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Subject: Re: Hashkey collisions (typical numbers)

Author: Renze Steenhuisen

Date: 08:22:56 04/07/04

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>Define collision first.
>
>(1) two different positions produce the same hash signature...
>
>(2) two different hash signatures address the same table entry...
>
>(1) should not happen with 64 bit signatures.  (2) is common and is why the
>replacement strategy is so important.

I defined collision somewhere in this thread but it is the same as (1):

from code of DarkSight which is comparable with next.c in Crafty
/********************/

    case HASH_MOVE:
        if( a tt_move is provided )
        {
            tree->stats.hashkey_requests++;
            if( provided tt_move is valid move )
                return tt_move;
            else
                tree->stats.hashkey_collisions++;
        }

/********************/

Or is there something wrong?




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