[all-commits] [llvm/llvm-project] 330921: [AMDGPU] Select AGPR in PHI operand legalization

[Stanislav Mekhanoshin via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 33092194f2cefecc75b0fd90ea21843e3550d206
      https://github.com/llvm/llvm-project/commit/33092194f2cefecc75b0fd90ea21843e3550d206
  Author: Stanislav Mekhanoshin <Stanislav.Mekhanoshin at amd.com>
  Date:   2019-10-21 (Mon, 21 Oct 2019)

  Changed paths:
    M llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
    M llvm/test/CodeGen/AMDGPU/mfma-loop.ll

  Log Message:
  -----------
  [AMDGPU] Select AGPR in PHI operand legalization

If a PHI defines AGPR legalize its operands to AGPR.
At the moment we can get an AGPR PHI with VGPR operands.
I am not aware of any problems as it seems to be handled
gracefully in RA, but this is not right anyway.

It also slightly decreases VGPR pressure in some cases
because we do not have to a copy via VGPR.

Differential Revision: https://reviews.llvm.org/D69206

llvm-svn: 375446