Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Non Recursive Search

Author: rasjid chan

Date: 11:05:42 04/15/04

Go up one level in this thread


On April 15, 2004 at 12:22:43, Stefano Gemma wrote:

>On April 15, 2004 at 05:01:54, rasjid chan wrote:
>
>>After reading the recent post on non-recursive search, I decided to
>>implement it. My guess is that maybe search function call overhead
>>may be too high as I have a host of local variables that cannot be reduced.
>>
>>My approach is direct and simple, an attempt to immitate recursion by
>>creating my own search stack and managing it instead of allowing C function
>[...]
>
>In my old program Drago for Dos (1993's sources are at www.linformatica.com), i
>don't use recursive search. The same was for Raffaela. Both are written in
>assembly. I use a fixed area of memory to old variables for any node (it is
>something like an array of struct, but in assembly). Debugging a non-recursive
>engine in assembly, with a lot of conditional jump was very hard. My last
>engine, Freccia, don't use non-recursive search but still i don't use stack for
>variables but the old array of struct. I think this is the better way to do, in
>my program. Debugging is easyer and i can preset some fixed constant depending
>on the node depth.
>
>Ciao!!!
>
>Stefano Gemma

To do non-recursive search in assembly would be too tough for me, even with
easy C the debugging can be tricky.

I am not sure I know or use programming terms / naming correct. What I mean
by stack is my data of array of search_stack_struct type which I create.
Then make/unmake a move becomes ++ply, ++ps, --ply, --ps
where ps is a pointer to my search_stack_struct. So using this pointer ps,
I store / restore my alpha,depth,pointer to current move made / first or
last move in my move list, etc. In this way and with care we can try
non-recursive search and I think there should not be reasons why it cannot
be made better than recursive search.

Best Regards
Rasjid






This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.