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Diffstat (limited to 'lib/fp_lib.h')
| -rw-r--r-- | lib/fp_lib.h | 144 |
1 files changed, 0 insertions, 144 deletions
diff --git a/lib/fp_lib.h b/lib/fp_lib.h deleted file mode 100644 index 661119ae412a..000000000000 --- a/lib/fp_lib.h +++ /dev/null @@ -1,144 +0,0 @@ -//===-- lib/fp_lib.h - Floating-point utilities -------------------*- 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 is a configuration header for soft-float routines in compiler-rt. -// This file does not provide any part of the compiler-rt interface, but defines -// many useful constants and utility routines that are used in the -// implementation of the soft-float routines in compiler-rt. -// -// Assumes that float and double correspond to the IEEE-754 binary32 and -// binary64 types, respectively, and that integer endianness matches floating -// point endianness on the target platform. -// -//===----------------------------------------------------------------------===// - -#ifndef FP_LIB_HEADER -#define FP_LIB_HEADER - -#include <stdint.h> -#include <stdbool.h> -#include <limits.h> -#include "int_lib.h" - -#if defined SINGLE_PRECISION - -typedef uint32_t rep_t; -typedef int32_t srep_t; -typedef float fp_t; -#define REP_C UINT32_C -#define significandBits 23 - -static inline int rep_clz(rep_t a) { - return __builtin_clz(a); -} - -// 32x32 --> 64 bit multiply -static inline void wideMultiply(rep_t a, rep_t b, rep_t *hi, rep_t *lo) { - const uint64_t product = (uint64_t)a*b; - *hi = product >> 32; - *lo = product; -} - -#elif defined DOUBLE_PRECISION - -typedef uint64_t rep_t; -typedef int64_t srep_t; -typedef double fp_t; -#define REP_C UINT64_C -#define significandBits 52 - -static inline int rep_clz(rep_t a) { -#if defined __LP64__ - return __builtin_clzl(a); -#else - if (a & REP_C(0xffffffff00000000)) - return __builtin_clz(a >> 32); - else - return 32 + __builtin_clz(a & REP_C(0xffffffff)); -#endif -} - -#define loWord(a) (a & 0xffffffffU) -#define hiWord(a) (a >> 32) - -// 64x64 -> 128 wide multiply for platforms that don't have such an operation; -// many 64-bit platforms have this operation, but they tend to have hardware -// floating-point, so we don't bother with a special case for them here. -static inline void wideMultiply(rep_t a, rep_t b, rep_t *hi, rep_t *lo) { - // Each of the component 32x32 -> 64 products - const uint64_t plolo = loWord(a) * loWord(b); - const uint64_t plohi = loWord(a) * hiWord(b); - const uint64_t philo = hiWord(a) * loWord(b); - const uint64_t phihi = hiWord(a) * hiWord(b); - // Sum terms that contribute to lo in a way that allows us to get the carry - const uint64_t r0 = loWord(plolo); - const uint64_t r1 = hiWord(plolo) + loWord(plohi) + loWord(philo); - *lo = r0 + (r1 << 32); - // Sum terms contributing to hi with the carry from lo - *hi = hiWord(plohi) + hiWord(philo) + hiWord(r1) + phihi; -} - -#else -#error Either SINGLE_PRECISION or DOUBLE_PRECISION must be defined. -#endif - -#define typeWidth (sizeof(rep_t)*CHAR_BIT) -#define exponentBits (typeWidth - significandBits - 1) -#define maxExponent ((1 << exponentBits) - 1) -#define exponentBias (maxExponent >> 1) - -#define implicitBit (REP_C(1) << significandBits) -#define significandMask (implicitBit - 1U) -#define signBit (REP_C(1) << (significandBits + exponentBits)) -#define absMask (signBit - 1U) -#define exponentMask (absMask ^ significandMask) -#define oneRep ((rep_t)exponentBias << significandBits) -#define infRep exponentMask -#define quietBit (implicitBit >> 1) -#define qnanRep (exponentMask | quietBit) - -static inline rep_t toRep(fp_t x) { - const union { fp_t f; rep_t i; } rep = {.f = x}; - return rep.i; -} - -static inline fp_t fromRep(rep_t x) { - const union { fp_t f; rep_t i; } rep = {.i = x}; - return rep.f; -} - -static inline int normalize(rep_t *significand) { - const int shift = rep_clz(*significand) - rep_clz(implicitBit); - *significand <<= shift; - return 1 - shift; -} - -static inline void wideLeftShift(rep_t *hi, rep_t *lo, int count) { - *hi = *hi << count | *lo >> (typeWidth - count); - *lo = *lo << count; -} - -static inline void wideRightShiftWithSticky(rep_t *hi, rep_t *lo, unsigned int count) { - if (count < typeWidth) { - const bool sticky = *lo << (typeWidth - count); - *lo = *hi << (typeWidth - count) | *lo >> count | sticky; - *hi = *hi >> count; - } - else if (count < 2*typeWidth) { - const bool sticky = *hi << (2*typeWidth - count) | *lo; - *lo = *hi >> (count - typeWidth) | sticky; - *hi = 0; - } else { - const bool sticky = *hi | *lo; - *lo = sticky; - *hi = 0; - } -} - -#endif // FP_LIB_HEADER |