X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=63c9e076f61ce6a713a162bace28dfde429b9fa9;hp=c85cdb5d689fcc1ee47f336812a1d9d310595ec0;hb=c2cefa6de0807e389709a1a12591eb3a86017d08;hpb=5d90c149b5804403e5e8c1a25d0b37577b059712 diff --git a/src/search.cpp b/src/search.cpp index c85cdb5d..63c9e076 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -99,7 +99,6 @@ namespace { void id_loop(Position& pos); Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); - bool check_is_dangerous(const Position& pos, Move move, Value futilityBase, Value beta); bool allows(const Position& pos, Move first, Move second); bool refutes(const Position& pos, Move first, Move second); string uci_pv(const Position& pos, int depth, Value alpha, Value beta); @@ -153,8 +152,8 @@ void Search::init() { // Init futility move count array for (d = 0; d < 32; d++) { - FutilityMoveCounts[0][d] = int(3.001 + 0.3 * pow(double(d ), 1.8)) * (d < 5 ? 4 : 3) / 4; - FutilityMoveCounts[1][d] = int(3.001 + 0.3 * pow(double(d + 0.98), 1.8)); + FutilityMoveCounts[0][d] = int(3 + 0.3 * pow(double(d ), 1.8)) * 3/4 + (2 < d && d < 5); + FutilityMoveCounts[1][d] = int(3 + 0.3 * pow(double(d + 0.98), 1.8)); } } @@ -237,7 +236,7 @@ void Search::think() { } // Reset the threads, still sleeping: will be wake up at split time - for (size_t i = 0; i < Threads.size(); i++) + for (size_t i = 0; i < Threads.size(); ++i) Threads[i]->maxPly = 0; Threads.sleepWhileIdle = Options["Idle Threads Sleep"]; @@ -334,11 +333,11 @@ namespace { while (++depth <= MAX_PLY && !Signals.stop && (!Limits.depth || depth <= Limits.depth)) { // Age out PV variability metric - BestMoveChanges *= 0.8; + BestMoveChanges *= 0.8f; // Save last iteration's scores before first PV line is searched and all // the move scores but the (new) PV are set to -VALUE_INFINITE. - for (size_t i = 0; i < RootMoves.size(); i++) + for (size_t i = 0; i < RootMoves.size(); ++i) RootMoves[i].prevScore = RootMoves[i].score; // MultiPV loop. We perform a full root search for each PV line @@ -368,7 +367,7 @@ namespace { // Write PV back to transposition table in case the relevant // entries have been overwritten during the search. - for (size_t i = 0; i <= PVIdx; i++) + for (size_t i = 0; i <= PVIdx; ++i) RootMoves[i].insert_pv_in_tt(pos); // If search has been stopped return immediately. Sorting and @@ -781,7 +780,7 @@ moves_loop: // When in check and at SpNode search starts from here singularExtensionNode = !RootNode && !SpNode - && depth >= (PvNode ? 6 * ONE_PLY : 8 * ONE_PLY) + && depth >= 8 * ONE_PLY && ttMove != MOVE_NONE && !excludedMove // Recursive singular search is not allowed && (tte->bound() & BOUND_LOWER) @@ -836,7 +835,7 @@ moves_loop: // When in check and at SpNode search starts from here ext = ONE_PLY; else if (givesCheck && pos.see_sign(move) >= 0) - ext = ONE_PLY / 2; + ext = inCheck || ss->staticEval <= alpha ? ONE_PLY : ONE_PLY / 2; // Singular extension search. If all moves but one fail low on a search of // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move @@ -938,7 +937,7 @@ moves_loop: // When in check and at SpNode search starts from here // Step 15. Reduced depth search (LMR). If the move fails high will be // re-searched at full depth. - if ( depth > 3 * ONE_PLY + if ( depth >= 3 * ONE_PLY && !pvMove && !captureOrPromotion && move != ttMove @@ -950,8 +949,11 @@ moves_loop: // When in check and at SpNode search starts from here if (!PvNode && cutNode) ss->reduction += ONE_PLY; + else if (History[pos.piece_on(to_sq(move))][to_sq(move)] < 0) + ss->reduction += ONE_PLY / 2; + if (move == countermoves[0] || move == countermoves[1]) - ss->reduction = std::max(DEPTH_ZERO, ss->reduction-ONE_PLY); + ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY); Depth d = std::max(newDepth - ss->reduction, ONE_PLY); if (SpNode) @@ -1103,7 +1105,7 @@ moves_loop: // When in check and at SpNode search starts from here // played non-capture moves. Value bonus = Value(int(depth) * int(depth)); History.