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glibc  2.9
fclrexcpt.c
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00001 /* Clear given exceptions in current floating-point environment.
00002    Copyright (C) 1998, 1999, 2000, 2002 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by Andreas Jaeger <aj@suse.de>, 1998.
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 <fenv_libc.h>
00023 #include <fpu_control.h>
00024 
00025 int
00026 feclearexcept (int excepts)
00027 {
00028   int cw;
00029 
00030   /* Mask out unsupported bits/exceptions.  */
00031   excepts &= FE_ALL_EXCEPT;
00032 
00033   /* Read the complete control word.  */
00034   _FPU_GETCW (cw);
00035 
00036   /* Clear exception flag bits and cause bits. If the cause bit is not
00037      cleared, the next CTC instruction (just below) will re-generate the
00038      exception.  */
00039 
00040   cw &= ~(excepts | (excepts << CAUSE_SHIFT));
00041 
00042   /* Put the new data in effect.  */
00043   _FPU_SETCW (cw);
00044 
00045   /* Success.  */
00046   return 0;
00047 }