TWO BIT COMPARATOR:- 

(one bit wide)

module comp1 (gt,eq,lt,a,b);
input a,b;
output gt,eq,lt;
not G1(abar,a);
not G2(bbar,b);
and G3(gt,a,bbar);
and G4(lt,abar,b);
xnor G5(eq,a,b);
endmodule

TEST BENCH:- 

module comp1_tb();

reg a,b;
wire gt,eq,lt;
comp1 dut (gt,eq,lt,a,b);
initial
begin
repeat(20)
begin
a=$random;
b=$random;
#1;
$display(a,b,":",gt,eq,lt);
end
end
endmodule