| //===- BBVectorize.cpp - A Basic-Block Vectorizer -------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements a basic-block vectorization pass. The algorithm was |
| // inspired by that used by the Vienna MAP Vectorizor by Franchetti and Kral, |
| // et al. It works by looking for chains of pairable operations and then |
| // pairing them. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define BBV_NAME "bb-vectorize" |
| #define DEBUG_TYPE BBV_NAME |
| #include "llvm/Transforms/Vectorize.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/DenseSet.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/ADT/SmallSet.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/Analysis/AliasAnalysis.h" |
| #include "llvm/Analysis/AliasSetTracker.h" |
| #include "llvm/Analysis/Dominators.h" |
| #include "llvm/Analysis/ScalarEvolution.h" |
| #include "llvm/Analysis/ScalarEvolutionExpressions.h" |
| #include "llvm/Analysis/TargetTransformInfo.h" |
| #include "llvm/Analysis/ValueTracking.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/DerivedTypes.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/Instructions.h" |
| #include "llvm/IR/IntrinsicInst.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/IR/LLVMContext.h" |
| #include "llvm/IR/Metadata.h" |
| #include "llvm/IR/Type.h" |
| #include "llvm/Pass.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Debug.h" |
| #include "llvm/Support/ValueHandle.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Transforms/Utils/Local.h" |
| #include <algorithm> |
| using namespace llvm; |
| |
| static cl::opt<bool> |
| IgnoreTargetInfo("bb-vectorize-ignore-target-info", cl::init(false), |
| cl::Hidden, cl::desc("Ignore target information")); |
| |
| static cl::opt<unsigned> |
| ReqChainDepth("bb-vectorize-req-chain-depth", cl::init(6), cl::Hidden, |
| cl::desc("The required chain depth for vectorization")); |
| |
| static cl::opt<bool> |
| UseChainDepthWithTI("bb-vectorize-use-chain-depth", cl::init(false), |
| cl::Hidden, cl::desc("Use the chain depth requirement with" |
| " target information")); |
| |
| static cl::opt<unsigned> |
| SearchLimit("bb-vectorize-search-limit", cl::init(400), cl::Hidden, |
| cl::desc("The maximum search distance for instruction pairs")); |
| |
| static cl::opt<bool> |
| SplatBreaksChain("bb-vectorize-splat-breaks-chain", cl::init(false), cl::Hidden, |
| cl::desc("Replicating one element to a pair breaks the chain")); |
| |
| static cl::opt<unsigned> |
| VectorBits("bb-vectorize-vector-bits", cl::init(128), cl::Hidden, |
| cl::desc("The size of the native vector registers")); |
| |
| static cl::opt<unsigned> |
| MaxIter("bb-vectorize-max-iter", cl::init(0), cl::Hidden, |
| cl::desc("The maximum number of pairing iterations")); |
| |
| static cl::opt<bool> |
| Pow2LenOnly("bb-vectorize-pow2-len-only", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to form non-2^n-length vectors")); |
| |
| static cl::opt<unsigned> |
| MaxInsts("bb-vectorize-max-instr-per-group", cl::init(500), cl::Hidden, |
| cl::desc("The maximum number of pairable instructions per group")); |
| |
| static cl::opt<unsigned> |
| MaxPairs("bb-vectorize-max-pairs-per-group", cl::init(3000), cl::Hidden, |
| cl::desc("The maximum number of candidate instruction pairs per group")); |
| |
| static cl::opt<unsigned> |
| MaxCandPairsForCycleCheck("bb-vectorize-max-cycle-check-pairs", cl::init(200), |
| cl::Hidden, cl::desc("The maximum number of candidate pairs with which to use" |
| " a full cycle check")); |
| |
| static cl::opt<bool> |
| NoBools("bb-vectorize-no-bools", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize boolean (i1) values")); |
| |
| static cl::opt<bool> |
| NoInts("bb-vectorize-no-ints", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize integer values")); |
| |
| static cl::opt<bool> |
| NoFloats("bb-vectorize-no-floats", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize floating-point values")); |
| |
| // FIXME: This should default to false once pointer vector support works. |
| static cl::opt<bool> |
| NoPointers("bb-vectorize-no-pointers", cl::init(/*false*/ true), cl::Hidden, |
| cl::desc("Don't try to vectorize pointer values")); |
| |
| static cl::opt<bool> |
| NoCasts("bb-vectorize-no-casts", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize casting (conversion) operations")); |
| |
| static cl::opt<bool> |
| NoMath("bb-vectorize-no-math", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize floating-point math intrinsics")); |
| |
| static cl::opt<bool> |
| NoFMA("bb-vectorize-no-fma", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize the fused-multiply-add intrinsic")); |
| |
| static cl::opt<bool> |
| NoSelect("bb-vectorize-no-select", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize select instructions")); |
| |
| static cl::opt<bool> |
| NoCmp("bb-vectorize-no-cmp", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize comparison instructions")); |
| |
| static cl::opt<bool> |
| NoGEP("bb-vectorize-no-gep", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize getelementptr instructions")); |
| |
| static cl::opt<bool> |
| NoMemOps("bb-vectorize-no-mem-ops", cl::init(false), cl::Hidden, |
| cl::desc("Don't try to vectorize loads and stores")); |
| |
| static cl::opt<bool> |
| AlignedOnly("bb-vectorize-aligned-only", cl::init(false), cl::Hidden, |
| cl::desc("Only generate aligned loads and stores")); |
| |
| static cl::opt<bool> |
| NoMemOpBoost("bb-vectorize-no-mem-op-boost", |
| cl::init(false), cl::Hidden, |
| cl::desc("Don't boost the chain-depth contribution of loads and stores")); |
| |
| static cl::opt<bool> |
| FastDep("bb-vectorize-fast-dep", cl::init(false), cl::Hidden, |
| cl::desc("Use a fast instruction dependency analysis")); |
| |
| #ifndef NDEBUG |
| static cl::opt<bool> |
| DebugInstructionExamination("bb-vectorize-debug-instruction-examination", |
| cl::init(false), cl::Hidden, |
| cl::desc("When debugging is enabled, output information on the" |
| " instruction-examination process")); |
| static cl::opt<bool> |
| DebugCandidateSelection("bb-vectorize-debug-candidate-selection", |
| cl::init(false), cl::Hidden, |
| cl::desc("When debugging is enabled, output information on the" |
| " candidate-selection process")); |
| static cl::opt<bool> |
| DebugPairSelection("bb-vectorize-debug-pair-selection", |
| cl::init(false), cl::Hidden, |
| cl::desc("When debugging is enabled, output information on the" |
| " pair-selection process")); |
| static cl::opt<bool> |
| DebugCycleCheck("bb-vectorize-debug-cycle-check", |
| cl::init(false), cl::Hidden, |
| cl::desc("When debugging is enabled, output information on the" |
| " cycle-checking process")); |
| |
| static cl::opt<bool> |
| PrintAfterEveryPair("bb-vectorize-debug-print-after-every-pair", |
| cl::init(false), cl::Hidden, |
| cl::desc("When debugging is enabled, dump the basic block after" |
| " every pair is fused")); |
| #endif |
| |
| STATISTIC(NumFusedOps, "Number of operations fused by bb-vectorize"); |
| |
| namespace { |
| struct BBVectorize : public BasicBlockPass { |
| static char ID; // Pass identification, replacement for typeid |
| |
| const VectorizeConfig Config; |
| |
| BBVectorize(const VectorizeConfig &C = VectorizeConfig()) |
| : BasicBlockPass(ID), Config(C) { |
| initializeBBVectorizePass(*PassRegistry::getPassRegistry()); |
| } |
| |
| BBVectorize(Pass *P, const VectorizeConfig &C) |
| : BasicBlockPass(ID), Config(C) { |
| AA = &P->getAnalysis<AliasAnalysis>(); |
| DT = &P->getAnalysis<DominatorTree>(); |
| SE = &P->getAnalysis<ScalarEvolution>(); |
| TD = P->getAnalysisIfAvailable<DataLayout>(); |
| TTI = IgnoreTargetInfo ? 0 : &P->getAnalysis<TargetTransformInfo>(); |
| } |
| |
| typedef std::pair<Value *, Value *> ValuePair; |
| typedef std::pair<ValuePair, int> ValuePairWithCost; |
| typedef std::pair<ValuePair, size_t> ValuePairWithDepth; |
| typedef std::pair<ValuePair, ValuePair> VPPair; // A ValuePair pair |
| typedef std::pair<VPPair, unsigned> VPPairWithType; |
| |
| AliasAnalysis *AA; |
| DominatorTree *DT; |
| ScalarEvolution *SE; |
| DataLayout *TD; |
| const TargetTransformInfo *TTI; |
| |
| // FIXME: const correct? |
| |
| bool vectorizePairs(BasicBlock &BB, bool NonPow2Len = false); |
| |
| bool getCandidatePairs(BasicBlock &BB, |
| BasicBlock::iterator &Start, |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &FixedOrderPairs, |
| DenseMap<ValuePair, int> &CandidatePairCostSavings, |
| std::vector<Value *> &PairableInsts, bool NonPow2Len); |
| |
| // FIXME: The current implementation does not account for pairs that |
| // are connected in multiple ways. For example: |
| // C1 = A1 / A2; C2 = A2 / A1 (which may be both direct and a swap) |
| enum PairConnectionType { |
| PairConnectionDirect, |
| PairConnectionSwap, |
| PairConnectionSplat |
| }; |
| |
| void computeConnectedPairs( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes); |
| |
| void buildDepMap(BasicBlock &BB, |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| std::vector<Value *> &PairableInsts, |
| DenseSet<ValuePair> &PairableInstUsers); |
| |
| void choosePairs(DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| DenseMap<ValuePair, int> &CandidatePairCostSavings, |
| std::vector<Value *> &PairableInsts, |
| DenseSet<ValuePair> &FixedOrderPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairDeps, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<Value *, Value *>& ChosenPairs); |
| |
| void fuseChosenPairs(BasicBlock &BB, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<Value *, Value *>& ChosenPairs, |
| DenseSet<ValuePair> &FixedOrderPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairDeps); |
| |
| |
| bool isInstVectorizable(Instruction *I, bool &IsSimpleLoadStore); |
| |
| bool areInstsCompatible(Instruction *I, Instruction *J, |
| bool IsSimpleLoadStore, bool NonPow2Len, |
| int &CostSavings, int &FixedOrder); |
| |
| bool trackUsesOfI(DenseSet<Value *> &Users, |
| AliasSetTracker &WriteSet, Instruction *I, |
| Instruction *J, bool UpdateUsers = true, |
| DenseSet<ValuePair> *LoadMoveSetPairs = 0); |
| |
| void computePairsConnectedTo( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes, |
| ValuePair P); |
| |
| bool pairsConflict(ValuePair P, ValuePair Q, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<ValuePair, std::vector<ValuePair> > |
| *PairableInstUserMap = 0, |
| DenseSet<VPPair> *PairableInstUserPairSet = 0); |
| |
| bool pairWillFormCycle(ValuePair P, |
| DenseMap<ValuePair, std::vector<ValuePair> > &PairableInstUsers, |
| DenseSet<ValuePair> &CurrentPairs); |
| |
| void pruneDAGFor( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<ValuePair, std::vector<ValuePair> > &PairableInstUserMap, |
| DenseSet<VPPair> &PairableInstUserPairSet, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseMap<ValuePair, size_t> &DAG, |
| DenseSet<ValuePair> &PrunedDAG, ValuePair J, |
| bool UseCycleCheck); |
| |
| void buildInitialDAGFor( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseMap<ValuePair, size_t> &DAG, ValuePair J); |
| |
| void findBestDAGFor( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| DenseMap<ValuePair, int> &CandidatePairCostSavings, |
| std::vector<Value *> &PairableInsts, |
| DenseSet<ValuePair> &FixedOrderPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairDeps, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<ValuePair, std::vector<ValuePair> > &PairableInstUserMap, |
| DenseSet<VPPair> &PairableInstUserPairSet, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseSet<ValuePair> &BestDAG, size_t &BestMaxDepth, |
| int &BestEffSize, Value *II, std::vector<Value *>&JJ, |
| bool UseCycleCheck); |
| |
| Value *getReplacementPointerInput(LLVMContext& Context, Instruction *I, |
| Instruction *J, unsigned o); |
| |
| void fillNewShuffleMask(LLVMContext& Context, Instruction *J, |
| unsigned MaskOffset, unsigned NumInElem, |
| unsigned NumInElem1, unsigned IdxOffset, |
| std::vector<Constant*> &Mask); |
| |
| Value *getReplacementShuffleMask(LLVMContext& Context, Instruction *I, |
| Instruction *J); |
| |
| bool expandIEChain(LLVMContext& Context, Instruction *I, Instruction *J, |
| unsigned o, Value *&LOp, unsigned numElemL, |
| Type *ArgTypeL, Type *ArgTypeR, bool IBeforeJ, |
| unsigned IdxOff = 0); |
| |
| Value *getReplacementInput(LLVMContext& Context, Instruction *I, |
| Instruction *J, unsigned o, bool IBeforeJ); |
| |
| void getReplacementInputsForPair(LLVMContext& Context, Instruction *I, |
| Instruction *J, SmallVector<Value *, 3> &ReplacedOperands, |
| bool IBeforeJ); |
| |
| void replaceOutputsOfPair(LLVMContext& Context, Instruction *I, |
| Instruction *J, Instruction *K, |
| Instruction *&InsertionPt, Instruction *&K1, |
| Instruction *&K2); |
| |
| void collectPairLoadMoveSet(BasicBlock &BB, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseMap<Value *, std::vector<Value *> > &LoadMoveSet, |
| DenseSet<ValuePair> &LoadMoveSetPairs, |
| Instruction *I); |
| |
| void collectLoadMoveSet(BasicBlock &BB, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseMap<Value *, std::vector<Value *> > &LoadMoveSet, |
| DenseSet<ValuePair> &LoadMoveSetPairs); |
| |
| bool canMoveUsesOfIAfterJ(BasicBlock &BB, |
| DenseSet<ValuePair> &LoadMoveSetPairs, |
| Instruction *I, Instruction *J); |
| |
| void moveUsesOfIAfterJ(BasicBlock &BB, |
| DenseSet<ValuePair> &LoadMoveSetPairs, |
| Instruction *&InsertionPt, |
| Instruction *I, Instruction *J); |
| |
| void combineMetadata(Instruction *K, const Instruction *J); |
| |
| bool vectorizeBB(BasicBlock &BB) { |
| if (!DT->isReachableFromEntry(&BB)) { |
| DEBUG(dbgs() << "BBV: skipping unreachable " << BB.getName() << |
| " in " << BB.getParent()->getName() << "\n"); |
| return false; |
| } |
| |
| DEBUG(if (TTI) dbgs() << "BBV: using target information\n"); |
| |
| bool changed = false; |
| // Iterate a sufficient number of times to merge types of size 1 bit, |
| // then 2 bits, then 4, etc. up to half of the target vector width of the |
| // target vector register. |
| unsigned n = 1; |
| for (unsigned v = 2; |
| (TTI || v <= Config.VectorBits) && |
| (!Config.MaxIter || n <= Config.MaxIter); |
| v *= 2, ++n) { |
| DEBUG(dbgs() << "BBV: fusing loop #" << n << |
