[PATCH] D145329: AMDGPU: Always split blocks for si_end_cf

[Nicolai Hähnle via Phabricator via llvm-commits]

nhaehnle added a comment.

I know we've talked about this in the past but I'm not a fan because it's sort of difficult to justify with a "clean" foundational semantics story.

I think a clean story would be:

- Every basic block has a canonical exec mask
- Basic blocks can have prologs and epilogs in which the canonical exec mask doesn't apply. (SI_END_CF is the prolog case.)

If SI_END_CF is split off, the new basic block containing the SI_END_CF still doesn't have a canonical exec mask that makes sense.

Yes, what I'm thinking of as a clean story would require changing the register allocator a little.


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  https://reviews.llvm.org/D145329/new/

https://reviews.llvm.org/D145329