diff options
Diffstat (limited to 'contrib/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp')
| -rw-r--r-- | contrib/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp | 740 |
1 files changed, 536 insertions, 204 deletions
diff --git a/contrib/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/contrib/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp index 191a101e0a30..d3648e2d0505 100644 --- a/contrib/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/contrib/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -33,7 +33,6 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "instcombine" #include "llvm/Transforms/Scalar.h" #include "InstCombine.h" #include "llvm-c/Initialization.h" @@ -43,14 +42,15 @@ #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/MemoryBuiltins.h" +#include "llvm/Analysis/ValueTracking.h" +#include "llvm/IR/CFG.h" #include "llvm/IR/DataLayout.h" +#include "llvm/IR/GetElementPtrTypeIterator.h" #include "llvm/IR/IntrinsicInst.h" -#include "llvm/Support/CFG.h" +#include "llvm/IR/PatternMatch.h" +#include "llvm/IR/ValueHandle.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" -#include "llvm/Support/GetElementPtrTypeIterator.h" -#include "llvm/Support/PatternMatch.h" -#include "llvm/Support/ValueHandle.h" #include "llvm/Target/TargetLibraryInfo.h" #include "llvm/Transforms/Utils/Local.h" #include <algorithm> @@ -58,6 +58,8 @@ using namespace llvm; using namespace llvm::PatternMatch; +#define DEBUG_TYPE "instcombine" + STATISTIC(NumCombined , "Number of insts combined"); STATISTIC(NumConstProp, "Number of constant folds"); STATISTIC(NumDeadInst , "Number of dead inst eliminated"); @@ -103,13 +105,13 @@ Value *InstCombiner::EmitGEPOffset(User *GEP) { bool InstCombiner::ShouldChangeType(Type *From, Type *To) const { assert(From->isIntegerTy() && To->isIntegerTy()); - // If we don't have TD, we don't know if the source/dest are legal. - if (!TD) return false; + // If we don't have DL, we don't know if the source/dest are legal. + if (!DL) return false; unsigned FromWidth = From->getPrimitiveSizeInBits(); unsigned ToWidth = To->getPrimitiveSizeInBits(); - bool FromLegal = TD->isLegalInteger(FromWidth); - bool ToLegal = TD->isLegalInteger(ToWidth); + bool FromLegal = DL->isLegalInteger(FromWidth); + bool ToLegal = DL->isLegalInteger(ToWidth); // If this is a legal integer from type, and the result would be an illegal // type, don't do the transformation. @@ -221,7 +223,7 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) { Value *C = I.getOperand(1); // Does "B op C" simplify? - if (Value *V = SimplifyBinOp(Opcode, B, C, TD)) { + if (Value *V = SimplifyBinOp(Opcode, B, C, DL)) { // It simplifies to V. Form "A op V". I.setOperand(0, A); I.setOperand(1, V); @@ -250,7 +252,7 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) { Value *C = Op1->getOperand(1); // Does "A op B" simplify? - if (Value *V = SimplifyBinOp(Opcode, A, B, TD)) { + if (Value *V = SimplifyBinOp(Opcode, A, B, DL)) { // It simplifies to V. Form "V op C". I.setOperand(0, V); I.setOperand(1, C); @@ -272,7 +274,7 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) { Value *C = I.getOperand(1); // Does "C op A" simplify? - if (Value *V = SimplifyBinOp(Opcode, C, A, TD)) { + if (Value *V = SimplifyBinOp(Opcode, C, A, DL)) { // It simplifies to V. Form "V op B". I.setOperand(0, V); I.setOperand(1, B); @@ -292,7 +294,7 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) { Value *C = Op1->getOperand(1); // Does "C op A" simplify? - if (Value *V = SimplifyBinOp(Opcode, C, A, TD)) { + if (Value *V = SimplifyBinOp(Opcode, C, A, DL)) { // It simplifies to V. Form "B op V". I.setOperand(0, B); I.setOperand(1, V); @@ -319,6 +321,12 @@ bool InstCombiner::SimplifyAssociativeOrCommutative(BinaryOperator &I) { Constant *Folded = ConstantExpr::get(Opcode, C1, C2); BinaryOperator *New = BinaryOperator::Create(Opcode, A, B); + if (isa<FPMathOperator>(New)) { + FastMathFlags Flags = I.getFastMathFlags(); + Flags &= Op0->getFastMathFlags(); + Flags &= Op1->getFastMathFlags(); + New->setFastMathFlags(Flags); + } InsertNewInstWith(New, I); New->takeName(Op1); I.setOperand(0, New); @@ -388,6 +396,127 @@ static bool RightDistributesOverLeft(Instruction::BinaryOps LOp, return false; } +/// This function returns identity value for given opcode, which can be used to +/// factor patterns like (X * 2) + X ==> (X * 2) + (X * 1) ==> X * (2 + 1). +static Value *getIdentityValue(Instruction::BinaryOps OpCode, Value *V) { + if (isa<Constant>(V)) + return nullptr; + + if (OpCode == Instruction::Mul) + return ConstantInt::get(V->getType(), 1); + + // TODO: We can handle other cases e.g. Instruction::And, Instruction::Or etc. + + return nullptr; +} + +/// This function factors binary ops which can be combined using distributive +/// laws. This also factor SHL as MUL e.g. SHL(X, 2) ==> MUL(X, 4). +static Instruction::BinaryOps +getBinOpsForFactorization(BinaryOperator *Op, Value *&LHS, Value *&RHS) { + if (!Op) + return Instruction::BinaryOpsEnd; + + if (Op->getOpcode() == Instruction::Shl) { + if (Constant *CST = dyn_cast<Constant>(Op->getOperand(1))) { + // The multiplier is really 1 << CST. + RHS = ConstantExpr::getShl(ConstantInt::get(Op->getType(), 1), CST); + LHS = Op->getOperand(0); + return Instruction::Mul; + } + } + + // TODO: We can add other conversions e.g. shr => div etc. + + LHS = Op->getOperand(0); + RHS = Op->getOperand(1); + return Op->getOpcode(); +} + +/// This tries to simplify binary operations by factorizing out common terms +/// (e. g. "(A*B)+(A*C)" -> "A*(B+C)"). +static Value *tryFactorization(InstCombiner::BuilderTy *Builder, + const DataLayout *DL, BinaryOperator &I, + Instruction::BinaryOps InnerOpcode, Value *A, + Value *B, Value *C, Value *D) { + + // If any of A, B, C, D are null, we can not factor I, return early. + // Checking A and C should be enough. + if (!A || !C || !B || !D) + return nullptr; + + Value *SimplifiedInst = nullptr; + Value *LHS = I.getOperand(0), *RHS = I.getOperand(1); + Instruction::BinaryOps TopLevelOpcode = I.getOpcode(); + + // Does "X op' Y" always equal "Y op' X"? + bool InnerCommutative = Instruction::isCommutative(InnerOpcode); + + // Does "X op' (Y op Z)" always equal "(X op' Y) op (X op' Z)"? + if (LeftDistributesOverRight(InnerOpcode, TopLevelOpcode)) + // Does the instruction have the form "(A op' B) op (A op' D)" or, in the + // commutative case, "(A op' B) op (C op' A)"? + if (A == C || (InnerCommutative && A == D)) { + if (A != C) + std::swap(C, D); + // Consider forming "A op' (B op D)". + // If "B op D" simplifies then it can be formed with no cost. + Value *V = SimplifyBinOp(TopLevelOpcode, B, D, DL); + // If "B op D" doesn't simplify then only go on if both of the existing + // operations "A op' B" and "C op' D" will be zapped as no longer used. + if (!V && LHS->hasOneUse() && RHS->hasOneUse()) + V = Builder->CreateBinOp(TopLevelOpcode, B, D, RHS->getName()); + if (V) { + SimplifiedInst = Builder->CreateBinOp(InnerOpcode, A, V); + } + } + + // Does "(X op Y) op' Z" always equal "(X op' Z) op (Y op' Z)"? + if (!SimplifiedInst && RightDistributesOverLeft(TopLevelOpcode, InnerOpcode)) + // Does the instruction have the form "(A op' B) op (C op' B)" or, in the + // commutative case, "(A op' B) op (B op' D)"? + if (B == D || (InnerCommutative && B == C)) { + if (B != D) + std::swap(C, D); + // Consider forming "(A op C) op' B". + // If "A op C" simplifies then it can be formed with no cost. + Value *V = SimplifyBinOp(TopLevelOpcode, A, C, DL); + + // If "A op C" doesn't simplify then only go on if both of the existing + // operations "A op' B" and "C op' D" will be zapped as no longer used. + if (!V && LHS->hasOneUse() && RHS->hasOneUse()) + V = Builder->CreateBinOp(TopLevelOpcode, A, C, LHS->getName()); + if (V) { + SimplifiedInst = Builder->CreateBinOp(InnerOpcode, V, B); + } + } + + if (SimplifiedInst) { + ++NumFactor; + SimplifiedInst->takeName(&I); + + // Check if we can add NSW flag to SimplifiedInst. If so, set NSW flag. + // TODO: Check for NUW. + if (BinaryOperator *BO = dyn_cast<BinaryOperator>(SimplifiedInst)) { + if (isa<OverflowingBinaryOperator>(SimplifiedInst)) { + bool HasNSW = false; + if (isa<OverflowingBinaryOperator>(&I)) + HasNSW = I.hasNoSignedWrap(); + + if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS)) + if (isa<OverflowingBinaryOperator>(Op0)) + HasNSW &= Op0->hasNoSignedWrap(); + + if (BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS)) + if (isa<OverflowingBinaryOperator>(Op1)) + HasNSW &= Op1->hasNoSignedWrap(); + BO->setHasNoSignedWrap(HasNSW); + } + } + } + return SimplifiedInst; +} + /// SimplifyUsingDistributiveLaws - This tries to simplify binary operations /// which some other binary operation distributes over either by factorizing /// out common terms (eg "(A*B)+(A*C)" -> "A*(B+C)") or expanding out if this @@ -397,65 +526,33 @@ Value *InstCombiner::SimplifyUsingDistributiveLaws(BinaryOperator &I) { Value *LHS = I.getOperand(0), *RHS = I.getOperand(1); BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS); BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS); - Instruction::BinaryOps TopLevelOpcode = I.getOpcode(); // op // Factorization. - if (Op0 && Op1 && Op0->getOpcode() == Op1->getOpcode()) { - // The instruction has the form "(A op' B) op (C op' D)". Try to factorize - // a common term. - Value *A = Op0->getOperand(0), *B = Op0->getOperand(1); - Value *C = Op1->getOperand(0), *D = Op1->getOperand(1); - Instruction::BinaryOps InnerOpcode = Op0->getOpcode(); // op' + Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr; + Instruction::BinaryOps LHSOpcode = getBinOpsForFactorization(Op0, A, B); + Instruction::BinaryOps RHSOpcode = getBinOpsForFactorization(Op1, C, D); + + // The instruction has the form "(A op' B) op (C op' D)". Try to factorize + // a common term. + if (LHSOpcode == RHSOpcode) { + if (Value *V = tryFactorization(Builder, DL, I, LHSOpcode, A, B, C, D)) + return V; + } - // Does "X op' Y" always equal "Y op' X"? - bool InnerCommutative = Instruction::isCommutative(InnerOpcode); - - // Does "X op' (Y op Z)" always equal "(X op' Y) op (X op' Z)"? - if (LeftDistributesOverRight(InnerOpcode, TopLevelOpcode)) - // Does the instruction have the form "(A op' B) op (A op' D)" or, in the - // commutative case, "(A op' B) op (C op' A)"? - if (A == C || (InnerCommutative && A == D)) { - if (A != C) - std::swap(C, D); - // Consider forming "A op' (B op D)". - // If "B op D" simplifies then it can be formed with no cost. - Value *V = SimplifyBinOp(TopLevelOpcode, B, D, TD); - // If "B op D" doesn't simplify then only go on if both of the existing - // operations "A op' B" and "C op' D" will be zapped as no longer used. - if (!V && Op0->hasOneUse() && Op1->hasOneUse()) - V = Builder->CreateBinOp(TopLevelOpcode, B, D, Op1->getName()); - if (V) { - ++NumFactor; - V = Builder->CreateBinOp(InnerOpcode, A, V); - V->takeName(&I); - return V; - } - } + // The instruction has the form "(A op' B) op (C)". Try to factorize common + // term. + if (Value *V = tryFactorization(Builder, DL, I, LHSOpcode, A, B, RHS, + getIdentityValue(LHSOpcode, RHS))) + return V; - // Does "(X op Y) op' Z" always equal "(X op' Z) op (Y op' Z)"? - if (RightDistributesOverLeft(TopLevelOpcode, InnerOpcode)) - // Does the instruction have the form "(A op' B) op (C op' B)" or, in the - // commutative case, "(A op' B) op (B op' D)"? - if (B == D || (InnerCommutative && B == C)) { - if (B != D) - std::swap(C, D); - // Consider forming "(A op C) op' B". - // If "A op C" simplifies then it can be formed with no cost. - Value *V = SimplifyBinOp(TopLevelOpcode, A, C, TD); - // If "A op C" doesn't simplify then only go on if both of the existing - // operations "A op' B" and "C op' D" will be zapped as no longer used. - if (!V && Op0->hasOneUse() && Op1->hasOneUse()) - V = Builder->CreateBinOp(TopLevelOpcode, A, C, Op0->getName()); - if (V) { - ++NumFactor; - V = Builder->CreateBinOp(InnerOpcode, V, B); - V->takeName(&I); - return V; - } - } - } + // The instruction has the form "(B) op (C op' D)". Try to factorize common + // term. + if (Value *V = tryFactorization(Builder, DL, I, RHSOpcode, LHS, + getIdentityValue(RHSOpcode, LHS), C, D)) + return V; // Expansion. + Instruction::BinaryOps TopLevelOpcode = I.getOpcode(); if (Op0 && RightDistributesOverLeft(Op0->getOpcode(), TopLevelOpcode)) { // The instruction has the form "(A op' B) op C". See if expanding it out // to "(A op C) op' (B op C)" results in simplifications. @@ -463,8 +560,8 @@ Value *InstCombiner::SimplifyUsingDistributiveLaws(BinaryOperator &I) { Instruction::BinaryOps InnerOpcode = Op0->getOpcode(); // op' // Do "A op C" and "B op C" both simplify? - if (Value *L = SimplifyBinOp(TopLevelOpcode, A, C, TD)) - if (Value *R = SimplifyBinOp(TopLevelOpcode, B, C, TD)) { + if (Value *L = SimplifyBinOp(TopLevelOpcode, A, C, DL)) + if (Value *R = SimplifyBinOp(TopLevelOpcode, B, C, DL)) { // They do! Return "L op' R". ++NumExpand; // If "L op' R" equals "A op' B" then "L op' R" is just the LHS. @@ -472,7 +569,7 @@ Value *InstCombiner::SimplifyUsingDistributiveLaws(BinaryOperator &I) { (Instruction::isCommutative(InnerOpcode) && L == B && R == A)) return Op0; // Otherwise return "L op' R" if it simplifies. - if (Value *V = SimplifyBinOp(InnerOpcode, L, R, TD)) + if (Value *V = SimplifyBinOp(InnerOpcode, L, R, DL)) return V; // Otherwise, create a new instruction. C = Builder->CreateBinOp(InnerOpcode, L, R); @@ -488,8 +585,8 @@ Value *InstCombiner::SimplifyUsingDistributiveLaws(BinaryOperator &I) { Instruction::BinaryOps InnerOpcode = Op1->getOpcode(); // op' // Do "A op B" and "A op C" both simplify? - if (Value *L = SimplifyBinOp(TopLevelOpcode, A, B, TD)) - if (Value *R = SimplifyBinOp(TopLevelOpcode, A, C, TD)) { + if (Value *L = SimplifyBinOp(TopLevelOpcode, A, B, DL)) + if (Value *R = SimplifyBinOp(TopLevelOpcode, A, C, DL)) { // They do! Return "L op' R". ++NumExpand; // If "L op' R" equals "B op' C" then "L op' R" is just the RHS. @@ -497,7 +594,7 @@ Value *InstCombiner::SimplifyUsingDistributiveLaws(BinaryOperator &I) { (Instruction::isCommutative(InnerOpcode) && L == C && R == B)) return Op1; // Otherwise return "L op' R" if it simplifies. - if (Value *V = SimplifyBinOp(InnerOpcode, L, R, TD)) + if (Value *V = SimplifyBinOp(InnerOpcode, L, R, DL)) return V; // Otherwise, create a new instruction. A = Builder->CreateBinOp(InnerOpcode, L, R); @@ -506,7 +603,7 @@ Value *InstCombiner::SimplifyUsingDistributiveLaws(BinaryOperator &I) { } } - return 0; + return nullptr; } // dyn_castNegVal - Given a 'sub' instruction, return the RHS of the instruction @@ -524,7 +621,7 @@ Value *InstCombiner::dyn_castNegVal(Value *V) const { if (C->getType()->getElementType()->isIntegerTy()) return ConstantExpr::getNeg(C); - return 0; + return nullptr; } // dyn_castFNegVal - Given a 'fsub' instruction, return the RHS of the @@ -543,7 +640,7 @@ Value *InstCombiner::dyn_castFNegVal(Value *V, bool IgnoreZeroSign) const { if (C->getType()->getElementType()->isFloatingPointTy()) return ConstantExpr::getFNeg(C); - return 0; + return nullptr; } static Value *FoldOperationIntoSelectOperand(Instruction &I, Value *SO, @@ -566,9 +663,14 @@ static Value *FoldOperationIntoSelectOperand(Instruction &I, Value *SO, if (!ConstIsRHS) std::swap(Op0, Op1); - if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&I)) - return IC->Builder->CreateBinOp(BO->getOpcode(), Op0, Op1, + if (BinaryOperator *BO = dyn_cast<BinaryOperator>(&I)) { + Value *RI = IC->Builder->CreateBinOp(BO->getOpcode(), Op0, Op1, SO->getName()+".op"); + Instruction *FPInst = dyn_cast<Instruction>(RI); + if (FPInst && isa<FPMathOperator>(FPInst)) + FPInst->copyFastMathFlags(BO); + return RI; + } if (ICmpInst *CI = dyn_cast<ICmpInst>(&I)) return IC->Builder->CreateICmp(CI->getPredicate(), Op0, Op1, SO->getName()+".cmp"); @@ -584,13 +686,13 @@ static Value *FoldOperationIntoSelectOperand(Instruction &I, Value *SO, // not have a second operand. Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { // Don't modify shared select instructions - if (!SI->hasOneUse()) return 0; + if (!SI->hasOneUse()) return nullptr; Value *TV = SI->getOperand(1); Value *FV = SI->getOperand(2); if (isa<Constant>(TV) || isa<Constant>(FV)) { // Bool selects with constant operands can be folded to logical ops. - if (SI->getType()->isIntegerTy(1)) return 0; + if (SI->getType()->isIntegerTy(1)) return nullptr; // If it's a bitcast involving vectors, make sure it has the same number of // elements on both sides. @@ -599,10 +701,10 @@ Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { VectorType *SrcTy = dyn_cast<VectorType>(BC->getSrcTy()); // Verify that either both or neither are vectors. - if ((SrcTy == NULL) != (DestTy == NULL)) return 0; + if ((SrcTy == nullptr) != (DestTy == nullptr)) return nullptr; // If vectors, verify that they have the same number of elements. if (SrcTy && SrcTy->getNumElements() != DestTy->getNumElements()) - return 0; + return nullptr; } Value *SelectTrueVal = FoldOperationIntoSelectOperand(Op, TV, this); @@ -611,7 +713,7 @@ Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) { return SelectInst::Create(SI->getCondition(), SelectTrueVal, SelectFalseVal); } - return 0; + return nullptr; } @@ -623,18 +725,17 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { PHINode *PN = cast<PHINode>(I.getOperand(0)); unsigned NumPHIValues = PN->getNumIncomingValues(); if (NumPHIValues == 0) - return 0; + return nullptr; // We normally only transform phis with a single use. However, if a PHI has // multiple uses and they are all the same operation, we can fold *all* of the // uses into the PHI. if (!PN->hasOneUse()) { // Walk the use list for the instruction, comparing them to I. - for (Value::use_iterator UI = PN->use_begin(), E = PN->use_end(); - UI != E; ++UI) { - Instruction *User = cast<Instruction>(*UI); - if (User != &I && !I.isIdenticalTo(User)) - return 0; + for (User *U : PN->users()) { + Instruction *UI = cast<Instruction>(U); + if (UI != &I && !I.isIdenticalTo(UI)) + return nullptr; } // Otherwise, we can replace *all* users with the new PHI we form. } @@ -644,14 +745,14 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { // remember the BB it is in. If there is more than one or if *it* is a PHI, // bail out. We don't do arbitrary constant expressions here because moving // their computation can be expensive without a cost model. - BasicBlock *NonConstBB = 0; + BasicBlock *NonConstBB = nullptr; for (unsigned i = 0; i != NumPHIValues; ++i) { Value *InVal = PN->getIncomingValue(i); if (isa<Constant>(InVal) && !isa<ConstantExpr>(InVal)) continue; - if (isa<PHINode>(InVal)) return 0; // Itself a phi. - if (NonConstBB) return 0; // More than one non-const value. + if (isa<PHINode>(InVal)) return nullptr; // Itself a phi. + if (NonConstBB) return nullptr; // More than one non-const value. NonConstBB = PN->getIncomingBlock(i); @@ -659,22 +760,22 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { // insert a computation after it without breaking the edge. if (InvokeInst *II = dyn_cast<InvokeInst>(InVal)) if (II->getParent() == NonConstBB) - return 0; + return nullptr; // If the incoming non-constant value is in I's block, we will remove one // instruction, but insert another equivalent one, leading to infinite // instcombine. if (NonConstBB == I.getParent()) - return 0; + return nullptr; } // If there is exactly one non-constant value, we can insert a copy of the // operation in that block. However, if this is a critical edge, we would be // inserting the computation one some other paths (e.g. inside a loop). Only // do this if the pred block is unconditionally branching into the phi block. - if (NonConstBB != 0) { + if (NonConstBB != nullptr) { BranchInst *BI = dyn_cast<BranchInst>(NonConstBB->getTerminator()); - if (!BI || !BI->isUnconditional()) return 0; + if (!BI || !BI->isUnconditional()) return nullptr; } // Okay, we can do the transformation: create the new PHI node. @@ -698,7 +799,7 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { BasicBlock *ThisBB = PN->getIncomingBlock(i); Value *TrueVInPred = TrueV->DoPHITranslation(PhiTransBB, ThisBB); Value *FalseVInPred = FalseV->DoPHITranslation(PhiTransBB, ThisBB); - Value *InV = 0; + Value *InV = nullptr; // Beware of ConstantExpr: it may eventually evaluate to getNullValue, // even if currently isNullValue gives false. Constant *InC = dyn_cast<Constant>(PN->getIncomingValue(i)); @@ -712,7 +813,7 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { } else if (CmpInst *CI = dyn_cast<CmpInst>(&I)) { Constant *C = cast<Constant>(I.getOperand(1)); for (unsigned i = 0; i != NumPHIValues; ++i) { - Value *InV = 0; + Value *InV = nullptr; if (Constant *InC = dyn_cast<Constant>(PN->getIncomingValue(i))) InV = ConstantExpr::getCompare(CI->getPredicate(), InC, C); else if (isa<ICmpInst>(CI)) @@ -726,7 +827,7 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { } else if (I.getNumOperands() == 2) { Constant *C = cast<Constant>(I.getOperand(1)); for (unsigned i = 0; i != NumPHIValues; ++i) { - Value *InV = 0; + Value *InV = nullptr; if (Constant *InC = dyn_cast<Constant>(PN->getIncomingValue(i))) InV = ConstantExpr::get(I.getOpcode(), InC, C); else @@ -748,8 +849,7 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { } } - for (Value::use_iterator UI = PN->use_begin(), E = PN->use_end(); - UI != E; ) { + for (auto UI = PN->user_begin(), E = PN->user_end(); UI != E;) { Instruction *User = cast<Instruction>(*UI++); if (User == &I) continue; ReplaceInstUsesWith(*User, NewPN); @@ -766,19 +866,19 @@ Type *InstCombiner::FindElementAtOffset(Type *PtrTy, int64_t Offset, SmallVectorImpl<Value*> &NewIndices) { assert(PtrTy->isPtrOrPtrVectorTy()); - if (!TD) - return 0; + if (!DL) + return nullptr; Type *Ty = PtrTy->getPointerElementType(); if (!Ty->isSized()) - return 0; + return nullptr; // Start with the index over the outer type. Note that the type size // might be zero (even if the offset isn't zero) if the indexed type // is something like [0 x {int, int}] - Type *IntPtrTy = TD->getIntPtrType(PtrTy); + Type *IntPtrTy = DL->getIntPtrType(PtrTy); int64_t FirstIdx = 0; - if (int64_t TySize = TD->getTypeAllocSize(Ty)) { + if (int64_t TySize = DL->getTypeAllocSize(Ty)) { FirstIdx = Offset/TySize; Offset -= FirstIdx*TySize; @@ -796,11 +896,11 @@ Type *InstCombiner::FindElementAtOffset(Type *PtrTy, int64_t Offset, // Index into the types. If we fail, set OrigBase to null. while (Offset) { // Indexing into tail padding between struct/array elements. - if (uint64_t(Offset*8) >= TD->getTypeSizeInBits(Ty)) - return 0; + if (uint64_t(Offset*8) >= DL->getTypeSizeInBits(Ty)) + return nullptr; if (StructType *STy = dyn_cast<StructType>(Ty)) { - const StructLayout *SL = TD->getStructLayout(STy); + const StructLayout *SL = DL->getStructLayout(STy); assert(Offset < (int64_t)SL->getSizeInBytes() && "Offset must stay within the indexed type"); @@ -811,14 +911,14 @@ Type *InstCombiner::FindElementAtOffset(Type *PtrTy, int64_t Offset, Offset -= SL->getElementOffset(Elt); Ty = STy->getElementType(Elt); } else if (ArrayType *AT = dyn_cast<ArrayType>(Ty)) { - uint64_t EltSize = TD->getTypeAllocSize(AT->getElementType()); + uint64_t EltSize = DL->getTypeAllocSize(AT->getElementType()); assert(EltSize && "Cannot index into a zero-sized array"); NewIndices.push_back(ConstantInt::get(IntPtrTy,Offset/EltSize)); Offset %= EltSize; Ty = AT->getElementType(); } else { // Otherwise, we can't index into the middle of this atomic type, bail. - return 0; + return nullptr; } } @@ -850,7 +950,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { // If Scale is zero then it does not divide Val. if (Scale.isMinValue()) - return 0; + return nullptr; // Look through chains of multiplications, searching for a constant that is // divisible by Scale. For example, descaling X*(Y*(Z*4)) by a factor of 4 @@ -893,7 +993,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { APInt::sdivrem(CI->getValue(), Scale, Quotient, Remainder); if (!Remainder.isMinValue()) // Not divisible by Scale. - return 0; + return nullptr; // Replace with the quotient in the parent. Op = ConstantInt::get(CI->getType(), Quotient); NoSignedWrap = true; @@ -906,7 +1006,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { // Multiplication. NoSignedWrap = BO->hasNoSignedWrap(); if (RequireNoSignedWrap && !NoSignedWrap) - return 0; + return nullptr; // There are three cases for multiplication: multiplication by exactly // the scale, multiplication by a constant different to the scale, and @@ -925,7 +1025,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { // Otherwise drill down into the constant. if (!Op->hasOneUse()) - return 0; + return nullptr; Parent = std::make_pair(BO, 1); continue; @@ -934,7 +1034,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { // Multiplication by something else. Drill down into the left-hand side // since that's where the reassociate pass puts the good stuff. if (!Op->hasOneUse()) - return 0; + return nullptr; Parent = std::make_pair(BO, 0); continue; @@ -945,7 +1045,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { // Multiplication by a power of 2. NoSignedWrap = BO->hasNoSignedWrap(); if (RequireNoSignedWrap && !NoSignedWrap) - return 0; + return nullptr; Value *LHS = BO->getOperand(0); int32_t Amt = cast<ConstantInt>(BO->getOperand(1))-> @@ -959,7 +1059,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { break; } if (Amt < logScale || !Op->hasOneUse()) - return 0; + return nullptr; // Multiplication by more than the scale. Reduce the multiplying amount // by the scale in the parent. @@ -970,7 +1070,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { } if (!Op->hasOneUse()) - return 0; + return nullptr; if (CastInst *Cast = dyn_cast<CastInst>(Op)) { if (Cast->getOpcode() == Instruction::SExt) { @@ -984,7 +1084,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { // Scale and the multiplication Y * SmallScale should not overflow. if (SmallScale.sext(Scale.getBitWidth()) != Scale) // SmallScale does not sign-extend to Scale. - return 0; + return nullptr; assert(SmallScale.exactLogBase2() == logScale); // Require that Y * SmallScale must not overflow. RequireNoSignedWrap = true; @@ -1003,7 +1103,7 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { // trunc (Y * sext Scale) does not, so nsw flags need to be cleared // from this point up in the expression (see later). if (RequireNoSignedWrap) - return 0; + return nullptr; // Drill down through the cast. unsigned LargeSize = Cast->getSrcTy()->getPrimitiveSizeInBits(); @@ -1017,7 +1117,13 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { } // Unsupported expression, bail out. - return 0; + return nullptr; + } + + // If Op is zero then Val = Op * Scale. + if (match(Op, m_Zero())) { + NoSignedWrap = true; + return Op; } // We know that we can successfully descale, so from here on we can safely @@ -1069,23 +1175,125 @@ Value *InstCombiner::Descale(Value *Val, APInt Scale, bool &NoSignedWrap) { // Move up one level in the expression. assert(Ancestor->hasOneUse() && "Drilled down when more than one use!"); - Ancestor = Ancestor->use_back(); + Ancestor = Ancestor->user_back(); } while (1); } +/// \brief Creates node of binary operation with the same attributes as the +/// specified one but with other operands. +static Value *CreateBinOpAsGiven(BinaryOperator &Inst, Value *LHS, Value *RHS, + InstCombiner::BuilderTy *B) { + Value *BORes = B->CreateBinOp(Inst.getOpcode(), LHS, RHS); + if (BinaryOperator *NewBO = dyn_cast<BinaryOperator>(BORes)) { + if (isa<OverflowingBinaryOperator>(NewBO)) { + NewBO->setHasNoSignedWrap(Inst.hasNoSignedWrap()); + NewBO->setHasNoUnsignedWrap(Inst.hasNoUnsignedWrap()); + } + if (isa<PossiblyExactOperator>(NewBO)) + NewBO->setIsExact(Inst.isExact()); + } + return BORes; +} + +/// \brief Makes transformation of binary operation specific for vector types. +/// \param Inst Binary operator to transform. +/// \return Pointer to node that must replace the original binary operator, or +/// null pointer if no transformation was made. +Value *InstCombiner::SimplifyVectorOp(BinaryOperator &Inst) { + if (!Inst.getType()->isVectorTy()) return nullptr; + + // It may not be safe to reorder shuffles and things like div, urem, etc. + // because we may trap when executing those ops on unknown vector elements. + // See PR20059. + if (!isSafeToSpeculativelyExecute(&Inst, DL)) return nullptr; + + unsigned VWidth = cast<VectorType>(Inst.getType())->getNumElements(); + Value *LHS = Inst.getOperand(0), *RHS = Inst.getOperand(1); + assert(cast<VectorType>(LHS->getType())->getNumElements() == VWidth); + assert(cast<VectorType>(RHS->getType())->getNumElements() == VWidth); + + // If both arguments of binary operation are shuffles, which use the same + // mask and shuffle within a single vector, it is worthwhile to move the + // shuffle after binary operation: + // Op(shuffle(v1, m), shuffle(v2, m)) -> shuffle(Op(v1, v2), m) + if (isa<ShuffleVectorInst>(LHS) && isa<ShuffleVectorInst>(RHS)) { + ShuffleVectorInst *LShuf = cast<ShuffleVectorInst>(LHS); + ShuffleVectorInst *RShuf = cast<ShuffleVectorInst>(RHS); + if (isa<UndefValue>(LShuf->getOperand(1)) && + isa<UndefValue>(RShuf->getOperand(1)) && + LShuf->getOperand(0)->getType() == RShuf->getOperand(0)->getType() && + LShuf->getMask() == RShuf->getMask()) { + Value *NewBO = CreateBinOpAsGiven(Inst, LShuf->getOperand(0), + RShuf->getOperand(0), Builder); + Value *Res = Builder->CreateShuffleVector(NewBO, + UndefValue::get(NewBO->getType()), LShuf->getMask()); + return Res; + } + } + + // If one argument is a shuffle within one vector, the other is a constant, + // try moving the shuffle after the binary operation. + ShuffleVectorInst *Shuffle = nullptr; + Constant *C1 = nullptr; + if (isa<ShuffleVectorInst>(LHS)) Shuffle = cast<ShuffleVectorInst>(LHS); + if (isa<ShuffleVectorInst>(RHS)) Shuffle = cast<ShuffleVectorInst>(RHS); + if (isa<Constant>(LHS)) C1 = cast<Constant>(LHS); + if (isa<Constant>(RHS)) C1 = cast<Constant>(RHS); + if (Shuffle && C1 && + (isa<ConstantVector>(C1) || isa<ConstantDataVector>(C1)) && + isa<UndefValue>(Shuffle->getOperand(1)) && + Shuffle->getType() == Shuffle->getOperand(0)->getType()) { + SmallVector<int, 16> ShMask = Shuffle->getShuffleMask(); + // Find constant C2 that has property: + // shuffle(C2, ShMask) = C1 + // If such constant does not exist (example: ShMask=<0,0> and C1=<1,2>) + // reorder is not possible. + SmallVector<Constant*, 16> C2M(VWidth, + UndefValue::get(C1->getType()->getScalarType())); + bool MayChange = true; + for (unsigned I = 0; I < VWidth; ++I) { + if (ShMask[I] >= 0) { + assert(ShMask[I] < (int)VWidth); + if (!isa<UndefValue>(C2M[ShMask[I]])) { + MayChange = false; + break; + } + C2M[ShMask[I]] = C1->getAggregateElement(I); + } + } + if (MayChange) { + Constant *C2 = ConstantVector::get(C2M); + Value *NewLHS, *NewRHS; + if (isa<Constant>(LHS)) { + NewLHS = C2; + NewRHS = Shuffle->getOperand(0); + } else { + NewLHS = Shuffle->getOperand(0); + NewRHS = C2; + } + Value *NewBO = CreateBinOpAsGiven(Inst, NewLHS, NewRHS, Builder); + Value *Res = Builder->CreateShuffleVector(NewBO, + UndefValue::get(Inst.getType()), Shuffle->getMask()); + return Res; + } + } + + return nullptr; +} + Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { SmallVector<Value*, 8> Ops(GEP.op_begin(), GEP.op_end()); - if (Value *V = SimplifyGEPInst(Ops, TD)) + if (Value *V = SimplifyGEPInst(Ops, DL)) return ReplaceInstUsesWith(GEP, V); Value *PtrOp = GEP.getOperand(0); // Eliminate unneeded casts for indices, and replace indices which displace // by multiples of a zero size type with zero. - if (TD) { + if (DL) { bool MadeChange = false; - Type *IntPtrTy = TD->getIntPtrType(GEP.getPointerOperandType()); + Type *IntPtrTy = DL->getIntPtrType(GEP.getPointerOperandType()); gep_type_iterator GTI = gep_type_begin(GEP); for (User::op_iterator I = GEP.op_begin() + 1, E = GEP.op_end(); @@ -1097,7 +1305,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // If the element type has zero size then any index over it is equivalent // to an index of zero, so replace it with zero if it is not zero already. if (SeqTy->getElementType()->isSized() && - TD->getTypeAllocSize(SeqTy->getElementType()) == 0) + DL->getTypeAllocSize(SeqTy->getElementType()) == 0) if (!isa<Constant>(*I) || !cast<Constant>(*I)->isNullValue()) { *I = Constant::getNullValue(IntPtrTy); MadeChange = true; @@ -1115,13 +1323,98 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { if (MadeChange) return &GEP; } + // Check to see if the inputs to the PHI node are getelementptr instructions. + if (PHINode *PN = dyn_cast<PHINode>(PtrOp)) { + GetElementPtrInst *Op1 = dyn_cast<GetElementPtrInst>(PN->getOperand(0)); + if (!Op1) + return nullptr; + + signed DI = -1; + + for (auto I = PN->op_begin()+1, E = PN->op_end(); I !=E; ++I) { + GetElementPtrInst *Op2 = dyn_cast<GetElementPtrInst>(*I); + if (!Op2 || Op1->getNumOperands() != Op2->getNumOperands()) + return nullptr; + + // Keep track of the type as we walk the GEP. + Type *CurTy = Op1->getOperand(0)->getType()->getScalarType(); + + for (unsigned J = 0, F = Op1->getNumOperands(); J != F; ++J) { + if (Op1->getOperand(J)->getType() != Op2->getOperand(J)->getType()) + return nullptr; + + if (Op1->getOperand(J) != Op2->getOperand(J)) { + if (DI == -1) { + // We have not seen any differences yet in the GEPs feeding the + // PHI yet, so we record this one if it is allowed to be a + // variable. + + // The first two arguments can vary for any GEP, the rest have to be + // static for struct slots + if (J > 1 && CurTy->isStructTy()) + return nullptr; + + DI = J; + } else { + // The GEP is different by more than one input. While this could be + // extended to support GEPs that vary by more than one variable it + // doesn't make sense since it greatly increases the complexity and + // would result in an R+R+R addressing mode which no backend + // directly supports and would need to be broken into several + // simpler instructions anyway. + return nullptr; + } + } + + // Sink down a layer of the type for the next iteration. + if (J > 0) { + if (CompositeType *CT = dyn_cast<CompositeType>(CurTy)) { + CurTy = CT->getTypeAtIndex(Op1->getOperand(J)); + } else { + CurTy = nullptr; + } + } + } + } + + GetElementPtrInst *NewGEP = cast<GetElementPtrInst>(Op1->clone()); + + if (DI == -1) { + // All the GEPs feeding the PHI are identical. Clone one down into our + // BB so that it can be merged with the current GEP. + GEP.getParent()->getInstList().insert(GEP.getParent()->getFirstNonPHI(), + NewGEP); + } else { + // All the GEPs feeding the PHI differ at a single offset. Clone a GEP + // into the current block so it can be merged, and create a new PHI to + // set that index. + Instruction *InsertPt = Builder->GetInsertPoint(); + Builder->SetInsertPoint(PN); + PHINode *NewPN = Builder->CreatePHI(Op1->getOperand(DI)->getType(), + PN->getNumOperands()); + Builder->SetInsertPoint(InsertPt); + + for (auto &I : PN->operands()) + NewPN->addIncoming(cast<GEPOperator>(I)->getOperand(DI), + PN->getIncomingBlock(I)); + + NewGEP->setOperand(DI, NewPN); + GEP.getParent()->getInstList().insert(GEP.getParent()->getFirstNonPHI(), + NewGEP); + NewGEP->setOperand(DI, NewPN); + } + + GEP.setOperand(0, NewGEP); + PtrOp = NewGEP; + } + // Combine Indices - If the source pointer to this getelementptr instruction // is a getelementptr instruction, combine the indices of the two // getelementptr instructions into a single instruction. // if (GEPOperator *Src = dyn_cast<GEPOperator>(PtrOp)) { if (!shouldMergeGEPs(*cast<GEPOperator>(&GEP), *Src)) - return 