libm/x86_64/feupdateenv.c

   1 /* Install given floating-point environment and raise exceptions.
   2    Copyright (C) 1997-2017 Free Software Foundation, Inc.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv.h>
  20
  21 int
  22 feupdateenv (const fenv_t *envp)
  23 {
  24   fexcept_t temp;
  25   unsigned int xtemp;
  26
  27   /* Save current exceptions.  */
  28   __asm__ ("fnstsw %0\n\tstmxcsr %1" : "=m" (*&temp), "=m" (xtemp));
  29   temp = (temp | xtemp) & FE_ALL_EXCEPT;
  30
  31   /* Install new environment.  */
  32   fesetenv (envp);
  33
  34   /* Raise the saved exception.  Incidently for us the implementation
  35      defined format of the values in objects of type fexcept_t is the
  36      same as the ones specified using the FE_* constants.  */
  37   feraiseexcept ((int) temp);
  38
  39   /* Success.  */
  40   return 0;
  41 }