X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=d47fab1fea3564f3c944717b9c26295f2d9653bb;hp=791cbc6fb580901a567296d23a0eeed08f892969;hb=876ceb1feb466f4dd2e29d01433878b8cf29cd6f;hpb=b366c7dc38145278a00c51a560a4f7b6e03a0b2a diff --git a/src/search.cpp b/src/search.cpp index 791cbc6f..d47fab1f 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -129,7 +129,7 @@ namespace { void extract_pv_from_tt(Position& pos); void insert_pv_in_tt(Position& pos); - std::string pv_info_to_uci(Position& pos, Depth depth, Value alpha, Value beta, int pvLine = 0); + std::string pv_info_to_uci(Position& pos, int depth, Value alpha, Value beta, int pvLine = 0); int64_t nodes; Value pv_score; @@ -297,7 +297,6 @@ namespace { Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply); - bool ok_to_use_TT_PV(const TTEntry* tte, Depth depth, Value alpha, Value beta, int ply); bool connected_threat(const Position& pos, Move m, Move threat); Value refine_eval(const TTEntry* tte, Value defaultEval, int ply); void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount); @@ -606,9 +605,8 @@ namespace { SearchStack ss[PLY_MAX_PLUS_2]; Value bestValues[PLY_MAX_PLUS_2]; int bestMoveChanges[PLY_MAX_PLUS_2]; - int iteration, researchCountFL, researchCountFH, aspirationDelta; + int depth, researchCountFL, researchCountFH, aspirationDelta; Value value, alpha, beta; - Depth depth; Move bestMove, easyMove; // Moves to search are verified, scored and sorted @@ -618,51 +616,43 @@ namespace { TT.new_search(); H.clear(); memset(ss, 0, PLY_MAX_PLUS_2 * sizeof(SearchStack)); - alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; *ponderMove = bestMove = easyMove = MOVE_NONE; - aspirationDelta = 0; - iteration = 1; + depth = aspirationDelta = 0; ss->currentMove = MOVE_NULL; // Hack to skip update_gains() + alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; // Handle special case of searching on a mate/stale position if (Rml.size() == 0) { - cout << "info depth " << iteration << " score " + cout << "info depth 0 score " << value_to_uci(pos.is_check() ? -VALUE_MATE : VALUE_DRAW) << endl; return MOVE_NONE; } - // Send initial scoring (iteration 1) - cout << set960(pos.is_chess960()) // Is enough to set once at the beginning - << "info depth " << iteration - << "\n" << Rml[0].pv_info_to_uci(pos, ONE_PLY, alpha, beta) << endl; - // Is one move significantly better than others after initial scoring ? if ( Rml.size() == 1 || Rml[0].pv_score > Rml[1].pv_score + EasyMoveMargin) easyMove = Rml[0].pv[0]; // Iterative deepening loop - while (++iteration <= PLY_MAX && (!MaxDepth || iteration <= MaxDepth) && !StopRequest) + while (++depth <= PLY_MAX && (!MaxDepth || depth <= MaxDepth) && !StopRequest) { - cout << "info depth " << iteration << endl; - Rml.bestMoveChanges = researchCountFL = researchCountFH = 0; - depth = (iteration - 1) * ONE_PLY; + cout << "info depth " << depth << endl; // Calculate dynamic aspiration window based on previous iterations - if (MultiPV == 1 && iteration >= 6 && abs(bestValues[iteration - 1]) < VALUE_KNOWN_WIN) + if (MultiPV == 1 && depth >= 5 && abs(bestValues[depth - 1]) < VALUE_KNOWN_WIN) { - int prevDelta1 = bestValues[iteration - 1] - bestValues[iteration - 2]; - int prevDelta2 = bestValues[iteration - 2] - bestValues[iteration - 3]; + int prevDelta1 = bestValues[depth - 1] - bestValues[depth - 2]; + int prevDelta2 = bestValues[depth - 2] - bestValues[depth - 3]; - aspirationDelta = Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16); + aspirationDelta = Min(Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24); aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize - alpha = Max(bestValues[iteration - 1] - aspirationDelta, -VALUE_INFINITE); - beta = Min(bestValues[iteration - 1] + aspirationDelta, VALUE_INFINITE); + alpha = Max(bestValues[depth - 1] - aspirationDelta, -VALUE_INFINITE); + beta = Min(bestValues[depth - 1] + aspirationDelta, VALUE_INFINITE); } // Start with a small aspiration window and, in case of fail high/low, @@ -670,12 +660,16 @@ namespace { while (true) { // Search starting from ss+1 to allow calling update_gains() - value = search(pos, ss+1, alpha, beta, depth, 0); + value = search(pos, ss+1, alpha, beta, depth * ONE_PLY, 0); - // Write PV lines to transposition table, in case the relevant entries - // have been overwritten during the search. + // Send PV line to GUI and write to transposition table in case the + // relevant entries have been overwritten during the search. for (int i = 0; i < Min(MultiPV, (int)Rml.size()); i++) + { Rml[i].insert_pv_in_tt(pos); + cout << set960(pos.is_chess960()) + << Rml[i].pv_info_to_uci(pos, depth, alpha, beta, i) << endl; + } // Value cannot be trusted. Break out immediately! if (StopRequest) @@ -704,8 +698,8 @@ namespace { // Collect info about search result bestMove = Rml[0].pv[0]; - bestValues[iteration] = value; - bestMoveChanges[iteration] = Rml.bestMoveChanges; + bestValues[depth] = value; + bestMoveChanges[depth] = Rml.bestMoveChanges; // Drop