[all-commits] [llvm/llvm-project] 78d455: GlobalISel: Add combine to narrow G_LSHR

[Matt Arsenault via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 78d455adf02c985a78740a378e6b3a5e8665623d
      https://github.com/llvm/llvm-project/commit/78d455adf02c985a78740a378e6b3a5e8665623d
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2020-02-17 (Mon, 17 Feb 2020)

  Changed paths:
    M llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
    M llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
    M llvm/lib/Target/AMDGPU/AMDGPUPreLegalizerCombiner.cpp
    A llvm/test/CodeGen/AMDGPU/GlobalISel/combine-lshr-narrow.mir

  Log Message:
  -----------
  GlobalISel: Add combine to narrow G_LSHR

Produce an unmerge to a narrower type and introduce a narrower shift
if needed. I wasn't sure if there was a better way to parameterize the
target's preferred shift type for the GICombineRule, so manually call
the combine helper.