[PATCH] D126389: [AMDGPU] Improve codegen of extractelement/insertelement in some cases

[Jay Foad via Phabricator via llvm-commits]

foad added a comment.

In D126389#3538346 <https://reviews.llvm.org/D126389#3538346>, @rampitec wrote:

> Any performance numbers? The 8 element case was driven by a specific customer program and the performance of the cmp/select was better than movrel.

I don't know why that would be. Maybe the performance characteristics are different on GFX10+ compared to GFX9.

Also on GFX10+ sgpr usage does not affect occupancy, so perhaps the heuristic could be tweaked to make it more likely to use s_movrel (not v_movrel) on GFX10+.


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https://reviews.llvm.org/D126389