[all-commits] [llvm/llvm-project] 79ce9b: CodeGen: Don't drop AA metadata when splitting Mac...

[Matt Arsenault via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 79ce9bb3803998fc2a20ce1c88392cf292f35f92
      https://github.com/llvm/llvm-project/commit/79ce9bb3803998fc2a20ce1c88392cf292f35f92
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2020-08-20 (Thu, 20 Aug 2020)

  Changed paths:
    M llvm/lib/CodeGen/MachineFunction.cpp
    M llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
    M llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-load-memory-metadata.mir
    A llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-split-scalar-load-metadata.mir

  Log Message:
  -----------
  CodeGen: Don't drop AA metadata when splitting MachineMemOperands

Assuming this is used to split a memory access into smaller pieces,
the new access should still have the same aliasing properties as the
original memory access. As far as I can tell, this wasn't
intentionally dropped. It may be necessary to drop this if you are
moving the operand outside of the bounds of the original object in
such a way that it may alias another IR object, but I don't think any
of the existing users are doing this. Some of the uses widen into
unused alignment padding, which I think is OK.