[llvm] [MemProf] Handle missing tail call frames (PR #75823)

[Teresa Johnson via llvm-commits]

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@@ -1642,8 +1718,160 @@ uint64_t IndexCallsiteContextGraph::getStackId(uint64_t IdOrIndex) const {
   return Index.getStackIdAtIndex(IdOrIndex);
 }
 
-bool ModuleCallsiteContextGraph::calleeMatchesFunc(Instruction *Call,
-                                                   const Function *Func) {
+template <typename DerivedCCG, typename FuncTy, typename CallTy>
+bool CallsiteContextGraph<DerivedCCG, FuncTy, CallTy>::calleesMatch(
+    CallTy Call, EdgeIter &EI,
+    MapVector<CallInfo, ContextNode *> &TailCallToContextNodeMap) {
+  auto Edge = *EI;
+  const FuncTy *ProfiledCalleeFunc = NodeToCallingFunc[Edge->Callee];
+  const FuncTy *CallerFunc = NodeToCallingFunc[Edge->Caller];
+  // Will be populated in order of callee to caller if we find a chain of tail
+  // calls between the profiled caller and callee.
+  std::vector<std::pair<CallTy, FuncTy *>> FoundCalleeChain;
+  if (!calleeMatchesFunc(Call, ProfiledCalleeFunc, CallerFunc,
+                         FoundCalleeChain)) {
+    ++EI;
+    return false;
+  }
+
+  // The usual case where the profiled callee matches that of the IR/summary.
+  if (FoundCalleeChain.empty()) {
+    ++EI;
+    return true;
+  }
+
+  auto AddEdge = [Edge, &EI](ContextNode *Caller, ContextNode *Callee) {
+    auto *CurEdge = Callee->findEdgeFromCaller(Caller);
+    // If there is already an edge between these nodes, simply update it and
+    // return.
+    if (CurEdge) {
+      CurEdge->ContextIds.insert(Edge->ContextIds.begin(),
+                                 Edge->ContextIds.end());
+      CurEdge->AllocTypes |= Edge->AllocTypes;
+      return;
+    }
+    // Otherwise, create a new edge and insert it into the caller and callee
+    // lists.
+    auto NewEdge = std::make_shared<ContextEdge>(
+        Callee, Caller, Edge->AllocTypes, Edge->ContextIds);
+    Callee->CallerEdges.push_back(NewEdge);
+    if (Caller == Edge->Caller) {
+      // If we are inserting the new edge into the current edge's caller, insert
+      // the new edge before the current iterator position, and then increment
+      // back to the current edge.
+      EI = Caller->CalleeEdges.insert(EI, NewEdge);
+      ++EI;
+      assert(*EI == Edge);
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teresajohnson wrote:

done

https://github.com/llvm/llvm-project/pull/75823