[PATCH] D115247: [EarlyCSE] Retain poison flags, if program is UB if poison.

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

> Note that the code as written assumes that an instruction cannot have
> poison-generating flags and fast-math flags, but I am not sure this is
> always true. Should we add a version of andIRFlags that selectively
> allows AND'ing fast-math flags only?

Yes, I think so. Or more specifically, to only and the non-poison-generating flags. There are some FMF that are poison generating, but we don't currently treat them as such in various "poison generating" queries. If that changed in the future, we should still handle it correctly.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D115247/new/

https://reviews.llvm.org/D115247