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Subject: Re: Crafty and NUMA

Author: Anthony Cozzie

Date: 16:23:46 09/03/03

Go up one level in this thread


On September 03, 2003 at 11:53:58, Robert Hyatt wrote:

>On September 03, 2003 at 08:12:55, Uri Blass wrote:
>
>>On September 03, 2003 at 02:24:00, Gian-Carlo Pascutto wrote:
>>
>>>On September 02, 2003 at 22:34:49, Robert Hyatt wrote:
>>>
>>>>>Been working a year fulltime now :)
>>>>>
>>>>
>>>>So?  It took you over a year to get your parallel search working.  It took
>>>>me weeks.
>>>>
>>>>:)
>>>
>>>In all fairness, he did a full DTS implementation, including rewriting the
>>>program to a nonrecursive search, while you took an easy way out.
>>
>>I do not understand the need for non recursive search.
>>
>>I think that non recursive search simply limit your possibilities for future
>>developement because the code is ugly and you need to write almost the same
>>function again and again.
>
>
>
>You don't do recursive calls, instead you have a loop that increments ply
>and goes back to the top for the next level of the tree.  The reason this is
>needed is that you want to be able to see the _entire_ tree, and tell a
>processor to start work _there_ (at some specific ply where you are pretty
>certain all moves need to be searched.)  WIth a recursive search, this is
>very difficult to do.  It is easy to split the tree at the current ply, but
>it is _very_ difficult to split somewhere else.
>
>
>>
>>If you want to change something in the search rules then you need to change your
>>program in a lot of places.
>
>No.  rather than recursive calls, you execute the same loop over and over, once
>for each ply of the search...
>
>
>>
>>I guess that you need to write code for every possible depth that you get and in
>>order to let your self to do extensions you need to write code for
>>depth 10,depth 10 after one extension,depth 10 after 2 extensions, and you also
>>need to limit the number of extensions at specific depth.
>>
>>You also limit your possibilities to extend because
>>you cannot decide to extend more than one ply without modifying your code.
>>
>><snipped>
>>>
>>>Diep's parallel performance does seem to be better than what you and I are
>>>getting.
>>
>>I have no idea about Diep's parallel performance.
>>I do not know about a single game of Diep on the new machine and I guess that we
>>need to wait for november to see its performance.
>>
>>Uri


wouldn't it be easier to simply put all your recursive variables into some huge
struct and essentially manage the stack yourself (while still traversing it with
a recursive function over a loop) ?



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