[llvm] Adding Matching and Inference Functionality to Propeller-Patch 1 (PR #140886)

[via llvm-commits]

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@@ -0,0 +1,108 @@
+#ifndef LLVM_CODEGEN_MACHINEBLOCKHASHINFO_H
+#define LLVM_CODEGEN_MACHINEBLOCKHASHINFO_H
+
+#include "llvm/CodeGen/MachineFunctionPass.h"
+
+namespace llvm {
+
+/// An object wrapping several components of a basic block hash. The combined
+/// (blended) hash is represented and stored as one uint64_t, while individual
+/// components are of smaller size (e.g., uint16_t or uint8_t).
+struct BlendedBlockHash {
+private:
+  static uint64_t combineHashes(uint16_t Hash1, uint16_t Hash2, uint16_t Hash3,
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spupyrev wrote:

A lot of the code in this file repeats the implementation in BOLT (which has actually been improved since the original commits), e.g., https://github.com/llvm/llvm-project/blob/main/bolt/lib/Profile/StaleProfileMatching.cpp

Do you think there is a way to unify the implementations? (totally understand if not, since there might be some specifics)

https://github.com/llvm/llvm-project/pull/140886