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cdani wrote:

Dann Corbit wrote:

retep1 wrote:I followed the steps you specified.
Unfortunately it doesn't work - neither in the Fritz 15 GUI nor in Aquarium 2017 - although the hash-file is created, but after loading the hashfile the analysis starts again at depth 0 - not 40 where I saved the analysis.
What could be wrong here? Any idea?

Nothing is wrong.
Look at how long it takes to analyze the same position compared to the first time.

The engine has the old hash values, but it still has to perform the search.

Thanks for explaining! This has given me an idea, to save also the whole state of the engine, so to allow it to recover the search from the point it was. I will try to see if is feasible in Andscacs.

Milos wrote:This has given me an idea, to save also the whole state of the engine, so to allow it to recover the search from the point it was. I will try to see if is feasible in Andscacs.

cdani wrote: And state of pawn hash, refutation tables, other tables, some globals... The triviality depend on how is done the engine.
Of course if I had known from the begin that I will want to do it, I had done some things differently.
Also think that probably, at least that I know, no engine has done this. Maybe just no programmer has thought about it.

Rodolfo Leoni wrote: And what about an option of using hashes as book (min depth X)? Just a flash I had one minute ago. One lets the engine thinting at a position, goes to work, gets home, kisses his wife and... let us see how it works as book! Wouldn't be nice?

cdani wrote:

Rodolfo Leoni wrote: And what about an option of using hashes as book (min depth X)? Just a flash I had one minute ago. One lets the engine thinting at a position, goes to work, gets home, kisses his wife and... let us see how it works as book! Wouldn't be nice?

If I understand well, what you propose can be done simply by loading a hash/engine state, and let the engine play using it. So it's already doable with those versions.

cdani wrote:If someone wants to propose this change for official Stockfish, please go ahead. I don't plan to do it anytime soon. You can take this code or make your own version, as you wish.

Also I forgot to tell that in this code there is the small change proposed by Hgm about maintaining the age during infinite analysis session. As the other change, you can submit it to official Stockfish if you want if someone has not already done it.

Rodolfo Leoni wrote:

cdani wrote:

Rodolfo Leoni wrote: And what about an option of using hashes as book (min depth X)? Just a flash I had one minute ago. One lets the engine thinting at a position, goes to work, gets home, kisses his wife and... let us see how it works as book! Wouldn't be nice?

If I understand well, what you propose can be done simply by loading a hash/engine state, and let the engine play using it. So it's already doable with those versions.

Yes, with a tuneable hash min depth for using it as a book. Example, we have an hash file which reaches depth 40. We set the UCI option "Hash as a book depth 25" and engine will play best moves in the hash for 15 plies. Of course if opponent goes "out of hashes" then Andscacs should perform a normal search.

Your opinion?

    tte = TT.probe(posKey);
    if (tte)
    {
        rtte = *tte;
        tte = &rtte;
    }

    if (tte && (    (tte->move() && !pos.move_is_pseudo_legal(tte->move()))
                    || (!inCheck && (tte->static_value() == VALUE_NONE || tte->static_value_margin() == VALUE_NONE))
                    || ( inCheck && (tte->static_value() != VALUE_NONE || tte->static_value_margin() != VALUE_NONE)) ))
        tte = NULL;

    ttMove = Root ? Rml[0].pv[0] : tte ? tte->move() : MOVE_NONE;

    // At PV nodes we check for exact scores, while at non-PV nodes we check for
    // a fail high/low. Biggest advantage at probing at PV nodes is to have a
    // smooth experience in analysis mode.
    if (   !Root
            &&  tte
            &&  tte->value() != VALUE_NONE
            && &#40;PvNode ? tte->depth&#40;) >= depth && tte->type&#40;) == VALUE_TYPE_EXACT && tte->value&#40;) > alpha && tte->value&#40;) < beta
                &#58; ok_to_use_TT&#40;tte, depth, beta, ss->ply&#41;) )
    &#123;
        TT.store&#40;posKey, tte->value&#40;), tte->type&#40;), tte->depth&#40;), tte->move&#40;), tte->static_value&#40;), tte->static_value_margin&#40;));
        ss->currentMove = ttMove; // Can be MOVE_NONE
        if &#40;tte->value&#40;) >= VALUE_MATE_IN_PLY_MAX&#41;
            ss->mateKiller = ttMove;
        if (    tte->value&#40;) >= beta
                &&  ttMove
                && !pos.move_is_capture_or_promotion&#40;ttMove&#41;
                &&  ttMove != ss->killers&#91;0&#93;)
        &#123;
            ss->killers&#91;1&#93; = ss->killers&#91;0&#93;;
            ss->killers&#91;0&#93; = ttMove;
        &#125;
        return value_from_tt&#40;tte->value&#40;), ss->ply&#41;;
    &#125;

