libquadmath/math/casinq.c

   1 /* Return arc sine of complex __float128 value.
   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 "quadmath-imp.h"
  22
  23
  24 __complex128
  25 casinq (__complex128 x)
  26 {
  27   __complex128 res;
  28
  29   if (isnanq (__real__ x) || isnanq (__imag__ x))
  30     {
  31       if (__real__ x == 0.0)
  32         {
  33           res = x;
  34         }
  35       else if (isinfq (__real__ x) || isinfq (__imag__ x))
  36         {
  37           __real__ res = nanq ("");
  38           __imag__ res = copysignq (HUGE_VALQ, __imag__ x);
  39         }
  40       else
  41         {
  42           __real__ res = nanq ("");
  43           __imag__ res = nanq ("");
  44         }
  45     }
  46   else
  47     {
  48       __complex128 y;
  49
  50       __real__ y = -__imag__ x;
  51       __imag__ y = __real__ x;
  52
  53       y = casinhq (y);
  54
  55       __real__ res = __imag__ y;
  56       __imag__ res = -__real__ y;
  57     }
  58
  59   return res;
  60 }