStep(tableSize);
     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
     U32 position = 0;
     U32 highThreshold = tableSize-1;
     const S16 largeLimit= (S16)(1 << (tableLog-1));
     U32 noLarge = 1;
     U32 s;
 
     /* Sanity Checks */
     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return (size_t)-FSE_ERROR_maxSymbolValue_tooLarge;
     if (tableLog > FSE_MAX_TABLELOG) return (size_t)-FSE_ERROR_tableLog_tooLarge;
 
     /* Init, lay down lowprob symbols */
     DTableH[0].tableLog = (U16)tableLog;
     for (s=0; s<=maxSymbolValue; s++)
     {
         if (normalizedCounter[s]==-1)
         {
             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
             symbolNext[s] = 1;
         }
         else
         {
             if (normalizedCounter[s] >= largeLimit) noLarge=0;
             symbolNext[s] = normalizedCounter[s];
         }
     }
 
     /* Spread symbols */
     for (s=0; s<=maxSymbolValue; s++)
     {
         int i;
         for (i=0; i highThreshold) position = (position + step) & tableMask;   /* lowprob area */
         }
     }
 
     if (position!=0) return (size_t)-FSE_ERROR_GENERIC;   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
 
     /* Build Decoding table */
     {
         U32 i;
         for (i=0; ifastMode = (U16)noLarge;
     return 0;
 }
 
 
 /******************************************
 *  FSE byte symbol
 ******************************************/
 #ifndef FSE_COMMONDEFS_ONLY
 
 static unsigned FSE_isError(size_t code) { return (code > (size_t)(-FSE_ERROR_maxCode)); }
 
 static short FSE_abs(short a)
 {
     return a<0? -a : a;
 }
 
 
 /****************************************************************
 *  Header bitstream management
 ****************************************************************/
 static size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
                  const void* headerBuffer, size_t hbSize)
 {
     const BYTE* const istart = (const BYTE*) headerBuffer;
     const BYTE* const iend = istart + hbSize;
     const BYTE* ip = istart;
     int nbBits;
     int remaining;
     int threshold;
     U32 bitStream;
     int bitCount;
     unsigned charnum = 0;
     int previous0 = 0;
 
     if (hbSize < 4) return (size_t)-FSE_ERROR_srcSize_wrong;
     bitStream = FSE_readLE32(ip);
     nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
     if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return (size_t)-FSE_ERROR_tableLog_tooLarge;
     bitStream >>= 4;
     bitCount = 4;
     *tableLogPtr = nbBits;
     remaining = (1<1) && (charnum<=*maxSVPtr))
     {
         if (previous0)
         {
             unsigned n0 = charnum;
             while ((bitStream & 0xFFFF) == 0xFFFF)
             {
                 n0+=24;
                 if (ip < iend-5)
                 {
                     ip+=2;
                     bitStream = FSE_readLE32(ip) >> bitCount;
                 }
                 else
                 {
                     bitStream >>= 16;
                     bitCount+=16;
                 }
             }
             while ((bitStream & 3) == 3)
             {
                 n0+=3;
                 bitStream>>=2;
                 bitCount+=2;
             }
             n0 += bitStream & 3;
             bitCount += 2;
             if (n0 > *maxSVPtr) return (size_t)-FSE_ERROR_maxSymbolValue_tooSmall;
             while (charnum < n0) normalizedCounter[charnum++] = 0;
             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
             {
                 ip += bitCount>>3;
                 bitCount &= 7;
                 bitStream = FSE_readLE32(ip) >> bitCount;
             }
             else
                 bitStream >>= 2;
         }
         {
             const short max = (short)((2*threshold-1)-remaining);
             short count;
 
             if ((bitStream & (threshold-1)) < (U32)max)
             {
                 count = (short)(bitStream & (threshold-1));
                 bitCount   += nbBits-1;
             }
             else
             {
                 count = (short)(bitStream & (2*threshold-1));
                 if (count >= threshold) count -= max;
                 bitCount   += nbBits;
             }
 
             count--;   /* extra accuracy */
             remaining -= FSE_abs(count);
             normalizedCounter[charnum++] = count;
             previous0 = !count;
             while (remaining < threshold)
             {
                 nbBits--;
                 threshold >>= 1;
             }
 
             {
                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
                 {
                     ip += bitCount>>3;
                     bitCount &= 7;
                 }
                 else
                 {
                     bitCount -= (int)(8 * (iend - 4 - ip));
                     ip = iend - 4;
                 }
                 bitStream = FSE_readLE32(ip) >> (bitCount & 31);
             }
         }
     }
     if (remaining != 1) return (size_t)-FSE_ERROR_GENERIC;
     *maxSVPtr = charnum-1;
 
     ip += (bitCount+7)>>3;
     if ((size_t)(ip-istart) > hbSize) return (size_t)-FSE_ERROR_srcSize_wrong;
     return ip-istart;
 }
 
 
 /*********************************************************
 *  Decompression (Byte symbols)
 *********************************************************/
 static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
 
     DTableH->tableLog = 0;
     DTableH->fastMode = 0;
 
     cell->newState = 0;
     cell->symbol = symbolValue;
     cell->nbBits = 0;
 
     return 0;
 }
 
 
 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
     const unsigned tableSize = 1 << nbBits;
     const unsigned tableMask = tableSize - 1;
     const unsigned maxSymbolValue = tableMask;
     unsigned s;
 
     /* Sanity checks */
     if (nbBits < 1) return (size_t)-FSE_ERROR_GENERIC;             /* min size */
 
     /* Build Decoding Table */
     DTableH->tableLog = (U16)nbBits;
     DTableH->fastMode = 1;
     for (s=0; s<=maxSymbolValue; s++)
     {
         dinfo[s].newState = 0;
         dinfo[s].symbol = (BYTE)s;
         dinfo[s].nbBits = (BYTE)nbBits;
     }
 
     return 0;
 }
 
 
 /* FSE_initDStream
  * Initialize a FSE_DStream_t.
  * srcBuffer must point at the beginning of an FSE block.
  * The function result is the size of the FSE_block (== srcSize).
  * If srcSize is too small, the function will return an errorCode;
  */
 static size_t FSE_initDStream(FSE_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
 {
     if (srcSize < 1) return (size_t)-FSE_ERROR_srcSize_wrong;
 
     if (srcSize >=  sizeof(size_t))
     {
         U32 contain32;
         bitD->start = (const char*)srcBuffer;
         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
         bitD->bitContainer = FSE_readLEST(bitD->ptr);
         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
         if (contain32 == 0) return (size_t)-FSE_ERROR_GENERIC;   /* stop bit not present */
         bitD->bitsConsumed = 8 - FSE_highbit32(contain32);
     }
     else
     {
         U32 contain32;
         bitD->start = (const char*)srcBuffer;
         bitD->ptr   = bitD->start;
         bitD->bitContainer = *(const BYTE*)(bitD->start);
         switch(srcSize)
         {
             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
                     /* fallthrough */
             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
                     /* fallthrough */
             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
                     /* fallthrough */
             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
                     /* fallthrough */
             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
                     /* fallthrough */
             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
                     /* fallthrough */
             default:;
         }
         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
         if (contain32 == 0) return (size_t)-FSE_ERROR_GENERIC;   /* stop bit not present */
         bitD->bitsConsumed = 8 - FSE_highbit32(contain32);
         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
     }
 
     return srcSize;
 }
 
 
 /*!FSE_lookBits
  * Provides next n bits from the bitContainer.
  * bitContainer is not modified (bits are still present for next read/look)
  * On 32-bits, maxNbBits==25
  * On 64-bits, maxNbBits==57
  * return : value extracted.
  */
 static size_t FSE_lookBits(FSE_DStream_t* bitD, U32 nbBits)
 {
     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
 }
 
 static size_t FSE_lookBitsFast(FSE_DStream_t* bitD, U32 nbBits)   /* only if nbBits >= 1 !! */
 {
     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
 }
 
 static void FSE_skipBits(FSE_DStream_t* bitD, U32 nbBits)
 {
     bitD->bitsConsumed += nbBits;
 }
 
 
 /*!FSE_readBits
  * Read next n bits from the bitContainer.
  * On 32-bits, don't read more than maxNbBits==25
  * On 64-bits, don't read more than maxNbBits==57
  * Use the fast variant *only* if n >= 1.
  * return : value extracted.
  */
 static size_t FSE_readBits(FSE_DStream_t* bitD, U32 nbBits)
 {
     size_t value = FSE_lookBits(bitD, nbBits);
     FSE_skipBits(bitD, nbBits);
     return value;
 }
 
 static size_t FSE_readBitsFast(FSE_DStream_t* bitD, U32 nbBits)   /* only if nbBits >= 1 !! */
 {
     size_t value = FSE_lookBitsFast(bitD, nbBits);
     FSE_skipBits(bitD, nbBits);
     return value;
 }
 
 static unsigned FSE_reloadDStream(FSE_DStream_t* bitD)
 {
     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
         return FSE_DStream_tooFar;
 
     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
     {
         bitD->ptr -= bitD->bitsConsumed >> 3;
         bitD->bitsConsumed &= 7;
         bitD->bitContainer = FSE_readLEST(bitD->ptr);
         return FSE_DStream_unfinished;
     }
     if (bitD->ptr == bitD->start)
     {
         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return FSE_DStream_endOfBuffer;
         return FSE_DStream_completed;
     }
     {
         U32 nbBytes = bitD->bitsConsumed >> 3;
         U32 result = FSE_DStream_unfinished;
         if (bitD->ptr - nbBytes < bitD->start)
         {
             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
             result = FSE_DStream_endOfBuffer;
         }
         bitD->ptr -= nbBytes;
         bitD->bitsConsumed -= nbBytes*8;
         bitD->bitContainer = FSE_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
         return result;
     }
 }
 
 
 static void FSE_initDState(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD, const FSE_DTable* dt)
 {
     const void* ptr = dt;
     const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr;
     DStatePtr->state = FSE_readBits(bitD, DTableH->tableLog);
     FSE_reloadDStream(bitD);
     DStatePtr->table = dt + 1;
 }
 
 static BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD)
 {
     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     const U32  nbBits = DInfo.nbBits;
     BYTE symbol = DInfo.symbol;
     size_t lowBits = FSE_readBits(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 static BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, FSE_DStream_t* bitD)
 {
     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     const U32 nbBits = DInfo.nbBits;
     BYTE symbol = DInfo.symbol;
     size_t lowBits = FSE_readBitsFast(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 /* FSE_endOfDStream
    Tells if bitD has reached end of bitStream or not */
 
 static unsigned FSE_endOfDStream(const FSE_DStream_t* bitD)
 {
     return ((bitD->ptr == bitD->start) && (bitD->bitsConsumed == sizeof(bitD->bitContainer)*8));
 }
 
 static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
 {
     return DStatePtr->state == 0;
 }
 
 
 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
           void* dst, size_t maxDstSize,
     const void* cSrc, size_t cSrcSize,
     const FSE_DTable* dt, const unsigned fast)
 {
     BYTE* const ostart = (BYTE*) dst;
     BYTE* op = ostart;
     BYTE* const omax = op + maxDstSize;
     BYTE* const olimit = omax-3;
 
     FSE_DStream_t bitD;
     FSE_DState_t state1;
     FSE_DState_t state2;
     size_t errorCode;
 
     /* Init */
     errorCode = FSE_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
     if (FSE_isError(errorCode)) return errorCode;
 
     FSE_initDState(&state1, &bitD, dt);
     FSE_initDState(&state2, &bitD, dt);
 
 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
 
     /* 4 symbols per loop */
     for ( ; (FSE_reloadDStream(&bitD)==FSE_DStream_unfinished) && (op sizeof(bitD.bitContainer)*8)    /* This test must be static */
             FSE_reloadDStream(&bitD);
 
         op[1] = FSE_GETSYMBOL(&state2);
 
         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             { if (FSE_reloadDStream(&bitD) > FSE_DStream_unfinished) { op+=2; break; } }
 
         op[2] = FSE_GETSYMBOL(&state1);
 
         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             FSE_reloadDStream(&bitD);
 
         op[3] = FSE_GETSYMBOL(&state2);
     }
 
     /* tail */
     /* note : FSE_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly FSE_DStream_completed */
     while (1)
     {
         if ( (FSE_reloadDStream(&bitD)>FSE_DStream_completed) || (op==omax) || (FSE_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
             break;
 
         *op++ = FSE_GETSYMBOL(&state1);
 
         if ( (FSE_reloadDStream(&bitD)>FSE_DStream_completed) || (op==omax) || (FSE_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
             break;
 
