[all-commits] [llvm/llvm-project] 01bfe9: [ISEL] Canonicalize STEP_VECTOR to LHS if RHS is a...

[sdesmalen-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 01bfe9729a9812c8dcdb8f239bce23bb10637ea8
      https://github.com/llvm/llvm-project/commit/01bfe9729a9812c8dcdb8f239bce23bb10637ea8
  Author: Sander de Smalen <sander.desmalen at arm.com>
  Date:   2022-02-03 (Thu, 03 Feb 2022)

  Changed paths:
    M llvm/include/llvm/CodeGen/SelectionDAG.h
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/test/CodeGen/AArch64/active_lane_mask.ll
    M llvm/test/CodeGen/AArch64/sve-stepvector.ll

  Log Message:
  -----------
  [ISEL] Canonicalize STEP_VECTOR to LHS if RHS is a splat.

This helps recognise patterns where we're trying to match STEP_VECTOR
patterns to INDEX instructions that take a GPR for the Start/Step.

The reason for canonicalising this operation to the LHS is
because it will already be canonicalised to the LHS if the RHS
is a constant splat vector.

Reviewed By: paulwalker-arm

Differential Revision: https://reviews.llvm.org/D118459