[llvm-branch-commits] [llvm] [BOLT] Match blocks with calls as anchors (PR #96596)

[Amir Ayupov via llvm-branch-commits]

================
@@ -193,18 +193,43 @@ class StaleMatcher {
 public:
   /// Initialize stale matcher.
   void init(const std::vector<FlowBlock *> &Blocks,
-            const std::vector<BlendedBlockHash> &Hashes) {
+            const std::vector<BlendedBlockHash> &Hashes,
+            const std::vector<uint64_t> &CallHashes) {
     assert(Blocks.size() == Hashes.size() &&
+           Hashes.size() == CallHashes.size() &&
            "incorrect matcher initialization");
     for (size_t I = 0; I < Blocks.size(); I++) {
       FlowBlock *Block = Blocks[I];
       uint16_t OpHash = Hashes[I].OpcodeHash;
       OpHashToBlocks[OpHash].push_back(std::make_pair(Hashes[I], Block));
+      if (CallHashes[I])
+        CallHashToBlocks[CallHashes[I]].push_back(
+            std::make_pair(Hashes[I], Block));
     }
   }
 
   /// Find the most similar block for a given hash.
-  const FlowBlock *matchBlock(BlendedBlockHash BlendedHash) const {
+  const FlowBlock *matchBlock(BlendedBlockHash &BlendedHash,
+                              uint64_t &CallHash) const {
----------------
aaupov wrote:

```suggestion
  const FlowBlock *matchBlock(BlendedBlockHash BlendedHash,
                              uint64_t CallHash) const {
```
BlendedBlockHash is aliased to uint64_t, and integral types should be passed by value.

https://github.com/llvm/llvm-project/pull/96596