Re: gnuchess bugs & java

[Xan Gregg]

[resending -- my first response didn't cc the list]

Thanks for the quick response, Mridul.

> Try with -server option , and if possible try with 1.5 heard it has a
> bit faster hotspot , better mem management , etc.
> But half the speed is quiet good I must say ! since it has no "java"
> optimizations yet :)

I tried 1.5 last night and the times got worse. This is still on the  
Mac, where 1.5 is new...  I need to try an Sun JRE. I even tried  
converting the leadz calls to 1.5's Long.numberOfLeadingZeros()  
hoping it would use the PowerPC's built-in cntlzd instruction, but  
the times got worse still. I forgot about the -server flag -- will  
try it.


> The 64 bit int's used are all unsigned in gnuchess ... java does not
> have a concept of unsigned long (actually , no concept of unsigned
> itself).
> So it is going to be interesting of how you plan to use it through  
> java.
> Book , hashing , etc will all be affected.

It hasn't been as big a problem as I expected -- I mainly just had to  
convert all the right shift operators to uses Java's unsigned right  
shift, '>>>'. A few places needed things like '& 0xff' to avoid sign  
extension. BTW, Java does have one unsigned primitive: char.

> The trick you see above is called zorbist hashing - more info here ...

Thanks for the pointers!


> > BTW, any way someone can get rid of all the spam on this list?
>
> I just rely on more agressive gmail filters ...

Actually, I was more concerned with: can the spam be kept off of the  
web archive?

xan