glibc/sysdeps/ieee754/dbl-64/w_exp.c
Ulrich Drepper bcf01e6d80 Optimize exp
Add __exp*_finite optimizations and rewrite some wrappers.
2011-10-15 20:22:59 -04:00

51 lines
1.6 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 <math.h>
#include <math_private.h>
static const double
o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */
u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */
/* wrapper exp */
double
__exp (double x)
{
if (__builtin_expect (x > o_threshold, 0))
{
if (_LIB_VERSION != _IEEE_)
return __kernel_standard_f (x, x, 6);
}
else if (__builtin_expect (x < u_threshold, 0))
{
if (_LIB_VERSION != _IEEE_)
return __kernel_standard_f (x, x, 7);
}
return __ieee754_exp (x);
}
hidden_def (__exp)
weak_alias (__exp, exp)
#ifdef NO_LONG_DOUBLE
strong_alias (__exp, __expl)
weak_alias (__exp, expl)
#endif