[clang] [PGO] Add ability to mark cold functions as optsize/minsize/optnone (PR #69030)

[David Li via cfe-commits]

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@@ -0,0 +1,65 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Instrumentation/MarkColdFunctions.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
+#include "llvm/IR/PassManager.h"
+
+using namespace llvm;
+
+PreservedAnalyses MarkColdFunctionsPass::run(Module &M,
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david-xl wrote:

why not just mark those function with 'cold' attribute, and have one global option to determine the optimization strategy of cold attributed functions? These functions are not different from functions annotated by a developer.

https://github.com/llvm/llvm-project/pull/69030