| " for " << BB.getName() << " in " << |
| BB.getParent()->getName() << "...\n"); |
| if (vectorizePairs(BB)) |
| changed = true; |
| else |
| break; |
| } |
| |
| if (changed && !Pow2LenOnly) { |
| ++n; |
| for (; !Config.MaxIter || n <= Config.MaxIter; ++n) { |
| DEBUG(dbgs() << "BBV: fusing for non-2^n-length vectors loop #: " << |
| n << " for " << BB.getName() << " in " << |
| BB.getParent()->getName() << "...\n"); |
| if (!vectorizePairs(BB, true)) break; |
| } |
| } |
| |
| DEBUG(dbgs() << "BBV: done!\n"); |
| return changed; |
| } |
| |
| virtual bool runOnBasicBlock(BasicBlock &BB) { |
| AA = &getAnalysis<AliasAnalysis>(); |
| DT = &getAnalysis<DominatorTree>(); |
| SE = &getAnalysis<ScalarEvolution>(); |
| TD = getAnalysisIfAvailable<DataLayout>(); |
| TTI = IgnoreTargetInfo ? 0 : &getAnalysis<TargetTransformInfo>(); |
| |
| return vectorizeBB(BB); |
| } |
| |
| virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| BasicBlockPass::getAnalysisUsage(AU); |
| AU.addRequired<AliasAnalysis>(); |
| AU.addRequired<DominatorTree>(); |
| AU.addRequired<ScalarEvolution>(); |
| AU.addRequired<TargetTransformInfo>(); |
| AU.addPreserved<AliasAnalysis>(); |
| AU.addPreserved<DominatorTree>(); |
| AU.addPreserved<ScalarEvolution>(); |
| AU.setPreservesCFG(); |
| } |
| |
| static inline VectorType *getVecTypeForPair(Type *ElemTy, Type *Elem2Ty) { |
| assert(ElemTy->getScalarType() == Elem2Ty->getScalarType() && |
| "Cannot form vector from incompatible scalar types"); |
| Type *STy = ElemTy->getScalarType(); |
| |
| unsigned numElem; |
| if (VectorType *VTy = dyn_cast<VectorType>(ElemTy)) { |
| numElem = VTy->getNumElements(); |
| } else { |
| numElem = 1; |
| } |
| |
| if (VectorType *VTy = dyn_cast<VectorType>(Elem2Ty)) { |
| numElem += VTy->getNumElements(); |
| } else { |
| numElem += 1; |
| } |
| |
| return VectorType::get(STy, numElem); |
| } |
| |
| static inline void getInstructionTypes(Instruction *I, |
| Type *&T1, Type *&T2) { |
| if (StoreInst *SI = dyn_cast<StoreInst>(I)) { |
| // For stores, it is the value type, not the pointer type that matters |
| // because the value is what will come from a vector register. |
| |
| Value *IVal = SI->getValueOperand(); |
| T1 = IVal->getType(); |
| } else { |
| T1 = I->getType(); |
| } |
| |
| if (CastInst *CI = dyn_cast<CastInst>(I)) |
| T2 = CI->getSrcTy(); |
| else |
| T2 = T1; |
| |
| if (SelectInst *SI = dyn_cast<SelectInst>(I)) { |
| T2 = SI->getCondition()->getType(); |
| } else if (ShuffleVectorInst *SI = dyn_cast<ShuffleVectorInst>(I)) { |
| T2 = SI->getOperand(0)->getType(); |
| } else if (CmpInst *CI = dyn_cast<CmpInst>(I)) { |
| T2 = CI->getOperand(0)->getType(); |
| } |
| } |
| |
| // Returns the weight associated with the provided value. A chain of |
| // candidate pairs has a length given by the sum of the weights of its |
| // members (one weight per pair; the weight of each member of the pair |
| // is assumed to be the same). This length is then compared to the |
| // chain-length threshold to determine if a given chain is significant |
| // enough to be vectorized. The length is also used in comparing |
| // candidate chains where longer chains are considered to be better. |
| // Note: when this function returns 0, the resulting instructions are |
| // not actually fused. |
| inline size_t getDepthFactor(Value *V) { |
| // InsertElement and ExtractElement have a depth factor of zero. This is |
| // for two reasons: First, they cannot be usefully fused. Second, because |
| // the pass generates a lot of these, they can confuse the simple metric |
| // used to compare the dags in the next iteration. Thus, giving them a |
| // weight of zero allows the pass to essentially ignore them in |
| // subsequent iterations when looking for vectorization opportunities |
| // while still tracking dependency chains that flow through those |
| // instructions. |
| if (isa<InsertElementInst>(V) || isa<ExtractElementInst>(V)) |
| return 0; |
| |
| // Give a load or store half of the required depth so that load/store |
| // pairs will vectorize. |
| if (!Config.NoMemOpBoost && (isa<LoadInst>(V) || isa<StoreInst>(V))) |
| return Config.ReqChainDepth/2; |
| |
| return 1; |
| } |
| |
| // Returns the cost of the provided instruction using TTI. |
| // This does not handle loads and stores. |
| unsigned getInstrCost(unsigned Opcode, Type *T1, Type *T2) { |
| switch (Opcode) { |
| default: break; |
| case Instruction::GetElementPtr: |
| // We mark this instruction as zero-cost because scalar GEPs are usually |
| // lowered to the intruction addressing mode. At the moment we don't |
| // generate vector GEPs. |
| return 0; |
| case Instruction::Br: |
| return TTI->getCFInstrCost(Opcode); |
| case Instruction::PHI: |
| return 0; |
| case Instruction::Add: |
| case Instruction::FAdd: |
| case Instruction::Sub: |
| case Instruction::FSub: |
| case Instruction::Mul: |
| case Instruction::FMul: |
| case Instruction::UDiv: |
| case Instruction::SDiv: |
| case Instruction::FDiv: |
| case Instruction::URem: |
| case Instruction::SRem: |
| case Instruction::FRem: |
| case Instruction::Shl: |
| case Instruction::LShr: |
| case Instruction::AShr: |
| case Instruction::And: |
| case Instruction::Or: |
| case Instruction::Xor: |
| return TTI->getArithmeticInstrCost(Opcode, T1); |
| case Instruction::Select: |
| case Instruction::ICmp: |
| case Instruction::FCmp: |
| return TTI->getCmpSelInstrCost(Opcode, T1, T2); |
| case Instruction::ZExt: |
| case Instruction::SExt: |
| case Instruction::FPToUI: |
| case Instruction::FPToSI: |
| case Instruction::FPExt: |
| case Instruction::PtrToInt: |
| case Instruction::IntToPtr: |
| case Instruction::SIToFP: |
| case Instruction::UIToFP: |
| case Instruction::Trunc: |
| case Instruction::FPTrunc: |
| case Instruction::BitCast: |
| case Instruction::ShuffleVector: |
| return TTI->getCastInstrCost(Opcode, T1, T2); |
| } |
| |
| return 1; |
| } |
| |
| // This determines the relative offset of two loads or stores, returning |
| // true if the offset could be determined to be some constant value. |
| // For example, if OffsetInElmts == 1, then J accesses the memory directly |
| // after I; if OffsetInElmts == -1 then I accesses the memory |
| // directly after J. |
| bool getPairPtrInfo(Instruction *I, Instruction *J, |
| Value *&IPtr, Value *&JPtr, unsigned &IAlignment, unsigned &JAlignment, |
| unsigned &IAddressSpace, unsigned &JAddressSpace, |
| int64_t &OffsetInElmts, bool ComputeOffset = true) { |
| OffsetInElmts = 0; |
| if (LoadInst *LI = dyn_cast<LoadInst>(I)) { |
| LoadInst *LJ = cast<LoadInst>(J); |
| IPtr = LI->getPointerOperand(); |
| JPtr = LJ->getPointerOperand(); |
| IAlignment = LI->getAlignment(); |
| JAlignment = LJ->getAlignment(); |
| IAddressSpace = LI->getPointerAddressSpace(); |
| JAddressSpace = LJ->getPointerAddressSpace(); |
| } else { |
| StoreInst *SI = cast<StoreInst>(I), *SJ = cast<StoreInst>(J); |
| IPtr = SI->getPointerOperand(); |
| JPtr = SJ->getPointerOperand(); |
| IAlignment = SI->getAlignment(); |
| JAlignment = SJ->getAlignment(); |
| IAddressSpace = SI->getPointerAddressSpace(); |
| JAddressSpace = SJ->getPointerAddressSpace(); |
| } |
| |
| if (!ComputeOffset) |
| return true; |
| |
| const SCEV *IPtrSCEV = SE->getSCEV(IPtr); |
| const SCEV *JPtrSCEV = SE->getSCEV(JPtr); |
| |
| // If this is a trivial offset, then we'll get something like |
| // 1*sizeof(type). With target data, which we need anyway, this will get |
| // constant folded into a number. |
| const SCEV *OffsetSCEV = SE->getMinusSCEV(JPtrSCEV, IPtrSCEV); |
| if (const SCEVConstant *ConstOffSCEV = |
| dyn_cast<SCEVConstant>(OffsetSCEV)) { |
| ConstantInt *IntOff = ConstOffSCEV->getValue(); |
| int64_t Offset = IntOff->getSExtValue(); |
| |
| Type *VTy = cast<PointerType>(IPtr->getType())->getElementType(); |
| int64_t VTyTSS = (int64_t) TD->getTypeStoreSize(VTy); |
| |
| Type *VTy2 = cast<PointerType>(JPtr->getType())->getElementType(); |
| if (VTy != VTy2 && Offset < 0) { |
| int64_t VTy2TSS = (int64_t) TD->getTypeStoreSize(VTy2); |
| OffsetInElmts = Offset/VTy2TSS; |
| return (abs64(Offset) % VTy2TSS) == 0; |
| } |
| |
| OffsetInElmts = Offset/VTyTSS; |
| return (abs64(Offset) % VTyTSS) == 0; |
| } |
| |
| return false; |
| } |
| |
| // Returns true if the provided CallInst represents an intrinsic that can |
| // be vectorized. |
| bool isVectorizableIntrinsic(CallInst* I) { |
| Function *F = I->getCalledFunction(); |
| if (!F) return false; |
| |
| Intrinsic::ID IID = (Intrinsic::ID) F->getIntrinsicID(); |
| if (!IID) return false; |
| |
| switch(IID) { |
| default: |
| return false; |
| case Intrinsic::sqrt: |
| case Intrinsic::powi: |
| case Intrinsic::sin: |
| case Intrinsic::cos: |
| case Intrinsic::log: |
| case Intrinsic::log2: |
| case Intrinsic::log10: |
| case Intrinsic::exp: |
| case Intrinsic::exp2: |
| case Intrinsic::pow: |
| return Config.VectorizeMath; |
| case Intrinsic::fma: |
| case Intrinsic::fmuladd: |
| return Config.VectorizeFMA; |
| } |
| } |
| |
| bool isPureIEChain(InsertElementInst *IE) { |
| InsertElementInst *IENext = IE; |
| do { |
| if (!isa<UndefValue>(IENext->getOperand(0)) && |
| !isa<InsertElementInst>(IENext->getOperand(0))) { |
| return false; |
| } |
| } while ((IENext = |
| dyn_cast<InsertElementInst>(IENext->getOperand(0)))); |
| |
| return true; |
| } |
| }; |
| |
| // This function implements one vectorization iteration on the provided |
| // basic block. It returns true if the block is changed. |
| bool BBVectorize::vectorizePairs(BasicBlock &BB, bool NonPow2Len) { |
| bool ShouldContinue; |
| BasicBlock::iterator Start = BB.getFirstInsertionPt(); |
| |
| std::vector<Value *> AllPairableInsts; |
| DenseMap<Value *, Value *> AllChosenPairs; |
| DenseSet<ValuePair> AllFixedOrderPairs; |
| DenseMap<VPPair, unsigned> AllPairConnectionTypes; |
| DenseMap<ValuePair, std::vector<ValuePair> > AllConnectedPairs, |
| AllConnectedPairDeps; |
| |
| do { |
| std::vector<Value *> PairableInsts; |
| DenseMap<Value *, std::vector<Value *> > CandidatePairs; |
| DenseSet<ValuePair> FixedOrderPairs; |
| DenseMap<ValuePair, int> CandidatePairCostSavings; |
| ShouldContinue = getCandidatePairs(BB, Start, CandidatePairs, |
| FixedOrderPairs, |
| CandidatePairCostSavings, |
| PairableInsts, NonPow2Len); |
| if (PairableInsts.empty()) continue; |
| |
| // Build the candidate pair set for faster lookups. |
| DenseSet<ValuePair> CandidatePairsSet; |
| for (DenseMap<Value *, std::vector<Value *> >::iterator I = |
| CandidatePairs.begin(), E = CandidatePairs.end(); I != E; ++I) |
| for (std::vector<Value *>::iterator J = I->second.begin(), |
| JE = I->second.end(); J != JE; ++J) |
| CandidatePairsSet.insert(ValuePair(I->first, *J)); |
| |
| // Now we have a map of all of the pairable instructions and we need to |
| // select the best possible pairing. A good pairing is one such that the |
| // users of the pair are also paired. This defines a (directed) forest |
| // over the pairs such that two pairs are connected iff the second pair |
| // uses the first. |
| |
| // Note that it only matters that both members of the second pair use some |
| // element of the first pair (to allow for splatting). |
| |
| DenseMap<ValuePair, std::vector<ValuePair> > ConnectedPairs, |
| ConnectedPairDeps; |
| DenseMap<VPPair, unsigned> PairConnectionTypes; |
| computeConnectedPairs(CandidatePairs, CandidatePairsSet, |
| PairableInsts, ConnectedPairs, PairConnectionTypes); |
| if (ConnectedPairs.empty()) continue; |
| |
| for (DenseMap<ValuePair, std::vector<ValuePair> >::iterator |
| I = ConnectedPairs.begin(), IE = ConnectedPairs.end(); |
| I != IE; ++I) |
| for (std::vector<ValuePair>::iterator J = I->second.begin(), |
| JE = I->second.end(); J != JE; ++J) |
| ConnectedPairDeps[*J].push_back(I->first); |
| |
| // Build the pairable-instruction dependency map |
| DenseSet<ValuePair> PairableInstUsers; |
| buildDepMap(BB, CandidatePairs, PairableInsts, PairableInstUsers); |
| |
| // There is now a graph of the connected pairs. For each variable, pick |
| // the pairing with the largest dag meeting the depth requirement on at |
| // least one branch. Then select all pairings that are part of that dag |
| // and remove them from the list of available pairings and pairable |
| // variables. |
| |
| DenseMap<Value *, Value *> ChosenPairs; |
| choosePairs(CandidatePairs, CandidatePairsSet, |
| CandidatePairCostSavings, |
| PairableInsts, FixedOrderPairs, PairConnectionTypes, |
| ConnectedPairs, ConnectedPairDeps, |
| PairableInstUsers, ChosenPairs); |
| |
| if (ChosenPairs.empty()) continue; |
| AllPairableInsts.insert(AllPairableInsts.end(), PairableInsts.begin(), |
| PairableInsts.end()); |
| AllChosenPairs.insert(ChosenPairs.begin(), ChosenPairs.end()); |
| |
| // Only for the chosen pairs, propagate information on fixed-order pairs, |
| // pair connections, and their types to the data structures used by the |
| // pair fusion procedures. |
| for (DenseMap<Value *, Value *>::iterator I = ChosenPairs.begin(), |
| IE = ChosenPairs.end(); I != IE; ++I) { |
| if (FixedOrderPairs.count(*I)) |
| AllFixedOrderPairs.insert(*I); |
| else if (FixedOrderPairs.count(ValuePair(I->second, I->first))) |
| AllFixedOrderPairs.insert(ValuePair(I->second, I->first)); |
| |
| for (DenseMap<Value *, Value *>::iterator J = ChosenPairs.begin(); |
| J != IE; ++J) { |
| DenseMap<VPPair, unsigned>::iterator K = |
| PairConnectionTypes.find(VPPair(*I, *J)); |
| if (K != PairConnectionTypes.end()) { |
| AllPairConnectionTypes.insert(*K); |
| } else { |
| K = PairConnectionTypes.find(VPPair(*J, *I)); |
| if (K != PairConnectionTypes.end()) |
| AllPairConnectionTypes.insert(*K); |
| } |
| } |
| } |
| |
| for (DenseMap<ValuePair, std::vector<ValuePair> >::iterator |
| I = ConnectedPairs.begin(), IE = ConnectedPairs.end(); |
| I != IE; ++I) |
| for (std::vector<ValuePair>::iterator J = I->second.begin(), |
| JE = I->second.end(); J != JE; ++J) |
| if (AllPairConnectionTypes.count(VPPair(I->first, *J))) { |
| AllConnectedPairs[I->first].push_back(*J); |
| AllConnectedPairDeps[*J].push_back(I->first); |
| } |
| } while (ShouldContinue); |
| |
| if (AllChosenPairs.empty()) return false; |
| NumFusedOps += AllChosenPairs.size(); |
| |
| // A set of pairs has now been selected. It is now necessary to replace the |
