/// <summary>
/// And function for FDD's.
/// </summary>
/// <param name="u1">left side of the expression</param>
/// <param name="u2">right side of the expression</param>
/// <returns>a new BDD where u1 and u2 are bitwise and'ed</returns>
public static Bdd And(Fdd u1, Fdd u2)
{
int u1Size = Size(u1);
int u2Size = Size(u2);
int MinSize = Min(u1Size, u2Size);
Bdd result = new Bdd(false);
for (int i = 0; i < MinSize; i++)
{
result = Kernel.Or(result, Kernel.And(new Bdd(u1.Var + i), new Bdd(u2.Var + i)));
}
if (u1Size != u2Size)
{
if (u1Size > u2Size) //you reach this state when 2 Fdds does not have the same number
{ //of bits. What happens is then the smallest get buffered with 0's
for (int i = MinSize; i < u1Size; i++)
{
result = Kernel.Or(result, Kernel.And(new Bdd(u1.Var + i), new Bdd(false)));
}
}
else
{
for (int i = MinSize; i < u2Size; i++)
{
result = Kernel.Or(result, Kernel.And(new Bdd(false), new Bdd(u2.Var + i)));
}
}
}
return(result);
}
static void Main(string[] args)
{
/*
* BDDHash ht = new BDDHash();
* BddNode b = new BddNode(3, 1, 0);
* BddNode b1 = new BddNode(2, 1, 1);
* BddNode b2 = new BddNode(16, 0, 0);
* int key = ht.GenerateKey(b);
* int key1 = ht.GenerateKey(b1);
* int key2 = ht.GenerateKey(b2);
* Console.WriteLine(key.ToString());
*
* Console.WriteLine(ht.count.ToString()); // test count for Add
*
* ht.Add(key, b); // test Add
* ht.Add(key1, b1); // test Add
* ht.Add(key2, b2); // test Add
*
* Console.WriteLine(ht.count.ToString()); // test count for after Add
* ht.Clear();
* Console.WriteLine(ht.count.ToString()); // test for Clear()
* */
Bdd result = new Bdd(true);
BDD.Setup();
{
Bdd a = new Bdd(1);
Bdd b = new Bdd(2);
Bdd c = new Bdd(3);
Bdd d = new Bdd(4);
Bdd e;
e = BDD.Equal(a, b);
Console.WriteLine(BDD.TCount().ToString());
c = BDD.Equal(c, d);
Console.WriteLine(BDD.TCount().ToString());
result = BDD.And(e, c);
result = BDD.Or(result, e);
}
Console.WriteLine(BDD.TCount().ToString());
BddSerializer.Serialize(result, "foo");
}
public Bdd execute()
{
// Calls specific methods from Kernel
Bdd l = left.execute();
Bdd r = right.execute();
Bdd result = new Bdd(false);
switch (op)
{
case Kind.DIS:
result = BDD.Or(l, r);
break;
case Kind.CON:
result = BDD.And(l, r);
break;
case Kind.BIMP:
result = BDD.Equal(l, r);
break;
case Kind.NAND:
result = BDD.Nand(l, r);
break;
case Kind.XOR:
result = BDD.Xor(l, r);
break;
case Kind.NOR:
result = BDD.Nor(l, r);
break;
case Kind.NOT:
result = BDD.Not(r);
break;
}
l.Dispose(); //forced garbage collection
r.Dispose();
return(result);
}
/// <summary>
/// Creates a hard binding sort of like an fdd restrict.
/// Difference is that the binding will persist no matter
/// what changes is later added.
/// </summary>
/// <param name="fdd">the Fdd to create a binding on</param>
/// <param name="value">the constant number that is assigned to the Fdd.</param>
/// <returns></returns>
public static Bdd Equal(Fdd fdd, int value)
{
if (Log2(value) > FddDictionary[fdd.Var]) //value larger than fdd can hold.
{
return(new Bdd(false));
}
bool[] b = ToBitPattern(value, Size(fdd));
Bdd result = new Bdd(true);
for (int i = 0; i < b.Length; i++)
{
if (b[i])
{
result = Kernel.And(result, new Bdd(fdd.Var + i));
}
else
{
result = Kernel.And(result, Kernel.Not(new Bdd(fdd.Var + i)));
}
}
return(result);
}
/// <summary>
/// Conjunction of two Bdds
/// </summary>
/// <param name="l">Left Bdd</param>
/// <param name="r">Right Bdd</param>
/// <returns>Resulting Bdd</returns>
public static Bdd operator &(Bdd l, Bdd r)
{
return(Kernel.And(l, r));
}