math/s_cexpf.c

   1 /* Return value of complex exponential function for float complex value.
   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 #include <math_private.h>
  24
  25
  26 __complex__ float
  27 __cexpf (__complex__ float x)
  28 {
  29   __complex__ float retval;
  30   int rcls = fpclassify (__real__ x);
  31   int icls = fpclassify (__imag__ x);
  32
  33   if (__builtin_expect (rcls >= FP_ZERO, 1))
  34     {
  35       /* Real part is finite.  */
  36       if (__builtin_expect (icls >= FP_ZERO, 1))
  37         {
  38           /* Imaginary part is finite.  */
  39           float exp_val = __ieee754_expf (__real__ x);
  40           float sinix, cosix;
  41
  42           __sincosf (__imag__ x, &sinix, &cosix);
  43
  44           if (isfinite (exp_val))
  45             {
  46               __real__ retval = exp_val * cosix;
  47               __imag__ retval = exp_val * sinix;
  48             }
  49           else
  50             {
  51               __real__ retval = __copysignf (exp_val, cosix);
  52               __imag__ retval = __copysignf (exp_val, sinix);
  53             }
  54         }
  55       else
  56         {
  57           /* If the imaginary part is +-inf or NaN and the real part
  58              is not +-inf the result is NaN + iNaN.  */
  59           __real__ retval = __nanf ("");
  60           __imag__ retval = __nanf ("");
  61
  62           feraiseexcept (FE_INVALID);
  63         }
  64     }
  65   else if (__builtin_expect (rcls == FP_INFINITE, 1))
  66     {
  67       /* Real part is infinite.  */
  68       if (__builtin_expect (icls >= FP_ZERO, 1))
  69         {
  70           /* Imaginary part is finite.  */
  71           float value = signbit (__real__ x) ? 0.0 : HUGE_VALF;
  72
  73           if (icls == FP_ZERO)
  74             {
  75               /* Imaginary part is 0.0.  */
  76               __real__ retval = value;
  77               __imag__ retval = __imag__ x;
  78             }
  79           else
  80             {
  81               float sinix, cosix;
  82
  83               __sincosf (__imag__ x, &sinix, &cosix);
  84
  85               __real__ retval = __copysignf (value, cosix);
  86               __imag__ retval = __copysignf (value, sinix);
  87             }
  88         }
  89       else if (signbit (__real__ x) == 0)
  90         {
  91           __real__ retval = HUGE_VALF;
  92           __imag__ retval = __nanf ("");
  93
  94           if (icls == FP_INFINITE)
  95             feraiseexcept (FE_INVALID);
  96         }
  97       else
  98         {
  99           __real__ retval = 0.0;
 100           __imag__ retval = __copysignf (0.0, __imag__ x);
 101         }
 102     }
 103   else
 104     {
 105       /* If the real part is NaN the result is NaN + iNaN.  */
 106       __real__ retval = __nanf ("");
 107       __imag__ retval = __nanf ("");
 108
 109       if (rcls != FP_NAN || icls != FP_NAN)
 110         feraiseexcept (FE_INVALID);
 111     }
 112
 113   return retval;
 114 }
 115 #ifndef __cexpf
 116 weak_alias (__cexpf, cexpf)
 117 #endif