[llvm] [InstrProf] Adding utility weights to BalancedPartitioning (PR #72717)

[Ellis Hoag via llvm-commits]

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@@ -933,8 +933,15 @@ std::vector<BPFunctionNode> TemporalProfTraceTy::createBPFunctionNodes(
   std::vector<BPFunctionNode> Nodes;
   for (auto &Id : FunctionIds) {
     auto &UNs = FuncGroups[Id];
-    llvm::sort(UNs);
-    UNs.erase(std::unique(UNs.begin(), UNs.end()), UNs.end());
+    llvm::sort(UNs.begin(), UNs.end(),
+               [](const UtilityNodeT &L, const UtilityNodeT &R) {
+                 return L.id < R.id;
+               });
+    UNs.erase(std::unique(UNs.begin(), UNs.end(),
+                          [](const UtilityNodeT &L, const UtilityNodeT &R) {
+                            return L.id == R.id;
+                          }),
+              UNs.end());
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ellishg wrote:

Now that we have weights, do you think it makes sense to accumulate the weights of duplicated nodes instead? For example, if we had nodes `{(A, 1), (B, 2), (B, 3), (C, 2)}` then we would end up with `{(A, 1), (B, 5), (C, 2)}`.

I imagine this might be useful for compression. If a function has many duplicate instructions, it makes sense to weight that more than other instructions that appear once.

https://github.com/llvm/llvm-project/pull/72717