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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, 2004 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by Alexandre Oliva <aoliva@redhat.com>
00005    based on corresponding file in the MIPS port.
00006 
00007    The GNU C Library is free software; you can redistribute it and/or
00008    modify it under the terms of the GNU Lesser General Public
00009    License as published by the Free Software Foundation; either
00010    version 2.1 of the License, or (at your option) any later version.
00011 
00012    The GNU C Library is distributed in the hope that it will be useful,
00013    but WITHOUT ANY WARRANTY; without even the implied warranty of
00014    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015    Lesser General Public License for more details.
00016 
00017    You should have received a copy of the GNU Lesser General Public
00018    License along with the GNU C Library; if not, write to the Free
00019    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00020    02111-1307 USA.  */
00021 
00022 #include <fenv.h>
00023 #include <fenv_libc.h>
00024 #include <fpu_control.h>
00025 #include <shlib-compat.h>
00026 
00027 int
00028 __feclearexcept (int excepts)
00029 {
00030   fpu_control_t cw;
00031 
00032   /* Mask out unsupported bits/exceptions.  */
00033   excepts &= FE_ALL_EXCEPT;
00034 
00035   /* Read the complete control word.  */
00036   _FPU_GETCW (cw);
00037 
00038   /* Clear exception flag bits and cause bits.  EF bits are cleared by
00039      assigning 1 to them (and there's no way to set them); other bits
00040      are copied normally.  */
00041 
00042   cw &= ~((excepts << CAUSE_SHIFT) | FE_ALL_EXCEPT);
00043   cw |= excepts;
00044 
00045   /* Put the new data in effect.  */
00046   _FPU_SETFCW (cw);
00047 
00048   /* Success.  */
00049   return 0;
00050 }
00051 
00052 versioned_symbol (libm, __feclearexcept, feclearexcept, GLIBC_2_2);