[PATCH] D89610: AMDGPU: Fix missing read/writelane cases to skip with exec=0

[Nicolai Hähnle via Phabricator via llvm-commits]

nhaehnle added a comment.

Adding writelane absolutely makes sense to me, but:

> Additionally, since we emit the final encoded instructions, this wasn't really matching readlane either.

:(

We have a bunch of places where we _always_ use real instructions, and presumably those are fine. But if we let real instructions creep into places where we usually use pseudos, we end up making the backend less efficient because over time, everybody will have to check for pseudos **and** reals (like in this particular case here). Can we instead add some sort of check that those real instructions aren't used during CodeGen? (The MI verifier should be able to check for this, for example.)


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  https://reviews.llvm.org/D89610/new/

https://reviews.llvm.org/D89610