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Subject: Re: I do not understand the code that is supposed to be Fritz's code

Author: Christophe Theron

Date: 10:39:16 09/04/02

Go up one level in this thread


On September 03, 2002 at 19:45:03, José Carlos wrote:

>On September 03, 2002 at 06:25:18, Uri Blass wrote:
>
>>On September 02, 2002 at 20:26:30, Vincent Diepeveen wrote:
>>
>>>On September 01, 2002 at 12:08:21, Uri Blass wrote:
>>>
>>>Uri, i posted my answer at 11:55, you answerred at 12:08.
>>>That's 13 minutes.
>>>
>>>How the HELL can you have looked up MTD in the meantime,
>>>what it is and what it is doing, and where are your experiments
>>>with MTD?
>>>
>>>For MOVEI it sure works as long are your eval is stupid.
>>>
>>>It would remove a lot of discussion about fritz here too.
>>>like the stupid comments you don't nullmove in your PV.
>>>
>>>WHICH PV DO YOU TALK ABOUT?
>>>
>>>What kind of nonsense do you do in your program.
>>>
>>>CODE PLEASE.
>>>
>>>In fritz it's very easy i bet:
>>>
>>>int mtd() {  // of course with a goto instead of a very slow function call
>>>  // hashtable probe
>>>  if( depth <= verysmalldepth ) {
>>>    lookupfasthahstable(L1 cache) // L2 cache lookup too slow of course
>>>    return(qsearch(bound)); // of course no function call but a goto, faster...
>>>  }
>>>  else if( depth < mediumdepth ) {
>>>    lookupslowhashtable(L2 cache); // main memory factor 100 slower
>>>  else // depth movei nevergets
>>>    lookupveryslowmemory(main memory);
>>>  // no returns of course in case of a truebound, because returns are too
>>>  // slow. Only a jump
>>>
>>>  if( !incheck )
>>>    TryNullmove(); // best move to make first
>>
>>I admit that I do not understand this code
>>
>>I do not know how to tell my program to look at L1 cache or L2 cache.
>>Maybe I will know better after I read the books that I ordered from amazon.
>
>  There's no instruction to tell the program to read from L1 or L2. What Vincent
>means (if I get him right) is using very small tables that fit in cache (when
>you have a small piece of data that you use very often, it's very likely to stay
>in cache).
>  Apart from this, I think the above code is simply ridiculous.
>
>  José C.


Even the comments are ridiculous...

I would not be surprised if Movei gets better than Diep in a few months. Uri has
a very scientific behaviour, Vincent... well...



    Christophe



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