glibc/sysdeps/alpha/fpu/fesetround.c

43 lines
1.3 KiB
C

/* Set current rounding direction.
Copyright (C) 1997-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson <rth@tamu.edu>, 1997
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
#include <fenv_libc.h>
int
fesetround (int round)
{
unsigned long fpcr;
if (round & ~3)
return 1;
/* Get the current state. */
__asm__ __volatile__("excb; mf_fpcr %0" : "=f"(fpcr));
/* Set the relevant bits. */
fpcr = ((fpcr & ~FPCR_ROUND_MASK)
| ((unsigned long)round << FPCR_ROUND_SHIFT));
/* Put the new state in effect. */
__asm__ __volatile__("mt_fpcr %0; excb" : : "f"(fpcr));
return 0;
}
libm_hidden_def (fesetround)