diff options
Diffstat (limited to 'lib/Transforms/Utils/SimplifyCFG.cpp')
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 563 |
1 files changed, 335 insertions, 228 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index ff50b12cdb3f..24bb63bb60a5 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -11,7 +11,6 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "simplifycfg" #include "llvm/Transforms/Utils/Local.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/STLExtras.h" @@ -23,6 +22,8 @@ #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/TargetTransformInfo.h" #include "llvm/Analysis/ValueTracking.h" +#include "llvm/IR/CFG.h" +#include "llvm/IR/ConstantRange.h" #include "llvm/IR/Constants.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/DerivedTypes.h" @@ -34,14 +35,12 @@ #include "llvm/IR/MDBuilder.h" #include "llvm/IR/Metadata.h" #include "llvm/IR/Module.h" +#include "llvm/IR/NoFolder.h" #include "llvm/IR/Operator.h" +#include "llvm/IR/PatternMatch.h" #include "llvm/IR/Type.h" -#include "llvm/Support/CFG.h" #include "llvm/Support/CommandLine.h" -#include "llvm/Support/ConstantRange.h" #include "llvm/Support/Debug.h" -#include "llvm/Support/NoFolder.h" -#include "llvm/Support/PatternMatch.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include <algorithm> @@ -50,6 +49,8 @@ using namespace llvm; using namespace PatternMatch; +#define DEBUG_TYPE "simplifycfg" + static cl::opt<unsigned> PHINodeFoldingThreshold("phi-node-folding-threshold", cl::Hidden, cl::init(1), cl::desc("Control the amount of phi node folding to perform (default = 1)")); @@ -62,12 +63,13 @@ static cl::opt<bool> SinkCommon("simplifycfg-sink-common", cl::Hidden, cl::init(true), cl::desc("Sink common instructions down to the end block")); -static cl::opt<bool> -HoistCondStores("simplifycfg-hoist-cond-stores", cl::Hidden, cl::init(true), - cl::desc("Hoist conditional stores if an unconditional store preceeds")); +static cl::opt<bool> HoistCondStores( + "simplifycfg-hoist-cond-stores", cl::Hidden, cl::init(true), + cl::desc("Hoist conditional stores if an unconditional store precedes")); STATISTIC(NumBitMaps, "Number of switch instructions turned into bitmaps"); STATISTIC(NumLookupTables, "Number of switch instructions turned into lookup tables"); +STATISTIC(NumLookupTablesHoles, "Number of switch instructions turned into lookup tables (holes checked)"); STATISTIC(NumSinkCommons, "Number of common instructions sunk down to the end block"); STATISTIC(NumSpeculations, "Number of speculative executed instructions"); @@ -90,7 +92,7 @@ namespace { class SimplifyCFGOpt { const TargetTransformInfo &TTI; - const DataLayout *const TD; + const DataLayout *const DL; Value *isValueEqualityComparison(TerminatorInst *TI); BasicBlock *GetValueEqualityComparisonCases(TerminatorInst *TI, std::vector<ValueEqualityComparisonCase> &Cases); @@ -109,8 +111,8 @@ class SimplifyCFGOpt { bool SimplifyCondBranch(BranchInst *BI, IRBuilder <>&Builder); public: - SimplifyCFGOpt(const TargetTransformInfo &TTI, const DataLayout *TD) - : TTI(TTI), TD(TD) {} + SimplifyCFGOpt(const TargetTransformInfo &TTI, const DataLayout *DL) + : TTI(TTI), DL(DL) {} bool run(BasicBlock *BB); }; } @@ -199,8 +201,8 @@ static void AddPredecessorToBlock(BasicBlock *Succ, BasicBlock *NewPred, /// ComputeSpeculationCost - Compute an abstract "cost" of speculating the /// given instruction, which is assumed to be safe to speculate. 1 means /// cheap, 2 means less cheap, and UINT_MAX means prohibitively expensive. -static unsigned ComputeSpeculationCost(const User *I) { - assert(isSafeToSpeculativelyExecute(I) && +static unsigned ComputeSpeculationCost(const User *I, const DataLayout *DL) { + assert(isSafeToSpeculativelyExecute(I, DL) && "Instruction is not safe to speculatively execute!"); switch (Operator::getOpcode(I)) { default: @@ -211,6 +213,7 @@ static unsigned ComputeSpeculationCost(const User *I) { if (!cast<GEPOperator>(I)->hasAllConstantIndices()) return UINT_MAX; return 1; + case Instruction::ExtractValue: case Instruction::Load: case Instruction::Add: case Instruction::Sub: @@ -224,6 +227,9 @@ static unsigned ComputeSpeculationCost(const User *I) { case Instruction::Trunc: case Instruction::ZExt: case Instruction::SExt: + case Instruction::BitCast: + case Instruction::ExtractElement: + case Instruction::InsertElement: return 1; // These are all cheap. case Instruction::Call: @@ -251,7 +257,8 @@ static unsigned ComputeSpeculationCost(const User *I) { /// CostRemaining, false is returned and CostRemaining is undefined. static bool DominatesMergePoint(Value *V, BasicBlock *BB, SmallPtrSet<Instruction*, 4> *AggressiveInsts, - unsigned &CostRemaining) { + unsigned &CostRemaining, + const DataLayout *DL) { Instruction *I = dyn_cast<Instruction>(V); if (!I) { // Non-instructions all dominate instructions, but not all constantexprs @@ -271,12 +278,12 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB, // branch to BB, then it must be in the 'conditional' part of the "if // statement". If not, it definitely dominates the region. BranchInst *BI = dyn_cast<BranchInst>(PBB->getTerminator()); - if (BI == 0 || BI->isConditional() || BI->getSuccessor(0) != BB) + if (!BI || BI->isConditional() || BI->getSuccessor(0) != BB) return true; // If we aren't allowing aggressive promotion anymore, then don't consider // instructions in the 'if region'. - if (AggressiveInsts == 0) return false; + if (!AggressiveInsts) return false; // If we have seen this instruction before, don't count it again. if (AggressiveInsts->count(I)) return true; @@ -284,10 +291,10 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB, // Okay, it looks like the instruction IS in the "condition". Check to // see if it's a cheap instruction to unconditionally compute, and if it // only uses stuff defined outside of the condition. If so, hoist it out. - if (!isSafeToSpeculativelyExecute(I)) + if (!isSafeToSpeculativelyExecute(I, DL)) return false; - unsigned Cost = ComputeSpeculationCost(I); + unsigned Cost = ComputeSpeculationCost(I, DL); if (Cost > CostRemaining) return false; @@ -297,7 +304,7 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB, // Okay, we can only really hoist these out if their operands do // not take us over the cost threshold. for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) - if (!DominatesMergePoint(*i, BB, AggressiveInsts, CostRemaining)) + if (!DominatesMergePoint(*i, BB, AggressiveInsts, CostRemaining, DL)) return false; // Okay, it's safe to do this! Remember this instruction. AggressiveInsts->insert(I); @@ -306,15 +313,15 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB, /// GetConstantInt - Extract ConstantInt from value, looking through IntToPtr /// and PointerNullValue. Return NULL if value is not a constant int. -static ConstantInt *GetConstantInt(Value *V, const DataLayout *TD) { +static ConstantInt *GetConstantInt(Value *V, const DataLayout *DL) { // Normal constant int. ConstantInt *CI = dyn_cast<ConstantInt>(V); - if (CI || !TD || !isa<Constant>(V) || !V->getType()->isPointerTy()) + if (CI || !DL || !isa<Constant>(V) || !V->getType()->isPointerTy()) return CI; // This is some kind of pointer constant. Turn it into a pointer-sized // ConstantInt if possible. - IntegerType *PtrTy = cast<IntegerType>(TD->getIntPtrType(V->getType())); + IntegerType *PtrTy = cast<IntegerType>(DL->getIntPtrType(V->getType())); // Null pointer means 0, see SelectionDAGBuilder::getValue(const Value*). if (isa<ConstantPointerNull>(V)) @@ -331,7 +338,7 @@ static ConstantInt *GetConstantInt(Value *V, const DataLayout *TD) { return cast<ConstantInt> (ConstantExpr::getIntegerCast(CI, PtrTy, /*isSigned=*/false)); } - return 0; + return nullptr; } /// GatherConstantCompares - Given a potentially 'or'd or 'and'd together @@ -340,13 +347,13 @@ static ConstantInt *GetConstantInt(Value *V, const DataLayout *TD) { /// Values vector. static Value * GatherConstantCompares(Value *V, std::vector<ConstantInt*> &Vals, Value *&Extra, - const DataLayout *TD, bool isEQ, unsigned &UsedICmps) { + const DataLayout *DL, bool isEQ, unsigned &UsedICmps) { Instruction *I = dyn_cast<Instruction>(V); - if (I == 0) return 0; + if (!I) return nullptr; // If this is an icmp against a constant, handle this as one of the cases. if (ICmpInst *ICI = dyn_cast<ICmpInst>(I)) { - if (ConstantInt *C = GetConstantInt(I->getOperand(1), TD)) { + if (ConstantInt *C = GetConstantInt(I->getOperand(1), DL)) { Value *RHSVal; ConstantInt *RHSC; @@ -389,27 +396,27 @@ GatherConstantCompares(Value *V, std::vector<ConstantInt*> &Vals, Value *&Extra, // If there are a ton of values, we don't want to make a ginormous switch. if (Span.getSetSize().ugt(8) || Span.isEmptySet()) - return 0; + return nullptr; for (APInt Tmp = Span.getLower(); Tmp != Span.getUpper(); ++Tmp) Vals.push_back(ConstantInt::get(V->getContext(), Tmp)); UsedICmps++; return hasAdd ? RHSVal : I->getOperand(0); } - return 0; + return nullptr; } // Otherwise, we can only handle an | or &, depending on isEQ. if (I->getOpcode() != (isEQ ? Instruction::Or : Instruction::And)) - return 0; + return nullptr; unsigned NumValsBeforeLHS = Vals.size(); unsigned UsedICmpsBeforeLHS = UsedICmps; - if (Value *LHS = GatherConstantCompares(I->getOperand(0), Vals, Extra, TD, + if (Value *LHS = GatherConstantCompares(I->getOperand(0), Vals, Extra, DL, isEQ, UsedICmps)) { unsigned NumVals = Vals.size(); unsigned UsedICmpsBeforeRHS = UsedICmps; - if (Value *RHS = GatherConstantCompares(I->getOperand(1), Vals, Extra, TD, + if (Value *RHS = GatherConstantCompares(I->getOperand(1), Vals, Extra, DL, isEQ, UsedICmps)) { if (LHS == RHS) return LHS; @@ -419,33 +426,33 @@ GatherConstantCompares(Value *V, std::vector<ConstantInt*> &Vals, Value *&Extra, // The RHS of the or/and can't be folded in and we haven't used "Extra" yet, // set it and return success. - if (Extra == 0 || Extra == I->getOperand(1)) { + if (Extra == nullptr || Extra == I->getOperand(1)) { Extra = I->getOperand(1); return LHS; } Vals.resize(NumValsBeforeLHS); UsedICmps = UsedICmpsBeforeLHS; - return 0; + return nullptr; } // If the LHS can't be folded in, but Extra is available and RHS can, try to // use LHS as Extra. - if (Extra == 0 || Extra == I->getOperand(0)) { + if (Extra == nullptr || Extra == I->getOperand(0)) { Value *OldExtra = Extra; Extra = I->getOperand(0); - if (Value *RHS = GatherConstantCompares(I->getOperand(1), Vals, Extra, TD, + if (Value *RHS = GatherConstantCompares(I->getOperand(1), Vals, Extra, DL, isEQ, UsedICmps)) return RHS; assert(Vals.size() == NumValsBeforeLHS); Extra = OldExtra; } - return 0; + return nullptr; } static void EraseTerminatorInstAndDCECond(TerminatorInst *TI) { - Instruction *Cond = 0; + Instruction *Cond = nullptr; if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) { Cond = dyn_cast<Instruction>(SI->getCondition()); } else if (BranchInst *BI = dyn_cast<BranchInst>(TI)) { @@ -462,7 +469,7 @@ static void EraseTerminatorInstAndDCECond(TerminatorInst *TI) { /// isValueEqualityComparison - Return true if the specified terminator checks /// to see if a value is equal to constant integer value. Value *SimplifyCFGOpt::isValueEqualityComparison(TerminatorInst *TI) { - Value *CV = 0; + Value *CV = nullptr; if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) { // Do not permit merging of large switch instructions into their // predecessors unless there is only one predecessor. @@ -472,14 +479,14 @@ Value *SimplifyCFGOpt::isValueEqualityComparison(TerminatorInst *TI) { } else if (BranchInst *BI = dyn_cast<BranchInst>(TI)) if (BI->isConditional() && BI->getCondition()->hasOneUse()) if (ICmpInst *ICI = dyn_cast<ICmpInst>(BI->getCondition())) - if (ICI->isEquality() && GetConstantInt(ICI->getOperand(1), TD)) + if (ICI->isEquality() && GetConstantInt(ICI->getOperand(1), DL)) CV = ICI->getOperand(0); // Unwrap any lossless ptrtoint cast. - if (TD && CV) { + if (DL && CV) { if (PtrToIntInst *PTII = dyn_cast<PtrToIntInst>(CV)) { Value *Ptr = PTII->getPointerOperand(); - if (PTII->getType() == TD->getIntPtrType(Ptr->getType())) + if (PTII->getType() == DL->getIntPtrType(Ptr->getType())) CV = Ptr; } } @@ -504,7 +511,7 @@ GetValueEqualityComparisonCases(TerminatorInst *TI, ICmpInst *ICI = cast<ICmpInst>(BI->getCondition()); BasicBlock *Succ = BI->getSuccessor(ICI->getPredicate() == ICmpInst::ICMP_NE); Cases.push_back(ValueEqualityComparisonCase(GetConstantInt(ICI->getOperand(1), - TD), + DL), Succ)); return BI->getSuccessor(ICI->getPredicate() == ICmpInst::ICMP_EQ); } @@ -652,11 +659,11 @@ SimplifyEqualityComparisonWithOnlyPredecessor(TerminatorInst *TI, // Otherwise, TI's block must correspond to some matched value. Find out // which value (or set of values) this is. - ConstantInt *TIV = 0; + ConstantInt *TIV = nullptr; BasicBlock *TIBB = TI->getParent(); for (unsigned i = 0, e = PredCases.size(); i != e; ++i) if (PredCases[i].Dest == TIBB) { - if (TIV != 0) + if (TIV) return false; // Cannot handle multiple values coming to this block. TIV = PredCases[i].Value; } @@ -664,7 +671,7 @@ SimplifyEqualityComparisonWithOnlyPredecessor(TerminatorInst *TI, // Okay, we found the one constant that our value can be if we get into TI's // BB. Find out which successor will unconditionally be branched to. - BasicBlock *TheRealDest = 0; + BasicBlock *TheRealDest = nullptr; for (unsigned i = 0, e = ThisCases.size(); i != e; ++i) if (ThisCases[i].Value == TIV) { TheRealDest = ThisCases[i].Dest; @@ -672,7 +679,7 @@ SimplifyEqualityComparisonWithOnlyPredecessor(TerminatorInst *TI, } // If not handled by any explicit cases, it is handled by the default case. - if (TheRealDest == 0) TheRealDest = ThisDef; + if (!TheRealDest) TheRealDest = ThisDef; // Remove PHI node entries for dead edges. BasicBlock *CheckEdge = TheRealDest; @@ -680,7 +687,7 @@ SimplifyEqualityComparisonWithOnlyPredecessor(TerminatorInst *TI, if (*SI != CheckEdge) (*SI)->removePredecessor(TIBB); else - CheckEdge = 0; + CheckEdge = nullptr; // Insert the new branch. Instruction *NI = Builder.CreateBr(TheRealDest); @@ -732,8 +739,7 @@ static void GetBranchWeights(TerminatorInst *TI, MDNode* MD = TI->getMetadata(LLVMContext::MD_prof); assert(MD); for (unsigned i = 1, e = MD->getNumOperands(); i < e; ++i) { - ConstantInt* CI = dyn_cast<ConstantInt>(MD->getOperand(i)); - assert(CI); + ConstantInt *CI = cast<ConstantInt>(MD->getOperand(i)); Weights.push_back(CI->getValue().getZExtValue()); } @@ -748,21 +754,14 @@ static void GetBranchWeights(TerminatorInst *TI, } } -/// Sees if any of the weights are too big for a uint32_t, and halves all the -/// weights if any are. +/// Keep halving the weights until all can fit in uint32_t. static void FitWeights(MutableArrayRef<uint64_t> Weights) { - bool Halve = false; - for (unsigned i = 0; i < Weights.size(); ++i) - if (Weights[i] > UINT_MAX) { - Halve = true; - break; - } - - if (! Halve) - return; - - for (unsigned i = 0; i < Weights.size(); ++i) - Weights[i] /= 2; + uint64_t Max = *std::max_element(Weights.begin(), Weights.end()); + if (Max > UINT_MAX) { + unsigned Offset = 32 - countLeadingZeros(Max); + for (uint64_t &I : Weights) + I >>= Offset; + } } /// FoldValueComparisonIntoPredecessors - The specified terminator is a value @@ -929,8 +928,8 @@ bool SimplifyCFGOpt::FoldValueComparisonIntoPredecessors(TerminatorInst *TI, Builder.SetInsertPoint(PTI); // Convert pointer to int before we switch. if (CV->getType()->isPointerTy()) { - assert(TD && "Cannot switch on pointer without DataLayout"); - CV = Builder.CreatePtrToInt(CV, TD->getIntPtrType(CV->getType()), + assert(DL && "Cannot switch on pointer without DataLayout"); + CV = Builder.CreatePtrToInt(CV, DL->getIntPtrType(CV->getType()), "magicptr"); } @@ -957,10 +956,10 @@ bool SimplifyCFGOpt::FoldValueComparisonIntoPredecessors(TerminatorInst *TI, // Okay, last check. If BB is still a successor of PSI, then we must // have an infinite loop case. If so, add an infinitely looping block // to handle the case to preserve the behavior of the code. - BasicBlock *InfLoopBlock = 0; + BasicBlock *InfLoopBlock = nullptr; for (unsigned i = 0, e = NewSI->getNumSuccessors(); i != e; ++i) if (NewSI->getSuccessor(i) == BB) { - if (InfLoopBlock == 0) { + if (!InfLoopBlock) { // Insert it at the end of the function, because it's either code, // or it won't matter if it's hot. :) InfLoopBlock = BasicBlock::Create(BB->getContext(), @@ -999,7 +998,7 @@ static bool isSafeToHoistInvoke(BasicBlock *BB1, BasicBlock *BB2, /// HoistThenElseCodeToIf - Given a conditional branch that goes to BB1 and /// BB2, hoist any common code in the two blocks up into the branch block. The /// caller of this function guarantees that BI's block dominates BB1 and BB2. -static bool HoistThenElseCodeToIf(BranchInst *BI) { +static bool HoistThenElseCodeToIf(BranchInst *BI, const DataLayout *DL) { // This does very trivial matching, with limited scanning, to find identical // instructions in the two blocks. In particular, we don't want to get into // O(M*N) situations here where M and N are the sizes of BB1 and BB2. As @@ -1073,9 +1072,9 @@ HoistTerminator: if (BB1V == BB2V) continue; - if (isa<ConstantExpr>(BB1V) && !isSafeToSpeculativelyExecute(BB1V)) + if (isa<ConstantExpr>(BB1V) && !isSafeToSpeculativelyExecute(BB1V, DL)) return Changed; - if (isa<ConstantExpr>(BB2V) && !isSafeToSpeculativelyExecute(BB2V)) + if (isa<ConstantExpr>(BB2V) && !isSafeToSpeculativelyExecute(BB2V, DL)) return Changed; } } @@ -1106,7 +1105,7 @@ HoistTerminator: // These values do not agree. Insert a select instruction before NT // that determines the right value. SelectInst *&SI = InsertedSelects[std::make_pair(BB1V, BB2V)]; - if (SI == 0) + if (!SI) SI = cast<SelectInst> (Builder.CreateSelect(BI->getCondition(), BB1V, BB2V, BB1V->getName()+"."+BB2V->getName())); @@ -1151,7 +1150,7 @@ static bool SinkThenElseCodeToEnd(BranchInst *BI1) { // Gather the PHI nodes in BBEnd. std::map<Value*, std::pair<Value*, PHINode*> > MapValueFromBB1ToBB2; - Instruction *FirstNonPhiInBBEnd = 0; + Instruction *FirstNonPhiInBBEnd = nullptr; for (BasicBlock::iterator I = BBEnd->begin(), E = BBEnd->end(); I != E; ++I) { if (PHINode *PN = dyn_cast<PHINode>(I)) { @@ -1229,7 +1228,7 @@ static bool SinkThenElseCodeToEnd(BranchInst *BI1) { // The operands should be either the same or they need to be generated // with a PHI node after sinking. We only handle the case where there is // a single pair of different operands. - Value *DifferentOp1 = 0, *DifferentOp2 = 0; + Value *DifferentOp1 = nullptr, *DifferentOp2 = nullptr; unsigned Op1Idx = 0; for (unsigned I = 0, E = I1->getNumOperands(); I != E; ++I) { if (I1->getOperand(I) == I2->getOperand(I)) @@ -1325,11 +1324,11 @@ static Value *isSafeToSpeculateStore(Instruction *I, BasicBlock *BrBB, BasicBlock *StoreBB, BasicBlock *EndBB) { StoreInst *StoreToHoist = dyn_cast<StoreInst>(I); if (!StoreToHoist) - return 0; + return nullptr; // Volatile or atomic. if (!StoreToHoist->isSimple()) - return 0; + return nullptr; Value *StorePtr = StoreToHoist->getPointerOperand(); @@ -1341,7 +1340,7 @@ static Value *isSafeToSpeculateStore(Instruction *I, BasicBlock *BrBB, // Could be calling an instruction that effects memory like free(). if (CurI->mayHaveSideEffects() && !isa<StoreInst>(CurI)) - return 0; + return nullptr; StoreInst *SI = dyn_cast<StoreInst>(CurI); // Found the previous store make sure it stores to the same location. @@ -1349,10 +1348,10 @@ static Value *isSafeToSpeculateStore(Instruction *I, BasicBlock *BrBB, // Found the previous store, return its value operand. return SI->getValueOperand(); else if (SI) - return 0; // Unknown store. + return nullptr; // Unknown store. } - return 0; + return nullptr; } /// \brief Speculate a conditional basic block flattening the CFG. @@ -1392,7 +1391,8 @@ static Value *isSafeToSpeculateStore(Instruction *I, BasicBlock *BrBB, /// \endcode /// /// \returns true if the conditional block is removed. -static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB) { +static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB, + const DataLayout *DL) { // Be conservative for now. FP select instruction can often be expensive. Value *BrCond = BI->getCondition(); if (isa<FCmpInst>(BrCond)) @@ -1418,10 +1418,10 @@ static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB) { SmallDenseMap<Instruction *, unsigned, 4> SinkCandidateUseCounts; unsigned SpeculationCost = 0; - Value *SpeculatedStoreValue = 0; - StoreInst *SpeculatedStore = 0; + Value *SpeculatedStoreValue = nullptr; + StoreInst *SpeculatedStore = nullptr; for (BasicBlock::iterator BBI = ThenBB->begin(), - BBE = llvm::prior(ThenBB->end()); + BBE = std::prev(ThenBB->end()); BBI != BBE; ++BBI) { Instruction *I = BBI; // Skip debug info. @@ -1435,13 +1435,13 @@ static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB) { return false; // Don't hoist the instruction if it's unsafe or expensive. - if (!isSafeToSpeculativelyExecute(I) && + if (!isSafeToSpeculativelyExecute(I, DL) && !(HoistCondStores && (SpeculatedStoreValue = isSafeToSpeculateStore(I, BB, ThenBB, EndBB)))) return false; if (!SpeculatedStoreValue && - ComputeSpeculationCost(I) > PHINodeFoldingThreshold) + ComputeSpeculationCost(I, DL) > PHINodeFoldingThreshold) return false; // Store the store speculation candidate. @@ -1492,11 +1492,11 @@ static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB) { if (!OrigCE && !ThenCE) continue; // Known safe and cheap. - if ((ThenCE && !isSafeToSpeculativelyExecute(ThenCE)) || - (OrigCE && !isSafeToSpeculativelyExecute(OrigCE))) + if ((ThenCE && !isSafeToSpeculativelyExecute(ThenCE, DL)) || + (OrigCE && !isSafeToSpeculativelyExecute(OrigCE, DL))) return false; - unsigned OrigCost = OrigCE ? ComputeSpeculationCost(OrigCE) : 0; - unsigned ThenCost = ThenCE ? ComputeSpeculationCost(ThenCE) : 0; + unsigned OrigCost = OrigCE ? ComputeSpeculationCost(OrigCE, DL) : 0; + unsigned ThenCost = ThenCE ? ComputeSpeculationCost(ThenCE, DL) : 0; if (OrigCost + ThenCost > 2 * PHINodeFoldingThreshold) return false; @@ -1531,7 +1531,7 @@ static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB) { // Hoist the instructions. BB->getInstList().splice(BI, ThenBB->getInstList(), ThenBB->begin(), - llvm::prior(ThenBB->end())); + std::prev(ThenBB->end())); // Insert selects and rewrite the PHI operands. IRBuilder<true, NoFolder> Builder(BI); @@ -1589,10 +1589,9 @@ static bool BlockIsSimpleEnoughToThreadThrough(BasicBlock *BB) { // We can only support instructions that do not define values that are // live outside of the current basic block. - for (Value::use_iterator UI = BBI->use_begin(), E = BBI->use_end(); - UI != E; ++UI) { - Instruction *U = cast<Instruction>(*UI); - if (U->getParent() != BB || isa<PHINode>(U)) return false; + for (User *U : BBI->users()) { + Instruction *UI = cast<Instruction>(U); + if (UI->getParent() != BB || isa<PHINode>(UI)) return false; } // Looks ok, continue checking. @@ -1605,7 +1604,7 @@ static bool BlockIsSimpleEnoughToThreadThrough(BasicBlock *BB) { /// that is defined in the same block as the branch and if any PHI entries are /// constants, thread edges corresponding to that entry to be branches to their /// ultimate destination. -static bool FoldCondBranchOnPHI(BranchInst *BI, const DataLayout *TD) { +static bool FoldCondBranchOnPHI(BranchInst *BI, const DataLayout *DL) { BasicBlock *BB = BI->getParent(); PHINode *PN = dyn_cast<PHINode>(BI->getCondition()); // NOTE: we