+bool LoopDependenceAnalysis::isLoopInvariant(const SCEV *S) const {
+ DenseSet<const Loop*> loops;
+ getLoops(S, &loops);
+ return loops.empty();
+}
+
+bool LoopDependenceAnalysis::isAffine(const SCEV *S) const {
+ const SCEVAddRecExpr *rec = dyn_cast<SCEVAddRecExpr>(S);
+ return isLoopInvariant(S) || (rec && rec->isAffine());
+}
+
+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<const Loop*> loops;
+ getLoops(A, &loops);
+ getLoops(B, &loops);
+ return loops.size() == 1;
+}
+
+LoopDependenceAnalysis::DependenceResult
+LoopDependenceAnalysis::analyseZIV(const SCEV *A,
+ const SCEV *B,
+ Subscript *S) const {
+ assert(isZIVPair(A, B) && "Attempted to ZIV-test non-ZIV SCEVs!");
+ 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(dbgs() << " Testing subscript: " << *A << ", " << *B << "\n");
+
+ if (A == B) {
+ DEBUG(dbgs() << " -> [D] same SCEV\n");
+ return Dependent;
+ }
+
+ if (!isAffine(A) || !isAffine(B)) {
+ DEBUG(dbgs() << " -> [?] not affine\n");
+ return Unknown;
+ }
+
+ if (isZIVPair(A, B))
+ return analyseZIV(A, B, S);
+
+ if (isSIVPair(A, B))
+ return analyseSIV(A, B, S);
+
+ return analyseMIV(A, B, S);
+}
+
+LoopDependenceAnalysis::DependenceResult
+LoopDependenceAnalysis::analysePair(DependencePair *P) const {
+ DEBUG(dbgs() << "Analysing:\n" << *P->A << "\n" << *P->B << "\n");