[all-commits] [llvm/llvm-project] b3afad: [GlobalISel] Add a `X, Y = G_UNMERGE(G_ZEXT Z)` ->...

[qcolombet via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: b3afad046301d8bb1f4471aceaad704b87de3a69
      https://github.com/llvm/llvm-project/commit/b3afad046301d8bb1f4471aceaad704b87de3a69
  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/sdiv.i32.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/shl-ext-reduce.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/srem.i32.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/udiv.i32.ll
    M llvm/test/CodeGen/AMDGPU/GlobalISel/urem.i32.ll

  Log Message:
  -----------
  [GlobalISel] Add a `X, Y = G_UNMERGE(G_ZEXT Z)` -> X = G_ZEXT Z; Y = 0 combine

Add a combiner helper to transform unmerge of zext into one zext and
a constant 0

Differential Revision: https://reviews.llvm.org/D87427