Index: lib/Transforms/IPO/PassManagerBuilder.cpp
===================================================================
--- lib/Transforms/IPO/PassManagerBuilder.cpp
+++ lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -70,6 +70,10 @@
   cl::init(false), cl::Hidden,
   cl::desc("Enable the new, experimental CFL alias analysis"));
 
+static cl::opt<bool>
+EnableMLSM("mlsm", cl::desc("Enable motion of merged load and store"),
+           cl::init(true));
+
 PassManagerBuilder::PassManagerBuilder() {
     OptLevel = 2;
     SizeLevel = 0;
@@ -228,7 +232,9 @@
   addExtensionsToPM(EP_LoopOptimizerEnd, MPM);
 
   if (OptLevel > 1) {
-    MPM.add(createMergedLoadStoreMotionPass()); // Merge load/stores in diamond
+    if (EnableMLSM)
+      MPM.add(
+          createMergedLoadStoreMotionPass());   // Merge load/stores in diamond
     MPM.add(createGVNPass(DisableGVNLoadPRE));  // Remove redundancies
   }
   MPM.add(createMemCpyOptPass());             // Remove memcpy / form memset
@@ -388,7 +394,8 @@
   PM.add(createGlobalsModRefPass()); // IP alias analysis.
 
   PM.add(createLICMPass());                 // Hoist loop invariants.
-  PM.add(createMergedLoadStoreMotionPass()); // Merge load/stores in diamonds
+  if (EnableMLSM)
+    PM.add(createMergedLoadStoreMotionPass()); // Merge load/stores in diamonds
   PM.add(createGVNPass(DisableGVNLoadPRE)); // Remove redundancies.
   PM.add(createMemCpyOptPass());            // Remove dead memcpys.
 
Index: lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
===================================================================
--- lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
+++ lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
@@ -97,9 +97,6 @@
 //===----------------------------------------------------------------------===//
 //                         MergedLoadStoreMotion Pass
 //===----------------------------------------------------------------------===//
-static cl::opt<bool>
-EnableMLSM("mlsm", cl::desc("Enable motion of merged load and store"),
-           cl::init(true));
 
 namespace {
 class MergedLoadStoreMotion : public FunctionPass {
@@ -611,8 +608,6 @@
   AA = &getAnalysis<AliasAnalysis>();
 
   bool Changed = false;
-  if (!EnableMLSM)
-    return false;
   DEBUG(dbgs() << "Instruction Merger\n");
 
   // Merge unconditional branches, allowing PRE to catch more