/* Return arc hyperbolic cosine for a complex type.

   Copyright (C) 1997-2018 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>

CFLOAT

M_DECL_FUNC (__cacosh) (CFLOAT x)

{

  CFLOAT res;

  int rcls = fpclassify (__real__ x);

  int icls = fpclassify (__imag__ x);

  if (rcls <= FP_INFINITE || icls <= FP_INFINITE)

    {

      if (icls == FP_INFINITE)

	{

	  __real__ res = M_HUGE_VAL;

	  if (rcls == FP_NAN)

	    __imag__ res = M_NAN;

	  else

	    __imag__ res = M_COPYSIGN ((rcls == FP_INFINITE

					? (__real__ x < 0

					   ? M_MLIT (M_PI) - M_MLIT (M_PI_4)

					   : M_MLIT (M_PI_4))

					: M_MLIT (M_PI_2)), __imag__ x);

	}

      else if (rcls == FP_INFINITE)

	{

	  __real__ res = M_HUGE_VAL;

	  if (icls >= FP_ZERO)

	    __imag__ res = M_COPYSIGN (signbit (__real__ x)

				       ? M_MLIT (M_PI) : 0, __imag__ x);

	  else

	    __imag__ res = M_NAN;

	}

      else

	{

	  __real__ res = M_NAN;

	  if (rcls == FP_ZERO)

	    __imag__ res = M_MLIT (M_PI_2);

	  else

	    __imag__ res = M_NAN;

	}

    }

  else if (rcls == FP_ZERO && icls == FP_ZERO)

    {

      __real__ res = 0;

      __imag__ res = M_COPYSIGN (M_MLIT (M_PI_2), __imag__ x);

    }

  else

    {

      CFLOAT y;

      __real__ y = -__imag__ x;

      __imag__ y = __real__ x;

      y = M_SUF (__kernel_casinh) (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;

}

declare_mgen_alias (__cacosh, cacosh)