[llvm] [MachineOutliner] Efficient Implementation of MachineOutliner::findCandidates() (PR #90260)

[Kyungwoo Lee via llvm-commits]

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@@ -593,7 +593,11 @@ void MachineOutliner::findCandidates(
     unsigned NumDiscarded = 0;
     unsigned NumKept = 0;
 #endif
-    for (const unsigned &StartIdx : RS.StartIndices) {
+    // Sort the start indices so that we can efficiently check if candidates
+    // overlap with each other in MachineOutliner::findCandidates().
+    SmallVector<unsigned> SortedStartIndices(RS.StartIndices);
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kyulee-com wrote:

I think it's a good suggestion. Can you simply drop `const` in the outer loop so that you can sort them in place?

https://github.com/llvm/llvm-project/pull/90260