glibc/math/w_powf.c
2014-02-10 15:07:12 +01:00

75 lines
2.0 KiB
C

/* Copyright (C) 2011-2014 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 <math.h>
#include <math_private.h>
/* wrapper powf */
float
__powf (float x, float y)
{
float z = __ieee754_powf (x, y);
if (__glibc_unlikely (!__finitef (z)))
{
if (_LIB_VERSION != _IEEE_)
{
if (__isnanf (x))
{
if (y == 0.0f)
/* pow(NaN,0.0) */
return __kernel_standard_f (x, y, 142);
}
else if (__finitef (x) && __finitef (y))
{
if (__isnanf (z))
/* pow neg**non-int */
return __kernel_standard_f (x, y, 124);
else if (x == 0.0f && y < 0.0f)
{
if (signbit (x) && signbit (z))
/* pow(-0.0,negative) */
return __kernel_standard_f (x, y, 123);
else
/* pow(+0.0,negative) */
return __kernel_standard_f (x, y, 143);
}
else
/* pow overflow */
return __kernel_standard_f (x, y, 121);
}
}
}
else if (__builtin_expect (z == 0.0f, 0) && __finitef (x) && __finitef (y)
&& _LIB_VERSION != _IEEE_)
{
if (x == 0.0f)
{
if (y == 0.0f)
/* pow(0.0,0.0) */
return __kernel_standard_f (x, y, 120);
}
else
/* pow underflow */
return __kernel_standard_f (x, y, 122);
}
return z;
}
weak_alias (__powf, powf)