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author | Anton Samokhvalov <pg83@yandex.ru> | 2022-02-10 16:45:17 +0300 |
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committer | Daniil Cherednik <dcherednik@yandex-team.ru> | 2022-02-10 16:45:17 +0300 |
commit | d3a398281c6fd1d3672036cb2d63f842d2cb28c5 (patch) | |
tree | dd4bd3ca0f36b817e96812825ffaf10d645803f2 /contrib/libs/cxxsupp/builtins/floatundisf.c | |
parent | 72cb13b4aff9bc9cf22e49251bc8fd143f82538f (diff) | |
download | ydb-d3a398281c6fd1d3672036cb2d63f842d2cb28c5.tar.gz |
Restoring authorship annotation for Anton Samokhvalov <pg83@yandex.ru>. Commit 2 of 2.
Diffstat (limited to 'contrib/libs/cxxsupp/builtins/floatundisf.c')
-rw-r--r-- | contrib/libs/cxxsupp/builtins/floatundisf.c | 154 |
1 files changed, 77 insertions, 77 deletions
diff --git a/contrib/libs/cxxsupp/builtins/floatundisf.c b/contrib/libs/cxxsupp/builtins/floatundisf.c index fbf2a9ec56..713a44abc8 100644 --- a/contrib/libs/cxxsupp/builtins/floatundisf.c +++ b/contrib/libs/cxxsupp/builtins/floatundisf.c @@ -1,77 +1,77 @@ -/*===-- floatundisf.c - Implement __floatundisf ---------------------------=== - * - * 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 __floatundisf for the compiler_rt library. - * - *===----------------------------------------------------------------------=== - */ - -/* Returns: convert a to a float, rounding toward even. */ - -/* Assumption: float is a IEEE 32 bit floating point type - * du_int is a 64 bit integral type - */ - -/* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */ - -#include "int_lib.h" - -ARM_EABI_FNALIAS(ul2f, floatundisf) - -COMPILER_RT_ABI float -__floatundisf(du_int a) -{ - if (a == 0) - return 0.0F; - const unsigned N = sizeof(du_int) * CHAR_BIT; - int sd = N - __builtin_clzll(a); /* number of significant digits */ - int e = sd - 1; /* 8 exponent */ - if (sd > FLT_MANT_DIG) - { - /* start: 0000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQxxxxxxxxxxxxxxxxxx - * finish: 000000000000000000000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQR - * 12345678901234567890123456 - * 1 = msb 1 bit - * P = bit FLT_MANT_DIG-1 bits to the right of 1 - * Q = bit FLT_MANT_DIG bits to the right of 1 - * R = "or" of all bits to the right of Q - */ - switch (sd) - { - case FLT_MANT_DIG + 1: - a <<= 1; - break; - case FLT_MANT_DIG + 2: - break; - default: - a = (a >> (sd - (FLT_MANT_DIG+2))) | - ((a & ((du_int)(-1) >> ((N + FLT_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 FLT_MANT_DIG or FLT_MANT_DIG+1 bits */ - if (a & ((du_int)1 << FLT_MANT_DIG)) - { - a >>= 1; - ++e; - } - /* a is now rounded to FLT_MANT_DIG bits */ - } - else - { - a <<= (FLT_MANT_DIG - sd); - /* a is now rounded to FLT_MANT_DIG bits */ - } - float_bits fb; - fb.u = ((e + 127) << 23) | /* exponent */ - ((su_int)a & 0x007FFFFF); /* mantissa */ - return fb.f; -} +/*===-- floatundisf.c - Implement __floatundisf ---------------------------=== + * + * 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 __floatundisf for the compiler_rt library. + * + *===----------------------------------------------------------------------=== + */ + +/* Returns: convert a to a float, rounding toward even. */ + +/* Assumption: float is a IEEE 32 bit floating point type + * du_int is a 64 bit integral type + */ + +/* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */ + +#include "int_lib.h" + +ARM_EABI_FNALIAS(ul2f, floatundisf) + +COMPILER_RT_ABI float +__floatundisf(du_int a) +{ + if (a == 0) + return 0.0F; + const unsigned N = sizeof(du_int) * CHAR_BIT; + int sd = N - __builtin_clzll(a); /* number of significant digits */ + int e = sd - 1; /* 8 exponent */ + if (sd > FLT_MANT_DIG) + { + /* start: 0000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQxxxxxxxxxxxxxxxxxx + * finish: 000000000000000000000000000000000000001xxxxxxxxxxxxxxxxxxxxxxPQR + * 12345678901234567890123456 + * 1 = msb 1 bit + * P = bit FLT_MANT_DIG-1 bits to the right of 1 + * Q = bit FLT_MANT_DIG bits to the right of 1 + * R = "or" of all bits to the right of Q + */ + switch (sd) + { + case FLT_MANT_DIG + 1: + a <<= 1; + break; + case FLT_MANT_DIG + 2: + break; + default: + a = (a >> (sd - (FLT_MANT_DIG+2))) | + ((a & ((du_int)(-1) >> ((N + FLT_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 FLT_MANT_DIG or FLT_MANT_DIG+1 bits */ + if (a & ((du_int)1 << FLT_MANT_DIG)) + { + a >>= 1; + ++e; + } + /* a is now rounded to FLT_MANT_DIG bits */ + } + else + { + a <<= (FLT_MANT_DIG - sd); + /* a is now rounded to FLT_MANT_DIG bits */ + } + float_bits fb; + fb.u = ((e + 127) << 23) | /* exponent */ + ((su_int)a & 0x007FFFFF); /* mantissa */ + return fb.f; +} |