[llvm] [MemProf] Make sure call clones without callsite node clones get updated (PR #159861)

[Snehasish Kumar via llvm-commits]

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@@ -4986,6 +5014,63 @@ bool CallsiteContextGraph<DerivedCCG, FuncTy, CallTy>::assignFunctions() {
         }
       }
     }
+
+    if (FuncCloneInfos.size() < 2)
+      continue;
+
+    // In this case there is more than just the original function copy.
+    // Record call clones of any callsite nodes in the function that did not
+    // themselves get cloned for all of the function clones.
+    for (auto &Call : CallsWithMetadata) {
+      ContextNode *Node = getNodeForInst(Call);
+      if (!Node || !Node->hasCall() || Node->emptyContextIds())
+        continue;
+      // If Node has enough clones already to cover all function clones, we can
+      // skip it. Need to add one for the original copy.
+      // Use >= in case there were clones that were skipped due to having empty
+      // context ids
+      if (Node->Clones.size() + 1 >= FuncCloneInfos.size())
+        continue;
+      // First collect all function clones we cloned this callsite node for.
+      // They may not be sequential due to empty clones e.g.
+      DenseSet<unsigned> NodeCallClones;
+      for (auto *C : Node->Clones)
+        NodeCallClones.insert(C->Call.cloneNo());
+      unsigned I = 0;
+      // Now check all the function clones.
+      for (auto &FC : FuncCloneInfos) {
+        // Function clones should be sequential.
+        assert(FC.FuncClone.cloneNo() == I);
+        // Skip the first clone which got the original call.
+        // Also skip any other clones created for this Node.
+        if (++I == 1 || NodeCallClones.contains(I)) {
+          continue;
+        }
+        // Record the call clones created for this callsite in this function
+        // clone.
+        auto &CallVector = UnassignedCallClones[Node][I];
+        DenseMap<CallInfo, CallInfo> &CallMap = FC.CallMap;
+        CallInfo CallClone(Call);
+        if (auto It = CallMap.find(Call); It != CallMap.end())
+          CallClone = It->second;
+        else
+          // All but the original clone (skipped earlier) should have an entry
+          // for all calls.
+          assert(false && "Expected to find call in CallMap");
+        CallVector.push_back(CallClone);
+        // Need to do the same for all matching calls.
+        for (auto &MatchingCall : Node->MatchingCalls) {
+          CallInfo CallClone(MatchingCall);
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snehasish wrote:

This `CallClone` var shadows the one outside this scope. Can we rewrite this condition too to drop the construction and then assignment?

https://github.com/llvm/llvm-project/pull/159861