X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FLoopDependenceAnalysis.cpp;h=c1afe8fbd61834da3573c1a07a2eea09a46a791a;hb=92e946630d5f9bb092853b93501387dd216899b9;hp=eb8ea0ebdb0b1cdc8bafd2fdad00d6e858a7efb8;hpb=6151f672854f59743aeb34019a6926259dec9933;p=oota-llvm.git diff --git a/lib/Analysis/LoopDependenceAnalysis.cpp b/lib/Analysis/LoopDependenceAnalysis.cpp index eb8ea0ebdb0..c1afe8fbd61 100644 --- a/lib/Analysis/LoopDependenceAnalysis.cpp +++ b/lib/Analysis/LoopDependenceAnalysis.cpp @@ -20,12 +20,15 @@ //===----------------------------------------------------------------------===// #define DEBUG_TYPE "lda" +#include "llvm/ADT/DenseSet.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/LoopDependenceAnalysis.h" #include "llvm/Analysis/LoopPass.h" #include "llvm/Analysis/ScalarEvolution.h" #include "llvm/Analysis/ScalarEvolutionExpressions.h" +#include "llvm/Analysis/ValueTracking.h" +#include "llvm/Assembly/Writer.h" #include "llvm/Instructions.h" #include "llvm/Operator.h" #include "llvm/Support/Allocator.h" @@ -45,8 +48,12 @@ LoopPass *llvm::createLoopDependenceAnalysisPass() { return new LoopDependenceAnalysis(); } -static RegisterPass -R("lda", "Loop Dependence Analysis", false, true); +INITIALIZE_PASS_BEGIN(LoopDependenceAnalysis, "lda", + "Loop Dependence Analysis", false, true) +INITIALIZE_PASS_DEPENDENCY(ScalarEvolution) +INITIALIZE_AG_DEPENDENCY(AliasAnalysis) +INITIALIZE_PASS_END(LoopDependenceAnalysis, "lda", + "Loop Dependence Analysis", false, true) char LoopDependenceAnalysis::ID = 0; //===----------------------------------------------------------------------===// @@ -85,14 +92,14 @@ static Value *GetPointerOperand(Value *I) { static AliasAnalysis::AliasResult UnderlyingObjectsAlias(AliasAnalysis *AA, const Value *A, const Value *B) { - const Value *aObj = A->getUnderlyingObject(); - const Value *bObj = B->getUnderlyingObject(); + const Value *aObj = GetUnderlyingObject(A); + const Value *bObj = GetUnderlyingObject(B); return AA->alias(aObj, AA->getTypeStoreSize(aObj->getType()), bObj, AA->getTypeStoreSize(bObj->getType())); } static inline const SCEV *GetZeroSCEV(ScalarEvolution *SE) { - return SE->getConstant(Type::Int32Ty, 0L); + return SE->getConstant(Type::getInt32Ty(SE->getContext()), 0L); } //===----------------------------------------------------------------------===// @@ -118,17 +125,23 @@ bool LoopDependenceAnalysis::findOrInsertDependencePair(Value *A, P = Pairs.FindNodeOrInsertPos(id, insertPos); if (P) return true; - P = PairAllocator.Allocate(); - new (P) DependencePair(id, A, B); + P = new (PairAllocator) DependencePair(id, A, B); Pairs.InsertNode(P, insertPos); return false; } -bool LoopDependenceAnalysis::isLoopInvariant(const SCEV *S) const { +void LoopDependenceAnalysis::getLoops(const SCEV *S, + DenseSet* Loops) const { + // Refactor this into an SCEVVisitor, if efficiency becomes a concern. for (const Loop *L = this->L; L != 0; L = L->getParentLoop()) - if (!S->isLoopInvariant(L)) - return false; - return true; + if (!SE->isLoopInvariant(S, L)) + Loops->insert(L); +} + +bool LoopDependenceAnalysis::isLoopInvariant(const SCEV *S) const { + DenseSet loops; + getLoops(S, &loops); + return