1 /* Copyright (C) 2011-2016 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
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 <http://www.gnu.org/licenses/>. */
18
19 #include <math.h>
20 #include "math_private.h"
21
22 /* wrapper powf */
23 float
powf(float x,float y)24 powf (float x, float y)
25 {
26 #if defined(__UCLIBC_HAS_FENV__)
27 float z = (float) __ieee754_pow ((double) x, (double) y);
28 if (__builtin_expect (!isfinite (z), 0))
29 {
30 if (_LIB_VERSION != _IEEE_)
31 {
32 if (isnan (x))
33 {
34 if (y == 0.0f)
35 /* pow(NaN,0.0) */
36 return __kernel_standard_f (x, y, 142);
37 }
38 else if (isfinite (x) && isfinite (y))
39 {
40 if (isnan (z))
41 /* pow neg**non-int */
42 return __kernel_standard_f (x, y, 124);
43 else if (x == 0.0f && y < 0.0f)
44 {
45 if (signbit (x) && signbit (z))
46 /* pow(-0.0,negative) */
47 return __kernel_standard_f (x, y, 123);
48 else
49 /* pow(+0.0,negative) */
50 return __kernel_standard_f (x, y, 143);
51 }
52 else
53 /* pow overflow */
54 return __kernel_standard_f (x, y, 121);
55 }
56 }
57 }
58 else if (__builtin_expect (z == 0.0f, 0) && isfinite (x) && isfinite (y)
59 && _LIB_VERSION != _IEEE_)
60 {
61 if (x == 0.0f)
62 {
63 if (y == 0.0f)
64 /* pow(0.0,0.0) */
65 return __kernel_standard_f (x, y, 120);
66 }
67 else
68 /* pow underflow */
69 return __kernel_standard_f (x, y, 122);
70 }
71
72 return z;
73 #else
74 return (float) __ieee754_pow ((double) x, (double) y);
75 #endif /* __UCLIBC_HAS_FENV__ */
76 }
77