diff options
Diffstat (limited to 'REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c')
| -rw-r--r-- | REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c b/REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c new file mode 100644 index 0000000000..5e8bc64711 --- /dev/null +++ b/REORG.TODO/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c @@ -0,0 +1,69 @@ +/* Copyright (C) 2011-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@gmail.com>, 2011. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <inttypes.h> +#include <math.h> +#include <math_private.h> + +/* + * for non-zero, finite x + * x = frexp(arg,&exp); + * return a double fp quantity x such that 0.5 <= |x| <1.0 + * and the corresponding binary exponent "exp". That is + * arg = x*2^exp. + * If arg is inf, 0.0, or NaN, then frexp(arg,&exp) returns arg + * with *exp=0. + */ + + +double +__frexp (double x, int *eptr) +{ + int64_t ix; + EXTRACT_WORDS64 (ix, x); + int32_t ex = 0x7ff & (ix >> 52); + int e = 0; + + if (__glibc_likely (ex != 0x7ff && x != 0.0)) + { + /* Not zero and finite. */ + e = ex - 1022; + if (__glibc_unlikely (ex == 0)) + { + /* Subnormal. */ + x *= 0x1p54; + EXTRACT_WORDS64 (ix, x); + ex = 0x7ff & (ix >> 52); + e = ex - 1022 - 54; + } + + ix = (ix & INT64_C (0x800fffffffffffff)) | INT64_C (0x3fe0000000000000); + INSERT_WORDS64 (x, ix); + } + else + /* Quiet signaling NaNs. */ + x += x; + + *eptr = e; + return x; +} +weak_alias (__frexp, frexp) +#ifdef NO_LONG_DOUBLE +strong_alias (__frexp, __frexpl) +weak_alias (__frexp, frexpl) +#endif |