Computer Chess Club Archives


Search

Terms

Messages

Subject: Reversed vs. Rotated Bitboards

Author: Sune Fischer

Date: 05:36:15 01/28/02


Hi,

I'm in the process of rewriting my entire movegen, now I'm going to need
bitboards I've decided, but it seems there are different approaches.

I found this link (it was actually dead, but google had it cached so I put it up
for a short while)
http://www.fys.ku.dk/~fischer/Temp/New%20Technology.htm

It is about reversed bitboards, the author claims it is faster than rotated:

"When taking account of memory latencies, calculating the piece attacks using
the forward and reverse bitboards can be done significantly faster due to total
independence on lookup tables and complex calculations. There are a few slight
snags with the diagonal calculations, but they are minor."


His description ("significantly faster") entrigues me (hehe) but I can't find
anything else on reversed bitboards and I've never heard of them before.

What's the catch, is there something he is not telling?

-S.





This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.