glibc/math/w_tgamma_template.c

56 lines
1.8 KiB
C

/* Wrapper to set errno for tgamma.
Copyright (C) 2017 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>
#define M_CALL_FUNC_X(x) x ## _r
#define M_CALL_FUNC(x) M_CALL_FUNC_X (x)
FLOAT
M_DECL_FUNC (__tgamma) (FLOAT x)
{
int local_signgam;
FLOAT y = M_CALL_FUNC (M_SUF (__ieee754_gamma)) (x, &local_signgam);
if (__glibc_unlikely (!isfinite (y) || y == 0)
&& (isfinite (x) || (isinf (x) && x < 0)))
{
if (x == 0)
/* Pole error: tgamma(x=0). */
__set_errno (ERANGE);
else if (M_SUF (__floor) (x) == x && x < 0)
/* Domain error: tgamma(integer x<0). */
__set_errno (EDOM);
else
/* Overflow or underflow. */
__set_errno (ERANGE);
}
return local_signgam < 0 ? -y : y;
}
declare_mgen_alias (__tgamma, tgamma)
#endif /* __USE_WRAPPER_TEMPLATE. */