mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-26 21:32:10 +00:00
This is a bulk commit that implements the following primary improvements:
* We can now fold cast instructions into select instructions that
have at least one constant operand.
* We now optimize expressions more aggressively based on bits that are
known to be zero. These optimizations occur a lot in code that uses
bitfields even in simple ways.
* We now turn more cast-cast sequences into AND instructions. Before we
would only do this if it if all types were unsigned. Now only the
middle type needs to be unsigned (guaranteeing a zero extend).
* We transform sign extensions into zero extensions in several cases.
This corresponds to these test/Regression/Transforms/InstCombine testcases:
2004-11-22-Missed-and-fold.ll
and.ll: test28-29
cast.ll: test21-24
and-or-and.ll
cast-cast-to-and.ll
zeroext-and-reduce.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19220 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
parent
0f75849116
commit
6e7ba45460
@ -486,31 +486,60 @@ struct AddMaskingAnd {
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}
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};
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static Value *FoldOperationIntoSelectOperand(Instruction &BI, Value *SO,
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static Value *FoldOperationIntoSelectOperand(Instruction &I, Value *SO,
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InstCombiner *IC) {
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if (isa<CastInst>(I)) {
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if (Constant *SOC = dyn_cast<Constant>(SO))
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return ConstantExpr::getCast(SOC, I.getType());
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return IC->InsertNewInstBefore(new CastInst(SO, I.getType(),
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SO->getName() + ".cast"), I);
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}
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// Figure out if the constant is the left or the right argument.
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bool ConstIsRHS = isa<Constant>(BI.getOperand(1));
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Constant *ConstOperand = cast<Constant>(BI.getOperand(ConstIsRHS));
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bool ConstIsRHS = isa<Constant>(I.getOperand(1));
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Constant *ConstOperand = cast<Constant>(I.getOperand(ConstIsRHS));
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if (Constant *SOC = dyn_cast<Constant>(SO)) {
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if (ConstIsRHS)
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return ConstantExpr::get(BI.getOpcode(), SOC, ConstOperand);
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return ConstantExpr::get(BI.getOpcode(), ConstOperand, SOC);
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return ConstantExpr::get(I.getOpcode(), SOC, ConstOperand);
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return ConstantExpr::get(I.getOpcode(), ConstOperand, SOC);
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}
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Value *Op0 = SO, *Op1 = ConstOperand;
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if (!ConstIsRHS)
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std::swap(Op0, Op1);
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Instruction *New;
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if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&BI))
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New = BinaryOperator::create(BO->getOpcode(), Op0, Op1);
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else if (ShiftInst *SI = dyn_cast<ShiftInst>(&BI))
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New = new ShiftInst(SI->getOpcode(), Op0, Op1);
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if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&I))
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New = BinaryOperator::create(BO->getOpcode(), Op0, Op1,SO->getName()+".op");
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else if (ShiftInst *SI = dyn_cast<ShiftInst>(&I))
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New = new ShiftInst(SI->getOpcode(), Op0, Op1, SO->getName()+".sh");
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else {
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assert(0 && "Unknown binary instruction type!");
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abort();
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}
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return IC->InsertNewInstBefore(New, BI);
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return IC->InsertNewInstBefore(New, I);
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}
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// FoldOpIntoSelect - Given an instruction with a select as one operand and a
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// constant as the other operand, try to fold the binary operator into the
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// select arguments. This also works for Cast instructions, which obviously do
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// not have a second operand.
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static Instruction *FoldOpIntoSelect(Instruction &Op, SelectInst *SI,
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InstCombiner *IC) {
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// Don't modify shared select instructions
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if (!SI->hasOneUse()) return 0;
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Value *TV = SI->getOperand(1);
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Value *FV = SI->getOperand(2);
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if (isa<Constant>(TV) || isa<Constant>(FV)) {
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Value *SelectTrueVal = FoldOperationIntoSelectOperand(Op, TV, IC);
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Value *SelectFalseVal = FoldOperationIntoSelectOperand(Op, FV, IC);
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return new SelectInst(SI->getCondition(), SelectTrueVal,
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SelectFalseVal);
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}
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return 0;
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}
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@ -555,26 +584,6 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) {
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return ReplaceInstUsesWith(I, NewPN);
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}
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// FoldBinOpIntoSelect - Given an instruction with a select as one operand and a
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// constant as the other operand, try to fold the binary operator into the
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// select arguments.
