diff options
author | Alexander Kornienko <alexfh@google.com> | 2013-03-14 10:51:38 +0000 |
---|---|---|
committer | Alexander Kornienko <alexfh@google.com> | 2013-03-14 10:51:38 +0000 |
commit | 647735c781c5b37061ee03d6e9e6c7dda92218e2 (patch) | |
tree | 5a5e56606d41060263048b5a5586b3d2380898ba /lib/Transforms/Vectorize | |
parent | 6aed25d93d1cfcde5809a73ffa7dc1b0d6396f66 (diff) | |
parent | f635ef401786c84df32090251a8cf45981ecca33 (diff) |
Updating branches/google/stable to r176857
git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/google/stable@177040 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Vectorize')
-rw-r--r-- | lib/Transforms/Vectorize/BBVectorize.cpp | 1108 | ||||
-rw-r--r-- | lib/Transforms/Vectorize/LoopVectorize.cpp | 2588 | ||||
-rw-r--r-- | lib/Transforms/Vectorize/LoopVectorize.h | 458 | ||||
-rw-r--r-- | lib/Transforms/Vectorize/Vectorize.cpp | 2 |
4 files changed, 2624 insertions, 1532 deletions
diff --git a/lib/Transforms/Vectorize/BBVectorize.cpp b/lib/Transforms/Vectorize/BBVectorize.cpp index a48229132b..17900dabbe 100644 --- a/lib/Transforms/Vectorize/BBVectorize.cpp +++ b/lib/Transforms/Vectorize/BBVectorize.cpp @@ -29,26 +29,25 @@ #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/Constants.h" -#include "llvm/DataLayout.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Function.h" -#include "llvm/Instructions.h" -#include "llvm/IntrinsicInst.h" -#include "llvm/Intrinsics.h" -#include "llvm/LLVMContext.h" -#include "llvm/Metadata.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/TargetTransformInfo.h" #include "llvm/Transforms/Utils/Local.h" -#include "llvm/Type.h" #include <algorithm> -#include <map> using namespace llvm; static cl::opt<bool> @@ -89,6 +88,10 @@ 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")); @@ -199,9 +202,7 @@ namespace { DT = &P->getAnalysis<DominatorTree>(); SE = &P->getAnalysis<ScalarEvolution>(); TD = P->getAnalysisIfAvailable<DataLayout>(); - TTI = IgnoreTargetInfo ? 0 : - P->getAnalysisIfAvailable<TargetTransformInfo>(); - VTTI = TTI ? TTI->getVectorTargetTransformInfo() : 0; + TTI = IgnoreTargetInfo ? 0 : &P->getAnalysis<TargetTransformInfo>(); } typedef std::pair<Value *, Value *> ValuePair; @@ -209,18 +210,12 @@ namespace { typedef std::pair<ValuePair, size_t> ValuePairWithDepth; typedef std::pair<ValuePair, ValuePair> VPPair; // A ValuePair pair typedef std::pair<VPPair, unsigned> VPPairWithType; - typedef std::pair<std::multimap<Value *, Value *>::iterator, - std::multimap<Value *, Value *>::iterator> VPIteratorPair; - typedef std::pair<std::multimap<ValuePair, ValuePair>::iterator, - std::multimap<ValuePair, ValuePair>::iterator> - VPPIteratorPair; AliasAnalysis *AA; DominatorTree *DT; ScalarEvolution *SE; DataLayout *TD; - TargetTransformInfo *TTI; - const VectorTargetTransformInfo *VTTI; + const TargetTransformInfo *TTI; // FIXME: const correct? @@ -228,7 +223,7 @@ namespace { bool getCandidatePairs(BasicBlock &BB, BasicBlock::iterator &Start, - std::multimap<Value *, Value *> &CandidatePairs, + DenseMap<Value *, std::vector<Value *> > &CandidatePairs, DenseSet<ValuePair> &FixedOrderPairs, DenseMap<ValuePair, int> &CandidatePairCostSavings, std::vector<Value *> &PairableInsts, bool NonPow2Len); @@ -242,33 +237,36 @@ namespace { PairConnectionSplat }; - void computeConnectedPairs(std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - DenseMap<VPPair, unsigned> &PairConnectionTypes); + 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, - std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - DenseSet<ValuePair> &PairableInstUsers); - - void choosePairs(std::multimap<Value *, Value *> &CandidatePairs, - DenseMap<ValuePair, int> &CandidatePairCostSavings, - std::vector<Value *> &PairableInsts, - DenseSet<ValuePair> &FixedOrderPairs, - DenseMap<VPPair, unsigned> &PairConnectionTypes, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - std::multimap<ValuePair, ValuePair> &ConnectedPairDeps, - DenseSet<ValuePair> &PairableInstUsers, - DenseMap<Value *, Value *>& ChosenPairs); + 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, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - std::multimap<ValuePair, ValuePair> &ConnectedPairDeps); + 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); @@ -280,56 +278,63 @@ namespace { bool trackUsesOfI(DenseSet<Value *> &Users, AliasSetTracker &WriteSet, Instruction *I, Instruction *J, bool UpdateUsers = true, - std::multimap<Value *, Value *> *LoadMoveSet = 0); + DenseSet<ValuePair> *LoadMoveSetPairs = 0); - void computePairsConnectedTo( - std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - DenseMap<VPPair, unsigned> &PairConnectionTypes, - ValuePair P); + 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, - std::multimap<ValuePair, ValuePair> *PairableInstUserMap = 0); + DenseSet<ValuePair> &PairableInstUsers, + DenseMap<ValuePair, std::vector<ValuePair> > + *PairableInstUserMap = 0, + DenseSet<VPPair> *PairableInstUserPairSet = 0); bool pairWillFormCycle(ValuePair P, - std::multimap<ValuePair, ValuePair> &PairableInstUsers, - DenseSet<ValuePair> &CurrentPairs); - - void pruneTreeFor( - std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - DenseSet<ValuePair> &PairableInstUsers, - std::multimap<ValuePair, ValuePair> &PairableInstUserMap, - DenseMap<Value *, Value *> &ChosenPairs, - DenseMap<ValuePair, size_t> &Tree, - DenseSet<ValuePair> &PrunedTree, ValuePair J, - bool UseCycleCheck); - - void buildInitialTreeFor( - std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - DenseSet<ValuePair> &PairableInstUsers, - DenseMap<Value *, Value *> &ChosenPairs, - DenseMap<ValuePair, size_t> &Tree, ValuePair J); - - void findBestTreeFor( - std::multimap<Value *, Value *> &CandidatePairs, - DenseMap<ValuePair, int> &CandidatePairCostSavings, - std::vector<Value *> &PairableInsts, - DenseSet<ValuePair> &FixedOrderPairs, - DenseMap<VPPair, unsigned> &PairConnectionTypes, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - std::multimap<ValuePair, ValuePair> &ConnectedPairDeps, - DenseSet<ValuePair> &PairableInstUsers, - std::multimap<ValuePair, ValuePair> &PairableInstUserMap, - DenseMap<Value *, Value *> &ChosenPairs, - DenseSet<ValuePair> &BestTree, size_t &BestMaxDepth, - int &BestEffSize, VPIteratorPair ChoiceRange, - bool UseCycleCheck); + 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); @@ -361,20 +366,22 @@ namespace { void collectPairLoadMoveSet(BasicBlock &BB, DenseMap<Value *, Value *> &ChosenPairs, - std::multimap<Value *, Value *> &LoadMoveSet, + DenseMap<Value *, std::vector<Value *> > &LoadMoveSet, + DenseSet<ValuePair> &LoadMoveSetPairs, Instruction *I); void collectLoadMoveSet(BasicBlock &BB, std::vector<Value *> &PairableInsts, DenseMap<Value *, Value *> &ChosenPairs, - std::multimap<Value *, Value *> &LoadMoveSet); + DenseMap<Value *, std::vector<Value *> > &LoadMoveSet, + DenseSet<ValuePair> &LoadMoveSetPairs); bool canMoveUsesOfIAfterJ(BasicBlock &BB, - std::multimap<Value *, Value *> &LoadMoveSet, + DenseSet<ValuePair> &LoadMoveSetPairs, Instruction *I, Instruction *J); void moveUsesOfIAfterJ(BasicBlock &BB, - std::multimap<Value *, Value *> &LoadMoveSet, + DenseSet<ValuePair> &LoadMoveSetPairs, Instruction *&InsertionPt, Instruction *I, Instruction *J); @@ -387,7 +394,7 @@ namespace { return false; } - DEBUG(if (VTTI) dbgs() << "BBV: using target information\n"); + 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, @@ -395,7 +402,7 @@ namespace { // target vector register. unsigned n = 1; for (unsigned v = 2; - (VTTI || v <= Config.VectorBits) && + (TTI || v <= Config.VectorBits) && (!Config.MaxIter || n <= Config.MaxIter); v *= 2, ++n) { DEBUG(dbgs() << "BBV: fusing loop #" << n << @@ -426,9 +433,7 @@ namespace { DT = &getAnalysis<DominatorTree>(); SE = &getAnalysis<ScalarEvolution>(); TD = getAnalysisIfAvailable<DataLayout>(); - TTI = IgnoreTargetInfo ? 0 : - getAnalysisIfAvailable<TargetTransformInfo>(); - VTTI = TTI ? TTI->getVectorTargetTransformInfo() : 0; + TTI = IgnoreTargetInfo ? 0 : &getAnalysis<TargetTransformInfo>(); return vectorizeBB(BB); } @@ -438,6 +443,7 @@ namespace { AU.addRequired<AliasAnalysis>(); AU.addRequired<DominatorTree>(); AU.addRequired<ScalarEvolution>(); + AU.addRequired<TargetTransformInfo>(); AU.addPreserved<AliasAnalysis>(); AU.addPreserved<DominatorTree>(); AU.addPreserved<ScalarEvolution>(); @@ -467,18 +473,18 @@ namespace { static inline void getInstructionTypes(Instruction *I, Type *&T1, Type *&T2) { - if (isa<StoreInst>(I)) { + 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 = cast<StoreInst>(I)->getValueOperand(); + Value *IVal = SI->getValueOperand(); T1 = IVal->getType(); } else { T1 = I->getType(); } - if (I->isCast()) - T2 = cast<CastInst>(I)->getSrcTy(); + if (CastInst *CI = dyn_cast<CastInst>(I)) + T2 = CI->getSrcTy(); else T2 = T1; @@ -504,7 +510,7 @@ namespace { // 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 trees in the next iteration. Thus, giving them a + // 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 @@ -520,7 +526,7 @@ namespace { return 1; } - // Returns the cost of the provided instruction using VTTI. + // 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) { @@ -531,7 +537,7 @@ namespace { // generate vector GEPs. return 0; case Instruction::Br: - return VTTI->getCFInstrCost(Opcode); + return TTI->getCFInstrCost(Opcode); case Instruction::PHI: return 0; case Instruction::Add: @@ -552,11 +558,11 @@ namespace { case Instruction::And: case Instruction::Or: case Instruction::Xor: - return VTTI->getArithmeticInstrCost(Opcode, T1); + return TTI->getArithmeticInstrCost(Opcode, T1); case Instruction::Select: case Instruction::ICmp: case Instruction::FCmp: - return VTTI->getCmpSelInstrCost(Opcode, T1, T2); + return TTI->getCmpSelInstrCost(Opcode, T1, T2); case Instruction::ZExt: case Instruction::SExt: case Instruction::FPToUI: @@ -570,7 +576,7 @@ namespace { case Instruction::FPTrunc: case Instruction::BitCast: case Instruction::ShuffleVector: - return VTTI->getCastInstrCost(Opcode, T1, T2); + return TTI->getCastInstrCost(Opcode, T1, T2); } return 1; @@ -642,7 +648,7 @@ namespace { Function *F = I->getCalledFunction(); if (!F) return false; - unsigned IID = F->getIntrinsicID(); + Intrinsic::ID IID = (Intrinsic::ID) F->getIntrinsicID(); if (!IID) return false; switch(IID) { @@ -660,23 +666,11 @@ namespace { case Intrinsic::pow: return Config.VectorizeMath; case Intrinsic::fma: + case Intrinsic::fmuladd: return Config.VectorizeFMA; } } - // Returns true if J is the second element in some pair referenced by - // some multimap pair iterator pair. - template <typename V> - bool isSecondInIteratorPair(V J, std::pair< - typename std::multimap<V, V>::iterator, - typename std::multimap<V, V>::iterator> PairRange) { - for (typename std::multimap<V, V>::iterator K = PairRange.first; - K != PairRange.second; ++K) - if (K->second == J) return true; - - return false; - } - bool isPureIEChain(InsertElementInst *IE) { InsertElementInst *IENext = IE; do { @@ -701,11 +695,12 @@ namespace { DenseMap<Value *, Value *> AllChosenPairs; DenseSet<ValuePair> AllFixedOrderPairs; DenseMap<VPPair, unsigned> AllPairConnectionTypes; - std::multimap<ValuePair, ValuePair> AllConnectedPairs, AllConnectedPairDeps; + DenseMap<ValuePair, std::vector<ValuePair> > AllConnectedPairs, + AllConnectedPairDeps; do { std::vector<Value *> PairableInsts; - std::multimap<Value *, Value *> CandidatePairs; + DenseMap<Value *, std::vector<Value *> > CandidatePairs; DenseSet<ValuePair> FixedOrderPairs; DenseMap<ValuePair, int> CandidatePairCostSavings; ShouldContinue = getCandidatePairs(BB, Start, CandidatePairs, @@ -714,6 +709,14 @@ namespace { 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 @@ -723,30 +726,33 @@ namespace { // Note that it only matters that both members of the second pair use some // element of the first pair (to allow for splatting). - std::multimap<ValuePair, ValuePair> ConnectedPairs, ConnectedPairDeps; + DenseMap<ValuePair, std::vector<ValuePair> > ConnectedPairs, + ConnectedPairDeps; DenseMap<VPPair, unsigned> PairConnectionTypes; - computeConnectedPairs(CandidatePairs, PairableInsts, ConnectedPairs, - PairConnectionTypes); + computeConnectedPairs(CandidatePairs, CandidatePairsSet, + PairableInsts, ConnectedPairs, PairConnectionTypes); if (ConnectedPairs.empty()) continue; - for (std::multimap<ValuePair, ValuePair>::iterator + for (DenseMap<ValuePair, std::vector<ValuePair> >::iterator I = ConnectedPairs.begin(), IE = ConnectedPairs.end(); - I != IE; ++I) { - ConnectedPairDeps.insert(VPPair(I->second, I->first)); - } + 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 tree meeting the depth requirement on at - // least one branch. Then select all pairings that are part of that tree + // 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, CandidatePairCostSavings, + choosePairs(CandidatePairs, CandidatePairsSet, + CandidatePairCostSavings, PairableInsts, FixedOrderPairs, PairConnectionTypes, ConnectedPairs, ConnectedPairDeps, PairableInstUsers, ChosenPairs); @@ -780,14 +786,15 @@ namespace { } } - for (std::multimap<ValuePair, ValuePair>::iterator + for (DenseMap<ValuePair, std::vector<ValuePair> >::iterator I = ConnectedPairs.begin(), IE = ConnectedPairs.end(); - I != IE; ++I) { - if (AllPairConnectionTypes.count(*I)) { - AllConnectedPairs.insert(*I); - AllConnectedPairDeps.insert(VPPair(I->second, I->first)); - } - } + 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; @@ -903,8 +910,8 @@ namespace { T2->getScalarType()->isPointerTy())) return false; - if (!VTTI && (T1->getPrimitiveSizeInBits() >= Config.VectorBits || - T2->getPrimitiveSizeInBits() >= Config.VectorBits)) + if (!TTI && (T1->getPrimitiveSizeInBits() >= Config.VectorBits || + T2->getPrimitiveSizeInBits() >= Config.VectorBits)) return false; return true; @@ -913,7 +920,7 @@ namespace { // 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 tree of I. + // in the use dag of I. bool BBVectorize::areInstsCompatible(Instruction *I, Instruction *J, bool IsSimpleLoadStore, bool NonPow2Len, int &CostSavings, int &FixedOrder) { @@ -935,7 +942,7 @@ namespace { unsigned MaxTypeBits = std::max( IT1->getPrimitiveSizeInBits() + JT1->getPrimitiveSizeInBits(), IT2->getPrimitiveSizeInBits() + JT2->getPrimitiveSizeInBits()); - if (!VTTI && MaxTypeBits > Config.VectorBits) + if (!TTI && MaxTypeBits > Config.VectorBits) return false; // FIXME: handle addsub-type operations! @@ -967,21 +974,26 @@ namespace { return false; } - if (VTTI) { - unsigned ICost = VTTI->getMemoryOpCost(I->getOpcode(), I->getType(), - IAlignment, IAddressSpace); - unsigned JCost = VTTI->getMemoryOpCost(J->getOpcode(), J->getType(), - JAlignment, JAddressSpace); - unsigned VCost = VTTI->getMemoryOpCost(I->getOpcode(), VType, - BottomAlignment, - IAddressSpace); + 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 = VTTI->getNumberOfParts(VType); + unsigned VParts = TTI->getNumberOfParts(VType); if (VParts > 1) return false; else if (!VParts && VCost == ICost + JCost) @@ -992,11 +1004,17 @@ namespace { } else { return false; } - } else if (VTTI) { + } 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) @@ -1005,8 +1023,8 @@ namespace { // 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 = VTTI->getNumberOfParts(VT1), - VParts2 = VTTI->getNumberOfParts(VT2); + unsigned VParts1 = TTI->getNumberOfParts(VT1), + VParts2 = TTI->getNumberOfParts(VT2); if (VParts1 > 1 || VParts2 > 1) return false; else if ((!VParts1 || !VParts2) && VCost == ICost + JCost) @@ -1019,14 +1037,67 @@ namespace { // vectorized, the second arguments must be equal. CallInst *CI = dyn_cast<CallInst>(I); Function *FI; - if (CI && (FI = CI->getCalledFunction()) && - FI->getIntrinsicID() == 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 (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; @@ -1040,7 +1111,7 @@ namespace { // 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 multimap + // 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 @@ -1050,7 +1121,7 @@ namespace { bool BBVectorize::trackUsesOfI(DenseSet<Value *> &Users, AliasSetTracker &WriteSet, Instruction *I, Instruction *J, bool UpdateUsers, - std::multimap<Value *, Value *> *LoadMoveSet) { + DenseSet<ValuePair> *LoadMoveSetPairs) { bool UsesI = false; // This instruction may already be marked as a user due, for example, to @@ -1068,9 +1139,8 @@ namespace { } } if (!UsesI && J->mayReadFromMemory()) { - if (LoadMoveSet) { - VPIteratorPair JPairRange = LoadMoveSet->equal_range(J); - UsesI = isSecondInIteratorPair<Value*>(I, JPairRange); + if (LoadMoveSetPairs) { + UsesI = LoadMoveSetPairs->count(ValuePair(J, I)); } else { for (AliasSetTracker::iterator W = WriteSet.begin(), WE = WriteSet.end(); W != WE; ++W) { @@ -1094,10 +1164,11 @@ namespace { // basic block and collects all candidate pairs for vectorization. bool BBVectorize::getCandidatePairs(BasicBlock &BB, BasicBlock::iterator &Start, - std::multimap<Value *, Value *> &CandidatePairs, + 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; @@ -1143,8 +1214,9 @@ namespace { PairableInsts.push_back(I); } - CandidatePairs.insert(ValuePair(I, J)); - if (VTTI) + CandidatePairs[I].push_back(J); + ++TotalPairs; + if (TTI) CandidatePairCostSavings.insert(ValuePairWithCost(ValuePair(I, J), CostSavings)); @@ -1167,7 +1239,8 @@ namespace { // 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) { + if (PairableInsts.size() >= Config.MaxInsts || + TotalPairs >= Config.MaxPairs) { ShouldContinue = true; break; } @@ -1187,11 +1260,12 @@ namespace { // it looks for pairs such that both members have an input which is an // output of PI or PJ. void BBVectorize::computePairsConnectedTo( - std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - DenseMap<VPPair, unsigned> &PairConnectionTypes, - ValuePair P) { + 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 @@ -1209,8 +1283,6 @@ namespace { continue; } - VPIteratorPair IPairRange = CandidatePairs.equal_range(*I); - // For each use of the first variable, look for uses of the second // variable... for (Value::use_iterator J = P.second->use_begin(), @@ -1219,19 +1291,17 @@ namespace { P.second == SJ->getPointerOperand()) continue; - VPIteratorPair JPairRange = CandidatePairs.equal_range(*J); - // Look for <I, J>: - if (isSecondInIteratorPair<Value*>(*J, IPairRange)) { + if (CandidatePairsSet.count(ValuePair(*I, *J))) { VPPair VP(P, ValuePair(*I, *J)); - ConnectedPairs.insert(VP); + ConnectedPairs[VP.first].push_back(VP.second); PairConnectionTypes.insert(VPPairWithType(VP, PairConnectionDirect)); } // Look for <J, I>: - if (isSecondInIteratorPair<Value*>(*I, JPairRange)) { + if (CandidatePairsSet.count(ValuePair(*J, *I))) { VPPair VP(P, ValuePair(*J, *I)); - ConnectedPairs.insert(VP); + ConnectedPairs[VP.first].push_back(VP.second); PairConnectionTypes.insert(VPPairWithType(VP, PairConnectionSwap)); } } @@ -1244,9 +1314,9 @@ namespace { P.first == SJ->getPointerOperand()) continue; - if (isSecondInIteratorPair<Value*>(*J, IPairRange)) { + if (CandidatePairsSet.count(ValuePair(*I, *J))) { VPPair VP(P, ValuePair(*I, *J)); - ConnectedPairs.insert(VP); + ConnectedPairs[VP.first].push_back(VP.second); PairConnectionTypes.insert(VPPairWithType(VP, PairConnectionSplat)); } } @@ -1263,16 +1333,14 @@ namespace { P.second == SI->getPointerOperand()) continue; - VPIteratorPair IPairRange = CandidatePairs.equal_range(*I); - for (Value::use_iterator J = P.second->use_begin(); J != E; ++J) { if ((SJ = dyn_cast<StoreInst>(*J)) && P.second == SJ->getPointerOperand()) continue; - if (isSecondInIteratorPair<Value*>(*J, IPairRange)) { + if (CandidatePairsSet.count(ValuePair(*I, *J))) { VPPair VP(P, ValuePair(*I, *J)); - ConnectedPairs.insert(VP); + ConnectedPairs[VP.first].push_back(VP.second); PairConnectionTypes.insert(VPPairWithType(VP, PairConnectionSplat)); } } @@ -1283,55 +1351,73 @@ namespace { // connected if some output of the first pair forms an input to both members // of the second pair. void BBVectorize::computeConnectedPairs( - std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - DenseMap<VPPair, unsigned> &PairConnectionTypes) { - + 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) { - VPIteratorPair choiceRange = CandidatePairs.equal_range(*PI); + DenseMap<Value *, std::vector<Value *> >::iterator PP = + CandidatePairs.find(*PI); + if (PP == CandidatePairs.end()) + continue; - for (std::multimap<Value *, Value *>::iterator P = choiceRange.first; - P != choiceRange.second; ++P) - computePairsConnectedTo(CandidatePairs, PairableInsts, - ConnectedPairs, PairConnectionTypes, *P); + 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(dbgs() << "BBV: found " << ConnectedPairs.size() + 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 tree of A. If B is in the use tree of A, then B + // 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, - std::multimap<Value *, Value *> &CandidatePairs, + DenseMap<Value *, std::vector<Value *> > &CandidatePairs, std::vector<Value *> &PairableInsts, DenseSet<ValuePair> &PairableInstUsers) { DenseSet<Value *> IsInPair; - for (std::multimap<Value *, Value *>::iterator C = CandidatePairs.begin(), - E = CandidatePairs.end(); C != E; ++C) { + for (DenseMap<Value *, std::vector<Value *> >::iterator C = + CandidatePairs.begin(), E = CandidatePairs.end(); C != E; ++C) { IsInPair.insert(C->first); - IsInPair.insert(C->second); + IsInPair.insert(C->second.begin(), C->second.end()); } - // Iterate through the basic block, recording all Users of each + // Iterate through the basic block, recording all users of each // pairable instruction. - BasicBlock::iterator E = BB.end(); + 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) + 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) + U != E; ++U) { + if (IsInPair.find(*U) == IsInPair.end()) continue; PairableInstUsers.insert(ValuePair(I, *U)); + } + + if (I == EL) + break; } } @@ -1339,8 +1425,9 @@ namespace { // 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, - std::multimap<ValuePair, ValuePair> *PairableInstUserMap) { + 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)) || @@ -1353,17 +1440,14 @@ namespace { 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 (same is true of - // most uses of std::multimap). + // profiling and probably a different data structure. if (PUsesQ) { - VPPIteratorPair QPairRange = PairableInstUserMap->equal_range(Q); - if (!isSecondInIteratorPair(P, QPairRange)) - PairableInstUserMap->insert(VPPair(Q, P)); + if (PairableInstUserPairSet->insert(VPPair(Q, P)).second) + (*PairableInstUserMap)[Q].push_back(P); } if (QUsesP) { - VPPIteratorPair PPairRange = PairableInstUserMap->equal_range(P); - if (!isSecondInIteratorPair(Q, PPairRange)) - PairableInstUserMap->insert(VPPair(P, Q)); + if (PairableInstUserPairSet->insert(VPPair(P, Q)).second) + (*PairableInstUserMap)[P].push_back(Q); } } @@ -1373,8 +1457,8 @@ namespace { // 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, - std::multimap<ValuePair, ValuePair> &PairableInstUserMap, - DenseSet<ValuePair> &CurrentPairs) { + DenseMap<ValuePair, std::vector<ValuePair> > &PairableInstUserMap, + DenseSet<ValuePair> &CurrentPairs) { DEBUG(if (DebugCycleCheck) dbgs() << "BBV: starting cycle check for : " << *P.first << " <-> " << *P.second << "\n"); @@ -1391,36 +1475,41 @@ namespace { DEBUG(if (DebugCycleCheck) dbgs() << "BBV: cycle check visiting: " << *QTop.first << " <-> " << *QTop.second << "\n"); - VPPIteratorPair QPairRange = PairableInstUserMap.equal_range(QTop); - for (std::multimap<ValuePair, ValuePair>::iterator C = QPairRange.first; - C != QPairRange.second; ++C) { - if (C->second == P) { + 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: " - << *C->first.first << " <-> " << *C->first.second << "\n"); + << QTop.first << " <-> " << C->second << "\n"); return true; } - if (CurrentPairs.count(C->second) && !Visited.count(C->second)) - Q.push_back(C->second); + if (CurrentPairs.count(*C) && !Visited.count(*C)) + Q.push_back(*C); } } while (!Q.empty()); return false; } - // This function builds the initial tree of connected pairs with the + // This function builds the initial dag of connected pairs with the // pair J at the root. - void BBVectorize::buildInitialTreeFor( - std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - DenseSet<ValuePair> &PairableInstUsers, - DenseMap<Value *, Value *> &ChosenPairs, - DenseMap<ValuePair, size_t> &Tree, ValuePair J) { - // Each of these pairs is viewed as the root node of a Tree. The Tree + 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 Tree and the maximum depth of the Tree. + // 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))); @@ -1430,69 +1519,65 @@ namespace { // Push each child onto the queue: bool MoreChildren = false; size_t MaxChildDepth = QTop.second; - VPPIteratorPair qtRange = ConnectedPairs.equal_range(QTop.first); - for (std::multimap<ValuePair, ValuePair>::iterator k = qtRange.first; - k != qtRange.second; ++k) { - // Make sure that this child pair is still a candidate: - bool IsStillCand = false; - VPIteratorPair checkRange = - CandidatePairs.equal_range(k->second.first); - for (std::multimap<Value *, Value *>::iterator m = checkRange.first; - m != checkRange.second; ++m) { - if (m->second == k->second.second) { - IsStillCand = true; - break; - } - } - - if (IsStillCand) { - DenseMap<ValuePair, size_t>::iterator C = Tree.find(k->second); - if (C == Tree.end()) { - size_t d = getDepthFactor(k->second.first); - Q.push_back(ValuePairWithDepth(k->second, QTop.second+d)); - MoreChildren = true; - } else { - MaxChildDepth = std::max(MaxChildDepth, C->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 Tree: - Tree.insert(ValuePairWithDepth(QTop.first, MaxChildDepth)); + // Record the current pair as part of the DAG: + DAG.insert(ValuePairWithDepth(QTop.first, MaxChildDepth)); Q.pop_back(); } } while (!Q.empty()); } - // Given some initial tree, prune it by removing conflicting pairs (pairs + // Given some initial dag, prune it by removing conflicting pairs (pairs // that cannot be simultaneously chosen for vectorization). - void BBVectorize::pruneTreeFor( - std::multimap<Value *, Value *> &CandidatePairs, - std::vector<Value *> &PairableInsts, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - DenseSet<ValuePair> &PairableInstUsers, - std::multimap<ValuePair, ValuePair> &PairableInstUserMap, - DenseMap<Value *, Value *> &ChosenPairs, - DenseMap<ValuePair, size_t> &Tree, - DenseSet<ValuePair> &PrunedTree, ValuePair J, - bool UseCycleCheck) { + 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(); - PrunedTree.insert(QTop.first); + PrunedDAG.insert(QTop.first); // Visit each child, pruning as necessary... SmallVector<ValuePairWithDepth, 8> BestChildren; - VPPIteratorPair QTopRange = ConnectedPairs.equal_range(QTop.first); - for (std::multimap<ValuePair, ValuePair>::iterator K = QTopRange.first; - K != QTopRange.second; ++K) { - DenseMap<ValuePair, size_t>::iterator C = Tree.find(K->second); - if (C == Tree.end()) continue; + 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 Tree, now we need to make sure it is the + // 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. @@ -1506,7 +1591,7 @@ namespace { // 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 Tree is not + // 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 @@ -1525,7 +1610,8 @@ namespace { C2->first.second == C->first.first || C2->first.second == C->first.second || pairsConflict(C2->first, C->first, PairableInstUsers, - UseCycleCheck ? &PairableInstUserMap : 0)) { + UseCycleCheck ? &PairableInstUserMap : 0, + UseCycleCheck ? &PairableInstUserPairSet : 0)) { if (C2->second >= C->second) { CanAdd = false; break; @@ -1537,15 +1623,16 @@ namespace { if (!CanAdd) continue; // Even worse, this child could conflict with another node already - // selected for the Tree. If that is the case, ignore this child. - for (DenseSet<ValuePair>::iterator T = PrunedTree.begin(), - E2 = PrunedTree.end(); T != E2; ++T) { + // 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 ? &PairableInstUserMap : 0, + UseCycleCheck ? &PairableInstUserPairSet : 0)) { CanAdd = false; break; } @@ -1562,7 +1649,8 @@ namespace { C2->first.second == C->first.first || C2->first.second == C->first.second || pairsConflict(C2->first, C->first, PairableInstUsers, - UseCycleCheck ? &PairableInstUserMap : 0)) { + UseCycleCheck ? &PairableInstUserMap : 0, + UseCycleCheck ? &PairableInstUserPairSet : 0)) { CanAdd = false; break; } @@ -1577,7 +1665,8 @@ namespace { ChosenPairs.begin(), E2 = ChosenPairs.end(); C2 != E2; ++C2) { if (pairsConflict(*C2, C->first, PairableInstUsers, - UseCycleCheck ? &PairableInstUserMap : 0)) { + UseCycleCheck ? &PairableInstUserMap : 0, + UseCycleCheck ? &PairableInstUserPairSet : 0)) { CanAdd = false; break; } @@ -1589,7 +1678,7 @@ namespace { // 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 tree to see if we again reach the current pair. If we + // 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 @@ -1626,34 +1715,40 @@ namespace { } while (!Q.empty()); } - // This function finds the best tree of mututally-compatible connected + // This function finds the best dag of mututally-compatible connected // pairs, given the choice of root pairs as an iterator range. - void BBVectorize::findBestTreeFor( - std::multimap<Value *, Value *> &CandidatePairs, - DenseMap<ValuePair, int> &CandidatePairCostSavings, - std::vector<Value *> &PairableInsts, - DenseSet<ValuePair> &FixedOrderPairs, - DenseMap<VPPair, unsigned> &PairConnectionTypes, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - std::multimap<ValuePair, ValuePair> &ConnectedPairDeps, - DenseSet<ValuePair> &PairableInstUsers, - std::multimap<ValuePair, ValuePair> &PairableInstUserMap, - DenseMap<Value *, Value *> &ChosenPairs, - DenseSet<ValuePair> &BestTree, size_t &BestMaxDepth, - int &BestEffSize, VPIteratorPair ChoiceRange, - bool UseCycleCheck) { - for (std::multimap<Value *, Value *>::iterator J = ChoiceRange.first; - J != ChoiceRange.second; ++J) { + 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 Tree pruning for more details). + // 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, *J, PairableInstUsers, - UseCycleCheck ? &PairableInstUserMap : 0)) { + if (pairsConflict(*C, IJ, PairableInstUsers, + UseCycleCheck ? &PairableInstUserMap : 0, + UseCycleCheck ? &PairableInstUserPairSet : 0)) { DoesConflict = true; break; } @@ -1663,40 +1758,42 @@ namespace { if (DoesConflict) continue; if (UseCycleCheck && - pairWillFormCycle(*J, PairableInstUserMap, ChosenPairSet)) + pairWillFormCycle(IJ, PairableInstUserMap, ChosenPairSet)) continue; - DenseMap<ValuePair, size_t> Tree; - buildInitialTreeFor(CandidatePairs, PairableInsts, ConnectedPairs, - PairableInstUsers, ChosenPairs, Tree, *J); + 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 Tree. - size_t MaxDepth = Tree.lookup(*J); + // depth is still the same in the unpruned DAG. + size_t MaxDepth = DAG.lookup(IJ); - DEBUG(if (DebugPairSelection) dbgs() << "BBV: found Tree for pair {" - << *J->first << " <-> " << *J->second << "} of depth " << - MaxDepth << " and size " << Tree.size() << "\n"); + 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 Tree has been constructed, but, may contain + // At this point the DAG has been constructed, but, may contain // contradictory children (meaning that different children of - // some tree node may be attempting to fuse the same instruction). - // So now we walk the tree again, in the case of a conflict, + // 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> PrunedTree; - pruneTreeFor(CandidatePairs, PairableInsts, ConnectedPairs, - PairableInstUsers, PairableInstUserMap, ChosenPairs, Tree, - PrunedTree, *J, UseCycleCheck); + DenseSet<ValuePair> PrunedDAG; + pruneDAGFor(CandidatePairs, PairableInsts, ConnectedPairs, + PairableInstUsers, PairableInstUserMap, + PairableInstUserPairSet, + ChosenPairs, DAG, PrunedDAG, IJ, UseCycleCheck); int EffSize = 0; - if (VTTI) { - DenseSet<Value *> PrunedTreeInstrs; - for (DenseSet<ValuePair>::iterator S = PrunedTree.begin(), - E = PrunedTree.end(); S != E; ++S) { - PrunedTreeInstrs.insert(S->first); - PrunedTreeInstrs.insert(S->second); + 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. @@ -1709,8 +1806,8 @@ namespace { // The node weights represent the cost savings associated with // fusing the pair of instructions. - for (DenseSet<ValuePair>::iterator S = PrunedTree.begin(), - E = PrunedTree.end(); S != E; ++S) { + 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)) @@ -1728,15 +1825,17 @@ namespace { // The edge weights contribute in a negative sense: they represent // the cost of shuffles. - VPPIteratorPair IP = ConnectedPairDeps.equal_range(*S); - if (IP.first != ConnectedPairDeps.end()) { + DenseMap<ValuePair, std::vector<ValuePair> >::iterator SS = + ConnectedPairDeps.find(*S); + if (SS != ConnectedPairDeps.end()) { unsigned NumDepsDirect = 0, NumDepsSwap = 0; - for (std::multimap<ValuePair, ValuePair>::iterator Q = IP.first; - Q != IP.second; ++Q) { - if (!PrunedTree.count(Q->second)) + 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)); + PairConnectionTypes.find(VPPair(Q.second, Q.first)); assert(R != PairConnectionTypes.end() && "Cannot find pair connection type"); if (R->second == PairConnectionDirect) @@ -1752,24 +1851,35 @@ namespace { ((NumDepsSwap > NumDepsDirect) || FixedOrderPairs.count(ValuePair(S->second, S->first))); - for (std::multimap<ValuePair, ValuePair>::iterator Q = IP.first; - Q != IP.second; ++Q) { - if (!PrunedTree.count(Q->second)) + 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)); + 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 *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 << + *Q.second.first << " <-> " << *Q.second.second << "} -> {" << *S->first << " <-> " << *S->second << "} = " << ESContrib << "\n"); @@ -1796,7 +1906,7 @@ namespace { } if (isa<ExtractElementInst>(*I)) continue; - if (PrunedTreeInstrs.count(*I)) + if (PrunedDAGInstrs.count(*I)) continue; NeedsExtraction = true; break; @@ -1804,11 +1914,13 @@ namespace { if (NeedsExtraction) { int ESContrib; - if (Ty1->isVectorTy()) + if (Ty1->isVectorTy()) { ESContrib = (int) getInstrCost(Instruction::ShuffleVector, Ty1, VTy); - else - ESContrib = (int) VTTI->getVectorInstrCost( + 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 {" << @@ -1826,7 +1938,7 @@ namespace { } if (isa<ExtractElementInst>(*I)) continue; - if (PrunedTreeInstrs.count(*I)) + if (PrunedDAGInstrs.count(*I)) continue; NeedsExtraction = true; break; @@ -1834,11 +1946,14 @@ namespace { if (NeedsExtraction) { int ESContrib; - if (Ty2->isVectorTy()) + if (Ty2->isVectorTy()) { ESContrib = (int) getInstrCost(Instruction::ShuffleVector, Ty2, VTy); - else - ESContrib = (int) VTTI->getVectorInstrCost( + 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"); @@ -1865,7 +1980,7 @@ namespace { ValuePair VPR = ValuePair(O2, O1); // Internal edges are not handled here. - if (PrunedTree.count(VP) || PrunedTree.count(VPR)) + if (PrunedDAG.count(VP) || PrunedDAG.count(VPR)) continue; Type *Ty1 = O1->getType(), @@ -1913,22 +2028,26 @@ namespace { } 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) VTTI->getVectorInstrCost( + ESContrib = (int) TTI->getVectorInstrCost( Instruction::InsertElement, VTy, 0); - ESContrib += (int) VTTI->getVectorInstrCost( + 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) VTTI->getVectorInstrCost( + 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) VTTI->getVectorInstrCost( + ESContrib = (int) TTI->getVectorInstrCost( Instruction::InsertElement, Ty1, 0); ESContrib += (int) getInstrCost(Instruction::ShuffleVector, VTy, Ty1); @@ -1955,27 +2074,27 @@ namespace { if (!HasNontrivialInsts) { DEBUG(if (DebugPairSelection) dbgs() << - "\tNo non-trivial instructions in tree;" + "\tNo non-trivial instructions in DAG;" " override to zero effective size\n"); EffSize = 0; } } else { - for (DenseSet<ValuePair>::iterator S = PrunedTree.begin(), - E = PrunedTree.end(); S != E; ++S) + 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 Tree for pair {" - << *J->first << " <-> " << *J->second << "} of depth " << - MaxDepth << " and size " << PrunedTree.size() << + dbgs() << "BBV: found pruned DAG for pair {" + << *IJ.first << " <-> " << *IJ.second << "} of depth " << + MaxDepth << " and size " << PrunedDAG.size() << " (effective size: " << EffSize << ")\n"); - if (((VTTI && !UseChainDepthWithTI) || + if (((TTI && !UseChainDepthWithTI) || MaxDepth >= Config.ReqChainDepth) && EffSize > 0 && EffSize > BestEffSize) { BestMaxDepth = MaxDepth; BestEffSize = EffSize; - BestTree = PrunedTree; + BestDAG = PrunedDAG; } } } @@ -1983,66 +2102,98 @@ namespace { // Given the list of candidate pairs, this function selects those // that will be fused into vector instructions. void BBVectorize::choosePairs( - std::multimap<Value *, Value *> &CandidatePairs, - DenseMap<ValuePair, int> &CandidatePairCostSavings, - std::vector<Value *> &PairableInsts, - DenseSet<ValuePair> &FixedOrderPairs, - DenseMap<VPPair, unsigned> &PairConnectionTypes, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - std::multimap<ValuePair, ValuePair> &ConnectedPairDeps, - DenseSet<ValuePair> &PairableInstUsers, - DenseMap<Value *, Value *>& ChosenPairs) { + 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 = - CandidatePairs.size() <= Config.MaxCandPairsForCycleCheck; - std::multimap<ValuePair, ValuePair> PairableInstUserMap; + 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.count(*I); + size_t NumChoices = CandidatePairs.lookup(*I).size(); if (!NumChoices) continue; - VPIteratorPair ChoiceRange = CandidatePairs.equal_range(*I); + std::vector<Value *> &JJ = CandidatePairs[*I]; - // The best pair to choose and its tree: + // The best pair to choose and its dag: size_t BestMaxDepth = 0; int BestEffSize = 0; - DenseSet<ValuePair> BestTree; - findBestTreeFor(CandidatePairs, CandidatePairCostSavings, + DenseSet<ValuePair> BestDAG; + findBestDAGFor(CandidatePairs, CandidatePairsSet, + CandidatePairCostSavings, PairableInsts, FixedOrderPairs, PairConnectionTypes, ConnectedPairs, ConnectedPairDeps, - PairableInstUsers, PairableInstUserMap, ChosenPairs, - BestTree, BestMaxDepth, BestEffSize, ChoiceRange, + PairableInstUsers, PairableInstUserMap, + PairableInstUserPairSet, ChosenPairs, + BestDAG, BestMaxDepth, BestEffSize, *I, JJ, UseCycleCheck); - // A tree has been chosen (or not) at this point. If no tree was + 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(if (BestTree.size() > 0) - dbgs() << "BBV: selected pairs in the best tree for: " - << *cast<Instruction>(*I) << "\n"); + DEBUG(dbgs() << "BBV: selected pairs in the best DAG for: " + << *cast<Instruction>(*I) << "\n"); - for (DenseSet<ValuePair>::iterator S = BestTree.begin(), - SE2 = BestTree.end(); S != SE2; ++S) { - // Insert the members of this tree into the list of chosen pairs. + 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 tree. - for (std::multimap<Value *, Value *>::iterator K = - CandidatePairs.begin(); K != CandidatePairs.end();) { - if (K->first == S->first || K->second == S->first || - K->second == S->second || K->first == S->second) { - // Don't remove the actual pair chosen so that it can be used - // in subsequent tree selections. - if (!(K->first == S->first && K->second == S->second)) - CandidatePairs.erase(K++); - else - ++K; - } else { - ++K; - } + // 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)); } } } @@ -2550,7 +2701,7 @@ namespace { continue; } else if (isa<CallInst>(I)) { Function *F = cast<CallInst>(I)->getCalledFunction(); - unsigned IID = F->getIntrinsicID(); + Intrinsic::ID IID = (Intrinsic::ID) F->getIntrinsicID(); if (o == NumOperands-1) { BasicBlock &BB = *I->getParent(); @@ -2559,8 +2710,7 @@ namespace { Type *ArgTypeJ = J->getType(); Type *VArgType = getVecTypeForPair(ArgTypeI, ArgTypeJ); - ReplacedOperands[o] = Intrinsic::getDeclaration(M, - (Intrinsic::ID) IID, VArgType); + 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 @@ -2647,7 +2797,7 @@ namespace { // Move all uses of the function I (including pairing-induced uses) after J. bool BBVectorize::canMoveUsesOfIAfterJ(BasicBlock &BB, - std::multimap<Value *, Value *> &LoadMoveSet, + DenseSet<ValuePair> &LoadMoveSetPairs, Instruction *I, Instruction *J) { // Skip to the first instruction past I. BasicBlock::iterator L = llvm::next(BasicBlock::iterator(I)); @@ -2655,18 +2805,18 @@ namespace { DenseSet<Value *> Users; AliasSetTracker WriteSet(*AA); for (; cast<Instruction>(L) != J; ++L) - (void) trackUsesOfI(Users, WriteSet, I, L, true, &LoadMoveSet); + (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, &LoadMoveSet); + 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, - std::multimap<Value *, Value *> &LoadMoveSet, + DenseSet<ValuePair> &LoadMoveSetPairs, Instruction *&InsertionPt, Instruction *I, Instruction *J) { // Skip to the first instruction past I. @@ -2675,7 +2825,7 @@ namespace { DenseSet<Value *> Users; AliasSetTracker WriteSet(*AA); for (; cast<Instruction>(L) != J;) { - if (trackUsesOfI(Users, WriteSet, I, L, true, &LoadMoveSet)) { + if (trackUsesOfI(Users, WriteSet, I, L, true, &LoadMoveSetPairs)) { // Move this instruction Instruction *InstToMove = L; ++L; @@ -2695,7 +2845,8 @@ namespace { // to be moved after J (the second instruction) when the pair is fused. void BBVectorize::collectPairLoadMoveSet(BasicBlock &BB, DenseMap<Value *, Value *> &ChosenPairs, - std::multimap<Value *, Value *> &LoadMoveSet, + 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)); @@ -2708,8 +2859,10 @@ namespace { // 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.insert(ValuePair(L, I)); + if (L->mayReadFromMemory()) { + LoadMoveSet[L].push_back(I); + LoadMoveSetPairs.insert(ValuePair(L, I)); + } } } } @@ -2718,20 +2871,22 @@ namespace { // 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 trees here as were found earlier, we'll + // 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, - std::multimap<Value *, Value *> &LoadMoveSet) { + 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, I); + collectPairLoadMoveSet(BB, ChosenPairs, LoadMoveSet, + LoadMoveSetPairs, I); } } @@ -2767,12 +2922,12 @@ namespace { // 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, - std::multimap<ValuePair, ValuePair> &ConnectedPairs, - std::multimap<ValuePair, ValuePair> &ConnectedPairDeps) { + 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 @@ -2786,8 +2941,10 @@ namespace { E = FlippedPairs.end(); P != E; ++P) ChosenPairs.insert(*P); - std::multimap<Value *, Value *> LoadMoveSet; - collectLoadMoveSet(BB, PairableInsts, ChosenPairs, LoadMoveSet); + DenseMap<Value *, std::vector<Value *> > LoadMoveSet; + DenseSet<ValuePair> LoadMoveSetPairs; + collectLoadMoveSet(BB, PairableInsts, ChosenPairs, + LoadMoveSet, LoadMoveSetPairs); DEBUG(dbgs() << "BBV: initial: \n" << BB << "\n"); @@ -2819,7 +2976,7 @@ namespace { ChosenPairs.erase(FP); ChosenPairs.erase(P); - if (!canMoveUsesOfIAfterJ(BB, LoadMoveSet, I, J)) { + if (!canMoveUsesOfIAfterJ(BB, LoadMoveSetPairs, I, J)) { DEBUG(dbgs() << "BBV: fusion of: " << *I << " <-> " << *J << " aborted because of non-trivial dependency cycle\n"); @@ -2836,18 +2993,20 @@ namespace { // of dependencies connected via swaps, and those directly connected, // and flip the order if the number of swaps is greater. bool OrigOrder = true; - VPPIteratorPair IP = ConnectedPairDeps.equal_range(ValuePair(I, J)); - if (IP.first == ConnectedPairDeps.end()) { - IP = ConnectedPairDeps.equal_range(ValuePair(J, I)); + 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 (IP.first != ConnectedPairDeps.end()) { + if (IJ != ConnectedPairDeps.end()) { unsigned NumDepsDirect = 0, NumDepsSwap = 0; - for (std::multimap<ValuePair, ValuePair>::iterator Q = IP.first; - Q != IP.second; ++Q) { + 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)); + PairConnectionTypes.find(VPPair(Q.second, Q.first)); assert(R != PairConnectionTypes.end() && "Cannot find pair connection type"); if (R->second == PairConnectionDirect) @@ -2873,17 +3032,20 @@ namespace { // If the pair being fused uses the opposite order from that in the pair // connection map, then we need to flip the types. - VPPIteratorPair IP = ConnectedPairs.equal_range(ValuePair(H, L)); - for (std::multimap<ValuePair, ValuePair>::iterator Q = IP.first; - Q != IP.second; ++Q) { - 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; - } + 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(); @@ -2915,12 +3077,12 @@ namespace { Instruction *K1 = 0, *K2 = 0; replaceOutputsOfPair(Context, L, H, K, InsertionPt, K1, K2); - // The use tree of the first original instruction must be moved to after - // the location of the second instruction. The entire use tree of the - // first instruction is disjoint from the input tree of the second + // 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, LoadMoveSet, InsertionPt, I, J); + moveUsesOfIAfterJ(BB, LoadMoveSetPairs, InsertionPt, I, J); if (!isa<StoreInst>(I)) { L->replaceAllUsesWith(K1); @@ -2937,17 +3099,23 @@ namespace { // yet-to-be-fused pair. The loads in question are the keys of the map. if (I->mayReadFromMemory()) { std::vector<ValuePair> NewSetMembers; - VPIteratorPair IPairRange = LoadMoveSet.equal_range(I); - VPIteratorPair JPairRange = LoadMoveSet.equal_range(J); - for (std::multimap<Value *, Value *>::iterator N = IPairRange.first; - N != IPairRange.second; ++N) - NewSetMembers.push_back(ValuePair(K, N->second)); - for (std::multimap<Value *, Value *>::iterator N = JPairRange.first; - N != JPairRange.second; ++N) - NewSetMembers.push_back(ValuePair(K, N->second)); + 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.insert(*A); + 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. @@ -2972,6 +3140,7 @@ 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) @@ -3006,6 +3175,7 @@ VectorizeConfig::VectorizeConfig() { MaxCandPairsForCycleCheck = ::MaxCandPairsForCycleCheck; SplatBreaksChain = ::SplatBreaksChain; MaxInsts = ::MaxInsts; + MaxPairs = ::MaxPairs; MaxIter = ::MaxIter; Pow2LenOnly = ::Pow2LenOnly; NoMemOpBoost = ::NoMemOpBoost; diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index feeececedb..07dd453424 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -6,7 +6,51 @@ // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// -#include "LoopVectorize.h" +// +// This is the LLVM loop vectorizer. This pass modifies 'vectorizable' loops +// and generates target-independent LLVM-IR. Legalization of the IR is done +// in the codegen. However, the vectorizer uses (will use) the codegen +// interfaces to generate IR that is likely to result in an optimal binary. +// +// The loop vectorizer combines consecutive loop iterations into a single +// 'wide' iteration. After this transformation the index is incremented +// by the SIMD vector width, and not by one. +// +// This pass has three parts: +// 1. The main loop pass that drives the different parts. +// 2. LoopVectorizationLegality - A unit that checks for the legality +// of the vectorization. +// 3. InnerLoopVectorizer - A unit that performs the actual +// widening of instructions. +// 4. LoopVectorizationCostModel - A unit that checks for the profitability +// of vectorization. It decides on the optimal vector width, which +// can be one, if vectorization is not profitable. +// +//===----------------------------------------------------------------------===// +// +// The reduction-variable vectorization is based on the paper: +// D. Nuzman and R. Henderson. Multi-platform Auto-vectorization. +// +// Variable uniformity checks are inspired by: +// Karrenberg, R. and Hack, S. Whole Function Vectorization. +// +// Other ideas/concepts are from: +// A. Zaks and D. Nuzman. Autovectorization in GCC-two years later. +// +// S. Maleki, Y. Gao, M. Garzaran, T. Wong and D. Padua. An Evaluation of +// Vectorizing Compilers. +// +//===----------------------------------------------------------------------===// + +#define LV_NAME "loop-vectorize" +#define DEBUG_TYPE LV_NAME + +#include "llvm/Transforms/Vectorize.