assert(V != 0 && "Null pointer of Value???");
assert(Depth <= 6 && "Limit Search Depth");
uint32_t BitWidth = DemandedMask.getBitWidth();
- const Type *VTy = V->getType();
+ Type *VTy = V->getType();
assert((TD || !VTy->isPointerTy()) &&
"SimplifyDemandedBits needs to know bit widths!");
assert((!TD || TD->getTypeSizeInBits(VTy->getScalarType()) == BitWidth) &&
Instruction *I = dyn_cast<Instruction>(V);
if (!I) {
- ComputeMaskedBits(V, DemandedMask, KnownZero, KnownOne, Depth);
+ ComputeMaskedBits(V, KnownZero, KnownOne, Depth);
return 0; // Only analyze instructions.
}
// this instruction has a simpler value in that context.
if (I->getOpcode() == Instruction::And) {
// If either the LHS or the RHS are Zero, the result is zero.
- ComputeMaskedBits(I->getOperand(1), DemandedMask,
- RHSKnownZero, RHSKnownOne, Depth+1);
- ComputeMaskedBits(I->getOperand(0), DemandedMask & ~RHSKnownZero,
- LHSKnownZero, LHSKnownOne, Depth+1);
+ ComputeMaskedBits(I->getOperand(1), RHSKnownZero, RHSKnownOne, Depth+1);
+ ComputeMaskedBits(I->getOperand(0), LHSKnownZero, LHSKnownOne, Depth+1);
// If all of the demanded bits are known 1 on one side, return the other.
// These bits cannot contribute to the result of the 'and' in this
// only bits from X or Y are demanded.
// If either the LHS or the RHS are One, the result is One.
- ComputeMaskedBits(I->getOperand(1), DemandedMask,
- RHSKnownZero, RHSKnownOne, Depth+1);
- ComputeMaskedBits(I->getOperand(0), DemandedMask & ~RHSKnownOne,
- LHSKnownZero, LHSKnownOne, Depth+1);
+ ComputeMaskedBits(I->getOperand(1), RHSKnownZero, RHSKnownOne, Depth+1);
+ ComputeMaskedBits(I->getOperand(0), LHSKnownZero, LHSKnownOne, Depth+1);
// If all of the demanded bits are known zero on one side, return the
// other. These bits cannot contribute to the result of the 'or' in this
}
// Compute the KnownZero/KnownOne bits to simplify things downstream.
- ComputeMaskedBits(I, DemandedMask, KnownZero, KnownOne, Depth);
+ ComputeMaskedBits(I, KnownZero, KnownOne, Depth);
return 0;
}
switch (I->getOpcode()) {
default:
- ComputeMaskedBits(I, DemandedMask, KnownZero, KnownOne, Depth);
+ ComputeMaskedBits(I, KnownZero, KnownOne, Depth);
break;
case Instruction::And:
// If either the LHS or the RHS are Zero, the result is zero.
if ((RHSKnownOne & LHSKnownOne) == RHSKnownOne) {
Constant *AndC = Constant::getIntegerValue(VTy,
~RHSKnownOne & DemandedMask);
- Instruction *And =
- BinaryOperator::CreateAnd(I->getOperand(0), AndC, "tmp");
+ Instruction *And = BinaryOperator::CreateAnd(I->getOperand(0), AndC);
return InsertNewInstWith(And, *I);
}
}
Constant *AndC =
ConstantInt::get(I->getType(), NewMask & AndRHS->getValue());
- Instruction *NewAnd =
- BinaryOperator::CreateAnd(I->getOperand(0), AndC, "tmp");
+ Instruction *NewAnd = BinaryOperator::CreateAnd(I->getOperand(0), AndC);
InsertNewInstWith(NewAnd, *I);
Constant *XorC =
ConstantInt::get(I->getType(), NewMask & XorRHS->getValue());
- Instruction *NewXor =
- BinaryOperator::CreateXor(NewAnd, XorC, "tmp");
+ Instruction *NewXor = BinaryOperator::CreateXor(NewAnd, XorC);
return InsertNewInstWith(NewXor, *I);
}
if (!I->getOperand(0)->getType()->isIntOrIntVectorTy())
return 0; // vector->int or fp->int?
- if (const VectorType *DstVTy = dyn_cast<VectorType>(I->getType())) {
- if (const VectorType *SrcVTy =
+ if (VectorType *DstVTy = dyn_cast<VectorType>(I->getType())) {
+ if (VectorType *SrcVTy =
dyn_cast<VectorType>(I->getOperand(0)->getType())) {
if (DstVTy->getNumElements() != SrcVTy->getNumElements())
// Don't touch a bitcast between vectors of different element counts.
LHSKnownZero, LHSKnownOne, Depth+1))
return I;
}
+
// Otherwise just hand the sub off to ComputeMaskedBits to fill in
// the known zeros and ones.
- ComputeMaskedBits(V, DemandedMask, KnownZero, KnownOne, Depth);
+ ComputeMaskedBits(V, KnownZero, KnownOne, Depth);
+
+ // Turn this into a xor if LHS is 2^n-1 and the remaining bits are known
+ // zero.
+ if (ConstantInt *C0 = dyn_cast<ConstantInt>(I->getOperand(0))) {
+ APInt I0 = C0->getValue();
+ if ((I0 + 1).isPowerOf2() && (I0 | KnownZero).isAllOnesValue()) {
+ Instruction *Xor = BinaryOperator::CreateXor(I->getOperand(1), C0);
+ return InsertNewInstWith(Xor, *I);
+ }
+ }
break;
case Instruction::Shl:
if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
if (BitWidth <= ShiftAmt || KnownZero[BitWidth-ShiftAmt-1] ||
(HighBits & ~DemandedMask) == HighBits) {
// Perform the logical shift right.
