1 files changed, 15 insertions, 5 deletions
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index e043d07..08be5df 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -1534,8 +1534,8 @@ bool MemCpyOptPass::performStackMoveOptzn(Instruction *Load, Instruction *Store,
   bool SrcNotDom = false;
 
   auto CaptureTrackingWithModRef =
-      [&](Instruction *AI,
-          function_ref<bool(Instruction *)> ModRefCallback) -> bool {
+      [&](Instruction *AI, function_ref<bool(Instruction *)> ModRefCallback,
+          bool &AddressCaptured) -> bool {
     SmallVector<Instruction *, 8> Worklist;
     Worklist.push_back(AI);
     unsigned MaxUsesToExplore = getDefaultMaxUsesToExploreForCaptureTracking();
@@ -1559,8 +1559,9 @@ bool MemCpyOptPass::performStackMoveOptzn(Instruction *Load, Instruction *Store,
         if (!Visited.insert(&U).second)
           continue;
         UseCaptureInfo CI = DetermineUseCaptureKind(U, AI);
-        if (capturesAnything(CI.UseCC))
+        if (capturesAnyProvenance(CI.UseCC))
           return false;
+        AddressCaptured |= capturesAddress(CI.UseCC);
 
         if (UI->mayReadOrWriteMemory()) {
           if (UI->isLifetimeStartOrEnd()) {
@@ -1627,7 +1628,9 @@ bool MemCpyOptPass::performStackMoveOptzn(Instruction *Load, Instruction *Store,
     return true;
   };
 
-  if (!CaptureTrackingWithModRef(DestAlloca, DestModRefCallback))
+  bool DestAddressCaptured = false;
+  if (!CaptureTrackingWithModRef(DestAlloca, DestModRefCallback,
+                                 DestAddressCaptured))
     return false;
   // Bailout if Dest may have any ModRef before Store.
   if (!ReachabilityWorklist.empty() &&
@@ -1653,7 +1656,14 @@ bool MemCpyOptPass::performStackMoveOptzn(Instruction *Load, Instruction *Store,
     return true;
   };
 
-  if (!CaptureTrackingWithModRef(SrcAlloca, SrcModRefCallback))
+  bool SrcAddressCaptured = false;
+  if (!CaptureTrackingWithModRef(SrcAlloca, SrcModRefCallback,
+                                 SrcAddressCaptured))
+    return false;
+
+  // If both the source and destination address are captured, the fact that they
+  // are no longer two separate allocations may be observed.
+  if (DestAddressCaptured && SrcAddressCaptured)
     return false;
 
   // We can do the transformation. First, move the SrcAlloca to the start of the