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static Instruction *FoldBinOpIntoSelect(Instruction &BI, SelectInst *SI,
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InstCombiner *IC) {
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// Don't modify shared select instructions
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if (!SI->hasOneUse()) return 0;
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Value *TV = SI->getOperand(1);
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Value *FV = SI->getOperand(2);
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if (isa<Constant>(TV) || isa<Constant>(FV)) {
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Value *SelectTrueVal = FoldOperationIntoSelectOperand(BI, TV, IC);
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Value *SelectFalseVal = FoldOperationIntoSelectOperand(BI, FV, IC);
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return new SelectInst(SI->getCondition(), SelectTrueVal,
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SelectFalseVal);
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}
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return 0;
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}
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Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
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bool Changed = SimplifyCommutative(I);
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Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
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@ -667,10 +676,9 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
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}
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}
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// Try to fold constant add into select arguments.
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if (SelectInst *SI = dyn_cast<SelectInst>(LHS))
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if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
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if (Instruction *R = FoldOpIntoSelect(I, SI, this))
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return R;
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}
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@ -761,7 +769,7 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
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// Try to fold constant sub into select arguments.
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if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
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if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
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if (Instruction *R = FoldOpIntoSelect(I, SI, this))
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return R;
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if (isa<PHINode>(Op0))
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@ -889,7 +897,7 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) {
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// Try to fold constant mul into select arguments.
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if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
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if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
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if (Instruction *R = FoldOpIntoSelect(I, SI, this))
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return R;
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if (isa<PHINode>(Op0))
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@ -990,7 +998,7 @@ Instruction *InstCombiner::visitDiv(BinaryOperator &I) {
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if (!RHS->isNullValue()) {
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if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
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if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
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if (Instruction *R = FoldOpIntoSelect(I, SI, this))
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return R;
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if (isa<PHINode>(Op0))
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if (Instruction *NV = FoldOpIntoPhi(I))
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@ -1066,7 +1074,7 @@ Instruction *InstCombiner::visitRem(BinaryOperator &I) {
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if (!RHS->isNullValue()) {
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if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
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if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
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if (Instruction *R = FoldOpIntoSelect(I, SI, this))
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return R;
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if (isa<PHINode>(Op0))
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if (Instruction *NV = FoldOpIntoPhi(I))
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@ -1251,6 +1259,70 @@ struct FoldSetCCLogical {
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};
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/// MaskedValueIsZero - Return true if 'V & Mask' is known to be zero. We use
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/// this predicate to simplify operations downstream. V and Mask are known to
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/// be the same type.
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static bool MaskedValueIsZero(Value *V, ConstantIntegral *Mask) {
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if (isa<UndefValue>(V) || Mask->isNullValue())
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return true;
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if (ConstantIntegral *CI = dyn_cast<ConstantIntegral>(V))
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return ConstantExpr::getAnd(CI, Mask)->isNullValue();
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if (Instruction *I = dyn_cast<Instruction>(V)) {
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switch (I->getOpcode()) {
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case Instruction::And:
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// (X & C1) & C2 == 0 iff C1 & C2 == 0.
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if (ConstantIntegral *CI = dyn_cast<ConstantIntegral>(I->getOperand(1)))
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if (ConstantExpr::getAnd(CI, Mask)->isNullValue())
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return true;
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break;
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case Instruction::Cast: {
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const Type *SrcTy = I->getOperand(0)->getType();
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if (SrcTy->isIntegral()) {
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// (cast <ty> X to int) & C2 == 0 iff <ty> could not have contained C2.
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if (SrcTy->isUnsigned() && // Only handle zero ext.
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ConstantExpr::getCast(Mask, SrcTy)->isNullValue())
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return true;
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// If this is a noop cast, recurse.
