[all-commits] [llvm/llvm-project] a5d012: [DAG] Canonicalize non-inlane shuffle -> AND if al...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a5d0122f7591d249b14ab473c85c79defa146d38
      https://github.com/llvm/llvm-project/commit/a5d0122f7591d249b14ab473c85c79defa146d38
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2022-07-16 (Sat, 16 Jul 2022)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/lib/Target/AArch64/AArch64ISelLowering.h
    M llvm/test/CodeGen/AArch64/build-vector-extract.ll
    M llvm/test/CodeGen/AArch64/neon-bitwise-instructions.ll
    M llvm/test/CodeGen/ARM/vector-DAGCombine.ll
    M llvm/test/CodeGen/X86/sad.ll
    M llvm/test/CodeGen/X86/vector-shuffle-128-v4.ll
    M llvm/test/CodeGen/X86/vector-shuffle-512-v8.ll

  Log Message:
  -----------
  [DAG] Canonicalize non-inlane shuffle -> AND if all non-inlane referenced elements are known zero

As mentioned on D127115, this patch that attempts to recognise shuffle masks that could be simplified to a AND mask - we already have a similar transform that will fold AND -> 'clear mask' shuffle, but this patch handles cases where the referenced elements are not from the same lane indices but are known to be zero.

Differential Revision: https://reviews.llvm.org/D129150