summaryrefslogtreecommitdiffstats
path: root/lib/Transforms
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Transforms')
-rw-r--r--lib/Transforms/Scalar/InstructionCombining.cpp48
1 files changed, 24 insertions, 24 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 461b0a0..ac502ce 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -578,7 +578,7 @@ static ConstantInt *SubOne(ConstantInt *C) {
/// optimized based on the contradictory assumption that it is non-zero.
/// Because instcombine aggressively folds operations with undef args anyway,
/// this won't lose us code quality.
-static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
+static void ComputeMaskedBits(Value *V, const APInt& Mask, APInt& KnownZero,
APInt& KnownOne, unsigned Depth = 0) {
assert(V && "No Value?");
assert(Depth <= 6 && "Limit Search Depth");
@@ -603,14 +603,13 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
KnownZero.clear(); KnownOne.clear(); // Don't know anything.
APInt KnownZero2(KnownZero), KnownOne2(KnownOne);
- Mask &= APInt::getAllOnesValue(BitWidth);
switch (I->getOpcode()) {
- case Instruction::And:
+ case Instruction::And: {
// If either the LHS or the RHS are Zero, the result is zero.
ComputeMaskedBits(I->getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
- Mask &= ~KnownZero;
- ComputeMaskedBits(I->getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
+ APInt Mask2(Mask & ~KnownZero);
+ ComputeMaskedBits(I->getOperand(0), Mask2, KnownZero2, KnownOne2, Depth+1);
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
@@ -619,10 +618,11 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
// Output known-0 are known to be clear if zero in either the LHS | RHS.
KnownZero |= KnownZero2;
return;
- case Instruction::Or:
+ }
+ case Instruction::Or: {
ComputeMaskedBits(I->getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
- Mask &= ~KnownOne;
- ComputeMaskedBits(I->getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
+ APInt Mask2(Mask & ~KnownOne);
+ ComputeMaskedBits(I->getOperand(0), Mask2, KnownZero2, KnownOne2, Depth+1);
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
@@ -631,6 +631,7 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
// Output known-1 are known to be set if set in either the LHS | RHS.
KnownOne |= KnownOne2;
return;
+ }
case Instruction::Xor: {
ComputeMaskedBits(I->getOperand(1), Mask, KnownZero, KnownOne, Depth+1);
ComputeMaskedBits(I->getOperand(0), Mask, KnownZero2, KnownOne2, Depth+1);
@@ -667,7 +668,7 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
// All these have integer operands
uint32_t SrcBitWidth =
cast<IntegerType>(I->getOperand(0)->getType())->getBitWidth();
- ComputeMaskedBits(I->getOperand(0), Mask.zext(SrcBitWidth),
+ ComputeMaskedBits(I->getOperand(0), APInt(Mask).zext(SrcBitWidth),
KnownZero.zext(SrcBitWidth), KnownOne.zext(SrcBitWidth), Depth+1);
KnownZero.trunc(BitWidth);
KnownOne.trunc(BitWidth);
@@ -687,7 +688,7 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
APInt NewBits(APInt::getAllOnesValue(BitWidth).shl(SrcTy->getBitWidth()));
uint32_t SrcBitWidth = SrcTy->getBitWidth();
- ComputeMaskedBits(I->getOperand(0), Mask.trunc(SrcBitWidth),
+ ComputeMaskedBits(I->getOperand(0), APInt(Mask).trunc(SrcBitWidth),
KnownZero.trunc(SrcBitWidth), KnownOne.trunc(SrcBitWidth), Depth+1);
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
// The top bits are known to be zero.
@@ -702,7 +703,7 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
APInt NewBits(APInt::getAllOnesValue(BitWidth).shl(SrcTy->getBitWidth()));
uint32_t SrcBitWidth = SrcTy->getBitWidth();
- ComputeMaskedBits(I->getOperand(0), Mask.trunc(SrcBitWidth),
+ ComputeMaskedBits(I->getOperand(0), APInt(Mask).trunc(SrcBitWidth),
KnownZero.trunc(SrcBitWidth), KnownOne.trunc(SrcBitWidth), Depth+1);
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero.zext(BitWidth);
@@ -728,8 +729,8 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
// (shl X, C1) & C2 == 0 iff (X & C2 >>u C1) == 0
if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
uint64_t ShiftAmt = SA->getZExtValue();
- Mask = APIntOps::lshr(Mask, ShiftAmt);
- ComputeMaskedBits(I->getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
+ APInt Mask2(Mask.lshr(ShiftAmt));
+ ComputeMaskedBits(I->getOperand(0), Mask2, KnownZero, KnownOne, Depth+1);
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
KnownZero <<= ShiftAmt;
KnownOne <<= ShiftAmt;
@@ -745,8 +746,8 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
APInt HighBits(APInt::getAllOnesValue(BitWidth).shl(BitWidth-ShiftAmt));
// Unsigned shift right.
