diff --git a/llvm/include/llvm/Analysis/LoopDependenceAnalysis.h b/llvm/include/llvm/Analysis/LoopDependenceAnalysis.h index 236f79ae9706..272e0bd4d362 100644 --- a/llvm/include/llvm/Analysis/LoopDependenceAnalysis.h +++ b/llvm/include/llvm/Analysis/LoopDependenceAnalysis.h @@ -20,6 +20,7 @@ #ifndef LLVM_ANALYSIS_LOOP_DEPENDENCE_ANALYSIS_H #define LLVM_ANALYSIS_LOOP_DEPENDENCE_ANALYSIS_H +#include "llvm/ADT/DenseSet.h" #include "llvm/ADT/FoldingSet.h" #include "llvm/ADT/SmallVector.h" #include "llvm/Analysis/LoopPass.h" @@ -67,6 +68,10 @@ class LoopDependenceAnalysis : public LoopPass { /// created. The third argument is set to the pair found or created. bool findOrInsertDependencePair(Value*, Value*, DependencePair*&); + /// getLoops - Collect all loops of the loop-nest L a given SCEV is variant + /// in. + void getLoops(const SCEV*, DenseSet*) const; + /// isLoopInvariant - True if a given SCEV is invariant in all loops of the /// loop-nest starting at the innermost loop L. bool isLoopInvariant(const SCEV*) const; @@ -78,7 +83,10 @@ class LoopDependenceAnalysis : public LoopPass { /// TODO: doc bool isZIVPair(const SCEV*, const SCEV*) const; + bool isSIVPair(const SCEV*, const SCEV*) const; DependenceResult analyseZIV(const SCEV*, const SCEV*, Subscript*) const; + DependenceResult analyseSIV(const SCEV*, const SCEV*, Subscript*) const; + DependenceResult analyseMIV(const SCEV*, const SCEV*, Subscript*) const; DependenceResult analyseSubscript(const SCEV*, const SCEV*, Subscript*) const; DependenceResult analysePair(DependencePair*) const; diff --git a/llvm/lib/Analysis/LoopDependenceAnalysis.cpp b/llvm/lib/Analysis/LoopDependenceAnalysis.cpp index eb8ea0ebdb0b..d37273c37282 100644 --- a/llvm/lib/Analysis/LoopDependenceAnalysis.cpp +++ b/llvm/lib/Analysis/LoopDependenceAnalysis.cpp @@ -20,6 +20,7 @@ //===----------------------------------------------------------------------===// #define DEBUG_TYPE "lda" +#include "llvm/ADT/DenseSet.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/LoopDependenceAnalysis.h" @@ -124,11 +125,18 @@ bool LoopDependenceAnalysis::findOrInsertDependencePair(Value *A, 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; + 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 +148,13 @@ 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, @@ -148,6 +163,20 @@ 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, @@ -167,10 +196,10 @@ LoopDependenceAnalysis::analyseSubscript(const SCEV *A, 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