diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine')
8 files changed, 44 insertions, 28 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 1077121f8cb..174ec803627 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1572,6 +1572,11 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) { if (Instruction *R = FoldOpIntoSelect(I, SI)) return R; + // Try to fold constant sub into PHI values. + if (PHINode *PN = dyn_cast<PHINode>(Op1)) + if (Instruction *R = foldOpIntoPhi(I, PN)) + return R; + // C-(X+C2) --> (C-C2)-X Constant *C2; if (match(Op1, m_Add(m_Value(X), m_Constant(C2)))) diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp index e08c301ccdd..25683132c78 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -274,12 +274,12 @@ Instruction *InstCombiner::commonCastTransforms(CastInst &CI) { return NV; // If we are casting a PHI, then fold the cast into the PHI. - if (isa<PHINode>(Src)) { + if (auto *PN = dyn_cast<PHINode>(Src)) { // Don't do this if it would create a PHI node with an illegal type from a // legal type. if (!Src->getType()->isIntegerTy() || !CI.getType()->isIntegerTy() || shouldChangeType(CI.getType(), Src->getType())) - if (Instruction *NV = FoldOpIntoPhi(CI)) + if (Instruction *NV = foldOpIntoPhi(CI, PN)) return NV; } diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 5a292ef849e..bbafa9e9f46 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2709,7 +2709,7 @@ Instruction *InstCombiner::foldICmpInstWithConstantNotInt(ICmpInst &I) { // block. If in the same block, we're encouraging jump threading. If // not, we are just pessimizing the code by making an i1 phi. if (LHSI->getParent() == I.getParent()) - if (Instruction *NV = FoldOpIntoPhi(I)) + if (Instruction *NV = foldOpIntoPhi(I, cast<PHINode>(LHSI))) return NV; break; case Instruction::Select: { @@ -4873,7 +4873,7 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { // block. If in the same block, we're encouraging jump threading. If // not, we are just pessimizing the code by making an i1 phi. if (LHSI->getParent() == I.getParent()) - if (Instruction *NV = FoldOpIntoPhi(I)) + if (Instruction *NV = foldOpIntoPhi(I, cast<PHINode>(LHSI))) return NV; break; case Instruction::SIToFP: diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h index f163f57f54b..71000063ab3 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h +++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h @@ -569,7 +569,7 @@ private: /// Given a binary operator, cast instruction, or select which has a PHI node /// as operand #0, see if we can fold the instruction into the PHI (which is /// only possible if all operands to the PHI are constants). - Instruction *FoldOpIntoPhi(Instruction &I); + Instruction *foldOpIntoPhi(Instruction &I, PHINode *PN); /// Given an instruction with a select as one operand and a constant as the /// other operand, try to fold the binary operator into the select arguments. diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index a238f3f0505..f1ac82057e6 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -1455,16 +1455,16 @@ Instruction *InstCombiner::commonIRemTransforms(BinaryOperator &I) { if (SelectInst *SI = dyn_cast<SelectInst>(Op0I)) { if (Instruction *R = FoldOpIntoSelect(I, SI)) return R; - } else if (isa<PHINode>(Op0I)) { + } else if (auto *PN = dyn_cast<PHINode>(Op0I)) { using namespace llvm::PatternMatch; const APInt *Op1Int; if (match(Op1, m_APInt(Op1Int)) && !Op1Int->isMinValue() && (I.getOpcode() == Instruction::URem || !Op1Int->isMinSignedValue())) { - // FoldOpIntoPhi will speculate instructions to the end of the PHI's + // foldOpIntoPhi will speculate instructions to the end of the PHI's // predecessor blocks, so do this only if we know the srem or urem // will not fault. - if (Instruction *NV = FoldOpIntoPhi(I)) + if (Instruction *NV = foldOpIntoPhi(I, PN)) return NV; } } diff --git a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp index d8574175307..85e5b6ba2dc 