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Diffstat (limited to 'lib/floatundidf.c')
| -rw-r--r-- | lib/floatundidf.c | 107 |
1 files changed, 0 insertions, 107 deletions
diff --git a/lib/floatundidf.c b/lib/floatundidf.c deleted file mode 100644 index e52fa0a3359b..000000000000 --- a/lib/floatundidf.c +++ /dev/null @@ -1,107 +0,0 @@ -/* ===-- floatundidf.c - Implement __floatundidf ---------------------------=== - * - * 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 __floatundidf for the compiler_rt library. - * - * ===----------------------------------------------------------------------=== - */ - -/* Returns: convert a to a double, rounding toward even. */ - -/* Assumption: double is a IEEE 64 bit floating point type - * du_int is a 64 bit integral type - */ - -/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */ - -#include "int_lib.h" - -ARM_EABI_FNALIAS(ul2d, floatundidf) - -#ifndef __SOFT_FP__ -/* Support for systems that have hardware floating-point; we'll set the inexact flag - * as a side-effect of this computation. - */ - - -COMPILER_RT_ABI double -__floatundidf(du_int a) -{ - static const double twop52 = 0x1.0p52; - static const double twop84 = 0x1.0p84; - static const double twop84_plus_twop52 = 0x1.00000001p84; - - union { uint64_t x; double d; } high = { .d = twop84 }; - union { uint64_t x; double d; } low = { .d = twop52 }; - - high.x |= a >> 32; - low.x |= a & UINT64_C(0x00000000ffffffff); - - const double result = (high.d - twop84_plus_twop52) + low.d; - return result; -} - -#else -/* Support for systems that don't have hardware floating-point; there are no flags to - * set, and we don't want to code-gen to an unknown soft-float implementation. - */ - -COMPILER_RT_ABI double -__floatundidf(du_int a) -{ - if (a == 0) - return 0.0; - const unsigned N = sizeof(du_int) * CHAR_BIT; - int sd = N - __builtin_clzll(a); /* number of significant digits */ - int e = sd - 1; /* exponent */ - if (sd > DBL_MANT_DIG) - { - /* start: 0000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQxxxxxxxxxxxxxxxxxx - * finish: 000000000000000000000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQR - * 12345678901234567890123456 - * 1 = msb 1 bit - * P = bit DBL_MANT_DIG-1 bits to the right of 1 - * Q = bit DBL_MANT_DIG bits to the right of 1 - * R = "or" of all bits to the right of Q - */ - switch (sd) - { - case DBL_MANT_DIG + 1: - a <<= 1; - break; - case DBL_MANT_DIG + 2: - break; - default: - a = (a >> (sd - (DBL_MANT_DIG+2))) | - ((a & ((du_int)(-1) >> ((N + DBL_MANT_DIG+2) - sd))) != 0); - }; - /* finish: */ - a |= (a & 4) != 0; /* Or P into R */ - ++a; /* round - this step may add a significant bit */ - a >>= 2; /* dump Q and R */ - /* a is now rounded to DBL_MANT_DIG or DBL_MANT_DIG+1 bits */ - if (a & ((du_int)1 << DBL_MANT_DIG)) - { - a >>= 1; - ++e; - } - /* a is now rounded to DBL_MANT_DIG bits */ - } - else - { - a <<= (DBL_MANT_DIG - sd); - /* a is now rounded to DBL_MANT_DIG bits */ - } - double_bits fb; - fb.u.high = ((e + 1023) << 20) | /* exponent */ - ((su_int)(a >> 32) & 0x000FFFFF); /* mantissa-high */ - fb.u.low = (su_int)a; /* mantissa-low */ - return fb.f; -} -#endif |