[all-commits] [llvm/llvm-project] 2887f1: [ISel] Port AArch64 SABD and UABD to DAGCombine

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2887f1463930044a6093f111dc8eba5594144c33
      https://github.com/llvm/llvm-project/commit/2887f1463930044a6093f111dc8eba5594144c33
  Author: David Green <david.green at arm.com>
  Date:   2021-06-26 (Sat, 26 Jun 2021)

  Changed paths:
    M llvm/include/llvm/CodeGen/ISDOpcodes.h
    M llvm/include/llvm/Target/TargetSelectionDAG.td
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
    M llvm/lib/CodeGen/TargetLoweringBase.cpp
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/lib/Target/AArch64/AArch64ISelLowering.h
    M llvm/lib/Target/AArch64/AArch64InstrInfo.td

  Log Message:
  -----------
  [ISel] Port AArch64 SABD and UABD to DAGCombine

This ports the AArch64 SABD and USBD over to DAG Combine, where they can be
used by more backends (notably MVE in a follow-up patch). The matching code
has changed very little, just to handle legal operations and types
differently. It selects from (ABS (SUB (EXTEND a), (EXTEND b))), producing
a ubds/abdu which is zexted to the original type.

Differential Revision: https://reviews.llvm.org/D91937