Index: include/llvm/IR/Module.h
===================================================================
--- include/llvm/IR/Module.h
+++ include/llvm/IR/Module.h
@@ -639,7 +639,7 @@
   void setPICLevel(PICLevel::Level PL);
 /// @}
 
-  /// @name Utility functions for querying and setting PGO counts
+  /// @name Utility functions for querying and setting PGO summary
   /// @{
 
   /// \brief Set maximum function count in PGO mode
@@ -647,6 +647,12 @@
 
   /// \brief Returns maximum function count in PGO mode
   Optional<uint64_t> getMaximumFunctionCount();
+
+  /// \brief Attach profile summary metadata to this module.
+  void setProfileSummary(Metadata *M);
+
+  /// \brief Returns profile summary metadata
+  Metadata *getProfileSummary();
   /// @}
 };
 
Index: lib/IR/Module.cpp
===================================================================
--- lib/IR/Module.cpp
+++ lib/IR/Module.cpp
@@ -485,3 +485,11 @@
     return None;
   return cast<ConstantInt>(Val->getValue())->getZExtValue();
 }
+
+void Module::setProfileSummary(Metadata *M) {
+  addModuleFlag(ModFlagBehavior::Error, "ProfileSummary", M);
+}
+
+Metadata *Module::getProfileSummary() {
+  return getModuleFlag("ProfileSummary");
+}