[all-commits] [llvm/llvm-project] d6fdbb: AMDGPU: Add second emergency slot for SGPR to vmem...

[Matt Arsenault via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d6fdbbcace0b51c0096c5dbab6afb6449da21524
      https://github.com/llvm/llvm-project/commit/d6fdbbcace0b51c0096c5dbab6afb6449da21524
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2022-02-02 (Wed, 02 Feb 2022)

  Changed paths:
    M llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
    M llvm/lib/Target/AMDGPU/SILowerSGPRSpills.cpp
    M llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
    M llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
    A llvm/test/CodeGen/AMDGPU/sgpr-spill-vmem-large-frame.mir

  Log Message:
  -----------
  AMDGPU: Add second emergency slot for SGPR to vmem for large frames

In a future change, we will sometimes use a VGPR offset for doing
spills to memory, in which case we need 2 free VGPRs to do the SGPR
spill. In most cases we could spill the VGPR along with the SGPR being
spilled, but we don't have any free lanes for SGPR_1024 in wave32 so
we could still potentially need a second scavenging slot.