[PATCH] D126895: [SLP] Phi inputs that come from an unreachable block should be undef.

[Vasileios Porpodas via Phabricator via llvm-commits]

vporpo added a comment.



> SLP does maintain program semantics: The phi value for an unreachable block doesn't matter, it can be poison, undef, 42, or anything else.

Yeah I guess you are right, If the result of the phi does not become poison when one of its inputs is a poison, then it does not change the program behavior.
I guess these SLP  poison values were a red herring.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D126895/new/

https://reviews.llvm.org/D126895