[llvm-branch-commits] [llvm] [BOLT] Hash-based function matching (PR #95821)

[Alexander Yermolovich via llvm-branch-commits]

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@@ -374,15 +377,33 @@ Error YAMLProfileReader::readProfile(BinaryContext &BC) {
     // the profile.
     Function.setExecutionCount(BinaryFunction::COUNT_NO_PROFILE);
 
-    // Recompute hash once per function.
-    if (!opts::IgnoreHash)
-      Function.computeHash(YamlBP.Header.IsDFSOrder,
-                           YamlBP.Header.HashFunction);
-
     if (profileMatches(YamlBF, Function))
       matchProfileToFunction(YamlBF, Function);
   }
 
+  // Uses the strict hash of profiled and binary functions to match functions
+  // that are not matched by name or common name.
+  if (!opts::IgnoreHash) {
+    std::unordered_map<size_t, BinaryFunction *> StrictHashToBF;
+    StrictHashToBF.reserve(BC.getBinaryFunctions().size());
+
+    for (auto &[_, BF] : BC.getBinaryFunctions()) {
+      StrictHashToBF[BF.getHash()] = &BF;
+    }
+
+    for (auto YamlBF : YamlBP.Functions) {
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ayermolo wrote:

Specify actual type.
This can also hide copy since & is not used.

https://github.com/llvm/llvm-project/pull/95821