1/* Copyright (C) 2011-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <math.h>
19#include <math_private.h>
20#include <math-svid-compat.h>
21#include <libm-alias-ldouble.h>
22
23
24#if LIBM_SVID_COMPAT
25/* wrapper powl */
26long double
27__powl (long double x, long double y)
28{
29 long double z = __ieee754_powl (x, y);
30 if (__glibc_unlikely (!isfinite (z)))
31 {
32 if (_LIB_VERSION != _IEEE_)
33 {
34 if (isfinite (x) && isfinite (y))
35 {
36 if (isnan (z))
37 /* pow neg**non-int */
38 return __kernel_standard_l (x, y, 224);
39 else if (x == 0.0L && y < 0.0L)
40 {
41 if (signbit (x) && signbit (z))
42 /* pow(-0.0,negative) */
43 return __kernel_standard_l (x, y, 223);
44 else
45 /* pow(+0.0,negative) */
46 return __kernel_standard_l (x, y, 243);
47 }
48 else
49 /* pow overflow */
50 return __kernel_standard_l (x, y, 221);
51 }
52 }
53 }
54 else if (__builtin_expect (z == 0.0L, 0)
55 && isfinite (x) && x != 0 && isfinite (y)
56 && _LIB_VERSION != _IEEE_)
57 /* pow underflow */
58 return __kernel_standard_l (x, y, 222);
59
60 return z;
61}
62libm_alias_ldouble (__pow, pow)
63#endif
64

source code of glibc/math/w_powl_compat.c