the easy move if differs from the new best move if (bestMove != easyMove) @@ -717,15 +711,15 @@ namespace { bool noMoreTime = false; // Stop search early when the last two iterations returned a mate score - if ( iteration >= 6 - && abs(bestValues[iteration]) >= abs(VALUE_MATE) - 100 - && abs(bestValues[iteration-1]) >= abs(VALUE_MATE) - 100) + if ( depth >= 5 + && abs(bestValues[depth]) >= abs(VALUE_MATE) - 100 + && abs(bestValues[depth - 1]) >= abs(VALUE_MATE) - 100) noMoreTime = true; // Stop search early if one move seems to be much better than the // others or if there is only a single legal move. In this latter // case we search up to Iteration 8 anyway to get a proper score. - if ( iteration >= 8 + if ( depth >= 7 && easyMove == bestMove && ( Rml.size() == 1 ||( Rml[0].nodes > (pos.nodes_searched() * 85) / 100 @@ -735,8 +729,8 @@ namespace { noMoreTime = true; // Add some extra time if the best move has changed during the last two iterations - if (iteration > 5 && iteration <= 50) - TimeMgr.pv_instability(bestMoveChanges[iteration], bestMoveChanges[iteration-1]); + if (depth > 4 && depth < 50) + TimeMgr.pv_instability(bestMoveChanges[depth], bestMoveChanges[depth-1]); // Stop search if most of MaxSearchTime is consumed at the end of the // iteration. We probably don't have enough time to search the first @@ -839,10 +833,13 @@ namespace { tte = TT.retrieve(posKey); ttMove = tte ? tte->move() : MOVE_NONE; - // At PV nodes we check for exact scores within (alha, beta) range, while - // at non-PV nodes we check for and return a fail high/low. Biggest advantage - // at probing at PV nodes is to have a smooth experience in analysis mode. - if (!Root && tte && (PvNode ? ok_to_use_TT_PV(tte, depth, alpha, beta, ply) : ok_to_use_TT(tte, depth, beta, ply))) + // At PV nodes we check for exact scores, while at non-PV nodes we check for + // and return a fail high/low. Biggest advantage at probing at PV nodes is + // to have a smooth experience in analysis mode. + if ( !Root + && tte + && (PvNode ? tte->depth() >= depth && tte->type() == VALUE_TYPE_EXACT + : ok_to_use_TT(tte, depth, beta, ply))) { TT.refresh(tte); ss->bestMove = ttMove; // Can be MOVE_NONE @@ -1261,13 +1258,8 @@ split_point_start: // At split points actual search starts from here if (!isPvMove && MultiPV == 1) Rml.bestMoveChanges++; - // Inform GUI that PV has changed, in case of multi-pv UCI protocol - // requires we send all the PV lines properly sorted. Rml.sort_multipv(moveCount); - for (int j = 0; j < Min(MultiPV, (int)Rml.size()); j++) - cout << Rml[j].pv_info_to_uci(pos, depth, alpha, beta, j) << endl; - // Update alpha. In multi-pv we don't use aspiration window, so // set alpha equal to minimum score among the PV lines. if (MultiPV > 1) @@ -1794,9 +1786,7 @@ split_point_start: // At split points actual search starts from here // ok_to_use_TT() returns true if a transposition table score - // can be used at a given point in search. There are two versions - // one to be used in non-PV nodes and one in PV nodes where we look - // for an exact score that falls between (alha, beta) boundaries. + // can be used at a given point in search. bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply) { @@ -1810,17 +1800,6 @@ split_point_start: // At split points actual search starts from here || ((tte->type() & VALUE_TYPE_UPPER) && v < beta)); } - bool ok_to_use_TT_PV(const TTEntry* tte, Depth depth, Value alpha, Value beta, int ply) { - - Value v = value_from_tt(tte->value(), ply); - - return tte->depth() >= depth - && tte->type() == VALUE_TYPE_EXACT - && tte->move() != MOVE_NONE - && v < beta - && v > alpha; - } - // refine_eval() returns the transposition table score if // possible otherwise falls back on static position evaluation. @@ -2552,7 +2531,7 @@ split_point_start: // At split points actual search starts from here // formatted according to UCI specification and eventually writes the info // to a log file. It is called at each iteration or after a new pv is found. - std::string RootMove::pv_info_to_uci(Position& pos, Depth depth, Value alpha, Value beta, int pvLine) { + std::string RootMove::pv_info_to_uci(Position& pos, int depth, Value alpha, Value beta, int pvLine) { std::stringstream s, l; Move* m = pv; @@ -2560,7 +2539,7 @@ split_point_start: // At split points actual search starts from here while (*m != MOVE_NONE) l << *m++ << " "; - s << "info depth " << depth / ONE_PLY + s << "info depth " << depth << " seldepth " << int(m - pv) << " multipv " << pvLine + 1 << " score " << value_to_uci(pv_score) @@ -2575,7 +2554,7 @@ split_point_start: // At split points actual search starts from here ValueType t = pv_score >= beta ? VALUE_TYPE_LOWER : pv_score <= alpha ? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT; - LogFile << pretty_pv(pos, current_search_time(), depth / ONE_PLY, pv_score, t, pv) << endl; + LogFile << pretty_pv(pos, current_search_time(), depth, pv_score, t, pv) << endl; } return s.str(); }