currently cannot transform this case if the PHI node is used @@ -1628,7 +1627,7 @@ static bool FoldCondBranchOnPHI(BranchInst *BI, const DataLayout *TD) { // constants. for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { ConstantInt *CB = dyn_cast<ConstantInt>(PN->getIncomingValue(i)); - if (CB == 0 || !CB->getType()->isIntegerTy(1)) continue; + if (!CB || !CB->getType()->isIntegerTy(1)) continue; // Okay, we now know that all edges from PredBB should be revectored to // branch to RealDest. @@ -1674,7 +1673,7 @@ static bool FoldCondBranchOnPHI(BranchInst *BI, const DataLayout *TD) { } // Check for trivial simplification. - if (Value *V = SimplifyInstruction(N, TD)) { + if (Value *V = SimplifyInstruction(N, DL)) { TranslateMap[BBI] = V; delete N; // Instruction folded away, don't need actual inst } else { @@ -1695,7 +1694,7 @@ static bool FoldCondBranchOnPHI(BranchInst *BI, const DataLayout *TD) { } // Recurse, simplifying any other constants. - return FoldCondBranchOnPHI(BI, TD) | true; + return FoldCondBranchOnPHI(BI, DL) | true; } return false; @@ -1703,7 +1702,7 @@ static bool FoldCondBranchOnPHI(BranchInst *BI, const DataLayout *TD) { /// FoldTwoEntryPHINode - Given a BB that starts with the specified two-entry /// PHI node, see if we can eliminate it. -static bool FoldTwoEntryPHINode(PHINode *PN, const DataLayout *TD) { +static bool FoldTwoEntryPHINode(PHINode *PN, const DataLayout *DL) { // Ok, this is a two entry PHI node. Check to see if this is a simple "if // statement", which has a very simple dominance structure. Basically, we // are trying to find the condition that is being branched on, which @@ -1737,23 +1736,23 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const DataLayout *TD) { for (BasicBlock::iterator II = BB->begin(); isa<PHINode>(II);) { PHINode *PN = cast<PHINode>(II++); - if (Value *V = SimplifyInstruction(PN, TD)) { + if (Value *V = SimplifyInstruction(PN, DL)) { PN->replaceAllUsesWith(V); PN->eraseFromParent(); continue; } if (!DominatesMergePoint(PN->getIncomingValue(0), BB, &AggressiveInsts, - MaxCostVal0) || + MaxCostVal0, DL) || !DominatesMergePoint(PN->getIncomingValue(1), BB, &AggressiveInsts, - MaxCostVal1)) + MaxCostVal1, DL)) return false; } // If we folded the first phi, PN dangles at this point. Refresh it. If // we ran out of PHIs then we simplified them all. PN = dyn_cast<PHINode>(BB->begin()); - if (PN == 0) return true; + if (!PN) return true; // Don't fold i1 branches on PHIs which contain binary operators. These can // often be turned into switches and other things. @@ -1767,11 +1766,11 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const DataLayout *TD) { // instructions in the predecessor blocks can be promoted as well. If // not, we won't be able to get rid of the control flow, so it's not // worth promoting to select instructions. - BasicBlock *DomBlock = 0; + BasicBlock *DomBlock = nullptr; BasicBlock *IfBlock1 = PN->getIncomingBlock(0); BasicBlock *IfBlock2 = PN->getIncomingBlock(1); if (cast<BranchInst>(IfBlock1->getTerminator())->isConditional()) { - IfBlock1 = 0; + IfBlock1 = nullptr; } else { DomBlock = *pred_begin(IfBlock1); for (BasicBlock::iterator I = IfBlock1->begin();!isa<TerminatorInst>(I);++I) @@ -1784,7 +1783,7 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const DataLayout *TD) { } if (cast<BranchInst>(IfBlock2->getTerminator())->isConditional()) { - IfBlock2 = 0; + IfBlock2 = nullptr; } else { DomBlock = *pred_begin(IfBlock2); for (BasicBlock::iterator I = IfBlock2->begin();!isa<TerminatorInst>(I);++I) @@ -1964,10 +1963,10 @@ static bool checkCSEInPredecessor(Instruction *Inst, BasicBlock *PB) { /// FoldBranchToCommonDest - If this basic block is simple enough, and if a /// predecessor branches to us and one of our successors, fold the block into /// the predecessor and use logical operations to pick the right destination. -bool llvm::FoldBranchToCommonDest(BranchInst *BI) { +bool llvm::FoldBranchToCommonDest(BranchInst *BI, const DataLayout *DL) { BasicBlock *BB = BI->getParent(); - Instruction *Cond = 0; + Instruction *Cond = nullptr; if (BI->isConditional()) Cond = dyn_cast<Instruction>(BI->getCondition()); else { @@ -1993,12 +1992,12 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { } } - if (Cond == 0) + if (!Cond) return false; } - if (Cond == 0 || (!isa<CmpInst>(Cond) && !isa<BinaryOperator>(Cond)) || - Cond->getParent() != BB || !Cond->hasOneUse()) + if (!Cond || (!isa<CmpInst>(Cond) && !isa<BinaryOperator>(Cond)) || + Cond->getParent() != BB || !Cond->hasOneUse()) return false; // Only allow this if the condition is a simple instruction that can be @@ -2013,10 +2012,10 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { // that feeds the branch. We later ensure that any values that _it_ uses // were also live in the predecessor, so that we don't unnecessarily create // register pressure or inhibit out-of-order execution. - Instruction *BonusInst = 0; + Instruction *BonusInst = nullptr; if (&*FrontIt != Cond && - FrontIt->hasOneUse() && *FrontIt->use_begin() == Cond && - isSafeToSpeculativelyExecute(FrontIt)) { + FrontIt->hasOneUse() && FrontIt->user_back() == Cond && + isSafeToSpeculativelyExecute(FrontIt, DL)) { BonusInst = &*FrontIt; ++FrontIt; @@ -2031,7 +2030,7 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { // Make sure the instruction after the condition is the cond branch. BasicBlock::iterator CondIt = Cond; ++CondIt; - // Ingore dbg intrinsics. + // Ignore dbg intrinsics. while (isa<DbgInfoIntrinsic>(CondIt)) ++CondIt; if (&*CondIt != BI) @@ -2048,7 +2047,7 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { // Finally, don't infinitely unroll conditional loops. BasicBlock *TrueDest = BI->getSuccessor(0); - BasicBlock *FalseDest = (BI->isConditional()) ? BI->getSuccessor(1) : 0; + BasicBlock *FalseDest = (BI->isConditional()) ? BI->getSuccessor(1) : nullptr; if (TrueDest == BB || FalseDest == BB) return false; @@ -2060,7 +2059,7 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { // the common successor, verify that the same value flows in from both // blocks. SmallVector<PHINode*, 4> PHIs; - if (PBI == 0 || PBI->isUnconditional() || + if (!PBI || PBI->isUnconditional() || (BI->isConditional() && !SafeToMergeTerminators(BI, PBI)) || (!BI->isConditional() && @@ -2094,7 +2093,7 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { // instructions that are used by the terminator's condition because it // exposes more merging opportunities. bool UsedByBranch = (BonusInst && BonusInst->hasOneUse() && - *BonusInst->use_begin() == Cond); + BonusInst->user_back() == Cond); if (BonusInst && !UsedByBranch) { // Collect the values used by the bonus inst @@ -2150,9 +2149,17 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { } // If we have a bonus inst, clone it into the predecessor block. - Instruction *NewBonus = 0; + Instruction *NewBonus = nullptr; if (BonusInst) { NewBonus = BonusInst->clone(); + + // If we moved a load, we cannot any longer claim any knowledge about + // its potential value. The previous information might have been valid + // only given the branch precondition. + // For an analogous reason, we must also drop all the metadata whose + // semantics we don't understand. + NewBonus->dropUnknownMetadata(LLVMContext::MD_dbg); + PredBlock->getInstList().insert(PBI, NewBonus); NewBonus->takeName(BonusInst); BonusInst->setName(BonusInst->getName()+".old"); @@ -2218,14 +2225,14 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI) { MDBuilder(BI->getContext()). createBranchWeights(MDWeights)); } else - PBI->setMetadata(LLVMContext::MD_prof, NULL); + PBI->setMetadata(LLVMContext::MD_prof, nullptr); } else { // Update PHI nodes in the common successors. for (unsigned i = 0, e = PHIs.size(); i != e; ++i) { ConstantInt *PBI_C = cast<ConstantInt>( PHIs[i]->getIncomingValueForBlock(PBI->getParent())); assert(PBI_C->getType()->isIntegerTy(1)); - Instruction *MergedCond = 0; + Instruction *MergedCond = nullptr; if (PBI->getSuccessor(0) == TrueDest) { // Create (PBI_Cond and PBI_C) or (!PBI_Cond and BI_Value) // PBI_C is true: PBI_Cond or (!PBI_Cond and BI_Value) @@ -2338,7 +2345,7 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI) { } // If this is a conditional branch in an empty block, and if any - // predecessors is a conditional branch to one of our destinations, + // predecessors are a conditional branch to one of our destinations, // fold the conditions into logical ops and one cond br. BasicBlock::iterator BBI = BB->begin(); // Ignore dbg intrinsics. @@ -2373,16 +2380,33 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI) { // Do not perform this transformation if it would require // insertion of a large number of select instructions. For targets // without predication/cmovs, this is a big pessimization. - BasicBlock *CommonDest = PBI->getSuccessor(PBIOp); + // Also do not perform this transformation if any phi node in the common + // destination block can trap when reached by BB or PBB (PR17073). In that + // case, it would be unsafe to hoist the operation into a select instruction. + + BasicBlock *CommonDest = PBI->getSuccessor(PBIOp); unsigned NumPhis = 0; for (BasicBlock::iterator II = CommonDest->begin(); - isa<PHINode>(II); ++II, ++NumPhis) + isa<PHINode>(II); ++II, ++NumPhis) { if (NumPhis > 2) // Disable this xform. return false; + PHINode *PN = cast<PHINode>(II); + Value *BIV = PN->getIncomingValueForBlock(BB); + if (ConstantExpr *CE = dyn_cast<ConstantExpr>(BIV)) + if (CE->canTrap()) + return false; + + unsigned PBBIdx = PN->getBasicBlockIndex(PBI->getParent()); + Value *PBIV = PN->getIncomingValue(PBBIdx); + if (ConstantExpr *CE = dyn_cast<ConstantExpr>(PBIV)) + if (CE->canTrap()) + return false; + } + // Finally, if everything is ok, fold the branches to logical ops. - BasicBlock *OtherDest = BI->getSuccessor(BIOp ^ 1); + BasicBlock *OtherDest = BI->getSuccessor(BIOp ^ 1); DEBUG(dbgs() << "FOLDING BRs:" << *PBI->getParent() << "AND: " << *BI->getParent()); @@ -2498,16 +2522,16 @@ static bool SimplifyTerminatorOnSelect(TerminatorInst *OldTerm, Value *Cond, // If TrueBB and FalseBB are equal, only try to preserve one copy of that // successor. BasicBlock *KeepEdge1 = TrueBB; - BasicBlock *KeepEdge2 = TrueBB != FalseBB ? FalseBB : 0; + BasicBlock *KeepEdge2 = TrueBB != FalseBB ? FalseBB : nullptr; // Then remove the rest. for (unsigned I = 0, E = OldTerm->getNumSuccessors(); I != E; ++I) { BasicBlock *Succ = OldTerm->getSuccessor(I); // Make sure only to keep exactly one copy of each edge. if (Succ == KeepEdge1) - KeepEdge1 = 0; + KeepEdge1 = nullptr; else if (Succ == KeepEdge2) - KeepEdge2 = 0; + KeepEdge2 = nullptr; else Succ->removePredecessor(OldTerm->getParent()); } @@ -2516,7 +2540,7 @@ static bool SimplifyTerminatorOnSelect(TerminatorInst *OldTerm, Value *Cond, Builder.SetCurrentDebugLocation(OldTerm->getDebugLoc()); // Insert an appropriate new terminator. - if ((KeepEdge1 == 0) && (KeepEdge2 == 0)) { + if (!KeepEdge1 && !KeepEdge2) { if (TrueBB == FalseBB) // We were only looking for one successor, and it was present. // Create an unconditional branch to it. @@ -2538,7 +2562,7 @@ static bool SimplifyTerminatorOnSelect(TerminatorInst *OldTerm, Value *Cond, // One of the selected values was a successor, but the other wasn't. // Insert an unconditional branch to the one that was found; // the edge to the one that wasn't must be unreachable. - if (KeepEdge1 == 0) + if (!KeepEdge1) // Only TrueBB was found. Builder.CreateBr(TrueBB); else @@ -2625,7 +2649,7 @@ static bool SimplifyIndirectBrOnSelect(IndirectBrInst *IBI, SelectInst *SI) { /// the PHI, merging the third icmp into the switch. static bool TryToSimplifyUncondBranchWithICmpInIt( ICmpInst *ICI, IRBuilder<> &Builder, const TargetTransformInfo &TTI, - const DataLayout *TD) { + const DataLayout *DL) { BasicBlock *BB = ICI->getParent(); // If the block has any PHIs in it or the icmp has multiple uses, it is too @@ -2639,7 +2663,7 @@ static bool TryToSimplifyUncondBranchWithICmpInIt( // 'V' and this block is the default case for the switch. In this case we can // fold the compared value into the switch to simplify things. BasicBlock *Pred = BB->getSinglePredecessor(); - if (Pred == 0 || !isa<SwitchInst>(Pred->getTerminator())) return false; + if (!Pred || !isa<SwitchInst>(Pred->getTerminator())) return false; SwitchInst *SI = cast<SwitchInst>(Pred->getTerminator()); if (SI->getCondition() != V) @@ -2653,12 +2677,12 @@ static bool TryToSimplifyUncondBranchWithICmpInIt( assert(VVal && "Should have a unique destination value"); ICI->setOperand(0, VVal); - if (Value *V = SimplifyInstruction(ICI, TD)) { + if (Value *V = SimplifyInstruction(ICI, DL)) { ICI->replaceAllUsesWith(V); ICI->eraseFromParent(); } // BB is now empty, so it is likely to simplify away. - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; } // Ok, the block is reachable from the default dest. If the constant we're @@ -2674,14 +2698,14 @@ static bool TryToSimplifyUncondBranchWithICmpInIt( ICI->replaceAllUsesWith(V); ICI->eraseFromParent(); // BB is now empty, so it is likely to simplify away. - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; } // The use of the icmp has to be in the 'end' block, by the only PHI node in // the block. BasicBlock *SuccBlock = BB->getTerminator()->getSuccessor(0); - PHINode *PHIUse = dyn_cast<PHINode>(ICI->use_back()); - if (PHIUse == 0 || PHIUse != &SuccBlock->front() || + PHINode *PHIUse = dyn_cast<PHINode>(ICI->user_back()); + if (PHIUse == nullptr || PHIUse != &SuccBlock->front() || isa<PHINode>(++BasicBlock::iterator(PHIUse))) return false; @@ -2730,32 +2754,32 @@ static bool TryToSimplifyUncondBranchWithICmpInIt( /// SimplifyBranchOnICmpChain - The specified branch is a conditional branch. /// Check to see if it is branching on an or/and chain of icmp instructions, and /// fold it into a switch instruction if so. -static bool SimplifyBranchOnICmpChain(BranchInst *BI, const DataLayout *TD, +static bool SimplifyBranchOnICmpChain(BranchInst *BI, const DataLayout *DL, IRBuilder<> &Builder) { Instruction *Cond = dyn_cast<Instruction>(BI->getCondition()); - if (Cond == 0) return false; + if (!Cond) return false; // Change br (X == 0 | X == 1), T, F into a switch instruction. // If this is a bunch of seteq's or'd together, or if it's a bunch of // 'setne's and'ed together, collect them. - Value *CompVal = 0; + Value *CompVal = nullptr; std::vector<ConstantInt*> Values; bool TrueWhenEqual = true; - Value *ExtraCase = 0; + Value *ExtraCase = nullptr; unsigned UsedICmps = 0; if (Cond->getOpcode() == Instruction::Or) { - CompVal = GatherConstantCompares(Cond, Values, ExtraCase, TD, true, + CompVal = GatherConstantCompares(Cond, Values, ExtraCase, DL, true, UsedICmps); } else if (Cond->getOpcode() == Instruction::And) { - CompVal = GatherConstantCompares(Cond, Values, ExtraCase, TD, false, + CompVal = GatherConstantCompares(Cond, Values, ExtraCase, DL, false, UsedICmps); TrueWhenEqual = false; } // If we didn't have a multiply compared value, fail. - if (CompVal == 0) return false; + if (!CompVal) return false; // Avoid turning single icmps into a switch. if (UsedICmps <= 1) @@ -2811,9 +2835,9 @@ static bool SimplifyBranchOnICmpChain(BranchInst *BI, const DataLayout *TD, Builder.SetInsertPoint(BI); // Convert pointer to int before we switch. if (CompVal->getType()->isPointerTy()) { - assert(TD && "Cannot switch on pointer without DataLayout"); + assert(DL && "Cannot switch on pointer without DataLayout"); CompVal = Builder.CreatePtrToInt(CompVal, - TD->getIntPtrType(CompVal->getType()), + DL->getIntPtrType(CompVal->getType()), "magicptr"); } @@ -3050,7 +3074,7 @@ bool SimplifyCFGOpt::SimplifyUnreachable(UnreachableInst *UI) { // Find the most popular block. unsigned MaxPop = 0; unsigned MaxIndex = 0; - BasicBlock *MaxBlock = 0; + BasicBlock *MaxBlock = nullptr; for (std::map<BasicBlock*, std::pair<unsigned, unsigned> >::iterator I = Popularity.begin(), E = Popularity.end(); I != E; ++I) { if (I->second.first > MaxPop || @@ -3188,7 +3212,7 @@ static bool EliminateDeadSwitchCases(SwitchInst *SI) { Value *Cond = SI->getCondition(); unsigned Bits = Cond->getType()->getIntegerBitWidth(); APInt KnownZero(Bits, 0), KnownOne(Bits, 0); - ComputeMaskedBits(Cond, KnownZero, KnownOne); + computeKnownBits(Cond, KnownZero, KnownOne); // Gather dead cases. SmallVector<ConstantInt*, 8> DeadCases; @@ -3222,7 +3246,7 @@ static bool EliminateDeadSwitchCases(SwitchInst *SI) { Case.getCaseSuccessor()->removePredecessor(SI->getParent()); SI->removeCase(Case); } - if (HasWeight) { + if (HasWeight && Weights.size() >= 2) { SmallVector<uint32_t, 8> MDWeights(Weights.begin(), Weights.end()); SI->setMetadata(LLVMContext::MD_prof, MDBuilder(SI->getParent()->getContext()). @@ -3241,13 +3265,13 @@ static PHINode *FindPHIForConditionForwarding(ConstantInt *CaseValue, BasicBlock *BB, int *PhiIndex) { if (BB->getFirstNonPHIOrDbg() != BB->getTerminator()) - return NULL; // BB must be empty to be a candidate for simplification. + return nullptr; // BB must be empty to be a candidate for simplification. if (!BB->getSinglePredecessor()) - return NULL; // BB must be dominated by the switch. + return nullptr; // BB must be dominated by the switch. BranchInst *Branch = dyn_cast<BranchInst>(BB->getTerminator()); if (!Branch || !Branch->isUnconditional()) - return NULL; // Terminator must be unconditional branch. + return nullptr; // Terminator must be unconditional branch. BasicBlock *Succ = Branch->getSuccessor(0); @@ -3263,7 +3287,7 @@ static PHINode *FindPHIForConditionForwarding(ConstantInt *CaseValue, return PHI; } - return NULL; + return nullptr; } /// ForwardSwitchConditionToPHI - Try to forward the condition of a switch @@ -3306,6 +3330,11 @@ static bool ForwardSwitchConditionToPHI(SwitchInst *SI) { /// ValidLookupTableConstant - Return true if the backend will be able to handle /// initializing an array of constants like C. static bool ValidLookupTableConstant(Constant *C) { + if (C->isThreadDependent()) + return false; + if (C->isDLLImportDependent()) + return false; + if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) return CE->isGEPWithNoNotionalOverIndexing(); @@ -3336,12 +3365,12 @@ ConstantFold(Instruction *I, if (SelectInst *Select = dyn_cast<SelectInst>(I)) { Constant *A = LookupConstant(Select->getCondition(), ConstantPool); if (!A) - return 0; + return nullptr; if (A->isAllOnesValue()) return LookupConstant(Select->getTrueValue(), ConstantPool); if (A->isNullValue()) return LookupConstant(Select->getFalseValue(), ConstantPool); - return 0; + return nullptr; } SmallVector<Constant *, 4> COps; @@ -3349,7 +3378,7 @@ ConstantFold(Instruction *I, if (Constant *A = LookupConstant(I->getOperand(N), ConstantPool)) COps.push_back(A); else - return 0; + return nullptr; } if (CmpInst *Cmp = dyn_cast<CmpInst>(I)) @@ -3428,7 +3457,7 @@ GetCaseResults(SwitchInst *SI, Res.push_back(std::make_pair(PHI, ConstVal)); } - return true; + return Res.size() > 0; } namespace { @@ -3444,7 +3473,7 @@ namespace { ConstantInt *Offset, const SmallVectorImpl<std::pair<ConstantInt*, Constant*> >& Values, Constant *DefaultValue, - const DataLayout *TD); + const DataLayout *DL); /// BuildLookup - Build instructions with Builder to retrieve the value at /// the position given by Index in the lookup table. @@ -3452,7 +3481,7 @@ namespace { /// WouldFitInRegister - Return true if a table with TableSize elements of /// type ElementType would fit in a target-legal register. - static bool WouldFitInRegister(const DataLayout *TD, + static bool WouldFitInRegister(const DataLayout *DL, uint64_t TableSize, const Type *ElementType); @@ -3491,38 +3520,44 @@ SwitchLookupTable::SwitchLookupTable(Module &M, ConstantInt *Offset, const SmallVectorImpl<std::pair<ConstantInt*, Constant*> >& Values, Constant *DefaultValue, - const DataLayout *TD) - : SingleValue(0), BitMap(0), BitMapElementTy(0), Array(0) { + const DataLayout *DL) + : SingleValue(nullptr), BitMap(nullptr), BitMapElementTy(nullptr), + Array(nullptr) { assert(Values.size() && "Can't build lookup table without values!"); assert(TableSize >= Values.size() && "Can't fit values in table!"); // If all values in the table are equal, this is that value. SingleValue = Values.begin()->second; + Type *ValueType = Values.begin()->second->getType(); + // Build up the table contents. SmallVector<Constant*, 64> TableContents(TableSize); for (size_t I = 0, E = Values.size(); I != E; ++I) { ConstantInt *CaseVal = Values[I].first; Constant *CaseRes = Values[I].second; - assert(CaseRes->getType() == DefaultValue->getType()); + assert(CaseRes->getType() == ValueType); uint64_t Idx = (CaseVal->getValue() - Offset->getValue()) .getLimitedValue(); TableContents[Idx] = CaseRes; if (CaseRes != SingleValue) - SingleValue = 0; + SingleValue = nullptr; } // Fill in any holes in the table with the default result. if (Values.size() < TableSize) { + assert(DefaultValue && + "Need a default value to fill the lookup table holes."); + assert(DefaultValue->getType() == ValueType); for (uint64_t I = 0; I < TableSize; ++I) { if (!TableContents[I]) TableContents[I] = DefaultValue; } if (DefaultValue != SingleValue) - SingleValue = 0; + SingleValue = nullptr; } // If each element in the table contains the same value, we only need to store @@ -3533,8 +3568,8 @@ SwitchLookupTable::SwitchLookupTable(Module &M, } // If the type is integer and the table fits in a register, build a bitmap. - if (WouldFitInRegister(TD, TableSize, DefaultValue->getType())) { - IntegerType *IT = cast<IntegerType>(DefaultValue->getType()); + if (WouldFitInRegister(DL, TableSize, ValueType)) { + IntegerType *IT = cast<IntegerType>(ValueType); APInt TableInt(TableSize * IT->getBitWidth(), 0); for (uint64_t I = TableSize; I > 0; --I) { TableInt <<= IT->getBitWidth(); @@ -3552,7 +3587,7 @@ SwitchLookupTable::SwitchLookupTable(Module &M, } // Store the table in an array. - ArrayType *ArrayTy = ArrayType::get(DefaultValue->getType(), TableSize); + ArrayType *ArrayTy = ArrayType::get(ValueType, TableSize); Constant *Initializer = ConstantArray::get(ArrayTy, TableContents); Array = new GlobalVariable(M, ArrayTy, /*constant=*/ true, @@ -3589,6 +3624,16 @@ Value *SwitchLookupTable::BuildLookup(Value *Index, IRBuilder<> &Builder) { "switch.masked"); } case ArrayKind: { + // Make sure the table index will not overflow when treated as signed. + IntegerType *IT = cast<IntegerType>(Index->getType()); + uint64_t TableSize = Array->getInitializer()->getType() + ->getArrayNumElements(); + if (TableSize > (1ULL << (IT->getBitWidth() - 1))) + Index = Builder.CreateZExt(Index, + IntegerType::get(IT->getContext(), + IT->getBitWidth() + 1), + "switch.tableidx.zext"); + Value *GEPIndices[] = { Builder.getInt32(0), Index }; Value *GEP = Builder.CreateInBoundsGEP(Array, GEPIndices, "switch.gep"); @@ -3598,10 +3643,10 @@ Value *SwitchLookupTable::BuildLookup(Value *Index, IRBuilder<> &Builder) { llvm_unreachable("Unknown lookup table kind!"); } -bool SwitchLookupTable::WouldFitInRegister(const DataLayout *TD, +bool SwitchLookupTable::WouldFitInRegister(const DataLayout *DL, uint64_t TableSize, const Type *ElementType) { - if (!TD) + if (!DL) return false; const IntegerType *IT = dyn_cast<IntegerType>(ElementType); if (!IT) @@ -3612,7 +3657,7 @@ bool SwitchLookupTable::WouldFitInRegister(const DataLayout *TD, // Avoid overflow, fitsInLegalInteger uses unsigned int for the width. if (TableSize >= UINT_MAX/IT->getBitWidth()) return false; - return TD->fitsInLegalInteger(TableSize * IT->getBitWidth()); + return DL->fitsInLegalInteger(TableSize * IT->getBitWidth()); } /// ShouldBuildLookupTable - Determine whether a lookup table should be built @@ -3621,7 +3666,7 @@ bool SwitchLookupTable::WouldFitInRegister(const DataLayout *TD, static bool ShouldBuildLookupTable(SwitchInst *SI, uint64_t TableSize, const TargetTransformInfo &TTI, - const DataLayout *TD, + const DataLayout *DL, const SmallDenseMap<PHINode*, Type*>& ResultTypes) { if (SI->getNumCases() > TableSize || TableSize >= UINT64_MAX / 10) return false; // TableSize overflowed, or mul below might overflow. @@ -3637,7 +3682,7 @@ static bool ShouldBuildLookupTable(SwitchInst *SI, // Saturate this flag to false. AllTablesFitInRegister = AllTablesFitInRegister && - SwitchLookupTable::WouldFitInRegister(TD, TableSize, Ty); + SwitchLookupTable::WouldFitInRegister(DL, TableSize, Ty); // If both flags saturate, we're done. NOTE: This *only* works with // saturating flags, and all flags have to saturate first due to the @@ -3666,7 +3711,7 @@ static bool ShouldBuildLookupTable(SwitchInst *SI, static bool SwitchToLookupTable(SwitchInst *SI, IRBuilder<> &Builder, const TargetTransformInfo &TTI, - const DataLayout* TD) { + const DataLayout* DL) { assert(SI->getNumCases() > 1 && "Degenerate switch?"); // Only build lookup table when we have a target that supports it. @@ -3680,11 +3725,9 @@ static bool SwitchToLookupTable(SwitchInst *SI, // GEP needs a runtime relocation in PIC code. We should just build one big // string and lookup indices into that. - // Ignore the switch if the number of cases is too small. - // This is similar to the check when building jump tables in - // SelectionDAGBuilder::handleJTSwitchCase. - // FIXME: Determine the best cut-off. - if (SI->getNumCases() < 4) + // Ignore switches with less than three cases. Lookup tables will not make them + // faster, so we don't analyze them. + if (SI->getNumCases() < 3) return false; // Figure out the corresponding result for each case value and phi node in the @@ -3694,7 +3737,7 @@ static bool SwitchToLookupTable(SwitchInst *SI, ConstantInt *MinCaseVal = CI.getCaseValue(); ConstantInt *MaxCaseVal = CI.getCaseValue(); - BasicBlock *CommonDest = 0; + BasicBlock *CommonDest = nullptr; typedef SmallVector<std::pair<ConstantInt*, Constant*>, 4> ResultListTy; SmallDenseMap<PHINode*, ResultListTy> ResultLists; SmallDenseMap<PHINode*, Constant*> DefaultResults; @@ -3712,7 +3755,7 @@ static bool SwitchToLookupTable(SwitchInst *SI, typedef SmallVector<std::pair<PHINode*, Constant*>, 4> ResultsTy; ResultsTy Results; if (!GetCaseResults(SI, CaseVal, CI.getCaseSuccessor(), &CommonDest, - Results, TD)) + Results, DL)) return false; // Append the result from this case to the list for each phi. @@ -3723,21 +3766,41 @@ static bool SwitchToLookupTable(SwitchInst *SI, } } - // Get the resulting values for the default case. + // Keep track of the result types. + for (size_t I = 0, E = PHIs.size(); I != E; ++I) { + PHINode *PHI = PHIs[I]; + ResultTypes[PHI] = ResultLists[PHI][0].second->getType(); + } + + uint64_t NumResults = ResultLists[PHIs[0]].size(); + APInt RangeSpread = MaxCaseVal->getValue() - MinCaseVal->getValue(); + uint64_t TableSize = RangeSpread.getLimitedValue() + 1; + bool TableHasHoles = (NumResults < TableSize); + + // If the table has holes, we need a constant result for the default case + // or a bitmask that fits in a register. SmallVector<std::pair<PHINode*, Constant*>, 4> DefaultResultsList; - if (!GetCaseResults(SI, 0, SI->getDefaultDest(), &CommonDest, - DefaultResultsList, TD)) - return false; + bool HasDefaultResults = false; + if (TableHasHoles) { + HasDefaultResults = GetCaseResults(SI, nullptr, SI->getDefaultDest(), + &CommonDest, DefaultResultsList, DL); + } + bool NeedMask = (TableHasHoles && !HasDefaultResults); + if (NeedMask) { + // As an extra penalty for the validity test we require more cases. + if (SI->getNumCases() < 4) // FIXME: Find best threshold value (benchmark). + return false; + if (!(DL && DL->fitsInLegalInteger(TableSize))) + return false; + } + for (size_t I = 0, E = DefaultResultsList.size(); I != E; ++I) { PHINode *PHI = DefaultResultsList[I].first; Constant *Result = DefaultResultsList[I].second; DefaultResults[PHI] = Result; - ResultTypes[PHI] = Result->getType(); } - APInt RangeSpread = MaxCaseVal->getValue() - MinCaseVal->getValue(); - uint64_t TableSize = RangeSpread.getLimitedValue() + 1; - if (!ShouldBuildLookupTable(SI, TableSize, TTI, TD, ResultTypes)) + if (!ShouldBuildLookupTable(SI, TableSize, TTI, DL, ResultTypes)) return false; // Create the BB that does the lookups. @@ -3755,7 +3818,7 @@ static bool SwitchToLookupTable(SwitchInst *SI, // Compute the maximum table size representable by the integer type we are // switching upon. unsigned CaseSize = MinCaseVal->getType()->getPrimitiveSizeInBits(); - uint64_t MaxTableSize = CaseSize > 63? UINT64_MAX : 1ULL << CaseSize; + uint64_t MaxTableSize = CaseSize > 63 ? UINT64_MAX : 1ULL << CaseSize; assert(MaxTableSize >= TableSize && "It is impossible for a switch to have more entries than the max " "representable value of its input integer type's size."); @@ -3770,25 +3833,67 @@ static bool SwitchToLookupTable(SwitchInst *SI, SI->getDefaultDest()->removePredecessor(SI->getParent()); } else { Value *Cmp = Builder.CreateICmpULT(TableIndex, ConstantInt::get( - MinCaseVal->getType(), TableSize)); + MinCaseVal->getType(), TableSize)); Builder.CreateCondBr(Cmp, LookupBB, SI->getDefaultDest()); } // Populate the BB that does the lookups. Builder.SetInsertPoint(LookupBB); + + if (NeedMask) { + // Before doing the lookup we do the hole check. + // The LookupBB is therefore re-purposed to do the hole check + // and we create a new LookupBB. + BasicBlock *MaskBB = LookupBB; + MaskBB->setName("switch.hole_check"); + LookupBB = BasicBlock::Create(Mod.getContext(), + "switch.lookup", + CommonDest->getParent(), + CommonDest); + + // Build bitmask; fill in a 1 bit for every case. + APInt MaskInt(TableSize, 0); + APInt One(TableSize, 1); + const ResultListTy &ResultList = ResultLists[PHIs[0]]; + for (size_t I = 0, E = ResultList.size(); I != E; ++I) { + uint64_t Idx = (ResultList[I].first->getValue() - + MinCaseVal->getValue()).getLimitedValue(); + MaskInt |= One << Idx; + } + ConstantInt *TableMask = ConstantInt::get(Mod.getContext(), MaskInt); + + // Get the TableIndex'th bit of the bitmask. + // If this bit is 0 (meaning hole) jump to the default destination, + // else continue with table lookup. + IntegerType *MapTy = TableMask->getType(); + Value *MaskIndex = Builder.CreateZExtOrTrunc(TableIndex, MapTy, + "switch.maskindex"); + Value *Shifted = Builder.CreateLShr(TableMask, MaskIndex, + "switch.shifted"); + Value *LoBit = Builder.CreateTrunc(Shifted, + Type::getInt1Ty(Mod.getContext()), + "switch.lobit"); + Builder.CreateCondBr(LoBit, LookupBB, SI->getDefaultDest()); + + Builder.SetInsertPoint(LookupBB); + AddPredecessorToBlock(SI->getDefaultDest(), MaskBB, SI->getParent()); + } + bool ReturnedEarly = false; for (size_t I = 0, E = PHIs.size(); I != E; ++I) { PHINode *PHI = PHIs[I]; + // If using a bitmask, use any value to fill the lookup table holes. + Constant *DV = NeedMask ? ResultLists[PHI][0].second : DefaultResults[PHI]; SwitchLookupTable Table(Mod, TableSize, MinCaseVal, ResultLists[PHI], - DefaultResults[PHI], TD); + DV, DL); Value *Result = Table.BuildLookup(TableIndex, Builder); // If the result is used to return immediately from the function, we want to // do that right here. - if (PHI->hasOneUse() && isa<ReturnInst>(*PHI->use_begin()) && - *PHI->use_begin() == CommonDest->getFirstNonPHIOrDbg()) { + if (PHI->hasOneUse() && isa<ReturnInst>(*PHI->user_begin()) && + PHI->user_back() == CommonDest->getFirstNonPHIOrDbg()) { Builder.CreateRet(Result); ReturnedEarly = true; break; @@ -3811,6 +3916,8 @@ static bool SwitchToLookupTable(SwitchInst *SI, SI->eraseFromParent(); ++NumLookupTables; + if (NeedMask) + ++NumLookupTablesHoles; return true; } @@ -3822,12 +3929,12 @@ bool SimplifyCFGOpt::SimplifySwitch(SwitchInst *SI, IRBuilder<> &Builder) { // see if that predecessor totally determines the outcome of this switch. if (BasicBlock *OnlyPred = BB->getSinglePredecessor()) if (SimplifyEqualityComparisonWithOnlyPredecessor(SI, OnlyPred, Builder)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; Value *Cond = SI->getCondition(); if (SelectInst *Select = dyn_cast<SelectInst>(Cond)) if (SimplifySwitchOnSelect(SI, Select)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; // If the block only contains the switch, see if we can fold the block // away into any preds. @@ -3837,22 +3944,22 @@ bool SimplifyCFGOpt::SimplifySwitch(SwitchInst *SI, IRBuilder<> &Builder) { ++BBI; if (SI == &*BBI) if (FoldValueComparisonIntoPredecessors(SI, Builder)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; } // Try to transform the switch into an icmp and a branch. if (TurnSwitchRangeIntoICmp(SI, Builder)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; // Remove unreachable cases. if (EliminateDeadSwitchCases(SI)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; if (ForwardSwitchConditionToPHI(SI)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; - if (SwitchToLookupTable(SI, Builder, TTI, TD)) - return SimplifyCFG(BB, TTI, TD) | true; + if (SwitchToLookupTable(SI, Builder, TTI, DL)) + return SimplifyCFG(BB, TTI, DL) | true; return false; } @@ -3889,7 +3996,7 @@ bool SimplifyCFGOpt::SimplifyIndirectBr(IndirectBrInst *IBI) { if (SelectInst *SI = dyn_cast<SelectInst>(IBI->getAddress())) { if (SimplifyIndirectBrOnSelect(IBI, SI)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; } return Changed; } @@ -3913,7 +4020,7 @@ bool SimplifyCFGOpt::SimplifyUncondBranch(BranchInst *BI, IRBuilder<> &Builder){ for (++I; isa<DbgInfoIntrinsic>(I); ++I) ; if (I->isTerminator() && - TryToSimplifyUncondBranchWithICmpInIt(ICI, Builder, TTI, TD)) + TryToSimplifyUncondBranchWithICmpInIt(ICI, Builder, TTI, DL)) return true; } @@ -3921,8 +4028,8 @@ bool SimplifyCFGOpt::SimplifyUncondBranch(BranchInst *BI, IRBuilder<> &Builder){ // branches to us and our successor, fold the comparison into the // predecessor and use logical operations to update the incoming value // for PHI nodes in common successor. - if (FoldBranchToCommonDest(BI)) - return SimplifyCFG(BB, TTI, TD) | true; + if (FoldBranchToCommonDest(BI, DL)) + return SimplifyCFG(BB, TTI, DL) | true; return false; } @@ -3937,7 +4044,7 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { // switch. if (BasicBlock *OnlyPred = BB->getSinglePredecessor()) if (SimplifyEqualityComparisonWithOnlyPredecessor(BI, OnlyPred, Builder)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; // This block must be empty, except for the setcond inst, if it exists. // Ignore dbg intrinsics. @@ -3947,67 +4054,67 @@ bool SimplifyCFGOpt::SimplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) { ++I; if (&*I == BI) { if (FoldValueComparisonIntoPredecessors(BI, Builder)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; } else if (&*I == cast<Instruction>(BI->getCondition())){ ++I; // Ignore dbg intrinsics. while (isa<DbgInfoIntrinsic>(I)) ++I; if (&*I == BI && FoldValueComparisonIntoPredecessors(BI, Builder)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; } } // Try to turn "br (X == 0 | X == 1), T, F" into a switch instruction. - if (SimplifyBranchOnICmpChain(BI, TD, Builder)) + if (SimplifyBranchOnICmpChain(BI, DL, Builder)) return true; // If this basic block is ONLY a compare and a branch, and if a predecessor // branches to us and one of our successors, fold the comparison into the // predecessor and use logical operations to pick the right destination. - if (FoldBranchToCommonDest(BI)) - return SimplifyCFG(BB, TTI, TD) | true; + if (FoldBranchToCommonDest(BI, DL)) + return SimplifyCFG(BB, TTI, DL) | true; // We have a conditional branch to two blocks that are only reachable // from BI. We know that the condbr dominates the two blocks, so see if // there is any identical code in the "then" and "else" blocks. If so, we // can hoist it up to the branching block. - if (BI->getSuccessor(0)->getSinglePredecessor() != 0) { - if (BI->getSuccessor(1)->getSinglePredecessor() != 0) { - if (HoistThenElseCodeToIf(BI)) - return SimplifyCFG(BB, TTI, TD) | true; + if (BI->getSuccessor(0)->getSinglePredecessor()) { + if (BI->getSuccessor(1)->getSinglePredecessor()) { + if (HoistThenElseCodeToIf(BI, DL)) + return SimplifyCFG(BB, TTI, DL) | true; } else { // If Successor #1 has multiple preds, we may be able to conditionally - // execute Successor #0 if it branches to successor #1. + // execute Successor #0 if it branches to Successor #1. TerminatorInst *Succ0TI = BI->getSuccessor(0)->getTerminator(); if (Succ0TI->getNumSuccessors() == 1 && Succ0TI->getSuccessor(0) == BI->getSuccessor(1)) - if (SpeculativelyExecuteBB(BI, BI->getSuccessor(0))) - return SimplifyCFG(BB, TTI, TD) | true; + if (SpeculativelyExecuteBB(BI, BI->getSuccessor(0), DL)) + return SimplifyCFG(BB, TTI, DL) | true; } - } else if (BI->getSuccessor(1)->getSinglePredecessor() != 0) { + } else if (BI->getSuccessor(1)->getSinglePredecessor()) { // If Successor #0 has multiple preds, we may be able to conditionally - // execute Successor #1 if it branches to successor #0. + // execute Successor #1 if it branches to Successor #0. TerminatorInst *Succ1TI = BI->getSuccessor(1)->getTerminator(); if (Succ1TI->getNumSuccessors() == 1 && Succ1TI->getSuccessor(0) == BI->getSuccessor(0)) - if (SpeculativelyExecuteBB(BI, BI->getSuccessor(1))) - return SimplifyCFG(BB, TTI, TD) | true; + if (SpeculativelyExecuteBB(BI, BI->getSuccessor(1), DL)) + return SimplifyCFG(BB, TTI, DL) | true; } // If this is a branch on a phi node in the current block, thread control // through this block if any PHI node entries are constants. if (PHINode *PN = dyn_cast<PHINode>(BI->getCondition())) if (PN->getParent() == BI->getParent()) - if (FoldCondBranchOnPHI(BI, TD)) - return SimplifyCFG(BB, TTI, TD) | true; + if (FoldCondBranchOnPHI(BI, DL)) + return SimplifyCFG(BB, TTI, DL) | true; // Scan predecessor blocks for conditional branches. for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) if (BranchInst *PBI = dyn_cast<BranchInst>((*PI)->getTerminator())) if (PBI != BI && PBI->isConditional()) if (SimplifyCondBranchToCondBranch(PBI, BI)) - return SimplifyCFG(BB, TTI, TD) | true; + return SimplifyCFG(BB, TTI, DL) | true; return false; } @@ -4023,7 +4130,7 @@ static bool passingValueIsAlwaysUndefined(Value *V, Instruction *I) { if (C->isNullValue()) { // Only look at the first use, avoid hurting compile time with long uselists - User *Use = *I->use_begin(); + User *Use = *I->user_begin(); // Now make sure that there are no instructions in between that can alter // control flow (eg. calls) @@ -4119,7 +4226,7 @@ bool SimplifyCFGOpt::run(BasicBlock *BB) { // eliminate it, do so now. if (PHINode *PN = dyn_cast<PHINode>(BB->begin())) if (PN->getNumIncomingValues() == 2) - Changed |= FoldTwoEntryPHINode(PN, TD); + Changed |= FoldTwoEntryPHINode(PN, DL); Builder.SetInsertPoint(BB->getTerminator()); if (BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator())) { @@ -4151,6 +4258,6 @@ bool SimplifyCFGOpt::run(BasicBlock *BB) { /// of the CFG. It returns true if a modification was made. /// bool llvm::SimplifyCFG(BasicBlock *BB, const TargetTransformInfo &TTI, - const DataLayout *TD) { - return SimplifyCFGOpt(TTI, TD).run(BB); + const DataLayout *DL) { + return SimplifyCFGOpt(TTI, DL).run(BB); } |