sysdeps/i386/fpu/feupdateenv.c

   1 /* Install given floating-point environment and raise exceptions.
   2    Copyright (C) 1997-2014 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 <fenv.h>
  21 #include <unistd.h>
  22 #include <dl-procinfo.h>
  23 #include <ldsodefs.h>
  24
  25 int
  26 __feupdateenv (const fenv_t *envp)
  27 {
  28   fexcept_t temp;
  29   unsigned int xtemp = 0;
  30
  31   /* Save current exceptions.  */
  32   __asm__ ("fnstsw %0" : "=m" (*&temp));
  33
  34   /* If the CPU supports SSE we test the MXCSR as well.  */
  35   if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
  36     __asm__ ("stmxcsr %0" : "=m" (*&xtemp));
  37
  38   temp = (temp | xtemp) & FE_ALL_EXCEPT;
  39
  40   /* Install new environment.  */
  41   fesetenv (envp);
  42
  43   /* Raise the saved exception.  Incidently for us the implementation
  44      defined format of the values in objects of type fexcept_t is the
  45      same as the ones specified using the FE_* constants.  */
  46   __feraiseexcept ((int) temp);
  47
  48   /* Success.  */
  49   return 0;
  50 }
  51
  52 #include <shlib-compat.h>
  53 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  54 strong_alias (__feupdateenv, __old_feupdateenv)
  55 compat_symbol (libm, __old_feupdateenv, feupdateenv, GLIBC_2_1);
  56 #endif
  57
  58 libm_hidden_ver (__feupdateenv, feupdateenv)
  59 versioned_symbol (libm, __feupdateenv, feupdateenv, GLIBC_2_2);