[llvm] [SampleFDO] Stale profile call-graph matching (PR #95135)

[David Li via llvm-commits]

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@@ -127,8 +147,37 @@ void SampleProfileMatcher::findProfileAnchors(const FunctionSamples &FS,
   }
 }
 
-LocToLocMap SampleProfileMatcher::longestCommonSequence(
-    const AnchorList &AnchorList1, const AnchorList &AnchorList2) const {
+bool SampleProfileMatcher::isFunctionEqual(const FunctionId &IRFuncName,
+                                           const FunctionId &ProfileFuncName,
+                                           bool FindMatchedProfileOnly) {
+  if (IRFuncName == ProfileFuncName)
+    return true;
+  if (!SalvageUnusedProfile)
+    return false;
+  // If both IR function and profile function are new, try to match the profile
+  // function.
+
+  // Check whether IR function is new.
+  auto R = NewIRFunctions.find(IRFuncName);
+  if (R == NewIRFunctions.end() || !R->second)
+    return false;
+  Function &IRFunc = *R->second;
+  assert(FunctionId(IRFunc.getName()) != ProfileFuncName &&
+         "IR function should be different from profile function to match");
+
+  // Check whether profile function is new.
----------------
david-xl wrote:

How can a profile function be new?

https://github.com/llvm/llvm-project/pull/95135