1/* Wrapper to set errno for tgamma.
2 Copyright (C) 2017-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19/* Only build wrappers from the templates for the types that define the macro
20 below. This macro is set in math-type-macros-<type>.h in sysdeps/generic
21 for each floating-point type. */
22#if __USE_WRAPPER_TEMPLATE
23
24# include <errno.h>
25# include <fenv.h>
26# include <math.h>
27# include <math_private.h>
28
29#define M_CALL_FUNC_X(x) x ## _r
30#define M_CALL_FUNC(x) M_CALL_FUNC_X (x)
31
32FLOAT
33M_DECL_FUNC (__tgamma) (FLOAT x)
34{
35 int local_signgam;
36 FLOAT y = M_CALL_FUNC (M_SUF (__ieee754_gamma)) (x, &local_signgam);
37
38 if (__glibc_unlikely (!isfinite (y) || y == 0)
39 && (isfinite (x) || (isinf (x) && x < 0)))
40 {
41 if (x == 0)
42 /* Pole error: tgamma(x=0). */
43 __set_errno (ERANGE);
44 else if (M_SUF (floor) (x) == x && x < 0)
45 /* Domain error: tgamma(integer x<0). */
46 __set_errno (EDOM);
47 else
48 /* Overflow or underflow. */
49 __set_errno (ERANGE);
50 }
51 return local_signgam < 0 ? -y : y;
52}
53declare_mgen_alias (__tgamma, tgamma)
54
55#endif /* __USE_WRAPPER_TEMPLATE. */
56

source code of glibc/math/w_tgamma_template.c