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ARM: Implement flush to zero for destinations as well.

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This commit is contained in:
Gabe Black 2010-06-02 12:58:15 -05:00
parent 186273e5f3
commit fd82a47b96
2 changed files with 38 additions and 29 deletions
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12
src/arch/arm/insts/vfp.hh
View file

@ -175,16 +175,17 @@ bitsToFp(uint64_t bits, double junk)
template <class fpType>
static inline fpType
fixNan(FPSCR fpscr, fpType val, fpType op1, fpType op2)
fixDest(FPSCR fpscr, fpType val, fpType op1, fpType op2)
{
if (std::isnan(val)) {
int fpClass = std::fpclassify(val);
fpType junk = 0.0;
if (fpClass == FP_NAN) {
const bool single = (sizeof(val) == sizeof(float));
const uint64_t qnan = single ? 0x7fc00000 : ULL(0x7ff8000000000000);
const bool nan1 = std::isnan(op1);
const bool nan2 = std::isnan(op2);
const bool signal1 = nan1 && ((fpToBits(op1) & qnan) != qnan);
const bool signal2 = nan2 && ((fpToBits(op2) & qnan) != qnan);
fpType junk = 0.0;
if ((!nan1 && !nan2) || (fpscr.dn == 1)) {
val = bitsToFp(qnan, junk);
} else if (signal1) {
@ -196,6 +197,11 @@ fixNan(FPSCR fpscr, fpType val, fpType op1, fpType op2)
} else if (nan2) {
val = op2;
}
} else if (fpClass == FP_SUBNORMAL && fpscr.fz == 1) {
// Turn val into a zero with the correct sign;
uint64_t bitMask = ULL(0x1) << (sizeof(fpType) * 8 - 1);
val = bitsToFp(fpToBits(val) & bitMask, junk);
feraiseexcept(FeUnderflow);
}
return val;
}

55
src/arch/arm/isa/insts/fp.isa
View file

@ -386,7 +386,7 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
FpDest = fixNan(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
FpDest = fixDest(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
__asm__ __volatile__("" :: "m" (FpDest));
Fpscr = setVfpFpscr(Fpscr, state);
if ((isinf(FpOp1) && FpOp2 == 0) || (isinf(FpOp2) && FpOp1 == 0)) {
@ -407,7 +407,7 @@ let {{
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cOp1.fp));
cDest.fp = fixNan(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
cDest.fp = fixDest(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
__asm__ __volatile__("" :: "m" (cDest.fp));
Fpscr = setVfpFpscr(Fpscr, state);
if ((isinf(cOp1.fp) && cOp2.fp == 0) ||
@ -476,7 +476,7 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
FpDest = fixNan(Fpscr, FpOp1 + FpOp2, FpOp1, FpOp2);
FpDest = fixDest(Fpscr, FpOp1 + FpOp2, FpOp1, FpOp2);
__asm__ __volatile__("" :: "m" (FpDest));
Fpscr = setVfpFpscr(Fpscr, state);
'''
@ -491,10 +491,13 @@ let {{
IntDoubleUnion cOp1, cOp2, cDest;
cOp1.bits = ((uint64_t)FpOp1P0.uw | ((uint64_t)FpOp1P1.uw << 32));
cOp2.bits = ((uint64_t)FpOp2P0.uw | ((uint64_t)FpOp2P1.uw << 32));
DPRINTFN("cOp1.bits = %#x, cOp1.fp = %f.\\n", cOp1.bits, cOp1.fp);
DPRINTFN("cOp2.bits = %#x, cOp2.fp = %f.\\n", cOp2.bits, cOp2.fp);
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cOp1.fp));
cDest.fp = fixNan(Fpscr, cOp1.fp + cOp2.fp, cOp1.fp, cOp2.fp);
cDest.fp = fixDest(Fpscr, cOp1.fp + cOp2.fp, cOp1.fp, cOp2.fp);
DPRINTFN("cDest.bits = %#x, cDest.fp = %f.\\n", cDest.bits, cDest.fp);
__asm__ __volatile__("" :: "m" (cDest.fp));
Fpscr = setVfpFpscr(Fpscr, state);
