add a validity check that was missed, fixing a crash on the

new testcase.

llvm-svn: 122662

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index 9878a2e4e83..8c788039d6b 100644
--- a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -234,6 +234,11 @@ bool LoopIdiomRecognize::
 processLoopStoreOfSplatValue(StoreInst *SI, unsigned StoreSize,
                              Value *SplatValue,
                              const SCEVAddRecExpr *Ev, const SCEV *BECount) {
+  // Verify that the stored value is loop invariant.  If not, we can't promote
+  // the memset.
+  if (!CurLoop->isLoopInvariant(SplatValue))
+    return false;
+  
   // Temporarily remove the store from the loop, to avoid the mod/ref query from
   // seeing it.
   Instruction *InstAfterStore = ++BasicBlock::iterator(SI);