loops.empty(); } bool LoopDependenceAnalysis::isAffine(const SCEV *S) const { @@ -140,6 +153,13 @@ bool LoopDependenceAnalysis::isZIVPair(const SCEV *A, const SCEV *B) const { return isLoopInvariant(A) && isLoopInvariant(B); } +bool LoopDependenceAnalysis::isSIVPair(const SCEV *A, const SCEV *B) const { + DenseSet loops; + getLoops(A, &loops); + getLoops(B, &loops); + return loops.size() == 1; +} + LoopDependenceAnalysis::DependenceResult LoopDependenceAnalysis::analyseZIV(const SCEV *A, const SCEV *B, @@ -148,39 +168,53 @@ LoopDependenceAnalysis::analyseZIV(const SCEV *A, return A == B ? Dependent : Independent; } +LoopDependenceAnalysis::DependenceResult +LoopDependenceAnalysis::analyseSIV(const SCEV *A, + const SCEV *B, + Subscript *S) const { + return Unknown; // TODO: Implement. +} + +LoopDependenceAnalysis::DependenceResult +LoopDependenceAnalysis::analyseMIV(const SCEV *A, + const SCEV *B, + Subscript *S) const { + return Unknown; // TODO: Implement. +} + LoopDependenceAnalysis::DependenceResult LoopDependenceAnalysis::analyseSubscript(const SCEV *A, const SCEV *B, Subscript *S) const { - DEBUG(errs() << " Testing subscript: " << *A << ", " << *B << "\n"); + DEBUG(dbgs() << " Testing subscript: " << *A << ", " << *B << "\n"); if (A == B) { - DEBUG(errs() << " -> [D] same SCEV\n"); + DEBUG(dbgs() << " -> [D] same SCEV\n"); return Dependent; } if (!isAffine(A) || !isAffine(B)) { - DEBUG(errs() << " -> [?] not affine\n"); + DEBUG(dbgs() << " -> [?] not affine\n"); return Unknown; } if (isZIVPair(A, B)) return analyseZIV(A, B, S); - // TODO: Implement SIV/MIV testers. + if (isSIVPair(A, B)) + return analyseSIV(A, B, S); - DEBUG(errs() << " -> [?] cannot analyse subscript\n"); - return Unknown; + return analyseMIV(A, B, S); } LoopDependenceAnalysis::DependenceResult LoopDependenceAnalysis::analysePair(DependencePair *P) const { - DEBUG(errs() << "Analysing:\n" << *P->A << "\n" << *P->B << "\n"); + DEBUG(dbgs() << "Analysing:\n" << *P->A << "\n" << *P->B << "\n"); // We only analyse loads and stores but no possible memory accesses by e.g. // free, call, or invoke instructions. if (!IsLoadOrStoreInst(P->A) || !IsLoadOrStoreInst(P->B)) { - DEBUG(errs() << "--> [?] no load/store\n"); + DEBUG(dbgs() << "--> [?] no load/store\n"); return Unknown; } @@ -189,13 +223,14 @@ LoopDependenceAnalysis::analysePair(DependencePair *P) const { switch (UnderlyingObjectsAlias(AA, aPtr, bPtr)) { case AliasAnalysis::MayAlias: + case AliasAnalysis::PartialAlias: // We can not analyse objects if we do not know about their aliasing. - DEBUG(errs() << "---> [?] may alias\n"); + DEBUG(dbgs() << "---> [?] may alias\n"); return Unknown; case AliasAnalysis::NoAlias: // If the objects noalias, they are distinct, accesses are independent. - DEBUG(errs() << "---> [I] no alias\n"); + DEBUG(dbgs() << "---> [I] no alias\n"); return Independent; case AliasAnalysis::MustAlias: @@ -321,8 +356,3 @@ void LoopDependenceAnalysis::print(raw_ostream &OS, const Module*) const { // TODO: doc why const_cast is safe PrintLoopInfo(OS, const_cast(this), this->L); } - -void LoopDependenceAnalysis::print(std::ostream &OS, const Module *M) const { - raw_os_ostream os(OS); - print(os, M); -}