Author: Robert Hyatt
Date: 10:51:16 11/28/03
Go up one level in this thread
On November 28, 2003 at 11:47:15, Tom Likens wrote:
>On November 28, 2003 at 11:05:12, Uri Blass wrote:
>
>>On November 28, 2003 at 10:45:54, Grzegorz Sidorowicz wrote:
>>
>>>I agree with you.
>>>But on other hand for me Crafty source code is trash :-)
>>>I don't understand it :-) and it can't help me :)))
>>>...and it is not only my opinion....it is too big, too complicated.
>>
>>
>>It could help me inspite of the fact that I did not understand most of it.
>>
>>I remember that when I implemented killer moves I look at crafty's code and
>>copied phase[ply] from it.
>>
>>I also have constants for the different phases like goodcapture and
>>firstkillermove that I probably copied from crafty(I guess that for some people
>>the fact that I copied some single words means that I have a crafty clone).
>>
>>I also looked at its evaluation and implemented smaller bonus for blocked passed
>>pawns(of course in that case I could not copy and paste but I used the same
>>idea).
>>
>>If you need another proof that movei is a crafty clone by the standard of some
>>guys then the following line is copied from crafty if I remember correctly
>>(Movei is not based on bitboards but I use bitboards for pawn structure).
>>
>>typedef unsigned __int64 BitBoard;
>>
>>The most significant proof that movei is a crafty clone is that I have the
>>following functions for bitboards(the last 2 are not copied directly from crafty
>>but are basically based on Crafty's code when I believe that the first one is
>>copied from Crafty)
>>
>>I cannot find more convincing evidence that movei is a crafty clone but I guess
>>that for some guys the evidence that I give in this post is convincing enough.
>>
>>int PopCount(register BitBoard a) {
>> register int c=0;
>>
>> while(a) {
>> c++;
>> a &= a - 1;
>> }
>> return(c);
>>}
>>
>>
>>int smallest_pow(BitBoard arg1)
>>{
>> if (arg1&65535)
>> return (smallest_power[arg1&65535]);
>>
>> if ((arg1>>16)&65535)
>> return (smallest_power[(arg1>>16)&65535]+16);
>>
>> if ((arg1>>32)&65535)
>> return (smallest_power[(arg1>>32)&65535]+32);
>> return (smallest_power[(arg1>>48)]+48);
>>}
>>
>>int biggest_pow(BitBoard arg1)
>>{
>> if (arg1>>48)
>> return biggest_power[(arg1>>48)]+48;
>> if (arg1>>32)
>> return biggest_power[(arg1>>32)]+32;
>> if (arg1>>16)
>> return biggest_power[(arg1>>16)]+16;
>> return biggest_power[arg1];
>>}
>>
>>Uri
>
>Uri,
>
>I haven't looked at Crafty's code in a long time. What are these last two
>functions used for in your program (or Crafty for that matter)?
>
>regards,
>--tom
To convert some number to a power of two. IE hash=1000000 is no good.
Crafty can take that and find the smallest power of 2 that will fit. Also
used in other places for similar reasons. Or the inverse...
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