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if (SrcTy != Type::BoolTy)
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if ((SrcTy->isSigned() && SrcTy->getUnsignedVersion() ==I->getType()) ||
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SrcTy->getSignedVersion() == I->getType()) {
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Constant *NewMask =
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ConstantExpr::getCast(Mask, I->getOperand(0)->getType());
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return MaskedValueIsZero(I->getOperand(0),
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cast<ConstantIntegral>(NewMask));
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}
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}
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break;
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}
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case Instruction::Shl:
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// (shl X, C1) & C2 == 0 iff (-1 << C1) & C2 == 0
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if (ConstantUInt *SA = dyn_cast<ConstantUInt>(I->getOperand(1))) {
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Constant *C1 = ConstantIntegral::getAllOnesValue(I->getType());
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C1 = ConstantExpr::getShl(C1, SA);
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C1 = ConstantExpr::getAnd(C1, Mask);
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if (C1->isNullValue())
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return true;
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}
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break;
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case Instruction::Shr:
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// (ushr X, C1) & C2 == 0 iff (-1 >> C1) & C2 == 0
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if (ConstantUInt *SA = dyn_cast<ConstantUInt>(I->getOperand(1)))
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if (I->getType()->isUnsigned()) {
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Constant *C1 = ConstantIntegral::getAllOnesValue(I->getType());
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C1 = ConstantExpr::getShr(C1, SA);
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C1 = ConstantExpr::getAnd(C1, Mask);
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if (C1->isNullValue())
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return true;
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}
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break;
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}
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}
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return false;
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}
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// OptAndOp - This handles expressions of the form ((val OP C1) & C2). Where
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// the Op parameter is 'OP', OpRHS is 'C1', and AndRHS is 'C2'. Op is
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// guaranteed to be either a shift instruction or a binary operator.
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@ -1265,10 +1337,7 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op,
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switch (Op->getOpcode()) {
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case Instruction::Xor:
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if (Together->isNullValue()) {
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// (X ^ C1) & C2 --> (X & C2) iff (C1&C2) == 0
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return BinaryOperator::createAnd(X, AndRHS);
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} else if (Op->hasOneUse()) {
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if (Op->hasOneUse()) {
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// (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
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std::string OpName = Op->getName(); Op->setName("");
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Instruction *And = BinaryOperator::createAnd(X, AndRHS, OpName);
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@ -1277,20 +1346,15 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op,
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}
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break;
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case Instruction::Or:
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// (X | C1) & C2 --> X & C2 iff C1 & C1 == 0
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if (Together->isNullValue())
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return BinaryOperator::createAnd(X, AndRHS);
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else {
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if (Together == AndRHS) // (X | C) & C --> C
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return ReplaceInstUsesWith(TheAnd, AndRHS);
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if (Together == AndRHS) // (X | C) & C --> C
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return ReplaceInstUsesWith(TheAnd, AndRHS);
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if (Op->hasOneUse() && Together != OpRHS) {
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// (X | C1) & C2 --> (X | (C1&C2)) & C2
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std::string Op0Name = Op->getName(); Op->setName("");
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Instruction *Or = BinaryOperator::createOr(X, Together, Op0Name);
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InsertNewInstBefore(Or, TheAnd);
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return BinaryOperator::createAnd(Or, AndRHS);
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}
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if (Op->hasOneUse() && Together != OpRHS) {
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// (X | C1) & C2 --> (X | (C1&C2)) & C2
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std::string Op0Name = Op->getName(); Op->setName("");
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Instruction *Or = BinaryOperator::createOr(X, Together, Op0Name);
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InsertNewInstBefore(Or, TheAnd);
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return BinaryOperator::createAnd(Or, AndRHS);
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}
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break;
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case Instruction::Add:
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@ -1445,27 +1509,103 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
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if (isa<UndefValue>(Op1)) // X & undef -> 0
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return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
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// and X, X = X and X, 0 == 0
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if (Op0 == Op1 || Op1 == Constant::getNullValue(I.getType()))
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// and X, X = X
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if (Op0 == Op1)
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return ReplaceInstUsesWith(I, Op1);
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// and X, -1 == X
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if (ConstantIntegral *RHS = dyn_cast<ConstantIntegral>(Op1)) {
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if (RHS->isAllOnesValue())
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if (ConstantIntegral *AndRHS = dyn_cast<ConstantIntegral>(Op1)) {
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if (AndRHS->isAllOnesValue()) // and X, -1 == X
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return ReplaceInstUsesWith(I, Op0);
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if (MaskedValueIsZero(Op0, AndRHS)) // LHS & RHS == 0
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return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
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// If the mask is not masking out any bits, there is no reason to do the
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// and in the first place.
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if (MaskedValueIsZero(Op0,
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cast<ConstantIntegral>(ConstantExpr::getNot(AndRHS))))
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return ReplaceInstUsesWith(I, Op0);
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// Optimize a variety of ((val OP C1) & C2) combinations...
