libquadmath/math/cacoshq.c

   1 /* Return arc hyperbolic cosine for a complex type.
   2    Copyright (C) 1997-2018 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 "quadmath-imp.h"
  21
  22 __complex128
  23 cacoshq (__complex128 x)
  24 {
  25   __complex128 res;
  26   int rcls = fpclassifyq (__real__ x);
  27   int icls = fpclassifyq (__imag__ x);
  28
  29   if (rcls <= QUADFP_INFINITE || icls <= QUADFP_INFINITE)
  30     {
  31       if (icls == QUADFP_INFINITE)
  32         {
  33           __real__ res = HUGE_VALQ;
  34
  35           if (rcls == QUADFP_NAN)
  36             __imag__ res = nanq ("");
  37           else
  38             __imag__ res = copysignq ((rcls == QUADFP_INFINITE
  39                                         ? (__real__ x < 0
  40                                            ? M_PIq - M_PI_4q
  41                                            : M_PI_4q)
  42                                         : M_PI_2q), __imag__ x);
  43         }
  44       else if (rcls == QUADFP_INFINITE)
  45         {
  46           __real__ res = HUGE_VALQ;
  47
  48           if (icls >= QUADFP_ZERO)
  49             __imag__ res = copysignq (signbitq (__real__ x)
  50                                        ? M_PIq : 0, __imag__ x);
  51           else
  52             __imag__ res = nanq ("");
  53         }
  54       else
  55         {
  56           __real__ res = nanq ("");
  57           if (rcls == QUADFP_ZERO)
  58             __imag__ res = M_PI_2q;
  59           else
  60             __imag__ res = nanq ("");
  61         }
  62     }
  63   else if (rcls == QUADFP_ZERO && icls == QUADFP_ZERO)
  64     {
  65       __real__ res = 0;
  66       __imag__ res = copysignq (M_PI_2q, __imag__ x);
  67     }
  68   else
  69     {
  70       __complex128 y;
  71
  72       __real__ y = -__imag__ x;
  73       __imag__ y = __real__ x;
  74
  75       y = __quadmath_kernel_casinhq (y, 1);
  76
  77       if (signbitq (__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 }