read_verilog <<EOT

module uut(
    input  [15:0] a, b,
    input         sel,
    output [15:0] res,
);
    assign res = {sel ? a + b : a - b};
endmodule

EOT

copy uut after
opt_share after
clean

show -format dot -prefix opt_share_full -notitle -color cornflowerblue uut