0; + return nullptr; // Note that if our source is a gep chain itself then we wait for that // chain to be resolved before we perform this transformation. This @@ -1129,7 +1422,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { if (GEPOperator *SrcGEP = dyn_cast<GEPOperator>(Src->getOperand(0))) if (SrcGEP->getNumOperands() == 2 && shouldMergeGEPs(*Src, *SrcGEP)) - return 0; // Wait until our source is folded to completion. + return nullptr; // Wait until our source is folded to completion. SmallVector<Value*, 8> Indices; @@ -1157,7 +1450,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // intptr_t). Just avoid transforming this until the input has been // normalized. if (SO1->getType() != GO1->getType()) - return 0; + return nullptr; Sum = Builder->CreateAdd(SO1, GO1, PtrOp->getName()+".sum"); } @@ -1188,12 +1481,12 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // Canonicalize (gep i8* X, -(ptrtoint Y)) to (sub (ptrtoint X), (ptrtoint Y)) // The GEP pattern is emitted by the SCEV expander for certain kinds of // pointer arithmetic. - if (TD && GEP.getNumIndices() == 1 && + if (DL && GEP.getNumIndices() == 1 && match(GEP.getOperand(1), m_Neg(m_PtrToInt(m_Value())))) { unsigned AS = GEP.getPointerAddressSpace(); if (GEP.getType() == Builder->getInt8PtrTy(AS) && GEP.getOperand(1)->getType()->getScalarSizeInBits() == - TD->getPointerSizeInBits(AS)) { + DL->getPointerSizeInBits(AS)) { Operator *Index = cast<Operator>(GEP.getOperand(1)); Value *PtrToInt = Builder->CreatePtrToInt(PtrOp, Index->getType()); Value *NewSub = Builder->CreateSub(PtrToInt, Index->getOperand(1)); @@ -1207,11 +1500,9 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // We do not handle pointer-vector geps here. if (!StrippedPtrTy) - return 0; - - if (StrippedPtr != PtrOp && - StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace()) { + return nullptr; + if (StrippedPtr != PtrOp) { bool HasZeroPointerIndex = false; if (ConstantInt *C = dyn_cast<ConstantInt>(GEP.getOperand(1))) HasZeroPointerIndex = C->isZero(); @@ -1234,7 +1525,15 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { GetElementPtrInst *Res = GetElementPtrInst::Create(StrippedPtr, Idx, GEP.getName()); Res->setIsInBounds(GEP.isInBounds()); - return Res; + if (StrippedPtrTy->getAddressSpace() == GEP.getAddressSpace()) + return Res; + // Insert Res, and create an addrspacecast. + // e.g., + // GEP (addrspacecast i8 addrspace(1)* X to [0 x i8]*), i32 0, ... + // -> + // %0 = GEP i8 addrspace(1)* X, ... + // addrspacecast i8 addrspace(1)* %0 to i8* + return new AddrSpaceCastInst(Builder->Insert(Res), GEP.getType()); } if (ArrayType *XATy = @@ -1246,8 +1545,24 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // to an array of the same type as the destination pointer // array. Because the array type is never stepped over (there // is a leading zero) we can fold the cast into this GEP. - GEP.setOperand(0, StrippedPtr); - return &GEP; + if (StrippedPtrTy->getAddressSpace() == GEP.getAddressSpace()) { + GEP.setOperand(0, StrippedPtr); + return &GEP; + } + // Cannot replace the base pointer directly because StrippedPtr's + // address space is different. Instead, create a new GEP followed by + // an addrspacecast. + // e.g., + // GEP (addrspacecast [10 x i8] addrspace(1)* X to [0 x i8]*), + // i32 0, ... + // -> + // %0 = GEP [10 x i8] addrspace(1)* X, ... + // addrspacecast i8 addrspace(1)* %0 to i8* + SmallVector<Value*, 8> Idx(GEP.idx_begin(), GEP.idx_end()); + Value *NewGEP = GEP.isInBounds() ? + Builder->CreateInBoundsGEP(StrippedPtr, Idx, GEP.getName()) : + Builder->CreateGEP(StrippedPtr, Idx, GEP.getName()); + return new AddrSpaceCastInst(NewGEP, GEP.getType()); } } } @@ -1257,27 +1572,29 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // into: %t1 = getelementptr [2 x i32]* %str, i32 0, i32 %V; bitcast Type *SrcElTy = StrippedPtrTy->getElementType(); Type *ResElTy = PtrOp->getType()->getPointerElementType(); - if (TD && SrcElTy->isArrayTy() && - TD->getTypeAllocSize(SrcElTy->getArrayElementType()) == - TD->getTypeAllocSize(ResElTy)) { - Type *IdxType = TD->getIntPtrType(GEP.getType()); + if (DL && SrcElTy->isArrayTy() && + DL->getTypeAllocSize(SrcElTy->getArrayElementType()) == + DL->getTypeAllocSize(ResElTy)) { + Type *IdxType = DL->getIntPtrType(GEP.getType()); Value *Idx[2] = { Constant::getNullValue(IdxType), GEP.getOperand(1) }; Value *NewGEP = GEP.isInBounds() ? Builder->CreateInBoundsGEP(StrippedPtr, Idx, GEP.getName()) : Builder->CreateGEP(StrippedPtr, Idx, GEP.getName()); + // V and GEP are both pointer types --> BitCast - return new BitCastInst(NewGEP, GEP.getType()); + return CastInst::CreatePointerBitCastOrAddrSpaceCast(NewGEP, + GEP.getType()); } // Transform things like: // %V = mul i64 %N, 4 // %t = getelementptr i8* bitcast (i32* %arr to i8*), i32 %V // into: %t1 = getelementptr i32* %arr, i32 %N; bitcast - if (TD && ResElTy->isSized() && SrcElTy->isSized()) { + if (DL && ResElTy->isSized() && SrcElTy->isSized()) { // Check that changing the type amounts to dividing the index by a scale // factor. - uint64_t ResSize = TD->getTypeAllocSize(ResElTy); - uint64_t SrcSize = TD->getTypeAllocSize(SrcElTy); + uint64_t ResSize = DL->getTypeAllocSize(ResElTy); + uint64_t SrcSize = DL->getTypeAllocSize(SrcElTy); if (ResSize && SrcSize % ResSize == 0) { Value *Idx = GEP.getOperand(1); unsigned BitWidth = Idx->getType()->getPrimitiveSizeInBits(); @@ -1285,7 +1602,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // Earlier transforms ensure that the index has type IntPtrType, which // considerably simplifies the logic by eliminating implicit casts. - assert(Idx->getType() == TD->getIntPtrType(GEP.getType()) && + assert(Idx->getType() == DL->getIntPtrType(GEP.getType()) && "Index not cast to pointer width?"); bool NSW; @@ -1296,8 +1613,10 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { Value *NewGEP = GEP.isInBounds() && NSW ? Builder->CreateInBoundsGEP(StrippedPtr, NewIdx, GEP.getName()) : Builder->CreateGEP(StrippedPtr, NewIdx, GEP.getName()); + // The NewGEP must be pointer typed, so must the old one -> BitCast - return new BitCastInst(NewGEP, GEP.getType()); + return CastInst::CreatePointerBitCastOrAddrSpaceCast(NewGEP, + GEP.getType()); } } } @@ -1306,13 +1625,13 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // getelementptr i8* bitcast ([100 x double]* X to i8*), i32 %tmp // (where tmp = 8*tmp2) into: // getelementptr [100 x double]* %arr, i32 0, i32 %tmp2; bitcast - if (TD && ResElTy->isSized() && SrcElTy->isSized() && + if (DL && ResElTy->isSized() && SrcElTy->isSized() && SrcElTy->isArrayTy()) { // Check that changing to the array element type amounts to dividing the // index by a scale factor. - uint64_t ResSize = TD->getTypeAllocSize(ResElTy); + uint64_t ResSize = DL->getTypeAllocSize(ResElTy); uint64_t ArrayEltSize - = TD->getTypeAllocSize(SrcElTy->getArrayElementType()); + = DL->getTypeAllocSize(SrcElTy->getArrayElementType()); if (ResSize && ArrayEltSize % ResSize == 0) { Value *Idx = GEP.getOperand(1); unsigned BitWidth = Idx->getType()->getPrimitiveSizeInBits(); @@ -1320,7 +1639,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // Earlier