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glibc  2.9
feupdateenv.c
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00001 /* Install given floating-point environment and raise exceptions.
00002    Copyright (C) 2000 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by David Huggins-Daines <dhd@debian.org>, 2000
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 <string.h>
00023 
00024 int
00025 feupdateenv (const fenv_t *envp)
00026 {
00027   union { unsigned long long l; unsigned int sw[2]; } s;
00028   fenv_t temp;
00029   /* Get the current exception status */
00030   __asm__ ("fstd %%fr0,0(%1)       \n\t" 
00031            "fldd 0(%1),%%fr0       \n\t" 
00032           : "=m" (s.l) : "r" (&s.l));
00033   memcpy(&temp, envp, sizeof(fenv_t));
00034   /* Currently raised exceptions not cleared */
00035   temp.__status_word |= s.sw[0] & (FE_ALL_EXCEPT << 27);
00036   /* Install new environment.  */
00037   fesetenv (&temp);
00038   /* Success.  */
00039   return 0;
00040 }