| // paired instructions with vector instructions. For this procedure each |
| // operand must be replaced with a vector operand. This vector is formed |
| // by using build_vector on the old operands. The replaced values are then |
| // replaced with a vector_extract on the result. Subsequent optimization |
| // passes should coalesce the build/extract combinations. |
| |
| fuseChosenPairs(BB, AllPairableInsts, AllChosenPairs, AllFixedOrderPairs, |
| AllPairConnectionTypes, |
| AllConnectedPairs, AllConnectedPairDeps); |
| |
| // It is important to cleanup here so that future iterations of this |
| // function have less work to do. |
| (void) SimplifyInstructionsInBlock(&BB, TD, AA->getTargetLibraryInfo()); |
| return true; |
| } |
| |
| // This function returns true if the provided instruction is capable of being |
| // fused into a vector instruction. This determination is based only on the |
| // type and other attributes of the instruction. |
| bool BBVectorize::isInstVectorizable(Instruction *I, |
| bool &IsSimpleLoadStore) { |
| IsSimpleLoadStore = false; |
| |
| if (CallInst *C = dyn_cast<CallInst>(I)) { |
| if (!isVectorizableIntrinsic(C)) |
| return false; |
| } else if (LoadInst *L = dyn_cast<LoadInst>(I)) { |
| // Vectorize simple loads if possbile: |
| IsSimpleLoadStore = L->isSimple(); |
| if (!IsSimpleLoadStore || !Config.VectorizeMemOps) |
| return false; |
| } else if (StoreInst *S = dyn_cast<StoreInst>(I)) { |
| // Vectorize simple stores if possbile: |
| IsSimpleLoadStore = S->isSimple(); |
| if (!IsSimpleLoadStore || !Config.VectorizeMemOps) |
| return false; |
| } else if (CastInst *C = dyn_cast<CastInst>(I)) { |
| // We can vectorize casts, but not casts of pointer types, etc. |
| if (!Config.VectorizeCasts) |
| return false; |
| |
| Type *SrcTy = C->getSrcTy(); |
| if (!SrcTy->isSingleValueType()) |
| return false; |
| |
| Type *DestTy = C->getDestTy(); |
| if (!DestTy->isSingleValueType()) |
| return false; |
| } else if (isa<SelectInst>(I)) { |
| if (!Config.VectorizeSelect) |
| return false; |
| } else if (isa<CmpInst>(I)) { |
| if (!Config.VectorizeCmp) |
| return false; |
| } else if (GetElementPtrInst *G = dyn_cast<GetElementPtrInst>(I)) { |
| if (!Config.VectorizeGEP) |
| return false; |
| |
| // Currently, vector GEPs exist only with one index. |
| if (G->getNumIndices() != 1) |
| return false; |
| } else if (!(I->isBinaryOp() || isa<ShuffleVectorInst>(I) || |
| isa<ExtractElementInst>(I) || isa<InsertElementInst>(I))) { |
| return false; |
| } |
| |
| // We can't vectorize memory operations without target data |
| if (TD == 0 && IsSimpleLoadStore) |
| return false; |
| |
| Type *T1, *T2; |
| getInstructionTypes(I, T1, T2); |
| |
| // Not every type can be vectorized... |
| if (!(VectorType::isValidElementType(T1) || T1->isVectorTy()) || |
| !(VectorType::isValidElementType(T2) || T2->isVectorTy())) |
| return false; |
| |
| if (T1->getScalarSizeInBits() == 1) { |
| if (!Config.VectorizeBools) |
| return false; |
| } else { |
| if (!Config.VectorizeInts && T1->isIntOrIntVectorTy()) |
| return false; |
| } |
| |
| if (T2->getScalarSizeInBits() == 1) { |
| if (!Config.VectorizeBools) |
| return false; |
| } else { |
| if (!Config.VectorizeInts && T2->isIntOrIntVectorTy()) |
| return false; |
| } |
| |
| if (!Config.VectorizeFloats |
| && (T1->isFPOrFPVectorTy() || T2->isFPOrFPVectorTy())) |
| return false; |
| |
| // Don't vectorize target-specific types. |
| if (T1->isX86_FP80Ty() || T1->isPPC_FP128Ty() || T1->isX86_MMXTy()) |
| return false; |
| if (T2->isX86_FP80Ty() || T2->isPPC_FP128Ty() || T2->isX86_MMXTy()) |
| return false; |
| |
| if ((!Config.VectorizePointers || TD == 0) && |
| (T1->getScalarType()->isPointerTy() || |
| T2->getScalarType()->isPointerTy())) |
| return false; |
| |
| if (!TTI && (T1->getPrimitiveSizeInBits() >= Config.VectorBits || |
| T2->getPrimitiveSizeInBits() >= Config.VectorBits)) |
| return false; |
| |
| return true; |
| } |
| |
| // This function returns true if the two provided instructions are compatible |
| // (meaning that they can be fused into a vector instruction). This assumes |
| // that I has already been determined to be vectorizable and that J is not |
| // in the use dag of I. |
| bool BBVectorize::areInstsCompatible(Instruction *I, Instruction *J, |
| bool IsSimpleLoadStore, bool NonPow2Len, |
| int &CostSavings, int &FixedOrder) { |
| DEBUG(if (DebugInstructionExamination) dbgs() << "BBV: looking at " << *I << |
| " <-> " << *J << "\n"); |
| |
| CostSavings = 0; |
| FixedOrder = 0; |
| |
| // Loads and stores can be merged if they have different alignments, |
| // but are otherwise the same. |
| if (!J->isSameOperationAs(I, Instruction::CompareIgnoringAlignment | |
| (NonPow2Len ? Instruction::CompareUsingScalarTypes : 0))) |
| return false; |
| |
| Type *IT1, *IT2, *JT1, *JT2; |
| getInstructionTypes(I, IT1, IT2); |
| getInstructionTypes(J, JT1, JT2); |
| unsigned MaxTypeBits = std::max( |
| IT1->getPrimitiveSizeInBits() + JT1->getPrimitiveSizeInBits(), |
| IT2->getPrimitiveSizeInBits() + JT2->getPrimitiveSizeInBits()); |
| if (!TTI && MaxTypeBits > Config.VectorBits) |
| return false; |
| |
| // FIXME: handle addsub-type operations! |
| |
| if (IsSimpleLoadStore) { |
| Value *IPtr, *JPtr; |
| unsigned IAlignment, JAlignment, IAddressSpace, JAddressSpace; |
| int64_t OffsetInElmts = 0; |
| if (getPairPtrInfo(I, J, IPtr, JPtr, IAlignment, JAlignment, |
| IAddressSpace, JAddressSpace, |
| OffsetInElmts) && abs64(OffsetInElmts) == 1) { |
| FixedOrder = (int) OffsetInElmts; |
| unsigned BottomAlignment = IAlignment; |
| if (OffsetInElmts < 0) BottomAlignment = JAlignment; |
| |
| Type *aTypeI = isa<StoreInst>(I) ? |
| cast<StoreInst>(I)->getValueOperand()->getType() : I->getType(); |
| Type *aTypeJ = isa<StoreInst>(J) ? |
| cast<StoreInst>(J)->getValueOperand()->getType() : J->getType(); |
| Type *VType = getVecTypeForPair(aTypeI, aTypeJ); |
| |
| if (Config.AlignedOnly) { |
| // An aligned load or store is possible only if the instruction |
| // with the lower offset has an alignment suitable for the |
| // vector type. |
| |
| unsigned VecAlignment = TD->getPrefTypeAlignment(VType); |
| if (BottomAlignment < VecAlignment) |
| return false; |
| } |
| |
| if (TTI) { |
| unsigned ICost = TTI->getMemoryOpCost(I->getOpcode(), aTypeI, |
| IAlignment, IAddressSpace); |
| unsigned JCost = TTI->getMemoryOpCost(J->getOpcode(), aTypeJ, |
| JAlignment, JAddressSpace); |
| unsigned VCost = TTI->getMemoryOpCost(I->getOpcode(), VType, |
| BottomAlignment, |
| IAddressSpace); |
| |
| ICost += TTI->getAddressComputationCost(aTypeI); |
| JCost += TTI->getAddressComputationCost(aTypeJ); |
| VCost += TTI->getAddressComputationCost(VType); |
| |
| if (VCost > ICost + JCost) |
| return false; |
| |
| // We don't want to fuse to a type that will be split, even |
| // if the two input types will also be split and there is no other |
| // associated cost. |
| unsigned VParts = TTI->getNumberOfParts(VType); |
| if (VParts > 1) |
| return false; |
| else if (!VParts && VCost == ICost + JCost) |
| return false; |
| |
| CostSavings = ICost + JCost - VCost; |
| } |
| } else { |
| return false; |
| } |
| } else if (TTI) { |
| unsigned ICost = getInstrCost(I->getOpcode(), IT1, IT2); |
| unsigned JCost = getInstrCost(J->getOpcode(), JT1, JT2); |
| Type *VT1 = getVecTypeForPair(IT1, JT1), |
| *VT2 = getVecTypeForPair(IT2, JT2); |
| |
| // Note that this procedure is incorrect for insert and extract element |
| // instructions (because combining these often results in a shuffle), |
| // but this cost is ignored (because insert and extract element |
| // instructions are assigned a zero depth factor and are not really |
| // fused in general). |
| unsigned VCost = getInstrCost(I->getOpcode(), VT1, VT2); |
| |
| if (VCost > ICost + JCost) |
| return false; |
| |
| // We don't want to fuse to a type that will be split, even |
| // if the two input types will also be split and there is no other |
| // associated cost. |
| unsigned VParts1 = TTI->getNumberOfParts(VT1), |
| VParts2 = TTI->getNumberOfParts(VT2); |
| if (VParts1 > 1 || VParts2 > 1) |
| return false; |
| else if ((!VParts1 || !VParts2) && VCost == ICost + JCost) |
| return false; |
| |
| CostSavings = ICost + JCost - VCost; |
| } |
| |
| // The powi intrinsic is special because only the first argument is |
| // vectorized, the second arguments must be equal. |
| CallInst *CI = dyn_cast<CallInst>(I); |
| Function *FI; |
| if (CI && (FI = CI->getCalledFunction())) { |
| Intrinsic::ID IID = (Intrinsic::ID) FI->getIntrinsicID(); |
| if (IID == Intrinsic::powi) { |
| Value *A1I = CI->getArgOperand(1), |
| *A1J = cast<CallInst>(J)->getArgOperand(1); |
| const SCEV *A1ISCEV = SE->getSCEV(A1I), |
| *A1JSCEV = SE->getSCEV(A1J); |
| return (A1ISCEV == A1JSCEV); |
| } |
| |
| if (IID && TTI) { |
| SmallVector<Type*, 4> Tys; |
| for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) |
| Tys.push_back(CI->getArgOperand(i)->getType()); |
| unsigned ICost = TTI->getIntrinsicInstrCost(IID, IT1, Tys); |
| |
| Tys.clear(); |
| CallInst *CJ = cast<CallInst>(J); |
| for (unsigned i = 0, ie = CJ->getNumArgOperands(); i != ie; ++i) |
| Tys.push_back(CJ->getArgOperand(i)->getType()); |
| unsigned JCost = TTI->getIntrinsicInstrCost(IID, JT1, Tys); |
| |
| Tys.clear(); |
| assert(CI->getNumArgOperands() == CJ->getNumArgOperands() && |
| "Intrinsic argument counts differ"); |
| for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) { |
| if (IID == Intrinsic::powi && i == 1) |
| Tys.push_back(CI->getArgOperand(i)->getType()); |
| else |
| Tys.push_back(getVecTypeForPair(CI->getArgOperand(i)->getType(), |
| CJ->getArgOperand(i)->getType())); |
| } |
| |
| Type *RetTy = getVecTypeForPair(IT1, JT1); |
| unsigned VCost = TTI->getIntrinsicInstrCost(IID, RetTy, Tys); |
| |
| if (VCost > ICost + JCost) |
| return false; |
| |
| // We don't want to fuse to a type that will be split, even |
| // if the two input types will also be split and there is no other |
| // associated cost. |
| unsigned RetParts = TTI->getNumberOfParts(RetTy); |
| if (RetParts > 1) |
| return false; |
| else if (!RetParts && VCost == ICost + JCost) |
| return false; |
| |
| for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) { |
| if (!Tys[i]->isVectorTy()) |
| continue; |
| |
| unsigned NumParts = TTI->getNumberOfParts(Tys[i]); |
| if (NumParts > 1) |
| return false; |
| else if (!NumParts && VCost == ICost + JCost) |
| return false; |
| } |
| |
| CostSavings = ICost + JCost - VCost; |
| } |
| } |
| |
| return true; |
| } |
| |
| // Figure out whether or not J uses I and update the users and write-set |
| // structures associated with I. Specifically, Users represents the set of |
| // instructions that depend on I. WriteSet represents the set |
| // of memory locations that are dependent on I. If UpdateUsers is true, |
| // and J uses I, then Users is updated to contain J and WriteSet is updated |
| // to contain any memory locations to which J writes. The function returns |
| // true if J uses I. By default, alias analysis is used to determine |
| // whether J reads from memory that overlaps with a location in WriteSet. |
| // If LoadMoveSet is not null, then it is a previously-computed map |
| // where the key is the memory-based user instruction and the value is |
| // the instruction to be compared with I. So, if LoadMoveSet is provided, |
| // then the alias analysis is not used. This is necessary because this |
| // function is called during the process of moving instructions during |
| // vectorization and the results of the alias analysis are not stable during |
| // that process. |
| bool BBVectorize::trackUsesOfI(DenseSet<Value *> &Users, |
| AliasSetTracker &WriteSet, Instruction *I, |
| Instruction *J, bool UpdateUsers, |
| DenseSet<ValuePair> *LoadMoveSetPairs) { |
| bool UsesI = false; |
| |
| // This instruction may already be marked as a user due, for example, to |
| // being a member of a selected pair. |
| if (Users.count(J)) |
| UsesI = true; |
| |
| if (!UsesI) |
| for (User::op_iterator JU = J->op_begin(), JE = J->op_end(); |
| JU != JE; ++JU) { |
| Value *V = *JU; |
| if (I == V || Users.count(V)) { |
| UsesI = true; |
| break; |
| } |
| } |
| if (!UsesI && J->mayReadFromMemory()) { |
| if (LoadMoveSetPairs) { |
| UsesI = LoadMoveSetPairs->count(ValuePair(J, I)); |
| } else { |
| for (AliasSetTracker::iterator W = WriteSet.begin(), |
| WE = WriteSet.end(); W != WE; ++W) { |
| if (W->aliasesUnknownInst(J, *AA)) { |
| UsesI = true; |
| break; |
| } |
| } |
| } |
| } |
| |
| if (UsesI && UpdateUsers) { |
| if (J->mayWriteToMemory()) WriteSet.add(J); |
| Users.insert(J); |
| } |
| |
| return UsesI; |
| } |
| |
| // This function iterates over all instruction pairs in the provided |
| // basic block and collects all candidate pairs for vectorization. |
| bool BBVectorize::getCandidatePairs(BasicBlock &BB, |
| BasicBlock::iterator &Start, |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &FixedOrderPairs, |
| DenseMap<ValuePair, int> &CandidatePairCostSavings, |
| std::vector<Value *> &PairableInsts, bool NonPow2Len) { |
| size_t TotalPairs = 0; |
| BasicBlock::iterator E = BB.end(); |
| if (Start == E) return false; |
| |
| bool ShouldContinue = false, IAfterStart = false; |
| for (BasicBlock::iterator I = Start++; I != E; ++I) { |
| if (I == Start) IAfterStart = true; |
| |
| bool IsSimpleLoadStore; |
| if (!isInstVectorizable(I, IsSimpleLoadStore)) continue; |
| |
| // Look for an instruction with which to pair instruction *I... |
| DenseSet<Value *> Users; |
| AliasSetTracker WriteSet(*AA); |
| bool JAfterStart = IAfterStart; |
| BasicBlock::iterator J = llvm::next(I); |
| for (unsigned ss = 0; J != E && ss <= Config.SearchLimit; ++J, ++ss) { |
| if (J == Start) JAfterStart = true; |
| |
| // Determine if J uses I, if so, exit the loop. |
| bool UsesI = trackUsesOfI(Users, WriteSet, I, J, !Config.FastDep); |
| if (Config.FastDep) { |
| // Note: For this heuristic to be effective, independent operations |
| // must tend to be intermixed. This is likely to be true from some |
| // kinds of grouped loop unrolling (but not the generic LLVM pass), |
| // but otherwise may require some kind of reordering pass. |
