/* Return value of complex exponential function for a float 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 <fenv.h>

#include <math.h>

#include <math_private.h>

#include <math-underflow.h>

#include <float.h>

CFLOAT

M_DECL_FUNC (__cexp) (CFLOAT x)

{

  CFLOAT retval;

  int rcls = fpclassify (__real__ x);

  int icls = fpclassify (__imag__ x);

  if (__glibc_likely (rcls >= FP_ZERO))

    {

      /* Real part is finite.  */

      if (__glibc_likely (icls >= FP_ZERO))

	{

	  /* Imaginary part is finite.  */

	  const int t = (int) ((M_MAX_EXP - 1) * M_MLIT (M_LN2));

	  FLOAT sinix, cosix;

	  if (__glibc_likely (M_FABS (__imag__ x) > M_MIN))

	    {

	      M_SINCOS (__imag__ x, &sinix, &cosix);

	    }

	  else

	    {

	      sinix = __imag__ x;

	      cosix = 1;

	    }

	  if (__real__ x > t)

	    {

	      FLOAT exp_t = M_EXP (t);

	      __real__ x -= t;

	      sinix *= exp_t;

	      cosix *= exp_t;

	      if (__real__ x > t)

		{

		  __real__ x -= t;

		  sinix *= exp_t;

		  cosix *= exp_t;

		}

	    }

	  if (__real__ x > t)

	    {

	      /* Overflow (original real part of x > 3t).  */

	      __real__ retval = M_MAX * cosix;

	      __imag__ retval = M_MAX * sinix;

	    }

	  else

	    {

	      FLOAT exp_val = M_EXP (__real__ x);

	      __real__ retval = exp_val * cosix;

	      __imag__ retval = exp_val * sinix;

	    }

	  math_check_force_underflow_complex (retval);

	}

      else

	{

	  /* If the imaginary part is +-inf or NaN and the real part

	     is not +-inf the result is NaN + iNaN.  */

	  __real__ retval = M_NAN;

	  __imag__ retval = M_NAN;

	  feraiseexcept (FE_INVALID);

	}

    }

  else if (__glibc_likely (rcls == FP_INFINITE))

    {

      /* Real part is infinite.  */

      if (__glibc_likely (icls >= FP_ZERO))

	{

	  /* Imaginary part is finite.  */

	  FLOAT value = signbit (__real__ x) ? 0 : M_HUGE_VAL;

	  if (icls == FP_ZERO)

	    {

	      /* Imaginary part is 0.0.  */

	      __real__ retval = value;

	      __imag__ retval = __imag__ x;

	    }

	  else

	    {

	      FLOAT sinix, cosix;

	      if (__glibc_likely (M_FABS (__imag__ x) > M_MIN))

		{

		  M_SINCOS (__imag__ x, &sinix, &cosix);

		}

	      else

		{

		  sinix = __imag__ x;

		  cosix = 1;

		}

	      __real__ retval = M_COPYSIGN (value, cosix);

	      __imag__ retval = M_COPYSIGN (value, sinix);

	    }

	}

      else if (signbit (__real__ x) == 0)

	{

	  __real__ retval = M_HUGE_VAL;

	  __imag__ retval = __imag__ x - __imag__ x;

	}

      else

	{

	  __real__ retval = 0;

	  __imag__ retval = M_COPYSIGN (0, __imag__ x);

	}

    }

  else

    {

      /* If the real part is NaN the result is NaN + iNaN unless the

	 imaginary part is zero.  */

      __real__ retval = M_NAN;

      if (icls == FP_ZERO)

	__imag__ retval = __imag__ x;

      else

	{

	  __imag__ retval = M_NAN;

	  if (rcls != FP_NAN || icls != FP_NAN)

	    feraiseexcept (FE_INVALID);

	}

    }

  return retval;

}

declare_mgen_alias (__cexp, cexp)