math/s_cacosh_template.c

   1 /* Return arc hyperbolic cosine for a complex type.
   2    Copyright (C) 1997-2021 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    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <complex.h>
  21 #include <math.h>
  22
  23
  24 CFLOAT
  25 M_DECL_FUNC (__cacosh) (CFLOAT x)
  26 {
  27   CFLOAT res;
  28   int rcls = fpclassify (__real__ x);
  29   int icls = fpclassify (__imag__ x);
  30
  31   if (rcls <= FP_INFINITE || icls <= FP_INFINITE)
  32     {
  33       if (icls == FP_INFINITE)
  34         {
  35           __real__ res = M_HUGE_VAL;
  36
  37           if (rcls == FP_NAN)
  38             __imag__ res = M_NAN;
  39           else
  40             __imag__ res = M_COPYSIGN ((rcls == FP_INFINITE
  41                                         ? (__real__ x < 0
  42                                            ? M_MLIT (M_PI) - M_MLIT (M_PI_4)
  43                                            : M_MLIT (M_PI_4))
  44                                         : M_MLIT (M_PI_2)), __imag__ x);
  45         }
  46       else if (rcls == FP_INFINITE)
  47         {
  48           __real__ res = M_HUGE_VAL;
  49
  50           if (icls >= FP_ZERO)
  51             __imag__ res = M_COPYSIGN (signbit (__real__ x)
  52                                        ? M_MLIT (M_PI) : 0, __imag__ x);
  53           else
  54             __imag__ res = M_NAN;
  55         }
  56       else
  57         {
  58           __real__ res = M_NAN;
  59           if (rcls == FP_ZERO)
  60             __imag__ res = M_MLIT (M_PI_2);
  61           else
  62             __imag__ res = M_NAN;
  63         }
  64     }
  65   else if (rcls == FP_ZERO && icls == FP_ZERO)
  66     {
  67       __real__ res = 0;
  68       __imag__ res = M_COPYSIGN (M_MLIT (M_PI_2), __imag__ x);
  69     }
  70   else
  71     {
  72       CFLOAT y;
  73
  74       __real__ y = -__imag__ x;
  75       __imag__ y = __real__ x;
  76
  77       y = M_SUF (__kernel_casinh) (y, 1);
  78
  79       if (signbit (__imag__ x))
  80         {
  81           __real__ res = __real__ y;
  82           __imag__ res = -__imag__ y;
  83         }
  84       else
  85         {
  86           __real__ res = -__real__ y;
  87           __imag__ res = __imag__ y;
  88         }
  89     }
  90
  91   return res;
  92 }
  93
  94 declare_mgen_alias (__cacosh, cacosh)