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glibc  2.9
fsetexcptflg.c
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00001 /* Set floating-point environment exception handling.
00002    Copyright (C) 1997,99,2000,01, 2004 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
00005 
00006    The GNU C Library is free software; you can redistribute it and/or
00007    modify it under the terms of the GNU Lesser General Public
00008    License as published by the Free Software Foundation; either
00009    version 2.1 of the License, or (at your option) any later version.
00010 
00011    The GNU C Library is distributed in the hope that it will be useful,
00012    but WITHOUT ANY WARRANTY; without even the implied warranty of
00013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014    Lesser General Public License for more details.
00015 
00016    You should have received a copy of the GNU Lesser General Public
00017    License along with the GNU C Library; if not, write to the Free
00018    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00019    02111-1307 USA.  */
00020 
00021 #include <fenv.h>
00022 #include <math.h>
00023 #include <bp-sym.h>
00024 #include <unistd.h>
00025 #include <ldsodefs.h>
00026 #include <dl-procinfo.h>
00027 
00028 int
00029 __fesetexceptflag (const fexcept_t *flagp, int excepts)
00030 {
00031   fenv_t temp;
00032 
00033   /* Get the current environment.  We have to do this since we cannot
00034      separately set the status word.  */
00035   __asm__ ("fnstenv %0" : "=m" (*&temp));
00036 
00037   temp.__status_word &= ~(excepts & FE_ALL_EXCEPT);
00038   temp.__status_word |= *flagp & excepts & FE_ALL_EXCEPT;
00039 
00040   /* Store the new status word (along with the rest of the environment.
00041      Possibly new exceptions are set but they won't get executed unless
00042      the next floating-point instruction.  */
00043   __asm__ ("fldenv %0" : : "m" (*&temp));
00044 
00045   /* If the CPU supports SSE, we set the MXCSR as well.  */
00046   if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
00047     {
00048       unsigned int xnew_exc;
00049 
00050       /* Get the current MXCSR.  */
00051       __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
00052 
00053       /* Set the relevant bits.  */
00054       xnew_exc &= ~(excepts & FE_ALL_EXCEPT);
00055       xnew_exc |= *flagp & excepts & FE_ALL_EXCEPT;
00056 
00057       /* Put the new data in effect.  */
00058       __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
00059     }
00060 
00061   /* Success.  */
00062   return 0;
00063 }
00064 
00065 #include <shlib-compat.h>
00066 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
00067 strong_alias (__fesetexceptflag, __old_fesetexceptflag)
00068 compat_symbol (libm, BP_SYM (__old_fesetexceptflag), BP_SYM (fesetexceptflag), GLIBC_2_1);
00069 #endif
00070 
00071 versioned_symbol (libm, BP_SYM (__fesetexceptflag), BP_SYM (fesetexceptflag), GLIBC_2_2);