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if (isa<BinaryOperator>(Op0) || isa<ShiftInst>(Op0)) {
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Instruction *Op0I = cast<Instruction>(Op0);
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Value *X = Op0I->getOperand(0);
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Value *Op0LHS = Op0I->getOperand(0);
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Value *Op0RHS = Op0I->getOperand(1);
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switch (Op0I->getOpcode()) {
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case Instruction::Xor:
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case Instruction::Or:
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// (X ^ V) & C2 --> (X & C2) iff (V & C2) == 0
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// (X | V) & C2 --> (X & C2) iff (V & C2) == 0
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if (MaskedValueIsZero(Op0LHS, AndRHS))
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return BinaryOperator::createAnd(Op0RHS, AndRHS);
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if (MaskedValueIsZero(Op0RHS, AndRHS))
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return BinaryOperator::createAnd(Op0LHS, AndRHS);
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break;
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case Instruction::And:
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// (X & V) & C2 --> 0 iff (V & C2) == 0
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if (MaskedValueIsZero(Op0LHS, AndRHS) ||
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MaskedValueIsZero(Op0RHS, AndRHS))
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return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
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break;
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}
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if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
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if (Instruction *Res = OptAndOp(Op0I, Op0CI, RHS, I))
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if (Instruction *Res = OptAndOp(Op0I, Op0CI, AndRHS, I))
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return Res;
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} else if (CastInst *CI = dyn_cast<CastInst>(Op0)) {
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const Type *SrcTy = CI->getOperand(0)->getType();
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// If this is an integer sign or zero extension instruction.
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if (SrcTy->isIntegral() &&
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SrcTy->getPrimitiveSize() < CI->getType()->getPrimitiveSize()) {
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if (SrcTy->isUnsigned()) {
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// See if this and is clearing out bits that are known to be zero
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// anyway (due to the zero extension).
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Constant *Mask = ConstantIntegral::getAllOnesValue(SrcTy);
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Mask = ConstantExpr::getZeroExtend(Mask, CI->getType());
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Constant *Result = ConstantExpr::getAnd(Mask, AndRHS);
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if (Result == Mask) // The "and" isn't doing anything, remove it.
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return ReplaceInstUsesWith(I, CI);
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if (Result != AndRHS) { // Reduce the and RHS constant.
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I.setOperand(1, Result);
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return &I;
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}
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} else {
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if (CI->hasOneUse() && SrcTy->isInteger()) {
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// We can only do this if all of the sign bits brought in are masked
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// out. Compute this by first getting 0000011111, then inverting
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// it.
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Constant *Mask = ConstantIntegral::getAllOnesValue(SrcTy);
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Mask = ConstantExpr::getZeroExtend(Mask, CI->getType());
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Mask = ConstantExpr::getNot(Mask); // 1's in the new bits.
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if (ConstantExpr::getAnd(Mask, AndRHS)->isNullValue()) {
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// If the and is clearing all of the sign bits, change this to a
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// zero extension cast. To do this, cast the cast input to
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// unsigned, then to the requested size.
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Value *CastOp = CI->getOperand(0);
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Instruction *NC =
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new CastInst(CastOp, CastOp->getType()->getUnsignedVersion(),
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CI->getName()+".uns");
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NC = InsertNewInstBefore(NC, I);
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// Finally, insert a replacement for CI.
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NC = new CastInst(NC, CI->getType(), CI->getName());
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CI->setName("");
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NC = InsertNewInstBefore(NC, I);
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WorkList.push_back(CI); // Delete CI later.
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I.setOperand(0, NC);
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return &I; // The AND operand was modified.
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}
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}
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}
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}
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}
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// Try to fold constant and into select arguments.
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if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
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if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
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if (Instruction *R = FoldOpIntoSelect(I, SI, this))
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return R;
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if (isa<PHINode>(Op0))
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if (Instruction *NV = FoldOpIntoPhi(I))
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@ -1599,8 +1739,11 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
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// or X, -1 == -1
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if (ConstantIntegral *RHS = dyn_cast<ConstantIntegral>(Op1)) {
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if (RHS->isAllOnesValue())
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return ReplaceInstUsesWith(I, Op1);
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// If X is known to only contain bits that already exist in RHS, just
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// replace this instruction with RHS directly.
