math/s_casinl.c

   1 /* Return arc sine of complex long double 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, 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 <math.h>
  23 #include <math_private.h>
  24
  25
  26 __complex__ long double
  27 __casinl (__complex__ long double x)
  28 {
  29   __complex__ long double res;
  30
  31   if (isnan (__real__ x) || isnan (__imag__ x))
  32     {
  33       if (__real__ x == 0.0)
  34         {
  35           res = x;
  36         }
  37       else if (__isinf_nsl (__real__ x) || __isinf_nsl (__imag__ x))
  38         {
  39           __real__ res = __nanl ("");
  40           __imag__ res = __copysignl (HUGE_VALL, __imag__ x);
  41         }
  42       else
  43         {
  44           __real__ res = __nanl ("");
  45           __imag__ res = __nanl ("");
  46         }
  47     }
  48   else
  49     {
  50       __complex__ long double y;
  51
  52       __real__ y = -__imag__ x;
  53       __imag__ y = __real__ x;
  54
  55       y = __casinhl (y);
  56
  57       __real__ res = __imag__ y;
  58       __imag__ res = -__real__ y;
  59     }
  60
  61   return res;
  62 }
  63 weak_alias (__casinl, casinl)