sysdeps/i386/fpu/fsetexcptflg.c

   1 /* Set floating-point environment exception handling.
   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 <math.h>
  22 #include <unistd.h>
  23 #include <ldsodefs.h>
  24 #include <dl-procinfo.h>
  25
  26 int
  27 __fesetexceptflag (const fexcept_t *flagp, int excepts)
  28 {
  29   fenv_t temp;
  30
  31   /* Get the current environment.  We have to do this since we cannot
  32      separately set the status word.  */
  33   __asm__ ("fnstenv %0" : "=m" (*&temp));
  34
  35   temp.__status_word &= ~(excepts & FE_ALL_EXCEPT);
  36   temp.__status_word |= *flagp & excepts & FE_ALL_EXCEPT;
  37
  38   /* Store the new status word (along with the rest of the environment.
  39      Possibly new exceptions are set but they won't get executed unless
  40      the next floating-point instruction.  */
  41   __asm__ ("fldenv %0" : : "m" (*&temp));
  42
  43   /* If the CPU supports SSE, we set the MXCSR as well.  */
  44   if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
  45     {
  46       unsigned int xnew_exc;
  47
  48       /* Get the current MXCSR.  */
  49       __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
  50
  51       /* Set the relevant bits.  */
  52       xnew_exc &= ~(excepts & FE_ALL_EXCEPT);
  53       xnew_exc |= *flagp & excepts & FE_ALL_EXCEPT;
  54
  55       /* Put the new data in effect.  */
  56       __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
  57     }
  58
  59   /* Success.  */
  60   return 0;
  61 }
  62
  63 #include <shlib-compat.h>
  64 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  65 strong_alias (__fesetexceptflag, __old_fesetexceptflag)
  66 compat_symbol (libm, __old_fesetexceptflag, fesetexceptflag, GLIBC_2_1);
  67 #endif
  68
  69 versioned_symbol (libm, __fesetexceptflag, fesetexceptflag, GLIBC_2_2);