Dann Corbit wrote: Engines already have code to play hash moves instantly.
Basically the requirement is the hash hit has to pass some simple tests to ensure it is the proper position, and then it also has to be deep enough.

Here is the code from Sting85 that probes the hash and returns the hash move if all the tests pass muster.

Code: Select all

    tte = TT.probe(posKey);
    if (tte)
    {
        rtte = *tte;
        tte = &rtte;
    }

    if (tte && (    (tte->move() && !pos.move_is_pseudo_legal(tte->move()))
                    || (!inCheck && (tte->static_value() == VALUE_NONE || tte->static_value_margin() == VALUE_NONE))
                    || ( inCheck && (tte->static_value() != VALUE_NONE || tte->static_value_margin() != VALUE_NONE)) ))
        tte = NULL;

    ttMove = Root ? Rml[0].pv[0] : tte ? tte->move() : MOVE_NONE;

    // At PV nodes we check for exact scores, while at non-PV nodes we check for
    // a fail high/low. Biggest advantage at probing at PV nodes is to have a
    // smooth experience in analysis mode.
    if (   !Root
            &&  tte
            &&  tte->value() != VALUE_NONE
            && &#40;PvNode ? tte->depth&#40;) >= depth && tte->type&#40;) == VALUE_TYPE_EXACT && tte->value&#40;) > alpha && tte->value&#40;) < beta
                &#58; ok_to_use_TT&#40;tte, depth, beta, ss->ply&#41;) )
    &#123;
        TT.store&#40;posKey, tte->value&#40;), tte->type&#40;), tte->depth&#40;), tte->move&#40;), tte->static_value&#40;), tte->static_value_margin&#40;));
        ss->currentMove = ttMove; // Can be MOVE_NONE
        if &#40;tte->value&#40;) >= VALUE_MATE_IN_PLY_MAX&#41;
            ss->mateKiller = ttMove;
        if (    tte->value&#40;) >= beta
                &&  ttMove
                && !pos.move_is_capture_or_promotion&#40;ttMove&#41;
                &&  ttMove != ss->killers&#91;0&#93;)
        &#123;
            ss->killers&#91;1&#93; = ss->killers&#91;0&#93;;
            ss->killers&#91;0&#93; = ttMove;
        &#125;
        return value_from_tt&#40;tte->value&#40;), ss->ply&#41;;
    &#125;

cdani wrote:As I think many people will not see it as is buried in a long thread, I publish here this again.

I added to Stockfish the capability of saving the full hash to file, to allow the user to recover a previous analysis session and continue it. It has the same added uci options than in Andscacs.
The saved hash file will be of the same size of the hash memory, so if you defined 4 GB of hash, such will be the file size. Saving and loading such big files can take some time.

Source and executable:
www.andscacs.com/downloads/stockfish_x6 ... vehash.zip

To be able to do it I have added 4 new uci parameters:

option name NeverClearHash type check default false
option name HashFile type string default hash.hsh
option name SaveHashtoFile type button
option name LoadHashfromFile type button

You can set the NeverClearHash option to avoid that the hash could be cleared by a Clear Hash or ucinewgame command.
The HashFile parameter is the full file name with path information. If you don't set the path, it will be saved in the current folder. It defaults to hash.hsh.
To save the hash, stop the analysis and press the SaveHashtoFile button in the uci options screen of the GUI.
To load the hash file, load the game you are interested in, load the engine withouth starting it, and press the LoadHashfromFile button in the uci options screen of the GUI. Now you can start the analysis.

I have not tested it much. Anything just tell me.

The modified code is between
//dani170724
and
//enddani170724

duncan wrote: is there a reason why LoadHashfromFile has to be clicked for it to work, as opposed to loading by default from current directory. ?as there is a danger if you forget to click LoadHashfromFile and then save it. you can overwrite days of analysis.