[all-commits] [llvm/llvm-project] 4c0fc4: AMDGPU: Mark scalar loads as rematerializable

[Matt Arsenault via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4c0fc4841b43aa3d6efb76cf0030c46cb0cc9a3e
      https://github.com/llvm/llvm-project/commit/4c0fc4841b43aa3d6efb76cf0030c46cb0cc9a3e
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2023-06-09 (Fri, 09 Jun 2023)

  Changed paths:
    M llvm/lib/Target/AMDGPU/SMInstructions.td
    A llvm/test/CodeGen/AMDGPU/remat-smrd.mir

  Log Message:
  -----------
  AMDGPU: Mark scalar loads as rematerializable

This should be true, but this is useless as is. The rematerialization
logic only permits rematerialize with constant physical register uses,
so non-constant physregs or virtual register uses (the case that
really matters) are not rematerialized. Add the tests which shows
nothing happens, but should in the future.

Also, all loads should really be rematerializable so in the future
this should apply to all the other kinds.