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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <complex.h>
  21 #include <fenv.h>
  22 #include <math.h>
  23
  24 #include <math_private.h>
  25
  26
  27 __complex__ double
  28 __csin (__complex__ double x)
  29 {
  30   __complex__ double retval;
  31   int negate = signbit (__real__ x);
  32   int rcls = fpclassify (__real__ x);
  33   int icls = fpclassify (__imag__ x);
  34
  35   __real__ x = fabs (__real__ x);
  36
  37   if (__builtin_expect (icls >= FP_ZERO, 1))
  38     {
  39       /* Imaginary part is finite.  */
  40       if (__builtin_expect (rcls >= FP_ZERO, 1))
  41         {
  42           /* Real part is finite.  */
  43           double sinh_val = __ieee754_sinh (__imag__ x);
  44           double cosh_val = __ieee754_cosh (__imag__ x);
  45           double sinix, cosix;
  46
  47           __sincos (__real__ x, &sinix, &cosix);
  48
  49           __real__ retval = cosh_val * sinix;
  50           __imag__ retval = sinh_val * cosix;
  51
  52           if (negate)
  53             __real__ retval = -__real__ retval;
  54         }
  55       else
  56         {
  57           if (icls == FP_ZERO)
  58             {
  59               /* Imaginary part is 0.0.  */
  60               __real__ retval = __nan ("");
  61               __imag__ retval = __imag__ x;
  62
  63               if (rcls == FP_INFINITE)
  64                 feraiseexcept (FE_INVALID);
  65             }
  66           else
  67             {
  68               __real__ retval = __nan ("");
  69               __imag__ retval = __nan ("");
  70
  71               feraiseexcept (FE_INVALID);
  72             }
  73         }
  74     }
  75   else if (icls == FP_INFINITE)
  76     {
  77       /* Imaginary part is infinite.  */
  78       if (rcls == FP_ZERO)
  79         {
  80           /* Real part is 0.0.  */
  81           __real__ retval = __copysign (0.0, negate ? -1.0 : 1.0);
  82           __imag__ retval = __imag__ x;
  83         }
  84       else if (rcls > FP_ZERO)
  85         {
  86           /* Real part is finite.  */
  87           double sinix, cosix;
  88
  89           __sincos (__real__ x, &sinix, &cosix);
  90
  91           __real__ retval = __copysign (HUGE_VAL, sinix);
  92           __imag__ retval = __copysign (HUGE_VAL, cosix);
  93
  94           if (negate)
  95             __real__ retval = -__real__ retval;
  96           if (signbit (__imag__ x))
  97             __imag__ retval = -__imag__ retval;
  98         }
  99       else
 100         {
 101           /* The addition raises the invalid exception.  */
 102           __real__ retval = __nan ("");
 103           __imag__ retval = HUGE_VAL;
 104
 105           if (rcls == FP_INFINITE)
 106             feraiseexcept (FE_INVALID);
 107         }
 108     }
 109   else
 110     {
 111       if (rcls == FP_ZERO)
 112         __real__ retval = __copysign (0.0, negate ? -1.0 : 1.0);
 113       else
 114         __real__ retval = __nan ("");
 115       __imag__ retval = __nan ("");
 116     }
 117
 118   return retval;
 119 }
 120 weak_alias (__csin, csin)
 121 #ifdef NO_LONG_DOUBLE
 122 strong_alias (__csin, __csinl)
 123 weak_alias (__csin, csinl)
 124 #endif