libquadmath/math/casinq.c

   1 /* Return arc sine of a complex float type.
   2    Copyright (C) 1997-2018 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 "quadmath-imp.h"
  21
  22 __complex128
  23 casinq (__complex128 x)
  24 {
  25   __complex128 res;
  26
  27   if (isnanq (__real__ x) || isnanq (__imag__ x))
  28     {
  29       if (__real__ x == 0)
  30         {
  31           res = x;
  32         }
  33       else if (isinfq (__real__ x) || isinfq (__imag__ x))
  34         {
  35           __real__ res = nanq ("");
  36           __imag__ res = copysignq (HUGE_VALQ, __imag__ x);
  37         }
  38       else
  39         {
  40           __real__ res = nanq ("");
  41           __imag__ res = nanq ("");
  42         }
  43     }
  44   else
  45     {
  46       __complex128 y;
  47
  48       __real__ y = -__imag__ x;
  49       __imag__ y = __real__ x;
  50
  51       y = casinhq (y);
  52
  53       __real__ res = __imag__ y;
  54       __imag__ res = -__real__ y;
  55     }
  56
  57   return res;
  58 }