[Analysis] Refactor MBB hotness/coldness into templated PSI functions.

Currently, to use PSI->isFunctionHotInCallGraph, we first need to
calculate BPI->BFI, which is expensive. Instead, we can implement this
directly with MBFI. Also as @wenlei mentioned in another patch review,
that MachineSizeOpts already has isFunctionColdInCallGraph,
isFunctionHotInCallGraphNthPercentile, etc implemented. These can be
refactored and so they can be reused across MachineFunctionSplitting
and MachineSizeOpts passes.

This CL does this - it refactors out those internal static functions
into PSI as templated functions, so they can be accessed easily.

Differential Revision: https://reviews.llvm.org/D153927

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineFunction.cpp b/llvm/lib/CodeGen/MachineFunction.cpp
index 0f72e4b..a934a5c 100644
--- a/llvm/lib/CodeGen/MachineFunction.cpp
+++ b/llvm/lib/CodeGen/MachineFunction.cpp
@@ -22,6 +22,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
@@ -1496,6 +1497,17 @@ void MachineConstantPool::print(raw_ostream &OS) const {
   }
 }
 
+//===----------------------------------------------------------------------===//
+// Template specialization for MachineFunction implementation of
+// ProfileSummaryInfo::getEntryCount().
+//===----------------------------------------------------------------------===//
+template <>
+std::optional<Function::ProfileCount>
+ProfileSummaryInfo::getEntryCount<llvm::MachineFunction>(
+    const llvm::MachineFunction *F) const {
+  return F->getFunction().getEntryCount();
+}
+
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 LLVM_DUMP_METHOD void MachineConstantPool::dump() const { print(dbgs()); }
 #endif