sysdeps/i386/fpu/fsetexcptflg.c

   1 /* Set floating-point environment exception handling.
   2    Copyright (C) 1997,99,2000,01, 2004 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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <fenv.h>
  22 #include <math.h>
  23 #include <bp-sym.h>
  24 #include <unistd.h>
  25 #include <ldsodefs.h>
  26 #include <dl-procinfo.h>
  27
  28 int
  29 __fesetexceptflag (const fexcept_t *flagp, int excepts)
  30 {
  31   fenv_t temp;
  32
  33   /* Get the current environment.  We have to do this since we cannot
  34      separately set the status word.  */
  35   __asm__ ("fnstenv %0" : "=m" (*&temp));
  36
  37   temp.__status_word &= ~(excepts & FE_ALL_EXCEPT);
  38   temp.__status_word |= *flagp & excepts & FE_ALL_EXCEPT;
  39
  40   /* Store the new status word (along with the rest of the environment.
  41      Possibly new exceptions are set but they won't get executed unless
  42      the next floating-point instruction.  */
  43   __asm__ ("fldenv %0" : : "m" (*&temp));
  44
  45   /* If the CPU supports SSE, we set the MXCSR as well.  */
  46   if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
  47     {
  48       unsigned int xnew_exc;
  49
  50       /* Get the current MXCSR.  */
  51       __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
  52
  53       /* Set the relevant bits.  */
  54       xnew_exc &= ~(excepts & FE_ALL_EXCEPT);
  55       xnew_exc |= *flagp & excepts & FE_ALL_EXCEPT;
  56
  57       /* Put the new data in effect.  */
  58       __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
  59     }
  60
  61   /* Success.  */
  62   return 0;
  63 }
  64
  65 #include <shlib-compat.h>
  66 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  67 strong_alias (__fesetexceptflag, __old_fesetexceptflag)
  68 compat_symbol (libm, BP_SYM (__old_fesetexceptflag), BP_SYM (fesetexceptflag), GLIBC_2_1);
  69 #endif
  70
  71 versioned_symbol (libm, BP_SYM (__fesetexceptflag), BP_SYM (fesetexceptflag), GLIBC_2_2);