Interface to attach maximum function count from PGO to module as module flags.

This provides interface to get and set maximum function counts to Module. This
would allow things like determination of function hotness. The actual setting
of this max function count will have to be done in the frontend.

Differential Revision: http://reviews.llvm.org/D15003

llvm-svn: 254647

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index 2b9adad44ba..2acd9db210d 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -491,3 +491,15 @@ PICLevel::Level Module::getPICLevel() const {
 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();
+}