         *op++ = FSE_GETSYMBOL(&state2);
     }
 
     /* end ? */
     if (FSE_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
         return op-ostart;
 
     if (op==omax) return (size_t)-FSE_ERROR_dstSize_tooSmall;   /* dst buffer is full, but cSrc unfinished */
 
     return (size_t)-FSE_ERROR_corruptionDetected;
 }
 
 
 static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
                             const void* cSrc, size_t cSrcSize,
                             const FSE_DTable* dt)
 {
     FSE_DTableHeader DTableH;
     memcpy(&DTableH, dt, sizeof(DTableH));   /* memcpy() into local variable, to avoid strict aliasing warning */
 
     /* select fast mode (static) */
     if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
 }
 
 
 static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
 {
     const BYTE* const istart = (const BYTE*)cSrc;
     const BYTE* ip = istart;
     short counting[FSE_MAX_SYMBOL_VALUE+1];
     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
     unsigned tableLog;
     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
     size_t errorCode;
 
     if (cSrcSize<2) return (size_t)-FSE_ERROR_srcSize_wrong;   /* too small input size */
 
     /* normal FSE decoding mode */
     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
     if (FSE_isError(errorCode)) return errorCode;
     if (errorCode >= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong;   /* too small input size */
     ip += errorCode;
     cSrcSize -= errorCode;
 
     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
     if (FSE_isError(errorCode)) return errorCode;
 
     /* always return, even if it is an error code */
     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
 }
 
 
 
 /* *******************************************************
 *  Huff0 : Huffman block compression
 *********************************************************/
 #define HUF_MAX_SYMBOL_VALUE 255
 #define HUF_DEFAULT_TABLELOG  12       /* used by default, when not specified */
 #define HUF_MAX_TABLELOG  12           /* max possible tableLog; for allocation purpose; can be modified */
 #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
 #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
 #  error "HUF_MAX_TABLELOG is too large !"
 #endif
 
 typedef struct HUF_CElt_s {
   U16  val;
   BYTE nbBits;
 } HUF_CElt ;
 
 typedef struct nodeElt_s {
     U32 count;
     U16 parent;
     BYTE byte;
     BYTE nbBits;
 } nodeElt;
 
 
 /* *******************************************************
 *  Huff0 : Huffman block decompression
 *********************************************************/
 typedef struct {
     BYTE byte;
     BYTE nbBits;
 } HUF_DElt;
 
 static size_t HUF_readDTable (U16* DTable, const void* src, size_t srcSize)
 {
     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];  /* large enough for values from 0 to 16 */
     U32 weightTotal;
     U32 maxBits;
     const BYTE* ip = (const BYTE*) src;
     size_t iSize;
     size_t oSize;
     U32 n;
     U32 nextRankStart;
     void* ptr = DTable+1;
     HUF_DElt* const dt = (HUF_DElt*)ptr;
 
     if (!srcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
     iSize = ip[0];
 
     FSE_STATIC_ASSERT(sizeof(HUF_DElt) == sizeof(U16));   /* if compilation fails here, assertion is false */
     //memset(huffWeight, 0, sizeof(huffWeight));   /* should not be necessary, but some analyzer complain ... */
     if (iSize >= 128)  /* special header */
     {
         if (iSize >= (242))   /* RLE */
         {
             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
             oSize = l[iSize-242];
             memset(huffWeight, 1, sizeof(huffWeight));
             iSize = 0;
         }
         else   /* Incompressible */
         {
             oSize = iSize - 127;
             iSize = ((oSize+1)/2);
             if (iSize+1 > srcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
             ip += 1;
             for (n=0; n> 4;
                 huffWeight[n+1] = ip[n/2] & 15;
             }
         }
     }
     else  /* header compressed with FSE (normal case) */
     {
         if (iSize+1 > srcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
         oSize = FSE_decompress(huffWeight, HUF_MAX_SYMBOL_VALUE, ip+1, iSize);   /* max 255 values decoded, last one is implied */
         if (FSE_isError(oSize)) return oSize;
     }
 
     /* collect weight stats */
     memset(rankVal, 0, sizeof(rankVal));
     weightTotal = 0;
     for (n=0; n= HUF_ABSOLUTEMAX_TABLELOG) return (size_t)-FSE_ERROR_corruptionDetected;
         rankVal[huffWeight[n]]++;
         weightTotal += (1 << huffWeight[n]) >> 1;
     }
     if (weightTotal == 0) return (size_t)-FSE_ERROR_corruptionDetected;
 
     /* get last non-null symbol weight (implied, total must be 2^n) */
     maxBits = FSE_highbit32(weightTotal) + 1;
     if (maxBits > DTable[0]) return (size_t)-FSE_ERROR_tableLog_tooLarge;   /* DTable is too small */
     DTable[0] = (U16)maxBits;
     {
         U32 total = 1 << maxBits;
         U32 rest = total - weightTotal;
         U32 verif = 1 << FSE_highbit32(rest);
         U32 lastWeight = FSE_highbit32(rest) + 1;
         if (verif != rest) return (size_t)-FSE_ERROR_corruptionDetected;    /* last value must be a clean power of 2 */
         huffWeight[oSize] = (BYTE)lastWeight;
         rankVal[lastWeight]++;
     }
 
     /* check tree construction validity */
     if ((rankVal[1] < 2) || (rankVal[1] & 1)) return (size_t)-FSE_ERROR_corruptionDetected;   /* by construction : at least 2 elts of rank 1, must be even */
 
     /* Prepare ranks */
     nextRankStart = 0;
     for (n=1; n<=maxBits; n++)
     {
         U32 current = nextRankStart;
         nextRankStart += (rankVal[n] << (n-1));
         rankVal[n] = current;
     }
 
     /* fill DTable */
     for (n=0; n<=oSize; n++)
     {
         const U32 w = huffWeight[n];
         const U32 length = (1 << w) >> 1;
         U32 i;
         HUF_DElt D;
         D.byte = (BYTE)n; D.nbBits = (BYTE)(maxBits + 1 - w);
         for (i = rankVal[w]; i < rankVal[w] + length; i++)
             dt[i] = D;
         rankVal[w] += length;
     }
 
     return iSize+1;
 }
 
 
 static BYTE HUF_decodeSymbol(FSE_DStream_t* Dstream, const HUF_DElt* dt, const U32 dtLog)
 {
         const size_t val = FSE_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
         const BYTE c = dt[val].byte;
         FSE_skipBits(Dstream, dt[val].nbBits);
         return c;
 }
 
 static size_t HUF_decompress_usingDTable(   /* -3% slower when non static */
           void* dst, size_t maxDstSize,
     const void* cSrc, size_t cSrcSize,
     const U16* DTable)
 {
     if (cSrcSize < 6) return (size_t)-FSE_ERROR_srcSize_wrong;
     {
         BYTE* const ostart = (BYTE*) dst;
         BYTE* op = ostart;
         BYTE* const omax = op + maxDstSize;
         BYTE* const olimit = omax-15;
 
         const void* ptr = DTable;
         const HUF_DElt* const dt = (const HUF_DElt*)(ptr)+1;
         const U32 dtLog = DTable[0];
         size_t errorCode;
         U32 reloadStatus;
 
         /* Init */
 
         const U16* jumpTable = (const U16*)cSrc;
         const size_t length1 = FSE_readLE16(jumpTable);
         const size_t length2 = FSE_readLE16(jumpTable+1);
         const size_t length3 = FSE_readLE16(jumpTable+2);
         const size_t length4 = cSrcSize - 6 - length1 - length2 - length3;   // check coherency !!
         const char* const start1 = (const char*)(cSrc) + 6;
         const char* const start2 = start1 + length1;
         const char* const start3 = start2 + length2;
         const char* const start4 = start3 + length3;
         FSE_DStream_t bitD1, bitD2, bitD3, bitD4;
 
         if (length1+length2+length3+6 >= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
 
         errorCode = FSE_initDStream(&bitD1, start1, length1);
         if (FSE_isError(errorCode)) return errorCode;
         errorCode = FSE_initDStream(&bitD2, start2, length2);
         if (FSE_isError(errorCode)) return errorCode;
         errorCode = FSE_initDStream(&bitD3, start3, length3);
         if (FSE_isError(errorCode)) return errorCode;
         errorCode = FSE_initDStream(&bitD4, start4, length4);
         if (FSE_isError(errorCode)) return errorCode;
 
         reloadStatus=FSE_reloadDStream(&bitD2);
 
         /* 16 symbols per loop */
         for ( ; (reloadStatus12)) FSE_reloadDStream(&Dstream)
 
     #define HUF_DECODE_SYMBOL_2(n, Dstream) \
             op[n] = HUF_decodeSymbol(&Dstream, dt, dtLog); \
             if (FSE_32bits()) FSE_reloadDStream(&Dstream)
 
             HUF_DECODE_SYMBOL_1( 0, bitD1);
             HUF_DECODE_SYMBOL_1( 1, bitD2);
             HUF_DECODE_SYMBOL_1( 2, bitD3);
             HUF_DECODE_SYMBOL_1( 3, bitD4);
             HUF_DECODE_SYMBOL_2( 4, bitD1);
             HUF_DECODE_SYMBOL_2( 5, bitD2);
             HUF_DECODE_SYMBOL_2( 6, bitD3);
             HUF_DECODE_SYMBOL_2( 7, bitD4);
             HUF_DECODE_SYMBOL_1( 8, bitD1);
             HUF_DECODE_SYMBOL_1( 9, bitD2);
             HUF_DECODE_SYMBOL_1(10, bitD3);
             HUF_DECODE_SYMBOL_1(11, bitD4);
             HUF_DECODE_SYMBOL_0(12, bitD1);
             HUF_DECODE_SYMBOL_0(13, bitD2);
             HUF_DECODE_SYMBOL_0(14, bitD3);
             HUF_DECODE_SYMBOL_0(15, bitD4);
         }
 
         if (reloadStatus!=FSE_DStream_completed)   /* not complete : some bitStream might be FSE_DStream_unfinished */
             return (size_t)-FSE_ERROR_corruptionDetected;
 
         /* tail */
         {
             // bitTail = bitD1;   // *much* slower : -20% !??!
             FSE_DStream_t bitTail;
             bitTail.ptr = bitD1.ptr;
             bitTail.bitsConsumed = bitD1.bitsConsumed;
             bitTail.bitContainer = bitD1.bitContainer;   // required in case of FSE_DStream_endOfBuffer
             bitTail.start = start1;
             for ( ; (FSE_reloadDStream(&bitTail) < FSE_DStream_completed) && (op= cSrcSize) return (size_t)-FSE_ERROR_srcSize_wrong;
     ip += errorCode;
     cSrcSize -= errorCode;
 
     return HUF_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, DTable);
 }
 
 
 #endif   /* FSE_COMMONDEFS_ONLY */
 
 /*
     zstd - standard compression library
     Copyright (C) 2014-2015, Yann Collet.
 
