math/s_cacosh_template.c

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