[PATCH] D153717: [SCCP] replace valuestate.isConstant with helper isConstant

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

This only makes a difference when the binop returns a poison result, right? I think it's unfortunate that this ends up replacing that with an undef value.

I think it would be good to introduce a new lattice value for poison, which allows us to explicitly represent this and avoid refining poison to undef. Especially in conjunction with D153718 <https://reviews.llvm.org/D153718>, which is kind of weird in we claim no undefs but the result is represented as undef.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D153717/new/

https://reviews.llvm.org/D153717