glibc/math/s_cacos.c

57 lines
1.6 KiB
C

/* Return cosine of complex double value.
Copyright (C) 1997-2013 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, see
<http://www.gnu.org/licenses/>. */
#include <complex.h>
#include <math.h>
__complex__ double
__cacos (__complex__ double x)
{
__complex__ double y;
__complex__ double res;
int rcls = fpclassify (__real__ x);
int icls = fpclassify (__imag__ x);
if (rcls <= FP_INFINITE || icls <= FP_INFINITE
|| (rcls == FP_ZERO && icls == FP_ZERO))
{
y = __casin (x);
__real__ res = (double) M_PI_2 - __real__ y;
__imag__ res = -__imag__ y;
}
else
{
__real__ y = -__imag__ x;
__imag__ y = __real__ x;
y = __kernel_casinh (y, 1);
__real__ res = __imag__ y;
__imag__ res = __real__ y;
}
return res;
}
weak_alias (__cacos, cacos)
#ifdef NO_LONG_DOUBLE
strong_alias (__cacos, __cacosl)
weak_alias (__cacos, cacosl)
#endif