mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-08 22:30:07 +00:00
49 lines
1.4 KiB
C
49 lines
1.4 KiB
C
/* Copyright (C) 2011-2016 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 <fenv.h>
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
|
|
|
|
/* wrapper log2(x) */
|
|
double
|
|
__log2 (double x)
|
|
{
|
|
if (__builtin_expect (islessequal (x, 0.0), 0) && _LIB_VERSION != _IEEE_)
|
|
{
|
|
if (x == 0.0)
|
|
{
|
|
feraiseexcept (FE_DIVBYZERO);
|
|
return __kernel_standard (x, x, 48); /* log2(0) */
|
|
}
|
|
else
|
|
{
|
|
feraiseexcept (FE_INVALID);
|
|
return __kernel_standard (x, x, 49); /* log2(x<0) */
|
|
}
|
|
}
|
|
|
|
return __ieee754_log2 (x);
|
|
}
|
|
weak_alias (__log2, log2)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__log2, __log2l)
|
|
weak_alias (__log2, log2l)
|
|
#endif
|