module boothcode(ai,bi,b0,b1,b2,b3);    input[7:0] ai;    input[8:0] bi;    output[15:0] b0,b1,b2,b3;      wire[15:0] b0,b1,b2,b3;         wire[9:0] b10,b321,b543,b765;     function[9:0] booth; input a,b,c;              input[8:0] d;        case({a,b,c})                 3'b000:booth=0;          3'b001:booth=d;              3'b010:booth=d;              3'b011:booth=d<<1;           3'b100:booth=~(d<<1)+1;     3'b101:booth=~(d)+1;          3'b110:booth=~(d)+1;         3'b111:booth=0;    default:booth=0;endcase          endfunction                         assign b10=booth(ai[1],ai[0],0,bi);     assign b321=booth(ai[3],ai[2],ai[1],bi);      assign b543=booth(ai[5],ai[4],ai[3],bi);      assign b765=booth(ai[7],ai[6],ai[5],bi);          assign b0[15:10]={6{b10[9]}};     assign b0[9:0]=b10;     assign b1[15:12]={4{b321[9]}};     assign b1[11:0]=b321<<2;     assign b2[15:14]={2{b543[9]}};     assign b2[13:0]=b543<<4;      assign b3=b765<<6;     endmodule