math/s_casin_template.c

   1 /* Return arc sine of a complex float type.
   2    Copyright (C) 1997-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <complex.h>
  20 #include <math.h>
  21
  22
  23 CFLOAT
  24 M_DECL_FUNC (__casin) (CFLOAT x)
  25 {
  26   CFLOAT res;
  27
  28   if (isnan (__real__ x) || isnan (__imag__ x))
  29     {
  30       if (__real__ x == 0)
  31         {
  32           res = x;
  33         }
  34       else if (isinf (__real__ x) || isinf (__imag__ x))
  35         {
  36           __real__ res = M_NAN;
  37           __imag__ res = M_COPYSIGN (M_HUGE_VAL, __imag__ x);
  38         }
  39       else
  40         {
  41           __real__ res = M_NAN;
  42           __imag__ res = M_NAN;
  43         }
  44     }
  45   else
  46     {
  47       CFLOAT y;
  48
  49       __real__ y = -__imag__ x;
  50       __imag__ y = __real__ x;
  51
  52       y = M_SUF (__casinh) (y);
  53
  54       __real__ res = __imag__ y;
  55       __imag__ res = -__real__ y;
  56     }
  57
  58   return res;
  59 }
  60
  61 declare_mgen_alias (__casin, casin)