diff options
Diffstat (limited to 'math/s_cacosh.c')
| -rw-r--r-- | math/s_cacosh.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/math/s_cacosh.c b/math/s_cacosh.c new file mode 100644 index 0000000000..ada7ca5af6 --- /dev/null +++ b/math/s_cacosh.c @@ -0,0 +1,95 @@ +/* Return arc hyperbole cosine for double value. + Copyright (C) 1997, 2006 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <complex.h> +#include <math.h> + + +__complex__ double +__cacosh (__complex__ double x) +{ + __complex__ double res; + int rcls = fpclassify (__real__ x); + int icls = fpclassify (__imag__ x); + + if (rcls <= FP_INFINITE || icls <= FP_INFINITE) + { + if (icls == FP_INFINITE) + { + __real__ res = HUGE_VAL; + + if (rcls == FP_NAN) + __imag__ res = __nan (""); + else + __imag__ res = __copysign ((rcls == FP_INFINITE + ? (__real__ x < 0.0 + ? M_PI - M_PI_4 : M_PI_4) + : M_PI_2), __imag__ x); + } + else if (rcls == FP_INFINITE) + { + __real__ res = HUGE_VAL; + + if (icls >= FP_ZERO) + __imag__ res = __copysign (signbit (__real__ x) ? M_PI : 0.0, + __imag__ x); + else + __imag__ res = __nan (""); + } + else + { + __real__ res = __nan (""); + __imag__ res = __nan (""); + } + } + else if (rcls == FP_ZERO && icls == FP_ZERO) + { + __real__ res = 0.0; + __imag__ res = __copysign (M_PI_2, __imag__ x); + } + else + { + __complex__ double y; + + __real__ y = (__real__ x - __imag__ x) * (__real__ x + __imag__ x) - 1.0; + __imag__ y = 2.0 * __real__ x * __imag__ x; + + y = __csqrt (y); + + if (__real__ x < 0.0) + y = -y; + + __real__ y += __real__ x; + __imag__ y += __imag__ x; + + res = __clog (y); + + /* We have to use the positive branch. */ + if (__real__ res < 0.0) + res = -res; + } + + return res; +} +weak_alias (__cacosh, cacosh) +#ifdef NO_LONG_DOUBLE +strong_alias (__cacosh, __cacoshl) +weak_alias (__cacosh, cacoshl) +#endif |