[PATCH] D155940: [SimplifyCFG] Transform for merging the combination of phis in switch

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

> Such mergence may not help with other transforms (Quite a few transforms are based on two branches, but not multiple branches)

Do you have any particular issues this could cause in mind?

I think even if we don't always perform the transform, we should still express it generically, and then have a profitability heuristic on top: E.g. say that the one common predecessor must have a switch terminator. That way we can clearly separate correctness from profitability requirements.


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https://reviews.llvm.org/D155940