linux-hardened/arch/arm/nwfpe/extended_cpdo.c
Richard Purdie f148af2593 [PATCH] ARM: 2837/2: Re: ARM: Make NWFPE preempt safe
Patch from Richard Purdie

NWFPE used global variables which meant it wasn't safe for use with
preemptive kernels. This patch removes them and communicates the
information between functions in a preempt safe manner. Generation
of some exceptions was broken and this has also been corrected.
Tests with glibc's maths test suite show no change in the results
before/after this patch.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-08-03 19:49:17 +01:00

154 lines
4 KiB
C

/*
NetWinder Floating Point Emulator
(c) Rebel.COM, 1998,1999
Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "fpa11.h"
#include "softfloat.h"
#include "fpopcode.h"
floatx80 floatx80_exp(floatx80 Fm);
floatx80 floatx80_ln(floatx80 Fm);
floatx80 floatx80_sin(floatx80 rFm);
floatx80 floatx80_cos(floatx80 rFm);
floatx80 floatx80_arcsin(floatx80 rFm);
floatx80 floatx80_arctan(floatx80 rFm);
floatx80 floatx80_log(floatx80 rFm);
floatx80 floatx80_tan(floatx80 rFm);
floatx80 floatx80_arccos(floatx80 rFm);
floatx80 floatx80_pow(floatx80 rFn, floatx80 rFm);
floatx80 floatx80_pol(floatx80 rFn, floatx80 rFm);
static floatx80 floatx80_rsf(struct roundingData *roundData, floatx80 rFn, floatx80 rFm)
{
return floatx80_sub(roundData, rFm, rFn);
}
static floatx80 floatx80_rdv(struct roundingData *roundData, floatx80 rFn, floatx80 rFm)
{
return floatx80_div(roundData, rFm, rFn);
}
static floatx80 (*const dyadic_extended[16])(struct roundingData*, floatx80 rFn, floatx80 rFm) = {
[ADF_CODE >> 20] = floatx80_add,
[MUF_CODE >> 20] = floatx80_mul,
[SUF_CODE >> 20] = floatx80_sub,
[RSF_CODE >> 20] = floatx80_rsf,
[DVF_CODE >> 20] = floatx80_div,
[RDF_CODE >> 20] = floatx80_rdv,
[RMF_CODE >> 20] = floatx80_rem,
/* strictly, these opcodes should not be implemented */
[FML_CODE >> 20] = floatx80_mul,
[FDV_CODE >> 20] = floatx80_div,
[FRD_CODE >> 20] = floatx80_rdv,
};
static floatx80 floatx80_mvf(struct roundingData *roundData, floatx80 rFm)
{
return rFm;
}
static floatx80 floatx80_mnf(struct roundingData *roundData, floatx80 rFm)
{
rFm.high ^= 0x8000;
return rFm;
}
static floatx80 floatx80_abs(struct roundingData *roundData, floatx80 rFm)
{
rFm.high &= 0x7fff;
return rFm;
}
static floatx80 (*const monadic_extended[16])(struct roundingData*, floatx80 rFm) = {
[MVF_CODE >> 20] = floatx80_mvf,
[MNF_CODE >> 20] = floatx80_mnf,
[ABS_CODE >> 20] = floatx80_abs,
[RND_CODE >> 20] = floatx80_round_to_int,
[URD_CODE >> 20] = floatx80_round_to_int,
[SQT_CODE >> 20] = floatx80_sqrt,
[NRM_CODE >> 20] = floatx80_mvf,
};
unsigned int ExtendedCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd)
{
FPA11 *fpa11 = GET_FPA11();
floatx80 rFm;
unsigned int Fm, opc_mask_shift;
Fm = getFm(opcode);
if (CONSTANT_FM(opcode)) {
rFm = getExtendedConstant(Fm);
} else {
switch (fpa11->fType[Fm]) {
case typeSingle:
rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle);
break;
case typeDouble:
rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble);
break;
case typeExtended:
rFm = fpa11->fpreg[Fm].fExtended;
break;
default:
return 0;
}
}
opc_mask_shift = (opcode & MASK_ARITHMETIC_OPCODE) >> 20;
if (!MONADIC_INSTRUCTION(opcode)) {
unsigned int Fn = getFn(opcode);
floatx80 rFn;
switch (fpa11->fType[Fn]) {
case typeSingle:
rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle);
break;
case typeDouble:
rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble);
break;
case typeExtended:
rFn = fpa11->fpreg[Fn].fExtended;
break;
default:
return 0;
}
if (dyadic_extended[opc_mask_shift]) {
rFd->fExtended = dyadic_extended[opc_mask_shift](roundData, rFn, rFm);
} else {
return 0;
}
} else {
if (monadic_extended[opc_mask_shift]) {
rFd->fExtended = monadic_extended[opc_mask_shift](roundData, rFm);
} else {
return 0;
}
}
return 1;
}