[llvm] [AMDGPU][True16][CodeGen] stop emitting spgr_lo16 from isel (PR #144819)

[Jay Foad via llvm-commits]

jayfoad wrote:

I like the overall direction of this patch, but there are things I don't understand.

Are we heading towards a deisgn where SGPR_LO16 is never used and can be removed from the compiler?

Why is legalizeOperandsVALUt16 called separately from legalizeOperands? It seems like something that should just be a part of legalizeOperands.

https://github.com/llvm/llvm-project/pull/144819