[all-commits] [llvm/llvm-project] 55e760: [GlobalISel] Fold away G_BUILD_VECTOR with all ele...

[Amara Emerson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 55e760769b72eafa08e9e3f1aeb5a1ea8235baff
      https://github.com/llvm/llvm-project/commit/55e760769b72eafa08e9e3f1aeb5a1ea8235baff
  Author: Amara Emerson <amara at apple.com>
  Date:   2021-03-09 (Tue, 09 Mar 2021)

  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
    A llvm/test/CodeGen/AArch64/GlobalISel/combine-build-vector.mir

  Log Message:
  -----------
  [GlobalISel] Fold away G_BUILD_VECTOR with all elements extracted.

If every element is extracted from a G_BUILD_VECTOR, pass through the source
registers. This is different to the extract(build_vector) combine because this
one tolerates multiple users as long as they're exhaustive.

Differential Revision: https://reviews.llvm.org/D97890