google3/third_party/grte/v4_src/glibc-2.19/math/s_cacoshl.c

/* Return arc hyperbole cosine for long double value.
   Copyright (C) 1997-2014 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>
#include <math_private.h>


__complex__ long double
__cacoshl (__complex__ long double x)
{
  __complex__ long 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_VALL;

	  if (rcls == FP_NAN)
	    __imag__ res = __nanl ("");
	  else
	    __imag__ res = __copysignl ((rcls == FP_INFINITE
					 ? (__real__ x < 0.0
					    ? M_PIl - M_PI_4l : M_PI_4l)
					 : M_PI_2l), __imag__ x);
	}
      else if (rcls == FP_INFINITE)
	{
	  __real__ res = HUGE_VALL;

	  if (icls >= FP_ZERO)
	    __imag__ res = __copysignl (signbit (__real__ x) ? M_PIl : 0.0,
					__imag__ x);
	  else
	    __imag__ res = __nanl ("");
	}
      else
	{
	  __real__ res = __nanl ("");
	  __imag__ res = __nanl ("");
	}
    }
  else if (rcls == FP_ZERO && icls == FP_ZERO)
    {
      __real__ res = 0.0;
      __imag__ res = __copysignl (M_PI_2l, __imag__ x);
    }
  else
    {
      __complex__ long double y;

      __real__ y = -__imag__ x;
      __imag__ y = __real__ x;

      y = __kernel_casinhl (y, 1);

      if (signbit (__imag__ x))
	{
	  __real__ res = __real__ y;
	  __imag__ res = -__imag__ y;
	}
      else
	{
	  __real__ res = -__real__ y;
	  __imag__ res = __imag__ y;
	}
    }

  return res;
}
weak_alias (__cacoshl, cacoshl)