VB.NET Question

[EnigmaticCam]

Ok, so I'm trying to write a chess engine in VB.Net 2005. Yes, I know it's not the greatest environment to make a chess engine, but it's just for fun.

Anyways, I'm using bitboards to help calculate moves as quickly as possible. If you're not familiar with bitboards, they are basically very large numbers that are binary representations of the board in a current position.

My problem is that a bitboard has to hold a value from 2^0 to 2^64-1 (which I can do just fine storing it in an unsigned long), yet when I attempt to AND any number equal to or greater than 2^63, I get an overflow exception. Basically, the AND bitwise operator is limited to numbers lower than 2^63, and I can't find an alternative.

Anybody here who can help me out?

 

[AltF4]

If you're just doing a bitwise AND, you could split the number into two smaller numbers. Compute the AND separately, then join them again.

It's kind of a kludge, but it should do the trick. It would work like...

10101000 10101101 (binary) = 43,181 (decimal)
AND
10010100 10001101 (binary) = 38,029 (decimal)

split into...

10101000 = 168 10101101 = 173
AND AND
10010100 = 148 10001101 = 141
EQUALS EQUALS
10000000 = 128 10001101 = 141

Then combine again...

10000000 10001101 = 32909

 

[EnigmaticCam]

I thought about splitting it like that. The key to a strong chess engine is being able to calculate these moves quickly, and I was hoping if there was some more direct approach with less extra conversion than necessary. If there isn't, then that's exactly what I will have to do, split the bitboard.

 

[AltF4]

Like I said, it's a kludge. But I'm not familiar with VB.NET, so I can't tell you what functions are available to you. Just general programming tips.