[PATCH] D106317: [SimplifyCFG] performBranchToCommonDestFolding(): form sudo-LCSSA before cloning instructions (PR51125)

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

In D106317#2888819 <https://reviews.llvm.org/D106317#2888819>, @jdoerfert wrote:

> It seems odd that we need to "prepare the IR" so late.

Well, i view this part of `CloneInstructionsIntoPredecessorBlockAndUpdateSSAUses()`, just done before the CFG changes.

> At first glance, only looking at pr51125, it seems we treat uses in PHIs as uses of the phi block and not the predecessor (edge). Is that the problem?

"as uses *in* the phi block" you mean? I'm afraid i'm not really seeing it?


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