| |
| // When using fast dependency analysis, |
| // stop searching after first use: |
| if (UsesI) break; |
| } else { |
| if (UsesI) continue; |
| } |
| |
| // J does not use I, and comes before the first use of I, so it can be |
| // merged with I if the instructions are compatible. |
| int CostSavings, FixedOrder; |
| if (!areInstsCompatible(I, J, IsSimpleLoadStore, NonPow2Len, |
| CostSavings, FixedOrder)) continue; |
| |
| // J is a candidate for merging with I. |
| if (!PairableInsts.size() || |
| PairableInsts[PairableInsts.size()-1] != I) { |
| PairableInsts.push_back(I); |
| } |
| |
| CandidatePairs[I].push_back(J); |
| ++TotalPairs; |
| if (TTI) |
| CandidatePairCostSavings.insert(ValuePairWithCost(ValuePair(I, J), |
| CostSavings)); |
| |
| if (FixedOrder == 1) |
| FixedOrderPairs.insert(ValuePair(I, J)); |
| else if (FixedOrder == -1) |
| FixedOrderPairs.insert(ValuePair(J, I)); |
| |
| // The next call to this function must start after the last instruction |
| // selected during this invocation. |
| if (JAfterStart) { |
| Start = llvm::next(J); |
| IAfterStart = JAfterStart = false; |
| } |
| |
| DEBUG(if (DebugCandidateSelection) dbgs() << "BBV: candidate pair " |
| << *I << " <-> " << *J << " (cost savings: " << |
| CostSavings << ")\n"); |
| |
| // If we have already found too many pairs, break here and this function |
| // will be called again starting after the last instruction selected |
| // during this invocation. |
| if (PairableInsts.size() >= Config.MaxInsts || |
| TotalPairs >= Config.MaxPairs) { |
| ShouldContinue = true; |
| break; |
| } |
| } |
| |
| if (ShouldContinue) |
| break; |
| } |
| |
| DEBUG(dbgs() << "BBV: found " << PairableInsts.size() |
| << " instructions with candidate pairs\n"); |
| |
| return ShouldContinue; |
| } |
| |
| // Finds candidate pairs connected to the pair P = <PI, PJ>. This means that |
| // it looks for pairs such that both members have an input which is an |
| // output of PI or PJ. |
| void BBVectorize::computePairsConnectedTo( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes, |
| ValuePair P) { |
| StoreInst *SI, *SJ; |
| |
| // For each possible pairing for this variable, look at the uses of |
| // the first value... |
| for (Value::use_iterator I = P.first->use_begin(), |
| E = P.first->use_end(); I != E; ++I) { |
| if (isa<LoadInst>(*I)) { |
| // A pair cannot be connected to a load because the load only takes one |
| // operand (the address) and it is a scalar even after vectorization. |
| continue; |
| } else if ((SI = dyn_cast<StoreInst>(*I)) && |
| P.first == SI->getPointerOperand()) { |
| // Similarly, a pair cannot be connected to a store through its |
| // pointer operand. |
| continue; |
| } |
| |
| // For each use of the first variable, look for uses of the second |
| // variable... |
| for (Value::use_iterator J = P.second->use_begin(), |
| E2 = P.second->use_end(); J != E2; ++J) { |
| if ((SJ = dyn_cast<StoreInst>(*J)) && |
| P.second == SJ->getPointerOperand()) |
| continue; |
| |
| // Look for <I, J>: |
| if (CandidatePairsSet.count(ValuePair(*I, *J))) { |
| VPPair VP(P, ValuePair(*I, *J)); |
| ConnectedPairs[VP.first].push_back(VP.second); |
| PairConnectionTypes.insert(VPPairWithType(VP, PairConnectionDirect)); |
| } |
| |
| // Look for <J, I>: |
| if (CandidatePairsSet.count(ValuePair(*J, *I))) { |
| VPPair VP(P, ValuePair(*J, *I)); |
| ConnectedPairs[VP.first].push_back(VP.second); |
| PairConnectionTypes.insert(VPPairWithType(VP, PairConnectionSwap)); |
| } |
| } |
| |
| if (Config.SplatBreaksChain) continue; |
| // Look for cases where just the first value in the pair is used by |
| // both members of another pair (splatting). |
| for (Value::use_iterator J = P.first->use_begin(); J != E; ++J) { |
| if ((SJ = dyn_cast<StoreInst>(*J)) && |
| P.first == SJ->getPointerOperand()) |
| continue; |
| |
| if (CandidatePairsSet.count(ValuePair(*I, *J))) { |
| VPPair VP(P, ValuePair(*I, *J)); |
| ConnectedPairs[VP.first].push_back(VP.second); |
| PairConnectionTypes.insert(VPPairWithType(VP, PairConnectionSplat)); |
| } |
| } |
| } |
| |
| if (Config.SplatBreaksChain) return; |
| // Look for cases where just the second value in the pair is used by |
| // both members of another pair (splatting). |
| for (Value::use_iterator I = P.second->use_begin(), |
| E = P.second->use_end(); I != E; ++I) { |
| if (isa<LoadInst>(*I)) |
| continue; |
| else if ((SI = dyn_cast<StoreInst>(*I)) && |
| P.second == SI->getPointerOperand()) |
| continue; |
| |
| for (Value::use_iterator J = P.second->use_begin(); J != E; ++J) { |
| if ((SJ = dyn_cast<StoreInst>(*J)) && |
| P.second == SJ->getPointerOperand()) |
| continue; |
| |
| if (CandidatePairsSet.count(ValuePair(*I, *J))) { |
| VPPair VP(P, ValuePair(*I, *J)); |
| ConnectedPairs[VP.first].push_back(VP.second); |
| PairConnectionTypes.insert(VPPairWithType(VP, PairConnectionSplat)); |
| } |
| } |
| } |
| } |
| |
| // This function figures out which pairs are connected. Two pairs are |
| // connected if some output of the first pair forms an input to both members |
| // of the second pair. |
| void BBVectorize::computeConnectedPairs( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes) { |
| for (std::vector<Value *>::iterator PI = PairableInsts.begin(), |
| PE = PairableInsts.end(); PI != PE; ++PI) { |
| DenseMap<Value *, std::vector<Value *> >::iterator PP = |
| CandidatePairs.find(*PI); |
| if (PP == CandidatePairs.end()) |
| continue; |
| |
| for (std::vector<Value *>::iterator P = PP->second.begin(), |
| E = PP->second.end(); P != E; ++P) |
| computePairsConnectedTo(CandidatePairs, CandidatePairsSet, |
| PairableInsts, ConnectedPairs, |
| PairConnectionTypes, ValuePair(*PI, *P)); |
| } |
| |
| DEBUG(size_t TotalPairs = 0; |
| for (DenseMap<ValuePair, std::vector<ValuePair> >::iterator I = |
| ConnectedPairs.begin(), IE = ConnectedPairs.end(); I != IE; ++I) |
| TotalPairs += I->second.size(); |
| dbgs() << "BBV: found " << TotalPairs |
| << " pair connections.\n"); |
| } |
| |
| // This function builds a set of use tuples such that <A, B> is in the set |
| // if B is in the use dag of A. If B is in the use dag of A, then B |
| // depends on the output of A. |
| void BBVectorize::buildDepMap( |
| BasicBlock &BB, |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| std::vector<Value *> &PairableInsts, |
| DenseSet<ValuePair> &PairableInstUsers) { |
| DenseSet<Value *> IsInPair; |
| for (DenseMap<Value *, std::vector<Value *> >::iterator C = |
| CandidatePairs.begin(), E = CandidatePairs.end(); C != E; ++C) { |
| IsInPair.insert(C->first); |
| IsInPair.insert(C->second.begin(), C->second.end()); |
| } |
| |
| // Iterate through the basic block, recording all users of each |
| // pairable instruction. |
| |
| BasicBlock::iterator E = BB.end(), EL = |
| BasicBlock::iterator(cast<Instruction>(PairableInsts.back())); |
| for (BasicBlock::iterator I = BB.getFirstInsertionPt(); I != E; ++I) { |
| if (IsInPair.find(I) == IsInPair.end()) continue; |
| |
| DenseSet<Value *> Users; |
| AliasSetTracker WriteSet(*AA); |
| for (BasicBlock::iterator J = llvm::next(I); J != E; ++J) { |
| (void) trackUsesOfI(Users, WriteSet, I, J); |
| |
| if (J == EL) |
| break; |
| } |
| |
| for (DenseSet<Value *>::iterator U = Users.begin(), E = Users.end(); |
| U != E; ++U) { |
| if (IsInPair.find(*U) == IsInPair.end()) continue; |
| PairableInstUsers.insert(ValuePair(I, *U)); |
| } |
| |
| if (I == EL) |
| break; |
| } |
| } |
| |
| // Returns true if an input to pair P is an output of pair Q and also an |
| // input of pair Q is an output of pair P. If this is the case, then these |
| // two pairs cannot be simultaneously fused. |
| bool BBVectorize::pairsConflict(ValuePair P, ValuePair Q, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<ValuePair, std::vector<ValuePair> > *PairableInstUserMap, |
| DenseSet<VPPair> *PairableInstUserPairSet) { |
| // Two pairs are in conflict if they are mutual Users of eachother. |
| bool QUsesP = PairableInstUsers.count(ValuePair(P.first, Q.first)) || |
| PairableInstUsers.count(ValuePair(P.first, Q.second)) || |
| PairableInstUsers.count(ValuePair(P.second, Q.first)) || |
| PairableInstUsers.count(ValuePair(P.second, Q.second)); |
| bool PUsesQ = PairableInstUsers.count(ValuePair(Q.first, P.first)) || |
| PairableInstUsers.count(ValuePair(Q.first, P.second)) || |
| PairableInstUsers.count(ValuePair(Q.second, P.first)) || |
| PairableInstUsers.count(ValuePair(Q.second, P.second)); |
| if (PairableInstUserMap) { |
| // FIXME: The expensive part of the cycle check is not so much the cycle |
| // check itself but this edge insertion procedure. This needs some |
| // profiling and probably a different data structure. |
| if (PUsesQ) { |
| if (PairableInstUserPairSet->insert(VPPair(Q, P)).second) |
| (*PairableInstUserMap)[Q].push_back(P); |
| } |
| if (QUsesP) { |
| if (PairableInstUserPairSet->insert(VPPair(P, Q)).second) |
| (*PairableInstUserMap)[P].push_back(Q); |
| } |
| } |
| |
| return (QUsesP && PUsesQ); |
| } |
| |
| // This function walks the use graph of current pairs to see if, starting |
| // from P, the walk returns to P. |
| bool BBVectorize::pairWillFormCycle(ValuePair P, |
| DenseMap<ValuePair, std::vector<ValuePair> > &PairableInstUserMap, |
| DenseSet<ValuePair> &CurrentPairs) { |
| DEBUG(if (DebugCycleCheck) |
| dbgs() << "BBV: starting cycle check for : " << *P.first << " <-> " |
| << *P.second << "\n"); |
| // A lookup table of visisted pairs is kept because the PairableInstUserMap |
| // contains non-direct associations. |
| DenseSet<ValuePair> Visited; |
| SmallVector<ValuePair, 32> Q; |
| // General depth-first post-order traversal: |
| Q.push_back(P); |
| do { |
| ValuePair QTop = Q.pop_back_val(); |
| Visited.insert(QTop); |
| |
| DEBUG(if (DebugCycleCheck) |
| dbgs() << "BBV: cycle check visiting: " << *QTop.first << " <-> " |
| << *QTop.second << "\n"); |
| DenseMap<ValuePair, std::vector<ValuePair> >::iterator QQ = |
| PairableInstUserMap.find(QTop); |
| if (QQ == PairableInstUserMap.end()) |
| continue; |
| |
| for (std::vector<ValuePair>::iterator C = QQ->second.begin(), |
| CE = QQ->second.end(); C != CE; ++C) { |
| if (*C == P) { |
| DEBUG(dbgs() |
| << "BBV: rejected to prevent non-trivial cycle formation: " |
| << QTop.first << " <-> " << C->second << "\n"); |
| return true; |
| } |
| |
| if (CurrentPairs.count(*C) && !Visited.count(*C)) |
| Q.push_back(*C); |
| } |
| } while (!Q.empty()); |
| |
| return false; |
| } |
| |
| // This function builds the initial dag of connected pairs with the |
| // pair J at the root. |
| void BBVectorize::buildInitialDAGFor( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseMap<ValuePair, size_t> &DAG, ValuePair J) { |
| // Each of these pairs is viewed as the root node of a DAG. The DAG |
| // is then walked (depth-first). As this happens, we keep track of |
| // the pairs that compose the DAG and the maximum depth of the DAG. |
| SmallVector<ValuePairWithDepth, 32> Q; |
| // General depth-first post-order traversal: |
| Q.push_back(ValuePairWithDepth(J, getDepthFactor(J.first))); |
| do { |
| ValuePairWithDepth QTop = Q.back(); |
| |
| // Push each child onto the queue: |
| bool MoreChildren = false; |
| size_t MaxChildDepth = QTop.second; |
| DenseMap<ValuePair, std::vector<ValuePair> >::iterator QQ = |
| ConnectedPairs.find(QTop.first); |
| if (QQ != ConnectedPairs.end()) |
| for (std::vector<ValuePair>::iterator k = QQ->second.begin(), |
| ke = QQ->second.end(); k != ke; ++k) { |
| // Make sure that this child pair is still a candidate: |
| if (CandidatePairsSet.count(*k)) { |
| DenseMap<ValuePair, size_t>::iterator C = DAG.find(*k); |
| if (C == DAG.end()) { |
| size_t d = getDepthFactor(k->first); |
| Q.push_back(ValuePairWithDepth(*k, QTop.second+d)); |
| MoreChildren = true; |
| } else { |
| MaxChildDepth = std::max(MaxChildDepth, C->second); |
| } |
| } |
| } |
| |
| if (!MoreChildren) { |
| // Record the current pair as part of the DAG: |
| DAG.insert(ValuePairWithDepth(QTop.first, MaxChildDepth)); |
| Q.pop_back(); |
| } |
| } while (!Q.empty()); |
| } |
| |
| // Given some initial dag, prune it by removing conflicting pairs (pairs |
| // that cannot be simultaneously chosen for vectorization). |
| void BBVectorize::pruneDAGFor( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<ValuePair, std::vector<ValuePair> > &PairableInstUserMap, |
| DenseSet<VPPair> &PairableInstUserPairSet, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseMap<ValuePair, size_t> &DAG, |
| DenseSet<ValuePair> &PrunedDAG, ValuePair J, |
| bool UseCycleCheck) { |
| SmallVector<ValuePairWithDepth, 32> Q; |
| // General depth-first post-order traversal: |
| Q.push_back(ValuePairWithDepth(J, getDepthFactor(J.first))); |
| do { |
| ValuePairWithDepth QTop = Q.pop_back_val(); |
| PrunedDAG.insert(QTop.first); |
| |
| // Visit each child, pruning as necessary... |
| SmallVector<ValuePairWithDepth, 8> BestChildren; |
| DenseMap<ValuePair, std::vector<ValuePair> >::iterator QQ = |
| ConnectedPairs.find(QTop.first); |
| if (QQ == ConnectedPairs.end()) |
| continue; |
| |
| for (std::vector<ValuePair>::iterator K = QQ->second.begin(), |
| KE = QQ->second.end(); K != KE; ++K) { |
| DenseMap<ValuePair, size_t>::iterator C = DAG.find(*K); |
| if (C == DAG.end()) continue; |
| |
| // This child is in the DAG, now we need to make sure it is the |
| // best of any conflicting children. There could be multiple |
| // conflicting children, so first, determine if we're keeping |
| // this child, then delete conflicting children as necessary. |
| |
| // It is also necessary to guard against pairing-induced |
| // dependencies. Consider instructions a .. x .. y .. b |
| // such that (a,b) are to be fused and (x,y) are to be fused |
| // but a is an input to x and b is an output from y. This |
| // means that y cannot be moved after b but x must be moved |
| // after b for (a,b) to be fused. In other words, after |
| // fusing (a,b) we have y .. a/b .. x where y is an input |
| // to a/b and x is an output to a/b: x and y can no longer |
| // be legally fused. To prevent this condition, we must |
| // make sure that a child pair added to the DAG is not |
| // both an input and output of an already-selected pair. |