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if (MaskedValueIsZero(Op0,
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cast<ConstantIntegral>(ConstantExpr::getNot(RHS))))
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return ReplaceInstUsesWith(I, RHS);
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ConstantInt *C1; Value *X;
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// (X & C1) | C2 --> (X | C2) & (C1|C2)
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@ -1622,7 +1765,7 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
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||||
// Try to fold constant and into select arguments.
|
||||
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
|
||||
if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
|
||||
if (Instruction *R = FoldOpIntoSelect(I, SI, this))
|
||||
return R;
|
||||
if (isa<PHINode>(Op0))
|
||||
if (Instruction *NV = FoldOpIntoPhi(I))
|
||||
@ -1840,7 +1983,7 @@ Instruction *InstCombiner::visitXor(BinaryOperator &I) {
|
||||
|
||||
// Try to fold constant and into select arguments.
|
||||
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
|
||||
if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
|
||||
if (Instruction *R = FoldOpIntoSelect(I, SI, this))
|
||||
return R;
|
||||
if (isa<PHINode>(Op0))
|
||||
if (Instruction *NV = FoldOpIntoPhi(I))
|
||||
@ -2671,7 +2814,7 @@ Instruction *InstCombiner::visitShiftInst(ShiftInst &I) {
|
||||
// Try to fold constant and into select arguments.
|
||||
if (isa<Constant>(Op0))
|
||||
if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
|
||||
if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
|
||||
if (Instruction *R = FoldOpIntoSelect(I, SI, this))
|
||||
return R;
|
||||
|
||||
if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(Op1)) {
|
||||
@ -2697,15 +2840,48 @@ Instruction *InstCombiner::visitShiftInst(ShiftInst &I) {
|
||||
|
||||
// Try to fold constant and into select arguments.
|
||||
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
|
||||
if (Instruction *R = FoldBinOpIntoSelect(I, SI, this))
|
||||
if (Instruction *R = FoldOpIntoSelect(I, SI, this))
|
||||
return R;
|
||||
if (isa<PHINode>(Op0))
|
||||
if (Instruction *NV = FoldOpIntoPhi(I))
|
||||
return NV;
|
||||
|
||||
// If the operand is an bitwise operator with a constant RHS, and the
|
||||
// shift is the only use, we can pull it out of the shift.
|
||||
if (Op0->hasOneUse())
|
||||
if (Op0->hasOneUse()) {
|
||||
// If this is a SHL of a sign-extending cast, see if we can turn the input
|
||||
// into a zero extending cast (a simple strength reduction).
|
||||
if (CastInst *CI = dyn_cast<CastInst>(Op0)) {
|
||||
const Type *SrcTy = CI->getOperand(0)->getType();
|
||||
if (isLeftShift && SrcTy->isInteger() && SrcTy->isSigned() &&
|
||||
SrcTy->getPrimitiveSize() < CI->getType()->getPrimitiveSize()) {
|
||||
// We can change it to a zero extension if we are shifting out all of
|
||||
// the sign extended bits. To check this, form a mask of all of the
|
||||
// sign extend bits, then shift them left and see if we have anything
|
||||
// left.
|
||||
Constant *Mask = ConstantIntegral::getAllOnesValue(SrcTy); // 1111
|
||||
Mask = ConstantExpr::getZeroExtend(Mask, CI->getType()); // 00001111
|
||||
Mask = ConstantExpr::getNot(Mask); // 1's in the sign bits: 11110000
|
||||
if (ConstantExpr::getShl(Mask, CUI)->isNullValue()) {
|
||||
// If the shift is nuking all of the sign bits, change this to a
|
||||
// zero extension cast. To do this, cast the cast input to
|
||||
// unsigned, then to the requested size.
|
||||
Value *CastOp = CI->getOperand(0);
|
||||
Instruction *NC =
|
||||
new CastInst(CastOp, CastOp->getType()->getUnsignedVersion(),
|
||||
CI->getName()+".uns");
|
||||
NC = InsertNewInstBefore(NC, I);
|
||||
// Finally, insert a replacement for CI.
|
||||
NC = new CastInst(NC, CI->getType(), CI->getName());
|
||||
CI->setName("");
|
||||
NC = InsertNewInstBefore(NC, I);
|
||||
WorkList.push_back(CI); // Delete CI later.
|
||||
I.setOperand(0, NC);
|
||||
return &I; // The SHL operand was modified.
