[all-commits] [llvm/llvm-project] 1ba8f4: [AArch64] Move v4i8 concat load lowering to a comb...

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 1ba8f4f67dcf52cf628caa6e84c3526e936fa6b4
      https://github.com/llvm/llvm-project/commit/1ba8f4f67dcf52cf628caa6e84c3526e936fa6b4
  Author: David Green <david.green at arm.com>
  Date:   2022-04-14 (Thu, 14 Apr 2022)

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

  Log Message:
  -----------
  [AArch64] Move v4i8 concat load lowering to a combine.

The existing code was not updating the uses of loads that it recreated,
leading to incorrect chains which could break the ordering between
nodes. This moves the code to a combine instead, and makes sure we
update the chain references. This does mean it happens earlier -
potentially before the concats are simplified. This can lead to
inefficiencies in the codegen, which will be fixed in followups.