linux-stable/arch/arm/nwfpe/double_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

167 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"
union float64_components {
float64 f64;
unsigned int i[2];
};
float64 float64_exp(float64 Fm);
float64 float64_ln(float64 Fm);
float64 float64_sin(float64 rFm);
float64 float64_cos(float64 rFm);
float64 float64_arcsin(float64 rFm);
float64 float64_arctan(float64 rFm);
float64 float64_log(float64 rFm);
float64 float64_tan(float64 rFm);
float64 float64_arccos(float64 rFm);
float64 float64_pow(float64 rFn, float64 rFm);
float64 float64_pol(float64 rFn, float64 rFm);
static float64 float64_rsf(struct roundingData *roundData, float64 rFn, float64 rFm)
{
return float64_sub(roundData, rFm, rFn);
}
static float64 float64_rdv(struct roundingData *roundData, float64 rFn, float64 rFm)
{
return float64_div(roundData, rFm, rFn);
}
static float64 (*const dyadic_double[16])(struct roundingData*, float64 rFn, float64 rFm) = {
[ADF_CODE >> 20] = float64_add,
[MUF_CODE >> 20] = float64_mul,
[SUF_CODE >> 20] = float64_sub,
[RSF_CODE >> 20] = float64_rsf,
[DVF_CODE >> 20] = float64_div,
[RDF_CODE >> 20] = float64_rdv,
[RMF_CODE >> 20] = float64_rem,
/* strictly, these opcodes should not be implemented */
[FML_CODE >> 20] = float64_mul,
[FDV_CODE >> 20] = float64_div,
[FRD_CODE >> 20] = float64_rdv,
};
static float64 float64_mvf(struct roundingData *roundData,float64 rFm)
{
return rFm;
}
static float64 float64_mnf(struct roundingData *roundData,float64 rFm)
{
union float64_components u;
u.f64 = rFm;
#ifdef __ARMEB__
u.i[0] ^= 0x80000000;
#else
u.i[1] ^= 0x80000000;
#endif
return u.f64;
}
static float64 float64_abs(struct roundingData *roundData,float64 rFm)
{
union float64_components u;
u.f64 = rFm;
#ifdef __ARMEB__
u.i[0] &= 0x7fffffff;
#else
u.i[1] &= 0x7fffffff;
#endif
return u.f64;
}
static float64 (*const monadic_double[16])(struct roundingData *, float64 rFm) = {
[MVF_CODE >> 20] = float64_mvf,
[MNF_CODE >> 20] = float64_mnf,
[ABS_CODE >> 20] = float64_abs,
[RND_CODE >> 20] = float64_round_to_int,
[URD_CODE >> 20] = float64_round_to_int,
[SQT_CODE >> 20] = float64_sqrt,
[NRM_CODE >> 20] = float64_mvf,
};
unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd)
{
FPA11 *fpa11 = GET_FPA11();
float64 rFm;
unsigned int Fm, opc_mask_shift;
Fm = getFm(opcode);
if (CONSTANT_FM(opcode)) {
rFm = getDoubleConstant(Fm);
} else {
switch (fpa11->fType[Fm]) {
case typeSingle:
rFm = float32_to_float64(fpa11->fpreg[Fm].fSingle);
break;
case typeDouble:
rFm = fpa11->fpreg[Fm].fDouble;
break;
default:
return 0;
}
}
opc_mask_shift = (opcode & MASK_ARITHMETIC_OPCODE) >> 20;
if (!MONADIC_INSTRUCTION(opcode)) {
unsigned int Fn = getFn(opcode);
float64 rFn;
switch (fpa11->fType[Fn]) {
case typeSingle:
rFn = float32_to_float64(fpa11->fpreg[Fn].fSingle);
break;
case typeDouble:
rFn = fpa11->fpreg[Fn].fDouble;
break;
default:
return 0;
}
if (dyadic_double[opc_mask_shift]) {
rFd->fDouble = dyadic_double[opc_mask_shift](roundData, rFn, rFm);
} else {
return 0;
}
} else {
if (monadic_double[opc_mask_shift]) {
rFd->fDouble = monadic_double[opc_mask_shift](roundData, rFm);
} else {
return 0;
}
}
return 1;
}