math/s_casin_template.c

   1 /* Return arc sine of a complex float type.
   2    Copyright (C) 1997-2017 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 <math.h>
  22 #include <math_private.h>
  23
  24
  25 CFLOAT
  26 M_DECL_FUNC (__casin) (CFLOAT x)
  27 {
  28   CFLOAT res;
  29
  30   if (isnan (__real__ x) || isnan (__imag__ x))
  31     {
  32       if (__real__ x == 0)
  33         {
  34           res = x;
  35         }
  36       else if (isinf (__real__ x) || isinf (__imag__ x))
  37         {
  38           __real__ res = M_NAN;
  39           __imag__ res = M_COPYSIGN (M_HUGE_VAL, __imag__ x);
  40         }
  41       else
  42         {
  43           __real__ res = M_NAN;
  44           __imag__ res = M_NAN;
  45         }
  46     }
  47   else
  48     {
  49       CFLOAT y;
  50
  51       __real__ y = -__imag__ x;
  52       __imag__ y = __real__ x;
  53
  54       y = M_SUF (__casinh) (y);
  55
  56       __real__ res = __imag__ y;
  57       __imag__ res = -__real__ y;
  58     }
  59
  60   return res;
  61 }
  62
  63 declare_mgen_alias (__casin, casin)
  64
  65 #if M_LIBM_NEED_COMPAT (casin)
  66 declare_mgen_libm_compat (__casin, casin)
  67 #endif