- Instruction *NewVal = BinaryOperator::CreateLShr(
- I->getOperand(0), SA, I->getName());
+ BinaryOperator *NewVal = BinaryOperator::CreateLShr(I->getOperand(0),
+ SA, I->getName());
+ NewVal->setIsExact(cast<BinaryOperator>(I)->isExact());
return InsertNewInstWith(NewVal, *I);
} else if ((KnownOne & SignBit) != 0) { // New bits are known one.
KnownOne |= HighBits;
// The sign bit is the LHS's sign bit, except when the result of the
// remainder is zero.
if (DemandedMask.isNegative() && KnownZero.isNonNegative()) {
- APInt Mask2 = APInt::getSignBit(BitWidth);
APInt LHSKnownZero(BitWidth, 0), LHSKnownOne(BitWidth, 0);
- ComputeMaskedBits(I->getOperand(0), Mask2, LHSKnownZero, LHSKnownOne,
- Depth+1);
+ ComputeMaskedBits(I->getOperand(0), LHSKnownZero, LHSKnownOne, Depth+1);
// If it's known zero, our sign bit is also zero.
if (LHSKnownZero.isNegative())
KnownZero |= LHSKnownZero;
return 0;
}
}
- ComputeMaskedBits(V, DemandedMask, KnownZero, KnownOne, Depth);
+ ComputeMaskedBits(V, KnownZero, KnownOne, Depth);
break;
}
}
UndefElts = 0;
- if (ConstantVector *CV = dyn_cast<ConstantVector>(V)) {
- const Type *EltTy = cast<VectorType>(V->getType())->getElementType();
- Constant *Undef = UndefValue::get(EltTy);
+
+ // Handle ConstantAggregateZero, ConstantVector, ConstantDataSequential.
+ if (Constant *C = dyn_cast<Constant>(V)) {
+ // Check if this is identity. If so, return 0 since we are not simplifying
+ // anything.
+ if (DemandedElts.isAllOnesValue())
+ return 0;
- std::vector<Constant*> Elts;
- for (unsigned i = 0; i != VWidth; ++i)
+ Type *EltTy = cast<VectorType>(V->getType())->getElementType();
+ Constant *Undef = UndefValue::get(EltTy);
+
+ SmallVector<Constant*, 16> Elts;
+ for (unsigned i = 0; i != VWidth; ++i) {
if (!DemandedElts[i]) { // If not demanded, set to undef.
Elts.push_back(Undef);
UndefElts.setBit(i);
- } else if (isa<UndefValue>(CV->getOperand(i))) { // Already undef.
+ continue;
+ }
+
+ Constant *Elt = C->getAggregateElement(i);
+ if (Elt == 0) return 0;
+
+ if (isa<UndefValue>(Elt)) { // Already undef.
Elts.push_back(Undef);
UndefElts.setBit(i);
} else { // Otherwise, defined.
- Elts.push_back(CV->getOperand(i));
+ Elts.push_back(Elt);
}
-
- // If we changed the constant, return it.
- Constant *NewCP = ConstantVector::get(Elts);
- return NewCP != CV ? NewCP : 0;
- }
-
- if (isa<ConstantAggregateZero>(V)) {
- // Simplify the CAZ to a ConstantVector where the non-demanded elements are
- // set to undef.
-
- // Check if this is identity. If so, return 0 since we are not simplifying
- // anything.
- if (DemandedElts.isAllOnesValue())
- return 0;
-
- const Type *EltTy = cast<VectorType>(V->getType())->getElementType();
- Constant *Zero = Constant::getNullValue(EltTy);
- Constant *Undef = UndefValue::get(EltTy);
- std::vector<Constant*> Elts;
- for (unsigned i = 0; i != VWidth; ++i) {
- Constant *Elt = DemandedElts[i] ? Zero : Undef;
- Elts.push_back(Elt);
}
- UndefElts = DemandedElts ^ EltMask;
- return ConstantVector::get(Elts);
+
+ // If we changed the constant, return it.
+ Constant *NewCV = ConstantVector::get(Elts);
+ return NewCV != C ? NewCV : 0;
}
// Limit search depth.
unsigned MaskVal = Shuffle->getMaskValue(i);
if (MaskVal == -1u) {
UndefElts.setBit(i);
+ } else if (!DemandedElts[i]) {
+ NewUndefElts = true;
+ UndefElts.setBit(i);
} else if (MaskVal < LHSVWidth) {
if (UndefElts4[MaskVal]) {
NewUndefElts = true;
if (NewUndefElts) {
// Add additional discovered undefs.
- std::vector<Constant*> Elts;
+ SmallVector<Constant*, 16> Elts;
for (unsigned i = 0; i < VWidth; ++i) {
if (UndefElts[i])
Elts.push_back(UndefValue::get(Type::getInt32Ty(I->getContext())));
}
case Instruction::BitCast: {
// Vector->vector casts only.
- const VectorType *VTy = dyn_cast<VectorType>(I->getOperand(0)->getType());
+ VectorType *VTy = dyn_cast<VectorType>(I->getOperand(0)->getType());
if (!VTy) break;
unsigned InVWidth = VTy->getNumElements();
APInt InputDemandedElts(InVWidth, 0);
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