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Subject: Re: speed question

Author: Uri Blass

Date: 08:43:17 02/20/03

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On February 20, 2003 at 11:06:28, Filip Tvrzsky wrote:

>On February 20, 2003 at 09:59:13, Uri Blass wrote:
>
>>
>>I see that it does not help me.
>>
>
>It's a pity, because this approach was really usefull for me, but you know, each
>program is a different case and what works in one doesn't work in other. It is
>hard to say why it doesn't help you. There are so many dependencies ...
>Probably this approach claims some deeper changes of your implementation in
>order to gain from it. The main idea here is IMO to restrict the memory access
>...
>
>>I had to replace in hundreds of places in my code and after all the job I have 2
>>problems from the opening position:
>>1)The code is slightly slower in the first ply(1% slower)
>>2)The bigger problem:after more than 40 seconds I start to get different number
>>of nodes(maybe I did a mistake in one of my replaces).
>>
>>Uri
>
>Of course such a change in implementation basics is very dangerous and work
>intensive operation. I hope you have some handy testing and debugging code and a
>backup of your original code too ...
>
>Filip

I have backup of my original code so I guess that I will use it.

I guess that it did not help me because of the fact that I use bits in a lot of
places in my code

for example
I have some
if (bits(m)&) in my evaluation code in order to evaluate change in the
evaluation from moves.

Maybe the problem is that I have now
if ((bits(gen_dat[i].m)&33) in my qsearch
I check for every legal move if it is a capture in order to decide if to extend
it.

I guess that all these & did my code slower.

bits(gen_dat[i].m) was already & by definition(I could save one & by having
gen_dat[i].m&(33<<24)
but in that case I do the code less clear.

I also use in a lot of cases expressions like
to(gen_dat[i].m)
Maybe the previous code gen_dat[i].m.b.to was faster.

Uri



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