[LoopUnrollAnalyzer] Check that we're using SCEV for the same loop we're simulating.

Summary: Check that we're using SCEV for the same loop we're simulating. Otherwise, we might try to use the iteration number of the current loop in SCEV expressions for inner/outer loops IVs, which is clearly incorrect.

Reviewers: chandlerc, hfinkel

Subscribers: sanjoy, llvm-commits, mzolotukhin

Differential Revision: http://reviews.llvm.org/D17632

llvm-svn: 261958

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/include/llvm/Analysis/LoopUnrollAnalyzer.h b/llvm/include/llvm/Analysis/LoopUnrollAnalyzer.h
index cfcc8ffbe5a..7e827e8737b 100644
--- a/llvm/include/llvm/Analysis/LoopUnrollAnalyzer.h
+++ b/llvm/include/llvm/Analysis/LoopUnrollAnalyzer.h
@@ -48,8 +48,8 @@ class UnrolledInstAnalyzer : private InstVisitor<UnrolledInstAnalyzer, bool> {
 public:
   UnrolledInstAnalyzer(unsigned Iteration,
                        DenseMap<Value *, Constant *> &SimplifiedValues,
-                       ScalarEvolution &SE)
-      : SimplifiedValues(SimplifiedValues), SE(SE) {
+                       ScalarEvolution &SE, const Loop *L)
+      : SimplifiedValues(SimplifiedValues), SE(SE), L(L) {
       IterationNumber = SE.getConstant(APInt(64, Iteration));
   }
 
@@ -80,6 +80,7 @@ private:
   DenseMap<Value *, Constant *> &SimplifiedValues;
 
   ScalarEvolution &SE;
+  const Loop *L;
 
   bool simplifyInstWithSCEV(Instruction *I);