1/* Wrapper to set errno for pow.
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
29FLOAT
30M_DECL_FUNC (__pow) (FLOAT x, FLOAT y)
31{
32 FLOAT z = M_SUF (__ieee754_pow) (x, y);
33 if (__glibc_unlikely (!isfinite (z)))
34 {
35 if (isfinite (x) && isfinite (y))
36 {
37 if (isnan (z))
38 /* Domain error: pow(x<0,y=non-integer). */
39 __set_errno (EDOM);
40 else
41 /* Pole error: pow(x=0,y<0). Or overflow. */
42 __set_errno (ERANGE);
43 }
44 }
45 else if (__glibc_unlikely (z == 0) && isfinite (x) && x != 0 && isfinite (y))
46 /* Underflow. */
47 __set_errno (ERANGE);
48 return z;
49}
50declare_mgen_alias (__pow, pow)
51
52#endif /* __USE_WRAPPER_TEMPLATE. */
53

source code of glibc/math/w_pow_template.c