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/MapVector.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallSet.h" +#include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/AliasSetTracker.h" @@ -14,46 +58,586 @@ #include "llvm/Analysis/LoopInfo.h" #include "llvm/Analysis/LoopIterator.h" #include "llvm/Analysis/LoopPass.h" -#include "llvm/Analysis/ScalarEvolutionExpander.h" +#include "llvm/Analysis/ScalarEvolution.h" #include "llvm/Analysis/ScalarEvolutionExpander.h" #include "llvm/Analysis/ScalarEvolutionExpressions.h" +#include "llvm/Analysis/TargetTransformInfo.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/Analysis/Verifier.h" -#include "llvm/Constants.h" -#include "llvm/DataLayout.h" -#include "llvm/DerivedTypes.h" -#include "llvm/Function.h" -#include "llvm/Instructions.h" -#include "llvm/IntrinsicInst.h" -#include "llvm/LLVMContext.h" -#include "llvm/Module.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Module.h" +#include "llvm/IR/Type.h" +#include "llvm/IR/Value.h" #include "llvm/Pass.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" #include "llvm/Support/raw_ostream.h" -#include "llvm/TargetTransformInfo.h" +#include "llvm/Target/TargetLibraryInfo.h" #include "llvm/Transforms/Scalar.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" #include "llvm/Transforms/Utils/Local.h" -#include "llvm/Transforms/Vectorize.h" -#include "llvm/Type.h" -#include "llvm/Value.h" +#include <algorithm> +#include <map> + +using namespace llvm; static cl::opt<unsigned> VectorizationFactor("force-vector-width", cl::init(0), cl::Hidden, cl::desc("Sets the SIMD width. Zero is autoselect.")); +static cl::opt<unsigned> +VectorizationUnroll("force-vector-unroll", cl::init(0), cl::Hidden, + cl::desc("Sets the vectorization unroll count. " + "Zero is autoselect.")); + static cl::opt<bool> EnableIfConversion("enable-if-conversion", cl::init(true), cl::Hidden, cl::desc("Enable if-conversion during vectorization.")); +/// We don't vectorize loops with a known constant trip count below this number. +static cl::opt<unsigned> +TinyTripCountVectorThreshold("vectorizer-min-trip-count", cl::init(16), + cl::Hidden, + cl::desc("Don't vectorize loops with a constant " + "trip count that is smaller than this " + "value.")); + +/// We don't unroll loops with a known constant trip count below this number. +static const unsigned TinyTripCountUnrollThreshold = 128; + +/// When performing a runtime memory check, do not check more than this +/// number of pointers. Notice that the check is quadratic! +static const unsigned RuntimeMemoryCheckThreshold = 4; + +/// We use a metadata with this name to indicate that a scalar loop was +/// vectorized and that we don't need to re-vectorize it if we run into it +/// again. +static const char* +AlreadyVectorizedMDName = "llvm.vectorizer.already_vectorized"; + namespace { +// Forward declarations. +class LoopVectorizationLegality; +class LoopVectorizationCostModel; + +/// InnerLoopVectorizer vectorizes loops which contain only one basic +/// block to a specified vectorization factor (VF). +/// This class performs the widening of scalars into vectors, or multiple +/// scalars. This class also implements the following features: +/// * It inserts an epilogue loop for handling loops that don't have iteration +/// counts that are known to be a multiple of the vectorization factor. +/// * It handles the code generation for reduction variables. +/// * Scalarization (implementation using scalars) of un-vectorizable +/// instructions. +/// InnerLoopVectorizer does not perform any vectorization-legality +/// checks, and relies on the caller to check for the different legality +/// aspects. The InnerLoopVectorizer relies on the +/// LoopVectorizationLegality class to provide information about the induction +/// and reduction variables that were found to a given vectorization factor. +class InnerLoopVectorizer { +public: + InnerLoopVectorizer(Loop *OrigLoop, ScalarEvolution *SE, LoopInfo *LI, + DominatorTree *DT, DataLayout *DL, + const TargetLibraryInfo *TLI, unsigned VecWidth, + unsigned UnrollFactor) + : OrigLoop(OrigLoop), SE(SE), LI(LI), DT(DT), DL(DL), TLI(TLI), + VF(VecWidth), UF(UnrollFactor), Builder(SE->getContext()), Induction(0), + OldInduction(0), WidenMap(UnrollFactor) {} + + // Perform the actual loop widening (vectorization). + void vectorize(LoopVectorizationLegality *Legal) { + // Create a new empty loop. Unlink the old loop and connect the new one. + createEmptyLoop(Legal); + // Widen each instruction in the old loop to a new one in the new loop. + // Use the Legality module to find the induction and reduction variables. + vectorizeLoop(Legal); + // Register the new loop and update the analysis passes. + updateAnalysis(); + } + +private: + /// A small list of PHINodes. + typedef SmallVector<PHINode*, 4> PhiVector; + /// When we unroll loops we have multiple vector values for each scalar. + /// This data structure holds the unrolled and vectorized values that + /// originated from one scalar instruction. + typedef SmallVector<Value*, 2> VectorParts; + + /// Add code that checks at runtime if the accessed arrays overlap. + /// Returns the comparator value or NULL if no check is needed. + Instruction *addRuntimeCheck(LoopVectorizationLegality *Legal, + Instruction *Loc); + /// Create an empty loop, based on the loop ranges of the old loop. + void createEmptyLoop(LoopVectorizationLegality *Legal); + /// Copy and widen the instructions from the old loop. + void vectorizeLoop(LoopVectorizationLegality *Legal); + + /// A helper function that computes the predicate of the block BB, assuming + /// that the header block of the loop is set to True. It returns the *entry* + /// mask for the block BB. + VectorParts createBlockInMask(BasicBlock *BB); + /// A helper function that computes the predicate of the edge between SRC + /// and DST. + VectorParts createEdgeMask(BasicBlock *Src, BasicBlock *Dst); + + /// A helper function to vectorize a single BB within the innermost loop. + void vectorizeBlockInLoop(LoopVectorizationLegality *Legal, BasicBlock *BB, + PhiVector *PV); + + /// Insert the new loop to the loop hierarchy and pass manager + /// and update the analysis passes. + void updateAnalysis(); + + /// This instruction is un-vectorizable. Implement it as a sequence + /// of scalars. + void scalarizeInstruction(Instruction *Instr); + + /// Vectorize Load and Store instructions, + void vectorizeMemoryInstruction(Instruction *Instr, + LoopVectorizationLegality *Legal); + + /// Create a broadcast instruction. This method generates a broadcast + /// instruction (shuffle) for loop invariant values and for the induction + /// value. If this is the induction variable then we extend it to N, N+1, ... + /// this is needed because each iteration in the loop corresponds to a SIMD + /// element. + Value *getBroadcastInstrs(Value *V); + + /// This function adds 0, 1, 2 ... to each vector element, starting at zero. + /// If Negate is set then negative numbers are added e.g. (0, -1, -2, ...). + /// The sequence starts at StartIndex. + Value *getConsecutiveVector(Value* Val, unsigned StartIdx, bool Negate); + + /// When we go over instructions in the basic block we rely on previous + /// values within the current basic block or on loop invariant values. + /// When we widen (vectorize) values we place them in the map. If the values + /// are not within the map, they have to be loop invariant, so we simply + /// broadcast them into a vector. + VectorParts &getVectorValue(Value *V); + + /// Generate a shuffle sequence that will reverse the vector Vec. + Value *reverseVector(Value *Vec); + + /// This is a helper class that holds the vectorizer state. It maps scalar + /// instructions to vector instructions. When the code is 'unrolled' then + /// then a single scalar value is mapped to multiple vector parts. The parts + /// are stored in the VectorPart type. + struct ValueMap { + /// C'tor. UnrollFactor controls the number of vectors ('parts') that + /// are mapped. + ValueMap(unsigned UnrollFactor) : UF(UnrollFactor) {} + + /// \return True if 'Key' is saved in the Value Map. + bool has(Value *Key) const { return MapStorage.count(Key); } + + /// Initializes a new entry in the map. Sets all of the vector parts to the + /// save value in 'Val'. + /// \return A reference to a vector with splat values. + VectorParts &splat(Value *Key, Value *Val) { + VectorParts &Entry = MapStorage[Key]; + Entry.assign(UF, Val); + return Entry; + } + + ///\return A reference to the value that is stored at 'Key'. + VectorParts &get(Value *Key) { + VectorParts &Entry = MapStorage[Key]; + if (Entry.empty()) + Entry.resize(UF); + assert(Entry.size() == UF); + return Entry; + } + + private: + /// The unroll factor. Each entry in the map stores this number of vector + /// elements. + unsigned UF; + + /// Map storage. We use std::map and not DenseMap because insertions to a + /// dense map invalidates its iterators. + std::map<Value *, VectorParts> MapStorage; + }; + + /// The original loop. + Loop *OrigLoop; + /// Scev analysis to use. + ScalarEvolution *SE; + /// Loop Info. + LoopInfo *LI; + /// Dominator Tree. + DominatorTree *DT; + /// Data Layout. + DataLayout *DL; + /// Target Library Info. + const TargetLibraryInfo *TLI; + + /// The vectorization SIMD factor to use. Each vector will have this many + /// vector elements. + unsigned VF; + /// The vectorization unroll factor to use. Each scalar is vectorized to this + /// many different vector instructions. + unsigned UF; + + /// The builder that we use + IRBuilder<> Builder; + + // --- Vectorization state --- + + /// The vector-loop preheader. + BasicBlock *LoopVectorPreHeader; + /// The scalar-loop preheader. + BasicBlock *LoopScalarPreHeader; + /// Middle Block between the vector and the scalar. + BasicBlock *LoopMiddleBlock; + ///The ExitBlock of the scalar loop. + BasicBlock *LoopExitBlock; + ///The vector loop body. + BasicBlock *LoopVectorBody; + ///The scalar loop body. + BasicBlock *LoopScalarBody; + /// A list of all bypass blocks. The first block is the entry of the loop. + SmallVector<BasicBlock *, 4> LoopBypassBlocks; + + /// The new Induction variable which was added to the new block. + PHINode *Induction; + /// The induction variable of the old basic block. + PHINode *OldInduction; + /// Maps scalars to widened vectors. + ValueMap WidenMap; +}; + +/// LoopVectorizationLegality checks if it is legal to vectorize a loop, and +/// to what vectorization factor. +/// This class does not look at the profitability of vectorization, only the +/// legality. This class has two main kinds of checks: +/// * Memory checks - The code in canVectorizeMemory checks if vectorization +/// will change the order of memory accesses in a way that will change the +/// correctness of the program. +/// * Scalars checks - The code in canVectorizeInstrs and canVectorizeMemory +/// checks for a number of different conditions, such as the availability of a +/// single induction variable, that all types are supported and vectorize-able, +/// etc. This code reflects the capabilities of InnerLoopVectorizer. +/// This class is also used by InnerLoopVectorizer for identifying +/// induction variable and the different reduction variables. +class LoopVectorizationLegality { +public: + LoopVectorizationLegality(Loop *L, ScalarEvolution *SE, DataLayout *DL, + DominatorTree *DT, TargetTransformInfo* TTI, + AliasAnalysis *AA, TargetLibraryInfo *TLI) + : TheLoop(L), SE(SE), DL(DL), DT(DT), TTI(TTI), AA(AA), TLI(TLI), + Induction(0) {} + + /// This enum represents the kinds of reductions that we support. + enum ReductionKind { + RK_NoReduction, ///< Not a reduction. + RK_IntegerAdd, ///< Sum of integers. + RK_IntegerMult, ///< Product of integers. + RK_IntegerOr, ///< Bitwise or logical OR of numbers. + RK_IntegerAnd, ///< Bitwise or logical AND of numbers. + RK_IntegerXor, ///< Bitwise or logical XOR of numbers. + RK_FloatAdd, ///< Sum of floats. + RK_FloatMult ///< Product of floats. + }; + + /// This enum represents the kinds of inductions that we support. + enum InductionKind { + IK_NoInduction, ///< Not an induction variable. + IK_IntInduction, ///< Integer induction variable. Step = 1. + IK_ReverseIntInduction, ///< Reverse int induction variable. Step = -1. + IK_PtrInduction, ///< Pointer induction var. Step = sizeof(elem). + IK_ReversePtrInduction ///< Reverse ptr indvar. Step = - sizeof(elem). + }; + + /// This POD struct holds information about reduction variables. + struct ReductionDescriptor { + ReductionDescriptor() : StartValue(0), LoopExitInstr(0), + Kind(RK_NoReduction) {} + + ReductionDescriptor(Value *Start, Instruction *Exit, ReductionKind K) + : StartValue(Start), LoopExitInstr(Exit), Kind(K) {} + + // The starting value of the reduction. + // It does not have to be zero! + Value *StartValue; + // The instruction who's value is used outside the loop. + Instruction *LoopExitInstr; + // The kind of the reduction. + ReductionKind Kind; + }; + + // This POD struct holds information about the memory runtime legality + // check that a group of pointers do not overlap. + struct RuntimePointerCheck { + RuntimePointerCheck() : Need(false) {} + + /// Reset the state of the pointer runtime information. + void reset() { + Need = false; + Pointers.clear(); + Starts.clear(); + Ends.clear(); + } + + /// Insert a pointer and calculate the start and end SCEVs. + void insert(ScalarEvolution *SE, Loop *Lp, Value *Ptr); + + /// This flag indicates if we need to add the runtime check. + bool Need; + /// Holds the pointers that we need to check. + SmallVector<Value*, 2> Pointers; + /// Holds the pointer value at the beginning of the loop. + SmallVector<const SCEV*, 2> Starts; + /// Holds the pointer value at the end of the loop. + SmallVector<const SCEV*, 2> Ends; + }; + + /// A POD for saving information about induction variables. + struct InductionInfo { + InductionInfo(Value *Start, InductionKind K) : StartValue(Start), IK(K) {} + InductionInfo() : StartValue(0), IK(IK_NoInduction) {} + /// Start value. + Value *StartValue; + /// Induction kind. + InductionKind IK; + }; + + /// ReductionList contains the reduction descriptors for all + /// of the reductions that were found in the loop. + typedef DenseMap<PHINode*, ReductionDescriptor> ReductionList; + + /// InductionList saves induction variables and maps them to the + /// induction descriptor. + typedef MapVector<PHINode*, InductionInfo> InductionList; + + /// Alias(Multi)Map stores the values (GEPs or underlying objects and their + /// respective Store/Load instruction(s) to calculate aliasing. + typedef MapVector<Value*, Instruction* > AliasMap; + typedef DenseMap<Value*, std::vector<Instruction*> > AliasMultiMap; + + /// Returns true if it is legal to vectorize this loop. + /// This does not mean that it is profitable to vectorize this + /// loop, only that it is legal to do so. + bool canVectorize(); + + /// Returns the Induction variable. + PHINode *getInduction() { return Induction; } + + /// Returns the reduction variables found in the loop. + ReductionList *getReductionVars() { return &Reductions; } + + /// Returns the induction variables found in the loop. + InductionList *getInductionVars() { return &Inductions; } + + /// Returns True if V is an induction variable in this loop. + bool isInductionVariable(const Value *V); + + /// Return true if the block BB needs to be predicated in order for the loop + /// to be vectorized. + bool blockNeedsPredication(BasicBlock *BB); + + /// Check if this pointer is consecutive when vectorizing. This happens + /// when the last index of the GEP is the induction variable, or that the + /// pointer itself is an induction variable. + /// This check allows us to vectorize A[idx] into a wide load/store. + /// Returns: + /// 0 - Stride is unknown or non consecutive. + /// 1 - Address is consecutive. + /// -1 - Address is consecutive, and decreasing. + int isConsecutivePtr(Value *Ptr); + + /// Returns true if the value V is uniform within the loop. + bool isUniform(Value *V); + + /// Returns true if this instruction will remain scalar after vectorization. + bool isUniformAfterVectorization(Instruction* I) { return Uniforms.count(I); } + + /// Returns the information that we collected about runtime memory check. + RuntimePointerCheck *getRuntimePointerCheck() { return &PtrRtCheck; } +private: + /// Check if a single basic block loop is vectorizable. + /// At this point we know that this is a loop with a constant trip count + /// and we only need to check individual instructions. + bool canVectorizeInstrs(); + + /// When we vectorize loops we may change the order in which + /// we read and write from memory. This method checks if it is + /// legal to vectorize the code, considering only memory constrains. + /// Returns true if the loop is vectorizable + bool canVectorizeMemory(); + + /// Return true if we can vectorize this loop using the IF-conversion + /// transformation. + bool canVectorizeWithIfConvert(); + + /// Collect the variables that need to stay uniform after vectorization. + void collectLoopUniforms(); + + /// Return true if all of the instructions in the block can be speculatively + /// executed. + bool blockCanBePredicated(BasicBlock *BB); + + /// Returns True, if 'Phi' is the kind of reduction variable for type + /// 'Kind'. If this is a reduction variable, it adds it to ReductionList. + bool AddReductionVar(PHINode *Phi, ReductionKind Kind); + /// Returns true if the instruction I can be a reduction variable of type + /// 'Kind'. + bool isReductionInstr(Instruction *I, ReductionKind Kind); + /// Returns the induction kind of Phi. This function may return NoInduction + /// if the PHI is not an induction variable. + InductionKind isInductionVariable(PHINode *Phi); + /// Return true if can compute the address bounds of Ptr within the loop. + bool hasComputableBounds(Value *Ptr); + /// Return true if there is the chance of write reorder. + bool hasPossibleGlobalWriteReorder(Value *Object, + Instruction *Inst, + AliasMultiMap &WriteObjects, + unsigned MaxByteWidth); + /// Return the AA location for a load or a store. + AliasAnalysis::Location getLoadStoreLocation(Instruction *Inst); + + + /// The loop that we evaluate. + Loop *TheLoop; + /// Scev analysis. + ScalarEvolution *SE; + /// DataLayout analysis. + DataLayout *DL; + /// Dominators. + DominatorTree *DT; + /// Target Info. + TargetTransformInfo *TTI; + /// Alias Analysis. + AliasAnalysis *AA; + /// Target Library Info. + TargetLibraryInfo *TLI; + + // --- vectorization state --- // + + /// Holds the integer induction variable. This is the counter of the + /// loop. + PHINode *Induction; + /// Holds the reduction variables. + ReductionList Reductions; + /// Holds all of the induction variables that we found in the loop. + /// Notice that inductions don't need to start at zero and that induction + /// variables can be pointers. + InductionList Inductions; + + /// Allowed outside users. This holds the reduction + /// vars which can be accessed from outside the loop. + SmallPtrSet<Value*, 4> AllowedExit; + /// This set holds the variables which are known to be uniform after + /// vectorization. + SmallPtrSet<Instruction*, 4> Uniforms; + /// We need to check that all of the pointers in this list are disjoint + /// at runtime. + RuntimePointerCheck PtrRtCheck; +}; + +/// LoopVectorizationCostModel - estimates the expected speedups due to +/// vectorization. +/// In many cases vectorization is not profitable. This can happen because of +/// a number of reasons. In this class we mainly attempt to predict the +/// expected speedup/slowdowns due to the supported instruction set. We use the +/// TargetTransformInfo to query the different backends for the cost of +/// different operations. +class LoopVectorizationCostModel { +public: + LoopVectorizationCostModel(Loop *L, ScalarEvolution *SE, LoopInfo *LI, + LoopVectorizationLegality *Legal, + const TargetTransformInfo &TTI, + DataLayout *DL, const TargetLibraryInfo *TLI) + : TheLoop(L), SE(SE), LI(LI), Legal(Legal), TTI(TTI), DL(DL), TLI(TLI) {} + + /// Information about vectorization costs + struct VectorizationFactor { + unsigned Width; // Vector width with best cost + unsigned Cost; // Cost of the loop with that width + }; + /// \return The most profitable vectorization factor and the cost of that VF. + /// This method checks every power of two up to VF. If UserVF is not ZERO + /// then this vectorization factor will be selected if vectorization is + /// possible. + VectorizationFactor selectVectorizationFactor(bool OptForSize, + unsigned UserVF); + + /// \return The size (in bits) of the widest type in the code that + /// needs to be vectorized. We ignore values that remain scalar such as + /// 64 bit loop indices. + unsigned getWidestType(); + + /// \return The most profitable unroll factor. + /// If UserUF is non-zero then this method finds the best unroll-factor + /// based on register pressure and other parameters. + /// VF and LoopCost are the selected vectorization factor and the cost of the + /// selected VF. + unsigned selectUnrollFactor(bool OptForSize, unsigned UserUF, unsigned VF, + unsigned LoopCost); + + /// \brief A struct that represents some properties of the register usage + /// of a loop. + struct RegisterUsage { + /// Holds the number of loop invariant values that are used in the loop. + unsigned LoopInvariantRegs; + /// Holds the maximum number of concurrent live intervals in the loop. + unsigned MaxLocalUsers; + /// Holds the number of instructions in the loop. + unsigned NumInstructions; + }; + + /// \return information about the register usage of the loop. + RegisterUsage calculateRegisterUsage(); + +private: + /// Returns the expected execution cost. The unit of the cost does + /// not matter because we use the 'cost' units to compare different + /// vector widths. The cost that is returned is *not* normalized by + /// the factor width. + unsigned expectedCost(unsigned VF); + + /// Returns the execution time cost of an instruction for a given vector + /// width. Vector width of one means scalar. + unsigned getInstructionCost(Instruction *I, unsigned VF); + + /// A helper function for converting Scalar types to vector types. + /// If the incoming type is void, we return void. If the VF is 1, we return + /// the scalar type. + static Type* ToVectorTy(Type *Scalar, unsigned VF); + + /// Returns whether the instruction is a load or store and will be a emitted + /// as a vector operation. + bool isConsecutiveLoadOrStore(Instruction *I); + + /// The loop that we evaluate. + Loop *TheLoop; + /// Scev analysis. + ScalarEvolution *SE; + /// Loop Info analysis. + LoopInfo *LI; + /// Vectorization legality. + LoopVectorizationLegality *Legal; + /// Vector target information. + const TargetTransformInfo &TTI; + /// Target data layout information. + DataLayout *DL; + /// Target Library Info. + const TargetLibraryInfo *TLI; +}; + /// The LoopVectorize Pass. struct LoopVectorize : public LoopPass { - static char ID; // Pass identification, replacement for typeid + /// Pass identification, replacement for typeid + static char ID; - LoopVectorize() : LoopPass(ID) { + explicit LoopVectorize() : LoopPass(ID) { initializeLoopVectorizePass(*PassRegistry::getPassRegistry()); } @@ -62,6 +646,8 @@ struct LoopVectorize : public LoopPass { LoopInfo *LI; TargetTransformInfo *TTI; DominatorTree *DT; + AliasAnalysis *AA; + TargetLibraryInfo *TLI; virtual bool runOnLoop(Loop *L, LPPassManager &LPM) { // We only vectorize innermost loops. @@ -71,45 +657,57 @@ struct LoopVectorize : public LoopPass { SE = &getAnalysis<ScalarEvolution>(); DL = getAnalysisIfAvailable<DataLayout>(); LI = &getAnalysis<LoopInfo>(); - TTI = getAnalysisIfAvailable<TargetTransformInfo>(); + TTI = &getAnalysis<TargetTransformInfo>(); DT = &getAnalysis<DominatorTree>(); + AA = getAnalysisIfAvailable<AliasAnalysis>(); + TLI = getAnalysisIfAvailable<TargetLibraryInfo>(); DEBUG(dbgs() << "LV: Checking a loop in \"" << L->getHeader()->getParent()->getName() << "\"\n"); // Check if it is legal to vectorize the loop. - LoopVectorizationLegality LVL(L, SE, DL, DT); + LoopVectorizationLegality LVL(L, SE, DL, DT, TTI, AA, TLI); if (!LVL.canVectorize()) { DEBUG(dbgs() << "LV: Not vectorizing.