Index: include/llvm/CodeGen/MachineInstr.h
===================================================================
--- include/llvm/CodeGen/MachineInstr.h
+++ include/llvm/CodeGen/MachineInstr.h
@@ -1170,6 +1170,12 @@
     assert(NumMemRefs == NewMemRefsEnd - NewMemRefs && "Too many memrefs");
   }
 
+  /// clearMemRefs - Clear this MachineInstr's memory reference descriptor list.
+  void clearMemRefs() {
+    MemRefs = nullptr;
+    NumMemRefs = 0;
+  }
+
 private:
   /// getRegInfo - If this instruction is embedded into a MachineFunction,
   /// return the MachineRegisterInfo object for the current function, otherwise
Index: lib/CodeGen/BranchFolding.cpp
===================================================================
--- lib/CodeGen/BranchFolding.cpp
+++ lib/CodeGen/BranchFolding.cpp
@@ -727,6 +727,14 @@
   return true;
 }
 
+static void removeMMOsFromMemoryOperations(MachineBasicBlock &MBB) {
+  // Remove all MMOs from memory operations.  This ensures later passes
+  // conservatively compute dependencies.
+  for (auto &MII : MBB)
+    if (MII.mayLoad() || MII.mayStore())
+      MII.clearMemRefs();
+}
+
 // See if any of the blocks in MergePotentials (which all have a common single
 // successor, or all have no successor) can be tail-merged.  If there is a
 // successor, any blocks in MergePotentials that are not tail-merged and
@@ -828,6 +836,9 @@
 
     MachineBasicBlock *MBB = SameTails[commonTailIndex].getBlock();
 
+    // Remove all MMOs from memory operations.
+    removeMMOsFromMemoryOperations(*MBB);
+
     // Recompute commont tail MBB's edge weights and block frequency.
     setCommonTailEdgeWeights(*MBB);