libatomic/fenv.c

   1 /* Copyright (C) 2012-2017 Free Software Foundation, Inc.
   2
   3    This file is part of the GNU Atomic Library (libatomic).
   4
   5    Libatomic is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    Libatomic is distributed in the hope that it will be useful, but WITHOUT ANY
  11    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  12    FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13    more details.
  14
  15    Under Section 7 of GPL version 3, you are granted additional
  16    permissions described in the GCC Runtime Library Exception, version
  17    3.1, as published by the Free Software Foundation.
  18
  19    You should have received a copy of the GNU General Public License and
  20    a copy of the GCC Runtime Library Exception along with this program;
  21    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  22    <http://www.gnu.org/licenses/>.  */
  23
  24 #include "libatomic_i.h"
  25
  26 #ifdef HAVE_FENV_H
  27 # include <fenv.h>
  28 #endif
  29
  30 /* Raise the supported floating-point exceptions from EXCEPTS.  Other
  31    bits in EXCEPTS are ignored.  */
  32
  33 void
  34 __atomic_feraiseexcept (int excepts __attribute__ ((unused)))
  35 {
  36   volatile float r __attribute__ ((unused));
  37 #ifdef FE_INVALID
  38   if (excepts & FE_INVALID)
  39   {
  40     volatile float zero = 0.0f;
  41     r = zero / zero;
  42   }
  43 #endif
  44 #ifdef FE_DIVBYZERO
  45   if (excepts & FE_DIVBYZERO)
  46     {
  47       volatile float zero = 0.0f;
  48       r = 1.0f / zero;
  49     }
  50 #endif
  51 #ifdef FE_OVERFLOW
  52   if (excepts & FE_OVERFLOW)
  53     {
  54       volatile float max = __FLT_MAX__;
  55       r = max * max;
  56     }
  57 #endif
  58 #ifdef FE_UNDERFLOW
  59   if (excepts & FE_UNDERFLOW)
  60     {
  61       volatile float min = __FLT_MIN__;
  62       r = min * min;
  63     }
  64 #endif
  65 #ifdef FE_INEXACT
  66   if (excepts & FE_INEXACT)
  67     {
  68       volatile float three = 3.0f;
  69       r = 1.0f / three;
  70     }
  71 #endif
  72 }