\n"); return false; } - // Select the preffered vectorization factor. - unsigned VF = 1; - if (VectorizationFactor == 0) { - const VectorTargetTransformInfo *VTTI = 0; - if (TTI) - VTTI = TTI->getVectorTargetTransformInfo(); - // Use the cost model. - LoopVectorizationCostModel CM(L, SE, &LVL, VTTI); - VF = CM.findBestVectorizationFactor(); - - if (VF == 1) { - DEBUG(dbgs() << "LV: Vectorization is possible but not beneficial.\n"); - return false; - } + // Use the cost model. + LoopVectorizationCostModel CM(L, SE, LI, &LVL, *TTI, DL, TLI); + + // Check the function attributes to find out if this function should be + // optimized for size. + Function *F = L->getHeader()->getParent(); + Attribute::AttrKind SzAttr = Attribute::OptimizeForSize; + Attribute::AttrKind FlAttr = Attribute::NoImplicitFloat; + unsigned FnIndex = AttributeSet::FunctionIndex; + bool OptForSize = F->getAttributes().hasAttribute(FnIndex, SzAttr); + bool NoFloat = F->getAttributes().hasAttribute(FnIndex, FlAttr); + + if (NoFloat) { + DEBUG(dbgs() << "LV: Can't vectorize when the NoImplicitFloat" + "attribute is used.\n"); + return false; + } - } else { - // Use the user command flag. - VF = VectorizationFactor; + // Select the optimal vectorization factor. + LoopVectorizationCostModel::VectorizationFactor VF; + VF = CM.selectVectorizationFactor(OptForSize, VectorizationFactor); + // Select the unroll factor. + unsigned UF = CM.selectUnrollFactor(OptForSize, VectorizationUnroll, + VF.Width, VF.Cost); + + if (VF.Width == 1) { + DEBUG(dbgs() << "LV: Vectorization is possible but not beneficial.\n"); + return false; } - DEBUG(dbgs() << "LV: Found a vectorizable loop ("<< VF << ") in "<< - L->getHeader()->getParent()->getParent()->getModuleIdentifier()<< - "\n"); + DEBUG(dbgs() << "LV: Found a vectorizable loop ("<< VF.Width << ") in "<< + F->getParent()->getModuleIdentifier()<<"\n"); + DEBUG(dbgs() << "LV: Unroll Factor is " << UF << "\n"); - // If we decided that it is *legal* to vectorizer the loop then do it. - InnerLoopVectorizer LB(L, SE, LI, DT, DL, VF); + // If we decided that it is *legal* to vectorize the loop then do it. + InnerLoopVectorizer LB(L, SE, LI, DT, DL, TLI, VF.Width, UF); LB.vectorize(&LVL); DEBUG(verifyFunction(*L->getHeader()->getParent())); @@ -120,16 +718,17 @@ struct LoopVectorize : public LoopPass { LoopPass::getAnalysisUsage(AU); AU.addRequiredID(LoopSimplifyID); AU.addRequiredID(LCSSAID); + AU.addRequired<DominatorTree>(); AU.addRequired<LoopInfo>(); AU.addRequired<ScalarEvolution>(); - AU.addRequired<DominatorTree>(); + AU.addRequired<TargetTransformInfo>(); AU.addPreserved<LoopInfo>(); AU.addPreserved<DominatorTree>(); } }; -}// namespace +} // end anonymous namespace //===----------------------------------------------------------------------===// // Implementation of LoopVectorizationLegality, InnerLoopVectorizer and @@ -150,11 +749,6 @@ LoopVectorizationLegality::RuntimePointerCheck::insert(ScalarEvolution *SE, } Value *InnerLoopVectorizer::getBroadcastInstrs(Value *V) { - // Create the types. - LLVMContext &C = V->getContext(); - Type *VTy = VectorType::get(V->getType(), VF); - Type *I32 = IntegerType::getInt32Ty(C); - // Save the current insertion location. Instruction *Loc = Builder.GetInsertPoint(); @@ -167,14 +761,8 @@ Value *InnerLoopVectorizer::getBroadcastInstrs(Value *V) { if (Invariant) Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator()); - Constant *Zero = ConstantInt::get(I32, 0); - Value *Zeros = ConstantAggregateZero::get(VectorType::get(I32, VF)); - Value *UndefVal = UndefValue::get(VTy); - // Insert the value into a new vector. - Value *SingleElem = Builder.CreateInsertElement(UndefVal, V, Zero); // Broadcast the scalar into all locations in the vector. - Value *Shuf = Builder.CreateShuffleVector(SingleElem, UndefVal, Zeros, - "broadcast"); + Value *Shuf = Builder.CreateVectorSplat(VF, V, "broadcast"); // Restore the builder insertion point. if (Invariant) @@ -183,7 +771,8 @@ Value *InnerLoopVectorizer::getBroadcastInstrs(Value *V) { return Shuf; } -Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, bool Negate) { +Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, unsigned StartIdx, + bool Negate) { assert(Val->getType()->isVectorTy() && "Must be a vector"); assert(Val->getType()->getScalarType()->isIntegerTy() && "Elem must be an integer"); @@ -194,8 +783,10 @@ Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, bool Negate) { SmallVector<Constant*, 8> Indices; // Create a vector of consecutive numbers from zero to VF. - for (int i = 0; i < VLen; ++i) - Indices.push_back(ConstantInt::get(ITy, Negate ? (-i): i )); + for (int i = 0; i < VLen; ++i) { + int Idx = Negate ? (-i): i; + Indices.push_back(ConstantInt::get(ITy, StartIdx + Idx)); + } // Add the consecutive indices to the vector value. Constant *Cv = ConstantVector::get(Indices); @@ -203,28 +794,56 @@ Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, bool Negate) { return Builder.CreateAdd(Val, Cv, "induction"); } -bool LoopVectorizationLegality::isConsecutivePtr(Value *Ptr) { +int LoopVectorizationLegality::isConsecutivePtr(Value *Ptr) { assert(Ptr->getType()->isPointerTy() && "Unexpected non ptr"); + // Make sure that the pointer does not point to structs. + if (cast<PointerType>(Ptr->getType())->getElementType()->isAggregateType()) + return 0; // If this value is a pointer induction variable we know it is consecutive. PHINode *Phi = dyn_cast_or_null<PHINode>(Ptr); if (Phi && Inductions.count(Phi)) { InductionInfo II = Inductions[Phi]; - if (PtrInduction == II.IK) - return true; + if (IK_PtrInduction == II.IK) + return 1; + else if (IK_ReversePtrInduction == II.IK) + return -1; } GetElementPtrInst *Gep = dyn_cast_or_null<GetElementPtrInst>(Ptr); if (!Gep) - return false; + return 0; unsigned NumOperands = Gep->getNumOperands(); Value *LastIndex = Gep->getOperand(NumOperands - 1); + Value *GpPtr = Gep->getPointerOperand(); + // If this GEP value is a consecutive pointer induction variable and all of + // the indices are constant then we know it is consecutive. We can + Phi = dyn_cast<PHINode>(GpPtr); + if (Phi && Inductions.count(Phi)) { + + // Make sure that the pointer does not point to structs. + PointerType *GepPtrType = cast<PointerType>(GpPtr->getType()); + if (GepPtrType->getElementType()->isAggregateType()) + return 0; + + // Make sure that all of the index operands are loop invariant. + for (unsigned i = 1; i < NumOperands; ++i) + if (!SE->isLoopInvariant(SE->getSCEV(Gep->getOperand(i)), TheLoop)) + return 0; + + InductionInfo II = Inductions[Phi]; + if (IK_PtrInduction == II.IK) + return 1; + else if (IK_ReversePtrInduction == II.IK) + return -1; + } + // Check that all of the gep indices are uniform except for the last. for (unsigned i = 0; i < NumOperands - 1; ++i) if (!SE->isLoopInvariant(SE->getSCEV(Gep->getOperand(i)), TheLoop)) - return false; + return 0; // We can emit wide load/stores only if the last index is the induction // variable. @@ -235,39 +854,153 @@ bool LoopVectorizationLegality::isConsecutivePtr(Value *Ptr) { // The memory is consecutive because the last index is consecutive // and all other indices are loop invariant. if (Step->isOne()) - return true; + return 1; + if (Step->isAllOnesValue()) + return -1; } - return false; + return 0; } bool LoopVectorizationLegality::isUniform(Value *V) { return (SE->isLoopInvariant(SE->getSCEV(V), TheLoop)); } -Value *InnerLoopVectorizer::getVectorValue(Value *V) { +InnerLoopVectorizer::VectorParts& +InnerLoopVectorizer::getVectorValue(Value *V) { assert(V != Induction && "The new induction variable should not be used."); assert(!V->getType()->isVectorTy() && "Can't widen a vector"); - // If we saved a vectorized copy of V, use it. - Value *&MapEntry = WidenMap[V]; - if (MapEntry) - return MapEntry; - // Broadcast V and save the value for future uses. + // If we have this scalar in the map, return it. + if (WidenMap.has(V)) + return WidenMap.get(V); + + // If this scalar is unknown, assume that it is a constant or that it is + // loop invariant. Broadcast V and save the value for future uses. Value *B = getBroadcastInstrs(V); - MapEntry = B; - return B; + return WidenMap.splat(V, B); } -Constant* -InnerLoopVectorizer::getUniformVector(unsigned Val, Type* ScalarTy) { - return ConstantVector::getSplat(VF, ConstantInt::get(ScalarTy, Val, true)); +Value *InnerLoopVectorizer::reverseVector(Value *Vec) { + assert(Vec->getType()->isVectorTy() && "Invalid type"); + SmallVector<Constant*, 8> ShuffleMask; + for (unsigned i = 0; i < VF; ++i) + ShuffleMask.push_back(Builder.getInt32(VF - i - 1)); + + return Builder.CreateShuffleVector(Vec, UndefValue::get(Vec->getType()), + ConstantVector::get(ShuffleMask), + "reverse"); +} + + +void InnerLoopVectorizer::vectorizeMemoryInstruction(Instruction *Instr, + LoopVectorizationLegality *Legal) { + // Attempt to issue a wide load. + LoadInst *LI = dyn_cast<LoadInst>(Instr); + StoreInst *SI = dyn_cast<StoreInst>(Instr); + + assert((LI || SI) && "Invalid Load/Store instruction"); + + Type *ScalarDataTy = LI ? LI->getType() : SI->getValueOperand()->getType(); + Type *DataTy = VectorType::get(ScalarDataTy, VF); + Value *Ptr = LI ? LI->getPointerOperand() : SI->getPointerOperand(); + unsigned Alignment = LI ? LI->getAlignment() : SI->getAlignment(); + + // If the pointer is loop invariant or if it is non consecutive, + // scalarize the load. + int Stride = Legal->isConsecutivePtr(Ptr); + bool Reverse = Stride < 0; + bool UniformLoad = LI && Legal->isUniform(Ptr); + if (Stride == 0 || UniformLoad) + return scalarizeInstruction(Instr); + + Constant *Zero = Builder.getInt32(0); + VectorParts &Entry = WidenMap.get(Instr); + + // Handle consecutive loads/stores. + GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr); + if (Gep && Legal->isInductionVariable(Gep->getPointerOperand())) { + Value *PtrOperand = Gep->getPointerOperand(); + Value *FirstBasePtr = getVectorValue(PtrOperand)[0]; + FirstBasePtr = Builder.CreateExtractElement(FirstBasePtr, Zero); + + // Create the new GEP with the new induction variable. + GetElementPtrInst *Gep2 = cast<GetElementPtrInst>(Gep->clone()); + Gep2->setOperand(0, FirstBasePtr); + Gep2->setName("gep.indvar.base"); + Ptr = Builder.Insert(Gep2); + } else if (Gep) { + assert(SE->isLoopInvariant(SE->getSCEV(Gep->getPointerOperand()), + OrigLoop) && "Base ptr must be invariant"); + + // The last index does not have to be the induction. It can be + // consecutive and be a function of the index. For example A[I+1]; + unsigned NumOperands = Gep->getNumOperands(); + + Value *LastGepOperand = Gep->getOperand(NumOperands - 1); + VectorParts &GEPParts = getVectorValue(LastGepOperand); + Value *LastIndex = GEPParts[0]; + LastIndex = Builder.CreateExtractElement(LastIndex, Zero); + + // Create the new GEP with the new induction variable. + GetElementPtrInst *Gep2 = cast<GetElementPtrInst>(Gep->clone()); + Gep2->setOperand(NumOperands - 1, LastIndex); + Gep2->setName("gep.indvar.idx"); + Ptr = Builder.Insert(Gep2); + } else { + // Use the induction element ptr. + assert(isa<PHINode>(Ptr) && "Invalid induction ptr"); + VectorParts &PtrVal = getVectorValue(Ptr); + Ptr = Builder.CreateExtractElement(PtrVal[0], Zero); + } + + // Handle Stores: + if (SI) { + assert(!Legal->isUniform(SI->getPointerOperand()) && + "We do not allow storing to uniform addresses"); + + VectorParts &StoredVal = getVectorValue(SI->getValueOperand()); + for (unsigned Part = 0; Part < UF; ++Part) { + // Calculate the pointer for the specific unroll-part. + Value *PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(Part * VF)); + + if (Reverse) { + // If we store to reverse consecutive memory locations then we need + // to reverse the order of elements in the stored value. + StoredVal[Part] = reverseVector(StoredVal[Part]); + // If the address is consecutive but reversed, then the + // wide store needs to start at the last vector element. + PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(-Part * VF)); + PartPtr = Builder.CreateGEP(PartPtr, Builder.getInt32(1 - VF)); + } + + Value *VecPtr = Builder.CreateBitCast(PartPtr, DataTy->getPointerTo()); + Builder.CreateStore(StoredVal[Part], VecPtr)->setAlignment(Alignment); + } + } + + for (unsigned Part = 0; Part < UF; ++Part) { + // Calculate the pointer for the specific unroll-part. + Value *PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(Part * VF)); + + if (Reverse) { + // If the address is consecutive but reversed, then the + // wide store needs to start at the last vector element. + PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(-Part * VF)); + PartPtr = Builder.CreateGEP(PartPtr, Builder.getInt32(1 - VF)); + } + + Value *VecPtr = Builder.CreateBitCast(PartPtr, DataTy->getPointerTo()); + Value *LI = Builder.CreateLoad(VecPtr, "wide.load"); + cast<LoadInst>(LI)->setAlignment(Alignment); + Entry[Part] = Reverse ? reverseVector(LI) : LI; + } } void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr) { assert(!Instr->getType()->isAggregateType() && "Can't handle vectors"); // Holds vector parameters or scalars, in case of uniform vals. - SmallVector<Value*, 8> Params; + SmallVector<VectorParts, 4> Params; // Find all of the vectorized parameters. for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { @@ -284,13 +1017,15 @@ void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr) { // If the src is an instruction that appeared earlier in the basic block // then it should already be vectorized. - if (SrcInst && SrcInst->getParent() == Instr->getParent()) { - assert(WidenMap.count(SrcInst) && "Source operand is unavailable"); + if (SrcInst && OrigLoop->contains(SrcInst)) { + assert(WidenMap.has(SrcInst) && "Source operand is unavailable"); // The parameter is a vector value from earlier. - Params.push_back(WidenMap[SrcInst]); + Params.push_back(WidenMap.get(SrcInst)); } else { // The parameter is a scalar from outside the loop. Maybe even a constant. - Params.push_back(SrcOp); + VectorParts Scalars; + Scalars.append(UF, SrcOp); + Params.push_back(Scalars); } } @@ -299,42 +1034,41 @@ void InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr) { // Does this instruction return a value ? bool IsVoidRetTy = Instr->getType()->isVoidTy(); - Value *VecResults = 0; - // If we have a return value, create an empty vector. We place the scalarized - // instructions in this vector. - if (!IsVoidRetTy) - VecResults = UndefValue::get(VectorType::get(Instr->getType(), VF)); + Value *UndefVec = IsVoidRetTy ? 0 : + UndefValue::get(VectorType::get(Instr->getType(), VF)); + // Create a new entry in the WidenMap and initialize it to Undef or Null. + VectorParts &VecResults = WidenMap.splat(Instr, UndefVec); // For each scalar that we create: - for (unsigned i = 0; i < VF; ++i) { - Instruction *Cloned = Instr->clone(); - if (!IsVoidRetTy) - Cloned->setName(Instr->getName() + ".cloned"); - // Replace the operands of the cloned instrucions with extracted scalars. - for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { - Value *Op = Params[op]; - // Param is a vector. Need to extract the right lane. - if (Op->getType()->isVectorTy()) - Op = Builder.CreateExtractElement(Op, Builder.getInt32(i)); - Cloned->setOperand(op, Op); - } + for (unsigned Width = 0; Width < VF; ++Width) { + // For each vector unroll 'part': + for (unsigned Part = 0; Part < UF; ++Part) { + Instruction *Cloned = Instr->clone(); + if (!IsVoidRetTy) + Cloned->setName(Instr->getName() + ".cloned"); + // Replace the operands of the cloned instrucions with extracted scalars. + for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { + Value *Op = Params[op][Part]; + // Param is a vector. Need to extract the right lane. + if (Op->getType()->isVectorTy()) + Op = Builder.CreateExtractElement(Op, Builder.getInt32(Width)); + Cloned->setOperand(op, Op); + } - // Place the cloned scalar in the new loop. - Builder.Insert(Cloned); + // Place the cloned scalar in the new loop. + Builder.Insert(Cloned); - // If the original scalar returns a value we need to place it in a vector - // so that future users will be able to use it. - if (!IsVoidRetTy) - VecResults = Builder.CreateInsertElement(VecResults, Cloned, - Builder.getInt32(i)); + // If the original scalar returns a value we need to place it in a vector + // so that future users will be able to use it. + if (!IsVoidRetTy) + VecResults[Part] = Builder.CreateInsertElement(VecResults[Part], Cloned, + Builder.getInt32(Width)); + } } - - if (!IsVoidRetTy) - WidenMap[Instr] = VecResults; } -Value* +Instruction * InnerLoopVectorizer::addRuntimeCheck(LoopVectorizationLegality *Legal, Instruction *Loc) { LoopVectorizationLegality::RuntimePointerCheck *PtrRtCheck = @@ -343,7 +1077,7 @@ InnerLoopVectorizer::addRuntimeCheck(LoopVectorizationLegality *Legal, if (!PtrRtCheck->Need) return NULL; - Value *MemoryRuntimeCheck = 0; + Instruction *MemoryRuntimeCheck = 0; unsigned NumPointers = PtrRtCheck->Pointers.size(); SmallVector<Value* , 2> Starts; SmallVector<Value* , 2> Ends; @@ -372,28 +1106,23 @@ InnerLoopVectorizer::addRuntimeCheck(LoopVectorizationLegality *Legal, } } + IRBuilder<> ChkBuilder(Loc); + for (unsigned i = 0; i < NumPointers; ++i) { for (unsigned j = i+1; j < NumPointers; ++j) { - Instruction::CastOps Op = Instruction::BitCast; - Value *Start0 = CastInst::Create(Op, Starts[i], PtrArithTy, "bc", Loc); - Value *Start1 = CastInst::Create(Op, Starts[j], PtrArithTy, "bc", Loc); - Value *End0 = CastInst::Create(Op, Ends[i], PtrArithTy, "bc", Loc); - Value *End1 = CastInst::Create(Op, Ends[j], PtrArithTy, "bc", Loc); - - Value *Cmp0 = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULE, - Start0, End1, "bound0", Loc); - Value *Cmp1 = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULE, - Start1, End0, "bound1", Loc); - Value *IsConflict = BinaryOperator::Create(Instruction::And, Cmp0, Cmp1, - "found.conflict", Loc); + Value *Start0 = ChkBuilder.CreateBitCast(Starts[i], PtrArithTy, "bc"); + Value *Start1 = ChkBuilder.CreateBitCast(Starts[j], PtrArithTy, "bc"); + Value *End0 = ChkBuilder.CreateBitCast(Ends[i], PtrArithTy, "bc"); + Value *End1 = ChkBuilder.CreateBitCast(Ends[j], PtrArithTy, "bc"); + + Value *Cmp0 = ChkBuilder.CreateICmpULE(Start0, End1, "bound0"); + Value *Cmp1 = ChkBuilder.CreateICmpULE(Start1, End0, "bound1"); + Value *IsConflict = ChkBuilder.CreateAnd(Cmp0, Cmp1, "found.conflict"); if (MemoryRuntimeCheck) - MemoryRuntimeCheck = BinaryOperator::Create(Instruction::Or, - MemoryRuntimeCheck, - IsConflict, - "conflict.rdx", Loc); - else - MemoryRuntimeCheck = IsConflict; + IsConflict = ChkBuilder.CreateOr(MemoryRuntimeCheck, IsConflict, + "conflict.rdx"); + MemoryRuntimeCheck = cast<Instruction>(IsConflict); } } @@ -407,27 +1136,27 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { the vectorized instructions while the old loop will continue to run the scalar remainder. - [ ] <-- vector loop bypass. - / | - / v + [ ] <-- vector loop bypass (may consist of multiple blocks). + / | + / v | [ ] <-- vector pre header. | | | v | [ ] \ | [ ]_| <-- vector loop. | | - \ v - >[ ] <--- middle-block. - / | - / v + \ v + >[ ] <--- middle-block. + / | + / v | [ ] <--- new preheader. | | | v | [ ] \ | [ ]_| <-- old scalar loop to handle remainder. - \ | - \ v - >[ ] <-- exit block. + \ | + \ v + >[ ] <-- exit block. ... */ @@ -436,6 +1165,11 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { BasicBlock *ExitBlock = OrigLoop->getExitBlock(); assert(ExitBlock && "Must have an exit block"); + // Mark the old scalar loop with metadata that tells us not to vectorize this + // loop again if we run into it. + MDNode *MD = MDNode::get(OldBasicBlock->getContext(), ArrayRef<Value*>()); + OldBasicBlock->getTerminator()->setMetadata(AlreadyVectorizedMDName, MD); + // Some loops have a single integer induction variable, while other loops // don't. One example is c++ iterators that often have multiple pointer // induction variables. In the code below we also support a case where we @@ -468,10 +1202,7 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { ConstantInt::get(IdxTy, 0); assert(BypassBlock && "Invalid loop structure"); - - // Generate the code that checks in runtime if arrays overlap. - Value *MemoryRuntimeCheck = addRuntimeCheck(Legal, - BypassBlock->getTerminator()); + LoopBypassBlocks.push_back(BypassBlock); // Split the single block loop into the two loop structure described above. BasicBlock *VectorPH = @@ -483,17 +1214,19 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { BasicBlock *ScalarPH = MiddleBlock->splitBasicBlock(MiddleBlock->getTerminator(), "scalar.ph"); - // This is the location in which we add all of the logic for bypassing - // the new vector loop. - Instruction *Loc = BypassBlock->getTerminator(); - // Use this IR builder to create the loop instructions (Phi, Br, Cmp) // inside the loop. Builder.SetInsertPoint(VecBody->getFirstInsertionPt()); // Generate the induction variable. Induction = Builder.CreatePHI(IdxTy, 2, "index"); - Constant *Step = ConstantInt::get(IdxTy, VF); + // The loop step is equal to the vectorization factor (num of SIMD elements) + // times the unroll factor (num of SIMD instructions). + Constant *Step = ConstantInt::get(IdxTy, VF * UF); + + // This is the IR builder that we use to add all of the logic for bypassing + // the new vector loop. + IRBuilder<> BypassBuilder(BypassBlock->getTerminator()); // We may need to extend the index in case there is a type mismatch. // We know that the count starts at zero and does not overflow. @@ -501,37 +1234,52 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { // The exit count can be of pointer type. Convert it to the correct // integer type. if (ExitCount->getType()->isPointerTy()) - Count = CastInst::CreatePointerCast(Count, IdxTy, "ptrcnt.to.int", Loc); + Count = BypassBuilder.CreatePointerCast(Count, IdxTy, "ptrcnt.to.int"); else - Count = CastInst::CreateZExtOrBitCast(Count, IdxTy, "zext.cnt", Loc); + Count = BypassBuilder.CreateZExtOrTrunc(Count, IdxTy, "cnt.cast"); } // Add the start index to the loop count to get the new end index. - Value *IdxEnd = BinaryOperator::CreateAdd(Count, StartIdx, "end.idx", Loc); + Value *IdxEnd = BypassBuilder.CreateAdd(Count, StartIdx, "end.idx"); // Now we need to generate the expression for N - (N % VF), which is // the part that the vectorized body will execute. - Constant *CIVF = ConstantInt::get(IdxTy, VF); - Value *R = BinaryOperator::CreateURem(Count, CIVF, "n.mod.vf", Loc); - Value *CountRoundDown = BinaryOperator::CreateSub(Count, R, "n.vec", Loc); - Value *IdxEndRoundDown = BinaryOperator::CreateAdd(CountRoundDown, StartIdx, - "end.idx.rnd.down", Loc); + Value *R = BypassBuilder.CreateURem(Count, Step, "n.mod.vf"); + Value *CountRoundDown = BypassBuilder.CreateSub(Count, R, "n.vec"); + Value *IdxEndRoundDown = BypassBuilder.CreateAdd(CountRoundDown, StartIdx, + "end.idx.rnd.down"); // Now, compare the new count to zero. If it is zero skip the vector loop and // jump to the scalar loop. - Value *Cmp = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, - IdxEndRoundDown, - StartIdx, - "cmp.zero", Loc); - - // If we are using memory runtime checks, include them in. - if (MemoryRuntimeCheck) - Cmp = BinaryOperator::Create(Instruction::Or, Cmp, MemoryRuntimeCheck, - "CntOrMem", Loc); + Value *Cmp = BypassBuilder.CreateICmpEQ(IdxEndRoundDown, StartIdx, + "cmp.zero"); + + BasicBlock *LastBypassBlock = BypassBlock; + + // Generate