[all-commits] [llvm/llvm-project] e348b0: [AArch64] Turn UZP1 with undef operand into truncate

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: e348b09bb5b1c21f6af17e3390807947a049f37e
      https://github.com/llvm/llvm-project/commit/e348b09bb5b1c21f6af17e3390807947a049f37e
  Author: David Green <david.green at arm.com>
  Date:   2022-03-04 (Fri, 04 Mar 2022)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/test/CodeGen/AArch64/insert-subvector.ll
    M llvm/test/CodeGen/AArch64/neon-perm.ll

  Log Message:
  -----------
  [AArch64] Turn UZP1 with undef operand into truncate

This turns upz1(x, undef) to concat(truncate(x), undef), as the truncate
is simpler and can often be optimized away, and it helps some of the
insert-subvector tests optimize more cleanly.

Differential Revision: https://reviews.llvm.org/D120879