[all-commits] [llvm/llvm-project] 70b35e: [SelectionDAG] Add initial support for nneg flag o...

[Craig Topper via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 70b35ec0a81375c49482755f08afc9463210ca87
      https://github.com/llvm/llvm-project/commit/70b35ec0a81375c49482755f08afc9463210ca87
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2023-11-03 (Fri, 03 Nov 2023)

  Changed paths:
    M llvm/include/llvm/CodeGen/ISDOpcodes.h
    M llvm/include/llvm/CodeGen/SelectionDAGNodes.h
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
    M llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

  Log Message:
  -----------
  [SelectionDAG] Add initial support for nneg flag on ISD::ZERO_EXTEND. (#70872)

This adds the nneg flag to SDNodeFlags and the node printing code.
SelectionDAGBuilder will add this flag to the node if the target doesn't
prefer sign extend.

A future RISC-V patch can remove the sign extend preference from
SelectionDAGBuilder.

I've also added the flag to the DAG combine that converts
ISD::SIGN_EXTEND to ISD::ZERO_EXTEND.