forked from OSchip/llvm-project
parent
7aa0ad65ce
commit
10a2c38d83
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@ -984,75 +984,76 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
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if (Instruction *Result = visitSelectInstWithICmp(SI, ICI))
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return Result;
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if (Instruction *TI = dyn_cast<Instruction>(TrueVal))
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if (Instruction *FI = dyn_cast<Instruction>(FalseVal))
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if (TI->hasOneUse() && FI->hasOneUse()) {
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Instruction *AddOp = nullptr, *SubOp = nullptr;
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auto *TI = dyn_cast<Instruction>(TrueVal);
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auto *FI = dyn_cast<Instruction>(FalseVal);
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if (TI && FI && TI->hasOneUse() && FI->hasOneUse()) {
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Instruction *AddOp = nullptr, *SubOp = nullptr;
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// Turn (select C, (op X, Y), (op X, Z)) -> (op X, (select C, Y, Z))
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if (TI->getOpcode() == FI->getOpcode())
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if (Instruction *IV = FoldSelectOpOp(SI, TI, FI))
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return IV;
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// Turn (select C, (op X, Y), (op X, Z)) -> (op X, (select C, Y, Z))
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if (TI->getOpcode() == FI->getOpcode())
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if (Instruction *IV = FoldSelectOpOp(SI, TI, FI))
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return IV;
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// Turn select C, (X+Y), (X-Y) --> (X+(select C, Y, (-Y))). This is
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// even legal for FP.
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if ((TI->getOpcode() == Instruction::Sub &&
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FI->getOpcode() == Instruction::Add) ||
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(TI->getOpcode() == Instruction::FSub &&
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FI->getOpcode() == Instruction::FAdd)) {
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AddOp = FI; SubOp = TI;
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} else if ((FI->getOpcode() == Instruction::Sub &&
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TI->getOpcode() == Instruction::Add) ||
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(FI->getOpcode() == Instruction::FSub &&
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TI->getOpcode() == Instruction::FAdd)) {
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AddOp = TI; SubOp = FI;
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}
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// Turn select C, (X+Y), (X-Y) --> (X+(select C, Y, (-Y))). This is
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// even legal for FP.
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if ((TI->getOpcode() == Instruction::Sub &&
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FI->getOpcode() == Instruction::Add) ||
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(TI->getOpcode() == Instruction::FSub &&
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FI->getOpcode() == Instruction::FAdd)) {
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AddOp = FI;
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SubOp = TI;
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} else if ((FI->getOpcode() == Instruction::Sub &&
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TI->getOpcode() == Instruction::Add) ||
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(FI->getOpcode() == Instruction::FSub &&
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TI->getOpcode() == Instruction::FAdd)) {
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AddOp = TI;
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SubOp = FI;
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}
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if (AddOp) {
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Value *OtherAddOp = nullptr;
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if (SubOp->getOperand(0) == AddOp->getOperand(0)) {
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OtherAddOp = AddOp->getOperand(1);
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} else if (SubOp->getOperand(0) == AddOp->getOperand(1)) {
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OtherAddOp = AddOp->getOperand(0);
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}
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if (OtherAddOp) {
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// So at this point we know we have (Y -> OtherAddOp):
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// select C, (add X, Y), (sub X, Z)
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Value *NegVal; // Compute -Z
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if (SI.getType()->isFPOrFPVectorTy()) {
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NegVal = Builder->CreateFNeg(SubOp->getOperand(1));
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if (Instruction *NegInst = dyn_cast<Instruction>(NegVal)) {
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FastMathFlags Flags = AddOp->getFastMathFlags();
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Flags &= SubOp->getFastMathFlags();
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NegInst->setFastMathFlags(Flags);
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}
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} else {
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NegVal = Builder->CreateNeg(SubOp->getOperand(1));
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}
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Value *NewTrueOp = OtherAddOp;
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Value *NewFalseOp = NegVal;
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if (AddOp != TI)
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std::swap(NewTrueOp, NewFalseOp);
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Value *NewSel =
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Builder->CreateSelect(CondVal, NewTrueOp,
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NewFalseOp, SI.getName() + ".p");
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if (SI.getType()->isFPOrFPVectorTy()) {
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Instruction *RI =
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BinaryOperator::CreateFAdd(SubOp->getOperand(0), NewSel);
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FastMathFlags Flags = AddOp->getFastMathFlags();
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Flags &= SubOp->getFastMathFlags();
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RI->setFastMathFlags(Flags);
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return RI;
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} else
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return BinaryOperator::CreateAdd(SubOp->getOperand(0), NewSel);
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}
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}
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if (AddOp) {
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Value *OtherAddOp = nullptr;
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if (SubOp->getOperand(0) == AddOp->getOperand(0)) {
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OtherAddOp = AddOp->getOperand(1);
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} else if (SubOp->getOperand(0) == AddOp->getOperand(1)) {
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OtherAddOp = AddOp->getOperand(0);
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}
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if (OtherAddOp) {
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// So at this point we know we have (Y -> OtherAddOp):
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// select C, (add X, Y), (sub X, Z)
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Value *NegVal; // Compute -Z
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if (SI.getType()->isFPOrFPVectorTy()) {
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NegVal = Builder->CreateFNeg(SubOp->getOperand(1));
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if (Instruction *NegInst = dyn_cast<Instruction>(NegVal)) {
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FastMathFlags Flags = AddOp->getFastMathFlags();
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Flags &= SubOp->getFastMathFlags();
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NegInst->setFastMathFlags(Flags);
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}
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} else {
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NegVal = Builder->CreateNeg(SubOp->getOperand(1));
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}
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Value *NewTrueOp = OtherAddOp;
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Value *NewFalseOp = NegVal;
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if (AddOp != TI)
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std::swap(NewTrueOp, NewFalseOp);
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Value *NewSel = Builder->CreateSelect(CondVal, NewTrueOp, NewFalseOp,
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SI.getName() + ".p");
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if (SI.getType()->isFPOrFPVectorTy()) {
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Instruction *RI =
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BinaryOperator::CreateFAdd(SubOp->getOperand(0), NewSel);
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FastMathFlags Flags = AddOp->getFastMathFlags();
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Flags &= SubOp->getFastMathFlags();
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RI->setFastMathFlags(Flags);
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return RI;
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} else
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return BinaryOperator::CreateAdd(SubOp->getOperand(0), NewSel);
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}
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}
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}
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// See if we can fold the select into one of our operands.
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if (SI.getType()->isIntOrIntVectorTy() || SI.getType()->isFPOrFPVectorTy()) {
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if (Instruction *FoldI = FoldSelectIntoOp(SI, TrueVal, FalseVal))
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