[all-commits] [llvm/llvm-project] 292478: [AMDGPU][SIFrameLowering] Use the right frame regi...

[Christudasan Devadasan via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 29247824f57e5d075dbdc320cf65e7f27fd86401
      https://github.com/llvm/llvm-project/commit/29247824f57e5d075dbdc320cf65e7f27fd86401
  Author: Christudasan Devadasan <Christudasan.Devadasan at amd.com>
  Date:   2022-12-17 (Sat, 17 Dec 2022)

  Changed paths:
    M llvm/lib/Target/AMDGPU/SIFrameLowering.cpp
    M llvm/lib/Target/AMDGPU/SIFrameLowering.h
    M llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
    M llvm/test/CodeGen/AMDGPU/GlobalISel/assert-align.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/call-outgoing-stack-args.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/localizer.ll
    M llvm/test/CodeGen/AMDGPU/abi-attribute-hints-undefined-behavior.ll
    M llvm/test/CodeGen/AMDGPU/amdpal-callable.ll
    M llvm/test/CodeGen/AMDGPU/bf16.ll
    M llvm/test/CodeGen/AMDGPU/call-graph-register-usage.ll
    M llvm/test/CodeGen/AMDGPU/call-preserved-registers.ll
    M llvm/test/CodeGen/AMDGPU/callee-frame-setup.ll
    M llvm/test/CodeGen/AMDGPU/callee-special-input-vgprs-packed.ll
    M llvm/test/CodeGen/AMDGPU/callee-special-input-vgprs.ll
    M llvm/test/CodeGen/AMDGPU/cross-block-use-is-not-abi-copy.ll
    M llvm/test/CodeGen/AMDGPU/dwarf-multi-register-use-crash.ll
    A llvm/test/CodeGen/AMDGPU/fix-frame-reg-in-custom-csr-spills.ll
    M llvm/test/CodeGen/AMDGPU/frame-setup-without-sgpr-to-vgpr-spills.ll
    M llvm/test/CodeGen/AMDGPU/gfx-call-non-gfx-func.ll
    M llvm/test/CodeGen/AMDGPU/gfx-callable-argument-types.ll
    M llvm/test/CodeGen/AMDGPU/gfx-callable-preserved-registers.ll
    M llvm/test/CodeGen/AMDGPU/gfx-callable-return-types.ll
    M llvm/test/CodeGen/AMDGPU/indirect-call.ll
    M llvm/test/CodeGen/AMDGPU/mul24-pass-ordering.ll
    M llvm/test/CodeGen/AMDGPU/need-fp-from-vgpr-spills.ll
    M llvm/test/CodeGen/AMDGPU/nested-calls.ll
    M llvm/test/CodeGen/AMDGPU/no-source-locations-in-prologue.ll
    M llvm/test/CodeGen/AMDGPU/pei-scavenge-sgpr-carry-out.mir
    M llvm/test/CodeGen/AMDGPU/pei-scavenge-sgpr-gfx9.mir
    M llvm/test/CodeGen/AMDGPU/pei-scavenge-sgpr.mir
    M llvm/test/CodeGen/AMDGPU/pei-scavenge-vgpr-spill.mir
    M llvm/test/CodeGen/AMDGPU/sgpr-spills-split-regalloc.ll
    M llvm/test/CodeGen/AMDGPU/sibling-call.ll
    M llvm/test/CodeGen/AMDGPU/spill-csr-frame-ptr-reg-copy.ll
    M llvm/test/CodeGen/AMDGPU/stack-realign.ll
    M llvm/test/CodeGen/AMDGPU/tail-call-amdgpu-gfx.ll
    M llvm/test/CodeGen/AMDGPU/tuple-allocation-failure.ll
    M llvm/test/CodeGen/AMDGPU/unstructured-cfg-def-use-issue.ll
    M llvm/test/CodeGen/AMDGPU/use_restore_frame_reg.mir
    M llvm/test/CodeGen/AMDGPU/vgpr-tuple-allocation.ll
    M llvm/test/CodeGen/AMDGPU/wave32.ll
    M llvm/test/CodeGen/AMDGPU/wwm-reserved-spill.ll

  Log Message:
  -----------
  [AMDGPU][SIFrameLowering] Use the right frame register in CSR spills

Unlike the callee-saved VGPR spill instructions emitted by
`PEI::spillCalleeSavedRegs`, the CS VGPR spills inserted during
emitPrologue/emitEpilogue require the exec bits flipping to avoid
clobbering the inactive lanes of VGPRs used for SGPR spilling.
Currently, these spill instructions are referenced from the SP at
function entry and when the callee performs a stack realignment,
they ended up getting incorrect stack offsets. Even if we try to
adjust the offsets, the FP-SP becomes a runtime entity with dynamic
stack realignment and the offsets would still be inaccurate.

To fix it, use FP as the frame base in the spill instructions
whenever the function has FP. The offsets obtained for the CS
objects would always be the right values from FP.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D134949