mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-15 04:31:49 +08:00
85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/* This file is part of SIS (SPARC instruction simulator)
|
|
|
|
Copyright (C) 1995-2018 Free Software Foundation, Inc.
|
|
Contributed by Jiri Gaisler, European Space Agency
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
/* This file implements the interface between the host and the simulated
|
|
FPU. IEEE trap handling is done as follows:
|
|
1. In the host, all IEEE traps are masked
|
|
2. After each simulated FPU instruction, check if any exception
|
|
occured by reading the exception bits from the host FPU status
|
|
register (get_accex()).
|
|
3. Propagate any exceptions to the simulated FSR.
|
|
4. Clear host exception bits.
|
|
*/
|
|
|
|
#include "config.h"
|
|
#include "sis.h"
|
|
#include <fenv.h>
|
|
|
|
/* This routine should return the accrued exceptions */
|
|
int
|
|
get_accex()
|
|
{
|
|
int fexc, accx;
|
|
|
|
fexc = fetestexcept (FE_ALL_EXCEPT);
|
|
accx = 0;
|
|
if (fexc & FE_INEXACT)
|
|
accx |= 1;
|
|
if (fexc & FE_DIVBYZERO)
|
|
accx |= 2;
|
|
if (fexc & FE_UNDERFLOW)
|
|
accx |= 4;
|
|
if (fexc & FE_OVERFLOW)
|
|
accx |= 8;
|
|
if (fexc & FE_INVALID)
|
|
accx |= 0x10;
|
|
return accx;
|
|
}
|
|
|
|
/* How to clear the accrued exceptions */
|
|
void
|
|
clear_accex()
|
|
{
|
|
feclearexcept (FE_ALL_EXCEPT);
|
|
}
|
|
|
|
/* How to map SPARC FSR onto the host */
|
|
void
|
|
set_fsr(fsr)
|
|
uint32 fsr;
|
|
{
|
|
int fround;
|
|
|
|
fsr >>= 30;
|
|
switch (fsr) {
|
|
case 0:
|
|
fround = FE_TONEAREST;
|
|
break;
|
|
case 1:
|
|
fround = FE_TOWARDZERO;
|
|
break;
|
|
case 2:
|
|
fround = FE_UPWARD;
|
|
break;
|
|
case 3:
|
|
fround = FE_DOWNWARD;
|
|
break;
|
|
}
|
|
fesetround (fround);
|
|
}
|