math/s_csin.c

   1 /* Complex sine function for double.
   2    Copyright (C) 1997, 2011 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 __csin (__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 (__builtin_expect (icls >= FP_ZERO, 1))
  39     {
  40       /* Imaginary part is finite.  */
  41       if (__builtin_expect (rcls >= FP_ZERO, 1))
  42         {
  43           /* Real part is finite.  */
  44           double sinh_val = __ieee754_sinh (__imag__ x);
  45           double cosh_val = __ieee754_cosh (__imag__ x);
  46           double sinix, cosix;
  47
  48           __sincos (__real__ x, &sinix, &cosix);
  49
  50           __real__ retval = cosh_val * sinix;
  51           __imag__ retval = sinh_val * cosix;
  52
  53           if (negate)
  54             __real__ retval = -__real__ retval;
  55         }
  56       else
  57         {
  58           if (icls == FP_ZERO)
  59             {
  60               /* Imaginary part is 0.0.  */
  61               __real__ retval = __nan ("");
  62               __imag__ retval = __imag__ x;
  63
  64               if (rcls == FP_INFINITE)
  65                 feraiseexcept (FE_INVALID);
  66             }
  67           else
  68             {
  69               __real__ retval = __nan ("");
  70               __imag__ retval = __nan ("");
  71
  72               feraiseexcept (FE_INVALID);
  73             }
  74         }
  75     }
  76   else if (icls == FP_INFINITE)
  77     {
  78       /* Imaginary part is infinite.  */
  79       if (rcls == FP_ZERO)
  80         {
  81           /* Real part is 0.0.  */
  82           __real__ retval = __copysign (0.0, negate ? -1.0 : 1.0);
  83           __imag__ retval = __imag__ x;
  84         }
  85       else if (rcls > FP_ZERO)
  86         {
  87           /* Real part is finite.  */
  88           double sinix, cosix;
  89
  90           __sincos (__real__ x, &sinix, &cosix);
  91
  92           __real__ retval = __copysign (HUGE_VAL, sinix);
  93           __imag__ retval = __copysign (HUGE_VAL, cosix);
  94
  95           if (negate)
  96             __real__ retval = -__real__ retval;
  97           if (signbit (__imag__ x))
  98             __imag__ retval = -__imag__ retval;
  99         }
 100       else
 101         {
 102           /* The addition raises the invalid exception.  */
 103           __real__ retval = __nan ("");
 104           __imag__ retval = HUGE_VAL;
 105
 106           if (rcls == FP_INFINITE)
 107             feraiseexcept (FE_INVALID);
 108         }
 109     }
 110   else
 111     {
 112       if (rcls == FP_ZERO)
 113         __real__ retval = __copysign (0.0, negate ? -1.0 : 1.0);
 114       else
 115         __real__ retval = __nan ("");
 116       __imag__ retval = __nan ("");
 117     }
 118
 119   return retval;
 120 }
 121 weak_alias (__csin, csin)
 122 #ifdef NO_LONG_DOUBLE
 123 strong_alias (__csin, __csinl)
 124 weak_alias (__csin, csinl)
 125 #endif