Back to index

glibc  2.9
feupdateenv.c
Go to the documentation of this file.
00001 /* Install given floating-point environment and raise exceptions.
00002    Copyright (C) 1997,99,2000,01,07 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 <bp-sym.h>
00023 #include <unistd.h>
00024 #include <dl-procinfo.h>
00025 #include <ldsodefs.h>
00026 
00027 int
00028 __feupdateenv (const fenv_t *envp)
00029 {
00030   fexcept_t temp;
00031   unsigned int xtemp = 0;
00032 
00033   /* Save current exceptions.  */
00034   __asm__ ("fnstsw %0" : "=m" (*&temp));
00035 
00036   /* If the CPU supports SSE we test the MXCSR as well.  */
00037   if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
00038     __asm__ ("stmxcsr %0" : "=m" (*&xtemp));
00039 
00040   temp = (temp | xtemp) & FE_ALL_EXCEPT;
00041 
00042   /* Install new environment.  */
00043   fesetenv (envp);
00044 
00045   /* Raise the saved exception.  Incidently for us the implementation
00046      defined format of the values in objects of type fexcept_t is the
00047      same as the ones specified using the FE_* constants.  */
00048   feraiseexcept ((int) temp);
00049 
00050   /* Success.  */
00051   return 0;
00052 }
00053 
00054 #include <shlib-compat.h>
00055 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
00056 strong_alias (__feupdateenv, __old_feupdateenv)
00057 compat_symbol (libm, BP_SYM (__old_feupdateenv), BP_SYM (feupdateenv), GLIBC_2_1);
00058 #endif
00059 
00060 versioned_symbol (libm, BP_SYM (__feupdateenv), BP_SYM (feupdateenv), GLIBC_2_2);