module barrel_shift
     (
         input logic [7:0] a,
         input logic [2:0] amt,
         input logic lr;
         output logic [7:0] y
     );

 logic [7:0] s0, s1;

 always_comb begin
     // right rotate
     if(lr) begin
         assign s0 = amt[0] ? {a[0], a[7:1]} : a;
         assign s1 = amt[1] ? {s0[1:0], s0[7:2]} : s0;
         assign y = amt[2] ? {s1[3:0], s[7:4]} : s1;
     end
     // left rotate
     else begin
         assign s0 = amt[0] ? {a[6:0], a[7]} : a;
         assign s1 = amt[1] ? {s0[5:0], s0[7:6]} : s0;
         assign y = amt[2] ? {s1[3:0], s1[7:4]} : s1;
     end
 end

 endmodule