[all-commits] [llvm/llvm-project] 5705dc: Recommit "[X86] Add `TuningPreferShiftShuffle` for...

[goldsteinn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5705dc7606556f9f4ee48835e228cb5330692d6c
      https://github.com/llvm/llvm-project/commit/5705dc7606556f9f4ee48835e228cb5330692d6c
  Author: Noah Goldstein <goldstein.w.n at gmail.com>
  Date:   2023-03-02 (Thu, 02 Mar 2023)

  Changed paths:
    M llvm/lib/Target/X86/X86.td
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/lib/Target/X86/X86TargetTransformInfo.h
    M llvm/test/CodeGen/X86/avx512-hadd-hsub.ll
    M llvm/test/CodeGen/X86/min-legal-vector-width.ll
    M llvm/test/CodeGen/X86/pr57340.ll
    M llvm/test/CodeGen/X86/shuffle-as-shifts.ll

  Log Message:
  -----------
  Recommit "[X86] Add `TuningPreferShiftShuffle` for when Shifts are preferable to shuffles." (2nd Try)

Move the opcode checks to after we have already verified we found a
valid shift instruction (`0 < ShiftAmt`) in `matchUnaryPermuteShuffle`
and `lowerShuffleAsShift`.

Reviewed By: pengfei, RKSimon

Differential Revision: https://reviews.llvm.org/D143786