FpDestP0.uw = cDest.bits;
@ -511,7 +514,7 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
FpDest = fixNan(Fpscr, FpOp1 - FpOp2, FpOp1, FpOp2);
FpDest = fixDest(Fpscr, FpOp1 - FpOp2, FpOp1, FpOp2);
__asm__ __volatile__("" :: "m" (FpDest));
Fpscr = setVfpFpscr(Fpscr, state)
'''
@ -529,7 +532,7 @@ let {{
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cOp1.fp));
cDest.fp = fixNan(Fpscr, cOp1.fp - cOp2.fp, cOp1.fp, cOp2.fp);
cDest.fp = fixDest(Fpscr, cOp1.fp - cOp2.fp, cOp1.fp, cOp2.fp);
__asm__ __volatile__("" :: "m" (cDest.fp));
Fpscr = setVfpFpscr(Fpscr, state);
FpDestP0.uw = cDest.bits;
@ -546,7 +549,7 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
FpDest = fixNan(Fpscr, FpOp1 / FpOp2, FpOp1, FpOp2);
FpDest = fixDest(Fpscr, FpOp1 / FpOp2, FpOp1, FpOp2);
__asm__ __volatile__("" :: "m" (FpDest));
Fpscr = setVfpFpscr(Fpscr, state);
'''
@ -564,7 +567,7 @@ let {{
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cDest.fp));
cDest.fp = fixNan(Fpscr, cOp1.fp / cOp2.fp, cOp1.fp, cOp2.fp);
cDest.fp = fixDest(Fpscr, cOp1.fp / cOp2.fp, cOp1.fp, cOp2.fp);
__asm__ __volatile__("" :: "m" (cDest.fp));
Fpscr = setVfpFpscr(Fpscr, state);
FpDestP0.uw = cDest.bits;
@ -628,12 +631,12 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
float mid = fixNan(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
float mid = fixDest(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
if ((isinf(FpOp1) && FpOp2 == 0) || (isinf(FpOp2) && FpOp1 == 0)) {
mid = NAN;
}
vfpFlushToZero(Fpscr, FpDest, mid);
FpDest = fixNan(Fpscr, FpDest + mid, FpDest, mid);
FpDest = fixDest(Fpscr, FpDest + mid, FpDest, mid);
__asm__ __volatile__("" :: "m" (FpDest));
Fpscr = setVfpFpscr(Fpscr, state);
'''
@ -652,13 +655,13 @@ let {{
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cOp1.fp));
double mid = fixNan(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
double mid = fixDest(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
if ((isinf(cOp1.fp) && cOp2.fp == 0) ||
(isinf(cOp2.fp) && cOp1.fp == 0)) {
mid = NAN;
}
vfpFlushToZero(Fpscr, cDest.fp, mid);
cDest.fp = fixNan(Fpscr, cDest.fp + mid, cDest.fp, mid);
cDest.fp = fixDest(Fpscr, cDest.fp + mid, cDest.fp, mid);
__asm__ __volatile__("" :: "m" (cDest.fp));
Fpscr = setVfpFpscr(Fpscr, state);
FpDestP0.uw = cDest.bits;
@ -675,12 +678,12 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
float mid = fixNan(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
float mid = fixDest(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
if ((isinf(FpOp1) && FpOp2 == 0) || (isinf(FpOp2) && FpOp1 == 0)) {
mid = NAN;
}
vfpFlushToZero(Fpscr, FpDest, mid);
FpDest = fixNan(Fpscr, FpDest - mid, FpDest, mid);
FpDest = fixDest(Fpscr, FpDest - mid, FpDest, mid);
__asm__ __volatile__("" :: "m" (FpDest));
Fpscr = setVfpFpscr(Fpscr, state);
'''
@ -699,12 +702,12 @@ let {{
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cOp1.fp));
double mid = fixNan(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
double mid = fixDest(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
if ((isinf(cOp1.fp) && cOp2.fp == 0) ||
(isinf(cOp2.fp) && cOp1.fp == 0)) {
mid = NAN;
}
