[all-commits] [llvm/llvm-project] 76cbe6: [AMDGPU] Changes the AMDGPU_Gfx calling convention...

[Thomas Symalla via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 76cbe62262a3ccd0604599a1103ce5d38ac0164b
      https://github.com/llvm/llvm-project/commit/76cbe62262a3ccd0604599a1103ce5d38ac0164b
  Author: Thomas Symalla <thomas.symalla at amd.com>
  Date:   2021-11-04 (Thu, 04 Nov 2021)

  Changed paths:
    M llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp
    M llvm/lib/Target/AMDGPU/AMDGPUCallingConv.td
    M llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
    M llvm/lib/Target/AMDGPU/AMDGPUISelLowering.h
    M llvm/lib/Target/AMDGPU/AMDGPUInstrInfo.td
    M llvm/lib/Target/AMDGPU/AMDGPUMCInstLower.cpp
    M llvm/lib/Target/AMDGPU/SIISelLowering.cpp
    M llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
    M llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
    M llvm/lib/Target/AMDGPU/SIRegisterInfo.td
    M llvm/lib/Target/AMDGPU/SOPInstructions.td
    M llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-call-non-fixed.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-call-return-values.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-call.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-indirect-call.ll
    M llvm/test/CodeGen/AMDGPU/amdpal-callable.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/inline-asm.i128.ll
    M llvm/test/CodeGen/AMDGPU/pal-simple-indirect-call.ll
    M llvm/test/CodeGen/AMDGPU/tail-call-amdgpu-gfx.ll
    M llvm/test/CodeGen/AMDGPU/vgpr-liverange-ir.ll
    M llvm/test/CodeGen/AMDGPU/vgpr-liverange.ll
    M llvm/test/CodeGen/AMDGPU/wwm-reserved-spill.ll

  Log Message:
  -----------
  [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.

This patch changes the AMDGPU_Gfx calling convention. It defines the SGPR registers s[4:29] as callee-save and leaves some SGPRs usable for callers. The intention is to avoid unneccessary s_mov instructions for arguments the caller would otherwise save and restore in these registers.

Reviewed By: sebastian-ne

Differential Revision: https://reviews.llvm.org/D111637