     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions are
     met:
     * Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
     * Redistributions in binary form must reproduce the above
     copyright notice, this list of conditions and the following disclaimer
     in the documentation and/or other materials provided with the
     distribution.
     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - zstd source repository : https://github.com/Cyan4973/zstd
     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
 */
 
 /****************************************************************
 *  Tuning parameters
 *****************************************************************/
 /* MEMORY_USAGE :
 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 *  Increasing memory usage improves compression ratio
 *  Reduced memory usage can improve speed, due to cache effect */
 #define ZSTD_MEMORY_USAGE 17
 
 
 /**************************************
    CPU Feature Detection
 **************************************/
 /*
  * Automated efficient unaligned memory access detection
  * Based on known hardware architectures
  * This list will be updated thanks to feedbacks
  */
 #if defined(CPU_HAS_EFFICIENT_UNALIGNED_MEMORY_ACCESS) \
     || defined(__ARM_FEATURE_UNALIGNED) \
     || defined(__i386__) || defined(__x86_64__) \
     || defined(_M_IX86) || defined(_M_X64) \
     || defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_8__) \
     || (defined(_M_ARM) && (_M_ARM >= 7))
 #  define ZSTD_UNALIGNED_ACCESS 1
 #else
 #  define ZSTD_UNALIGNED_ACCESS 0
 #endif
 
 
 /********************************************************
 *  Includes
 *********************************************************/
 #include       /* calloc */
 #include       /* memcpy, memmove */
 #include        /* debug : printf */
 
 
 /********************************************************
 *  Compiler specifics
 *********************************************************/
 #ifdef __AVX2__
 #  include    /* AVX2 intrinsics */
 #endif
 
 #ifdef _MSC_VER    /* Visual Studio */
 #  include                     /* For Visual 2005 */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
 #endif
 
 
 #ifndef MEM_ACCESS_MODULE
 #define MEM_ACCESS_MODULE
 /********************************************************
 *  Basic Types
 *********************************************************/
 #if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 # include 
 typedef  uint8_t BYTE;
 typedef uint16_t U16;
 typedef  int16_t S16;
 typedef uint32_t U32;
 typedef  int32_t S32;
 typedef uint64_t U64;
 #else
 typedef unsigned char       BYTE;
 typedef unsigned short      U16;
 typedef   signed short      S16;
 typedef unsigned int        U32;
 typedef   signed int        S32;
 typedef unsigned long long  U64;
 #endif
 
 #endif   /* MEM_ACCESS_MODULE */
 
 
 /********************************************************
 *  Constants
 *********************************************************/
 static const U32 ZSTD_magicNumber = 0xFD2FB51E;   /* 3rd version : seqNb header */
 
 #define HASH_LOG (ZSTD_MEMORY_USAGE - 2)
 #define HASH_TABLESIZE (1 << HASH_LOG)
 #define HASH_MASK (HASH_TABLESIZE - 1)
 
 #define KNUTH 2654435761
 
 #define BIT7 128
 #define BIT6  64
 #define BIT5  32
 #define BIT4  16
 
 #define KB *(1 <<10)
 #define MB *(1 <<20)
 #define GB *(1U<<30)
 
 #define BLOCKSIZE (128 KB)                 /* define, for static allocation */
 
 #define WORKPLACESIZE (BLOCKSIZE*3)
 #define MINMATCH 4
 #define MLbits   7
 #define LLbits   6
 #define Offbits  5
 #define MaxML  ((1<>3];
 #else
     U32 hashTable[HASH_TABLESIZE];
 #endif
     BYTE buffer[WORKPLACESIZE];
 } cctxi_t;
 
 
 
 
 /**************************************
 *  Error Management
 **************************************/
 /* published entry point */
 unsigned ZSTDv01_isError(size_t code) { return ERR_isError(code); }
 
 
 /**************************************
 *  Tool functions
 **************************************/
 #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
 #define ZSTD_VERSION_MINOR    1    /* for new (non-breaking) interface capabilities */
 #define ZSTD_VERSION_RELEASE  3    /* for tweaks, bug-fixes, or development */
 #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
 
 /**************************************************************
 *   Decompression code
 **************************************************************/
 
 static size_t ZSTDv01_getcBlockSize(const void* src, size_t srcSize, blockProperties_t* bpPtr)
 {
     const BYTE* const in = (const BYTE* const)src;
     BYTE headerFlags;
     U32 cSize;
 
     if (srcSize < 3) return ERROR(srcSize_wrong);
 
     headerFlags = *in;
     cSize = in[2] + (in[1]<<8) + ((in[0] & 7)<<16);
 
     bpPtr->blockType = (blockType_t)(headerFlags >> 6);
     bpPtr->origSize = (bpPtr->blockType == bt_rle) ? cSize : 0;
 
     if (bpPtr->blockType == bt_end) return 0;
     if (bpPtr->blockType == bt_rle) return 1;
     return cSize;
 }
 
 
 static size_t ZSTD_copyUncompressedBlock(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     if (srcSize > maxDstSize) return ERROR(dstSize_tooSmall);
     memcpy(dst, src, srcSize);
     return srcSize;
 }
 
 
 static size_t ZSTD_decompressLiterals(void* ctx,
                                       void* dst, size_t maxDstSize,
                                 const void* src, size_t srcSize)
 {
     BYTE* op = (BYTE*)dst;
     BYTE* const oend = op + maxDstSize;
     const BYTE* ip = (const BYTE*)src;
     size_t errorCode;
     size_t litSize;
 
     /* check : minimum 2, for litSize, +1, for content */
     if (srcSize <= 3) return ERROR(corruption_detected);
 
     litSize = ip[1] + (ip[0]<<8);
     litSize += ((ip[-3] >> 3) & 7) << 16;   // mmmmh....
     op = oend - litSize;
 
     (void)ctx;
     if (litSize > maxDstSize) return ERROR(dstSize_tooSmall);
     errorCode = HUF_decompress(op, litSize, ip+2, srcSize-2);
     if (FSE_isError(errorCode)) return ERROR(GENERIC);
     return litSize;
 }
 
 
 static size_t ZSTDv01_decodeLiteralsBlock(void* ctx,
                                 void* dst, size_t maxDstSize,
                           const BYTE** litStart, size_t* litSize,
                           const void* src, size_t srcSize)
 {
     const BYTE* const istart = (const BYTE* const)src;
     const BYTE* ip = istart;
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* const oend = ostart + maxDstSize;
     blockProperties_t litbp;
 
     size_t litcSize = ZSTDv01_getcBlockSize(src, srcSize, &litbp);
     if (ZSTDv01_isError(litcSize)) return litcSize;
     if (litcSize > srcSize - ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
     ip += ZSTD_blockHeaderSize;
 
     switch(litbp.blockType)
     {
     case bt_raw:
         *litStart = ip;
         ip += litcSize;
         *litSize = litcSize;
         break;
     case bt_rle:
         {
             size_t rleSize = litbp.origSize;
             if (rleSize>maxDstSize) return ERROR(dstSize_tooSmall);
             if (!srcSize) return ERROR(srcSize_wrong);
             memset(oend - rleSize, *ip, rleSize);
             *litStart = oend - rleSize;
             *litSize = rleSize;
             ip++;
             break;
         }
     case bt_compressed:
         {
             size_t decodedLitSize = ZSTD_decompressLiterals(ctx, dst, maxDstSize, ip, litcSize);
             if (ZSTDv01_isError(decodedLitSize)) return decodedLitSize;
             *litStart = oend - decodedLitSize;
             *litSize = decodedLitSize;
             ip += litcSize;
             break;
         }
     case bt_end:
     default:
         return ERROR(GENERIC);
     }
 
     return ip-istart;
 }
 
 
 static size_t ZSTDv01_decodeSeqHeaders(int* nbSeq, const BYTE** dumpsPtr, size_t* dumpsLengthPtr,
                          FSE_DTable* DTableLL, FSE_DTable* DTableML, FSE_DTable* DTableOffb,
                          const void* src, size_t srcSize)
 {
     const BYTE* const istart = (const BYTE* const)src;
     const BYTE* ip = istart;
     const BYTE* const iend = istart + srcSize;
     U32 LLtype, Offtype, MLtype;
     U32 LLlog, Offlog, MLlog;
     size_t dumpsLength;
 
     /* check */
     if (srcSize < 5) return ERROR(srcSize_wrong);
 
     /* SeqHead */
     *nbSeq = ZSTD_readLE16(ip); ip+=2;
     LLtype  = *ip >> 6;
     Offtype = (*ip >> 4) & 3;
     MLtype  = (*ip >> 2) & 3;
     if (*ip & 2)
     {
         dumpsLength  = ip[2];
         dumpsLength += ip[1] << 8;
         ip += 3;
     }
     else
     {
         dumpsLength  = ip[1];
         dumpsLength += (ip[0] & 1) << 8;
         ip += 2;
     }
     *dumpsPtr = ip;
     ip += dumpsLength;
     *dumpsLengthPtr = dumpsLength;
 
     /* check */
     if (ip > iend-3) return ERROR(srcSize_wrong); /* min : all 3 are "raw", hence no header, but at least xxLog bits per type */
 
     /* sequences */
     {
         S16 norm[MaxML+1];    /* assumption : MaxML >= MaxLL and MaxOff */
         size_t headerSize;
 
         /* Build DTables */
         switch(LLtype)
         {
         case bt_rle :
             LLlog = 0;
             FSE_buildDTable_rle(DTableLL, *ip++); break;
         case bt_raw :
             LLlog = LLbits;
             FSE_buildDTable_raw(DTableLL, LLbits); break;
         default :
             {   U32 max = MaxLL;
                 headerSize = FSE_readNCount(norm, &max, &LLlog, ip, iend-ip);
                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
                 if (LLlog > LLFSELog) return ERROR(corruption_detected);
                 ip += headerSize;
                 FSE_buildDTable(DTableLL, norm, max, LLlog);
         }   }
 
         switch(Offtype)
         {
         case bt_rle :
             Offlog = 0;
             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
             FSE_buildDTable_rle(DTableOffb, *ip++); break;
         case bt_raw :
             Offlog = Offbits;
             FSE_buildDTable_raw(DTableOffb, Offbits); break;
         default :
             {   U32 max = MaxOff;
                 headerSize = FSE_readNCount(norm, &max, &Offlog, ip, iend-ip);
                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
                 if (Offlog > OffFSELog) return ERROR(corruption_detected);
                 ip += headerSize;
                 FSE_buildDTable(DTableOffb, norm, max, Offlog);
         }   }
 
         switch(MLtype)
         {
         case bt_rle :
             MLlog = 0;
             if (ip > iend-2) return ERROR(srcSize_wrong); /* min : "raw", hence no header, but at least xxLog bits */
             FSE_buildDTable_rle(DTableML, *ip++); break;
         case bt_raw :
             MLlog = MLbits;
             FSE_buildDTable_raw(DTableML, MLbits); break;
         default :
             {   U32 max = MaxML;
                 headerSize = FSE_readNCount(norm, &max, &MLlog, ip, iend-ip);
                 if (FSE_isError(headerSize)) return ERROR(GENERIC);
                 if (MLlog > MLFSELog) return ERROR(corruption_detected);
                 ip += headerSize;
                 FSE_buildDTable(DTableML, norm, max, MLlog);
     }   }   }
 
     return ip-istart;
 }
 
 
 typedef struct {
     size_t litLength;
     size_t offset;
     size_t matchLength;
 } seq_t;
 
 typedef struct {
     FSE_DStream_t DStream;
     FSE_DState_t stateLL;
     FSE_DState_t stateOffb;
     FSE_DState_t stateML;
     size_t prevOffset;
     const BYTE* dumps;
     const BYTE* dumpsEnd;
 } seqState_t;
 
 
 static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState)
 {
     size_t litLength;
     size_t prevOffset;
     size_t offset;
     size_t matchLength;
     const BYTE* dumps = seqState->dumps;
     const BYTE* const de = seqState->dumpsEnd;
 
     /* Literal length */
     litLength = FSE_decodeSymbol(&(seqState->stateLL), &(seqState->DStream));
     prevOffset = litLength ? seq->offset : seqState->prevOffset;
     seqState->prevOffset = seq->offset;
     if (litLength == MaxLL)
     {
         const U32 add = dumpsstateOffb), &(seqState->DStream));
         if (ZSTD_32bits()) FSE_reloadDStream(&(seqState->DStream));
         nbBits = offsetCode - 1;
         if (offsetCode==0) nbBits = 0;   /* cmove */
         offset = ((size_t)1 << (nbBits & ((sizeof(offset)*8)-1))) + FSE_readBits(&(seqState->DStream), nbBits);
         if (ZSTD_32bits()) FSE_reloadDStream(&(seqState->DStream));
         if (offsetCode==0) offset = prevOffset;
     }
 
     /* MatchLength */
     matchLength = FSE_decodeSymbol(&(seqState->stateML), &(seqState->DStream));
     if (matchLength == MaxML)
     {
         const U32 add = dumpslitLength = litLength;
     seq->offset = offset;
     seq->matchLength = matchLength;
     seqState->dumps = dumps;
 }
 
 
 static size_t ZSTD_execSequence(BYTE* op,
                                 seq_t sequence,
                                 const BYTE** litPtr, const BYTE* const litLimit,
                                 BYTE* const base, BYTE* const oend)
 {
     static const int dec32table[] = {0, 1, 2, 1, 4, 4, 4, 4};   /* added */
     static const int dec64table[] = {8, 8, 8, 7, 8, 9,10,11};   /* subtracted */
     const BYTE* const ostart = op;
     const size_t litLength = sequence.litLength;
     BYTE* const endMatch = op + litLength + sequence.matchLength;    /* risk : address space overflow (32-bits) */
     const BYTE* const litEnd = *litPtr + litLength;
 
     /* check */
     if (endMatch > oend) return ERROR(dstSize_tooSmall);   /* overwrite beyond dst buffer */
     if (litEnd > litLimit) return ERROR(corruption_detected);
     if (sequence.matchLength > (size_t)(*litPtr-op))  return ERROR(dstSize_tooSmall);    /* overwrite literal segment */
 
     /* copy Literals */
     if (((size_t)(*litPtr - op) < 8) || ((size_t)(oend-litEnd) < 8) || (op+litLength > oend-8))
         memmove(op, *litPtr, litLength);   /* overwrite risk */
     else
         ZSTD_wildcopy(op, *litPtr, litLength);
     op += litLength;
     *litPtr = litEnd;   /* update for next sequence */
 