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp @@ -457,8 +457,8 @@ Instruction *InstCombiner::FoldPHIArgZextsIntoPHI(PHINode &Phi) { } // The more common cases of a phi with no constant operands or just one - // variable operand are handled by FoldPHIArgOpIntoPHI() and FoldOpIntoPhi() - // respectively. FoldOpIntoPhi() wants to do the opposite transform that is + // variable operand are handled by FoldPHIArgOpIntoPHI() and foldOpIntoPhi() + // respectively. foldOpIntoPhi() wants to do the opposite transform that is // performed here. It tries to replicate a cast in the phi operand's basic // block to expose other folding opportunities. Thus, InstCombine will // infinite loop without this check. diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index b7099bec380..693b6c95c16 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -1384,11 +1384,11 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) { } // See if we can fold the select into a phi node if the condition is a select. - if (isa<PHINode>(SI.getCondition())) + if (auto *PN = dyn_cast<PHINode>(SI.getCondition())) // The true/false values have to be live in the PHI predecessor's blocks. if (canSelectOperandBeMappingIntoPredBlock(TrueVal, SI) && canSelectOperandBeMappingIntoPredBlock(FalseVal, SI)) - if (Instruction *NV = FoldOpIntoPhi(SI)) + if (Instruction *NV = foldOpIntoPhi(SI, PN)) return NV; if (SelectInst *TrueSI = dyn_cast<SelectInst>(TrueVal)) { diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp index 223fa2adc0c..88ef17bbc8f 100644 --- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -839,8 +839,29 @@ Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { return SelectInst::Create(SI->getCondition(), NewTV, NewFV, "", nullptr, SI); } -Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { - PHINode *PN = cast<PHINode>(I.getOperand(0)); +static Value *foldOperationIntoPhiValue(BinaryOperator *I, Value *InV, + InstCombiner *IC) { + bool ConstIsRHS = isa<Constant>(I->getOperand(1)); + Constant *C = cast<Constant>(I->getOperand(ConstIsRHS)); + + if (auto *InC = dyn_cast<Constant>(InV)) { + if (ConstIsRHS) + return ConstantExpr::get(I->getOpcode(), InC, C); + return ConstantExpr::get(I->getOpcode(), C, InC); + } + + Value *Op0 = InV, *Op1 = C; + if (!ConstIsRHS) + std::swap(Op0, Op1); + + Value *RI = IC->Builder->CreateBinOp(I->getOpcode(), Op0, Op1, "phitmp"); + auto *FPInst = dyn_cast<Instruction>(RI); + if (FPInst && isa<FPMathOperator>(FPInst)) + FPInst->copyFastMathFlags(I); + return RI; +} + +Instruction *InstCombiner::foldOpIntoPhi(Instruction &I, PHINode *PN) { unsigned NumPHIValues = PN->getNumIncomingValues(); if (NumPHIValues == 0) return nullptr; @@ -946,19 +967,9 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { C, "phitmp"); NewPN->addIncoming(InV, PN->getIncomingBlock(i)); } - } else if (I.getNumOperands() == 2) { - Constant *C = cast<Constant>(I.getOperand(1)); + } else if (auto *BO = dyn_cast<BinaryOperator>(&I)) { for (unsigned i = 0; i != NumPHIValues; ++i) { - Value *InV = nullptr; - if (Constant *InC = dyn_cast<Constant>(PN->getIncomingValue(i))) { - InV = ConstantExpr::get(I.getOpcode(), InC, C); - } else { - InV = Builder->CreateBinOp(cast<BinaryOperator>(I).getOpcode(), - PN->getIncomingValue(i), C, "phitmp"); - auto *FPInst = dyn_cast<Instruction>(InV); - if (FPInst && isa<FPMathOperator>(FPInst)) - FPInst->copyFastMathFlags(&I); - } + Value *InV = foldOperationIntoPhiValue(BO, PN->getIncomingValue(i), this); NewPN->addIncoming(InV, PN->getIncomingBlock(i)); } } else { @@ -990,8 +1001,8 @@ Instruction *InstCombiner::foldOpWithConstantIntoOperand(BinaryOperator &I) { if (auto *Sel = dyn_cast<SelectInst>(I.getOperand(0))) { if (Instruction *NewSel = FoldOpIntoSelect(I, Sel)) return NewSel; - } else if (isa<PHINode>(I.getOperand(0))) { - if (Instruction *NewPhi = FoldOpIntoPhi(I)) + } else if (auto *PN = dyn_cast<PHINode>(I.getOperand(0))) { + if (Instruction *NewPhi = foldOpIntoPhi(I, PN)) return NewPhi; } return nullptr; |