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// If the operand is an bitwise operator with a constant RHS, and the
|
||||
// shift is the only use, we can pull it out of the shift.
|
||||
if (BinaryOperator *Op0BO = dyn_cast<BinaryOperator>(Op0))
|
||||
if (ConstantInt *Op0C = dyn_cast<ConstantInt>(Op0BO->getOperand(1))) {
|
||||
bool isValid = true; // Valid only for And, Or, Xor
|
||||
@ -2749,6 +2925,7 @@ Instruction *InstCombiner::visitShiftInst(ShiftInst &I) {
|
||||
NewRHS);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// If this is a shift of a shift, see if we can fold the two together...
|
||||
if (ShiftInst *Op0SI = dyn_cast<ShiftInst>(Op0))
|
||||
@ -2926,9 +3103,10 @@ Instruction *InstCombiner::visitCastInst(CastInst &CI) {
|
||||
// If casting the result of another cast instruction, try to eliminate this
|
||||
// one!
|
||||
//
|
||||
if (CastInst *CSrc = dyn_cast<CastInst>(Src)) {
|
||||
if (isEliminableCastOfCast(CSrc->getOperand(0)->getType(),
|
||||
CSrc->getType(), CI.getType(), TD)) {
|
||||
if (CastInst *CSrc = dyn_cast<CastInst>(Src)) { // A->B->C cast
|
||||
Value *A = CSrc->getOperand(0);
|
||||
if (isEliminableCastOfCast(A->getType(), CSrc->getType(),
|
||||
CI.getType(), TD)) {
|
||||
// This instruction now refers directly to the cast's src operand. This
|
||||
// has a good chance of making CSrc dead.
|
||||
CI.setOperand(0, CSrc->getOperand(0));
|
||||
@ -2938,15 +3116,24 @@ Instruction *InstCombiner::visitCastInst(CastInst &CI) {
|
||||
// If this is an A->B->A cast, and we are dealing with integral types, try
|
||||
// to convert this into a logical 'and' instruction.
|
||||
//
|
||||
if (CSrc->getOperand(0)->getType() == CI.getType() &&
|
||||
if (A->getType()->isInteger() &&
|
||||
CI.getType()->isInteger() && CSrc->getType()->isInteger() &&
|
||||
CI.getType()->isUnsigned() && CSrc->getType()->isUnsigned() &&
|
||||
CSrc->getType()->getPrimitiveSize() < CI.getType()->getPrimitiveSize()){
|
||||
CSrc->getType()->isUnsigned() && // B->A cast must zero extend
|
||||
CSrc->getType()->getPrimitiveSize() < CI.getType()->getPrimitiveSize()&&
|
||||
A->getType()->getPrimitiveSize() == CI.getType()->getPrimitiveSize()) {
|
||||
assert(CSrc->getType() != Type::ULongTy &&
|
||||
"Cannot have type bigger than ulong!");
|
||||
uint64_t AndValue = (1ULL << CSrc->getType()->getPrimitiveSize()*8)-1;
|
||||
Constant *AndOp = ConstantUInt::get(CI.getType(), AndValue);
|
||||
return BinaryOperator::createAnd(CSrc->getOperand(0), AndOp);
|
||||
Constant *AndOp = ConstantUInt::get(A->getType()->getUnsignedVersion(),
|
||||
AndValue);
|
||||
AndOp = ConstantExpr::getCast(AndOp, A->getType());
|
||||
Instruction *And = BinaryOperator::createAnd(CSrc->getOperand(0), AndOp);
|
||||
if (And->getType() != CI.getType()) {
|
||||
And->setName(CSrc->getName()+".mask");
|
||||
InsertNewInstBefore(And, CI);
|
||||
And = new CastInst(And, CI.getType());
|
||||
}
|
||||
return And;
|
||||
}
|
||||
}
|
||||
|
||||
@ -3001,6 +3188,9 @@ Instruction *InstCombiner::visitCastInst(CastInst &CI) {
|
||||
}
|
||||
}
|
||||
|
||||
if (SelectInst *SI = dyn_cast<SelectInst>(Src))
|
||||
if (Instruction *NV = FoldOpIntoSelect(CI, SI, this))
|
||||
return NV;
|
||||
if (isa<PHINode>(Src))
|
||||
if (Instruction *NV = FoldOpIntoPhi(CI))
|
||||
return NV;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user