[llvm] [MemProf] Support for random hotness when writing profile (PR #113998)

[Snehasish Kumar via llvm-commits]

================
@@ -273,13 +291,37 @@ void InstrProfWriter::addRecord(StringRef Name, uint64_t Hash,
 
 void InstrProfWriter::addMemProfRecord(
     const Function::GUID Id, const memprof::IndexedMemProfRecord &Record) {
-  auto [Iter, Inserted] = MemProfData.Records.insert({Id, Record});
+  auto NewRecord = Record;
+  // Provoke random hotness values if requested. We specify the lifetime access
+  // density and lifetime length that will result in a cold or not cold hotness.
+  // See the logic in getAllocType() in Analysis/MemoryProfileInfo.cpp.
+  if (MemprofGenerateRandomHotness) {
+    for (auto &Alloc : NewRecord.AllocSites) {
+      uint64_t NewTLAD = 0;
----------------
snehasish wrote:

If you initialize NewTLAD to `NewTLAD = std::numeric_limits<uint64_t>::max();` here instead then you can skip the else below. Also hoist the comment out of the else block.

https://github.com/llvm/llvm-project/pull/113998