     /* check : last match must be at a minimum distance of 8 from end of dest buffer */
     if (oend-op < 8) return ERROR(dstSize_tooSmall);
 
     /* copy Match */
     {
         const U32 overlapRisk = (((size_t)(litEnd - endMatch)) < 12);
         const BYTE* match = op - sequence.offset;            /* possible underflow at op - offset ? */
         size_t qutt = 12;
         U64 saved[2];
 
         /* check */
         if (match < base) return ERROR(corruption_detected);
         if (sequence.offset > (size_t)base) return ERROR(corruption_detected);
 
         /* save beginning of literal sequence, in case of write overlap */
         if (overlapRisk)
         {
             if ((endMatch + qutt) > oend) qutt = oend-endMatch;
             memcpy(saved, endMatch, qutt);
         }
 
         if (sequence.offset < 8)
         {
             const int dec64 = dec64table[sequence.offset];
             op[0] = match[0];
             op[1] = match[1];
             op[2] = match[2];
             op[3] = match[3];
             match += dec32table[sequence.offset];
             ZSTD_copy4(op+4, match);
             match -= dec64;
         } else { ZSTD_copy8(op, match); }
         op += 8; match += 8;
 
         if (endMatch > oend-(16-MINMATCH))
         {
             if (op < oend-8)
             {
                 ZSTD_wildcopy(op, match, (oend-8) - op);
                 match += (oend-8) - op;
                 op = oend-8;
             }
             while (opLLTable;
     U32* DTableML = dctx->MLTable;
     U32* DTableOffb = dctx->OffTable;
     BYTE* const base = (BYTE*) (dctx->base);
 
     /* Build Decoding Tables */
     errorCode = ZSTDv01_decodeSeqHeaders(&nbSeq, &dumps, &dumpsLength,
                                       DTableLL, DTableML, DTableOffb,
                                       ip, iend-ip);
     if (ZSTDv01_isError(errorCode)) return errorCode;
     ip += errorCode;
 
     /* Regen sequences */
     {
         seq_t sequence;
         seqState_t seqState;
 
         memset(&sequence, 0, sizeof(sequence));
         seqState.dumps = dumps;
         seqState.dumpsEnd = dumps + dumpsLength;
         seqState.prevOffset = 1;
         errorCode = FSE_initDStream(&(seqState.DStream), ip, iend-ip);
         if (FSE_isError(errorCode)) return ERROR(corruption_detected);
         FSE_initDState(&(seqState.stateLL), &(seqState.DStream), DTableLL);
         FSE_initDState(&(seqState.stateOffb), &(seqState.DStream), DTableOffb);
         FSE_initDState(&(seqState.stateML), &(seqState.DStream), DTableML);
 
         for ( ; (FSE_reloadDStream(&(seqState.DStream)) <= FSE_DStream_completed) && (nbSeq>0) ; )
         {
             size_t oneSeqSize;
             nbSeq--;
             ZSTD_decodeSequence(&sequence, &seqState);
             oneSeqSize = ZSTD_execSequence(op, sequence, &litPtr, litEnd, base, oend);
             if (ZSTDv01_isError(oneSeqSize)) return oneSeqSize;
             op += oneSeqSize;
         }
 
         /* check if reached exact end */
         if ( !FSE_endOfDStream(&(seqState.DStream)) ) return ERROR(corruption_detected);   /* requested too much : data is corrupted */
         if (nbSeq<0) return ERROR(corruption_detected);   /* requested too many sequences : data is corrupted */
 
         /* last literal segment */
         {
             size_t lastLLSize = litEnd - litPtr;
             if (op+lastLLSize > oend) return ERROR(dstSize_tooSmall);
             if (op != litPtr) memmove(op, litPtr, lastLLSize);
             op += lastLLSize;
         }
     }
 
     return op-ostart;
 }
 
 
 static size_t ZSTD_decompressBlock(
                             void* ctx,
                             void* dst, size_t maxDstSize,
                       const void* src, size_t srcSize)
 {
     /* blockType == blockCompressed, srcSize is trusted */
     const BYTE* ip = (const BYTE*)src;
     const BYTE* litPtr = NULL;
     size_t litSize = 0;
     size_t errorCode;
 
     /* Decode literals sub-block */
     errorCode = ZSTDv01_decodeLiteralsBlock(ctx, dst, maxDstSize, &litPtr, &litSize, src, srcSize);
     if (ZSTDv01_isError(errorCode)) return errorCode;
     ip += errorCode;
     srcSize -= errorCode;
 
     return ZSTD_decompressSequences(ctx, dst, maxDstSize, ip, srcSize, litPtr, litSize);
 }
 
 
 size_t ZSTDv01_decompressDCtx(void* ctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     const BYTE* ip = (const BYTE*)src;
     const BYTE* iend = ip + srcSize;
     BYTE* const ostart = (BYTE* const)dst;
     BYTE* op = ostart;
     BYTE* const oend = ostart + maxDstSize;
     size_t remainingSize = srcSize;
     U32 magicNumber;
     size_t errorCode=0;
     blockProperties_t blockProperties;
 
     /* Frame Header */
     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
     magicNumber = ZSTD_readBE32(src);
     if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
 
     /* Loop on each block */
     while (1)
     {
         size_t blockSize = ZSTDv01_getcBlockSize(ip, iend-ip, &blockProperties);
         if (ZSTDv01_isError(blockSize)) return blockSize;
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
         if (blockSize > remainingSize) return ERROR(srcSize_wrong);
 
         switch(blockProperties.blockType)
         {
         case bt_compressed:
             errorCode = ZSTD_decompressBlock(ctx, op, oend-op, ip, blockSize);
             break;
         case bt_raw :
             errorCode = ZSTD_copyUncompressedBlock(op, oend-op, ip, blockSize);
             break;
         case bt_rle :
             return ERROR(GENERIC);   /* not yet supported */
             break;
         case bt_end :
             /* end of frame */
             if (remainingSize) return ERROR(srcSize_wrong);
             break;
         default:
             return ERROR(GENERIC);
         }
         if (blockSize == 0) break;   /* bt_end */
 
         if (ZSTDv01_isError(errorCode)) return errorCode;
         op += errorCode;
         ip += blockSize;
         remainingSize -= blockSize;
     }
 
     return op-ostart;
 }
 
 size_t ZSTDv01_decompress(void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     dctx_t ctx;
     ctx.base = dst;
     return ZSTDv01_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
 }
 
 /* ZSTD_errorFrameSizeInfoLegacy() :
    assumes `cSize` and `dBound` are _not_ NULL */
 static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
 {
     *cSize = ret;
     *dBound = ZSTD_CONTENTSIZE_ERROR;
 }
 
 void ZSTDv01_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
     size_t nbBlocks = 0;
     U32 magicNumber;
     blockProperties_t blockProperties;
 
     /* Frame Header */
     if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) {
         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
         return;
     }
     magicNumber = ZSTD_readBE32(src);
     if (magicNumber != ZSTD_magicNumber) {
         ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
         return;
     }
     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
 
     /* Loop on each block */
     while (1)
     {
         size_t blockSize = ZSTDv01_getcBlockSize(ip, remainingSize, &blockProperties);
         if (ZSTDv01_isError(blockSize)) {
             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, blockSize);
             return;
         }
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
         if (blockSize > remainingSize) {
             ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
             return;
         }
 
         if (blockSize == 0) break;   /* bt_end */
 
         ip += blockSize;
         remainingSize -= blockSize;
         nbBlocks++;
     }
 
     *cSize = ip - (const BYTE*)src;
     *dBound = nbBlocks * BLOCKSIZE;
 }
 
 /*******************************
 *  Streaming Decompression API
 *******************************/
 
 size_t ZSTDv01_resetDCtx(ZSTDv01_Dctx* dctx)
 {
     dctx->expected = ZSTD_frameHeaderSize;
     dctx->phase = 0;
     dctx->previousDstEnd = NULL;
     dctx->base = NULL;
     return 0;
 }
 
 ZSTDv01_Dctx* ZSTDv01_createDCtx(void)
 {
     ZSTDv01_Dctx* dctx = (ZSTDv01_Dctx*)malloc(sizeof(ZSTDv01_Dctx));
     if (dctx==NULL) return NULL;
     ZSTDv01_resetDCtx(dctx);
     return dctx;
 }
 
 size_t ZSTDv01_freeDCtx(ZSTDv01_Dctx* dctx)
 {
     free(dctx);
     return 0;
 }
 
 size_t ZSTDv01_nextSrcSizeToDecompress(ZSTDv01_Dctx* dctx)
 {
     return ((dctx_t*)dctx)->expected;
 }
 
 size_t ZSTDv01_decompressContinue(ZSTDv01_Dctx* dctx, void* dst, size_t maxDstSize, const void* src, size_t srcSize)
 {
     dctx_t* ctx = (dctx_t*)dctx;
 
     /* Sanity check */
     if (srcSize != ctx->expected) return ERROR(srcSize_wrong);
     if (dst != ctx->previousDstEnd)  /* not contiguous */
         ctx->base = dst;
 
     /* Decompress : frame header */
     if (ctx->phase == 0)
     {
         /* Check frame magic header */
         U32 magicNumber = ZSTD_readBE32(src);
         if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
         ctx->phase = 1;
         ctx->expected = ZSTD_blockHeaderSize;
         return 0;
     }
 
     /* Decompress : block header */
     if (ctx->phase == 1)
     {
         blockProperties_t bp;
         size_t blockSize = ZSTDv01_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
         if (ZSTDv01_isError(blockSize)) return blockSize;
         if (bp.blockType == bt_end)
         {
             ctx->expected = 0;
             ctx->phase = 0;
         }
         else
         {
             ctx->expected = blockSize;
             ctx->bType = bp.blockType;
             ctx->phase = 2;
         }
 
         return 0;
     }
 
     /* Decompress : block content */
     {
         size_t rSize;
         switch(ctx->bType)
         {
         case bt_compressed:
             rSize = ZSTD_decompressBlock(ctx, dst, maxDstSize, src, srcSize);
             break;
         case bt_raw :
             rSize = ZSTD_copyUncompressedBlock(dst, maxDstSize, src, srcSize);
             break;
         case bt_rle :
             return ERROR(GENERIC);   /* not yet handled */
             break;
         case bt_end :   /* should never happen (filtered at phase 1) */
             rSize = 0;
             break;
         default:
             return ERROR(GENERIC);
         }
         ctx->phase = 1;
         ctx->expected = ZSTD_blockHeaderSize;
         ctx->previousDstEnd = (void*)( ((char*)dst) + rSize);
         return rSize;
     }
 
 }
Index: head/sys/contrib/zstd/lib/legacy/zstd_v02.c
===================================================================
--- head/sys/contrib/zstd/lib/legacy/zstd_v02.c	(revision 354776)
+++ head/sys/contrib/zstd/lib/legacy/zstd_v02.c	(revision 354777)
@@ -1,3513 +1,3514 @@
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under both the BSD-style license (found in the
  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
  * in the COPYING file in the root directory of this source tree).
  * You may select, at your option, one of the above-listed licenses.
  */
 
 
 #include     /* size_t, ptrdiff_t */
 #include "zstd_v02.h"
 #include "error_private.h"
 
 
 /******************************************
 *  Compiler-specific
 ******************************************/
 #if defined(_MSC_VER)   /* Visual Studio */
 #   include   /* _byteswap_ulong */
 #   include   /* _byteswap_* */
 #endif
 
 
 /* ******************************************************************
    mem.h
    low-level memory access routines
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 #ifndef MEM_H_MODULE
 #define MEM_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /******************************************
 *  Includes
 ******************************************/
 #include     /* size_t, ptrdiff_t */
 #include     /* memcpy */
 
 
 /******************************************
 *  Compiler-specific
 ******************************************/
 #if defined(__GNUC__)
 #  define MEM_STATIC static __attribute__((unused))
 #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 #  define MEM_STATIC static inline
 #elif defined(_MSC_VER)
 #  define MEM_STATIC static __inline
 #else
 #  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
 #endif
 
 
 /****************************************************************
 *  Basic Types
 *****************************************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 # include 
   typedef  uint8_t BYTE;
   typedef uint16_t U16;
   typedef  int16_t S16;
   typedef uint32_t U32;
   typedef  int32_t S32;
   typedef uint64_t U64;
   typedef  int64_t S64;
 #else
   typedef unsigned char       BYTE;
   typedef unsigned short      U16;
   typedef   signed short      S16;
   typedef unsigned int        U32;
   typedef   signed int        S32;
   typedef unsigned long long  U64;
   typedef   signed long long  S64;
 #endif
 
