diff --git a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
@@ -985,6 +985,7 @@
     return false; // FIXME
 
   IRBuilder<> IRB(O.getInsn());
+  IRB.CreateFence(AtomicOrdering::Acquire, SyncScope::SingleThread);
   if (isPowerOf2_64(O.TypeSize) &&
       (O.TypeSize / 8 <= (1ULL << (kNumberOfAccessSizes - 1))) &&
       (!O.Alignment || *O.Alignment >= (1ULL << Mapping.Scale) ||
@@ -1048,6 +1049,7 @@
                                    Int8Ty, IRB.CreateBitCast(AI, Int8PtrTy),
                                    AlignedSize - 1));
     }
+    IRB.CreateFence(AtomicOrdering::Release, SyncScope::SingleThread);
   }
 }