ZIV tester for LDA.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78157 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/LoopDependenceAnalysis.cpp b/lib/Analysis/LoopDependenceAnalysis.cpp
index 5d593a9..10a6a8e 100644
--- a/lib/Analysis/LoopDependenceAnalysis.cpp
+++ b/lib/Analysis/LoopDependenceAnalysis.cpp
@@ -136,6 +136,19 @@
return isLoopInvariant(S) || (rec && rec->isAffine());
}
+bool LoopDependenceAnalysis::isZIVPair(const SCEV *A, const SCEV *B) const {
+ return isLoopInvariant(A) && isLoopInvariant(B);
+}
+
+LoopDependenceAnalysis::DependenceResult
+LoopDependenceAnalysis::analyseZIV(const SCEV *A,
+ const SCEV *B,
+ Subscript *S) const {
+ assert(isZIVPair(A, B));
+ const SCEV *diff = SE->getMinusSCEV(A, B);
+ return diff->isZero() ? Dependent : Independent;
+}
+
LoopDependenceAnalysis::DependenceResult
LoopDependenceAnalysis::analyseSubscript(const SCEV *A,
const SCEV *B,
@@ -152,7 +165,10 @@
return Unknown;
}
- // TODO: Implement ZIV/SIV/MIV testers.
+ if (isZIVPair(A, B))
+ return analyseZIV(A, B, S);
+
+ // TODO: Implement SIV/MIV testers.
DEBUG(errs() << " -> [?] cannot analyse subscript\n");
return Unknown;