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glibc  2.9
fesetround.c
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00001 /* Set current rounding direction.
00002    Copyright (C) 1999, 2000, 2005, 2007 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by Christian Boissat <Christian.Boissat@cern.ch>, 1999.
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 
00023 int
00024 fesetround (int round)
00025 {
00026   fenv_t fpsr;
00027 
00028   if (round & ~3)
00029     return 1;
00030 
00031   /* Get the current state.  */
00032   __asm__ __volatile__ ("mov.m %0=ar.fpsr" : "=r" (fpsr));
00033 
00034   /* Set the relevant bits.  */
00035   fpsr = (fpsr & ~(3UL << 10)) | ((fenv_t) round << 10);
00036 
00037   /* Put the new state in effect.  */
00038   __asm__ __volatile__ ("mov.m ar.fpsr=%0" :: "r" (fpsr) : "memory");
00039 
00040   return 0;
00041 }
00042 libm_hidden_def (fesetround)