[all-commits] [llvm/llvm-project] 7d5d06: [ARM] Fold away unnecessary CSET/CMPZ

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 7d5d063c7745672afaab9dc2e744d43093fa6062
      https://github.com/llvm/llvm-project/commit/7d5d063c7745672afaab9dc2e744d43093fa6062
  Author: David Green <david.green at arm.com>
  Date:   2021-11-27 (Sat, 27 Nov 2021)

  Changed paths:
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    M llvm/test/CodeGen/Thumb2/active_lane_mask.ll
    M llvm/test/CodeGen/Thumb2/mve-ctlz.ll
    M llvm/test/CodeGen/Thumb2/mve-cttz.ll
    M llvm/test/CodeGen/Thumb2/mve-fmas.ll
    M llvm/test/CodeGen/Thumb2/mve-fmath.ll
    M llvm/test/CodeGen/Thumb2/mve-laneinterleaving.ll
    M llvm/test/CodeGen/Thumb2/mve-pred-and.ll
    M llvm/test/CodeGen/Thumb2/mve-pred-not.ll
    M llvm/test/CodeGen/Thumb2/mve-pred-or.ll
    M llvm/test/CodeGen/Thumb2/mve-pred-shuffle.ll
    M llvm/test/CodeGen/Thumb2/mve-pred-spill.ll
    M llvm/test/CodeGen/Thumb2/mve-pred-vselect.ll
    M llvm/test/CodeGen/Thumb2/mve-pred-xor.ll
    M llvm/test/CodeGen/Thumb2/mve-vcmp.ll
    M llvm/test/CodeGen/Thumb2/mve-vcmpf.ll
    M llvm/test/CodeGen/Thumb2/mve-vcmpfr.ll
    M llvm/test/CodeGen/Thumb2/mve-vcmpfz.ll
    M llvm/test/CodeGen/Thumb2/mve-vcmpr.ll
    M llvm/test/CodeGen/Thumb2/mve-vcmpz.ll
    M llvm/test/CodeGen/Thumb2/mve-vecreduce-addpred.ll
    M llvm/test/CodeGen/Thumb2/mve-vecreduce-mlapred.ll
    M llvm/test/CodeGen/Thumb2/mve-vpsel.ll

  Log Message:
  -----------
  [ARM] Fold away unnecessary CSET/CMPZ

Codegen from expanded vector operations can end up with unnecessary
CMPZ/CSINC, of the form:
  CSXYZ A, B, C1 (CMPZ (CSINC 0, 0, C2, D), 0)

These can be converted to remove the CMPZ and CSINC, depending on the
condition.
  if C1==NE -> CSXYZ A, B, C2, D
  if C1==EQ -> CSXYZ A, B, NOT(C2), D

Differential Revision: https://reviews.llvm.org/D114013