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.
// 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.
// 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)) {
+
+ // 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;
+
Type *EltTy = cast<VectorType>(V->getType())->getElementType();
Constant *Undef = UndefValue::get(EltTy);
-
- std::vector<Constant*> Elts;
- for (unsigned i = 0; i != VWidth; ++i)
+
+ 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 *NewCV = ConstantVector::get(Elts);
- return NewCV != CV ? NewCV : 0;
- }
-
- if (ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(V)) {
- // Check if this is identity. If so, return 0 since we are not simplifying
- // anything.
- if (DemandedElts.isAllOnesValue())
- return 0;
-
- // Simplify to a ConstantVector where the non-demanded elements are undef.
- Constant *Undef = UndefValue::get(CDV->getElementType());
-
- SmallVector<Constant*, 16> Elts;
- for (unsigned i = 0; i != VWidth; ++i)
- Elts.push_back(DemandedElts[i] ? CDV->getElementAsConstant(i) : Undef);
- UndefElts = DemandedElts ^ EltMask;
- return ConstantVector::get(Elts);
-
- }
-
- if (ConstantAggregateZero *CAZ = dyn_cast<ConstantAggregateZero>(V)) {
- // Check if this is identity. If so, return 0 since we are not simplifying
- // anything.
- if (DemandedElts.isAllOnesValue())
- return 0;
-
- // Simplify the CAZ to a ConstantVector where the non-demanded elements are
- // set to undef.
- Constant *Zero = CAZ->getSequentialElement();
- Constant *Undef = UndefValue::get(Zero->getType());
- SmallVector<Constant*, 16> Elts;
- for (unsigned i = 0; i != VWidth; ++i)
- Elts.push_back(DemandedElts[i] ? Zero : Undef);
- UndefElts = DemandedElts ^ EltMask;
- return ConstantVector::get(Elts);
+ return NewCV != C ? NewCV : 0;
}
// Limit search depth.
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())));