 
 /****************************************************************
 *  Memory I/O
 *****************************************************************/
 /* MEM_FORCE_MEMORY_ACCESS
  * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
  * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
  * The below switch allow to select different access method for improved performance.
  * Method 0 (default) : use `memcpy()`. Safe and portable.
  * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable).
  *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
  * Method 2 : direct access. This method is portable but violate C standard.
  *            It can generate buggy code on targets generating assembly depending on alignment.
  *            But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6)
  * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
  * Prefer these methods in priority order (0 > 1 > 2)
  */
 #ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
 #  if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
 #    define MEM_FORCE_MEMORY_ACCESS 2
 #  elif (defined(__INTEL_COMPILER) && !defined(WIN32)) || \
   (defined(__GNUC__) && ( defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__) ))
 #    define MEM_FORCE_MEMORY_ACCESS 1
 #  endif
 #endif
 
 MEM_STATIC unsigned MEM_32bits(void) { return sizeof(void*)==4; }
 MEM_STATIC unsigned MEM_64bits(void) { return sizeof(void*)==8; }
 
 MEM_STATIC unsigned MEM_isLittleEndian(void)
 {
     const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
     return one.c[0];
 }
 
 #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
 
 /* violates C standard on structure alignment.
 Only use if no other choice to achieve best performance on target platform */
 MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
 MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
 MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
 
 #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
 
 /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
 /* currently only defined for gcc and icc */
 typedef union { U16 u16; U32 u32; U64 u64; } __attribute__((packed)) unalign;
 
 MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign*)ptr)->u16; }
 MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign*)ptr)->u32; }
 MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign*)ptr)->u64; }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign*)memPtr)->u16 = value; }
 
 #else
 
 /* default method, safe and standard.
    can sometimes prove slower */
 
 MEM_STATIC U16 MEM_read16(const void* memPtr)
 {
     U16 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC U32 MEM_read32(const void* memPtr)
 {
     U32 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC U64 MEM_read64(const void* memPtr)
 {
     U64 val; memcpy(&val, memPtr, sizeof(val)); return val;
 }
 
 MEM_STATIC void MEM_write16(void* memPtr, U16 value)
 {
     memcpy(memPtr, &value, sizeof(value));
 }
 
 #endif // MEM_FORCE_MEMORY_ACCESS
 
 
 MEM_STATIC U16 MEM_readLE16(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read16(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U16)(p[0] + (p[1]<<8));
     }
 }
 
 MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
 {
     if (MEM_isLittleEndian())
     {
         MEM_write16(memPtr, val);
     }
     else
     {
         BYTE* p = (BYTE*)memPtr;
         p[0] = (BYTE)val;
         p[1] = (BYTE)(val>>8);
     }
 }
 
 MEM_STATIC U32 MEM_readLE24(const void* memPtr)
 {
     return MEM_readLE16(memPtr) + (((const BYTE*)memPtr)[2] << 16);
 }
 
 MEM_STATIC U32 MEM_readLE32(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read32(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U32)((U32)p[0] + ((U32)p[1]<<8) + ((U32)p[2]<<16) + ((U32)p[3]<<24));
     }
 }
 
 
 MEM_STATIC U64 MEM_readLE64(const void* memPtr)
 {
     if (MEM_isLittleEndian())
         return MEM_read64(memPtr);
     else
     {
         const BYTE* p = (const BYTE*)memPtr;
         return (U64)((U64)p[0] + ((U64)p[1]<<8) + ((U64)p[2]<<16) + ((U64)p[3]<<24)
                      + ((U64)p[4]<<32) + ((U64)p[5]<<40) + ((U64)p[6]<<48) + ((U64)p[7]<<56));
     }
 }
 
 
 MEM_STATIC size_t MEM_readLEST(const void* memPtr)
 {
     if (MEM_32bits())
         return (size_t)MEM_readLE32(memPtr);
     else
         return (size_t)MEM_readLE64(memPtr);
 }
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* MEM_H_MODULE */
 
 
 /* ******************************************************************
    bitstream
    Part of NewGen Entropy library
    header file (to include)
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 #ifndef BITSTREAM_H_MODULE
 #define BITSTREAM_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /*
 *  This API consists of small unitary functions, which highly benefit from being inlined.
 *  Since link-time-optimization is not available for all compilers,
 *  these functions are defined into a .h to be included.
 */
 
 
 /**********************************************
 *  bitStream decompression API (read backward)
 **********************************************/
 typedef struct
 {
     size_t   bitContainer;
     unsigned bitsConsumed;
     const char* ptr;
     const char* start;
 } BIT_DStream_t;
 
 typedef enum { BIT_DStream_unfinished = 0,
                BIT_DStream_endOfBuffer = 1,
                BIT_DStream_completed = 2,
                BIT_DStream_overflow = 3 } BIT_DStream_status;  /* result of BIT_reloadDStream() */
                /* 1,2,4,8 would be better for bitmap combinations, but slows down performance a bit ... :( */
 
 MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
 MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);
 
 
 /******************************************
 *  unsafe API
 ******************************************/
 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
 /* faster, but works only if nbBits >= 1 */
 
 
 
 /****************************************************************
 *  Helper functions
 ****************************************************************/
 MEM_STATIC unsigned BIT_highbit32 (U32 val)
 {
 #   if defined(_MSC_VER)   /* Visual */
     unsigned long r=0;
     _BitScanReverse ( &r, val );
     return (unsigned) r;
 #   elif defined(__GNUC__) && (__GNUC__ >= 3)   /* Use GCC Intrinsic */
-    return 31 - __builtin_clz (val);
+    return __builtin_clz (val) ^ 31;
 #   else   /* Software version */
     static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
     U32 v = val;
     unsigned r;
     v |= v >> 1;
     v |= v >> 2;
     v |= v >> 4;
     v |= v >> 8;
     v |= v >> 16;
     r = DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
     return r;
 #   endif
 }
 
 
 
 /**********************************************************
 * bitStream decoding
 **********************************************************/
 
 /*!BIT_initDStream
 *  Initialize a BIT_DStream_t.
 *  @bitD : a pointer to an already allocated BIT_DStream_t structure
 *  @srcBuffer must point at the beginning of a bitStream
 *  @srcSize must be the exact size of the bitStream
 *  @result : size of stream (== srcSize) or an errorCode if a problem is detected
 */
 MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
 {
     if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
 
     if (srcSize >=  sizeof(size_t))   /* normal case */
     {
         U32 contain32;
         bitD->start = (const char*)srcBuffer;
         bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(size_t);
         bitD->bitContainer = MEM_readLEST(bitD->ptr);
         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
     }
     else
     {
         U32 contain32;
         bitD->start = (const char*)srcBuffer;
         bitD->ptr   = bitD->start;
         bitD->bitContainer = *(const BYTE*)(bitD->start);
         switch(srcSize)
         {
             case 7: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[6]) << (sizeof(size_t)*8 - 16);
                     /* fallthrough */
             case 6: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[5]) << (sizeof(size_t)*8 - 24);
                     /* fallthrough */
             case 5: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[4]) << (sizeof(size_t)*8 - 32);
                     /* fallthrough */
             case 4: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[3]) << 24;
                     /* fallthrough */
             case 3: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[2]) << 16;
                     /* fallthrough */
             case 2: bitD->bitContainer += (size_t)(((const BYTE*)(bitD->start))[1]) <<  8;
                     /* fallthrough */
             default:;
         }
         contain32 = ((const BYTE*)srcBuffer)[srcSize-1];
         if (contain32 == 0) return ERROR(GENERIC);   /* endMark not present */
         bitD->bitsConsumed = 8 - BIT_highbit32(contain32);
         bitD->bitsConsumed += (U32)(sizeof(size_t) - srcSize)*8;
     }
 
     return srcSize;
 }
 
 MEM_STATIC size_t BIT_lookBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
     return ((bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> 1) >> ((bitMask-nbBits) & bitMask);
 }
 
 /*! BIT_lookBitsFast :
 *   unsafe version; only works only if nbBits >= 1 */
 MEM_STATIC size_t BIT_lookBitsFast(BIT_DStream_t* bitD, U32 nbBits)
 {
     const U32 bitMask = sizeof(bitD->bitContainer)*8 - 1;
     return (bitD->bitContainer << (bitD->bitsConsumed & bitMask)) >> (((bitMask+1)-nbBits) & bitMask);
 }
 
 MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     bitD->bitsConsumed += nbBits;
 }
 
 MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
 {
     size_t value = BIT_lookBits(bitD, nbBits);
     BIT_skipBits(bitD, nbBits);
     return value;
 }
 
 /*!BIT_readBitsFast :
 *  unsafe version; only works only if nbBits >= 1 */
 MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, U32 nbBits)
 {
     size_t value = BIT_lookBitsFast(bitD, nbBits);
     BIT_skipBits(bitD, nbBits);
     return value;
 }
 
 MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
 {
     if (bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))  /* should never happen */
         return BIT_DStream_overflow;
 
     if (bitD->ptr >= bitD->start + sizeof(bitD->bitContainer))
     {
         bitD->ptr -= bitD->bitsConsumed >> 3;
         bitD->bitsConsumed &= 7;
         bitD->bitContainer = MEM_readLEST(bitD->ptr);
         return BIT_DStream_unfinished;
     }
     if (bitD->ptr == bitD->start)
     {
         if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
         return BIT_DStream_completed;
     }
     {
         U32 nbBytes = bitD->bitsConsumed >> 3;
         BIT_DStream_status result = BIT_DStream_unfinished;
         if (bitD->ptr - nbBytes < bitD->start)
         {
             nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
             result = BIT_DStream_endOfBuffer;
         }
         bitD->ptr -= nbBytes;
         bitD->bitsConsumed -= nbBytes*8;
         bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD) */
         return result;
     }
 }
 
 /*! BIT_endOfDStream
 *   @return Tells if DStream has reached its exact end
 */
 MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
 {
     return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
 }
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* BITSTREAM_H_MODULE */
 /* ******************************************************************
    Error codes and messages
    Copyright (C) 2013-2015, Yann Collet
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 #ifndef ERROR_H_MODULE
 #define ERROR_H_MODULE
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /******************************************
 *  Compiler-specific
 ******************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 #  define ERR_STATIC static inline
 #elif defined(_MSC_VER)
 #  define ERR_STATIC static __inline
 #elif defined(__GNUC__)
 #  define ERR_STATIC static __attribute__((unused))
 #else
 #  define ERR_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
 #endif
 
 
 /******************************************
 *  Error Management
 ******************************************/
 #define PREFIX(name) ZSTD_error_##name
 
 #define ERROR(name) (size_t)-PREFIX(name)
 
 #define ERROR_LIST(ITEM) \
         ITEM(PREFIX(No_Error)) ITEM(PREFIX(GENERIC)) \
         ITEM(PREFIX(dstSize_tooSmall)) ITEM(PREFIX(srcSize_wrong)) \
         ITEM(PREFIX(prefix_unknown)) ITEM(PREFIX(corruption_detected)) \
         ITEM(PREFIX(tableLog_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooLarge)) ITEM(PREFIX(maxSymbolValue_tooSmall)) \
         ITEM(PREFIX(maxCode))
 
 #define ERROR_GENERATE_ENUM(ENUM) ENUM,
 typedef enum { ERROR_LIST(ERROR_GENERATE_ENUM) } ERR_codes;  /* enum is exposed, to detect & handle specific errors; compare function result to -enum value */
 
 #define ERROR_CONVERTTOSTRING(STRING) #STRING,
 #define ERROR_GENERATE_STRING(EXPR) ERROR_CONVERTTOSTRING(EXPR)
 static const char* ERR_strings[] = { ERROR_LIST(ERROR_GENERATE_STRING) };
 
 ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }
 
 ERR_STATIC const char* ERR_getErrorName(size_t code)
 {
     static const char* codeError = "Unspecified error code";
     if (ERR_isError(code)) return ERR_strings[-(int)(code)];
     return codeError;
 }
 
 
 #if defined (__cplusplus)
 }
 #endif
 
 #endif /* ERROR_H_MODULE */
 /*
 Constructor and Destructor of type FSE_CTable
     Note that its size depends on 'tableLog' and 'maxSymbolValue' */
 typedef unsigned FSE_CTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
 typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */
 
