stockfish 1.8 - Eval hash gone?

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edwardyu
Posts: 34
Joined: Mon Nov 17, 2008 5:58 am

stockfish 1.8 - Eval hash gone?

Post by edwardyu » Sun Jul 04, 2010 11:08 am

I notice that stockfish 1.8 no longer has VALUE_TYPE_EVAL in tt (transposition table). Is Eval hash gone becuase it is no longer useful?

zamar
Posts: 613
Joined: Sun Jan 18, 2009 6:03 am

Re: stockfish 1.8 - Eval hash gone?

Post by zamar » Sun Jul 04, 2010 11:31 am

No. static value is now directly saved in TT. This saves some costly eval() calls and gives moderate speed-up
Joona Kiiski

edwardyu
Posts: 34
Joined: Mon Nov 17, 2008 5:58 am

Re: stockfish 1.8 - Eval hash gone?

Post by edwardyu » Sun Jul 04, 2010 12:31 pm

zamar wrote:No. static value is now directly saved in TT. This saves some costly eval() calls and gives moderate speed-up
So the tte structure documentation is not updated? :-

Code: Select all

/// The TTEntry class is the class of transposition table entries
///
/// A TTEntry needs 96 bits to be stored
///
/// bit  0-31: key
/// bit 32-63: data
/// bit 64-79: value
/// bit 80-95: depth
///
/// the 32 bits of the data field are so defined
///
/// bit  0-16: move
/// bit 17-19: not used
/// bit 20-22: value type
/// bit 23-31: generation

zamar
Posts: 613
Joined: Sun Jan 18, 2009 6:03 am

Re: stockfish 1.8 - Eval hash gone?

Post by zamar » Sun Jul 04, 2010 1:41 pm

edwardyu wrote:
zamar wrote:No. static value is now directly saved in TT. This saves some costly eval() calls and gives moderate speed-up
So the tte structure documentation is not updated? :-
Yes, I forgot to update the documentation! Thanks for pointing this out :-)
Joona Kiiski

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