libstdc++-v3/math/csinh.c

   1 /* Complex sine hyperbole function for double. */
   2
   3 /* Copyright (C) 1997-1999 Free Software Foundation, Inc.
   4
   5    This file is part of the GNU ISO C++ Library.  This library is free
   6    software; you can redistribute it and/or modify it under the
   7    terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This 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
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License along
  17    with this library; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19    USA.
  20
  21    As a special exception, you may use this file as part of a free software
  22    library without restriction.  Specifically, if other files instantiate
  23    templates or use macros or inline functions from this file, or you compile
  24    this file and link it with other files to produce an executable, this
  25    file does not by itself cause the resulting executable to be covered by
  26    the GNU General Public License.  This exception does not however
  27    invalidate any other reasons why the executable file might be covered by
  28    the GNU General Public License.  */
  29
  30
  31 #include <math.h>
  32 #include "mathconf.h"
  33
  34
  35 __complex__ double
  36 csinh (__complex__ double x)
  37 {
  38   __complex__ double retval;
  39   int negate = signbit (__real__ x);
  40
  41   __real__ x = fabs (__real__ x);
  42
  43   if (FINITE_P (__real__ x))
  44     {
  45       /* Real part is finite.  */
  46       if (FINITE_P (__imag__ x))
  47         {
  48           /* Imaginary part is finite.  */
  49           double sinh_val = sinh (__real__ x);
  50           double cosh_val = cosh (__real__ x);
  51           double sinix = sin (__imag__ x);
  52           double cosix = cos (__imag__ x);
  53
  54           __real__ retval = sinh_val * cosix;
  55           __imag__ retval = cosh_val * sinix;
  56
  57           if (negate)
  58             __real__ retval = -__real__ retval;
  59         }
  60       else
  61         {
  62           if (__real__ x == 0.0)
  63             {
  64               /* Real part is 0.0.  */
  65               __real__ retval = copysign (0.0, negate ? -1.0 : 1.0);
  66               __imag__ retval = NAN + NAN;
  67             }
  68           else
  69             {
  70               __real__ retval = NAN;
  71               __imag__ retval = NAN;
  72             }
  73         }
  74     }
  75   else if (INFINITE_P (__real__ x))
  76     {
  77       /* Real part is infinite.  */
  78       if (__imag__ x == 0.0)
  79         {
  80           /* Imaginary part is 0.0.  */
  81           __real__ retval = negate ? -HUGE_VAL : HUGE_VAL;
  82           __imag__ retval = __imag__ x;
  83         }
  84       else if (FINITE_P (__imag__ x))
  85         {
  86           /* Imaginary part is finite.  */
  87           double sinix = sin (__imag__ x);
  88           double cosix = cos (__imag__ x);
  89
  90           __real__ retval = copysign (HUGE_VAL, cosix);
  91           __imag__ retval = copysign (HUGE_VAL, sinix);
  92
  93           if (negate)
  94             __real__ retval = -__real__ retval;
  95         }
  96       else
  97         {
  98           /* The addition raises the invalid exception.  */
  99           __real__ retval = HUGE_VAL;
 100           __imag__ retval = NAN + NAN;
 101         }
 102     }
 103   else
 104     {
 105       __real__ retval = NAN;
 106       __imag__ retval = __imag__ x == 0.0 ? __imag__ x : NAN;
 107     }
 108
 109   return retval;
 110 }