sysdeps/libm-ieee754/s_cexpl.c

   1 /* Return value of complex exponential function for long double complex value.
   2    Copyright (C) 1997 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <complex.h>
  22 #include <math.h>
  23
  24 #include "math_private.h"
  25
  26
  27 __complex__ long double
  28 __cexpl (__complex__ long double x)
  29 {
  30   __complex__ long double retval;
  31   int rcls = fpclassify (__real__ x);
  32   int icls = fpclassify (__imag__ x);
  33
  34   if (rcls >= FP_ZERO)
  35     {
  36       /* Real part is finite.  */
  37       if (icls >= FP_ZERO)
  38         {
  39           /* Imaginary part is finite.  */
  40           long double exp_val = __ieee754_expl (__real__ x);
  41           long double sinix, cosix;
  42
  43           __sincosl (__imag__ x, &sinix, &cosix);
  44
  45           if (isfinite (exp_val))
  46             {
  47               __real__ retval = exp_val * cosix;
  48               __imag__ retval = exp_val * sinix;
  49             }
  50           else
  51             {
  52               __real__ retval = __copysignl (exp_val, cosix);
  53               __imag__ retval = __copysignl (exp_val, sinix);
  54             }
  55         }
  56       else
  57         {
  58           /* If the imaginary part is +-inf or NaN and the real part
  59              is not +-inf the result is NaN + iNaN.  */
  60           __real__ retval = __nanl ("");
  61           __imag__ retval = __nanl ("");
  62         }
  63     }
  64   else if (rcls == FP_INFINITE)
  65     {
  66       /* Real part is infinite.  */
  67       if (icls >= FP_ZERO)
  68         {
  69           /* Imaginary part is finite.  */
  70           long double value = signbit (__real__ x) ? 0.0 : HUGE_VALL;
  71
  72           if (icls == FP_ZERO)
  73             {
  74               /* Imaginary part is 0.0.  */
  75               __real__ retval = value;
  76               __imag__ retval = __imag__ x;
  77             }
  78           else
  79             {
  80               long double sinix, cosix;
  81
  82               __sincosl (__imag__ x, &sinix, &cosix);
  83
  84               __real__ retval = __copysignl (value, cosix);
  85               __imag__ retval = __copysignl (value, sinix);
  86             }
  87         }
  88       else if (signbit (__real__ x) == 0)
  89         {
  90           __real__ retval = HUGE_VALL;
  91           __imag__ retval = __nanl ("");
  92         }
  93       else
  94         {
  95           __real__ retval = 0.0;
  96           __imag__ retval = __copysignl (0.0, __imag__ x);
  97         }
  98     }
  99   else
 100     {
 101       /* If the real part is NaN the result is NaN + iNaN.  */
 102       __real__ retval = __nanl ("");
 103       __imag__ retval = __nanl ("");
 104     }
 105
 106   return retval;
 107 }
 108 weak_alias (__cexpl, cexpl)