Index: include/llvm/IR/Module.h
===================================================================
--- include/llvm/IR/Module.h
+++ include/llvm/IR/Module.h
@@ -15,6 +15,8 @@
 #ifndef LLVM_IR_MODULE_H
 #define LLVM_IR_MODULE_H
 
+#include <system_error>
+#include "llvm/ADT/Optional.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/IR/Comdat.h"
 #include "llvm/IR/DataLayout.h"
@@ -25,7 +27,6 @@
 #include "llvm/Support/CBindingWrapping.h"
 #include "llvm/Support/CodeGen.h"
 #include "llvm/Support/DataTypes.h"
-#include <system_error>
 
 namespace llvm {
 class FunctionType;
@@ -639,6 +640,16 @@
   /// \brief Set the PIC level (small or large model)
   void setPICLevel(PICLevel::Level PL);
 /// @}
+
+  /// @name Utility functions for querying and setting PGO counts
+  /// @{
+
+  /// \brief Set maximum function count in PGO mode
+  void setMaximumFunctionCount(uint64_t);
+
+  /// \brief Returns maximum function count in PGO mode
+  Optional<uint64_t> getMaximumFunctionCount();
+  /// @}
 };
 
 /// An raw_ostream inserter for modules.
Index: lib/IR/Module.cpp
===================================================================
--- lib/IR/Module.cpp
+++ lib/IR/Module.cpp
@@ -491,3 +491,14 @@
 void Module::setPICLevel(PICLevel::Level PL) {
   addModuleFlag(ModFlagBehavior::Error, "PIC Level", PL);
 }
+
+void Module::setMaximumFunctionCount(uint64_t Count) {
+  addModuleFlag(ModFlagBehavior::Error, "MaxFunctionCount", Count);
+}
+
+Optional<uint64_t> Module::getMaximumFunctionCount() {
+  auto *Val =
+      cast_or_null<ConstantAsMetadata>(getModuleFlag("MaxFunctionCount"));
+  if (!Val) return None;
+  return cast<ConstantInt>(Val->getValue())->getZExtValue();
+}