sysdeps/libm-ieee754/s_csin.c

   1 /* Complex sine function for double.
   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
  25 __complex__ double
  26 __csin (__complex__ double x)
  27 {
  28   __complex__ double res;
  29
  30   if (!isfinite (__real__ x) || isnan (__imag__ x))
  31     {
  32       if (__real__ x == 0.0 || __imag__ x == 0.0)
  33         {
  34           __real__ res = __nan ("");
  35           __imag__ res = 0.0;
  36         }
  37       else if (__isinf (__imag__ x))
  38         {
  39           __real__ res = __nan ("");
  40           __imag__ res = __imag__ x;
  41         }
  42       else
  43         {
  44           __real__ res = __nan ("");
  45           __imag__ res = __nan ("");
  46         }
  47     }
  48   else
  49     {
  50       __complex__ double y;
  51
  52       __real__ y = -__imag__ x;
  53       __imag__ y = __real__ x;
  54
  55       y = __csinh (y);
  56
  57       __real__ res = __imag__ y;
  58       __imag__ res = -__real__ y;
  59     }
  60
  61   return res;
  62 }
  63 weak_alias (__csin, csin)
  64 #ifdef NO_LONG_DOUBLE
  65 strong_alias (__csin, __csinl)
  66 weak_alias (__csin, csinl)
  67 #endif