 
 /* ******************************************************************
    FSE : Finite State Entropy coder
    header file for static linking (only)
    Copyright (C) 2013-2015, Yann Collet
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 
 /******************************************
 *  Static allocation
 ******************************************/
 /* FSE buffer bounds */
 #define FSE_NCOUNTBOUND 512
 #define FSE_BLOCKBOUND(size) (size + (size>>7))
 #define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
 
 /* You can statically allocate FSE CTable/DTable as a table of unsigned using below macro */
 #define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<(maxTableLog-1)) + ((maxSymbolValue+1)*2))
 #define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<= 1 (otherwise, result will be corrupted) */
 
 
 /******************************************
 *  Implementation of inline functions
 ******************************************/
 
 /* decompression */
 
 typedef struct {
     U16 tableLog;
     U16 fastMode;
 } FSE_DTableHeader;   /* sizeof U32 */
 
 typedef struct
 {
     unsigned short newState;
     unsigned char  symbol;
     unsigned char  nbBits;
 } FSE_decode_t;   /* size == U32 */
 
 MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
 {
     FSE_DTableHeader DTableH;
     memcpy(&DTableH, dt, sizeof(DTableH));
     DStatePtr->state = BIT_readBits(bitD, DTableH.tableLog);
     BIT_reloadDStream(bitD);
     DStatePtr->table = dt + 1;
 }
 
 MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     const U32  nbBits = DInfo.nbBits;
     BYTE symbol = DInfo.symbol;
     size_t lowBits = BIT_readBits(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
 {
     const FSE_decode_t DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
     const U32 nbBits = DInfo.nbBits;
     BYTE symbol = DInfo.symbol;
     size_t lowBits = BIT_readBitsFast(bitD, nbBits);
 
     DStatePtr->state = DInfo.newState + lowBits;
     return symbol;
 }
 
 MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
 {
     return DStatePtr->state == 0;
 }
 
 
 #if defined (__cplusplus)
 }
 #endif
 /* ******************************************************************
    Huff0 : Huffman coder, part of New Generation Entropy library
    header file for static linking (only)
    Copyright (C) 2013-2015, Yann Collet
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
    You can contact the author at :
    - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
    - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /******************************************
 *  Static allocation macros
 ******************************************/
 /* Huff0 buffer bounds */
 #define HUF_CTABLEBOUND 129
 #define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true if incompressible pre-filtered with fast heuristic */
 #define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */
 
 /* static allocation of Huff0's DTable */
 #define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<   /* size_t */
 
 
 /* *************************************
 *  Version
 ***************************************/
 #define ZSTD_VERSION_MAJOR    0    /* for breaking interface changes  */
 #define ZSTD_VERSION_MINOR    2    /* for new (non-breaking) interface capabilities */
 #define ZSTD_VERSION_RELEASE  2    /* for tweaks, bug-fixes, or development */
 #define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
 
 
 /* *************************************
 *  Advanced functions
 ***************************************/
 typedef struct ZSTD_CCtx_s ZSTD_CCtx;   /* incomplete type */
 
 #if defined (__cplusplus)
 }
 #endif
 /*
     zstd - standard compression library
     Header File for static linking only
     Copyright (C) 2014-2015, Yann Collet.
 
     BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions are
     met:
     * Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.
     * Redistributions in binary form must reproduce the above
     copyright notice, this list of conditions and the following disclaimer
     in the documentation and/or other materials provided with the
     distribution.
     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - zstd source repository : https://github.com/Cyan4973/zstd
     - ztsd public forum : https://groups.google.com/forum/#!forum/lz4c
 */
 
 /* The objects defined into this file should be considered experimental.
  * They are not labelled stable, as their prototype may change in the future.
  * You can use them for tests, provide feedback, or if you can endure risk of future changes.
  */
 
 #if defined (__cplusplus)
 extern "C" {
 #endif
 
 /* *************************************
 *  Streaming functions
 ***************************************/
 
 typedef struct ZSTD_DCtx_s ZSTD_DCtx;
 
 /*
   Use above functions alternatively.
   ZSTD_nextSrcSizeToDecompress() tells how much bytes to provide as 'srcSize' to ZSTD_decompressContinue().
   ZSTD_decompressContinue() will use previous data blocks to improve compression if they are located prior to current block.
   Result is the number of bytes regenerated within 'dst'.
   It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some header.
 */
 
 /* *************************************
 *  Prefix - version detection
 ***************************************/
 #define ZSTD_magicNumber 0xFD2FB522   /* v0.2 (current)*/
 
 
 #if defined (__cplusplus)
 }
 #endif
 /* ******************************************************************
    FSE : Finite State Entropy coder
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 #ifndef FSE_COMMONDEFS_ONLY
 
 /****************************************************************
 *  Tuning parameters
 ****************************************************************/
 /* MEMORY_USAGE :
 *  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
 *  Increasing memory usage improves compression ratio
 *  Reduced memory usage can improve speed, due to cache effect
 *  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
 #define FSE_MAX_MEMORY_USAGE 14
 #define FSE_DEFAULT_MEMORY_USAGE 13
 
 /* FSE_MAX_SYMBOL_VALUE :
 *  Maximum symbol value authorized.
 *  Required for proper stack allocation */
 #define FSE_MAX_SYMBOL_VALUE 255
 
 
 /****************************************************************
 *  template functions type & suffix
 ****************************************************************/
 #define FSE_FUNCTION_TYPE BYTE
 #define FSE_FUNCTION_EXTENSION
 
 
 /****************************************************************
 *  Byte symbol type
 ****************************************************************/
 #endif   /* !FSE_COMMONDEFS_ONLY */
 
 
 /****************************************************************
 *  Compiler specifics
 ****************************************************************/
 #ifdef _MSC_VER    /* Visual Studio */
 #  define FORCE_INLINE static __forceinline
 #  include                     /* For Visual 2005 */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
 #else
 #  if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
 #    ifdef __GNUC__
 #      define FORCE_INLINE static inline __attribute__((always_inline))
 #    else
 #      define FORCE_INLINE static inline
 #    endif
 #  else
 #    define FORCE_INLINE static
 #  endif /* __STDC_VERSION__ */
 #endif
 
 
 /****************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
 #include       /* printf (debug) */
 
 /****************************************************************
 *  Constants
 *****************************************************************/
 #define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
 #define FSE_MAX_TABLESIZE (1U< FSE_TABLELOG_ABSOLUTE_MAX
 #error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
 #endif
 
 
 /****************************************************************
 *  Error Management
 ****************************************************************/
 #define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
 /****************************************************************
 *  Complex types
 ****************************************************************/
 typedef U32 DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
 
 
 /****************************************************************
 *  Templates
 ****************************************************************/
 /*
   designed to be included
   for type-specific functions (template emulation in C)
   Objective is to write these functions only once, for improved maintenance
 */
 
 /* safety checks */
 #ifndef FSE_FUNCTION_EXTENSION
 #  error "FSE_FUNCTION_EXTENSION must be defined"
 #endif
 #ifndef FSE_FUNCTION_TYPE
 #  error "FSE_FUNCTION_TYPE must be defined"
 #endif
 
 /* Function names */
 #define FSE_CAT(X,Y) X##Y
 #define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
 #define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
 
 
 /* Function templates */
 
 #define FSE_DECODE_TYPE FSE_decode_t
 
 static U32 FSE_tableStep(U32 tableSize) { return (tableSize>>1) + (tableSize>>3) + 3; }
 
 static size_t FSE_buildDTable
 (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
 {
     void* ptr = dt+1;
     FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*)ptr;
     FSE_DTableHeader DTableH;
     const U32 tableSize = 1 << tableLog;
     const U32 tableMask = tableSize-1;
     const U32 step = FSE_tableStep(tableSize);
     U16 symbolNext[FSE_MAX_SYMBOL_VALUE+1];
     U32 position = 0;
     U32 highThreshold = tableSize-1;
     const S16 largeLimit= (S16)(1 << (tableLog-1));
     U32 noLarge = 1;
     U32 s;
 
     /* Sanity Checks */
     if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
     if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
 
     /* Init, lay down lowprob symbols */
     DTableH.tableLog = (U16)tableLog;
     for (s=0; s<=maxSymbolValue; s++)
     {
         if (normalizedCounter[s]==-1)
         {
             tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
             symbolNext[s] = 1;
         }
         else
         {
             if (normalizedCounter[s] >= largeLimit) noLarge=0;
             symbolNext[s] = normalizedCounter[s];
         }
     }
 
     /* Spread symbols */
     for (s=0; s<=maxSymbolValue; s++)
     {
         int i;
         for (i=0; i highThreshold) position = (position + step) & tableMask;   /* lowprob area */
         }
     }
 
     if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
 
     /* Build Decoding table */
     {
         U32 i;
         for (i=0; i FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
     bitStream >>= 4;
     bitCount = 4;
     *tableLogPtr = nbBits;
     remaining = (1<1) && (charnum<=*maxSVPtr))
     {
         if (previous0)
         {
             unsigned n0 = charnum;
             while ((bitStream & 0xFFFF) == 0xFFFF)
             {
                 n0+=24;
                 if (ip < iend-5)
                 {
                     ip+=2;
                     bitStream = MEM_readLE32(ip) >> bitCount;
                 }
                 else
                 {
                     bitStream >>= 16;
                     bitCount+=16;
                 }
             }
             while ((bitStream & 3) == 3)
             {
                 n0+=3;
                 bitStream>>=2;
                 bitCount+=2;
             }
             n0 += bitStream & 3;
             bitCount += 2;
             if (n0 > *maxSVPtr) return ERROR(maxSymbolValue_tooSmall);
             while (charnum < n0) normalizedCounter[charnum++] = 0;
             if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
             {
                 ip += bitCount>>3;
                 bitCount &= 7;
                 bitStream = MEM_readLE32(ip) >> bitCount;
             }
             else
                 bitStream >>= 2;
         }
         {
             const short max = (short)((2*threshold-1)-remaining);
             short count;
 
             if ((bitStream & (threshold-1)) < (U32)max)
             {
                 count = (short)(bitStream & (threshold-1));
                 bitCount   += nbBits-1;
             }
             else
             {
                 count = (short)(bitStream & (2*threshold-1));
                 if (count >= threshold) count -= max;
                 bitCount   += nbBits;
             }
 
             count--;   /* extra accuracy */
             remaining -= FSE_abs(count);
             normalizedCounter[charnum++] = count;
             previous0 = !count;
             while (remaining < threshold)
             {
                 nbBits--;
                 threshold >>= 1;
             }
 
             {
                 if ((ip <= iend-7) || (ip + (bitCount>>3) <= iend-4))
                 {
                     ip += bitCount>>3;
                     bitCount &= 7;
                 }
                 else
                 {
                     bitCount -= (int)(8 * (iend - 4 - ip));
                     ip = iend - 4;
                 }
                 bitStream = MEM_readLE32(ip) >> (bitCount & 31);
             }
         }
     }
     if (remaining != 1) return ERROR(GENERIC);
     *maxSVPtr = charnum-1;
 
     ip += (bitCount+7)>>3;
     if ((size_t)(ip-istart) > hbSize) return ERROR(srcSize_wrong);
     return ip-istart;
 }
 
 
 /*********************************************************
 *  Decompression (Byte symbols)
 *********************************************************/
 static size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_decode_t* const cell = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
 
     DTableH->tableLog = 0;
     DTableH->fastMode = 0;
 
     cell->newState = 0;
     cell->symbol = symbolValue;
     cell->nbBits = 0;
 
     return 0;
 }
 
 
 static size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
 {
     void* ptr = dt;
     FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
     FSE_decode_t* const dinfo = (FSE_decode_t*)(ptr) + 1;   /* because dt is unsigned */
     const unsigned tableSize = 1 << nbBits;
     const unsigned tableMask = tableSize - 1;
     const unsigned maxSymbolValue = tableMask;
     unsigned s;
 
     /* Sanity checks */
     if (nbBits < 1) return ERROR(GENERIC);         /* min size */
 
     /* Build Decoding Table */
     DTableH->tableLog = (U16)nbBits;
     DTableH->fastMode = 1;
     for (s=0; s<=maxSymbolValue; s++)
     {
         dinfo[s].newState = 0;
         dinfo[s].symbol = (BYTE)s;
         dinfo[s].nbBits = (BYTE)nbBits;
     }
 
     return 0;
 }
 
 FORCE_INLINE size_t FSE_decompress_usingDTable_generic(
           void* dst, size_t maxDstSize,
     const void* cSrc, size_t cSrcSize,
     const FSE_DTable* dt, const unsigned fast)
 {
     BYTE* const ostart = (BYTE*) dst;
     BYTE* op = ostart;
     BYTE* const omax = op + maxDstSize;
     BYTE* const olimit = omax-3;
 
