math/s_ccosh.c

   1 /* Complex cosine 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 Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the 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    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    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 __ccosh (__complex__ double x)
  30 {
  31   __complex__ double retval;
  32   int rcls = fpclassify (__real__ x);
  33   int icls = fpclassify (__imag__ x);
  34
  35   if (rcls >= FP_ZERO)
  36     {
  37       /* Real part is finite.  */
  38       if (icls >= FP_ZERO)
  39         {
  40           /* Imaginary part is finite.  */
  41           double sinh_val = __ieee754_sinh (__real__ x);
  42           double cosh_val = __ieee754_cosh (__real__ x);
  43           double sinix, cosix;
  44
  45           __sincos (__imag__ x, &sinix, &cosix);
  46
  47           __real__ retval = cosh_val * cosix;
  48           __imag__ retval = sinh_val * sinix;
  49         }
  50       else
  51         {
  52           __imag__ retval = __real__ x == 0.0 ? 0.0 : __nan ("");
  53           __real__ retval = __nan ("") + __nan ("");
  54
  55 #ifdef FE_INVALID
  56           if (icls == FP_INFINITE)
  57             feraiseexcept (FE_INVALID);
  58 #endif
  59         }
  60     }
  61   else if (rcls == FP_INFINITE)
  62     {
  63       /* Real part is infinite.  */
  64       if (icls == FP_ZERO)
  65         {
  66           /* Imaginary part is 0.0.  */
  67           __real__ retval = HUGE_VAL;
  68           __imag__ retval = __imag__ x * __copysign (1.0, __real__ x);
  69         }
  70       else if (icls > FP_ZERO)
  71         {
  72           /* Imaginary part is finite.  */
  73           double sinix, cosix;
  74
  75           __sincos (__imag__ x, &sinix, &cosix);
  76
  77           __real__ retval = __copysign (HUGE_VAL, cosix);
  78           __imag__ retval = (__copysign (HUGE_VAL, sinix)
  79                              * __copysign (1.0, __real__ x));
  80         }
  81       else
  82         {
  83           /* The addition raises the invalid exception.  */
  84           __real__ retval = HUGE_VAL;
  85           __imag__ retval = __nan ("") + __nan ("");
  86
  87 #ifdef FE_INVALID
  88           if (icls == FP_INFINITE)
  89             feraiseexcept (FE_INVALID);
  90 #endif
  91         }
  92     }
  93   else
  94     {
  95       __real__ retval = __nan ("");
  96       __imag__ retval = __imag__ x == 0.0 ? __imag__ x : __nan ("");
  97     }
  98
  99   return retval;
 100 }
 101 weak_alias (__ccosh, ccosh)
 102 #ifdef NO_LONG_DOUBLE
 103 strong_alias (__ccosh, __ccoshl)
 104 weak_alias (__ccosh, ccoshl)
 105 #endif