[Mlir-commits] [mlir] [mlir] Avoid rewriting unreachable blocks in the greedy driver (PR #225814)

[Mehdi Amini]

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joker-eph wrote:

> But when you already know that your greedy pattern rewrite never sees unstructured control flow (or multiple blocks per region), you could skip this walk entire and don't need the reachability bookkeeping. 

I'm skeptical of those approaches, though. This seems like design smell to me, kind of thing to keep as a last resort. 

PTAL though, there shouldn't be a full IR walk anymore. Measurements don't show impact beyond noise right now (unless very larges Unstructured CFGs )

https://github.com/llvm/llvm-project/pull/225814