math/s_cacosh_template.c

   1 /* Return arc hyperbolic cosine for a complex 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 (__cacosh) (CFLOAT x)
  25 {
  26   CFLOAT res;
  27   int rcls = fpclassify (__real__ x);
  28   int icls = fpclassify (__imag__ x);
  29
  30   if (rcls <= FP_INFINITE || icls <= FP_INFINITE)
  31     {
  32       if (icls == FP_INFINITE)
  33         {
  34           __real__ res = M_HUGE_VAL;
  35
  36           if (rcls == FP_NAN)
  37             __imag__ res = M_NAN;
  38           else
  39             __imag__ res = M_COPYSIGN ((rcls == FP_INFINITE
  40                                         ? (__real__ x < 0
  41                                            ? M_MLIT (M_PI) - M_MLIT (M_PI_4)
  42                                            : M_MLIT (M_PI_4))
  43                                         : M_MLIT (M_PI_2)), __imag__ x);
  44         }
  45       else if (rcls == FP_INFINITE)
  46         {
  47           __real__ res = M_HUGE_VAL;
  48
  49           if (icls >= FP_ZERO)
  50             __imag__ res = M_COPYSIGN (signbit (__real__ x)
  51                                        ? M_MLIT (M_PI) : 0, __imag__ x);
  52           else
  53             __imag__ res = M_NAN;
  54         }
  55       else
  56         {
  57           __real__ res = M_NAN;
  58           if (rcls == FP_ZERO)
  59             __imag__ res = M_MLIT (M_PI_2);
  60           else
  61             __imag__ res = M_NAN;
  62         }
  63     }
  64   else if (rcls == FP_ZERO && icls == FP_ZERO)
  65     {
  66       __real__ res = 0;
  67       __imag__ res = M_COPYSIGN (M_MLIT (M_PI_2), __imag__ x);
  68     }
  69   else
  70     {
  71       CFLOAT y;
  72
  73       __real__ y = -__imag__ x;
  74       __imag__ y = __real__ x;
  75
  76       y = M_SUF (__kernel_casinh) (y, 1);
  77
  78       if (signbit (__imag__ x))
  79         {
  80           __real__ res = __real__ y;
  81           __imag__ res = -__imag__ y;
  82         }
  83       else
  84         {
  85           __real__ res = -__real__ y;
  86           __imag__ res = __imag__ y;
  87         }
  88     }
  89
  90   return res;
  91 }
  92
  93 declare_mgen_alias (__cacosh, cacosh)