Index: lib/CodeGen/BackendUtil.cpp
===================================================================
--- lib/CodeGen/BackendUtil.cpp
+++ lib/CodeGen/BackendUtil.cpp
@@ -150,6 +150,12 @@
   PM.add(createAddDiscriminatorsPass());
 }
 
+static void addPGOOnlyOptimizations(
+    const PassManagerBuilder &Builder, legacy::PassManagerBase &PM) {
+  PM.add(createLoopSinkPass());
+  PM.add(createInstructionSimplifierPass());
+}
+
 static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
                                   legacy::PassManagerBase &PM) {
   PM.add(createBoundsCheckingPass());
@@ -459,6 +465,10 @@
     MPM.add(createSampleProfileLoaderPass(CodeGenOpts.SampleProfileFile));
   }
 
+  if (!CodeGenOpts.SampleProfileFile.empty() || CodeGenOpts.hasProfileIRUse())
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addPGOOnlyOptimizations);
+
   PMBuilder.populateFunctionPassManager(FPM);
   PMBuilder.populateModulePassManager(MPM);
 }