the code that checks in runtime if arrays overlap. We put the + // checks into a separate block to make the more common case of few elements + // faster. + Instruction *MemRuntimeCheck = addRuntimeCheck(Legal, + BypassBlock->getTerminator()); + if (MemRuntimeCheck) { + // Create a new block containing the memory check. + BasicBlock *CheckBlock = BypassBlock->splitBasicBlock(MemRuntimeCheck, + "vector.memcheck"); + LoopBypassBlocks.push_back(CheckBlock); + + // Replace the branch into the memory check block with a conditional branch + // for the "few elements case". + Instruction *OldTerm = BypassBlock->getTerminator(); + BranchInst::Create(MiddleBlock, CheckBlock, Cmp, OldTerm); + OldTerm->eraseFromParent(); + + Cmp = MemRuntimeCheck; + LastBypassBlock = CheckBlock; + } - BranchInst::Create(MiddleBlock, VectorPH, Cmp, Loc); - // Remove the old terminator. - Loc->eraseFromParent(); + LastBypassBlock->getTerminator()->eraseFromParent(); + BranchInst::Create(MiddleBlock, VectorPH, Cmp, + LastBypassBlock); // We are going to resume the execution of the scalar loop. // Go over all of the induction variables that we found and fix the @@ -552,9 +1300,9 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { MiddleBlock->getTerminator()); Value *EndValue = 0; switch (II.IK) { - case LoopVectorizationLegality::NoInduction: + case LoopVectorizationLegality::IK_NoInduction: llvm_unreachable("Unknown induction"); - case LoopVectorizationLegality::IntInduction: { + case LoopVectorizationLegality::IK_IntInduction: { // Handle the integer induction counter: assert(OrigPhi->getType()->isIntegerTy() && "Invalid type"); assert(OrigPhi == OldInduction && "Unknown integer PHI"); @@ -564,37 +1312,52 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { ResumeIndex = ResumeVal; break; } - case LoopVectorizationLegality::ReverseIntInduction: { + case LoopVectorizationLegality::IK_ReverseIntInduction: { // Convert the CountRoundDown variable to the PHI size. unsigned CRDSize = CountRoundDown->getType()->getScalarSizeInBits(); unsigned IISize = II.StartValue->getType()->getScalarSizeInBits(); Value *CRD = CountRoundDown; if (CRDSize > IISize) CRD = CastInst::Create(Instruction::Trunc, CountRoundDown, - II.StartValue->getType(), - "tr.crd", BypassBlock->getTerminator()); + II.StartValue->getType(), "tr.crd", + LoopBypassBlocks.back()->getTerminator()); else if (CRDSize < IISize) CRD = CastInst::Create(Instruction::SExt, CountRoundDown, II.StartValue->getType(), - "sext.crd", BypassBlock->getTerminator()); + "sext.crd", + LoopBypassBlocks.back()->getTerminator()); // Handle reverse integer induction counter: - EndValue = BinaryOperator::CreateSub(II.StartValue, CRD, "rev.ind.end", - BypassBlock->getTerminator()); + EndValue = + BinaryOperator::CreateSub(II.StartValue, CRD, "rev.ind.end", + LoopBypassBlocks.back()->getTerminator()); break; } - case LoopVectorizationLegality::PtrInduction: { + case LoopVectorizationLegality::IK_PtrInduction: { // For pointer induction variables, calculate the offset using // the end index. - EndValue = GetElementPtrInst::Create(II.StartValue, CountRoundDown, - "ptr.ind.end", - BypassBlock->getTerminator()); + EndValue = + GetElementPtrInst::Create(II.StartValue, CountRoundDown, "ptr.ind.end", + LoopBypassBlocks.back()->getTerminator()); + break; + } + case LoopVectorizationLegality::IK_ReversePtrInduction: { + // The value at the end of the loop for the reverse pointer is calculated + // by creating a GEP with a negative index starting from the start value. + Value *Zero = ConstantInt::get(CountRoundDown->getType(), 0); + Value *NegIdx = BinaryOperator::CreateSub(Zero, CountRoundDown, + "rev.ind.end", + LoopBypassBlocks.back()->getTerminator()); + EndValue = GetElementPtrInst::Create(II.StartValue, NegIdx, + "rev.ptr.ind.end", + LoopBypassBlocks.back()->getTerminator()); break; } }// end of case // The new PHI merges the original incoming value, in case of a bypass, // or the value at the end of the vectorized loop. - ResumeVal->addIncoming(II.StartValue, BypassBlock); + for (unsigned I = 0, E = LoopBypassBlocks.size(); I != E; ++I) + ResumeVal->addIncoming(II.StartValue, LoopBypassBlocks[I]); ResumeVal->addIncoming(EndValue, VecBody); // Fix the scalar body counter (PHI node). @@ -610,7 +1373,8 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { assert(!ResumeIndex && "Unexpected resume value found"); ResumeIndex = PHINode::Create(IdxTy, 2, "new.indc.resume.val", MiddleBlock->getTerminator()); - ResumeIndex->addIncoming(StartIdx, BypassBlock); + for (unsigned I = 0, E = LoopBypassBlocks.size(); I != E; ++I) + ResumeIndex->addIncoming(StartIdx, LoopBypassBlocks[I]); ResumeIndex->addIncoming(IdxEndRoundDown, VecBody); } @@ -650,6 +1414,8 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { // Insert the new loop into the loop nest and register the new basic blocks. if (ParentLoop) { ParentLoop->addChildLoop(Lp); + for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) + ParentLoop->addBasicBlockToLoop(LoopBypassBlocks[I], LI->getBase()); ParentLoop->addBasicBlockToLoop(ScalarPH, LI->getBase()); ParentLoop->addBasicBlockToLoop(VectorPH, LI->getBase()); ParentLoop->addBasicBlockToLoop(MiddleBlock, LI->getBase()); @@ -666,57 +1432,160 @@ InnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { LoopExitBlock = ExitBlock; LoopVectorBody = VecBody; LoopScalarBody = OldBasicBlock; - LoopBypassBlock = BypassBlock; } /// This function returns the identity element (or neutral element) for /// the operation K. -static unsigned -getReductionIdentity(LoopVectorizationLegality::ReductionKind K) { +static Constant* +getReductionIdentity(LoopVectorizationLegality::ReductionKind K, Type *Tp) { switch (K) { - case LoopVectorizationLegality::IntegerXor: - case LoopVectorizationLegality::IntegerAdd: - case LoopVectorizationLegality::IntegerOr: + case LoopVectorizationLegality:: RK_IntegerXor: + case LoopVectorizationLegality:: RK_IntegerAdd: + case LoopVectorizationLegality:: RK_IntegerOr: // Adding, Xoring, Oring zero to a number does not change it. - return 0; - case LoopVectorizationLegality::IntegerMult: + return ConstantInt::get(Tp, 0); + case LoopVectorizationLegality:: RK_IntegerMult: // Multiplying a number by 1 does not change it. - return 1; - case LoopVectorizationLegality::IntegerAnd: + return ConstantInt::get(Tp, 1); + case LoopVectorizationLegality:: RK_IntegerAnd: // AND-ing a number with an all-1 value does not change it. - return -1; + return ConstantInt::get(Tp, -1, true); + case LoopVectorizationLegality:: RK_FloatMult: + // Multiplying a number by 1 does not change it. + return ConstantFP::get(Tp, 1.0L); + case LoopVectorizationLegality:: RK_FloatAdd: + // Adding zero to a number does not change it. + return ConstantFP::get(Tp, 0.0L); default: llvm_unreachable("Unknown reduction kind"); } } -static bool -isTriviallyVectorizableIntrinsic(Instruction *Inst) { - IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst); - if (!II) - return false; - switch (II->getIntrinsicID()) { - case Intrinsic::sqrt: - case Intrinsic::sin: - case Intrinsic::cos: - case Intrinsic::exp: - case Intrinsic::exp2: - case Intrinsic::log: - case Intrinsic::log10: - case Intrinsic::log2: - case Intrinsic::fabs: - case Intrinsic::floor: - case Intrinsic::ceil: - case Intrinsic::trunc: - case Intrinsic::rint: - case Intrinsic::nearbyint: - case Intrinsic::pow: - case Intrinsic::fma: - return true; +static Intrinsic::ID +getIntrinsicIDForCall(CallInst *CI, const TargetLibraryInfo *TLI) { + // If we have an intrinsic call, check if it is trivially vectorizable. + if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI)) { + switch (II->getIntrinsicID()) { + case Intrinsic::sqrt: + case Intrinsic::sin: + case Intrinsic::cos: + case Intrinsic::exp: + case Intrinsic::exp2: + case Intrinsic::log: + case Intrinsic::log10: + case Intrinsic::log2: + case Intrinsic::fabs: + case Intrinsic::floor: + case Intrinsic::ceil: + case Intrinsic::trunc: + case Intrinsic::rint: + case Intrinsic::nearbyint: + case Intrinsic::pow: + case Intrinsic::fma: + case Intrinsic::fmuladd: + return II->getIntrinsicID(); + default: + return Intrinsic::not_intrinsic; + } + } + + if (!TLI) + return Intrinsic::not_intrinsic; + + LibFunc::Func Func; + Function *F = CI->getCalledFunction(); + // We're going to make assumptions on the semantics of the functions, check + // that the target knows that it's available in this environment. + if (!F || !TLI->getLibFunc(F->getName(), Func)) + return Intrinsic::not_intrinsic; + + // Otherwise check if we have a call to a function that can be turned into a + // vector intrinsic. + switch (Func) { default: - return false; + break; + case LibFunc::sin: + case LibFunc::sinf: + case LibFunc::sinl: + return Intrinsic::sin; + case LibFunc::cos: + case LibFunc::cosf: + case LibFunc::cosl: + return Intrinsic::cos; + case LibFunc::exp: + case LibFunc::expf: + case LibFunc::expl: + return Intrinsic::exp; + case LibFunc::exp2: + case LibFunc::exp2f: + case LibFunc::exp2l: + return Intrinsic::exp2; + case LibFunc::log: + case LibFunc::logf: + case LibFunc::logl: + return Intrinsic::log; + case LibFunc::log10: + case LibFunc::log10f: + case LibFunc::log10l: + return Intrinsic::log10; + case LibFunc::log2: + case LibFunc::log2f: + case LibFunc::log2l: + return Intrinsic::log2; + case LibFunc::fabs: + case LibFunc::fabsf: + case LibFunc::fabsl: + return Intrinsic::fabs; + case LibFunc::floor: + case LibFunc::floorf: + case LibFunc::floorl: + return Intrinsic::floor; + case LibFunc::ceil: + case LibFunc::ceilf: + case LibFunc::ceill: + return Intrinsic::ceil; + case LibFunc::trunc: + case LibFunc::truncf: + case LibFunc::truncl: + return Intrinsic::trunc; + case LibFunc::rint: + case LibFunc::rintf: + case LibFunc::rintl: + return Intrinsic::rint; + case LibFunc::nearbyint: + case LibFunc::nearbyintf: + case LibFunc::nearbyintl: + return Intrinsic::nearbyint; + case LibFunc::pow: + case LibFunc::powf: + case LibFunc::powl: + return Intrinsic::pow; + } + + return Intrinsic::not_intrinsic; +} + +/// This function translates the reduction kind to an LLVM binary operator. +static Instruction::BinaryOps +getReductionBinOp(LoopVectorizationLegality::ReductionKind Kind) { + switch (Kind) { + case LoopVectorizationLegality::RK_IntegerAdd: + return Instruction::Add; + case LoopVectorizationLegality::RK_IntegerMult: + return Instruction::Mul; + case LoopVectorizationLegality::RK_IntegerOr: + return Instruction::Or; + case LoopVectorizationLegality::RK_IntegerAnd: + return Instruction::And; + case LoopVectorizationLegality::RK_IntegerXor: + return Instruction::Xor; + case LoopVectorizationLegality::RK_FloatMult: + return Instruction::FMul; + case LoopVectorizationLegality::RK_FloatAdd: + return Instruction::FAdd; + default: + llvm_unreachable("Unknown reduction operation"); } - return false; } void @@ -728,9 +1597,7 @@ InnerLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) { // the cost-model. // //===------------------------------------------------===// - BasicBlock &BB = *OrigLoop->getHeader(); - Constant *Zero = - ConstantInt::get(IntegerType::getInt32Ty(BB.getContext()), 0); + Constant *Zero = Builder.getInt32(0); // In order to support reduction variables we need to be able to vectorize // Phi nodes. Phi nodes have cycles, so we need to vectorize them in two @@ -764,7 +1631,6 @@ InnerLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) { for (PhiVector::iterator it = RdxPHIsToFix.begin(), e = RdxPHIsToFix.end(); it != e; ++it) { PHINode *RdxPhi = *it; - PHINode *VecRdxPhi = dyn_cast<PHINode>(WidenMap[RdxPhi]); assert(RdxPhi && "Unable to recover vectorized PHI"); // Find the reduction variable descriptor. @@ -777,16 +1643,16 @@ InnerLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) { // To do so, we need to generate the 'identity' vector and overide // one of the elements with the incoming scalar reduction. We need // to do it in the vector-loop preheader. - Builder.SetInsertPoint(LoopBypassBlock->getTerminator()); + Builder.SetInsertPoint(LoopBypassBlocks.front()->getTerminator()); // This is the vector-clone of the value that leaves the loop. - Value *VectorExit = getVectorValue(RdxDesc.LoopExitInstr); - Type *VecTy = VectorExit->getType(); + VectorParts &VectorExit = getVectorValue(RdxDesc.LoopExitInstr); + Type *VecTy = VectorExit[0]->getType(); // Find the reduction identity variable. Zero for addition, or, xor, // one for multiplication, -1 for And. - Constant *Identity = getUniformVector(getReductionIdentity(RdxDesc.Kind), - VecTy->getScalarType()); + Constant *Iden = getReductionIdentity(RdxDesc.Kind, VecTy->getScalarType()); + Constant *Identity = ConstantVector::getSplat(VF, Iden); // This vector is the Identity vector where the first element is the // incoming scalar reduction. @@ -800,10 +1666,17 @@ InnerLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) { // Reductions do not have to start at zero. They can start with // any loop invariant values. - VecRdxPhi->addIncoming(VectorStart, VecPreheader); - Value *Val = - getVectorValue(RdxPhi->getIncomingValueForBlock(OrigLoop->getLoopLatch())); - VecRdxPhi->addIncoming(Val, LoopVectorBody); + VectorParts &VecRdxPhi = WidenMap.get(RdxPhi); + BasicBlock *Latch = OrigLoop->getLoopLatch(); + Value *LoopVal = RdxPhi->getIncomingValueForBlock(Latch); + VectorParts &Val = getVectorValue(LoopVal); + for (unsigned part = 0; part < UF; ++part) { + // Make sure to add the reduction stat value only to the + // first unroll part. + Value *StartVal = (part == 0) ? VectorStart : Identity; + cast<PHINode>(VecRdxPhi[part])->addIncoming(StartVal, VecPreheader); + cast<PHINode>(VecRdxPhi[part])->addIncoming(Val[part], LoopVectorBody); + } // Before each round, move the insertion point right between // the PHIs and the values we are going to write. @@ -811,40 +1684,56 @@ InnerLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) { // instructions. Builder.SetInsertPoint(LoopMiddleBlock->getFirstInsertionPt()); - // This PHINode contains the vectorized reduction variable, or - // the initial value vector, if we bypass the vector loop. - PHINode *NewPhi = Builder.CreatePHI(VecTy, 2, "rdx.vec.exit.phi"); - NewPhi->addIncoming(VectorStart, LoopBypassBlock); - NewPhi->addIncoming(getVectorValue(RdxDesc.LoopExitInstr), LoopVectorBody); - - // Extract the first scalar. - Value *Scalar0 = - Builder.CreateExtractElement(NewPhi, Builder.getInt32(0)); - // Extract and reduce the remaining vector elements. - for (unsigned i=1; i < VF; ++i) { - Value *Scalar1 = - Builder.CreateExtractElement(NewPhi, Builder.getInt32(i)); - switch (RdxDesc.Kind) { - case LoopVectorizationLegality::IntegerAdd: - Scalar0 = Builder.CreateAdd(Scalar0, Scalar1, "add.rdx"); - break; - case LoopVectorizationLegality::IntegerMult: - Scalar0 = Builder.CreateMul(Scalar0, Scalar1, "mul.rdx"); - break; - case LoopVectorizationLegality::IntegerOr: - Scalar0 = Builder.CreateOr(Scalar0, Scalar1, "or.rdx"); - break; - case LoopVectorizationLegality::IntegerAnd: - Scalar0 = Builder.CreateAnd(Scalar0, Scalar1, "and.rdx"); - break; - case LoopVectorizationLegality::IntegerXor: - Scalar0 = Builder.CreateXor(Scalar0, Scalar1, "xor.rdx"); - break; - default: - llvm_unreachable("Unknown reduction operation"); - } + VectorParts RdxParts; + for (unsigned part = 0; part < UF; ++part) { + // This PHINode contains the vectorized reduction variable, or + // the initial value vector, if we bypass the vector loop. + VectorParts &RdxExitVal = getVectorValue(RdxDesc.LoopExitInstr); + PHINode *NewPhi = Builder.CreatePHI(VecTy, 2, "rdx.vec.exit.phi"); + Value *StartVal = (part == 0) ? VectorStart : Identity; + for (unsigned I = 0, E = LoopBypassBlocks.size(); I != E; ++I) + NewPhi->addIncoming(StartVal, LoopBypassBlocks[I]); + NewPhi->addIncoming(RdxExitVal[part], LoopVectorBody); + RdxParts.push_back(NewPhi); + } + + // Reduce all of the unrolled parts into a single vector. + Value *ReducedPartRdx = RdxParts[0]; + for (unsigned part = 1; part < UF; ++part) { + Instruction::BinaryOps Op = getReductionBinOp(RdxDesc.Kind); + ReducedPartRdx = Builder.CreateBinOp(Op, RdxParts[part], ReducedPartRdx, + "bin.rdx"); } + // VF is a power of 2 so we can emit the reduction using log2(VF) shuffles + // and vector ops, reducing the set of values being computed by half each + // round. + assert(isPowerOf2_32(VF) && + "Reduction emission only supported for pow2 vectors!"); + Value *TmpVec = ReducedPartRdx; + SmallVector<Constant*, 32> ShuffleMask(VF, 0); + for (unsigned i = VF; i != 1; i >>= 1) { + // Move the upper half of the vector to the lower half. + for (unsigned j = 0; j != i/2; ++j) + ShuffleMask[j] = Builder.getInt32(i/2 + j); + + // Fill the rest of the mask with undef. + std::fill(&ShuffleMask[i/2], ShuffleMask.end(), + UndefValue::get(Builder.getInt32Ty())); + + Value *Shuf = + Builder.CreateShuffleVector(TmpVec, + UndefValue::get(TmpVec->getType()), + ConstantVector::get(ShuffleMask), + "rdx.shuf"); + + Instruction::BinaryOps Op = getReductionBinOp(RdxDesc.Kind); + TmpVec = Builder.CreateBinOp(Op, TmpVec, Shuf, "bin.rdx"); + } + + // The result is in the first element of the vector. + Value *Scalar0 = Builder.CreateExtractElement(TmpVec, Builder.getInt32(0)); + // Now, we need to fix the users of the reduction variable // inside and outside of the scalar remainder loop. // We know that the loop is in LCSSA form. We need to update the @@ -877,29 +1766,49 @@ InnerLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) { (RdxPhi)->setIncomingValue(SelfEdgeBlockIdx, Scalar0); (RdxPhi)->setIncomingValue(IncomingEdgeBlockIdx, RdxDesc.LoopExitInstr); }// end of for each redux variable. + + // The Loop exit block may have single value PHI nodes where the incoming + // value is 'undef'. While vectorizing we only handled real values that + // were defined inside the loop. Here we handle the 'undef case'. + // See PR14725. + for (BasicBlock::iterator LEI = LoopExitBlock->begin(), + LEE = LoopExitBlock->end(); LEI != LEE; ++LEI) { + PHINode *LCSSAPhi = dyn_cast<PHINode>(LEI); + if (!LCSSAPhi) continue; + if (LCSSAPhi->getNumIncomingValues() == 1) + LCSSAPhi->addIncoming(UndefValue::get(LCSSAPhi->getType()), + LoopMiddleBlock); + } } -Value *InnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) { +InnerLoopVectorizer::VectorParts +InnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) { assert(std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end(Dst) && "Invalid edge"); - Value *SrcMask = createBlockInMask(Src); + VectorParts SrcMask = createBlockInMask(Src); // The terminator has to be a branch inst! BranchInst *BI = dyn_cast<BranchInst>(Src->getTerminator()); assert(BI && "Unexpected terminator found"); - Value *EdgeMask = SrcMask; if (BI->isConditional()) { - EdgeMask = getVectorValue(BI->getCondition()); + VectorParts EdgeMask = getVectorValue(BI->getCondition()); + if (BI->getSuccessor(0) != Dst) - EdgeMask = Builder.CreateNot(EdgeMask); + for (unsigned part = 0; part < UF; ++part) + EdgeMask[part] = Builder.CreateNot(EdgeMask[part]); + + for (unsigned part = 0; part < UF; ++part) + EdgeMask[part] = Builder.CreateAnd(EdgeMask[part], SrcMask[part]); + return EdgeMask; } - return Builder.CreateAnd(EdgeMask, SrcMask); + return SrcMask; } -Value *InnerLoopVectorizer::createBlockInMask(BasicBlock *BB) { +InnerLoopVectorizer::VectorParts +InnerLoopVectorizer::createBlockInMask(BasicBlock *BB) { assert(OrigLoop->contains(BB) && "Block is not a part of a loop"); // Loop incoming mask is all-one. @@ -910,11 +1819,14 @@ Value *InnerLoopVectorizer::createBlockInMask(BasicBlock *BB) { // This is the block mask. We OR all incoming edges, and with zero. Value *Zero = ConstantInt::get(IntegerType::getInt1Ty(BB->getContext()), 0); - Value *BlockMask = getVectorValue(Zero); + VectorParts BlockMask = getVectorValue(Zero); // For each pred: - for (pred_iterator it = pred_begin(BB), e = pred_end(BB); it != e; ++it) - BlockMask = Builder.CreateOr(BlockMask, createEdgeMask(*it, BB)); + for (pred_iterator it = pred_begin(BB), e = pred_end(BB); it != e; ++it) { + VectorParts EM = createEdgeMask(*it, BB); + for (unsigned part = 0; part < UF; ++part) + BlockMask[part] = Builder.CreateOr(BlockMask[part], EM[part]); + } return BlockMask; } @@ -922,11 +1834,9 @@ Value *InnerLoopVectorizer::createBlockInMask(BasicBlock *BB) { void InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, BasicBlock *BB, PhiVector *PV) { - Constant *Zero = - ConstantInt::get(IntegerType::getInt32Ty(BB->getContext()), 0); - // For each instruction in the old loop. for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { + VectorParts &Entry = WidenMap.get(it); switch (it->getOpcode()) { case Instruction::Br: // Nothing to do for PHIs and BR, since we already took care of the @@ -936,11 +1846,12 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, PHINode* P = cast<PHINode>(it); // Handle reduction variables: if (Legal->getReductionVars()->count(P)) { - // This is phase one of vectorizing PHIs. - Type *VecTy = VectorType::get(it->getType(), VF); - WidenMap[it] = - PHINode::Create(VecTy, 2, "vec.phi", - LoopVectorBody->getFirstInsertionPt()); + for (unsigned part = 0; part < UF; ++part) { + // This is phase one of vectorizing PHIs. + Type *VecTy = VectorType::get(it->getType(), VF); + Entry[part] = PHINode::Create(VecTy, 2, "vec.phi", + LoopVectorBody-> getFirstInsertionPt()); + } PV->push_back(P); continue; } @@ -954,12 +1865,15 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, // At this point we generate the predication tree. There may be // duplications since this is a simple recursive scan, but future // optimizations will clean it up. - Value *Cond = createBlockInMask(P->getIncomingBlock(0)); - WidenMap[P] = - Builder.CreateSelect(Cond, - getVectorValue(P->getIncomingValue(0)), - getVectorValue(P->getIncomingValue(1)), - "predphi"); + VectorParts Cond = createEdgeMask(P->getIncomingBlock(0), + P->getParent()); + + for (unsigned part = 0; part < UF; ++part) { + VectorParts &In0 = getVectorValue(P->getIncomingValue(0)); + VectorParts &In1 = getVectorValue(P->getIncomingValue(1)); + Entry[part] = Builder.CreateSelect(Cond[part], In0[part], In1[part], + "predphi"); + } continue; } @@ -972,19 +1886,20 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, Legal->getInductionVars()->lookup(P); switch (II.IK) { - case LoopVectorizationLegality::NoInduction: + case LoopVectorizationLegality::IK_NoInduction: llvm_unreachable("Unknown induction"); - case LoopVectorizationLegality::IntInduction: { + case LoopVectorizationLegality::IK_IntInduction: { assert(P == OldInduction && "Unexpected PHI"); Value *Broadcasted = getBroadcastInstrs(Induction); // After broadcasting the induction variable we need to make the // vector consecutive by adding 0, 1, 2 ... - Value *ConsecutiveInduction = getConsecutiveVector(Broadcasted); - WidenMap[OldInduction] = ConsecutiveInduction; + for (unsigned part = 0; part < UF; ++part) + Entry[part] = getConsecutiveVector(Broadcasted, VF * part, false); continue; } - case LoopVectorizationLegality::ReverseIntInduction: - case LoopVectorizationLegality::PtrInduction: + case LoopVectorizationLegality::IK_ReverseIntInduction: + case LoopVectorizationLegality::IK_PtrInduction: + case LoopVectorizationLegality::IK_ReversePtrInduction: // Handle reverse integer and pointer inductions. Value *StartIdx = 0; // If we have a single integer induction variable then use it. @@ -1001,7 +1916,7 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, "normalized.idx"); // Handle the reverse integer induction variable case. - if (LoopVectorizationLegality::ReverseIntInduction == II.IK) { + if (LoopVectorizationLegality::IK_ReverseIntInduction == II.IK) { IntegerType *DstTy = cast<IntegerType>(II.StartValue->getType()); Value *CNI = Builder.CreateSExtOrTrunc(NormalizedIdx, DstTy, "resize.norm.idx"); @@ -1012,30 +1927,39 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, Value *Broadcasted = getBroadcastInstrs(ReverseInd); // After broadcasting the induction variable we need to make the // vector consecutive by adding ... -3, -2, -1, 0. - Value *ConsecutiveInduction = getConsecutiveVector(Broadcasted, - true); - WidenMap[it] = ConsecutiveInduction; + for (unsigned part = 0; part < UF; ++part) + Entry[part] = getConsecutiveVector(Broadcasted, -VF * part, true); continue; } // Handle the pointer induction variable case. assert(P->getType()->isPointerTy() && "Unexpected type."); + // Is this a reverse induction ptr or a consecutive induction ptr. + bool Reverse = (LoopVectorizationLegality::IK_ReversePtrInduction == + II.IK); + // This is the vector of results. Notice that we don't generate // vector geps because scalar geps result in better code. - Value *VecVal = UndefValue::get(VectorType::get(P->getType(), VF)); - for (unsigned int i = 0; i < VF; ++i) { - Constant *Idx = ConstantInt::get(Induction->getType(), i); - Value *GlobalIdx = Builder.CreateAdd(NormalizedIdx, Idx, - "gep.idx"); - Value *SclrGep = Builder.CreateGEP(II.StartValue, GlobalIdx, - "next.gep"); - VecVal = Builder.CreateInsertElement(VecVal, SclrGep, - Builder.getInt32(i), - "insert.gep"); + for (unsigned part = 0; part < UF; ++part) { + Value *VecVal = UndefValue::get(VectorType::get(P->getType(), VF)); + for (unsigned int i = 0; i < VF; ++i) { + int EltIndex = (i + part * VF) * (Reverse ? -1 : 1); + Constant *Idx = ConstantInt::get(Induction->getType(), EltIndex); + Value *GlobalIdx; + if (!Reverse) + GlobalIdx = Builder.CreateAdd(NormalizedIdx, Idx, "gep.idx"); + else + GlobalIdx = Builder.CreateSub(Idx, NormalizedIdx, "gep.ridx"); + + Value *SclrGep = Builder.CreateGEP(II.StartValue, GlobalIdx, + "next.gep"); + VecVal = Builder.CreateInsertElement(VecVal, SclrGep, + Builder.getInt32(i), + "insert.gep"); + } + Entry[part] = VecVal; } - - WidenMap[it] = VecVal; continue; } @@ -1061,41 +1985,48 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, case Instruction::Xor: { // Just widen binops. BinaryOperator *BinOp = dyn_cast<BinaryOperator>(it); - Value *A = getVectorValue(it->getOperand(0)); - Value *B = getVectorValue(it->getOperand(1)); + VectorParts &A = getVectorValue(it->getOperand(0)); + VectorParts &B = getVectorValue(it->getOperand(1)); // Use this vector value for all users of the original instruction. - Value *V = Builder.CreateBinOp(BinOp->getOpcode(), A, B); - WidenMap[it] = V; - - // Update the NSW, NUW and Exact flags. - BinaryOperator *VecOp = cast<BinaryOperator>(V); - if (isa<OverflowingBinaryOperator>(BinOp)) { - VecOp->setHasNoSignedWrap(BinOp->hasNoSignedWrap()); - VecOp->setHasNoUnsignedWrap(BinOp->hasNoUnsignedWrap()); + for (unsigned Part = 0; Part < UF; ++Part) { + Value *V = Builder.CreateBinOp(BinOp->getOpcode(), A[Part], B[Part]); + + // Update the NSW, NUW and Exact flags. Notice: V can be an Undef. + BinaryOperator *VecOp = dyn_cast<BinaryOperator>(V); + if (VecOp && isa<OverflowingBinaryOperator>(BinOp)) { + VecOp->setHasNoSignedWrap(BinOp->hasNoSignedWrap()); + VecOp->setHasNoUnsignedWrap(BinOp->hasNoUnsignedWrap()); + } + if (VecOp && isa<PossiblyExactOperator>(VecOp)) + VecOp->setIsExact(BinOp->isExact()); + + Entry[Part] = V; } - if (isa<PossiblyExactOperator>(VecOp)) - VecOp->setIsExact(BinOp->isExact()); break; } case Instruction::Select: { // Widen selects. // If the selector is loop invariant we can create a select // instruction with a scalar condition. Otherwise, use vector-select. - Value *Cond = it->getOperand(0); - bool InvariantCond = SE->isLoopInvariant(SE->getSCEV(Cond), OrigLoop); + bool InvariantCond = SE->isLoopInvariant(SE->getSCEV(it->getOperand(0)), + OrigLoop); // The condition can be loop invariant but still defined inside the // loop. This means that we can't just use the original 'cond' value. // We have to take the 'vectorized' value and pick the first lane. // Instcombine will make this a no-op. - Cond = getVectorValue(Cond); - if (InvariantCond) - Cond = Builder.CreateExtractElement(Cond, Builder.getInt32(0)); - - Value *Op0 = getVectorValue(it->getOperand(1)); - Value *Op1 = getVectorValue(it->getOperand(2)); - WidenMap[it] = Builder.CreateSelect(Cond, Op0, Op1); + VectorParts &Cond = getVectorValue(it->getOperand(0)); + VectorParts &Op0 = getVectorValue(it->getOperand(1)); + VectorParts &Op1 = getVectorValue(it->getOperand(2)); + Value *ScalarCond = Builder.CreateExtractElement(Cond[0], + Builder.getInt32(0)); + for (unsigned Part = 0; Part < UF; ++Part) { + Entry[Part] = Builder.CreateSelect( + InvariantCond ? ScalarCond : Cond[Part], + Op0[Part], + Op1[Part]); + } break; } @@ -1104,94 +2035,23 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, // Widen compares. Generate vector compares. bool FCmp = (it->getOpcode() == Instruction::FCmp); CmpInst *Cmp = dyn_cast<CmpInst>(it); - Value *A = getVectorValue(it->getOperand(0)); - Value *B = getVectorValue(it->getOperand(1)); - if (FCmp) - WidenMap[it] = Builder.CreateFCmp(Cmp->getPredicate(), A, B); - else - WidenMap[it] = Builder.CreateICmp(Cmp->getPredicate(), A, B); - break; - } - - case Instruction::Store: { - // Attempt to issue a wide store. - StoreInst *SI = dyn_cast<StoreInst>(it); - Type *StTy = VectorType::get(SI->getValueOperand()->getType(), VF); - Value *Ptr = SI->getPointerOperand(); - unsigned Alignment = SI->getAlignment(); - - assert(!Legal->isUniform(Ptr) && - "We do not allow storing to uniform addresses"); - - GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr); - - // This store does not use GEPs. - if (!Legal->isConsecutivePtr(Ptr)) { - scalarizeInstruction(it); - break; + VectorParts &A = getVectorValue(it->getOperand(0)); + VectorParts &B = getVectorValue(it->getOperand(1)); + for (unsigned Part = 0; Part < UF; ++Part) { + Value *C = 0; + if (FCmp) + C = Builder.CreateFCmp(Cmp->getPredicate(), A[Part], B[Part]); + else + C = Builder.CreateICmp(Cmp->getPredicate(), A[Part], B[Part]); + Entry[Part] = C; } - - if (Gep) { - // The last index does not have to be the induction. It can be - // consecutive and be a function of the index. For example A[I+1]; - unsigned NumOperands = Gep->getNumOperands(); - Value *LastIndex = getVectorValue(Gep->getOperand(NumOperands - 1)); - LastIndex = Builder.CreateExtractElement(LastIndex, Zero); - - // Create the new GEP with the new induction variable. - GetElementPtrInst *Gep2 = cast<GetElementPtrInst>(Gep->clone()); - Gep2->setOperand(NumOperands - 1, LastIndex); - Ptr = Builder.Insert(Gep2); - } else { - // Use the induction element ptr. - assert(isa<PHINode>(Ptr) && "Invalid induction ptr"); - Ptr = Builder.CreateExtractElement(getVectorValue(Ptr), Zero); - } - Ptr = Builder.CreateBitCast(Ptr, StTy->getPointerTo()); - Value *Val = getVectorValue(SI->getValueOperand()); - Builder.CreateStore(Val, Ptr)->setAlignment(Alignment); break; } - case Instruction::Load: { - // Attempt to issue a wide load. - LoadInst *LI = dyn_cast<LoadInst>(it); - Type *RetTy = VectorType::get(LI->getType(), VF); - Value *Ptr = LI->getPointerOperand(); - unsigned Alignment = LI->getAlignment(); - GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr); - - // If the pointer is loop invariant or if it is non consecutive, - // scalarize the load. - bool Con = Legal->isConsecutivePtr(Ptr); - if (Legal->isUniform(Ptr) || !Con) { - scalarizeInstruction(it); - break; - } - - if (Gep) { - // The last index does not have to be the induction. It can be - // consecutive and be a function of the index. For example A[I+1]; - unsigned NumOperands = Gep->getNumOperands(); - Value *LastIndex = getVectorValue(Gep->getOperand(NumOperands -1)); - LastIndex = Builder.CreateExtractElement(LastIndex, Zero); - - // Create the new GEP with the new induction variable. - GetElementPtrInst *Gep2 = cast<GetElementPtrInst>(Gep->clone()); - Gep2->setOperand(NumOperands - 1, LastIndex); - Ptr = Builder.Insert(Gep2); - } else { - // Use the induction element ptr. - assert(isa<PHINode>(Ptr) && "Invalid induction ptr"); - Ptr = Builder.CreateExtractElement(getVectorValue(Ptr), Zero); - } - Ptr = Builder.CreateBitCast(Ptr, RetTy->getPointerTo()); - LI = Builder.CreateLoad(Ptr); - LI->setAlignment(Alignment); - // Use this vector value for all users of the load. - WidenMap[it] = LI; - break; - } + case Instruction::Store: + case Instruction::Load: + vectorizeMemoryInstruction(it, Legal); + break; case Instruction::ZExt: case Instruction::SExt: case Instruction::FPToUI: @@ -1204,25 +2064,48 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, case Instruction::Trunc: case Instruction::FPTrunc: case Instruction::BitCast: { - /// Vectorize bitcasts. CastInst *CI = dyn_cast<CastInst>(it); - Value *A = getVectorValue(it->getOperand(0)); + /// Optimize the special case where the source is the induction + /// variable. Notice that we can only optimize the 'trunc' case + /// because: a. FP conversions lose precision, b. sext/zext may wrap, + /// c. other casts depend on pointer size. + if (CI->getOperand(0) == OldInduction && + it->getOpcode() == Instruction::Trunc) { + Value *ScalarCast = Builder.CreateCast(CI->getOpcode(), Induction, + CI->getType()); + Value *Broadcasted = getBroadcastInstrs(ScalarCast); + for (unsigned Part = 0; Part < UF; ++Part) + Entry[Part] = getConsecutiveVector(Broadcasted, VF * Part, false); + break; + } + /// Vectorize casts. Type *DestTy = VectorType::get(CI->getType()->getScalarType(), VF); - WidenMap[it] = Builder.CreateCast(CI->getOpcode(), A, DestTy); + + VectorParts &A = getVectorValue(it->getOperand(0)); + for (unsigned Part = 0; Part < UF; ++Part) + Entry[Part] = Builder.CreateCast(CI->getOpcode(), A[Part], DestTy); break; } case Instruction::Call: { - assert(isTriviallyVectorizableIntrinsic(it)); + // Ignore dbg intrinsics. + if (isa<DbgInfoIntrinsic>(it)) + break; + Module *M = BB->getParent()->getParent(); - IntrinsicInst *II = cast<IntrinsicInst>(it); - Intrinsic::ID ID = II->getIntrinsicID(); - SmallVector<Value*, 4> Args; - for (unsigned i = 0, ie = II->getNumArgOperands(); i != ie; ++i) - Args.push_back(getVectorValue(II->getArgOperand(i))); - Type *Tys[] = { VectorType::get(II->getType()->getScalarType(), VF) }; - Function *F = Intrinsic::getDeclaration(M, ID, Tys); - WidenMap[it] = Builder.CreateCall(F, Args); + CallInst *CI = cast<CallInst>(it); + Intrinsic::ID ID = getIntrinsicIDForCall(CI, TLI); + assert(ID && "Not an intrinsic call!"); + for (unsigned Part = 0; Part < UF; ++Part) { + SmallVector<Value*, 4> Args; + for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) { + VectorParts &Arg = getVectorValue(CI->getArgOperand(i)); + Args.push_back(Arg[Part]); + } + Type *Tys[] = { VectorType::get(CI->getType()->getScalarType(), VF) }; + Function *F = Intrinsic::getDeclaration(M, ID, Tys); + Entry[Part] = Builder.CreateCall(F, Args); + } break; } @@ -1239,12 +2122,14 @@ void InnerLoopVectorizer::updateAnalysis() { SE->forgetLoop(OrigLoop); // Update the dominator tree information. - assert(DT->properlyDominates(LoopBypassBlock, LoopExitBlock) && + assert(DT->properlyDominates(LoopBypassBlocks.front(), LoopExitBlock) && "Entry does not dominate exit."); - DT->addNewBlock(LoopVectorPreHeader, LoopBypassBlock); + for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) + DT->addNewBlock(LoopBypassBlocks[I], LoopBypassBlocks[I-1]); + DT->addNewBlock(LoopVectorPreHeader, LoopBypassBlocks.back()); DT->addNewBlock(LoopVectorBody, LoopVectorPreHeader); - DT->addNewBlock(LoopMiddleBlock, LoopBypassBlock); + DT->addNewBlock(LoopMiddleBlock, LoopBypassBlocks.front()); DT->addNewBlock(LoopScalarPreHeader, LoopMiddleBlock); DT->changeImmediateDominator(LoopScalarBody, LoopScalarPreHeader); DT->changeImmediateDominator(LoopExitBlock, LoopMiddleBlock); @@ -1263,6 +2148,10 @@ bool LoopVectorizationLegality::canVectorizeWithIfConvert() { for (unsigned i = 0, e = LoopBlocks.size(); i < e; ++i) { BasicBlock *BB = LoopBlocks[i]; + // We don't support switch statements inside loops. + if (!isa<BranchInst>(BB->getTerminator())) + return false; + // We must have at most two predecessors because we need to convert // all PHIs to selects. unsigned Preds = std::distance(pred_begin(BB), pred_end(BB)); @@ -1315,7 +2204,7 @@ bool LoopVectorizationLegality::canVectorize() { // Do not loop-vectorize loops with a tiny trip count. unsigned TC = SE->getSmallConstantTripCount(TheLoop, Latch); - if (TC > 0u && TC < TinyTripCountThreshold) { + if (TC > 0u && TC < TinyTripCountVectorThreshold) { DEBUG(dbgs() << "LV: Found a loop with a very small trip count. " << "This loop is not worth vectorizing.\n"); return false; @@ -1350,6 +2239,13 @@ bool LoopVectorizationLegality::canVectorizeInstrs() { BasicBlock *PreHeader = TheLoop->getLoopPreheader(); BasicBlock *Header = TheLoop->getHeader(); + // If we marked the scalar loop as "already vectorized" then no need + // to vectorize it again. + if (Header->getTerminator()->getMetadata(AlreadyVectorizedMDName)) { + DEBUG(dbgs() << "LV: This loop was vectorized before\n"); + return false; + } + // For each block in the loop. for (Loop::block_iterator bb = TheLoop->block_begin(), be = TheLoop->block_end(); bb != be; ++bb) { @@ -1367,6 +2263,7 @@ bool LoopVectorizationLegality::canVectorizeInstrs() { // Check that this PHI type is allowed. if (!Phi->getType()->isIntegerTy() && + !Phi->getType()->isFloatingPointTy() && !Phi->getType()->isPointerTy()) { DEBUG(dbgs() << "LV: Found an non-int non-pointer PHI.\n"); return false; @@ -1383,9 +2280,9 @@ bool LoopVectorizationLegality::canVectorizeInstrs() { // Check if this is an induction variable. InductionKind IK = isInductionVariable(Phi); - if (NoInduction != IK) { + if (IK_NoInduction != IK) { // Int inductions are special because we only allow one IV. - if (IK == IntInduction) { + if (IK == IK_IntInduction) { if (Induction) { DEBUG(dbgs() << "LV: Found too many inductions."<< *Phi <<"\n"); return false; @@ -1398,45 +2295,61 @@ bool LoopVectorizationLegality::canVectorizeInstrs() { continue; } - if (AddReductionVar(Phi, IntegerAdd)) { + if (AddReductionVar(Phi, RK_IntegerAdd)) { DEBUG(dbgs() << "LV: Found an ADD reduction PHI."<< *Phi <<"\n"); continue; } - if (AddReductionVar(Phi, IntegerMult)) { + if (AddReductionVar(Phi, RK_IntegerMult)) { DEBUG(dbgs() << "LV: Found a MUL reduction PHI."<< *Phi <<"\n"); continue; } - if (AddReductionVar(Phi, IntegerOr)) { + if (AddReductionVar(Phi, RK_IntegerOr)) { DEBUG(dbgs() << "LV: Found an OR reduction PHI."<< *Phi <<"\n"); continue; } - if (AddReductionVar(Phi, IntegerAnd)) { + if (AddReductionVar(Phi, RK_IntegerAnd)) { DEBUG(dbgs() << "LV: Found an AND reduction PHI."<< *Phi <<"\n"); continue; } - if (AddReductionVar(Phi, IntegerXor)) { + if (AddReductionVar(Phi, RK_IntegerXor)) { DEBUG(dbgs() << "LV: Found a XOR reduction PHI."<< *Phi <<"\n"); continue; } + if (AddReductionVar(Phi, RK_FloatMult)) { + DEBUG(dbgs() << "LV: Found an FMult reduction PHI."<< *Phi <<"\n"); + continue; + } + if (AddReductionVar(Phi, RK_FloatAdd)) { + DEBUG(dbgs() << "LV: Found an FAdd reduction PHI."<< *Phi <<"\n"); + continue; + } DEBUG(dbgs() << "LV: Found an unidentified PHI."<< *Phi <<"\n"); return false; }// end of PHI handling - // We still don't handle functions. + // We still don't handle functions. However, we can ignore dbg intrinsic + // calls and we do handle certain intrinsic and libm functions. CallInst *CI = dyn_cast<CallInst>(it); - if (CI && !isTriviallyVectorizableIntrinsic(it)) { + if (CI && !getIntrinsicIDForCall(CI, TLI) && !isa<DbgInfoIntrinsic>(CI)) { DEBUG(dbgs() << "LV: Found a call site.\n"); return false; } - // We do not re-vectorize vectors. + // Check that the instruction return type is vectorizable. if (!VectorType::isValidElementType(it->getType()) && !it->getType()->isVoidTy()) { DEBUG(dbgs() << "LV: Found unvectorizable type." << "\n"); return false; } + // Check that the stored type is vectorizable. + if (StoreInst *ST = dyn_cast<StoreInst>(it)) { + Type *T = ST->getValueOperand()->getType(); + if (!VectorType::isValidElementType(T)) + return false; + } + // Reduction instructions are allowed to have exit users. // All other instructions must not have external users. if (!AllowedExit.count(it)) @@ -1491,7 +2404,51 @@ void LoopVectorizationLegality::collectLoopUniforms() { } } +AliasAnalysis::Location +LoopVectorizationLegality::getLoadStoreLocation(Instruction *Inst) { + if (StoreInst *Store = dyn_cast<StoreInst>(Inst)) + return AA->getLocation(Store); + else if (LoadInst *Load = dyn_cast<LoadInst>(Inst)) + return AA->getLocation(Load); + + llvm_unreachable("Should be either load or store instruction"); +} + +bool +LoopVectorizationLegality::hasPossibleGlobalWriteReorder( + Value *Object, + Instruction *Inst, + AliasMultiMap& WriteObjects, + unsigned MaxByteWidth) { + + AliasAnalysis::Location ThisLoc = getLoadStoreLocation(Inst); + + std::vector<Instruction*>::iterator + it = WriteObjects[Object].begin(), + end = WriteObjects[Object].end(); + + for (; it != end; ++it) { + Instruction* I = *it; + if (I == Inst) + continue; + + AliasAnalysis::Location ThatLoc = getLoadStoreLocation(I); + if (AA->alias(ThisLoc.getWithNewSize(MaxByteWidth), + ThatLoc.getWithNewSize(MaxByteWidth))) + return true; + } + return false; +} + bool LoopVectorizationLegality::canVectorizeMemory() { + + if (TheLoop->isAnnotatedParallel()) { + DEBUG(dbgs() + << "LV: A loop annotated parallel, ignore memory dependency " + << "checks.\n"); + return true; + } + typedef SmallVector<Value*, 16> ValueVector; typedef SmallPtrSet<Value*, 16> ValueSet; // Holds the Load and Store *instructions*. @@ -1545,9 +2502,10 @@ bool LoopVectorizationLegality::canVectorizeMemory() { return true; } - // Holds the read and read-write *pointers* that we find. - ValueVector Reads; - ValueVector ReadWrites; + // Holds the read and read-write *pointers* that we find. These maps hold + // unique values for pointers (so no need for multi-map). + AliasMap Reads; + AliasMap ReadWrites; // Holds the analyzed pointers. We don't want to call GetUnderlyingObjects // multiple times on the same object. If the ptr is accessed twice, once @@ -1558,8 +2516,7 @@ bool LoopVectorizationLegality::canVectorizeMemory() { ValueVector::iterator I, IE; for (I = Stores.begin(), IE = Stores.end(); I != IE; ++I) { - StoreInst *ST = dyn_cast<StoreInst>(*I); - assert(ST && "Bad StoreInst"); + StoreInst *ST = cast<StoreInst>(*I); Value* Ptr = ST->getPointerOperand(); if (isUniform(Ptr)) { @@ -1570,12 +2527,11 @@ bool LoopVectorizationLegality::canVectorizeMemory() { // If we did *not* see this pointer before, insert it to // the read-write list. At this phase it is only a 'write' list. if (Seen.insert(Ptr)) - ReadWrites.push_back(Ptr); + ReadWrites.insert(std::make_pair(Ptr, ST)); } for (I = Loads.begin(), IE = Loads.end(); I != IE; ++I) { - LoadInst *LD = dyn_cast<LoadInst>(*I); - assert(LD && "Bad LoadInst"); + LoadInst *LD = cast<LoadInst>(*I); Value* Ptr = LD->getPointerOperand(); // If we did *not* see this pointer before, insert it to the // read list. If we *did* see it before, then it is already in @@ -1585,8 +2541,8 @@ bool LoopVectorizationLegality::canVectorizeMemory() { // If the address of i is unknown (for example A[B[i]]) then we may // read a few words, modify, and write a few words, and some of the // words may be written to the same address. - if (Seen.insert(Ptr) || !isConsecutivePtr(Ptr)) - Reads.push_back(Ptr); + if (Seen.insert(Ptr) || 0 == isConsecutivePtr(Ptr)) + Reads.insert(std::make_pair(Ptr, LD)); } // If we write (or read-write) to a single destination and there are no @@ -1598,83 +2554,156 @@ bool LoopVectorizationLegality::canVectorizeMemory() { // Find pointers with computable bounds. We are going to use this information // to place a runtime bound check. - bool RT = true; - for (I = ReadWrites.begin(), IE = ReadWrites.end(); I != IE; ++I) - if (hasComputableBounds(*I)) { - PtrRtCheck.insert(SE, TheLoop, *I); - DEBUG(dbgs() << "LV: Found a runtime check ptr:" << **I <<"\n"); + bool CanDoRT = true; + AliasMap::iterator MI, ME; + for (MI = ReadWrites.begin(), ME = ReadWrites.end(); MI != ME; ++MI) { + Value *V = (*MI).first; + if (hasComputableBounds(V)) { + PtrRtCheck.insert(SE, TheLoop, V); + DEBUG(dbgs() << "LV: Found a runtime check ptr:" << *V <<"\n"); } else { - RT = false; + CanDoRT = false; break; } - for (I = Reads.begin(), IE = Reads.end(); I != IE; ++I) - if (hasComputableBounds(*I)) { - PtrRtCheck.insert(SE, TheLoop, *I); - DEBUG(dbgs() << "LV: Found a runtime check ptr:" << **I <<"\n"); + } + for (MI = Reads.begin(), ME = Reads.end(); MI != ME; ++MI) { + Value *V = (*MI).first; + if (hasComputableBounds(V)) { + PtrRtCheck.insert(SE, TheLoop, V); + DEBUG(dbgs() << "LV: Found a runtime check ptr:" << *V <<"\n"); } else { - RT = false; + CanDoRT = false; break; } + } // Check that we did not collect too many pointers or found a // unsizeable pointer. - if (!RT || PtrRtCheck.Pointers.size() > RuntimeMemoryCheckThreshold) { + if (!CanDoRT || PtrRtCheck.Pointers.size() > RuntimeMemoryCheckThreshold) { PtrRtCheck.reset(); - RT = false; + CanDoRT = false; } - PtrRtCheck.Need = RT; - - if (RT) { + if (CanDoRT) { DEBUG(dbgs() << "LV: We can perform a memory runtime check if needed.\n"); } + bool NeedRTCheck = false; + + // Biggest vectorized access possible, vector width * unroll factor. + // TODO: We're being very pessimistic here, find a way to know the + // real access width before getting here. + unsigned MaxByteWidth = (TTI->getRegisterBitWidth(true) / 8) * + TTI->getMaximumUnrollFactor(); // Now that the pointers are in two lists (Reads and ReadWrites), we // can check that there are no conflicts between each of the writes and // between the writes to the reads. - ValueSet WriteObjects; + // Note that WriteObjects duplicates the stores (indexed now by underlying + // objects) to avoid pointing to elements inside ReadWrites. + // TODO: Maybe create a new type where they can interact without duplication. + AliasMultiMap WriteObjects; ValueVector TempObjects; // Check that the read-writes do not conflict with other read-write // pointers. - for (I = ReadWrites.begin(), IE = ReadWrites.end(); I != IE; ++I) { - GetUnderlyingObjects(*I, TempObjects, DL); - for (ValueVector::iterator it=TempObjects.begin(), e=TempObjects.end(); - it != e; ++it) { - if (!isIdentifiedObject(*it)) { - DEBUG(dbgs() << "LV: Found an unidentified write ptr:"<< **it <<"\n"); - return RT; + bool AllWritesIdentified = true; + for (MI = ReadWrites.begin(), ME = ReadWrites.end(); MI != ME; ++MI) { + Value *Val = (*MI).first; + Instruction *Inst = (*MI).second; + + GetUnderlyingObjects(Val, TempObjects, DL); + for (ValueVector::iterator UI=TempObjects.begin(), UE=TempObjects.end(); + UI != UE; ++UI) { + if (!isIdentifiedObject(*UI)) { + DEBUG(dbgs() << "LV: Found an unidentified write ptr:"<< **UI <<"\n"); + NeedRTCheck = true; + AllWritesIdentified = false; } - if (!WriteObjects.insert(*it)) { + + // Never seen it before, can't alias. + if (WriteObjects[*UI].empty()) { + DEBUG(dbgs() << "LV: Adding Underlying value:" << **UI <<"\n"); + WriteObjects[*UI].push_back(Inst); + continue; + } + // Direct alias found. + if (!AA || dyn_cast<GlobalValue>(*UI) == NULL) { DEBUG(dbgs() << "LV: Found a possible write-write reorder:" - << **it <<"\n"); - return RT; + << **UI <<"\n"); + return false; } + DEBUG(dbgs() << "LV: Found a conflicting global value:" + << **UI <<"\n"); + DEBUG(dbgs() << "LV: While examining store:" << *Inst <<"\n"); + DEBUG(dbgs() << "LV: On value:" << *Val <<"\n"); + + // If global alias, make sure they do alias. + if (hasPossibleGlobalWriteReorder(*UI, + Inst, + WriteObjects, + MaxByteWidth)) { + DEBUG(dbgs() << "LV: Found a possible write-write reorder:" + << *UI <<"\n"); + return false; + } + + // Didn't alias, insert into map for further reference. + WriteObjects[*UI].push_back(Inst); } TempObjects.clear(); } /// Check that the reads don't conflict with the read-writes. - for (I = Reads.begin(), IE = Reads.end(); I != IE; ++I) { - GetUnderlyingObjects(*I, TempObjects, DL); - for (ValueVector::iterator it=TempObjects.begin(), e=TempObjects.end(); - it != e; ++it) { - if (!isIdentifiedObject(*it)) { - DEBUG(dbgs() << "LV: Found an unidentified read ptr:"<< **it <<"\n"); - return RT; + for (MI = Reads.begin(), ME = Reads.end(); MI != ME; ++MI) { + Value *Val = (*MI).first; + GetUnderlyingObjects(Val, TempObjects, DL); + for (ValueVector::iterator UI=TempObjects.begin(), UE=TempObjects.end(); + UI != UE; ++UI) { + // If all of the writes are identified then we don't care if the read + // pointer is identified or not. + if (!AllWritesIdentified && !isIdentifiedObject(*UI)) { + DEBUG(dbgs() << "LV: Found an unidentified read ptr:"<< **UI <<"\n"); + NeedRTCheck = true; + } + + // Never seen it before, can't alias. + if (WriteObjects[*UI].empty()) + continue; + // Direct alias found. + if (!AA || dyn_cast<GlobalValue>(*UI) == NULL) { + DEBUG(dbgs() << "LV: Found a possible write-write reorder:" + << **UI <<"\n"); + return false; } - if (WriteObjects.count(*it)) { - DEBUG(dbgs() << "LV: Found a possible read/write reorder:" - << **it <<"\n"); - return RT; + DEBUG(dbgs() << "LV: Found a global value: " + << **UI <<"\n"); + Instruction *Inst = (*MI).second; + DEBUG(dbgs() << "LV: While examining load:" << *Inst <<"\n"); + DEBUG(dbgs() << "LV: On value:" << *Val <<"\n"); + + // If global alias, make sure they do alias. + if (hasPossibleGlobalWriteReorder(*UI, + Inst, + WriteObjects, + MaxByteWidth)) { + DEBUG(dbgs() << "LV: Found a possible read-write reorder:" + << *UI <<"\n"); + return false; } } TempObjects.clear(); } - // It is safe to vectorize and we don't need any runtime checks. - DEBUG(dbgs() << "LV: We don't need a runtime memory check.