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Subject: Re: HashTable upper_bound worthless ?

Author: Larry Griffiths

Date: 19:03:21 02/14/01

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On February 14, 2001 at 16:38:57, David Rasmussen wrote:

>On February 14, 2001 at 12:37:52, Larry Griffiths wrote:
>
>>
>>My program goes 17 plys in 18 seconds without the hash table,
>>and 19 plys in 6 seconds with the hash table.
>>
>
>
>You still have a bug then. If you search 17 plys in 18 seconds without the HT on
>fine70, you should be searching at least 25 plys in 1 second _with_ the HT.

I agree with you David.  It may be that the positions do not distribute very
well with the hash-keys being generated.  At least I seem to have a hash table
that works somewhat without giving away pieces.  I think I had been up to 25
plys before with my old hash table, but I found a bug in my code where this
statement...

   if((pHE->Status&(hesValid|WhoIsToMove)))

should have been...

   if((pHE->Status&(hesValid|WhoIsToMove))==(hesValid|WhoIsToMove))

The incorrect statement was saying if either bit was on then use the hash entry
instead of saying if BOTH bits are on, use the hash entry.

I will be running a lot of tests to see how I can improve on this hash table.

Larry.



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