`ifndef SIGN_EXTENDER_H
`define SIGN_EXTENDER_H

module sign_extender #(in_width=4, out_width=5)(
    input logic [0:0] op,
    input logic [2**in_width-1:0] val,
    output logic [2**out_width-1:0] ext_val
);
    logic [0:0] msb;
    assign msb = (val >> (in_width-1)) & 1'b1;
    always_comb begin
        if (op) begin
            ext_val = { {(2**out_width-2**in_width){msb}}, val};
        end
        if (~op) begin
            ext_val = ({{(2**out_width-2**in_width){1'b0}}, val});
        end
    end
endmodule
`endif