Differential D29529 Diff 86708 sys/amd64/include/asmacros.h

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sys/amd64/include/asmacros.h

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	* CNAME is used to manage the relationship between symbol names in C			* CNAME is used to manage the relationship between symbol names in C
	* and the equivalent assembly language names. CNAME is given a name as			* and the equivalent assembly language names. CNAME is given a name as
	* it would be used in a C program. It expands to the equivalent assembly			* it would be used in a C program. It expands to the equivalent assembly
	* language name.			* language name.
	*/			*/
	#define CNAME(csym) csym			#define CNAME(csym) csym

	#define ALIGN_DATA .p2align 3 /* 8 byte alignment, zero filled */			#define ALIGN_DATA .p2align 3 /* 8 byte alignment, zero filled */
	#ifdef GPROF
	#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */			#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
	#else
	#define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
	#endif
	#define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */			#define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */

	#define GEN_ENTRY(name) ALIGN_TEXT; .globl CNAME(name); \			#define GEN_ENTRY(name) ALIGN_TEXT; .globl CNAME(name); \
	.type CNAME(name),@function; CNAME(name):			.type CNAME(name),@function; CNAME(name):
	#define NON_GPROF_ENTRY(name) GEN_ENTRY(name)
	#define NON_GPROF_RET .byte 0xc3 /* opcode for `ret' */

	#define END(name) .size name, . - name

	#ifdef GPROF
	/*
	* __mcount is like [.]mcount except that doesn't require its caller to set
	* up a frame pointer. It must be called before pushing anything onto the
	* stack. gcc should eventually generate code to call __mcount in most
	* cases. This would make -pg in combination with -fomit-frame-pointer
	* useful. gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
	* allow profiling before setting up the frame pointer, but this is
	* inadequate for good handling of special cases, e.g., -fpic works best
	* with profiling after the prologue.
	*
	* [.]mexitcount is a new function to support non-statistical profiling if an
	* accurate clock is available. For C sources, calls to it are generated
	* by the FreeBSD extension `-mprofiler-epilogue' to gcc. It is best to
	* call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
	* but gcc currently generates calls to it at the start of the epilogue to
	* avoid problems with -fpic.
	*
	* [.]mcount and __mcount may clobber the call-used registers and %ef.
	* [.]mexitcount may clobber %ecx and %ef.
	*
	* Cross-jumping makes non-statistical profiling timing more complicated.
	* It is handled in many cases by calling [.]mexitcount before jumping. It
	* is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
	* It is handled for some fault-handling jumps by not sharing the exit
	* routine.
	*
	* ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
	* the main entry point. Note that alt entries are counted twice. They
	* have to be counted as ordinary entries for gprof to get the call times
	* right for the ordinary entries.
	*
	* High local labels are used in macros to avoid clashes with local labels
	* in functions.
	*
	* Ordinary `ret' is used instead of a macro `RET' because there are a lot
	* of `ret's. 0xc3 is the opcode for `ret' (`#define ret ... ret' can't
	* be used because this file is sometimes preprocessed in traditional mode).
	* `ret' clobbers eflags but this doesn't matter.
	*/
	#define ALTENTRY(name) GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
	#define CROSSJUMP(jtrue, label, jfalse) \
	jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
	#define CROSSJUMPTARGET(label) \
	ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
	#define ENTRY(name) GEN_ENTRY(name) ; 9: ; MCOUNT
	#define FAKE_MCOUNT(caller) pushq caller ; call __mcount ; popq %rcx
	#define MCOUNT call __mcount
	#define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT
	#ifdef GUPROF
	#define MEXITCOUNT call .mexitcount
	#define ret MEXITCOUNT ; NON_GPROF_RET
	#else
	#define MEXITCOUNT
	#endif

	#else /* !GPROF */
	/*
	* ALTENTRY() has to align because it is before a corresponding ENTRY().
	* ENTRY() has to align to because there may be no ALTENTRY() before it.
	* If there is a previous ALTENTRY() then the alignment code for ENTRY()
	* is empty.
	*/
	#define ALTENTRY(name) GEN_ENTRY(name)
	#define CROSSJUMP(jtrue, label, jfalse) jtrue label
	#define CROSSJUMPTARGET(label)
	#define ENTRY(name) GEN_ENTRY(name)			#define ENTRY(name) GEN_ENTRY(name)
	#define FAKE_MCOUNT(caller)			#define ALTENTRY(name) GEN_ENTRY(name)
	#define MCOUNT			#define END(name) .size name, . - name
	#define MCOUNT_LABEL(name)
	#define MEXITCOUNT
	#endif /* GPROF */

	/*			/*
	* Convenience for adding frame pointers to hand-coded ASM. Useful for			* Convenience for adding frame pointers to hand-coded ASM. Useful for
	* DTrace, HWPMC, and KDB.			* DTrace, HWPMC, and KDB.
	*/			*/
	#define PUSH_FRAME_POINTER \			#define PUSH_FRAME_POINTER \
	pushq %rbp ; \			pushq %rbp ; \
	movq %rsp, %rbp ;			movq %rsp, %rbp ;
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