sysdeps/libm-ieee754/s_csinh.c

   1 /* Complex sine hyperbole 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 <fenv.h>
  23 #include <math.h>
  24
  25 #include "math_private.h"
  26
  27
  28 __complex__ double
  29 __csinh (__complex__ double x)
  30 {
  31   __complex__ double retval;
  32   int negate = signbit (__real__ x);
  33   int rcls = fpclassify (__real__ x);
  34   int icls = fpclassify (__imag__ x);
  35
  36   __real__ x = fabs (__real__ x);
  37
  38   if (rcls >= FP_ZERO)
  39     {
  40       /* Real part is finite.  */
  41       if (icls >= FP_ZERO)
  42         {
  43           /* Imaginary part is finite.  */
  44           double sinh_val = __ieee754_sinh (__real__ x);
  45           double cosh_val = __ieee754_cosh (__real__ x);
  46           double sinix, cosix;
  47
  48           __sincos (__imag__ x, &sinix, &cosix);
  49
  50           __real__ retval = sinh_val * cosix;
  51           __imag__ retval = cosh_val * sinix;
  52
  53           if (negate)
  54             __real__ retval = -__real__ retval;
  55         }
  56       else
  57         {
  58           if (rcls == FP_ZERO)
  59             {
  60               /* Real part is 0.0.  */
  61               __real__ retval = __copysign (0.0, negate ? -1.0 : 1.0);
  62               __imag__ retval = __nan ("") + __nan ("");
  63
  64 #ifdef FE_INVALID
  65               if (icls == FP_INFINITE)
  66                 feraiseexcept (FE_INVALID);
  67 #endif
  68             }
  69           else
  70             {
  71               __real__ retval = __nan ("");
  72               __imag__ retval = __nan ("");
  73
  74 #ifdef FE_INVALID
  75               feraiseexcept (FE_INVALID);
  76 #endif
  77             }
  78         }
  79     }
  80   else if (rcls == FP_INFINITE)
  81     {
  82       /* Real part is infinite.  */
  83       if (icls == FP_ZERO)
  84         {
  85           /* Imaginary part is 0.0.  */
  86           __real__ retval = negate ? -HUGE_VAL : HUGE_VAL;
  87           __imag__ retval = __imag__ x;
  88         }
  89       else if (icls > FP_ZERO)
  90         {
  91           /* Imaginary part is finite.  */
  92           double sinix, cosix;
  93
  94           __sincos (__imag__ x, &sinix, &cosix);
  95
  96           __real__ retval = __copysign (HUGE_VAL, cosix);
  97           __imag__ retval = __copysign (HUGE_VAL, sinix);
  98
  99           if (negate)
 100             __real__ retval = -__real__ retval;
 101         }
 102       else
 103         {
 104           /* The addition raises the invalid exception.  */
 105           __real__ retval = HUGE_VAL;
 106           __imag__ retval = __nan ("") + __nan ("");
 107
 108 #ifdef FE_INVALID
 109           if (icls == FP_INFINITE)
 110             feraiseexcept (FE_INVALID);
 111 #endif
 112         }
 113     }
 114   else
 115     {
 116       __real__ retval = __nan ("");
 117       __imag__ retval = __imag__ x == 0.0 ? __imag__ x : __nan ("");
 118     }
 119
 120   return retval;
 121 }
 122 weak_alias (__csinh, csinh)
 123 #ifdef NO_LONG_DOUBLE
 124 strong_alias (__csinh, __csinhl)
 125 weak_alias (__csinh, csinhl)
 126 #endif