[all-commits] [llvm/llvm-project] 5b2626: [ARM] Flatten identity shuffles through vqdmulh nodes

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5b2626ea87f48eab011b616a96540b9e83c7ca88
      https://github.com/llvm/llvm-project/commit/5b2626ea87f48eab011b616a96540b9e83c7ca88
  Author: David Green <david.green at arm.com>
  Date:   2021-02-01 (Mon, 01 Feb 2021)

  Changed paths:
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    M llvm/test/CodeGen/Thumb2/mve-vqdmulh.ll

  Log Message:
  -----------
  [ARM] Flatten identity shuffles through vqdmulh nodes

Given a shuffle(vqdmulh(shuffle, shuffle), we can flatter the shuffles
out if they become an identity mask. This can come up during lane
interleaving, when we do that better.

Differential Revision: https://reviews.llvm.org/D94034