[PATCH] D137027: [llvm] Improve performance of programUndefinedIfUndefOrPoison

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

Not a fan of the mix of lazy and eager propagation here. I think the way you implemented the lazy isPoison check we may also run into a problem where the poison check will try to recurse past the initial instruction, and might explore a large tree that way, introducing a different compile-time problem.

Can we simply propagate poison as we visit instructions? I.e. when we visit an instruction, check whether it propagates poison and has a poison operand, if so mark it as poison itself?


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D137027