
module test1;
parameter p = 2, q = 4;
wire a, b, c;
//---------------------------------------------------------
// Code to either generate a u1.g1 instance or no instance.
// The u1.g1 instance of one of the following gates:
// (and, or, xor, xnor) is generated if
// {p,q} == {1,0}, {1,2}, {2,0}, {2,1}, {2,2}, {2, default}
//---------------------------------------------------------

or sg1(a, b, c);

if (p == 1)
if (q == 0)
begin : u1
 // If p==1 and q==0, then instantiate
and g1(a, b, c);
 // AND with hierarchical name test.u1.g1
end
else if (q == 2)
begin : u1
 // If p==1 and q==2, then instantiate
or g1(a, b, c);
 // OR with hierarchical name test.u1.g1
end
// "else" added to end "if (q == 2)" statement
else ;
 // If p==1 and q!=0 or 2, then no instantiation
else if (p == 2) begin 
case (q)
0, 1, 2:
begin : u1
 // If p==2 and q==0,1, or 2, then instantiate
xor g2(a, b, c); // XOR with hierarchical name test.u1.g1
end
default:
begin : u1
 // If p==2 and q!=0,1, or 2, then instantiate
xnor g3(a, b, c); // XNOR with hierarchical name test.u1.g1
end
endcase

if (1)
begin 
xnor g4(a, b, c); 
end


if (1)
begin : n5
xnor g5(a, b, c); 
end

end 

endmodule


module test2;
parameter p = 2, q = 4;
wire a, b, c;
//---------------------------------------------------------
// Code to either generate a u1.g1 instance or no instance.
// The u1.g1 instance of one of the following gates:
// (and, or, xor, xnor) is generated if
// {p,q} == {1,0}, {1,2}, {2,0}, {2,1}, {2,2}, {2, default}
//---------------------------------------------------------

or sg1(a, b, c);

if (p == 1)
if (q == 0)
begin : u1
 // If p==1 and q==0, then instantiate
and g1(a, b, c);
 // AND with hierarchical name test.u1.g1
end
else if (q == 2)
begin : u1
 // If p==1 and q==2, then instantiate
or g1(a, b, c);
 // OR with hierarchical name test.u1.g1
end
// "else" added to end "if (q == 2)" statement
else ;
 // If p==1 and q!=0 or 2, then no instantiation
else if (p == 2) begin : pp2
case (q)
0, 1, 2:
begin : u1
 // If p==2 and q==0,1, or 2, then instantiate
xor g2(a, b, c); // XOR with hierarchical name test.u1.g1
end
default:
begin : u1
 // If p==2 and q!=0,1, or 2, then instantiate
xnor g3(a, b, c); // XNOR with hierarchical name test.u1.g1
end
endcase

if (1)
begin 
xnor g4(a, b, c); 
end


if (1)
begin : n5
xnor g5(a, b, c); 
end

end 

endmodule