     BIT_DStream_t bitD;
     FSE_DState_t state1;
     FSE_DState_t state2;
     size_t errorCode;
 
     /* Init */
     errorCode = BIT_initDStream(&bitD, cSrc, cSrcSize);   /* replaced last arg by maxCompressed Size */
     if (FSE_isError(errorCode)) return errorCode;
 
     FSE_initDState(&state1, &bitD, dt);
     FSE_initDState(&state2, &bitD, dt);
 
 #define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
 
     /* 4 symbols per loop */
     for ( ; (BIT_reloadDStream(&bitD)==BIT_DStream_unfinished) && (op sizeof(bitD.bitContainer)*8)    /* This test must be static */
             BIT_reloadDStream(&bitD);
 
         op[1] = FSE_GETSYMBOL(&state2);
 
         if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }
 
         op[2] = FSE_GETSYMBOL(&state1);
 
         if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
             BIT_reloadDStream(&bitD);
 
         op[3] = FSE_GETSYMBOL(&state2);
     }
 
     /* tail */
     /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
     while (1)
     {
         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state1))) )
             break;
 
         *op++ = FSE_GETSYMBOL(&state1);
 
         if ( (BIT_reloadDStream(&bitD)>BIT_DStream_completed) || (op==omax) || (BIT_endOfDStream(&bitD) && (fast || FSE_endOfDState(&state2))) )
             break;
 
         *op++ = FSE_GETSYMBOL(&state2);
     }
 
     /* end ? */
     if (BIT_endOfDStream(&bitD) && FSE_endOfDState(&state1) && FSE_endOfDState(&state2))
         return op-ostart;
 
     if (op==omax) return ERROR(dstSize_tooSmall);   /* dst buffer is full, but cSrc unfinished */
 
     return ERROR(corruption_detected);
 }
 
 
 static size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
                             const void* cSrc, size_t cSrcSize,
                             const FSE_DTable* dt)
 {
     FSE_DTableHeader DTableH;
     memcpy(&DTableH, dt, sizeof(DTableH));
 
     /* select fast mode (static) */
     if (DTableH.fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
     return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
 }
 
 
 static size_t FSE_decompress(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize)
 {
     const BYTE* const istart = (const BYTE*)cSrc;
     const BYTE* ip = istart;
     short counting[FSE_MAX_SYMBOL_VALUE+1];
     DTable_max_t dt;   /* Static analyzer seems unable to understand this table will be properly initialized later */
     unsigned tableLog;
     unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
     size_t errorCode;
 
     if (cSrcSize<2) return ERROR(srcSize_wrong);   /* too small input size */
 
     /* normal FSE decoding mode */
     errorCode = FSE_readNCount (counting, &maxSymbolValue, &tableLog, istart, cSrcSize);
     if (FSE_isError(errorCode)) return errorCode;
     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);   /* too small input size */
     ip += errorCode;
     cSrcSize -= errorCode;
 
     errorCode = FSE_buildDTable (dt, counting, maxSymbolValue, tableLog);
     if (FSE_isError(errorCode)) return errorCode;
 
     /* always return, even if it is an error code */
     return FSE_decompress_usingDTable (dst, maxDstSize, ip, cSrcSize, dt);
 }
 
 
 
 #endif   /* FSE_COMMONDEFS_ONLY */
 /* ******************************************************************
    Huff0 : Huffman coder, part of New Generation Entropy library
    Copyright (C) 2013-2015, Yann Collet.
 
    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:
 
        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
     You can contact the author at :
     - FSE+Huff0 source repository : https://github.com/Cyan4973/FiniteStateEntropy
     - Public forum : https://groups.google.com/forum/#!forum/lz4c
 ****************************************************************** */
 
 /****************************************************************
 *  Compiler specifics
 ****************************************************************/
 #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
 /* inline is defined */
 #elif defined(_MSC_VER)
 #  define inline __inline
 #else
 #  define inline /* disable inline */
 #endif
 
 
 #ifdef _MSC_VER    /* Visual Studio */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #endif
 
 
 /****************************************************************
 *  Includes
 ****************************************************************/
 #include      /* malloc, free, qsort */
 #include      /* memcpy, memset */
 #include       /* printf (debug) */
 
 /****************************************************************
 *  Error Management
 ****************************************************************/
 #define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; }   /* use only *after* variable declarations */
 
 
 /******************************************
 *  Helper functions
 ******************************************/
 static unsigned HUF_isError(size_t code) { return ERR_isError(code); }
 
 #define HUF_ABSOLUTEMAX_TABLELOG  16   /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
 #define HUF_MAX_TABLELOG  12           /* max configured tableLog (for static allocation); can be modified up to HUF_ABSOLUTEMAX_TABLELOG */
 #define HUF_DEFAULT_TABLELOG  HUF_MAX_TABLELOG   /* tableLog by default, when not specified */
 #define HUF_MAX_SYMBOL_VALUE 255
 #if (HUF_MAX_TABLELOG > HUF_ABSOLUTEMAX_TABLELOG)
 #  error "HUF_MAX_TABLELOG is too large !"
 #endif
 
 
 
 /*********************************************************
 *  Huff0 : Huffman block decompression
 *********************************************************/
 typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX2;   /* single-symbol decoding */
 
 typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX4;  /* double-symbols decoding */
 
 typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
 
 /*! HUF_readStats
     Read compact Huffman tree, saved by HUF_writeCTable
     @huffWeight : destination buffer
     @return : size read from `src`
 */
 static size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
                             U32* nbSymbolsPtr, U32* tableLogPtr,
                             const void* src, size_t srcSize)
 {
     U32 weightTotal;
     U32 tableLog;
     const BYTE* ip = (const BYTE*) src;
     size_t iSize;
     size_t oSize;
     U32 n;
 
     if (!srcSize) return ERROR(srcSize_wrong);
     iSize = ip[0];
     //memset(huffWeight, 0, hwSize);   /* is not necessary, even though some analyzer complain ... */
 
     if (iSize >= 128)  /* special header */
     {
         if (iSize >= (242))   /* RLE */
         {
             static int l[14] = { 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128 };
             oSize = l[iSize-242];
             memset(huffWeight, 1, hwSize);
             iSize = 0;
         }
         else   /* Incompressible */
         {
             oSize = iSize - 127;
             iSize = ((oSize+1)/2);
             if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
             if (oSize >= hwSize) return ERROR(corruption_detected);
             ip += 1;
             for (n=0; n> 4;
                 huffWeight[n+1] = ip[n/2] & 15;
             }
         }
     }
     else  /* header compressed with FSE (normal case) */
     {
         if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
         oSize = FSE_decompress(huffWeight, hwSize-1, ip+1, iSize);   /* max (hwSize-1) values decoded, as last one is implied */
         if (FSE_isError(oSize)) return oSize;
     }
 
     /* collect weight stats */
     memset(rankStats, 0, (HUF_ABSOLUTEMAX_TABLELOG + 1) * sizeof(U32));
     weightTotal = 0;
     for (n=0; n= HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
         rankStats[huffWeight[n]]++;
         weightTotal += (1 << huffWeight[n]) >> 1;
     }
     if (weightTotal == 0) return ERROR(corruption_detected);
 
     /* get last non-null symbol weight (implied, total must be 2^n) */
     tableLog = BIT_highbit32(weightTotal) + 1;
     if (tableLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(corruption_detected);
     {
         U32 total = 1 << tableLog;
         U32 rest = total - weightTotal;
         U32 verif = 1 << BIT_highbit32(rest);
         U32 lastWeight = BIT_highbit32(rest) + 1;
         if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
         huffWeight[oSize] = (BYTE)lastWeight;
         rankStats[lastWeight]++;
     }
 
     /* check tree construction validity */
     if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */
 
     /* results */
     *nbSymbolsPtr = (U32)(oSize+1);
     *tableLogPtr = tableLog;
     return iSize+1;
 }
 
 
 /**************************/
 /* single-symbol decoding */
 /**************************/
 
 static size_t HUF_readDTableX2 (U16* DTable, const void* src, size_t srcSize)
 {
     BYTE huffWeight[HUF_MAX_SYMBOL_VALUE + 1];
     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];   /* large enough for values from 0 to 16 */
     U32 tableLog = 0;
     const BYTE* ip = (const BYTE*) src;
     size_t iSize = ip[0];
     U32 nbSymbols = 0;
     U32 n;
     U32 nextRankStart;
     void* ptr = DTable+1;
     HUF_DEltX2* const dt = (HUF_DEltX2*)ptr;
 
     HUF_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U16));   /* if compilation fails here, assertion is false */
     //memset(huffWeight, 0, sizeof(huffWeight));   /* is not necessary, even though some analyzer complain ... */
 
     iSize = HUF_readStats(huffWeight, HUF_MAX_SYMBOL_VALUE + 1, rankVal, &nbSymbols, &tableLog, src, srcSize);
     if (HUF_isError(iSize)) return iSize;
 
     /* check result */
     if (tableLog > DTable[0]) return ERROR(tableLog_tooLarge);   /* DTable is too small */
     DTable[0] = (U16)tableLog;   /* maybe should separate sizeof DTable, as allocated, from used size of DTable, in case of DTable re-use */
 
     /* Prepare ranks */
     nextRankStart = 0;
     for (n=1; n<=tableLog; n++)
     {
         U32 current = nextRankStart;
         nextRankStart += (rankVal[n] << (n-1));
         rankVal[n] = current;
     }
 
     /* fill DTable */
     for (n=0; n> 1;
         U32 i;
         HUF_DEltX2 D;
         D.byte = (BYTE)n; D.nbBits = (BYTE)(tableLog + 1 - w);
         for (i = rankVal[w]; i < rankVal[w] + length; i++)
             dt[i] = D;
         rankVal[w] += length;
     }
 
     return iSize;
 }
 
 static BYTE HUF_decodeSymbolX2(BIT_DStream_t* Dstream, const HUF_DEltX2* dt, const U32 dtLog)
 {
         const size_t val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
         const BYTE c = dt[val].byte;
         BIT_skipBits(Dstream, dt[val].nbBits);
         return c;
 }
 
 #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
     *ptr++ = HUF_decodeSymbolX2(DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \
     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
 
 #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \
     if (MEM_64bits()) \
         HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr)
 
 static inline size_t HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog)
 {
     BYTE* const pStart = p;
 
     /* up to 4 symbols at a time */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-4))
     {
         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
     }
 
     /* closer to the end */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd))
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
 
     /* no more data to retrieve from bitstream, hence no need to reload */
     while (p < pEnd)
         HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
 
     return pEnd-pStart;
 }
 
 
 static size_t HUF_decompress4X2_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const U16* DTable)
 {
     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
 
     {
         const BYTE* const istart = (const BYTE*) cSrc;
         BYTE* const ostart = (BYTE*) dst;
         BYTE* const oend = ostart + dstSize;
 
         const void* ptr = DTable;
         const HUF_DEltX2* const dt = ((const HUF_DEltX2*)ptr) +1;
         const U32 dtLog = DTable[0];
         size_t errorCode;
 
         /* Init */
         BIT_DStream_t bitD1;
         BIT_DStream_t bitD2;
         BIT_DStream_t bitD3;
         BIT_DStream_t bitD4;
         const size_t length1 = MEM_readLE16(istart);
         const size_t length2 = MEM_readLE16(istart+2);
         const size_t length3 = MEM_readLE16(istart+4);
         size_t length4;
         const BYTE* const istart1 = istart + 6;  /* jumpTable */
         const BYTE* const istart2 = istart1 + length1;
         const BYTE* const istart3 = istart2 + length2;
         const BYTE* const istart4 = istart3 + length3;
         const size_t segmentSize = (dstSize+3) / 4;
         BYTE* const opStart2 = ostart + segmentSize;
         BYTE* const opStart3 = opStart2 + segmentSize;
         BYTE* const opStart4 = opStart3 + segmentSize;
         BYTE* op1 = ostart;
         BYTE* op2 = opStart2;
         BYTE* op3 = opStart3;
         BYTE* op4 = opStart4;
         U32 endSignal;
 
         length4 = cSrcSize - (length1 + length2 + length3 + 6);
         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
         errorCode = BIT_initDStream(&bitD1, istart1, length1);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD2, istart2, length2);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD3, istart3, length3);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD4, istart4, length4);
         if (HUF_isError(errorCode)) return errorCode;
 
         /* 16-32 symbols per loop (4-8 symbols per stream) */
         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
         {
             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
             HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
             HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
             HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
 
             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         }
 
         /* check corruption */
         if (op1 > opStart2) return ERROR(corruption_detected);
         if (op2 > opStart3) return ERROR(corruption_detected);
         if (op3 > opStart4) return ERROR(corruption_detected);
         /* note : op4 supposed already verified within main loop */
 
