1 /* Return arc hyperbole cosine for double value.
2 Copyright (C) 1997, 2006, 2011 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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.
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.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 #include <math_private.h>
27 __cacosh (__complex__ double x)
29 __complex__ double res;
30 int rcls = fpclassify (__real__ x);
31 int icls = fpclassify (__imag__ x);
33 if (rcls <= FP_INFINITE || icls <= FP_INFINITE)
35 if (icls == FP_INFINITE)
37 __real__ res = HUGE_VAL;
40 __imag__ res = __nan ("");
42 __imag__ res = __copysign ((rcls == FP_INFINITE
44 ? M_PI - M_PI_4 : M_PI_4)
45 : M_PI_2), __imag__ x);
47 else if (rcls == FP_INFINITE)
49 __real__ res = HUGE_VAL;
52 __imag__ res = __copysign (signbit (__real__ x) ? M_PI : 0.0,
55 __imag__ res = __nan ("");
59 __real__ res = __nan ("");
60 __imag__ res = __nan ("");
63 else if (rcls == FP_ZERO && icls == FP_ZERO)
66 __imag__ res = __copysign (M_PI_2, __imag__ x);
72 __real__ y = (__real__ x - __imag__ x) * (__real__ x + __imag__ x) - 1.0;
73 __imag__ y = 2.0 * __real__ x * __imag__ x;
77 if (signbit (__real__ x))
80 __real__ y += __real__ x;
81 __imag__ y += __imag__ x;
88 weak_alias (__cacosh, cacosh)
90 strong_alias (__cacosh, __cacoshl)
91 weak_alias (__cacosh, cacoshl)