[all-commits] [llvm/llvm-project] 1a2e90: [SVE][CodeGen] Add patterns for ADD/SUB + element ...

[kmclaughlin-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 1a2e90199f83e7e3a7267b8fa9715d87ed5b2f88
      https://github.com/llvm/llvm-project/commit/1a2e90199f83e7e3a7267b8fa9715d87ed5b2f88
  Author: Kerry McLaughlin <kerry.mclaughlin at arm.com>
  Date:   2021-10-13 (Wed, 13 Oct 2021)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/lib/Target/AArch64/AArch64.td
    M llvm/lib/Target/AArch64/AArch64InstrInfo.td
    M llvm/lib/Target/AArch64/AArch64SVEInstrInfo.td
    M llvm/lib/Target/AArch64/AArch64Subtarget.h
    M llvm/lib/Target/AArch64/SVEInstrFormats.td
    M llvm/test/CodeGen/AArch64/named-vector-shuffles-sve.ll
    M llvm/test/CodeGen/AArch64/sve-extract-fixed-vector.ll
    M llvm/test/CodeGen/AArch64/sve-gep.ll
    M llvm/test/CodeGen/AArch64/sve-insert-element.ll
    M llvm/test/CodeGen/AArch64/sve-insert-vector.ll
    M llvm/test/CodeGen/AArch64/sve-intrinsics-counting-elems.ll
    M llvm/test/CodeGen/AArch64/sve-split-extract-elt.ll
    M llvm/test/CodeGen/AArch64/sve-split-insert-elt.ll
    M llvm/test/CodeGen/AArch64/sve-stepvector.ll
    A llvm/test/CodeGen/AArch64/sve-vl-arith.ll

  Log Message:
  -----------
  [SVE][CodeGen] Add patterns for ADD/SUB + element count

This patch adds patterns to match the following with INC/DEC:
 - @llvm.aarch64.sve.cnt[b|h|w|d] intrinsics + ADD/SUB
 - vscale + ADD/SUB

For some implementations of SVE, INC/DEC VL is not as cheap as ADD/SUB and
so this behaviour is guarded by the "use-scalar-inc-vl" feature flag, which for SVE
is off by default. There are no known issues with SVE2, so this feature is
enabled by default when targeting SVE2.

Reviewed By: david-arm

Differential Revision: https://reviews.llvm.org/D111441