[all-commits] [llvm/llvm-project] c3bf6d: [X86] Fold PSHUF(VSHIFT(X, Y)) -> VSHIFT(PSHUF(X), Y)

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: c3bf6d20ac306b829dc99939b3a8f9487f7f1c9a
      https://github.com/llvm/llvm-project/commit/c3bf6d20ac306b829dc99939b3a8f9487f7f1c9a
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2023-04-22 (Sat, 22 Apr 2023)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/abds-vector-128.ll
    M llvm/test/CodeGen/X86/abdu-vector-128.ll
    M llvm/test/CodeGen/X86/avx512-cmp.ll
    M llvm/test/CodeGen/X86/combine-abs.ll
    M llvm/test/CodeGen/X86/combine-mul.ll
    M llvm/test/CodeGen/X86/combine-ptest.ll
    M llvm/test/CodeGen/X86/combine-sdiv.ll
    M llvm/test/CodeGen/X86/freeze-binary.ll
    M llvm/test/CodeGen/X86/icmp-abs-C-vec.ll
    M llvm/test/CodeGen/X86/icmp-pow2-logic-npow2.ll
    M llvm/test/CodeGen/X86/known-signbits-vector.ll
    M llvm/test/CodeGen/X86/packss.ll
    M llvm/test/CodeGen/X86/pr32907.ll
    M llvm/test/CodeGen/X86/promote-cmp.ll
    M llvm/test/CodeGen/X86/rotate_vec.ll
    M llvm/test/CodeGen/X86/sadd_sat_vec.ll
    M llvm/test/CodeGen/X86/sdiv_fix_sat.ll
    M llvm/test/CodeGen/X86/select-sra.ll
    M llvm/test/CodeGen/X86/shift-logic.ll
    M llvm/test/CodeGen/X86/shrink_vmul.ll
    M llvm/test/CodeGen/X86/shuffle-of-shift.ll
    M llvm/test/CodeGen/X86/ssub_sat_vec.ll
    M llvm/test/CodeGen/X86/vec_shift5.ll
    M llvm/test/CodeGen/X86/vector-bo-select.ll
    M llvm/test/CodeGen/X86/vector-sext.ll
    M llvm/test/CodeGen/X86/vector-shift-ashr-128.ll
    M llvm/test/CodeGen/X86/vector-shift-ashr-sub128.ll
    M llvm/test/CodeGen/X86/vector-shift-lshr-sub128.ll
    M llvm/test/CodeGen/X86/vector-shift-shl-sub128.ll
    M llvm/test/CodeGen/X86/vector_splat-const-shift-of-constmasked.ll
    M llvm/test/CodeGen/X86/viabs.ll
    M llvm/test/CodeGen/X86/vselect-zero.ll
    M llvm/test/CodeGen/X86/vselect.ll
    M llvm/test/CodeGen/X86/vshift-3.ll
    M llvm/test/CodeGen/X86/vsplit-and.ll

  Log Message:
  -----------
  [X86] Fold PSHUF(VSHIFT(X,Y)) -> VSHIFT(PSHUF(X),Y)

PSHUFD/PSHUFLW/PSHUFHW can act as a vector move / folded load, notably helping simplify pre-AVX cases in particular.

This is a much milder alternative to refactoring canonicalizeShuffleWithBinOps to support SSE shifts nodes.