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2002-05-28 Roland McGrath <roland@frob.com>

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* sysdeps/mach/alpha/setfpucw.c: New file.
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Roland McGrath 2002-05-29 08:09:20 +00:00
parent eb7e1f616e
commit 2b2c911513
1 changed files with 69 additions and 0 deletions
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sysdeps/mach/alpha/setfpucw.c Normal file
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/* Set FP exception mask and rounding mode. Mach/Alpha version.
Copyright (C) 2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <fpu_control.h>
#define FPCR_DYN_SHIFT 58 /* first dynamic rounding mode bit */
#define FPCR_DYN_CHOPPED (0x0UL << FPCR_DYN_SHIFT) /* towards 0 */
#define FPCR_DYN_MINUS (0x1UL << FPCR_DYN_SHIFT) /* towards -INF */
#define FPCR_DYN_NORMAL (0x2UL << FPCR_DYN_SHIFT) /* towards nearest */
#define FPCR_DYN_PLUS (0x3UL << FPCR_DYN_SHIFT) /* towards +INF */
#define FPCR_DYN_MASK (0x3UL << FPCR_DYN_SHIFT)
static inline unsigned long
rdfpcr (void)
{
unsigned long fpcr;
asm ("excb; mf_fpcr %0" : "=f"(fpcr));
return fpcr;
}
static inline void
wrfpcr (unsigned long fpcr)
{
asm volatile ("mt_fpcr %0; excb" : : "f"(fpcr));
}
void
__setfpucw (fpu_control_t fpu_control)
{
unsigned long fpcr;
if (!fpu_control)
fpu_control = _FPU_DEFAULT;
/* first, set dynamic rounding mode: */
fpcr = rdfpcr();
fpcr &= ~FPCR_DYN_MASK;
switch (fpu_control & 0xc00)
{
case _FPU_RC_NEAREST: fpcr |= FPCR_DYN_NORMAL; break;
case _FPU_RC_DOWN: fpcr |= FPCR_DYN_MINUS; break;
case _FPU_RC_UP: fpcr |= FPCR_DYN_PLUS; break;
case _FPU_RC_ZERO: fpcr |= FPCR_DYN_CHOPPED; break;
}
wrfpcr(fpcr);
/* XXX trap bits? */
__fpu_control = fpu_control; /* update global copy */
}