[llvm] [SimplifyCFG][NFC] Improve compile time for TryToSimplifyUncondBranchFromEmptyBlock optimization. (PR #110715)

[Amara Emerson via llvm-commits]

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@@ -1182,6 +1184,10 @@ bool llvm::TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB,
   if ((!BBKillable && !BBPhisMergeable) || introduceTooManyPhiEntries(BB, Succ))
     return false;
 
+  // SuccPreds may not have been fully filled by CanRedirectPredsOfEmptyBBToSucc
+  // so finish it here.
+  SuccPreds.insert(pred_begin(Succ), pred_end(Succ));
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aemerson wrote:

Sure, I think you're right.

https://github.com/llvm/llvm-project/pull/110715