[PATCH] D76153: [SimplifyCFG] try branch-to-branch simplification sooner

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

> I think the way Alive2 currently defines poison, it's safe to transform a branch to a bool select, but transforming a bool select to bitwise logic requires freeze.

Err, I meant, it's safe to transform a chain of branches to a chain of bool selects.

> Branching on poison is UB, while performing bitmath on poison will only result in poison, which is less bad i think.

The question is what happens if you have a chain of conditional branches... i.e. you're potentially transforming code that uses value in dead code to code that uses that value in live code.


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  https://reviews.llvm.org/D76153/new/

https://reviews.llvm.org/D76153