         /* finish bitStreams one by one */
         HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
         HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
         HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
         HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);
 
         /* check */
         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
         if (!endSignal) return ERROR(corruption_detected);
 
         /* decoded size */
         return dstSize;
     }
 }
 
 
 static size_t HUF_decompress4X2 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     HUF_CREATE_STATIC_DTABLEX2(DTable, HUF_MAX_TABLELOG);
     const BYTE* ip = (const BYTE*) cSrc;
     size_t errorCode;
 
     errorCode = HUF_readDTableX2 (DTable, cSrc, cSrcSize);
     if (HUF_isError(errorCode)) return errorCode;
     if (errorCode >= cSrcSize) return ERROR(srcSize_wrong);
     ip += errorCode;
     cSrcSize -= errorCode;
 
     return HUF_decompress4X2_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
 }
 
 
 /***************************/
 /* double-symbols decoding */
 /***************************/
 
 static void HUF_fillDTableX4Level2(HUF_DEltX4* DTable, U32 sizeLog, const U32 consumed,
                            const U32* rankValOrigin, const int minWeight,
                            const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
                            U32 nbBitsBaseline, U16 baseSeq)
 {
     HUF_DEltX4 DElt;
     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
     U32 s;
 
     /* get pre-calculated rankVal */
     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
 
     /* fill skipped values */
     if (minWeight>1)
     {
         U32 i, skipSize = rankVal[minWeight];
         MEM_writeLE16(&(DElt.sequence), baseSeq);
         DElt.nbBits   = (BYTE)(consumed);
         DElt.length   = 1;
         for (i = 0; i < skipSize; i++)
             DTable[i] = DElt;
     }
 
     /* fill DTable */
     for (s=0; s= 1 */
 
         rankVal[weight] += length;
     }
 }
 
 typedef U32 rankVal_t[HUF_ABSOLUTEMAX_TABLELOG][HUF_ABSOLUTEMAX_TABLELOG + 1];
 
 static void HUF_fillDTableX4(HUF_DEltX4* DTable, const U32 targetLog,
                            const sortedSymbol_t* sortedList, const U32 sortedListSize,
                            const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
                            const U32 nbBitsBaseline)
 {
     U32 rankVal[HUF_ABSOLUTEMAX_TABLELOG + 1];
     const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
     const U32 minBits  = nbBitsBaseline - maxWeight;
     U32 s;
 
     memcpy(rankVal, rankValOrigin, sizeof(rankVal));
 
     /* fill DTable */
     for (s=0; s= minBits)   /* enough room for a second symbol */
         {
             U32 sortedRank;
             int minWeight = nbBits + scaleLog;
             if (minWeight < 1) minWeight = 1;
             sortedRank = rankStart[minWeight];
             HUF_fillDTableX4Level2(DTable+start, targetLog-nbBits, nbBits,
                            rankValOrigin[nbBits], minWeight,
                            sortedList+sortedRank, sortedListSize-sortedRank,
                            nbBitsBaseline, symbol);
         }
         else
         {
             U32 i;
             const U32 end = start + length;
             HUF_DEltX4 DElt;
 
             MEM_writeLE16(&(DElt.sequence), symbol);
             DElt.nbBits   = (BYTE)(nbBits);
             DElt.length   = 1;
             for (i = start; i < end; i++)
                 DTable[i] = DElt;
         }
         rankVal[weight] += length;
     }
 }
 
 static size_t HUF_readDTableX4 (U32* DTable, const void* src, size_t srcSize)
 {
     BYTE weightList[HUF_MAX_SYMBOL_VALUE + 1];
     sortedSymbol_t sortedSymbol[HUF_MAX_SYMBOL_VALUE + 1];
     U32 rankStats[HUF_ABSOLUTEMAX_TABLELOG + 1] = { 0 };
     U32 rankStart0[HUF_ABSOLUTEMAX_TABLELOG + 2] = { 0 };
     U32* const rankStart = rankStart0+1;
     rankVal_t rankVal;
     U32 tableLog, maxW, sizeOfSort, nbSymbols;
     const U32 memLog = DTable[0];
     const BYTE* ip = (const BYTE*) src;
     size_t iSize = ip[0];
     void* ptr = DTable;
     HUF_DEltX4* const dt = ((HUF_DEltX4*)ptr) + 1;
 
     HUF_STATIC_ASSERT(sizeof(HUF_DEltX4) == sizeof(U32));   /* if compilation fails here, assertion is false */
     if (memLog > HUF_ABSOLUTEMAX_TABLELOG) return ERROR(tableLog_tooLarge);
     //memset(weightList, 0, sizeof(weightList));   /* is not necessary, even though some analyzer complain ... */
 
     iSize = HUF_readStats(weightList, HUF_MAX_SYMBOL_VALUE + 1, rankStats, &nbSymbols, &tableLog, src, srcSize);
     if (HUF_isError(iSize)) return iSize;
 
     /* check result */
     if (tableLog > memLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
 
     /* find maxWeight */
     for (maxW = tableLog; rankStats[maxW]==0; maxW--)
         {if (!maxW) return ERROR(GENERIC); }  /* necessarily finds a solution before maxW==0 */
 
     /* Get start index of each weight */
     {
         U32 w, nextRankStart = 0;
         for (w=1; w<=maxW; w++)
         {
             U32 current = nextRankStart;
             nextRankStart += rankStats[w];
             rankStart[w] = current;
         }
         rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
         sizeOfSort = nextRankStart;
     }
 
     /* sort symbols by weight */
     {
         U32 s;
         for (s=0; s> consumed;
             }
         }
     }
 
     HUF_fillDTableX4(dt, memLog,
                    sortedSymbol, sizeOfSort,
                    rankStart0, rankVal, maxW,
                    tableLog+1);
 
     return iSize;
 }
 
 
 static U32 HUF_decodeSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
 {
     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
     memcpy(op, dt+val, 2);
     BIT_skipBits(DStream, dt[val].nbBits);
     return dt[val].length;
 }
 
 static U32 HUF_decodeLastSymbolX4(void* op, BIT_DStream_t* DStream, const HUF_DEltX4* dt, const U32 dtLog)
 {
     const size_t val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
     memcpy(op, dt+val, 1);
     if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
     else
     {
         if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8))
         {
             BIT_skipBits(DStream, dt[val].nbBits);
             if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
                 DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8);   /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */
         }
     }
     return 1;
 }
 
 
 #define HUF_DECODE_SYMBOLX4_0(ptr, DStreamPtr) \
     ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX4_1(ptr, DStreamPtr) \
     if (MEM_64bits() || (HUF_MAX_TABLELOG<=12)) \
         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
 
 #define HUF_DECODE_SYMBOLX4_2(ptr, DStreamPtr) \
     if (MEM_64bits()) \
         ptr += HUF_decodeSymbolX4(ptr, DStreamPtr, dt, dtLog)
 
 static inline size_t HUF_decodeStreamX4(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const HUF_DEltX4* const dt, const U32 dtLog)
 {
     BYTE* const pStart = p;
 
     /* up to 8 symbols at a time */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p < pEnd-7))
     {
         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX4_1(p, bitDPtr);
         HUF_DECODE_SYMBOLX4_2(p, bitDPtr);
         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
     }
 
     /* closer to the end */
     while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) && (p <= pEnd-2))
         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);
 
     while (p <= pEnd-2)
         HUF_DECODE_SYMBOLX4_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
 
     if (p < pEnd)
         p += HUF_decodeLastSymbolX4(p, bitDPtr, dt, dtLog);
 
     return p-pStart;
 }
 
 
 
 static size_t HUF_decompress4X4_usingDTable(
           void* dst,  size_t dstSize,
     const void* cSrc, size_t cSrcSize,
     const U32* DTable)
 {
     if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
 
     {
         const BYTE* const istart = (const BYTE*) cSrc;
         BYTE* const ostart = (BYTE*) dst;
         BYTE* const oend = ostart + dstSize;
 
         const void* ptr = DTable;
         const HUF_DEltX4* const dt = ((const HUF_DEltX4*)ptr) +1;
         const U32 dtLog = DTable[0];
         size_t errorCode;
 
         /* Init */
         BIT_DStream_t bitD1;
         BIT_DStream_t bitD2;
         BIT_DStream_t bitD3;
         BIT_DStream_t bitD4;
         const size_t length1 = MEM_readLE16(istart);
         const size_t length2 = MEM_readLE16(istart+2);
         const size_t length3 = MEM_readLE16(istart+4);
         size_t length4;
         const BYTE* const istart1 = istart + 6;  /* jumpTable */
         const BYTE* const istart2 = istart1 + length1;
         const BYTE* const istart3 = istart2 + length2;
         const BYTE* const istart4 = istart3 + length3;
         const size_t segmentSize = (dstSize+3) / 4;
         BYTE* const opStart2 = ostart + segmentSize;
         BYTE* const opStart3 = opStart2 + segmentSize;
         BYTE* const opStart4 = opStart3 + segmentSize;
         BYTE* op1 = ostart;
         BYTE* op2 = opStart2;
         BYTE* op3 = opStart3;
         BYTE* op4 = opStart4;
         U32 endSignal;
 
         length4 = cSrcSize - (length1 + length2 + length3 + 6);
         if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
         errorCode = BIT_initDStream(&bitD1, istart1, length1);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD2, istart2, length2);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD3, istart3, length3);
         if (HUF_isError(errorCode)) return errorCode;
         errorCode = BIT_initDStream(&bitD4, istart4, length4);
         if (HUF_isError(errorCode)) return errorCode;
 
         /* 16-32 symbols per loop (4-8 symbols per stream) */
         endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         for ( ; (endSignal==BIT_DStream_unfinished) && (op4<(oend-7)) ; )
         {
             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX4_1(op1, &bitD1);
             HUF_DECODE_SYMBOLX4_1(op2, &bitD2);
             HUF_DECODE_SYMBOLX4_1(op3, &bitD3);
             HUF_DECODE_SYMBOLX4_1(op4, &bitD4);
             HUF_DECODE_SYMBOLX4_2(op1, &bitD1);
             HUF_DECODE_SYMBOLX4_2(op2, &bitD2);
             HUF_DECODE_SYMBOLX4_2(op3, &bitD3);
             HUF_DECODE_SYMBOLX4_2(op4, &bitD4);
             HUF_DECODE_SYMBOLX4_0(op1, &bitD1);
             HUF_DECODE_SYMBOLX4_0(op2, &bitD2);
             HUF_DECODE_SYMBOLX4_0(op3, &bitD3);
             HUF_DECODE_SYMBOLX4_0(op4, &bitD4);
 
             endSignal = BIT_reloadDStream(&bitD1) | BIT_reloadDStream(&bitD2) | BIT_reloadDStream(&bitD3) | BIT_reloadDStream(&bitD4);
         }
 
         /* check corruption */
         if (op1 > opStart2) return ERROR(corruption_detected);
         if (op2 > opStart3) return ERROR(corruption_detected);
         if (op3 > opStart4) return ERROR(corruption_detected);
         /* note : op4 supposed already verified within main loop */
 
         /* finish bitStreams one by one */
         HUF_decodeStreamX4(op1, &bitD1, opStart2, dt, dtLog);
         HUF_decodeStreamX4(op2, &bitD2, opStart3, dt, dtLog);
         HUF_decodeStreamX4(op3, &bitD3, opStart4, dt, dtLog);
         HUF_decodeStreamX4(op4, &bitD4, oend,     dt, dtLog);
 
         /* check */
         endSignal = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
         if (!endSignal) return ERROR(corruption_detected);
 
         /* decoded size */
         return dstSize;
     }
 }
 
 
 static size_t HUF_decompress4X4 (void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize)
 {
     HUF_CREATE_STATIC_DTABLEX4(DTable, HUF_MAX_TABLELOG);
     const BYTE* ip = (const BYTE*) cSrc;
 
     size_t hSize = HUF_readDTableX4 (DTable, cSrc, cSrcSize);
     if (HUF_isError(hSize)) return hSize;
     if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
     ip += hSize;
     cSrcSize -= hSize;
 
     return HUF_decompress4X4_usingDTable (dst, dstSize, ip, cSrcSize, DTable);
 }
 
 
 /**********************************/
 /* quad-symbol decoding           */
 /**********************************/
 typedef struct { BYTE nbBits; BYTE nbBytes; } HUF_DDescX6;
 typedef union { BYTE byte[4]; U32 sequence; } HUF_DSeqX6;
 
 /* recursive, up to level 3; may benefit from