[PATCH] D56242: Elevate instructions across if-else blocks for better constant propagation

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

In D56242#1352245 <https://reviews.llvm.org/D56242#1352245>, @efriedma wrote:

> Please include a few simpler testcases, so it's more obvious what the pass actually does.  As far as I can tell, this is similar to InstCombiner::foldOpIntoPhi, but it's a lot more aggressive?


I feel like pointing out that a "separate IR hoisting pass" has been brought up several times in previous reviews, as the means to potentially drop some stuff out of instcombine e.g.

> It looks like this increases codesize, in general; do we need some limit to prevent codesize from exploding in general?  Should that limit depend on optsize?




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  https://reviews.llvm.org/D56242/new/

https://reviews.llvm.org/D56242