[all-commits] [llvm/llvm-project] d23211: [GlobalISel] Add `X, Y<dead> = G_UNMERGE Z` -> X = ...

[qcolombet via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: d2321129bda712a0e7ee222c7cb6a62e5ca5b6f4
      https://github.com/llvm/llvm-project/commit/d2321129bda712a0e7ee222c7cb6a62e5ca5b6f4
  Author: Quentin Colombet <qcolombet at apple.com>
  Date:   2020-09-14 (Mon, 14 Sep 2020)

  Changed paths:
    M llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
    M llvm/include/llvm/Target/GlobalISel/Combine.td
    M llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
    M llvm/test/CodeGen/AArch64/GlobalISel/combine-unmerge.mir
    M llvm/test/CodeGen/AMDGPU/GlobalISel/combine-shl-narrow.mir
    M llvm/test/CodeGen/AMDGPU/GlobalISel/legalize-llvm.amdgcn.image.store.2d.d16.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.s.buffer.load.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/postlegalizercombiner-select.mir
    M llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-amdgcn.s.buffer.load.ll

  Log Message:
  -----------
  [GlobalISel] Add `X,Y<dead> = G_UNMERGE Z` -> X = G_TRUNC Z

Add a combiner helper that replaces G_UNMERGE where all the destination lanes
are dead except the first one with a G_TRUNC.

Differential Revision: https://reviews.llvm.org/D87174