transforms ensure that the index has type IntPtrType, which // considerably simplifies the logic by eliminating implicit casts. - assert(Idx->getType() == TD->getIntPtrType(GEP.getType()) && + assert(Idx->getType() == DL->getIntPtrType(GEP.getType()) && "Index not cast to pointer width?"); bool NSW; @@ -1329,7 +1648,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { // If the multiplication NewIdx * Scale may overflow then the new // GEP may not be "inbounds". Value *Off[2] = { - Constant::getNullValue(TD->getIntPtrType(GEP.getType())), + Constant::getNullValue(DL->getIntPtrType(GEP.getType())), NewIdx }; @@ -1337,15 +1656,16 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { Builder->CreateInBoundsGEP(StrippedPtr, Off, GEP.getName()) : Builder->CreateGEP(StrippedPtr, Off, GEP.getName()); // The NewGEP must be pointer typed, so must the old one -> BitCast - return new BitCastInst(NewGEP, GEP.getType()); + return CastInst::CreatePointerBitCastOrAddrSpaceCast(NewGEP, + GEP.getType()); } } } } } - if (!TD) - return 0; + if (!DL) + return nullptr; /// See if we can simplify: /// X = bitcast A* to B* @@ -1355,10 +1675,10 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { if (BitCastInst *BCI = dyn_cast<BitCastInst>(PtrOp)) { Value *Operand = BCI->getOperand(0); PointerType *OpType = cast<PointerType>(Operand->getType()); - unsigned OffsetBits = TD->getPointerTypeSizeInBits(OpType); + unsigned OffsetBits = DL->getPointerTypeSizeInBits(OpType); APInt Offset(OffsetBits, 0); if (!isa<BitCastInst>(Operand) && - GEP.accumulateConstantOffset(*TD, Offset) && + GEP.accumulateConstantOffset(*DL, Offset) && StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace()) { // If this GEP instruction doesn't move the pointer, just replace the GEP @@ -1397,7 +1717,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { } } - return 0; + return nullptr; } static bool @@ -1408,9 +1728,8 @@ isAllocSiteRemovable(Instruction *AI, SmallVectorImpl<WeakVH> &Users, do { Instruction *PI = Worklist.pop_back_val(); - for (Value::use_iterator UI = PI->use_begin(), UE = PI->use_end(); UI != UE; - ++UI) { - Instruction *I = cast<Instruction>(*UI); + for (User *U : PI->users()) { + Instruction *I = cast<Instruction>(U); switch (I->getOpcode()) { default: // Give up the moment we see something we can't handle. @@ -1513,7 +1832,7 @@ Instruction *InstCombiner::visitAllocSite(Instruction &MI) { } return EraseInstFromFunction(MI); } - return 0; + return nullptr; } /// \brief Move the call to free before a NULL test. @@ -1542,30 +1861,30 @@ tryToMoveFreeBeforeNullTest(CallInst &FI) { // would duplicate the call to free in each predecessor and it may // not be profitable even for code size. if (!PredBB) - return 0; + return nullptr; // Validate constraint #2: Does this block contains only the call to // free and an unconditional branch? // FIXME: We could check if we can speculate everything in the // predecessor block if (FreeInstrBB->size() != 2) - return 0; + return nullptr; BasicBlock *SuccBB; if (!match(FreeInstrBB->getTerminator(), m_UnconditionalBr(SuccBB))) - return 0; + return nullptr; // Validate the rest of constraint #1 by matching on the pred branch. TerminatorInst *TI = PredBB->getTerminator(); BasicBlock *TrueBB, *FalseBB; ICmpInst::Predicate Pred; if (!match(TI, m_Br(m_ICmp(Pred, m_Specific(Op), m_Zero()), TrueBB, FalseBB))) - return 0; + return nullptr; if (Pred != ICmpInst::ICMP_EQ && Pred != ICmpInst::ICMP_NE) - return 0; + return nullptr; // Validate constraint #3: Ensure the null case just falls through. if (SuccBB != (Pred == ICmpInst::ICMP_EQ ? TrueBB : FalseBB)) - return 0; + return nullptr; assert(FreeInstrBB == (Pred == ICmpInst::ICMP_EQ ? FalseBB : TrueBB) && "Broken CFG: missing edge from predecessor to successor"); @@ -1600,14 +1919,14 @@ Instruction *InstCombiner::visitFree(CallInst &FI) { if (Instruction *I = tryToMoveFreeBeforeNullTest(FI)) return I; - return 0; + return nullptr; } Instruction *InstCombiner::visitBranchInst(BranchInst &BI) { // Change br (not X), label True, label False to: br X, label False, True - Value *X = 0; + Value *X = nullptr; BasicBlock *TrueDest; BasicBlock *FalseDest; if (match(&BI, m_Br(m_Not(m_Value(X)), TrueDest, FalseDest)) && @@ -1618,7 +1937,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) { return &BI; } - // Cannonicalize fcmp_one -> fcmp_oeq + // Canonicalize fcmp_one -> fcmp_oeq FCmpInst::Predicate FPred; Value *Y; if (match(&BI, m_Br(m_FCmp(FPred, m_Value(X), m_Value(Y)), TrueDest, FalseDest)) && @@ -1634,7 +1953,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) { return &BI; } - // Cannonicalize icmp_ne -> icmp_eq + // Canonicalize icmp_ne -> icmp_eq ICmpInst::Predicate IPred; if (match(&BI, m_Br(m_ICmp(IPred, m_Value(X), m_Value(Y)), TrueDest, FalseDest)) && @@ -1650,7 +1969,7 @@ Instruction *InstCombiner::visitBranchInst(BranchInst &BI) { return &BI; } - return 0; + return nullptr; } Instruction *InstCombiner::visitSwitchInst(SwitchInst &SI) { @@ -1674,7 +1993,7 @@ Instruction *InstCombiner::visitSwitchInst(SwitchInst &SI) { return &SI; } } - return 0; + return nullptr; } Instruction *InstCombiner::visitExtractValueInst(ExtractValueInst &EV) { @@ -1691,7 +2010,7 @@ Instruction *InstCombiner::visitExtractValueInst(ExtractValueInst &EV) { // first index return ExtractValueInst::Create(C2, EV.getIndices().slice(1)); } - return 0; // Can't handle other constants + return nullptr; // Can't handle other constants } if (InsertValueInst *IV = dyn_cast<InsertValueInst>(Agg)) { @@ -1824,7 +2143,7 @@ Instruction *InstCombiner::visitExtractValueInst(ExtractValueInst &EV) { // and if again single-use then via load (gep (gep)) to load (gep). // However, double extracts from e.g. function arguments or return values // aren't handled yet. - return 0; + return nullptr; } enum Personality_Type { @@ -1880,7 +2199,7 @@ Instruction *InstCombiner::visitLandingPadInst(LandingPadInst &LI) { // Simplify the list of clauses, eg by removing repeated catch clauses // (these are often created by inlining). bool MakeNewInstruction = false; // If true, recreate using the following: - SmallVector<Value *, 16> NewClauses; // - Clauses for the new instruction; + SmallVector<Constant *, 16> NewClauses; // - Clauses for the new instruction; bool CleanupFlag = LI.isCleanup(); // - The new instruction is a cleanup. SmallPtrSet<Value *, 16> AlreadyCaught; // Typeinfos known caught already. @@ -1888,8 +2207,8 @@ Instruction *InstCombiner::visitLandingPadInst(LandingPadInst &LI) { bool isLastClause = i + 1 == e; if (LI.isCatch(i)) { // A catch clause. - Value *CatchClause = LI.getClause(i); - Constant *TypeInfo = cast<Constant>(CatchClause->stripPointerCasts()); + Constant *CatchClause = LI.getClause(i); + Constant *TypeInfo = CatchClause->stripPointerCasts(); // If we already saw this clause, there is no point in having a second // copy of it. @@ -1918,7 +2237,7 @@ Instruction *InstCombiner::visitLandingPadInst(LandingPadInst &LI) { // equal (for example if one represents a C++ class, and the other some // class derived from it). assert(LI.isFilter(i) && "Unsupported