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contrib/compiler-rt/lib/builtins/floatunditf.c
- This file was added.
| //===-- lib/floatunditf.c - uint -> quad-precision conversion -----*- C -*-===// | |||||
| // | |||||
| // The LLVM Compiler Infrastructure | |||||
| // | |||||
| // This file is dual licensed under the MIT and the University of Illinois Open | |||||
| // Source Licenses. See LICENSE.TXT for details. | |||||
| // | |||||
| //===----------------------------------------------------------------------===// | |||||
| // | |||||
| // This file implements du_int to quad-precision conversion for the | |||||
| // compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even | |||||
| // mode. | |||||
| // | |||||
| //===----------------------------------------------------------------------===// | |||||
| #define QUAD_PRECISION | |||||
| #include "fp_lib.h" | |||||
| #if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT) | |||||
| COMPILER_RT_ABI fp_t __floatunditf(du_int int a) { | |||||
| const int aWidth = sizeof a * CHAR_BIT; | |||||
| // Handle zero as a special case to protect clz | |||||
| if (a == 0) return fromRep(0); | |||||
| // Exponent of (fp_t)a is the width of abs(a). | |||||
| const int exponent = (aWidth - 1) - __builtin_clz(a); | |||||
| rep_t result; | |||||
| // Shift a into the significand field and clear the implicit bit. | |||||
| const int shift = significandBits - exponent; | |||||
| result = (rep_t)a << shift ^ implicitBit; | |||||
| // Insert the exponent | |||||
| result += (rep_t)(exponent + exponentBias) << significandBits; | |||||
| return fromRep(result); | |||||
| } | |||||
| #endif | |||||