glibc/math/w_pow_template.c

53 lines
1.7 KiB
C

/* Wrapper to set errno for pow.
Copyright (C) 2017-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
/* Only build wrappers from the templates for the types that define the macro
below. This macro is set in math-type-macros-<type>.h in sysdeps/generic
for each floating-point type. */
#if __USE_WRAPPER_TEMPLATE
# include <errno.h>
# include <fenv.h>
# include <math.h>
# include <math_private.h>
FLOAT
M_DECL_FUNC (__pow) (FLOAT x, FLOAT y)
{
FLOAT z = M_SUF (__ieee754_pow) (x, y);
if (__glibc_unlikely (!isfinite (z)))
{
if (isfinite (x) && isfinite (y))
{
if (isnan (z))
/* Domain error: pow(x<0,y=non-integer). */
__set_errno (EDOM);
else
/* Pole error: pow(x=0,y<0). Or overflow. */
__set_errno (ERANGE);
}
}
else if (__glibc_unlikely (z == 0) && isfinite (x) && x != 0 && isfinite (y))
/* Underflow. */
__set_errno (ERANGE);
return z;
}
declare_mgen_alias (__pow, pow)
#endif /* __USE_WRAPPER_TEMPLATE. */