[PATCH] D37034: Insert IMPLICIT_DEFS for undef uses in tail merging

[Matthias Braun via Phabricator via llvm-commits]

MatzeB added a comment.

Uh this is an old commit... Yes Albertos example does not look quite right, though I'm not sure how we would get there. The code does seem to compute liveness before inserting implicit defs (variants of `LiveRegs.addLiveOuts(*Pred); LiveRegs.stepBackward() ... if (LiveRegs.available(...)) continue; BuildMI(IMPLICIT_DEF)`) I would expect that when using `stepBackward()` over the jump instruction that uses r2 that it is marked as live and no IMPLICIT_DEF is inserted. If you want to debug this, you should probably start checking the computed liveness information there...


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  rL LLVM

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  https://reviews.llvm.org/D37034/new/

https://reviews.llvm.org/D37034