uclibc-ng/libm/x86_64/feupdateenv.c

/* Install given floating-point environment and raise exceptions.
   Copyright (C) 1997-2017 Free Software Foundation, Inc.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <fenv.h>

int
feupdateenv (const fenv_t *envp)
{
  fexcept_t temp;
  unsigned int xtemp;

  /* Save current exceptions.  */
  __asm__ ("fnstsw %0\n\tstmxcsr %1" : "=m" (*&temp), "=m" (xtemp));
  temp = (temp | xtemp) & FE_ALL_EXCEPT;

  /* Install new environment.  */
  fesetenv (envp);

  /* Raise the saved exception.  Incidently for us the implementation
     defined format of the values in objects of type fexcept_t is the
     same as the ones specified using the FE_* constants.  */
  feraiseexcept ((int) temp);

  /* Success.  */
  return 0;
}