libquadmath/math/ccoshq.c

   1 /* Complex cosine hyperbole function for complex __float128.
   2    Copyright (C) 1997-2012 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 #ifdef HAVE_FENV_H
  23 # include <fenv.h>
  24 #endif
  25
  26
  27 __complex128
  28 ccoshq (__complex128 x)
  29 {
  30   __complex128 retval;
  31   int rcls = fpclassifyq (__real__ x);
  32   int icls = fpclassifyq (__imag__ x);
  33
  34   if (__builtin_expect (rcls >= QUADFP_ZERO, 1))
  35     {
  36       /* Real part is finite.  */
  37       if (__builtin_expect (icls >= QUADFP_ZERO, 1))
  38         {
  39           /* Imaginary part is finite.  */
  40           const int t = (int) ((FLT128_MAX_EXP - 1) * M_LN2q);
  41           __float128 sinix, cosix;
  42
  43           if (__builtin_expect (icls != QUADFP_SUBNORMAL, 1))
  44             {
  45               sincosq (__imag__ x, &sinix, &cosix);
  46             }
  47           else
  48             {
  49               sinix = __imag__ x;
  50               cosix = 1.0Q;
  51             }
  52
  53           if (fabsq (__real__ x) > t)
  54             {
  55               __float128 exp_t = expq (t);
  56               __float128 rx = fabsq (__real__ x);
  57               if (signbitq (__real__ x))
  58                 sinix = -sinix;
  59               rx -= t;
  60               sinix *= exp_t / 2.0Q;
  61               cosix *= exp_t / 2.0Q;
  62               if (rx > t)
  63                 {
  64                   rx -= t;
  65                   sinix *= exp_t;
  66                   cosix *= exp_t;
  67                 }
  68               if (rx > t)
  69                 {
  70                   /* Overflow (original real part of x > 3t).  */
  71                   __real__ retval = FLT128_MAX * cosix;
  72                   __imag__ retval = FLT128_MAX * sinix;
  73                 }
  74               else
  75                 {
  76                   __float128 exp_val = expq (rx);
  77                   __real__ retval = exp_val * cosix;
  78                   __imag__ retval = exp_val * sinix;
  79                 }
  80             }
  81           else
  82             {
  83               __real__ retval = coshq (__real__ x) * cosix;
  84               __imag__ retval = sinhq (__real__ x) * sinix;
  85             }
  86         }
  87       else
  88         {
  89           __imag__ retval = __real__ x == 0.0Q ? 0.0Q : nanq ("");
  90           __real__ retval = nanq ("") + nanq ("");
  91
  92 #ifdef HAVE_FENV_H
  93           if (icls == QUADFP_INFINITE)
  94             feraiseexcept (FE_INVALID);
  95 #endif
  96         }
  97     }
  98   else if (rcls == QUADFP_INFINITE)
  99     {
 100       /* Real part is infinite.  */
 101       if (__builtin_expect (icls > QUADFP_ZERO, 1))
 102         {
 103           /* Imaginary part is finite.  */
 104           __float128 sinix, cosix;
 105
 106           if (__builtin_expect (icls != QUADFP_SUBNORMAL, 1))
 107             {
 108               sincosq (__imag__ x, &sinix, &cosix);
 109             }
 110           else
 111             {
 112               sinix = __imag__ x;
 113               cosix = 1.0Q;
 114             }
 115
 116           __real__ retval = copysignq (HUGE_VALQ, cosix);
 117           __imag__ retval = (copysignq (HUGE_VALQ, sinix)
 118                              * copysignq (1.0Q, __real__ x));
 119         }
 120       else if (icls == QUADFP_ZERO)
 121         {
 122           /* Imaginary part is 0.0.  */
 123           __real__ retval = HUGE_VALQ;
 124           __imag__ retval = __imag__ x * copysignq (1.0Q, __real__ x);
 125         }
 126       else
 127         {
 128           /* The addition raises the invalid exception.  */
 129           __real__ retval = HUGE_VALQ;
 130           __imag__ retval = nanq ("") + nanq ("");
 131
 132 #ifdef HAVE_FENV_H
 133           if (icls == QUADFP_INFINITE)
 134             feraiseexcept (FE_INVALID);
 135 #endif
 136          }
 137     }
 138   else
 139     {
 140       __real__ retval = nanq ("");
 141       __imag__ retval = __imag__ x == 0.0 ? __imag__ x : nanq ("");
 142     }
 143
 144   return retval;
 145 }