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 | |
23 | /* wrapper pow */ |
24 | double |
25 | __pow (double x, double y) |
26 | { |
27 | double z = __ieee754_pow (x, y); |
28 | if (__glibc_unlikely (!isfinite (z))) |
29 | { |
30 | if (_LIB_VERSION != _IEEE_) |
31 | { |
32 | if (isnan (x)) |
33 | { |
34 | if (y == 0.0) |
35 | /* pow(NaN,0.0) */ |
36 | return __kernel_standard (x, y, 42); |
37 | } |
38 | else if (isfinite (x) && isfinite (y)) |
39 | { |
40 | if (isnan (z)) |
41 | /* pow neg**non-int */ |
42 | return __kernel_standard (x, y, 24); |
43 | else if (x == 0.0 && y < 0.0) |
44 | { |
45 | if (signbit (x) && signbit (z)) |
46 | /* pow(-0.0,negative) */ |
47 | return __kernel_standard (x, y, 23); |
48 | else |
49 | /* pow(+0.0,negative) */ |
50 | return __kernel_standard (x, y, 43); |
51 | } |
52 | else |
53 | /* pow overflow */ |
54 | return __kernel_standard (x, y, 21); |
55 | } |
56 | } |
57 | } |
58 | else if (__builtin_expect (z == 0.0, 0) && isfinite (x) && isfinite (y) |
59 | && _LIB_VERSION != _IEEE_) |
60 | { |
61 | if (x == 0.0) |
62 | { |
63 | if (y == 0.0) |
64 | /* pow(0.0,0.0) */ |
65 | return __kernel_standard (x, y, 20); |
66 | } |
67 | else |
68 | /* pow underflow */ |
69 | return __kernel_standard (x, y, 22); |
70 | } |
71 | |
72 | return z; |
73 | } |
74 | weak_alias (__pow, pow) |
75 | #ifdef NO_LONG_DOUBLE |
76 | strong_alias (__pow, __powl) |
77 | weak_alias (__pow, powl) |
78 | #endif |
79 | |