1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index 3d60e205b002..a153f393448c 100644
--- a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -1247,6 +1247,11 @@ bool LoopIdiomRecognize::processLoopStoreOfLoopLoad(
       mayLoopAccessLocation(StoreBasePtr, ModRefInfo::ModRef, CurLoop, BECount,
                             StoreSize, *AA, Stores);
   if (UseMemMove) {
+    // For memmove case it's not enough to guarantee that loop doesn't access
+    // TheStore and TheLoad. Additionally we need to make sure that TheStore is
+    // the only user of TheLoad.
+    if (!TheLoad->hasOneUse())
+      return Changed;
     Stores.insert(TheLoad);
     if (mayLoopAccessLocation(StoreBasePtr, ModRefInfo::ModRef, CurLoop,
                               BECount, StoreSize, *AA, Stores)) {