sysdeps/i386/fpu/fclrexcpt.c

   1 /* Clear given exceptions in current floating-point environment.
   2    Copyright (C) 1997, 1999 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 Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    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    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <fenv.h>
  22
  23 void
  24 feclearexcept (int excepts)
  25 {
  26   fenv_t temp;
  27
  28   /* Mask out unsupported bits/exceptions.  */
  29   excepts &= FE_ALL_EXCEPT;
  30
  31   /* Bah, we have to clear selected exceptions.  Since there is no
  32      `fldsw' instruction we have to do it the hard way.  */
  33   __asm__ ("fnstenv %0" : "=m" (*&temp));
  34
  35   /* Clear the relevant bits.  */
  36   temp.__status_word &= excepts ^ FE_ALL_EXCEPT;
  37
  38   /* Put the new data in effect.  */
  39   __asm__ ("fldenv %0" : : "m" (*&temp));
  40 }