- Mask <<= ShiftAmt;
- ComputeMaskedBits(I->getOperand(0), Mask, KnownZero,KnownOne,Depth+1);
+ APInt Mask2(Mask.shl(ShiftAmt));
+ ComputeMaskedBits(I->getOperand(0), Mask2, KnownZero,KnownOne,Depth+1);
assert((KnownZero & KnownOne) == 0&&"Bits known to be one AND zero?");
KnownZero = APIntOps::lshr(KnownZero, ShiftAmt);
KnownOne = APIntOps::lshr(KnownOne, ShiftAmt);
@@ -762,8 +763,8 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero,
APInt HighBits(APInt::getAllOnesValue(BitWidth).shl(BitWidth-ShiftAmt));
// Signed shift right.
- Mask <<= ShiftAmt;
- ComputeMaskedBits(I->getOperand(0), Mask, KnownZero,KnownOne,Depth+1);
+ APInt Mask2(Mask.shl(ShiftAmt));
+ ComputeMaskedBits(I->getOperand(0), Mask2, KnownZero,KnownOne,Depth+1);
assert((KnownZero & KnownOne) == 0&&"Bits known to be one AND zero?");
KnownZero = APIntOps::lshr(KnownZero, ShiftAmt);
KnownOne = APIntOps::lshr(KnownOne, ShiftAmt);
@@ -924,8 +925,6 @@ bool InstCombiner::SimplifyDemandedBits(Value *V, APInt DemandedMask,
Instruction *I = dyn_cast<Instruction>(V);
if (!I) return false; // Only analyze instructions.
- DemandedMask &= APInt::getAllOnesValue(BitWidth);
-
APInt LHSKnownZero(BitWidth, 0), LHSKnownOne(BitWidth, 0);
APInt &RHSKnownZero = KnownZero, &RHSKnownOne = KnownOne;
switch (I->getOpcode()) {
@@ -1280,7 +1279,7 @@ bool InstCombiner::SimplifyDemandedBits(Value *V, APInt DemandedMask,
if ((DemandedMask & APInt::getSignBit(BitWidth)) == 0) {
// Right fill the mask of bits for this SUB to demand the most
// significant bit and all those below it.
- unsigned NLZ = DemandedMask.countLeadingZeros();
+ uint32_t NLZ = DemandedMask.countLeadingZeros();
APInt DemandedFromOps(APInt::getAllOnesValue(BitWidth).lshr(NLZ));
if (SimplifyDemandedBits(I->getOperand(0), DemandedFromOps,
LHSKnownZero, LHSKnownOne, Depth+1))
@@ -4865,8 +4864,8 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
if (LHSI->hasOneUse()) {
// Otherwise strength reduce the shift into an and.
unsigned ShAmtVal = (unsigned)ShAmt->getZExtValue();
- uint64_t Val = (1ULL << (TypeBits-ShAmtVal))-1;
- Constant *Mask = ConstantInt::get(CI->getType(), Val);
+ Constant *Mask = ConstantInt::get(APInt::getLowBitsSet(TypeBits,
+ TypeBits - ShAmtVal));
Instruction *AndI =
BinaryOperator::createAnd(LHSI->getOperand(0),
@@ -5835,8 +5834,9 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
BinaryOperator::createShl(X, ConstantInt::get(Ty, ShiftDiff));
InsertNewInstBefore(Shift, I);
- APInt Mask(Ty->getMask().shl(ShiftAmt2));
- return BinaryOperator::createAnd(Shift, ConstantInt::get(Mask));
+ ConstantInt *Mask = ConstantInt::get(
+ APInt::getHighBitsSet(TypeBits, TypeBits - ShiftAmt2));
+ return BinaryOperator::createAnd(Shift, Mask);
}
// (X << C1) >>u C2 --> X >>u (C2-C1) & (-1 >> C2)
generated by cgit v1.1 at 2025-05-11 19:43:36 +0000