| |
| // Pairing-induced dependencies can also form from more complicated |
| // cycles. The pair vs. pair conflicts are easy to check, and so |
| // that is done explicitly for "fast rejection", and because for |
| // child vs. child conflicts, we may prefer to keep the current |
| // pair in preference to the already-selected child. |
| DenseSet<ValuePair> CurrentPairs; |
| |
| bool CanAdd = true; |
| for (SmallVector<ValuePairWithDepth, 8>::iterator C2 |
| = BestChildren.begin(), E2 = BestChildren.end(); |
| C2 != E2; ++C2) { |
| if (C2->first.first == C->first.first || |
| C2->first.first == C->first.second || |
| C2->first.second == C->first.first || |
| C2->first.second == C->first.second || |
| pairsConflict(C2->first, C->first, PairableInstUsers, |
| UseCycleCheck ? &PairableInstUserMap : 0, |
| UseCycleCheck ? &PairableInstUserPairSet : 0)) { |
| if (C2->second >= C->second) { |
| CanAdd = false; |
| break; |
| } |
| |
| CurrentPairs.insert(C2->first); |
| } |
| } |
| if (!CanAdd) continue; |
| |
| // Even worse, this child could conflict with another node already |
| // selected for the DAG. If that is the case, ignore this child. |
| for (DenseSet<ValuePair>::iterator T = PrunedDAG.begin(), |
| E2 = PrunedDAG.end(); T != E2; ++T) { |
| if (T->first == C->first.first || |
| T->first == C->first.second || |
| T->second == C->first.first || |
| T->second == C->first.second || |
| pairsConflict(*T, C->first, PairableInstUsers, |
| UseCycleCheck ? &PairableInstUserMap : 0, |
| UseCycleCheck ? &PairableInstUserPairSet : 0)) { |
| CanAdd = false; |
| break; |
| } |
| |
| CurrentPairs.insert(*T); |
| } |
| if (!CanAdd) continue; |
| |
| // And check the queue too... |
| for (SmallVector<ValuePairWithDepth, 32>::iterator C2 = Q.begin(), |
| E2 = Q.end(); C2 != E2; ++C2) { |
| if (C2->first.first == C->first.first || |
| C2->first.first == C->first.second || |
| C2->first.second == C->first.first || |
| C2->first.second == C->first.second || |
| pairsConflict(C2->first, C->first, PairableInstUsers, |
| UseCycleCheck ? &PairableInstUserMap : 0, |
| UseCycleCheck ? &PairableInstUserPairSet : 0)) { |
| CanAdd = false; |
| break; |
| } |
| |
| CurrentPairs.insert(C2->first); |
| } |
| if (!CanAdd) continue; |
| |
| // Last but not least, check for a conflict with any of the |
| // already-chosen pairs. |
| for (DenseMap<Value *, Value *>::iterator C2 = |
| ChosenPairs.begin(), E2 = ChosenPairs.end(); |
| C2 != E2; ++C2) { |
| if (pairsConflict(*C2, C->first, PairableInstUsers, |
| UseCycleCheck ? &PairableInstUserMap : 0, |
| UseCycleCheck ? &PairableInstUserPairSet : 0)) { |
| CanAdd = false; |
| break; |
| } |
| |
| CurrentPairs.insert(*C2); |
| } |
| if (!CanAdd) continue; |
| |
| // To check for non-trivial cycles formed by the addition of the |
| // current pair we've formed a list of all relevant pairs, now use a |
| // graph walk to check for a cycle. We start from the current pair and |
| // walk the use dag to see if we again reach the current pair. If we |
| // do, then the current pair is rejected. |
| |
| // FIXME: It may be more efficient to use a topological-ordering |
| // algorithm to improve the cycle check. This should be investigated. |
| if (UseCycleCheck && |
| pairWillFormCycle(C->first, PairableInstUserMap, CurrentPairs)) |
| continue; |
| |
| // This child can be added, but we may have chosen it in preference |
| // to an already-selected child. Check for this here, and if a |
| // conflict is found, then remove the previously-selected child |
| // before adding this one in its place. |
| for (SmallVector<ValuePairWithDepth, 8>::iterator C2 |
| = BestChildren.begin(); C2 != BestChildren.end();) { |
| if (C2->first.first == C->first.first || |
| C2->first.first == C->first.second || |
| C2->first.second == C->first.first || |
| C2->first.second == C->first.second || |
| pairsConflict(C2->first, C->first, PairableInstUsers)) |
| C2 = BestChildren.erase(C2); |
| else |
| ++C2; |
| } |
| |
| BestChildren.push_back(ValuePairWithDepth(C->first, C->second)); |
| } |
| |
| for (SmallVector<ValuePairWithDepth, 8>::iterator C |
| = BestChildren.begin(), E2 = BestChildren.end(); |
| C != E2; ++C) { |
| size_t DepthF = getDepthFactor(C->first.first); |
| Q.push_back(ValuePairWithDepth(C->first, QTop.second+DepthF)); |
| } |
| } while (!Q.empty()); |
| } |
| |
| // This function finds the best dag of mututally-compatible connected |
| // pairs, given the choice of root pairs as an iterator range. |
| void BBVectorize::findBestDAGFor( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| DenseMap<ValuePair, int> &CandidatePairCostSavings, |
| std::vector<Value *> &PairableInsts, |
| DenseSet<ValuePair> &FixedOrderPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairDeps, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<ValuePair, std::vector<ValuePair> > &PairableInstUserMap, |
| DenseSet<VPPair> &PairableInstUserPairSet, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseSet<ValuePair> &BestDAG, size_t &BestMaxDepth, |
| int &BestEffSize, Value *II, std::vector<Value *>&JJ, |
| bool UseCycleCheck) { |
| for (std::vector<Value *>::iterator J = JJ.begin(), JE = JJ.end(); |
| J != JE; ++J) { |
| ValuePair IJ(II, *J); |
| if (!CandidatePairsSet.count(IJ)) |
| continue; |
| |
| // Before going any further, make sure that this pair does not |
| // conflict with any already-selected pairs (see comment below |
| // near the DAG pruning for more details). |
| DenseSet<ValuePair> ChosenPairSet; |
| bool DoesConflict = false; |
| for (DenseMap<Value *, Value *>::iterator C = ChosenPairs.begin(), |
| E = ChosenPairs.end(); C != E; ++C) { |
| if (pairsConflict(*C, IJ, PairableInstUsers, |
| UseCycleCheck ? &PairableInstUserMap : 0, |
| UseCycleCheck ? &PairableInstUserPairSet : 0)) { |
| DoesConflict = true; |
| break; |
| } |
| |
| ChosenPairSet.insert(*C); |
| } |
| if (DoesConflict) continue; |
| |
| if (UseCycleCheck && |
| pairWillFormCycle(IJ, PairableInstUserMap, ChosenPairSet)) |
| continue; |
| |
| DenseMap<ValuePair, size_t> DAG; |
| buildInitialDAGFor(CandidatePairs, CandidatePairsSet, |
| PairableInsts, ConnectedPairs, |
| PairableInstUsers, ChosenPairs, DAG, IJ); |
| |
| // Because we'll keep the child with the largest depth, the largest |
| // depth is still the same in the unpruned DAG. |
| size_t MaxDepth = DAG.lookup(IJ); |
| |
| DEBUG(if (DebugPairSelection) dbgs() << "BBV: found DAG for pair {" |
| << *IJ.first << " <-> " << *IJ.second << "} of depth " << |
| MaxDepth << " and size " << DAG.size() << "\n"); |
| |
| // At this point the DAG has been constructed, but, may contain |
| // contradictory children (meaning that different children of |
| // some dag node may be attempting to fuse the same instruction). |
| // So now we walk the dag again, in the case of a conflict, |
| // keep only the child with the largest depth. To break a tie, |
| // favor the first child. |
| |
| DenseSet<ValuePair> PrunedDAG; |
| pruneDAGFor(CandidatePairs, PairableInsts, ConnectedPairs, |
| PairableInstUsers, PairableInstUserMap, |
| PairableInstUserPairSet, |
| ChosenPairs, DAG, PrunedDAG, IJ, UseCycleCheck); |
| |
| int EffSize = 0; |
| if (TTI) { |
| DenseSet<Value *> PrunedDAGInstrs; |
| for (DenseSet<ValuePair>::iterator S = PrunedDAG.begin(), |
| E = PrunedDAG.end(); S != E; ++S) { |
| PrunedDAGInstrs.insert(S->first); |
| PrunedDAGInstrs.insert(S->second); |
| } |
| |
| // The set of pairs that have already contributed to the total cost. |
| DenseSet<ValuePair> IncomingPairs; |
| |
| // If the cost model were perfect, this might not be necessary; but we |
| // need to make sure that we don't get stuck vectorizing our own |
| // shuffle chains. |
| bool HasNontrivialInsts = false; |
| |
| // The node weights represent the cost savings associated with |
| // fusing the pair of instructions. |
| for (DenseSet<ValuePair>::iterator S = PrunedDAG.begin(), |
| E = PrunedDAG.end(); S != E; ++S) { |
| if (!isa<ShuffleVectorInst>(S->first) && |
| !isa<InsertElementInst>(S->first) && |
| !isa<ExtractElementInst>(S->first)) |
| HasNontrivialInsts = true; |
| |
| bool FlipOrder = false; |
| |
| if (getDepthFactor(S->first)) { |
| int ESContrib = CandidatePairCostSavings.find(*S)->second; |
| DEBUG(if (DebugPairSelection) dbgs() << "\tweight {" |
| << *S->first << " <-> " << *S->second << "} = " << |
| ESContrib << "\n"); |
| EffSize += ESContrib; |
| } |
| |
| // The edge weights contribute in a negative sense: they represent |
| // the cost of shuffles. |
| DenseMap<ValuePair, std::vector<ValuePair> >::iterator SS = |
| ConnectedPairDeps.find(*S); |
| if (SS != ConnectedPairDeps.end()) { |
| unsigned NumDepsDirect = 0, NumDepsSwap = 0; |
| for (std::vector<ValuePair>::iterator T = SS->second.begin(), |
| TE = SS->second.end(); T != TE; ++T) { |
| VPPair Q(*S, *T); |
| if (!PrunedDAG.count(Q.second)) |
| continue; |
| DenseMap<VPPair, unsigned>::iterator R = |
| PairConnectionTypes.find(VPPair(Q.second, Q.first)); |
| assert(R != PairConnectionTypes.end() && |
| "Cannot find pair connection type"); |
| if (R->second == PairConnectionDirect) |
| ++NumDepsDirect; |
| else if (R->second == PairConnectionSwap) |
| ++NumDepsSwap; |
| } |
| |
| // If there are more swaps than direct connections, then |
| // the pair order will be flipped during fusion. So the real |
| // number of swaps is the minimum number. |
| FlipOrder = !FixedOrderPairs.count(*S) && |
| ((NumDepsSwap > NumDepsDirect) || |
| FixedOrderPairs.count(ValuePair(S->second, S->first))); |
| |
| for (std::vector<ValuePair>::iterator T = SS->second.begin(), |
| TE = SS->second.end(); T != TE; ++T) { |
| VPPair Q(*S, *T); |
| if (!PrunedDAG.count(Q.second)) |
| continue; |
| DenseMap<VPPair, unsigned>::iterator R = |
| PairConnectionTypes.find(VPPair(Q.second, Q.first)); |
| assert(R != PairConnectionTypes.end() && |
| "Cannot find pair connection type"); |
| Type *Ty1 = Q.second.first->getType(), |
| *Ty2 = Q.second.second->getType(); |
| Type *VTy = getVecTypeForPair(Ty1, Ty2); |
| if ((R->second == PairConnectionDirect && FlipOrder) || |
| (R->second == PairConnectionSwap && !FlipOrder) || |
| R->second == PairConnectionSplat) { |
| int ESContrib = (int) getInstrCost(Instruction::ShuffleVector, |
| VTy, VTy); |
| |
| if (VTy->getVectorNumElements() == 2) { |
| if (R->second == PairConnectionSplat) |
| ESContrib = std::min(ESContrib, (int) TTI->getShuffleCost( |
| TargetTransformInfo::SK_Broadcast, VTy)); |
| else |
| ESContrib = std::min(ESContrib, (int) TTI->getShuffleCost( |
| TargetTransformInfo::SK_Reverse, VTy)); |
| } |
| |
| DEBUG(if (DebugPairSelection) dbgs() << "\tcost {" << |
| *Q.second.first << " <-> " << *Q.second.second << |
| "} -> {" << |
| *S->first << " <-> " << *S->second << "} = " << |
| ESContrib << "\n"); |
| EffSize -= ESContrib; |
| } |
| } |
| } |
| |
| // Compute the cost of outgoing edges. We assume that edges outgoing |
| // to shuffles, inserts or extracts can be merged, and so contribute |
| // no additional cost. |
| if (!S->first->getType()->isVoidTy()) { |
| Type *Ty1 = S->first->getType(), |
| *Ty2 = S->second->getType(); |
| Type *VTy = getVecTypeForPair(Ty1, Ty2); |
| |
| bool NeedsExtraction = false; |
| for (Value::use_iterator I = S->first->use_begin(), |
| IE = S->first->use_end(); I != IE; ++I) { |
| if (ShuffleVectorInst *SI = dyn_cast<ShuffleVectorInst>(*I)) { |
| // Shuffle can be folded if it has no other input |
| if (isa<UndefValue>(SI->getOperand(1))) |
| continue; |
| } |
| if (isa<ExtractElementInst>(*I)) |
| continue; |
| if (PrunedDAGInstrs.count(*I)) |
| continue; |
| NeedsExtraction = true; |
| break; |
| } |
| |
| if (NeedsExtraction) { |
| int ESContrib; |
| if (Ty1->isVectorTy()) { |
| ESContrib = (int) getInstrCost(Instruction::ShuffleVector, |
| Ty1, VTy); |
| ESContrib = std::min(ESContrib, (int) TTI->getShuffleCost( |
| TargetTransformInfo::SK_ExtractSubvector, VTy, 0, Ty1)); |
| } else |
| ESContrib = (int) TTI->getVectorInstrCost( |
| Instruction::ExtractElement, VTy, 0); |
| |
| DEBUG(if (DebugPairSelection) dbgs() << "\tcost {" << |
| *S->first << "} = " << ESContrib << "\n"); |
| EffSize -= ESContrib; |
| } |
| |
| NeedsExtraction = false; |
| for (Value::use_iterator I = S->second->use_begin(), |
| IE = S->second->use_end(); I != IE; ++I) { |
| if (ShuffleVectorInst *SI = dyn_cast<ShuffleVectorInst>(*I)) { |
| // Shuffle can be folded if it has no other input |
| if (isa<UndefValue>(SI->getOperand(1))) |
| continue; |
| } |
| if (isa<ExtractElementInst>(*I)) |
| continue; |
| if (PrunedDAGInstrs.count(*I)) |
| continue; |
| NeedsExtraction = true; |
| break; |
| } |
| |
| if (NeedsExtraction) { |
| int ESContrib; |
| if (Ty2->isVectorTy()) { |
| ESContrib = (int) getInstrCost(Instruction::ShuffleVector, |
| Ty2, VTy); |
| ESContrib = std::min(ESContrib, (int) TTI->getShuffleCost( |
| TargetTransformInfo::SK_ExtractSubvector, VTy, |
| Ty1->isVectorTy() ? Ty1->getVectorNumElements() : 1, Ty2)); |
| } else |
| ESContrib = (int) TTI->getVectorInstrCost( |
| Instruction::ExtractElement, VTy, 1); |
| DEBUG(if (DebugPairSelection) dbgs() << "\tcost {" << |
| *S->second << "} = " << ESContrib << "\n"); |
| EffSize -= ESContrib; |
| } |
| } |
| |
| // Compute the cost of incoming edges. |
| if (!isa<LoadInst>(S->first) && !isa<StoreInst>(S->first)) { |
| Instruction *S1 = cast<Instruction>(S->first), |
| *S2 = cast<Instruction>(S->second); |
| for (unsigned o = 0; o < S1->getNumOperands(); ++o) { |
| Value *O1 = S1->getOperand(o), *O2 = S2->getOperand(o); |
| |
| // Combining constants into vector constants (or small vector |
| // constants into larger ones are assumed free). |
| if (isa<Constant>(O1) && isa<Constant>(O2)) |
| continue; |
| |
| if (FlipOrder) |
| std::swap(O1, O2); |
| |
| ValuePair VP = ValuePair(O1, O2); |
| ValuePair VPR = ValuePair(O2, O1); |
| |
| // Internal edges are not handled here. |
| if (PrunedDAG.count(VP) || PrunedDAG.count(VPR)) |
| continue; |
| |
| Type *Ty1 = O1->getType(), |
| *Ty2 = O2->getType(); |
| Type *VTy = getVecTypeForPair(Ty1, Ty2); |
| |
| // Combining vector operations of the same type is also assumed |
| // folded with other operations. |
| if (Ty1 == Ty2) { |
| // If both are insert elements, then both can be widened. |
