1/* Return cosine of a complex type.
2 Copyright (C) 1997-2020 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 <https://www.gnu.org/licenses/>. */
19
20#include <complex.h>
21#include <math.h>
22
23CFLOAT
24M_DECL_FUNC (__cacos) (CFLOAT x)
25{
26 CFLOAT y;
27 CFLOAT 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 = M_SUF (__casin) (x);
35
36 __real__ res = (FLOAT) M_MLIT (M_PI_2) - __real__ y;
37 if (__real__ res == 0)
38 __real__ res = 0;
39 __imag__ res = -__imag__ y;
40 }
41 else
42 {
43 __real__ y = -__imag__ x;
44 __imag__ y = __real__ x;
45
46 y = M_SUF (__kernel_casinh) (y, 1);
47
48 __real__ res = __imag__ y;
49 __imag__ res = __real__ y;
50 }
51
52 return res;
53}
54
55declare_mgen_alias (__cacos, cacos);
56