yosys/tests/arch/xilinx/opt_lut_ins.ys

read_ilang << EOF

module \top

  wire width 4 input 1 \A

  wire output 2 \O

  cell \LUT4 $0
    parameter \INIT 16'1111110011000000
    connect \I0 \A [0]
    connect \I1 \A [1]
    connect \I2 \A [2]
    connect \I3 \A [3]
    connect \O \O
  end
end

EOF

read_verilog -lib +/xilinx/cells_sim.v
equiv_opt -assert -map +/xilinx/cells_sim.v opt_lut_ins -tech xilinx

design -load postopt

select -assert-count 1 t:LUT3