| InsertElementInst *IEO1 = dyn_cast<InsertElementInst>(O1), |
| *IEO2 = dyn_cast<InsertElementInst>(O2); |
| if (IEO1 && IEO2 && isPureIEChain(IEO1) && isPureIEChain(IEO2)) |
| continue; |
| // If both are extract elements, and both have the same input |
| // type, then they can be replaced with a shuffle |
| ExtractElementInst *EIO1 = dyn_cast<ExtractElementInst>(O1), |
| *EIO2 = dyn_cast<ExtractElementInst>(O2); |
| if (EIO1 && EIO2 && |
| EIO1->getOperand(0)->getType() == |
| EIO2->getOperand(0)->getType()) |
| continue; |
| // If both are a shuffle with equal operand types and only two |
| // unqiue operands, then they can be replaced with a single |
| // shuffle |
| ShuffleVectorInst *SIO1 = dyn_cast<ShuffleVectorInst>(O1), |
| *SIO2 = dyn_cast<ShuffleVectorInst>(O2); |
| if (SIO1 && SIO2 && |
| SIO1->getOperand(0)->getType() == |
| SIO2->getOperand(0)->getType()) { |
| SmallSet<Value *, 4> SIOps; |
| SIOps.insert(SIO1->getOperand(0)); |
| SIOps.insert(SIO1->getOperand(1)); |
| SIOps.insert(SIO2->getOperand(0)); |
| SIOps.insert(SIO2->getOperand(1)); |
| if (SIOps.size() <= 2) |
| continue; |
| } |
| } |
| |
| int ESContrib; |
| // This pair has already been formed. |
| if (IncomingPairs.count(VP)) { |
| continue; |
| } else if (IncomingPairs.count(VPR)) { |
| ESContrib = (int) getInstrCost(Instruction::ShuffleVector, |
| VTy, VTy); |
| |
| if (VTy->getVectorNumElements() == 2) |
| ESContrib = std::min(ESContrib, (int) TTI->getShuffleCost( |
| TargetTransformInfo::SK_Reverse, VTy)); |
| } else if (!Ty1->isVectorTy() && !Ty2->isVectorTy()) { |
| ESContrib = (int) TTI->getVectorInstrCost( |
| Instruction::InsertElement, VTy, 0); |
| ESContrib += (int) TTI->getVectorInstrCost( |
| Instruction::InsertElement, VTy, 1); |
| } else if (!Ty1->isVectorTy()) { |
| // O1 needs to be inserted into a vector of size O2, and then |
| // both need to be shuffled together. |
| ESContrib = (int) TTI->getVectorInstrCost( |
| Instruction::InsertElement, Ty2, 0); |
| ESContrib += (int) getInstrCost(Instruction::ShuffleVector, |
| VTy, Ty2); |
| } else if (!Ty2->isVectorTy()) { |
| // O2 needs to be inserted into a vector of size O1, and then |
| // both need to be shuffled together. |
| ESContrib = (int) TTI->getVectorInstrCost( |
| Instruction::InsertElement, Ty1, 0); |
| ESContrib += (int) getInstrCost(Instruction::ShuffleVector, |
| VTy, Ty1); |
| } else { |
| Type *TyBig = Ty1, *TySmall = Ty2; |
| if (Ty2->getVectorNumElements() > Ty1->getVectorNumElements()) |
| std::swap(TyBig, TySmall); |
| |
| ESContrib = (int) getInstrCost(Instruction::ShuffleVector, |
| VTy, TyBig); |
| if (TyBig != TySmall) |
| ESContrib += (int) getInstrCost(Instruction::ShuffleVector, |
| TyBig, TySmall); |
| } |
| |
| DEBUG(if (DebugPairSelection) dbgs() << "\tcost {" |
| << *O1 << " <-> " << *O2 << "} = " << |
| ESContrib << "\n"); |
| EffSize -= ESContrib; |
| IncomingPairs.insert(VP); |
| } |
| } |
| } |
| |
| if (!HasNontrivialInsts) { |
| DEBUG(if (DebugPairSelection) dbgs() << |
| "\tNo non-trivial instructions in DAG;" |
| " override to zero effective size\n"); |
| EffSize = 0; |
| } |
| } else { |
| for (DenseSet<ValuePair>::iterator S = PrunedDAG.begin(), |
| E = PrunedDAG.end(); S != E; ++S) |
| EffSize += (int) getDepthFactor(S->first); |
| } |
| |
| DEBUG(if (DebugPairSelection) |
| dbgs() << "BBV: found pruned DAG for pair {" |
| << *IJ.first << " <-> " << *IJ.second << "} of depth " << |
| MaxDepth << " and size " << PrunedDAG.size() << |
| " (effective size: " << EffSize << ")\n"); |
| if (((TTI && !UseChainDepthWithTI) || |
| MaxDepth >= Config.ReqChainDepth) && |
| EffSize > 0 && EffSize > BestEffSize) { |
| BestMaxDepth = MaxDepth; |
| BestEffSize = EffSize; |
| BestDAG = PrunedDAG; |
| } |
| } |
| } |
| |
| // Given the list of candidate pairs, this function selects those |
| // that will be fused into vector instructions. |
| void BBVectorize::choosePairs( |
| DenseMap<Value *, std::vector<Value *> > &CandidatePairs, |
| DenseSet<ValuePair> &CandidatePairsSet, |
| DenseMap<ValuePair, int> &CandidatePairCostSavings, |
| std::vector<Value *> &PairableInsts, |
| DenseSet<ValuePair> &FixedOrderPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairDeps, |
| DenseSet<ValuePair> &PairableInstUsers, |
| DenseMap<Value *, Value *>& ChosenPairs) { |
| bool UseCycleCheck = |
| CandidatePairsSet.size() <= Config.MaxCandPairsForCycleCheck; |
| |
| DenseMap<Value *, std::vector<Value *> > CandidatePairs2; |
| for (DenseSet<ValuePair>::iterator I = CandidatePairsSet.begin(), |
| E = CandidatePairsSet.end(); I != E; ++I) { |
| std::vector<Value *> &JJ = CandidatePairs2[I->second]; |
| if (JJ.empty()) JJ.reserve(32); |
| JJ.push_back(I->first); |
| } |
| |
| DenseMap<ValuePair, std::vector<ValuePair> > PairableInstUserMap; |
| DenseSet<VPPair> PairableInstUserPairSet; |
| for (std::vector<Value *>::iterator I = PairableInsts.begin(), |
| E = PairableInsts.end(); I != E; ++I) { |
| // The number of possible pairings for this variable: |
| size_t NumChoices = CandidatePairs.lookup(*I).size(); |
| if (!NumChoices) continue; |
| |
| std::vector<Value *> &JJ = CandidatePairs[*I]; |
| |
| // The best pair to choose and its dag: |
| size_t BestMaxDepth = 0; |
| int BestEffSize = 0; |
| DenseSet<ValuePair> BestDAG; |
| findBestDAGFor(CandidatePairs, CandidatePairsSet, |
| CandidatePairCostSavings, |
| PairableInsts, FixedOrderPairs, PairConnectionTypes, |
| ConnectedPairs, ConnectedPairDeps, |
| PairableInstUsers, PairableInstUserMap, |
| PairableInstUserPairSet, ChosenPairs, |
| BestDAG, BestMaxDepth, BestEffSize, *I, JJ, |
| UseCycleCheck); |
| |
| if (BestDAG.empty()) |
| continue; |
| |
| // A dag has been chosen (or not) at this point. If no dag was |
| // chosen, then this instruction, I, cannot be paired (and is no longer |
| // considered). |
| |
| DEBUG(dbgs() << "BBV: selected pairs in the best DAG for: " |
| << *cast<Instruction>(*I) << "\n"); |
| |
| for (DenseSet<ValuePair>::iterator S = BestDAG.begin(), |
| SE2 = BestDAG.end(); S != SE2; ++S) { |
| // Insert the members of this dag into the list of chosen pairs. |
| ChosenPairs.insert(ValuePair(S->first, S->second)); |
| DEBUG(dbgs() << "BBV: selected pair: " << *S->first << " <-> " << |
| *S->second << "\n"); |
| |
| // Remove all candidate pairs that have values in the chosen dag. |
| std::vector<Value *> &KK = CandidatePairs[S->first]; |
| for (std::vector<Value *>::iterator K = KK.begin(), KE = KK.end(); |
| K != KE; ++K) { |
| if (*K == S->second) |
| continue; |
| |
| CandidatePairsSet.erase(ValuePair(S->first, *K)); |
| } |
| |
| std::vector<Value *> &LL = CandidatePairs2[S->second]; |
| for (std::vector<Value *>::iterator L = LL.begin(), LE = LL.end(); |
| L != LE; ++L) { |
| if (*L == S->first) |
| continue; |
| |
| CandidatePairsSet.erase(ValuePair(*L, S->second)); |
| } |
| |
| std::vector<Value *> &MM = CandidatePairs[S->second]; |
| for (std::vector<Value *>::iterator M = MM.begin(), ME = MM.end(); |
| M != ME; ++M) { |
| assert(*M != S->first && "Flipped pair in candidate list?"); |
| CandidatePairsSet.erase(ValuePair(S->second, *M)); |
| } |
| |
| std::vector<Value *> &NN = CandidatePairs2[S->first]; |
| for (std::vector<Value *>::iterator N = NN.begin(), NE = NN.end(); |
| N != NE; ++N) { |
| assert(*N != S->second && "Flipped pair in candidate list?"); |
| CandidatePairsSet.erase(ValuePair(*N, S->first)); |
| } |
| } |
| } |
| |
| DEBUG(dbgs() << "BBV: selected " << ChosenPairs.size() << " pairs.\n"); |
| } |
| |
| std::string getReplacementName(Instruction *I, bool IsInput, unsigned o, |
| unsigned n = 0) { |
| if (!I->hasName()) |
| return ""; |
| |
| return (I->getName() + (IsInput ? ".v.i" : ".v.r") + utostr(o) + |
| (n > 0 ? "." + utostr(n) : "")).str(); |
| } |
| |
| // Returns the value that is to be used as the pointer input to the vector |
| // instruction that fuses I with J. |
| Value *BBVectorize::getReplacementPointerInput(LLVMContext& Context, |
| Instruction *I, Instruction *J, unsigned o) { |
| Value *IPtr, *JPtr; |
| unsigned IAlignment, JAlignment, IAddressSpace, JAddressSpace; |
| int64_t OffsetInElmts; |
| |
| // Note: the analysis might fail here, that is why the pair order has |
| // been precomputed (OffsetInElmts must be unused here). |
| (void) getPairPtrInfo(I, J, IPtr, JPtr, IAlignment, JAlignment, |
| IAddressSpace, JAddressSpace, |
| OffsetInElmts, false); |
| |
| // The pointer value is taken to be the one with the lowest offset. |
| Value *VPtr = IPtr; |
| |
| Type *ArgTypeI = cast<PointerType>(IPtr->getType())->getElementType(); |
| Type *ArgTypeJ = cast<PointerType>(JPtr->getType())->getElementType(); |
| Type *VArgType = getVecTypeForPair(ArgTypeI, ArgTypeJ); |
| Type *VArgPtrType = PointerType::get(VArgType, |
| cast<PointerType>(IPtr->getType())->getAddressSpace()); |
| return new BitCastInst(VPtr, VArgPtrType, getReplacementName(I, true, o), |
| /* insert before */ I); |
| } |
| |
| void BBVectorize::fillNewShuffleMask(LLVMContext& Context, Instruction *J, |
| unsigned MaskOffset, unsigned NumInElem, |
| unsigned NumInElem1, unsigned IdxOffset, |
| std::vector<Constant*> &Mask) { |
| unsigned NumElem1 = cast<VectorType>(J->getType())->getNumElements(); |
| for (unsigned v = 0; v < NumElem1; ++v) { |
| int m = cast<ShuffleVectorInst>(J)->getMaskValue(v); |
| if (m < 0) { |
| Mask[v+MaskOffset] = UndefValue::get(Type::getInt32Ty(Context)); |
| } else { |
| unsigned mm = m + (int) IdxOffset; |
| if (m >= (int) NumInElem1) |
| mm += (int) NumInElem; |
| |
| Mask[v+MaskOffset] = |
| ConstantInt::get(Type::getInt32Ty(Context), mm); |
| } |
| } |
| } |
| |
| // Returns the value that is to be used as the vector-shuffle mask to the |
| // vector instruction that fuses I with J. |
| Value *BBVectorize::getReplacementShuffleMask(LLVMContext& Context, |
| Instruction *I, Instruction *J) { |
| // This is the shuffle mask. We need to append the second |
| // mask to the first, and the numbers need to be adjusted. |
| |
| Type *ArgTypeI = I->getType(); |
| Type *ArgTypeJ = J->getType(); |
| Type *VArgType = getVecTypeForPair(ArgTypeI, ArgTypeJ); |
| |
| unsigned NumElemI = cast<VectorType>(ArgTypeI)->getNumElements(); |
| |
| // Get the total number of elements in the fused vector type. |
| // By definition, this must equal the number of elements in |
| // the final mask. |
| unsigned NumElem = cast<VectorType>(VArgType)->getNumElements(); |
| std::vector<Constant*> Mask(NumElem); |
| |
| Type *OpTypeI = I->getOperand(0)->getType(); |
| unsigned NumInElemI = cast<VectorType>(OpTypeI)->getNumElements(); |
| Type *OpTypeJ = J->getOperand(0)->getType(); |
| unsigned NumInElemJ = cast<VectorType>(OpTypeJ)->getNumElements(); |
| |
| // The fused vector will be: |
| // ----------------------------------------------------- |
| // | NumInElemI | NumInElemJ | NumInElemI | NumInElemJ | |
| // ----------------------------------------------------- |
| // from which we'll extract NumElem total elements (where the first NumElemI |
| // of them come from the mask in I and the remainder come from the mask |
| // in J. |
| |
| // For the mask from the first pair... |
| fillNewShuffleMask(Context, I, 0, NumInElemJ, NumInElemI, |
| 0, Mask); |
| |
| // For the mask from the second pair... |
| fillNewShuffleMask(Context, J, NumElemI, NumInElemI, NumInElemJ, |
| NumInElemI, Mask); |
| |
| return ConstantVector::get(Mask); |
| } |
| |
| bool BBVectorize::expandIEChain(LLVMContext& Context, Instruction *I, |
| Instruction *J, unsigned o, Value *&LOp, |
| unsigned numElemL, |
| Type *ArgTypeL, Type *ArgTypeH, |
| bool IBeforeJ, unsigned IdxOff) { |
| bool ExpandedIEChain = false; |
| if (InsertElementInst *LIE = dyn_cast<InsertElementInst>(LOp)) { |
| // If we have a pure insertelement chain, then this can be rewritten |
| // into a chain that directly builds the larger type. |
| if (isPureIEChain(LIE)) { |
| SmallVector<Value *, 8> VectElemts(numElemL, |
| UndefValue::get(ArgTypeL->getScalarType())); |
| InsertElementInst *LIENext = LIE; |
| do { |
| unsigned Idx = |
| cast<ConstantInt>(LIENext->getOperand(2))->getSExtValue(); |
| VectElemts[Idx] = LIENext->getOperand(1); |
| } while ((LIENext = |
| dyn_cast<InsertElementInst>(LIENext->getOperand(0)))); |
| |
| LIENext = 0; |
| Value *LIEPrev = UndefValue::get(ArgTypeH); |
| for (unsigned i = 0; i < numElemL; ++i) { |
| if (isa<UndefValue>(VectElemts[i])) continue; |
| LIENext = InsertElementInst::Create(LIEPrev, VectElemts[i], |
| ConstantInt::get(Type::getInt32Ty(Context), |
| i + IdxOff), |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, i+1)); |
| LIENext->insertBefore(IBeforeJ ? J : I); |
| LIEPrev = LIENext; |
| } |
| |
| LOp = LIENext ? (Value*) LIENext : UndefValue::get(ArgTypeH); |
| ExpandedIEChain = true; |
| } |
| } |
| |
| return ExpandedIEChain; |
| } |
| |
| // Returns the value to be used as the specified operand of the vector |
| // instruction that fuses I with J. |
| Value *BBVectorize::getReplacementInput(LLVMContext& Context, Instruction *I, |
| Instruction *J, unsigned o, bool IBeforeJ) { |
| Value *CV0 = ConstantInt::get(Type::getInt32Ty(Context), 0); |
| Value *CV1 = ConstantInt::get(Type::getInt32Ty(Context), 1); |
| |
| // Compute the fused vector type for this operand |
| Type *ArgTypeI = I->getOperand(o)->getType(); |
| Type *ArgTypeJ = J->getOperand(o)->getType(); |
| VectorType *VArgType = getVecTypeForPair(ArgTypeI, ArgTypeJ); |
| |
| Instruction *L = I, *H = J; |
| Type *ArgTypeL = ArgTypeI, *ArgTypeH = ArgTypeJ; |
| |
| unsigned numElemL; |
| if (ArgTypeL->isVectorTy()) |
| numElemL = cast<VectorType>(ArgTypeL)->getNumElements(); |
| else |
| numElemL = 1; |
| |
| unsigned numElemH; |
| if (ArgTypeH->isVectorTy()) |
| numElemH = cast<VectorType>(ArgTypeH)->getNumElements(); |
| else |
| numElemH = 1; |
| |
| Value *LOp = L->getOperand(o); |
| Value *HOp = H->getOperand(o); |
| unsigned numElem = VArgType->getNumElements(); |
| |
| // First, we check if we can reuse the "original" vector outputs (if these |
| // exist). We might need a shuffle. |
| ExtractElementInst *LEE = dyn_cast<ExtractElementInst>(LOp); |
| ExtractElementInst *HEE = dyn_cast<ExtractElementInst>(HOp); |
| ShuffleVectorInst *LSV = dyn_cast<ShuffleVectorInst>(LOp); |
