glibc/math/w_log.c
Ulrich Drepper 0ac5ae2335 Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option
and lots of the wrapper functions have been optimized.
2011-10-12 11:27:51 -04:00

50 lines
1.4 KiB
C

/* Copyright (C) 2011 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <fenv.h>
#include <math.h>
#include <math_private.h>
/* wrapper log(x) */
double
__log (double x)
{
if (__builtin_expect (x <= 0.0, 0) && _LIB_VERSION != _IEEE_)
{
if (x == 0.0)
{
feraiseexcept (FE_DIVBYZERO);
return __kernel_standard (x, x, 16); /* log(0) */
}
else
{
feraiseexcept (FE_INVALID);
return __kernel_standard (x, x, 17); /* log(x<0) */
}
}
return __ieee754_log (x);
}
weak_alias (__log, log)
#ifdef NO_LONG_DOUBLE
strong_alias (__log, __logl)
weak_alias (__log, logl)
#endif