\n"); - PtrRtCheck.reset(); + PtrRtCheck.Need = NeedRTCheck; + if (NeedRTCheck && !CanDoRT) { + DEBUG(dbgs() << "LV: We can't vectorize because we can't find " << + "the array bounds.\n"); + PtrRtCheck.reset(); + return false; + } + + DEBUG(dbgs() << "LV: We "<< (NeedRTCheck ? "" : "don't") << + " need a runtime memory check.\n"); return true; } @@ -1696,12 +2725,13 @@ bool LoopVectorizationLegality::AddReductionVar(PHINode *Phi, // This includes users of the reduction, variables (which form a cycle // which ends in the phi node). Instruction *ExitInstruction = 0; + // Indicates that we found a binary operation in our scan. + bool FoundBinOp = false; // Iter is our iterator. We start with the PHI node and scan for all of the - // users of this instruction. All users must be instructions which can be + // users of this instruction. All users must be instructions that can be // used as reduction variables (such as ADD). We may have a single - // out-of-block user. They cycle must end with the original PHI. - // Also, we can't have multiple block-local users. + // out-of-block user. The cycle must end with the original PHI. Instruction *Iter = Phi; while (true) { // If the instruction has no users then this is a broken @@ -1709,15 +2739,17 @@ bool LoopVectorizationLegality::AddReductionVar(PHINode *Phi, if (Iter->use_empty()) return false; - // Any reduction instr must be of one of the allowed kinds. - if (!isReductionInstr(Iter, Kind)) - return false; - - // Did we find a user inside this block ? + // Did we find a user inside this loop already ? bool FoundInBlockUser = false; - // Did we reach the initial PHI node ? + // Did we reach the initial PHI node already ? bool FoundStartPHI = false; + // Is this a bin op ? + FoundBinOp |= !isa<PHINode>(Iter); + + // Remember the current instruction. + Instruction *OldIter = Iter; + // For each of the *users* of iter. for (Value::use_iterator it = Iter->use_begin(), e = Iter->use_end(); it != e; ++it) { @@ -1740,58 +2772,82 @@ bool LoopVectorizationLegality::AddReductionVar(PHINode *Phi, // We allow in-loop PHINodes which are not the original reduction PHI // node. If this PHI is the only user of Iter (happens in IF w/ no ELSE // structure) then don't skip this PHI. - if (isa<PHINode>(U) && U->getParent() != TheLoop->getHeader() && - TheLoop->contains(U) && Iter->getNumUses() > 1) + if (isa<PHINode>(Iter) && isa<PHINode>(U) && + U->getParent() != TheLoop->getHeader() && + TheLoop->contains(U) && + Iter->hasNUsesOrMore(2)) continue; // We can't have multiple inside users. if (FoundInBlockUser) return false; FoundInBlockUser = true; + + // Any reduction instr must be of one of the allowed kinds. + if (!isReductionInstr(U, Kind)) + return false; + + // Reductions of instructions such as Div, and Sub is only + // possible if the LHS is the reduction variable. + if (!U->isCommutative() && !isa<PHINode>(U) && U->getOperand(0) != Iter) + return false; + Iter = U; } + // If all uses were skipped this can't be a reduction variable. + if (Iter == OldIter) + return false; + // We found a reduction var if we have reached the original // phi node and we only have a single instruction with out-of-loop // users. - if (FoundStartPHI && ExitInstruction) { + if (FoundStartPHI) { // This instruction is allowed to have out-of-loop users. AllowedExit.insert(ExitInstruction); // Save the description of this reduction variable. ReductionDescriptor RD(RdxStart, ExitInstruction, Kind); Reductions[Phi] = RD; - return true; + // We've ended the cycle. This is a reduction variable if we have an + // outside user and it has a binary op. + return FoundBinOp && ExitInstruction; } - - // If we've reached the start PHI but did not find an outside user then - // this is dead code. Abort. - if (FoundStartPHI) - return false; } } bool LoopVectorizationLegality::isReductionInstr(Instruction *I, ReductionKind Kind) { + bool FP = I->getType()->isFloatingPointTy(); + bool FastMath = (FP && I->isCommutative() && I->isAssociative()); + switch (I->getOpcode()) { default: return false; case Instruction::PHI: + if (FP && (Kind != RK_FloatMult && Kind != RK_FloatAdd)) + return false; // possibly. return true; - case Instruction::Add: case Instruction::Sub: - return Kind == IntegerAdd; + case Instruction::Add: + return Kind == RK_IntegerAdd; + case Instruction::SDiv: + case Instruction::UDiv: case Instruction::Mul: - return Kind == IntegerMult; + return Kind == RK_IntegerMult; case Instruction::And: - return Kind == IntegerAnd; + return Kind == RK_IntegerAnd; case Instruction::Or: - return Kind == IntegerOr; + return Kind == RK_IntegerOr; case Instruction::Xor: - return Kind == IntegerXor; - } + return Kind == RK_IntegerXor; + case Instruction::FMul: + return Kind == RK_FloatMult && FastMath; + case Instruction::FAdd: + return Kind == RK_FloatAdd && FastMath; + } } LoopVectorizationLegality::InductionKind @@ -1799,37 +2855,48 @@ LoopVectorizationLegality::isInductionVariable(PHINode *Phi) { Type *PhiTy = Phi->getType(); // We only handle integer and pointer inductions variables. if (!PhiTy->isIntegerTy() && !PhiTy->isPointerTy()) - return NoInduction; + return IK_NoInduction; - // Check that the PHI is consecutive and starts at zero. + // Check that the PHI is consecutive. const SCEV *PhiScev = SE->getSCEV(Phi); const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PhiScev); if (!AR) { DEBUG(dbgs() << "LV: PHI is not a poly recurrence.\n"); - return NoInduction; + return IK_NoInduction; } const SCEV *Step = AR->getStepRecurrence(*SE); // Integer inductions need to have a stride of one. if (PhiTy->isIntegerTy()) { if (Step->isOne()) - return IntInduction; + return IK_IntInduction; if (Step->isAllOnesValue()) - return ReverseIntInduction; - return NoInduction; + return IK_ReverseIntInduction; + return IK_NoInduction; } // Calculate the pointer stride and check if it is consecutive. const SCEVConstant *C = dyn_cast<SCEVConstant>(Step); if (!C) - return NoInduction; + return IK_NoInduction; assert(PhiTy->isPointerTy() && "The PHI must be a pointer"); uint64_t Size = DL->getTypeAllocSize(PhiTy->getPointerElementType()); if (C->getValue()->equalsInt(Size)) - return PtrInduction; + return IK_PtrInduction; + else if (C->getValue()->equalsInt(0 - Size)) + return IK_ReversePtrInduction; + + return IK_NoInduction; +} + +bool LoopVectorizationLegality::isInductionVariable(const Value *V) { + Value *In0 = const_cast<Value*>(V); + PHINode *PN = dyn_cast_or_null<PHINode>(In0); + if (!PN) + return false; - return NoInduction; + return Inductions.count(PN); } bool LoopVectorizationLegality::blockNeedsPredication(BasicBlock *BB) { @@ -1846,7 +2913,7 @@ bool LoopVectorizationLegality::blockCanBePredicated(BasicBlock *BB) { if (it->mayReadFromMemory() || it->mayWriteToMemory() || it->mayThrow()) return false; - // The isntructions below can trap. + // The instructions below can trap. switch (it->getOpcode()) { default: continue; case Instruction::UDiv: @@ -1869,11 +2936,64 @@ bool LoopVectorizationLegality::hasComputableBounds(Value *Ptr) { return AR->isAffine(); } -unsigned -LoopVectorizationCostModel::findBestVectorizationFactor(unsigned VF) { - if (!VTTI) { - DEBUG(dbgs() << "LV: No vector target information. Not vectorizing. \n"); - return 1; +LoopVectorizationCostModel::VectorizationFactor +LoopVectorizationCostModel::selectVectorizationFactor(bool OptForSize, + unsigned UserVF) { + // Width 1 means no vectorize + VectorizationFactor Factor = { 1U, 0U }; + if (OptForSize && Legal->getRuntimePointerCheck()->Need) { + DEBUG(dbgs() << "LV: Aborting. Runtime ptr check is required in Os.\n"); + return Factor; + } + + // Find the trip count. + unsigned TC = SE->getSmallConstantTripCount(TheLoop, TheLoop->getLoopLatch()); + DEBUG(dbgs() << "LV: Found trip count:"<<TC<<"\n"); + + unsigned WidestType = getWidestType(); + unsigned WidestRegister = TTI.getRegisterBitWidth(true); + unsigned MaxVectorSize = WidestRegister / WidestType; + DEBUG(dbgs() << "LV: The Widest type: " << WidestType << " bits.\n"); + DEBUG(dbgs() << "LV: The Widest register is:" << WidestRegister << "bits.\n"); + + if (MaxVectorSize == 0) { + DEBUG(dbgs() << "LV: The target has no vector registers.\n"); + MaxVectorSize = 1; + } + + assert(MaxVectorSize <= 32 && "Did not expect to pack so many elements" + " into one vector!"); + + unsigned VF = MaxVectorSize; + + // If we optimize the program for size, avoid creating the tail loop. + if (OptForSize) { + // If we are unable to calculate the trip count then don't try to vectorize. + if (TC < 2) { + DEBUG(dbgs() << "LV: Aborting. A tail loop is required in Os.\n"); + return Factor; + } + + // Find the maximum SIMD width that can fit within the trip count. + VF = TC % MaxVectorSize; + + if (VF == 0) + VF = MaxVectorSize; + + // If the trip count that we found modulo the vectorization factor is not + // zero then we require a tail. + if (VF < 2) { + DEBUG(dbgs() << "LV: Aborting. A tail loop is required in Os.\n"); + return Factor; + } + } + + if (UserVF != 0) { + assert(isPowerOf2_32(UserVF) && "VF needs to be a power of two"); + DEBUG(dbgs() << "LV: Using user VF "<<UserVF<<".\n"); + + Factor.Width = UserVF; + return Factor; } float Cost = expectedCost(1); @@ -1893,7 +3013,248 @@ LoopVectorizationCostModel::findBestVectorizationFactor(unsigned VF) { } DEBUG(dbgs() << "LV: Selecting VF = : "<< Width << ".\n"); - return Width; + Factor.Width = Width; + Factor.Cost = Width * Cost; + return Factor; +} + +unsigned LoopVectorizationCostModel::getWidestType() { + unsigned MaxWidth = 8; + + // For each block. + for (Loop::block_iterator bb = TheLoop->block_begin(), + be = TheLoop->block_end(); bb != be; ++bb) { + BasicBlock *BB = *bb; + + // For each instruction in the loop. + for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { + Type *T = it->getType(); + + // Only examine Loads, Stores and PHINodes. + if (!isa<LoadInst>(it) && !isa<StoreInst>(it) && !isa<PHINode>(it)) + continue; + + // Examine PHI nodes that are reduction variables. + if (PHINode *PN = dyn_cast<PHINode>(it)) + if (!Legal->getReductionVars()->count(PN)) + continue; + + // Examine the stored values. + if (StoreInst *ST = dyn_cast<StoreInst>(it)) + T = ST->getValueOperand()->getType(); + + // Ignore loaded pointer types and stored pointer types that are not + // consecutive. However, we do want to take consecutive stores/loads of + // pointer vectors into account. + if (T->isPointerTy() && !isConsecutiveLoadOrStore(it)) + continue; + + MaxWidth = std::max(MaxWidth, + (unsigned)DL->getTypeSizeInBits(T->getScalarType())); + } + } + + return MaxWidth; +} + +unsigned +LoopVectorizationCostModel::selectUnrollFactor(bool OptForSize, + unsigned UserUF, + unsigned VF, + unsigned LoopCost) { + + // -- The unroll heuristics -- + // We unroll the loop in order to expose ILP and reduce the loop overhead. + // There are many micro-architectural considerations that we can't predict + // at this level. For example frontend pressure (on decode or fetch) due to + // code size, or the number and capabilities of the execution ports. + // + // We use the following heuristics to select the unroll factor: + // 1. If the code has reductions the we unroll in order to break the cross + // iteration dependency. + // 2. If the loop is really small then we unroll in order to reduce the loop + // overhead. + // 3. We don't unroll if we think that we will spill registers to memory due + // to the increased register pressure. + + // Use the user preference, unless 'auto' is selected. + if (UserUF != 0) + return UserUF; + + // When we optimize for size we don't unroll. + if (OptForSize) + return 1; + + // Do not unroll loops with a relatively small trip count. + unsigned TC = SE->getSmallConstantTripCount(TheLoop, + TheLoop->getLoopLatch()); + if (TC > 1 && TC < TinyTripCountUnrollThreshold) + return 1; + + unsigned TargetVectorRegisters = TTI.getNumberOfRegisters(true); + DEBUG(dbgs() << "LV: The target has " << TargetVectorRegisters << + " vector registers\n"); + + LoopVectorizationCostModel::RegisterUsage R = calculateRegisterUsage(); + // We divide by these constants so assume that we have at least one + // instruction that uses at least one register. + R.MaxLocalUsers = std::max(R.MaxLocalUsers, 1U); + R.NumInstructions = std::max(R.NumInstructions, 1U); + + // We calculate the unroll factor using the following formula. + // Subtract the number of loop invariants from the number of available + // registers. These registers are used by all of the unrolled instances. + // Next, divide the remaining registers by the number of registers that is + // required by the loop, in order to estimate how many parallel instances + // fit without causing spills. + unsigned UF = (TargetVectorRegisters - R.LoopInvariantRegs) / R.MaxLocalUsers; + + // Clamp the unroll factor ranges to reasonable factors. + unsigned MaxUnrollSize = TTI.getMaximumUnrollFactor(); + + // If we did not calculate the cost for VF (because the user selected the VF) + // then we calculate the cost of VF here. + if (LoopCost == 0) + LoopCost = expectedCost(VF); + + // Clamp the calculated UF to be between the 1 and the max unroll factor + // that the target allows. + if (UF > MaxUnrollSize) + UF = MaxUnrollSize; + else if (UF < 1) + UF = 1; + + if (Legal->getReductionVars()->size()) { + DEBUG(dbgs() << "LV: Unrolling because of reductions. \n"); + return UF; + } + + // We want to unroll tiny loops in order to reduce the loop overhead. + // We assume that the cost overhead is 1 and we use the cost model + // to estimate the cost of the loop and unroll until the cost of the + // loop overhead is about 5% of the cost of the loop. + DEBUG(dbgs() << "LV: Loop cost is "<< LoopCost <<" \n"); + if (LoopCost < 20) { + DEBUG(dbgs() << "LV: Unrolling to reduce branch cost. \n"); + unsigned NewUF = 20/LoopCost + 1; + return std::min(NewUF, UF); + } + + DEBUG(dbgs() << "LV: Not Unrolling. \n"); + return 1; +} + +LoopVectorizationCostModel::RegisterUsage +LoopVectorizationCostModel::calculateRegisterUsage() { + // This function calculates the register usage by measuring the highest number + // of values that are alive at a single location. Obviously, this is a very + // rough estimation. We scan the loop in a topological order in order and + // assign a number to each instruction. We use RPO to ensure that defs are + // met before their users. We assume that each instruction that has in-loop + // users starts an interval. We record every time that an in-loop value is + // used, so we have a list of the first and last occurrences of each + // instruction. Next, we transpose this data structure into a multi map that + // holds the list of intervals that *end* at a specific location. This multi + // map allows us to perform a linear search. We scan the instructions linearly + // and record each time that a new interval starts, by placing it in a set. + // If we find this value in the multi-map then we remove it from the set. + // The max register usage is the maximum size of the set. + // We also search for instructions that are defined outside the loop, but are + // used inside the loop. We need this number separately from the max-interval + // usage number because when we unroll, loop-invariant values do not take + // more register. + LoopBlocksDFS DFS(TheLoop); + DFS.perform(LI); + + RegisterUsage R; + R.NumInstructions = 0; + + // Each 'key' in the map opens a new interval. The values + // of the map are the index of the 'last seen' usage of the + // instruction that is the key. + typedef DenseMap<Instruction*, unsigned> IntervalMap; + // Maps instruction to its index. + DenseMap<unsigned, Instruction*> IdxToInstr; + // Marks the end of each interval. + IntervalMap EndPoint; + // Saves the list of instruction indices that are used in the loop. + SmallSet<Instruction*, 8> Ends; + // Saves the list of values that are used in the loop but are + // defined outside the loop, such as arguments and constants. + SmallPtrSet<Value*, 8> LoopInvariants; + + unsigned Index = 0; + for (LoopBlocksDFS::RPOIterator bb = DFS.beginRPO(), + be = DFS.endRPO(); bb != be; ++bb) { + R.NumInstructions += (*bb)->size(); + for (BasicBlock::iterator it = (*bb)->begin(), e = (*bb)->end(); it != e; + ++it) { + Instruction *I = it; + IdxToInstr[Index++] = I; + + // Save the end location of each USE. + for (unsigned i = 0; i < I->getNumOperands(); ++i) { + Value *U = I->getOperand(i); + Instruction *Instr = dyn_cast<Instruction>(U); + + // Ignore non-instruction values such as arguments, constants, etc. + if (!Instr) continue; + + // If this instruction is outside the loop then record it and continue. + if (!TheLoop->contains(Instr)) { + LoopInvariants.insert(Instr); + continue; + } + + // Overwrite previous end points. + EndPoint[Instr] = Index; + Ends.insert(Instr); + } + } + } + + // Saves the list of intervals that end with the index in 'key'. + typedef SmallVector<Instruction*, 2> InstrList; + DenseMap<unsigned, InstrList> TransposeEnds; + + // Transpose the EndPoints to a list of values that end at each index. + for (IntervalMap::iterator it = EndPoint.begin(), e = EndPoint.end(); + it != e; ++it) + TransposeEnds[it->second].push_back(it->first); + + SmallSet<Instruction*, 8> OpenIntervals; + unsigned MaxUsage = 0; + + + DEBUG(dbgs() << "LV(REG): Calculating max register usage:\n"); + for (unsigned int i = 0; i < Index; ++i) { + Instruction *I = IdxToInstr[i]; + // Ignore instructions that are never used within the loop. + if (!Ends.count(I)) continue; + + // Remove all of the instructions that end at this location. + InstrList &List = TransposeEnds[i]; + for (unsigned int j=0, e = List.size(); j < e; ++j) + OpenIntervals.erase(List[j]); + + // Count the number of live interals. + MaxUsage = std::max(MaxUsage, OpenIntervals.size()); + + DEBUG(dbgs() << "LV(REG): At #" << i << " Interval # " << + OpenIntervals.size() <<"\n"); + + // Add the current instruction to the list of open intervals. + OpenIntervals.insert(I); + } + + unsigned Invariant = LoopInvariants.size(); + DEBUG(dbgs() << "LV(REG): Found max usage: " << MaxUsage << " \n"); + DEBUG(dbgs() << "LV(REG): Found invariant usage: " << Invariant << " \n"); + DEBUG(dbgs() << "LV(REG): LoopSize: " << R.NumInstructions << " \n"); + + R.LoopInvariantRegs = Invariant; + R.MaxLocalUsers = MaxUsage; + return R; } unsigned LoopVectorizationCostModel::expectedCost(unsigned VF) { @@ -1907,6 +3268,10 @@ unsigned LoopVectorizationCostModel::expectedCost(unsigned VF) { // For each instruction in the old loop. for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { + // Skip dbg intrinsics. + if (isa<DbgInfoIntrinsic>(it)) + continue; + unsigned C = getInstructionCost(it, VF); Cost += C; DEBUG(dbgs() << "LV: Found an estimated cost of "<< C <<" for VF " << @@ -1927,8 +3292,6 @@ unsigned LoopVectorizationCostModel::expectedCost(unsigned VF) { unsigned LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { - assert(VTTI && "Invalid vector target transformation info"); - // If we know that this instruction will remain uniform, check the cost of // the scalar version. if (Legal->isUniformAfterVectorization(I)) @@ -1940,12 +3303,13 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { // TODO: We need to estimate the cost of intrinsic calls. switch (I->getOpcode()) { 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. + // We mark this instruction as zero-cost because the cost of GEPs in + // vectorized code depends on whether the corresponding memory instruction + // is scalarized or not. Therefore, we handle GEPs with the memory + // instruction cost. return 0; case Instruction::Br: { - return VTTI->getCFInstrCost(I->getOpcode()); + return TTI.getCFInstrCost(I->getOpcode()); } case Instruction::PHI: //TODO: IF-converted IFs become selects. @@ -1968,7 +3332,7 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { case Instruction::And: case Instruction::Or: case Instruction::Xor: - return VTTI->getArithmeticInstrCost(I->getOpcode(), VectorTy); + return TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy); case Instruction::Select: { SelectInst *SI = cast<SelectInst>(I); const SCEV *CondSCEV = SE->getSCEV(SI->getCondition()); @@ -1977,68 +3341,66 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { if (ScalarCond) CondTy = VectorType::get(CondTy, VF); - return VTTI->getCmpSelInstrCost(I->getOpcode(), VectorTy, CondTy); + return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy, CondTy); } case Instruction::ICmp: case Instruction::FCmp: { Type *ValTy = I->getOperand(0)->getType(); VectorTy = ToVectorTy(ValTy, VF); - return VTTI->getCmpSelInstrCost(I->getOpcode(), VectorTy); + return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy); } - case Instruction::Store: { - StoreInst *SI = cast<StoreInst>(I); - Type *ValTy = SI->getValueOperand()->getType(); + case Instruction::Store: + case Instruction::Load: { + StoreInst *SI = dyn_cast<StoreInst>(I); + LoadInst *LI = dyn_cast<LoadInst>(I); + Type *ValTy = (SI ? SI->getValueOperand()->getType() : + LI->getType()); VectorTy = ToVectorTy(ValTy, VF); + unsigned Alignment = SI ? SI->getAlignment() : LI->getAlignment(); + unsigned AS = SI ? SI->getPointerAddressSpace() : + LI->getPointerAddressSpace(); + Value *Ptr = SI ? SI->getPointerOperand() : LI->getPointerOperand(); + // We add the cost of address computation here instead of with the gep + // instruction because only here we know whether the operation is + // scalarized. if (VF == 1) - return VTTI->getMemoryOpCost(I->getOpcode(), ValTy, - SI->getAlignment(), - SI->getPointerAddressSpace()); + return TTI.getAddressComputationCost(VectorTy) + + TTI.getMemoryOpCost(I->getOpcode(), VectorTy, Alignment, AS); - // Scalarized stores. - if (!Legal->isConsecutivePtr(SI->getPointerOperand())) { + // Scalarized loads/stores. + int Stride = Legal->isConsecutivePtr(Ptr); + bool Reverse = Stride < 0; + if (0 == Stride) { unsigned Cost = 0; - unsigned ExtCost = VTTI->getInstrCost(Instruction::ExtractElement, - ValTy); - // The cost of extracting from the value vector. - Cost += VF * (ExtCost); - // The cost of the scalar stores. - Cost += VF * VTTI->getMemoryOpCost(I->getOpcode(), - ValTy->getScalarType(), - SI->getAlignment(), - SI->getPointerAddressSpace()); - return Cost; - } - - // Wide stores. - return VTTI->getMemoryOpCost(I->getOpcode(), VectorTy, SI->getAlignment(), - SI->getPointerAddressSpace()); - } - case Instruction::Load: { - LoadInst *LI = cast<LoadInst>(I); - - if (VF == 1) - return VTTI->getMemoryOpCost(I->getOpcode(), RetTy, - LI->getAlignment(), - LI->getPointerAddressSpace()); + // The cost of extracting from the value vector and pointer vector. + Type *PtrTy = ToVectorTy(Ptr->getType(), VF); + for (unsigned i = 0; i < VF; ++i) { + // The cost of extracting the pointer operand. + Cost += TTI.getVectorInstrCost(Instruction::ExtractElement, PtrTy, i); + // In case of STORE, the cost of ExtractElement from the vector. + // In case of LOAD, the cost of InsertElement into the returned + // vector. + Cost += TTI.getVectorInstrCost(SI ? Instruction::ExtractElement : + Instruction::InsertElement, + VectorTy, i); + } - // Scalarized loads. - if (!Legal->isConsecutivePtr(LI->getPointerOperand())) { - unsigned Cost = 0; - unsigned InCost = VTTI->getInstrCost(Instruction::InsertElement, RetTy); - // The cost of inserting the loaded value into the result vector. - Cost += VF * (InCost); - // The cost of the scalar stores. - Cost += VF * VTTI->getMemoryOpCost(I->getOpcode(), - RetTy->getScalarType(), - LI->getAlignment(), - LI->getPointerAddressSpace()); + // The cost of the scalar loads/stores. + Cost += VF * TTI.getAddressComputationCost(ValTy->getScalarType()); + Cost += VF * TTI.getMemoryOpCost(I->getOpcode(), ValTy->getScalarType(), + Alignment, AS); return Cost; } - // Wide loads. - return VTTI->getMemoryOpCost(I->getOpcode(), VectorTy, LI->getAlignment(), - LI->getPointerAddressSpace()); + // Wide load/stores. + unsigned Cost = TTI.getAddressComputationCost(VectorTy); + Cost += TTI.getMemoryOpCost(I->getOpcode(), VectorTy, Alignment, AS); + + if (Reverse) + Cost += TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, + VectorTy, 0); + return Cost; } case Instruction::ZExt: case Instruction::SExt: @@ -2052,17 +3414,25 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { case Instruction::Trunc: case Instruction::FPTrunc: case Instruction::BitCast: { + // We optimize the truncation of induction variable. + // The cost of these is the same as the scalar operation. + if (I->getOpcode() == Instruction::Trunc && + Legal->isInductionVariable(I->getOperand(0))) + return TTI.getCastInstrCost(I->getOpcode(), I->getType(), + I->getOperand(0)->getType()); + Type *SrcVecTy = ToVectorTy(I->getOperand(0)->getType(), VF); - return VTTI->getCastInstrCost(I->getOpcode(), VectorTy, SrcVecTy); + return TTI.getCastInstrCost(I->getOpcode(), VectorTy, SrcVecTy); } case Instruction::Call: { - assert(isTriviallyVectorizableIntrinsic(I)); - IntrinsicInst *II = cast<IntrinsicInst>(I); - Type *RetTy = ToVectorTy(II->getType(), VF); + CallInst *CI = cast<CallInst>(I); + Intrinsic::ID ID = getIntrinsicIDForCall(CI, TLI); + assert(ID && "Not an intrinsic call!"); + Type *RetTy = ToVectorTy(CI->getType(), VF); SmallVector<Type*, 4> Tys; - for (unsigned i = 0, ie = II->getNumArgOperands(); i != ie; ++i) - Tys.push_back(ToVectorTy(II->getArgOperand(i)->getType(), VF)); - return VTTI->getIntrinsicInstrCost(II->getIntrinsicID(), RetTy, Tys); + for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) + Tys.push_back(ToVectorTy(CI->getArgOperand(i)->getType(), VF)); + return TTI.getIntrinsicInstrCost(ID, RetTy, Tys); } default: { // We are scalarizing the instruction. Return the cost of the scalar @@ -2070,21 +3440,20 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { // elements, times the vector width. unsigned Cost = 0; - bool IsVoid = RetTy->isVoidTy(); - - unsigned InsCost = (IsVoid ? 0 : - VTTI->getInstrCost(Instruction::InsertElement, - VectorTy)); + if (!RetTy->isVoidTy() && VF != 1) { + unsigned InsCost = TTI.getVectorInstrCost(Instruction::InsertElement, + VectorTy); + unsigned ExtCost = TTI.getVectorInstrCost(Instruction::ExtractElement, + VectorTy); - unsigned ExtCost = VTTI->getInstrCost(Instruction::ExtractElement, - VectorTy); - - // The cost of inserting the results plus extracting each one of the - // operands. - Cost += VF * (InsCost + ExtCost * I->getNumOperands()); + // The cost of inserting the results plus extracting each one of the + // operands. + Cost += VF * (InsCost + ExtCost * I->getNumOperands()); + } - // The cost of executing VF copies of the scalar instruction. - Cost += VF * VTTI->getInstrCost(I->getOpcode(), RetTy); + // The cost of executing VF copies of the scalar instruction. This opcode + // is unknown. Assume that it is the same as 'mul'. + Cost += VF * TTI.getArithmeticInstrCost(Instruction::Mul, VectorTy); return Cost; } }// end of switch. @@ -2100,6 +3469,7 @@ char LoopVectorize::ID = 0; static const char lv_name[] = "Loop Vectorization"; INITIALIZE_PASS_BEGIN(LoopVectorize, LV_NAME, lv_name, false, false) INITIALIZE_AG_DEPENDENCY(AliasAnalysis) +INITIALIZE_AG_DEPENDENCY(TargetTransformInfo) INITIALIZE_PASS_DEPENDENCY(ScalarEvolution) INITIALIZE_PASS_DEPENDENCY(LoopSimplify) INITIALIZE_PASS_END(LoopVectorize, LV_NAME, lv_name, false, false) @@ -2110,4 +3480,14 @@ namespace llvm { } } +bool LoopVectorizationCostModel::isConsecutiveLoadOrStore(Instruction *Inst) { + // Check for a store. + if (StoreInst *ST = dyn_cast<StoreInst>(Inst)) + return Legal->isConsecutivePtr(ST->getPointerOperand()) != 0; + + // Check for a load. + if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) + return Legal->isConsecutivePtr(LI->getPointerOperand()) != 0; + return false; +} diff --git a/lib/Transforms/Vectorize/LoopVectorize.h b/lib/Transforms/Vectorize/LoopVectorize.h deleted file mode 100644 index 9d6d80e22b..0000000000 --- a/lib/Transforms/Vectorize/LoopVectorize.h +++ /dev/null @@ -1,458 +0,0 @@ -//===- LoopVectorize.h --- A Loop Vectorizer ------------------------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This is the LLVM loop vectorizer. This pass modifies 'vectorizable' loops -// and generates target-independent LLVM-IR. Legalization of the IR is done -// in the codegen. However, the vectorizes uses (will use) the codegen -// interfaces to generate IR that is likely to result in an optimal binary. -// -// The loop vectorizer combines consecutive loop iteration into a single -// 'wide' iteration. After this transformation the index is incremented -// by the SIMD vector width, and not by one. -// -// This pass has three parts: -// 1. The main loop pass that drives the different parts. -// 2. LoopVectorizationLegality - A unit that checks for the legality -// of the vectorization. -// 3. InnerLoopVectorizer - A unit that performs the actual -// widening of instructions. -// 4. LoopVectorizationCostModel - A unit that checks for the profitability -// of vectorization. It decides on the optimal vector width, which -// can be one, if vectorization is not profitable. -// -//===----------------------------------------------------------------------===// -// -// The reduction-variable vectorization is based on the paper: -// D. Nuzman and R. Henderson. Multi-platform Auto-vectorization. -// -// Variable uniformity checks are inspired by: -// Karrenberg, R. and Hack, S. Whole Function Vectorization. -// -// Other ideas/concepts are from: -// A. Zaks and D. Nuzman. Autovectorization in GCC-two years later. -// -// S. Maleki, Y. Gao, M. Garzaran, T. Wong and D. Padua. An Evaluation of -// Vectorizing Compilers. -// -//===----------------------------------------------------------------------===// -#ifndef LLVM_TRANSFORM_VECTORIZE_LOOP_VECTORIZE_H -#define LLVM_TRANSFORM_VECTORIZE_LOOP_VECTORIZE_H - -#define LV_NAME "loop-vectorize" -#define DEBUG_TYPE LV_NAME - -#include "llvm/Analysis/ScalarEvolution.h" -#include "llvm/ADT/SmallVector.h" -#include "llvm/ADT/DenseMap.h" -#include "llvm/ADT/SmallPtrSet.h" -#include "llvm/IRBuilder.h" - -#include <algorithm> -using namespace llvm; - -/// We don't vectorize loops with a known constant trip count below this number. -const unsigned TinyTripCountThreshold = 16; - -/// When performing a runtime memory check, do not check more than this -/// number of pointers. Notice that the check is quadratic! -const unsigned RuntimeMemoryCheckThreshold = 4; - -/// This is the highest vector width that we try to generate. -const unsigned MaxVectorSize = 8; - -namespace llvm { - -// Forward declarations. -class LoopVectorizationLegality; -class LoopVectorizationCostModel; -class VectorTargetTransformInfo; - -/// InnerLoopVectorizer vectorizes loops which contain only one basic -/// block to a specified vectorization factor (VF). -/// This class performs the widening of scalars into vectors, or multiple -/// scalars. This class also implements the following features: -/// * It inserts an epilogue loop for handling loops that don't have iteration -/// counts that are known to be a multiple of the vectorization factor. -/// * It handles the code generation for reduction variables. -/// * Scalarization (implementation using scalars) of un-vectorizable -/// instructions. -/// InnerLoopVectorizer does not perform any vectorization-legality -/// checks, and relies on the caller to check for the different legality -/// aspects. The InnerLoopVectorizer relies on the -/// LoopVectorizationLegality class to provide information about the induction -/// and reduction variables that were found to a given vectorization factor. -class InnerLoopVectorizer { -public: - /// Ctor. - InnerLoopVectorizer(Loop *Orig, ScalarEvolution *Se, LoopInfo *Li, - DominatorTree *Dt, DataLayout *Dl, unsigned VecWidth): - OrigLoop(Orig), SE(Se), LI(Li), DT(Dt), DL(Dl), VF(VecWidth), - Builder(Se->getContext()), Induction(0), OldInduction(0) { } - - // Perform the actual loop widening (vectorization). - void vectorize(LoopVectorizationLegality *Legal) { - // Create a new empty loop. Unlink the old loop and connect the new one. - createEmptyLoop(Legal); - // Widen each instruction in the old loop to a new one in the new loop. - // Use the Legality module to find the induction and reduction variables. - vectorizeLoop(Legal); - // Register the new loop and update the analysis passes. - updateAnalysis(); - } - -private: - /// A small list of PHINodes. - typedef SmallVector<PHINode*, 4> PhiVector; - - /// Add code that checks at runtime if the accessed arrays overlap. - /// Returns the comparator value or NULL if no check is needed. - Value *addRuntimeCheck(LoopVectorizationLegality *Legal, - Instruction *Loc); - /// Create an empty loop, based on the loop ranges of the old loop. - void createEmptyLoop(LoopVectorizationLegality *Legal); - /// Copy and widen the instructions from the old loop. - void vectorizeLoop(LoopVectorizationLegality *Legal); - - /// A helper function that computes the predicate of the block BB, assuming - /// that the header block of the loop is set to True. It returns the *entry* - /// mask for the block BB. - Value *createBlockInMask(BasicBlock *BB); - /// A helper function that computes the predicate of the edge between SRC - /// and DST. - Value *createEdgeMask(BasicBlock *Src, BasicBlock *Dst); - - /// A helper function to vectorize a single BB within the innermost loop. - void vectorizeBlockInLoop(LoopVectorizationLegality *Legal, BasicBlock *BB, - PhiVector *PV); - - /// Insert the new loop to the loop hierarchy and pass manager - /// and update the analysis passes. - void updateAnalysis(); - - /// This instruction is un-vectorizable. Implement it as a sequence - /// of scalars. - void scalarizeInstruction(Instruction *Instr); - - /// Create a broadcast instruction. This method generates a broadcast - /// instruction (shuffle) for loop invariant values and for the induction - /// value. If this is the induction variable then we extend it to N, N+1, ... - /// this is needed because each iteration in the loop corresponds to a SIMD - /// element. - Value *getBroadcastInstrs(Value *V); - - /// This function adds 0, 1, 2 ... to each vector element, starting at zero. - /// If Negate is set then negative numbers are added e.g. (0, -1, -2, ...). - Value *getConsecutiveVector(Value* Val, bool Negate = false); - - /// When we go over instructions in the basic block we rely on previous - /// values within the current basic block or on loop invariant values. - /// When we widen (vectorize) values we place them in the map. If the values - /// are not within the map, they have to be loop invariant, so we simply - /// broadcast them into a vector. - Value *getVectorValue(Value *V); - - /// Get a uniform vector of constant integers. We use this to get - /// vectors of ones and zeros for the reduction code. - Constant* getUniformVector(unsigned Val, Type* ScalarTy); - - typedef DenseMap<Value*, Value*> ValueMap; - - /// The original loop. - Loop *OrigLoop; - // Scev analysis to use. - ScalarEvolution *SE; - // Loop Info. - LoopInfo *LI; - // Dominator Tree. - DominatorTree *DT; - // Data Layout. - DataLayout *DL; - // The vectorization factor to use. - unsigned VF; - - // The builder that we use - IRBuilder<> Builder; - - // --- Vectorization state --- - - /// The vector-loop preheader. - BasicBlock *LoopVectorPreHeader; - /// The scalar-loop preheader. - BasicBlock *LoopScalarPreHeader; - /// Middle Block between the vector and the scalar. - BasicBlock *LoopMiddleBlock; - ///The ExitBlock of the scalar loop. - BasicBlock *LoopExitBlock; - ///The vector loop body. - BasicBlock *LoopVectorBody; - ///The scalar loop body. - BasicBlock *LoopScalarBody; - ///The first bypass block. - BasicBlock *LoopBypassBlock; - - /// The new Induction variable which was added to the new block. - PHINode *Induction; - /// The induction variable of the old basic block. - PHINode *OldInduction; - // Maps scalars to widened vectors. - ValueMap WidenMap; -}; - -/// LoopVectorizationLegality checks if it is legal to vectorize a loop, and -/// to what vectorization factor. -/// This class does not look at the profitability of vectorization, only the -/// legality. This class has two main kinds of checks: -/// * Memory checks - The code in canVectorizeMemory checks if vectorization -/// will change the order of memory accesses in a way that will change the -/// correctness of the program. -/// * Scalars checks - The code in canVectorizeInstrs and canVectorizeMemory -/// checks for a number of different conditions, such as the availability of a -/// single induction variable, that all types are supported and vectorize-able, -/// etc. This code reflects the capabilities of InnerLoopVectorizer. -/// This class is also used by InnerLoopVectorizer for identifying -/// induction variable and the different reduction variables. -class LoopVectorizationLegality { -public: - LoopVectorizationLegality(Loop *Lp, ScalarEvolution *Se, DataLayout *Dl, - DominatorTree *Dt): - TheLoop(Lp), SE(Se), DL(Dl), DT(Dt), Induction(0) { } - - /// This enum represents the kinds of reductions that we support. - enum ReductionKind { - NoReduction, /// Not a reduction. - IntegerAdd, /// Sum of numbers. - IntegerMult, /// Product of numbers. - IntegerOr, /// Bitwise or logical OR of numbers. - IntegerAnd, /// Bitwise or logical AND of numbers. - IntegerXor /// Bitwise or logical XOR of numbers. - }; - - /// This enum represents the kinds of inductions that we support. - enum InductionKind { - NoInduction, /// Not an induction variable. - IntInduction, /// Integer induction variable. Step = 1. - ReverseIntInduction, /// Reverse int induction variable. Step = -1. - PtrInduction /// Pointer induction variable. Step = sizeof(elem). - }; - - /// This POD struct holds information about reduction variables. - struct ReductionDescriptor { - // Default C'tor - ReductionDescriptor(): - StartValue(0), LoopExitInstr(0), Kind(NoReduction) {} - - // C'tor. - ReductionDescriptor(Value *Start, Instruction *Exit, ReductionKind K): - StartValue(Start), LoopExitInstr(Exit), Kind(K) {} - - // The starting value of the reduction. - // It does not have to be zero! - Value *StartValue; - // The instruction who's value is used outside the loop. - Instruction *LoopExitInstr; - // The kind of the reduction. - ReductionKind Kind; - }; - - // This POD struct holds information about the memory runtime legality - // check that a group of pointers do not overlap. - struct RuntimePointerCheck { - RuntimePointerCheck(): Need(false) {} - - /// Reset the state of the pointer runtime information. - void reset() { - Need = false; - Pointers.clear(); - Starts.clear(); - Ends.clear(); - } - - /// Insert a pointer and calculate the start and end SCEVs. - void insert(ScalarEvolution *SE, Loop *Lp, Value *Ptr); - - /// This flag indicates if we need to add the runtime check. - bool Need; - /// Holds the pointers that we need to check. - SmallVector<Value*, 2> Pointers; - /// Holds the pointer value at the beginning of the loop. - SmallVector<const SCEV*, 2> Starts; - /// Holds the pointer value at the end of the loop. - SmallVector<const SCEV*, 2> Ends; - }; - - /// A POD for saving information about induction variables. - struct InductionInfo { - /// Ctors. - InductionInfo(Value *Start, InductionKind K): - StartValue(Start), IK(K) {}; - InductionInfo(): StartValue(0), IK(NoInduction) {}; - /// Start value. - Value *StartValue; - /// Induction kind. - InductionKind IK; - }; - - /// ReductionList contains the reduction descriptors for all - /// of the reductions that were found in the loop. - typedef DenseMap<PHINode*, ReductionDescriptor> ReductionList; - - /// InductionList saves induction variables and maps them to the - /// induction descriptor. - typedef DenseMap<PHINode*, InductionInfo> InductionList; - - /// Returns true if it is legal to vectorize this loop. - /// This does not mean that it is profitable to vectorize this - /// loop, only that it is legal to do so. - bool canVectorize(); - - /// Returns the Induction variable. - PHINode *getInduction() {return Induction;} - - /// Returns the reduction variables found in the loop. - ReductionList *getReductionVars() { return &Reductions; } - - /// Returns the induction variables found in the loop. - InductionList *getInductionVars() { return &Inductions; } - - /// Return true if the block BB needs to be predicated in order for the loop - /// to be vectorized. - bool blockNeedsPredication(BasicBlock *BB); - - /// Check if this pointer is consecutive when vectorizing. This happens - /// when the last index of the GEP is the induction variable, or that the - /// pointer itself is an induction variable. - /// This check allows us to vectorize A[idx] into a wide load/store. - bool isConsecutivePtr(Value *Ptr); - - /// Returns true if the value V is uniform within the loop. - bool isUniform(Value *V); - - /// Returns true if this instruction will remain scalar after vectorization. - bool isUniformAfterVectorization(Instruction* I) {return Uniforms.count(I);} - - /// Returns the information that we collected about runtime memory check. - RuntimePointerCheck *getRuntimePointerCheck() {return &PtrRtCheck; } -private: - /// Check if a single basic block loop is vectorizable. - /// At this point we know that this is a loop with a constant trip count - /// and we only need to check individual instructions. - bool canVectorizeInstrs(); - - /// When we vectorize loops we may change the order in which - /// we read and write from memory. This method checks if it is - /// legal to vectorize the code, considering only memory constrains. - /// Returns true if the loop is vectorizable - bool canVectorizeMemory(); - - /// Return true if we can vectorize this loop using the IF-conversion - /// transformation. - bool canVectorizeWithIfConvert(); - - /// Collect the variables that need to stay uniform after vectorization. - void collectLoopUniforms(); - - /// Return true if all of the instructions in the block can be speculatively - /// executed. - bool blockCanBePredicated(BasicBlock *BB); - - /// Returns True, if 'Phi' is the kind of reduction variable for type - /// 'Kind'. If this is a reduction variable, it adds it to ReductionList. - bool AddReductionVar(PHINode *Phi, ReductionKind Kind); - /// Returns true if the instruction I can be a reduction variable of type - /// 'Kind'. - bool isReductionInstr(Instruction *I, ReductionKind Kind); - /// Returns the induction kind of Phi. This function may return NoInduction - /// if the PHI is not an induction variable. - InductionKind isInductionVariable(PHINode *Phi); - /// Return true if can compute the address bounds of Ptr within the loop. - bool hasComputableBounds(Value *Ptr); - - /// The loop that we evaluate. - Loop *TheLoop; - /// Scev analysis. - ScalarEvolution *SE; - /// DataLayout analysis. - DataLayout *DL; - // Dominators. - DominatorTree *DT; - - // --- vectorization state --- // - - /// Holds the integer induction variable. This is the counter of the - /// loop. - PHINode *Induction; - /// Holds the reduction variables. - ReductionList Reductions; - /// Holds all of the induction variables that we found in the loop. - /// Notice that inductions don't need to start at zero and that induction - /// variables can be pointers. - InductionList Inductions; - - /// Allowed outside users. This holds the reduction - /// vars which can be accessed from outside the loop. - SmallPtrSet<Value*, 4> AllowedExit; - /// This set holds the variables which are known to be uniform after - /// vectorization. - SmallPtrSet<Instruction*, 4> Uniforms; - /// We need to check that all of the pointers in this list are disjoint - /// at runtime. - RuntimePointerCheck PtrRtCheck; -}; - -/// LoopVectorizationCostModel - estimates the expected speedups due to -/// vectorization. -/// In many cases vectorization is not profitable. This can happen because -/// of a number of reasons. In this class we mainly attempt to predict -/// the expected speedup/slowdowns due to the supported instruction set. -/// We use the VectorTargetTransformInfo to query the different backends -/// for the cost of different operations. -class LoopVectorizationCostModel { -public: - /// C'tor. - LoopVectorizationCostModel(Loop *Lp, ScalarEvolution *Se, - LoopVectorizationLegality *Leg, - const VectorTargetTransformInfo *Vtti): - TheLoop(Lp), SE(Se), Legal(Leg), VTTI(Vtti) { } - - /// Returns the most profitable vectorization factor for the loop that is - /// smaller or equal to the VF argument. This method checks every power - /// of two up to VF. - unsigned findBestVectorizationFactor(unsigned VF = MaxVectorSize); - -private: - /// Returns the expected execution cost. The unit of the cost does - /// not matter because we use the 'cost' units to compare different - /// vector widths. The cost that is returned is *not* normalized by - /// the factor width. - unsigned expectedCost(unsigned VF); - - /// Returns the execution time cost of an instruction for a given vector - /// width. Vector width of one means scalar. - unsigned getInstructionCost(Instruction *I, unsigned VF); - - /// A helper function for converting Scalar types to vector types. - /// If the incoming type is void, we return void. If the VF is 1, we return - /// the scalar type. - static Type* ToVectorTy(Type *Scalar, unsigned VF); - - /// The loop that we evaluate. - Loop *TheLoop; - /// Scev analysis. - ScalarEvolution *SE; - - /// Vectorization legality. - LoopVectorizationLegality *Legal; - /// Vector target information. - const VectorTargetTransformInfo *VTTI; -}; - -}// namespace llvm - -#endif //LLVM_TRANSFORM_VECTORIZE_LOOP_VECTORIZE_H - diff --git a/lib/Transforms/Vectorize/Vectorize.cpp b/lib/Transforms/Vectorize/Vectorize.cpp index 3fb36cadea..19eefd2f87 100644 --- a/lib/Transforms/Vectorize/Vectorize.cpp +++ b/lib/Transforms/Vectorize/Vectorize.cpp @@ -1,4 +1,4 @@ -//===-- Vectorize.cpp -----------------------------------------------------===// + //===-- Vectorize.cpp -----------------------------------------------------===// // // The LLVM Compiler Infrastructure // |