| ShuffleVectorInst *HSV = dyn_cast<ShuffleVectorInst>(HOp); |
| |
| // FIXME: If we're fusing shuffle instructions, then we can't apply this |
| // optimization. The input vectors to the shuffle might be a different |
| // length from the shuffle outputs. Unfortunately, the replacement |
| // shuffle mask has already been formed, and the mask entries are sensitive |
| // to the sizes of the inputs. |
| bool IsSizeChangeShuffle = |
| isa<ShuffleVectorInst>(L) && |
| (LOp->getType() != L->getType() || HOp->getType() != H->getType()); |
| |
| if ((LEE || LSV) && (HEE || HSV) && !IsSizeChangeShuffle) { |
| // We can have at most two unique vector inputs. |
| bool CanUseInputs = true; |
| Value *I1, *I2 = 0; |
| if (LEE) { |
| I1 = LEE->getOperand(0); |
| } else { |
| I1 = LSV->getOperand(0); |
| I2 = LSV->getOperand(1); |
| if (I2 == I1 || isa<UndefValue>(I2)) |
| I2 = 0; |
| } |
| |
| if (HEE) { |
| Value *I3 = HEE->getOperand(0); |
| if (!I2 && I3 != I1) |
| I2 = I3; |
| else if (I3 != I1 && I3 != I2) |
| CanUseInputs = false; |
| } else { |
| Value *I3 = HSV->getOperand(0); |
| if (!I2 && I3 != I1) |
| I2 = I3; |
| else if (I3 != I1 && I3 != I2) |
| CanUseInputs = false; |
| |
| if (CanUseInputs) { |
| Value *I4 = HSV->getOperand(1); |
| if (!isa<UndefValue>(I4)) { |
| if (!I2 && I4 != I1) |
| I2 = I4; |
| else if (I4 != I1 && I4 != I2) |
| CanUseInputs = false; |
| } |
| } |
| } |
| |
| if (CanUseInputs) { |
| unsigned LOpElem = |
| cast<VectorType>(cast<Instruction>(LOp)->getOperand(0)->getType()) |
| ->getNumElements(); |
| unsigned HOpElem = |
| cast<VectorType>(cast<Instruction>(HOp)->getOperand(0)->getType()) |
| ->getNumElements(); |
| |
| // We have one or two input vectors. We need to map each index of the |
| // operands to the index of the original vector. |
| SmallVector<std::pair<int, int>, 8> II(numElem); |
| for (unsigned i = 0; i < numElemL; ++i) { |
| int Idx, INum; |
| if (LEE) { |
| Idx = |
| cast<ConstantInt>(LEE->getOperand(1))->getSExtValue(); |
| INum = LEE->getOperand(0) == I1 ? 0 : 1; |
| } else { |
| Idx = LSV->getMaskValue(i); |
| if (Idx < (int) LOpElem) { |
| INum = LSV->getOperand(0) == I1 ? 0 : 1; |
| } else { |
| Idx -= LOpElem; |
| INum = LSV->getOperand(1) == I1 ? 0 : 1; |
| } |
| } |
| |
| II[i] = std::pair<int, int>(Idx, INum); |
| } |
| for (unsigned i = 0; i < numElemH; ++i) { |
| int Idx, INum; |
| if (HEE) { |
| Idx = |
| cast<ConstantInt>(HEE->getOperand(1))->getSExtValue(); |
| INum = HEE->getOperand(0) == I1 ? 0 : 1; |
| } else { |
| Idx = HSV->getMaskValue(i); |
| if (Idx < (int) HOpElem) { |
| INum = HSV->getOperand(0) == I1 ? 0 : 1; |
| } else { |
| Idx -= HOpElem; |
| INum = HSV->getOperand(1) == I1 ? 0 : 1; |
| } |
| } |
| |
| II[i + numElemL] = std::pair<int, int>(Idx, INum); |
| } |
| |
| // We now have an array which tells us from which index of which |
| // input vector each element of the operand comes. |
| VectorType *I1T = cast<VectorType>(I1->getType()); |
| unsigned I1Elem = I1T->getNumElements(); |
| |
| if (!I2) { |
| // In this case there is only one underlying vector input. Check for |
| // the trivial case where we can use the input directly. |
| if (I1Elem == numElem) { |
| bool ElemInOrder = true; |
| for (unsigned i = 0; i < numElem; ++i) { |
| if (II[i].first != (int) i && II[i].first != -1) { |
| ElemInOrder = false; |
| break; |
| } |
| } |
| |
| if (ElemInOrder) |
| return I1; |
| } |
| |
| // A shuffle is needed. |
| std::vector<Constant *> Mask(numElem); |
| for (unsigned i = 0; i < numElem; ++i) { |
| int Idx = II[i].first; |
| if (Idx == -1) |
| Mask[i] = UndefValue::get(Type::getInt32Ty(Context)); |
| else |
| Mask[i] = ConstantInt::get(Type::getInt32Ty(Context), Idx); |
| } |
| |
| Instruction *S = |
| new ShuffleVectorInst(I1, UndefValue::get(I1T), |
| ConstantVector::get(Mask), |
| getReplacementName(IBeforeJ ? I : J, |
| true, o)); |
| S->insertBefore(IBeforeJ ? J : I); |
| return S; |
| } |
| |
| VectorType *I2T = cast<VectorType>(I2->getType()); |
| unsigned I2Elem = I2T->getNumElements(); |
| |
| // This input comes from two distinct vectors. The first step is to |
| // make sure that both vectors are the same length. If not, the |
| // smaller one will need to grow before they can be shuffled together. |
| if (I1Elem < I2Elem) { |
| std::vector<Constant *> Mask(I2Elem); |
| unsigned v = 0; |
| for (; v < I1Elem; ++v) |
| Mask[v] = ConstantInt::get(Type::getInt32Ty(Context), v); |
| for (; v < I2Elem; ++v) |
| Mask[v] = UndefValue::get(Type::getInt32Ty(Context)); |
| |
| Instruction *NewI1 = |
| new ShuffleVectorInst(I1, UndefValue::get(I1T), |
| ConstantVector::get(Mask), |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, 1)); |
| NewI1->insertBefore(IBeforeJ ? J : I); |
| I1 = NewI1; |
| I1T = I2T; |
| I1Elem = I2Elem; |
| } else if (I1Elem > I2Elem) { |
| std::vector<Constant *> Mask(I1Elem); |
| unsigned v = 0; |
| for (; v < I2Elem; ++v) |
| Mask[v] = ConstantInt::get(Type::getInt32Ty(Context), v); |
| for (; v < I1Elem; ++v) |
| Mask[v] = UndefValue::get(Type::getInt32Ty(Context)); |
| |
| Instruction *NewI2 = |
| new ShuffleVectorInst(I2, UndefValue::get(I2T), |
| ConstantVector::get(Mask), |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, 1)); |
| NewI2->insertBefore(IBeforeJ ? J : I); |
| I2 = NewI2; |
| I2T = I1T; |
| I2Elem = I1Elem; |
| } |
| |
| // Now that both I1 and I2 are the same length we can shuffle them |
| // together (and use the result). |
| std::vector<Constant *> Mask(numElem); |
| for (unsigned v = 0; v < numElem; ++v) { |
| if (II[v].first == -1) { |
| Mask[v] = UndefValue::get(Type::getInt32Ty(Context)); |
| } else { |
| int Idx = II[v].first + II[v].second * I1Elem; |
| Mask[v] = ConstantInt::get(Type::getInt32Ty(Context), Idx); |
| } |
| } |
| |
| Instruction *NewOp = |
| new ShuffleVectorInst(I1, I2, ConstantVector::get(Mask), |
| getReplacementName(IBeforeJ ? I : J, true, o)); |
| NewOp->insertBefore(IBeforeJ ? J : I); |
| return NewOp; |
| } |
| } |
| |
| Type *ArgType = ArgTypeL; |
| if (numElemL < numElemH) { |
| if (numElemL == 1 && expandIEChain(Context, I, J, o, HOp, numElemH, |
| ArgTypeL, VArgType, IBeforeJ, 1)) { |
| // This is another short-circuit case: we're combining a scalar into |
| // a vector that is formed by an IE chain. We've just expanded the IE |
| // chain, now insert the scalar and we're done. |
| |
| Instruction *S = InsertElementInst::Create(HOp, LOp, CV0, |
| getReplacementName(IBeforeJ ? I : J, true, o)); |
| S->insertBefore(IBeforeJ ? J : I); |
| return S; |
| } else if (!expandIEChain(Context, I, J, o, LOp, numElemL, ArgTypeL, |
| ArgTypeH, IBeforeJ)) { |
| // The two vector inputs to the shuffle must be the same length, |
| // so extend the smaller vector to be the same length as the larger one. |
| Instruction *NLOp; |
| if (numElemL > 1) { |
| |
| std::vector<Constant *> Mask(numElemH); |
| unsigned v = 0; |
| for (; v < numElemL; ++v) |
| Mask[v] = ConstantInt::get(Type::getInt32Ty(Context), v); |
| for (; v < numElemH; ++v) |
| Mask[v] = UndefValue::get(Type::getInt32Ty(Context)); |
| |
| NLOp = new ShuffleVectorInst(LOp, UndefValue::get(ArgTypeL), |
| ConstantVector::get(Mask), |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, 1)); |
| } else { |
| NLOp = InsertElementInst::Create(UndefValue::get(ArgTypeH), LOp, CV0, |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, 1)); |
| } |
| |
| NLOp->insertBefore(IBeforeJ ? J : I); |
| LOp = NLOp; |
| } |
| |
| ArgType = ArgTypeH; |
| } else if (numElemL > numElemH) { |
| if (numElemH == 1 && expandIEChain(Context, I, J, o, LOp, numElemL, |
| ArgTypeH, VArgType, IBeforeJ)) { |
| Instruction *S = |
| InsertElementInst::Create(LOp, HOp, |
| ConstantInt::get(Type::getInt32Ty(Context), |
| numElemL), |
| getReplacementName(IBeforeJ ? I : J, |
| true, o)); |
| S->insertBefore(IBeforeJ ? J : I); |
| return S; |
| } else if (!expandIEChain(Context, I, J, o, HOp, numElemH, ArgTypeH, |
| ArgTypeL, IBeforeJ)) { |
| Instruction *NHOp; |
| if (numElemH > 1) { |
| std::vector<Constant *> Mask(numElemL); |
| unsigned v = 0; |
| for (; v < numElemH; ++v) |
| Mask[v] = ConstantInt::get(Type::getInt32Ty(Context), v); |
| for (; v < numElemL; ++v) |
| Mask[v] = UndefValue::get(Type::getInt32Ty(Context)); |
| |
| NHOp = new ShuffleVectorInst(HOp, UndefValue::get(ArgTypeH), |
| ConstantVector::get(Mask), |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, 1)); |
| } else { |
| NHOp = InsertElementInst::Create(UndefValue::get(ArgTypeL), HOp, CV0, |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, 1)); |
| } |
| |
| NHOp->insertBefore(IBeforeJ ? J : I); |
| HOp = NHOp; |
| } |
| } |
| |
| if (ArgType->isVectorTy()) { |
| unsigned numElem = cast<VectorType>(VArgType)->getNumElements(); |
| std::vector<Constant*> Mask(numElem); |
| for (unsigned v = 0; v < numElem; ++v) { |
| unsigned Idx = v; |
| // If the low vector was expanded, we need to skip the extra |
| // undefined entries. |
| if (v >= numElemL && numElemH > numElemL) |
| Idx += (numElemH - numElemL); |
| Mask[v] = ConstantInt::get(Type::getInt32Ty(Context), Idx); |
| } |
| |
| Instruction *BV = new ShuffleVectorInst(LOp, HOp, |
| ConstantVector::get(Mask), |
| getReplacementName(IBeforeJ ? I : J, true, o)); |
| BV->insertBefore(IBeforeJ ? J : I); |
| return BV; |
| } |
| |
| Instruction *BV1 = InsertElementInst::Create( |
| UndefValue::get(VArgType), LOp, CV0, |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, 1)); |
| BV1->insertBefore(IBeforeJ ? J : I); |
| Instruction *BV2 = InsertElementInst::Create(BV1, HOp, CV1, |
| getReplacementName(IBeforeJ ? I : J, |
| true, o, 2)); |
| BV2->insertBefore(IBeforeJ ? J : I); |
| return BV2; |
| } |
| |
| // This function creates an array of values that will be used as the inputs |
| // to the vector instruction that fuses I with J. |
| void BBVectorize::getReplacementInputsForPair(LLVMContext& Context, |
| Instruction *I, Instruction *J, |
| SmallVector<Value *, 3> &ReplacedOperands, |
| bool IBeforeJ) { |
| unsigned NumOperands = I->getNumOperands(); |
| |
| for (unsigned p = 0, o = NumOperands-1; p < NumOperands; ++p, --o) { |
| // Iterate backward so that we look at the store pointer |
| // first and know whether or not we need to flip the inputs. |
| |
| if (isa<LoadInst>(I) || (o == 1 && isa<StoreInst>(I))) { |
| // This is the pointer for a load/store instruction. |
| ReplacedOperands[o] = getReplacementPointerInput(Context, I, J, o); |
| continue; |
| } else if (isa<CallInst>(I)) { |
| Function *F = cast<CallInst>(I)->getCalledFunction(); |
| Intrinsic::ID IID = (Intrinsic::ID) F->getIntrinsicID(); |
| if (o == NumOperands-1) { |
| BasicBlock &BB = *I->getParent(); |
| |
| Module *M = BB.getParent()->getParent(); |
| Type *ArgTypeI = I->getType(); |
| Type *ArgTypeJ = J->getType(); |
| Type *VArgType = getVecTypeForPair(ArgTypeI, ArgTypeJ); |
| |
| ReplacedOperands[o] = Intrinsic::getDeclaration(M, IID, VArgType); |
| continue; |
| } else if (IID == Intrinsic::powi && o == 1) { |
| // The second argument of powi is a single integer and we've already |
| // checked that both arguments are equal. As a result, we just keep |
| // I's second argument. |
| ReplacedOperands[o] = I->getOperand(o); |
| continue; |
| } |
| } else if (isa<ShuffleVectorInst>(I) && o == NumOperands-1) { |
| ReplacedOperands[o] = getReplacementShuffleMask(Context, I, J); |
| continue; |
| } |
| |
| ReplacedOperands[o] = getReplacementInput(Context, I, J, o, IBeforeJ); |
| } |
| } |
| |
| // This function creates two values that represent the outputs of the |
| // original I and J instructions. These are generally vector shuffles |
| // or extracts. In many cases, these will end up being unused and, thus, |
| // eliminated by later passes. |
| void BBVectorize::replaceOutputsOfPair(LLVMContext& Context, Instruction *I, |
| Instruction *J, Instruction *K, |
| Instruction *&InsertionPt, |
| Instruction *&K1, Instruction *&K2) { |
| if (isa<StoreInst>(I)) { |
| AA->replaceWithNewValue(I, K); |
| AA->replaceWithNewValue(J, K); |
| } else { |
| Type *IType = I->getType(); |
| Type *JType = J->getType(); |
| |
| VectorType *VType = getVecTypeForPair(IType, JType); |
| unsigned numElem = VType->getNumElements(); |
| |
| unsigned numElemI, numElemJ; |
| if (IType->isVectorTy()) |
| numElemI = cast<VectorType>(IType)->getNumElements(); |
| else |
| numElemI = 1; |
| |
| if (JType->isVectorTy()) |
| numElemJ = cast<VectorType>(JType)->getNumElements(); |
| else |
| numElemJ = 1; |
| |
| if (IType->isVectorTy()) { |
| std::vector<Constant*> Mask1(numElemI), Mask2(numElemI); |
| for (unsigned v = 0; v < numElemI; ++v) { |
| Mask1[v] = ConstantInt::get(Type::getInt32Ty(Context), v); |
| Mask2[v] = ConstantInt::get(Type::getInt32Ty(Context), numElemJ+v); |
| } |
| |
| K1 = new ShuffleVectorInst(K, UndefValue::get(VType), |
| ConstantVector::get( Mask1), |
| getReplacementName(K, false, 1)); |
| } else { |
| Value *CV0 = ConstantInt::get(Type::getInt32Ty(Context), 0); |
| K1 = ExtractElementInst::Create(K, CV0, |
| getReplacementName(K, false, 1)); |
| } |
| |
| if (JType->isVectorTy()) { |
| std::vector<Constant*> Mask1(numElemJ), Mask2(numElemJ); |
| for (unsigned v = 0; v < numElemJ; ++v) { |
| Mask1[v] = ConstantInt::get(Type::getInt32Ty(Context), v); |
| Mask2[v] = ConstantInt::get(Type::getInt32Ty(Context), numElemI+v); |
| } |
| |
| K2 = new ShuffleVectorInst(K, UndefValue::get(VType), |
| ConstantVector::get( Mask2), |
| getReplacementName(K, false, 2)); |
| } else { |
| Value *CV1 = ConstantInt::get(Type::getInt32Ty(Context), numElem-1); |
| K2 = ExtractElementInst::Create(K, CV1, |
| getReplacementName(K, false, 2)); |
| } |
| |
| K1->insertAfter(K); |
| K2->insertAfter(K1); |
| InsertionPt = K2; |
| } |
| } |
| |
| // Move all uses of the function I (including pairing-induced uses) after J. |
| bool BBVectorize::canMoveUsesOfIAfterJ(BasicBlock &BB, |
| DenseSet<ValuePair> &LoadMoveSetPairs, |
| Instruction *I, Instruction *J) { |
| // Skip to the first instruction past I. |
| BasicBlock::iterator L = llvm::next(BasicBlock::iterator(I)); |
| |
| DenseSet<Value *> Users; |
| AliasSetTracker WriteSet(*AA); |
| for (; cast<Instruction>(L) != J; ++L) |
| (void) trackUsesOfI(Users, WriteSet, I, L, true, &LoadMoveSetPairs); |
| |
| assert(cast<Instruction>(L) == J && |
