1: /* Return arc sine of complex double 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 <complex.h>
   22: #include <math.h>
   23: 
   24: 
   25: __complex__ double
   26: __casin (__complex__ double x)
   27: {
   28:   __complex__ double res;
   29: 
   30:   if (isnan (__real__ x) || isnan (__imag__ x))
   31:     {
   32:       if (__real__ x == 0.0)
   33:         {
   34:           res = x;
   35:         }
   36:       else if (__isinf (__real__ x) || __isinf (__imag__ x))
   37:         {
   38:           __real__ res = __nan ("");
   39:           __imag__ res = __copysign (HUGE_VAL, __imag__ x);
   40:         }
   41:       else
   42:         {
   43:           __real__ res = __nan ("");
   44:           __imag__ res = __nan ("");
   45:         }
   46:     }
   47:   else
   48:     {
   49:       __complex__ double y;
   50: 
   51:       __real__ y = -__imag__ x;
   52:       __imag__ y = __real__ x;
   53: 
   54:       y = __casinh (y);
   55: 
   56:       __real__ res = __imag__ y;
   57:       __imag__ res = -__real__ y;
   58:     }
   59: 
   60:   return res;
   61: }
   62: weak_alias (__casin, casin)
   63: #ifdef NO_LONG_DOUBLE
   64: strong_alias (__casin, __casinl)
   65: weak_alias (__casin, casinl)
   66: #endif