[llvm] StructurizeCFG: Optimize phi insertion during ssa reconstruction (PR #101301)

[Matt Arsenault via llvm-commits]

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@@ -256,6 +256,10 @@ class StructurizeCFG {
   BBPhiMap DeletedPhis;
   BB2BBVecMap AddedPhis;
 
+  SmallVector<BBValueVector> BBValuesPool;
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arsenm wrote:

Document what BBValuesPool is 

https://github.com/llvm/llvm-project/pull/101301