[PATCH] D111637: [AMDGPU] Changes the AMDGPU_Gfx calling convention by making the SGPRs 4..29 callee-save. This is to avoid superfluous s_movs when executing amdgpu_gfx function calls as the callee is likely not going to change the argument values.

[Thomas Symalla via Phabricator via llvm-commits]

tsymalla added a comment.

@sebastian-ne As far as I can tell from my tests, there is no additional spilling code generated for the SGPRs `s[32:35]`. I think we should be good to go with this revision and without additionally marking these registers as callee-save. A whole lot of superfluous s_mov_b32 instructions are removed by the patch, making the waterfall loops more clean, just as intended.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111637/new/

https://reviews.llvm.org/D111637