landingpad clause!"); - Value *FilterClause = LI.getClause(i); + Constant *FilterClause = LI.getClause(i); ArrayType *FilterType = cast<ArrayType>(FilterClause->getType()); unsigned NumTypeInfos = FilterType->getNumElements(); @@ -1962,8 +2281,8 @@ Instruction *InstCombiner::visitLandingPadInst(LandingPadInst &LI) { // catch-alls. If so, the filter can be discarded. bool SawCatchAll = false; for (unsigned j = 0; j != NumTypeInfos; ++j) { - Value *Elt = Filter->getOperand(j); - Constant *TypeInfo = cast<Constant>(Elt->stripPointerCasts()); + Constant *Elt = Filter->getOperand(j); + Constant *TypeInfo = Elt->stripPointerCasts(); if (isCatchAll(Personality, TypeInfo)) { // This element is a catch-all. Bail out, noting this fact. SawCatchAll = true; @@ -2068,7 +2387,7 @@ Instruction *InstCombiner::visitLandingPadInst(LandingPadInst &LI) { continue; // If Filter is a subset of LFilter, i.e. every element of Filter is also // an element of LFilter, then discard LFilter. - SmallVectorImpl<Value *>::iterator J = NewClauses.begin() + j; + SmallVectorImpl<Constant *>::iterator J = NewClauses.begin() + j; // If Filter is empty then it is a subset of LFilter. if (!FElts) { // Discard LFilter. @@ -2163,7 +2482,7 @@ Instruction *InstCombiner::visitLandingPadInst(LandingPadInst &LI) { return &LI; } - return 0; + return nullptr; } @@ -2214,7 +2533,7 @@ static bool TryToSinkInstruction(Instruction *I, BasicBlock *DestBlock) { static bool AddReachableCodeToWorklist(BasicBlock *BB, SmallPtrSet<BasicBlock*, 64> &Visited, InstCombiner &IC, - const DataLayout *TD, + const DataLayout *DL, const TargetLibraryInfo *TLI) { bool MadeIRChange = false; SmallVector<BasicBlock*, 256> Worklist; @@ -2242,7 +2561,7 @@ static bool AddReachableCodeToWorklist(BasicBlock *BB, // ConstantProp instruction if trivially constant. if (!Inst->use_empty() && isa<Constant>(Inst->getOperand(0))) - if (Constant *C = ConstantFoldInstruction(Inst, TD, TLI)) { + if (Constant *C = ConstantFoldInstruction(Inst, DL, TLI)) { DEBUG(dbgs() << "IC: ConstFold to: " << *C << " from: " << *Inst << '\n'); Inst->replaceAllUsesWith(C); @@ -2251,16 +2570,16 @@ static bool AddReachableCodeToWorklist(BasicBlock *BB, continue; } - if (TD) { + if (DL) { // See if we can constant fold its operands. for (User::op_iterator i = Inst->op_begin(), e = Inst->op_end(); i != e; ++i) { ConstantExpr *CE = dyn_cast<ConstantExpr>(i); - if (CE == 0) continue; + if (CE == nullptr) continue; Constant*& FoldRes = FoldedConstants[CE]; if (!FoldRes) - FoldRes = ConstantFoldConstantExpression(CE, TD, TLI); + FoldRes = ConstantFoldConstantExpression(CE, DL, TLI); if (!FoldRes) FoldRes = CE; @@ -2327,7 +2646,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { // the reachable instructions. Ignore blocks that are not reachable. Keep // track of which blocks we visit. SmallPtrSet<BasicBlock*, 64> Visited; - MadeIRChange |= AddReachableCodeToWorklist(F.begin(), Visited, *this, TD, + MadeIRChange |= AddReachableCodeToWorklist(F.begin(), Visited, *this, DL, TLI); // Do a quick scan over the function. If we find any blocks that are @@ -2360,7 +2679,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { while (!Worklist.isEmpty()) { Instruction *I = Worklist.RemoveOne(); - if (I == 0) continue; // skip null values. + if (I == nullptr) continue; // skip null values. // Check to see if we can DCE the instruction. if (isInstructionTriviallyDead(I, TLI)) { @@ -2373,7 +2692,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { // Instruction isn't dead, see if we can constant propagate it. if (!I->use_empty() && isa<Constant>(I->getOperand(0))) - if (Constant *C = ConstantFoldInstruction(I, TD, TLI)) { + if (Constant *C = ConstantFoldInstruction(I, DL, TLI)) { DEBUG(dbgs() << "IC: ConstFold to: " << *C << " from: " << *I << '\n'); // Add operands to the worklist. @@ -2387,12 +2706,12 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { // See if we can trivially sink this instruction to a successor basic block. if (I->hasOneUse()) { BasicBlock *BB = I->getParent(); - Instruction *UserInst = cast<Instruction>(I->use_back()); + Instruction *UserInst = cast<Instruction>(*I->user_begin()); BasicBlock *UserParent; // Get the block the use occurs in. if (PHINode *PN = dyn_cast<PHINode>(UserInst)) - UserParent = PN->getIncomingBlock(I->use_begin().getUse()); + UserParent = PN->getIncomingBlock(*I->use_begin()); else UserParent = UserInst->getParent(); @@ -2408,9 +2727,18 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { // If the user is one of our immediate successors, and if that successor // only has us as a predecessors (we'd have to split the critical edge // otherwise), we can keep going. - if (UserIsSuccessor && UserParent->getSinglePredecessor()) + if (UserIsSuccessor && UserParent->getSinglePredecessor()) { // Okay, the CFG is simple enough, try to sink this instruction. - MadeIRChange |= TryToSinkInstruction(I, UserParent); + if (TryToSinkInstruction(I, UserParent)) { + MadeIRChange = true; + // We'll add uses of the sunk instruction below, but since sinking + // can expose opportunities for it's *operands* add them to the + // worklist + for (Use &U : I->operands()) + if (Instruction *OpI = dyn_cast<Instruction>(U.get())) + Worklist.Add(OpI); + } + } } } @@ -2482,23 +2810,27 @@ namespace { class InstCombinerLibCallSimplifier : public LibCallSimplifier { InstCombiner *IC; public: - InstCombinerLibCallSimplifier(const DataLayout *TD, + InstCombinerLibCallSimplifier(const DataLayout *DL, const TargetLibraryInfo *TLI, InstCombiner *IC) - : LibCallSimplifier(TD, TLI, UnsafeFPShrink) { + : LibCallSimplifier(DL, TLI, UnsafeFPShrink) { this->IC = IC; } /// replaceAllUsesWith - override so that instruction replacement /// can be defined in terms of the instruction combiner framework. - virtual void replaceAllUsesWith(Instruction *I, Value *With) const { + void replaceAllUsesWith(Instruction *I, Value *With) const override { IC->ReplaceInstUsesWith(*I, With); } }; } bool InstCombiner::runOnFunction(Function &F) { - TD = getAnalysisIfAvailable<DataLayout>(); + if (skipOptnoneFunction(F)) + return false; + + DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>(); + DL = DLP ? &DLP->getDataLayout() : nullptr; TLI = &getAnalysis<TargetLibraryInfo>(); // Minimizing size? MinimizeSize = F.getAttributes().hasAttribute(AttributeSet::FunctionIndex, @@ -2507,11 +2839,11 @@ bool InstCombiner::runOnFunction(Function &F) { /// Builder - This is an IRBuilder that automatically inserts new /// instructions into the worklist when they are created. IRBuilder<true, TargetFolder, InstCombineIRInserter> - TheBuilder(F.getContext(), TargetFolder(TD), + TheBuilder(F.getContext(), TargetFolder(DL), InstCombineIRInserter(Worklist)); Builder = &TheBuilder; - InstCombinerLibCallSimplifier TheSimplifier(TD, TLI, this); + InstCombinerLibCallSimplifier TheSimplifier(DL, TLI, this); Simplifier = &TheSimplifier; bool EverMadeChange = false; @@ -2525,7 +2857,7 @@ bool InstCombiner::runOnFunction(Function &F) { while (DoOneIteration(F, Iteration++)) EverMadeChange = true; - Builder = 0; + Builder = nullptr; return EverMadeChange; } |