cDest.fp = fixNan(Fpscr, cDest.fp - mid, cDest.fp, mid);
cDest.fp = fixDest(Fpscr, cDest.fp - mid, cDest.fp, mid);
vfpFlushToZero(Fpscr, cDest.fp, mid);
__asm__ __volatile__("" :: "m" (cDest.fp));
Fpscr = setVfpFpscr(Fpscr, state);
@ -722,12 +725,12 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
float mid = fixNan(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
float mid = fixDest(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
if ((isinf(FpOp1) && FpOp2 == 0) || (isinf(FpOp2) && FpOp1 == 0)) {
mid = NAN;
}
vfpFlushToZero(Fpscr, FpDest, mid);
FpDest = fixNan(Fpscr, -FpDest - mid, FpDest, mid);
FpDest = fixDest(Fpscr, -FpDest - mid, FpDest, mid);
__asm__ __volatile__("" :: "m" (FpDest));
Fpscr = setVfpFpscr(Fpscr, state);
'''
@ -746,13 +749,13 @@ let {{
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cOp1.fp));
double mid = fixNan(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
double mid = fixDest(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
if ((isinf(cOp1.fp) && cOp2.fp == 0) ||
(isinf(cOp2.fp) && cOp1.fp == 0)) {
mid = NAN;
}
vfpFlushToZero(Fpscr, cDest.fp, mid);
cDest.fp = fixNan(Fpscr, -cDest.fp - mid, cDest.fp, mid);
cDest.fp = fixDest(Fpscr, -cDest.fp - mid, cDest.fp, mid);
__asm__ __volatile__("" :: "m" (cDest.fp));
Fpscr = setVfpFpscr(Fpscr, state);
FpDestP0.uw = cDest.bits;
@ -769,12 +772,12 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
float mid = fixNan(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
float mid = fixDest(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
if ((isinf(FpOp1) && FpOp2 == 0) || (isinf(FpOp2) && FpOp1 == 0)) {
mid = NAN;
}
vfpFlushToZero(Fpscr, FpDest, mid);
FpDest = fixNan(Fpscr, -FpDest + mid, FpDest, mid);
FpDest = fixDest(Fpscr, -FpDest + mid, FpDest, mid);
__asm__ __volatile__("" :: "m" (FpDest));
Fpscr = setVfpFpscr(Fpscr, state);
'''
@ -793,13 +796,13 @@ let {{
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cOp1.fp));
double mid = fixNan(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
double mid = fixDest(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
if ((isinf(cOp1.fp) && cOp2.fp == 0) ||
(isinf(cOp2.fp) && cOp1.fp == 0)) {
mid = NAN;
}
vfpFlushToZero(Fpscr, cDest.fp, mid);
cDest.fp = fixNan(Fpscr, -cDest.fp + mid, cDest.fp, mid);
cDest.fp = fixDest(Fpscr, -cDest.fp + mid, cDest.fp, mid);
__asm__ __volatile__("" :: "m" (cDest.fp));
Fpscr = setVfpFpscr(Fpscr, state);
FpDestP0.uw = cDest.bits;
@ -816,7 +819,7 @@ let {{
vfpFlushToZero(Fpscr, FpOp1, FpOp2);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (FpOp1) : "m" (FpOp1));
float mid = fixNan(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
float mid = fixDest(Fpscr, FpOp1 * FpOp2, FpOp1, FpOp2);
if ((isinf(FpOp1) && FpOp2 == 0) || (isinf(FpOp2) && FpOp1 == 0)) {
mid = NAN;
}
@ -839,7 +842,7 @@ let {{
vfpFlushToZero(Fpscr, cOp1.fp, cOp2.fp);
VfpSavedState state = prepVfpFpscr(Fpscr);
__asm__ __volatile__("" : "=m" (cOp1.fp) : "m" (cOp1.fp));
double mid = fixNan(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
double mid = fixDest(Fpscr, cOp1.fp * cOp2.fp, cOp1.fp, cOp2.fp);
if ((isinf(cOp1.fp) && cOp2.fp == 0) ||
(isinf(cOp2.fp) && cOp1.fp == 0)) {
mid = NAN;