1 | /* Return cosine of complex double value. |
2 | Copyright (C) 1997-2016 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <complex.h> |
21 | #include <math.h> |
22 | |
23 | __complex__ double |
24 | __cacos (__complex__ double x) |
25 | { |
26 | __complex__ double y; |
27 | __complex__ double res; |
28 | int rcls = fpclassify (__real__ x); |
29 | int icls = fpclassify (__imag__ x); |
30 | |
31 | if (rcls <= FP_INFINITE || icls <= FP_INFINITE |
32 | || (rcls == FP_ZERO && icls == FP_ZERO)) |
33 | { |
34 | y = __casin (x); |
35 | |
36 | __real__ res = (double) M_PI_2 - __real__ y; |
37 | if (__real__ res == 0.0) |
38 | __real__ res = 0.0; |
39 | __imag__ res = -__imag__ y; |
40 | } |
41 | else |
42 | { |
43 | __real__ y = -__imag__ x; |
44 | __imag__ y = __real__ x; |
45 | |
46 | y = __kernel_casinh (y, 1); |
47 | |
48 | __real__ res = __imag__ y; |
49 | __imag__ res = __real__ y; |
50 | } |
51 | |
52 | return res; |
53 | } |
54 | weak_alias (__cacos, cacos) |
55 | #ifdef NO_LONG_DOUBLE |
56 | strong_alias (__cacos, __cacosl) |
57 | weak_alias (__cacos, cacosl) |
58 | #endif |
59 | |