| "Tracking has not proceeded far enough to check for dependencies"); |
| // If J is now in the use set of I, then trackUsesOfI will return true |
| // and we have a dependency cycle (and the fusing operation must abort). |
| return !trackUsesOfI(Users, WriteSet, I, J, true, &LoadMoveSetPairs); |
| } |
| |
| // Move all uses of the function I (including pairing-induced uses) after J. |
| void BBVectorize::moveUsesOfIAfterJ(BasicBlock &BB, |
| DenseSet<ValuePair> &LoadMoveSetPairs, |
| Instruction *&InsertionPt, |
| Instruction *I, Instruction *J) { |
| // Skip to the first instruction past I. |
| BasicBlock::iterator L = llvm::next(BasicBlock::iterator(I)); |
| |
| DenseSet<Value *> Users; |
| AliasSetTracker WriteSet(*AA); |
| for (; cast<Instruction>(L) != J;) { |
| if (trackUsesOfI(Users, WriteSet, I, L, true, &LoadMoveSetPairs)) { |
| // Move this instruction |
| Instruction *InstToMove = L; ++L; |
| |
| DEBUG(dbgs() << "BBV: moving: " << *InstToMove << |
| " to after " << *InsertionPt << "\n"); |
| InstToMove->removeFromParent(); |
| InstToMove->insertAfter(InsertionPt); |
| InsertionPt = InstToMove; |
| } else { |
| ++L; |
| } |
| } |
| } |
| |
| // Collect all load instruction that are in the move set of a given first |
| // pair member. These loads depend on the first instruction, I, and so need |
| // to be moved after J (the second instruction) when the pair is fused. |
| void BBVectorize::collectPairLoadMoveSet(BasicBlock &BB, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseMap<Value *, std::vector<Value *> > &LoadMoveSet, |
| DenseSet<ValuePair> &LoadMoveSetPairs, |
| Instruction *I) { |
| // Skip to the first instruction past I. |
| BasicBlock::iterator L = llvm::next(BasicBlock::iterator(I)); |
| |
| DenseSet<Value *> Users; |
| AliasSetTracker WriteSet(*AA); |
| |
| // Note: We cannot end the loop when we reach J because J could be moved |
| // farther down the use chain by another instruction pairing. Also, J |
| // could be before I if this is an inverted input. |
| for (BasicBlock::iterator E = BB.end(); cast<Instruction>(L) != E; ++L) { |
| if (trackUsesOfI(Users, WriteSet, I, L)) { |
| if (L->mayReadFromMemory()) { |
| LoadMoveSet[L].push_back(I); |
| LoadMoveSetPairs.insert(ValuePair(L, I)); |
| } |
| } |
| } |
| } |
| |
| // In cases where both load/stores and the computation of their pointers |
| // are chosen for vectorization, we can end up in a situation where the |
| // aliasing analysis starts returning different query results as the |
| // process of fusing instruction pairs continues. Because the algorithm |
| // relies on finding the same use dags here as were found earlier, we'll |
| // need to precompute the necessary aliasing information here and then |
| // manually update it during the fusion process. |
| void BBVectorize::collectLoadMoveSet(BasicBlock &BB, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseMap<Value *, std::vector<Value *> > &LoadMoveSet, |
| DenseSet<ValuePair> &LoadMoveSetPairs) { |
| for (std::vector<Value *>::iterator PI = PairableInsts.begin(), |
| PIE = PairableInsts.end(); PI != PIE; ++PI) { |
| DenseMap<Value *, Value *>::iterator P = ChosenPairs.find(*PI); |
| if (P == ChosenPairs.end()) continue; |
| |
| Instruction *I = cast<Instruction>(P->first); |
| collectPairLoadMoveSet(BB, ChosenPairs, LoadMoveSet, |
| LoadMoveSetPairs, I); |
| } |
| } |
| |
| // When the first instruction in each pair is cloned, it will inherit its |
| // parent's metadata. This metadata must be combined with that of the other |
| // instruction in a safe way. |
| void BBVectorize::combineMetadata(Instruction *K, const Instruction *J) { |
| SmallVector<std::pair<unsigned, MDNode*>, 4> Metadata; |
| K->getAllMetadataOtherThanDebugLoc(Metadata); |
| for (unsigned i = 0, n = Metadata.size(); i < n; ++i) { |
| unsigned Kind = Metadata[i].first; |
| MDNode *JMD = J->getMetadata(Kind); |
| MDNode *KMD = Metadata[i].second; |
| |
| switch (Kind) { |
| default: |
| K->setMetadata(Kind, 0); // Remove unknown metadata |
| break; |
| case LLVMContext::MD_tbaa: |
| K->setMetadata(Kind, MDNode::getMostGenericTBAA(JMD, KMD)); |
| break; |
| case LLVMContext::MD_fpmath: |
| K->setMetadata(Kind, MDNode::getMostGenericFPMath(JMD, KMD)); |
| break; |
| } |
| } |
| } |
| |
| // This function fuses the chosen instruction pairs into vector instructions, |
| // taking care preserve any needed scalar outputs and, then, it reorders the |
| // remaining instructions as needed (users of the first member of the pair |
| // need to be moved to after the location of the second member of the pair |
| // because the vector instruction is inserted in the location of the pair's |
| // second member). |
| void BBVectorize::fuseChosenPairs(BasicBlock &BB, |
| std::vector<Value *> &PairableInsts, |
| DenseMap<Value *, Value *> &ChosenPairs, |
| DenseSet<ValuePair> &FixedOrderPairs, |
| DenseMap<VPPair, unsigned> &PairConnectionTypes, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairs, |
| DenseMap<ValuePair, std::vector<ValuePair> > &ConnectedPairDeps) { |
| LLVMContext& Context = BB.getContext(); |
| |
| // During the vectorization process, the order of the pairs to be fused |
| // could be flipped. So we'll add each pair, flipped, into the ChosenPairs |
| // list. After a pair is fused, the flipped pair is removed from the list. |
| DenseSet<ValuePair> FlippedPairs; |
| for (DenseMap<Value *, Value *>::iterator P = ChosenPairs.begin(), |
| E = ChosenPairs.end(); P != E; ++P) |
| FlippedPairs.insert(ValuePair(P->second, P->first)); |
| for (DenseSet<ValuePair>::iterator P = FlippedPairs.begin(), |
| E = FlippedPairs.end(); P != E; ++P) |
| ChosenPairs.insert(*P); |
| |
| DenseMap<Value *, std::vector<Value *> > LoadMoveSet; |
| DenseSet<ValuePair> LoadMoveSetPairs; |
| collectLoadMoveSet(BB, PairableInsts, ChosenPairs, |
| LoadMoveSet, LoadMoveSetPairs); |
| |
| DEBUG(dbgs() << "BBV: initial: \n" << BB << "\n"); |
| |
| for (BasicBlock::iterator PI = BB.getFirstInsertionPt(); PI != BB.end();) { |
| DenseMap<Value *, Value *>::iterator P = ChosenPairs.find(PI); |
| if (P == ChosenPairs.end()) { |
| ++PI; |
| continue; |
| } |
| |
| if (getDepthFactor(P->first) == 0) { |
| // These instructions are not really fused, but are tracked as though |
| // they are. Any case in which it would be interesting to fuse them |
| // will be taken care of by InstCombine. |
| --NumFusedOps; |
| ++PI; |
| continue; |
| } |
| |
| Instruction *I = cast<Instruction>(P->first), |
| *J = cast<Instruction>(P->second); |
| |
| DEBUG(dbgs() << "BBV: fusing: " << *I << |
| " <-> " << *J << "\n"); |
| |
| // Remove the pair and flipped pair from the list. |
| DenseMap<Value *, Value *>::iterator FP = ChosenPairs.find(P->second); |
| assert(FP != ChosenPairs.end() && "Flipped pair not found in list"); |
| ChosenPairs.erase(FP); |
| ChosenPairs.erase(P); |
| |
| if (!canMoveUsesOfIAfterJ(BB, LoadMoveSetPairs, I, J)) { |
| DEBUG(dbgs() << "BBV: fusion of: " << *I << |
| " <-> " << *J << |
| " aborted because of non-trivial dependency cycle\n"); |
| --NumFusedOps; |
| ++PI; |
| continue; |
| } |
| |
| // If the pair must have the other order, then flip it. |
| bool FlipPairOrder = FixedOrderPairs.count(ValuePair(J, I)); |
| if (!FlipPairOrder && !FixedOrderPairs.count(ValuePair(I, J))) { |
| // This pair does not have a fixed order, and so we might want to |
| // flip it if that will yield fewer shuffles. We count the number |
| // of dependencies connected via swaps, and those directly connected, |
| // and flip the order if the number of swaps is greater. |
| bool OrigOrder = true; |
| DenseMap<ValuePair, std::vector<ValuePair> >::iterator IJ = |
| ConnectedPairDeps.find(ValuePair(I, J)); |
| if (IJ == ConnectedPairDeps.end()) { |
| IJ = ConnectedPairDeps.find(ValuePair(J, I)); |
| OrigOrder = false; |
| } |
| |
| if (IJ != ConnectedPairDeps.end()) { |
| unsigned NumDepsDirect = 0, NumDepsSwap = 0; |
| for (std::vector<ValuePair>::iterator T = IJ->second.begin(), |
| TE = IJ->second.end(); T != TE; ++T) { |
| VPPair Q(IJ->first, *T); |
| DenseMap<VPPair, unsigned>::iterator R = |
| PairConnectionTypes.find(VPPair(Q.second, Q.first)); |
| assert(R != PairConnectionTypes.end() && |
| "Cannot find pair connection type"); |
| if (R->second == PairConnectionDirect) |
| ++NumDepsDirect; |
| else if (R->second == PairConnectionSwap) |
| ++NumDepsSwap; |
| } |
| |
| if (!OrigOrder) |
| std::swap(NumDepsDirect, NumDepsSwap); |
| |
| if (NumDepsSwap > NumDepsDirect) { |
| FlipPairOrder = true; |
| DEBUG(dbgs() << "BBV: reordering pair: " << *I << |
| " <-> " << *J << "\n"); |
| } |
| } |
| } |
| |
| Instruction *L = I, *H = J; |
| if (FlipPairOrder) |
| std::swap(H, L); |
| |
| // If the pair being fused uses the opposite order from that in the pair |
| // connection map, then we need to flip the types. |
| DenseMap<ValuePair, std::vector<ValuePair> >::iterator HL = |
| ConnectedPairs.find(ValuePair(H, L)); |
| if (HL != ConnectedPairs.end()) |
| for (std::vector<ValuePair>::iterator T = HL->second.begin(), |
| TE = HL->second.end(); T != TE; ++T) { |
| VPPair Q(HL->first, *T); |
| DenseMap<VPPair, unsigned>::iterator R = PairConnectionTypes.find(Q); |
| assert(R != PairConnectionTypes.end() && |
| "Cannot find pair connection type"); |
| if (R->second == PairConnectionDirect) |
| R->second = PairConnectionSwap; |
| else if (R->second == PairConnectionSwap) |
| R->second = PairConnectionDirect; |
| } |
| |
| bool LBeforeH = !FlipPairOrder; |
| unsigned NumOperands = I->getNumOperands(); |
| SmallVector<Value *, 3> ReplacedOperands(NumOperands); |
| getReplacementInputsForPair(Context, L, H, ReplacedOperands, |
| LBeforeH); |
| |
| // Make a copy of the original operation, change its type to the vector |
| // type and replace its operands with the vector operands. |
| Instruction *K = L->clone(); |
| if (L->hasName()) |
| K->takeName(L); |
| else if (H->hasName()) |
| K->takeName(H); |
| |
| if (!isa<StoreInst>(K)) |
| K->mutateType(getVecTypeForPair(L->getType(), H->getType())); |
| |
| combineMetadata(K, H); |
| K->intersectOptionalDataWith(H); |
| |
| for (unsigned o = 0; o < NumOperands; ++o) |
| K->setOperand(o, ReplacedOperands[o]); |
| |
| K->insertAfter(J); |
| |
| // Instruction insertion point: |
| Instruction *InsertionPt = K; |
| Instruction *K1 = 0, *K2 = 0; |
| replaceOutputsOfPair(Context, L, H, K, InsertionPt, K1, K2); |
| |
| // The use dag of the first original instruction must be moved to after |
| // the location of the second instruction. The entire use dag of the |
| // first instruction is disjoint from the input dag of the second |
| // (by definition), and so commutes with it. |
| |
| moveUsesOfIAfterJ(BB, LoadMoveSetPairs, InsertionPt, I, J); |
| |
| if (!isa<StoreInst>(I)) { |
| L->replaceAllUsesWith(K1); |
| H->replaceAllUsesWith(K2); |
| AA->replaceWithNewValue(L, K1); |
| AA->replaceWithNewValue(H, K2); |
| } |
| |
| // Instructions that may read from memory may be in the load move set. |
| // Once an instruction is fused, we no longer need its move set, and so |
| // the values of the map never need to be updated. However, when a load |
| // is fused, we need to merge the entries from both instructions in the |
| // pair in case those instructions were in the move set of some other |
| // yet-to-be-fused pair. The loads in question are the keys of the map. |
| if (I->mayReadFromMemory()) { |
| std::vector<ValuePair> NewSetMembers; |
| DenseMap<Value *, std::vector<Value *> >::iterator II = |
| LoadMoveSet.find(I); |
| if (II != LoadMoveSet.end()) |
| for (std::vector<Value *>::iterator N = II->second.begin(), |
| NE = II->second.end(); N != NE; ++N) |
| NewSetMembers.push_back(ValuePair(K, *N)); |
| DenseMap<Value *, std::vector<Value *> >::iterator JJ = |
| LoadMoveSet.find(J); |
| if (JJ != LoadMoveSet.end()) |
| for (std::vector<Value *>::iterator N = JJ->second.begin(), |
| NE = JJ->second.end(); N != NE; ++N) |
| NewSetMembers.push_back(ValuePair(K, *N)); |
| for (std::vector<ValuePair>::iterator A = NewSetMembers.begin(), |
| AE = NewSetMembers.end(); A != AE; ++A) { |
| LoadMoveSet[A->first].push_back(A->second); |
| LoadMoveSetPairs.insert(*A); |
| } |
| } |
| |
| // Before removing I, set the iterator to the next instruction. |
| PI = llvm::next(BasicBlock::iterator(I)); |
| if (cast<Instruction>(PI) == J) |
| ++PI; |
| |
| SE->forgetValue(I); |
| SE->forgetValue(J); |
| I->eraseFromParent(); |
| J->eraseFromParent(); |
| |
| DEBUG(if (PrintAfterEveryPair) dbgs() << "BBV: block is now: \n" << |
| BB << "\n"); |
| } |
| |
| DEBUG(dbgs() << "BBV: final: \n" << BB << "\n"); |
| } |
| } |
| |
| char BBVectorize::ID = 0; |
| static const char bb_vectorize_name[] = "Basic-Block Vectorization"; |
| INITIALIZE_PASS_BEGIN(BBVectorize, BBV_NAME, bb_vectorize_name, false, false) |
| INITIALIZE_AG_DEPENDENCY(AliasAnalysis) |
| INITIALIZE_AG_DEPENDENCY(TargetTransformInfo) |
| INITIALIZE_PASS_DEPENDENCY(DominatorTree) |
| INITIALIZE_PASS_DEPENDENCY(ScalarEvolution) |
| INITIALIZE_PASS_END(BBVectorize, BBV_NAME, bb_vectorize_name, false, false) |
| |
| BasicBlockPass *llvm::createBBVectorizePass(const VectorizeConfig &C) { |
| return new BBVectorize(C); |
| } |
| |
| bool |
| llvm::vectorizeBasicBlock(Pass *P, BasicBlock &BB, const VectorizeConfig &C) { |
| BBVectorize BBVectorizer(P, C); |
| return BBVectorizer.vectorizeBB(BB); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| VectorizeConfig::VectorizeConfig() { |
| VectorBits = ::VectorBits; |
| VectorizeBools = !::NoBools; |
| VectorizeInts = !::NoInts; |
| VectorizeFloats = !::NoFloats; |
| VectorizePointers = !::NoPointers; |
| VectorizeCasts = !::NoCasts; |
| VectorizeMath = !::NoMath; |
| VectorizeFMA = !::NoFMA; |
| VectorizeSelect = !::NoSelect; |
| VectorizeCmp = !::NoCmp; |
| VectorizeGEP = !::NoGEP; |
| VectorizeMemOps = !::NoMemOps; |
| AlignedOnly = ::AlignedOnly; |
| ReqChainDepth= ::ReqChainDepth; |
| SearchLimit = ::SearchLimit; |
| MaxCandPairsForCycleCheck = ::MaxCandPairsForCycleCheck; |
| SplatBreaksChain = ::SplatBreaksChain; |
| MaxInsts = ::MaxInsts; |
| MaxPairs = ::MaxPairs; |
| MaxIter = ::MaxIter; |
| Pow2LenOnly = ::Pow2LenOnly; |
| NoMemOpBoost = ::NoMemOpBoost; |
| FastDep = ::FastDep; |
| } |