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus); - for (int i = 0; i < quietCount - 1; i++) + for (int i = 0; i < quietCount - 1; ++i) { Move m = quietsSearched[i]; History.update(pos.piece_moved(m), to_sq(m), -bonus); @@ -1267,16 +1269,6 @@ moves_loop: // When in check and at SpNode search starts from here && pos.see_sign(move) < 0) continue; - // Don't search useless checks - if ( !PvNode - && !InCheck - && givesCheck - && move != ttMove - && !pos.is_capture_or_promotion(move) - && ss->staticEval + PawnValueMg / 4 < beta - && !check_is_dangerous(pos, move, futilityBase, beta)) - continue; - // Check for legality only before to do the move if (!pos.pl_move_is_legal(move, ci.pinned)) continue; @@ -1354,42 +1346,6 @@ moves_loop: // When in check and at SpNode search starts from here } - // check_is_dangerous() tests if a checking move can be pruned in qsearch() - - bool check_is_dangerous(const Position& pos, Move move, Value futilityBase, Value beta) - { - Piece pc = pos.piece_moved(move); - Square from = from_sq(move); - Square to = to_sq(move); - Color them = ~pos.side_to_move(); - Square ksq = pos.king_square(them); - Bitboard enemies = pos.pieces(them); - Bitboard kingAtt = pos.attacks_from(ksq); - Bitboard occ = pos.pieces() ^ from ^ ksq; - Bitboard oldAtt = pos.attacks_from(pc, from, occ); - Bitboard newAtt = pos.attacks_from(pc, to, occ); - - // Checks which give opponent's king at most one escape square are dangerous - if (!more_than_one(kingAtt & ~(enemies | newAtt | to))) - return true; - - // Queen contact check is very dangerous - if (type_of(pc) == QUEEN && (kingAtt & to)) - return true; - - // Creating new double threats with checks is dangerous - Bitboard b = (enemies ^ ksq) & newAtt & ~oldAtt; - while (b) - { - // Note that here we generate illegal "double move"! - if (futilityBase + PieceValue[EG][pos.piece_on(pop_lsb(&b))] >= beta) - return true; - } - - return false; - } - - // allows() tests whether the 'first' move at previous ply somehow makes the // 'second' move possible, for instance if the moving piece is the same in // both moves. Normally the second move is the threat (the best move returned @@ -1400,7 +1356,7 @@ moves_loop: // When in check and at SpNode search starts from here assert(is_ok(first)); assert(is_ok(second)); assert(color_of(pos.piece_on(from_sq(second))) == ~pos.side_to_move()); - assert(color_of(pos.piece_on(to_sq(first))) == ~pos.side_to_move()); + assert(type_of(first) == CASTLE || color_of(pos.piece_on(to_sq(first))) == ~pos.side_to_move()); Square m1from = from_sq(first); Square m2from = from_sq(second); @@ -1408,7 +1364,10 @@ moves_loop: // When in check and at SpNode search starts from here Square m2to = to_sq(second); // The piece is the same or second's destination was vacated by the first move - if (m1to == m2from || m2to == m1from) + // We exclude the trivial case where a sliding piece does in two moves what + // it could do in one move: eg. Ra1a2, Ra2a3. + if ( m2to == m1from + || (m1to == m2from && !squares_aligned(m1from, m2from, m2to))) return true; // Second one moves through the square vacated by first one @@ -1500,7 +1459,7 @@ moves_loop: // When in check and at SpNode search starts from here // Choose best move. For each move score we add two terms both dependent on // weakness, one deterministic and bigger for weaker moves, and one random, // then we choose the move with the resulting highest score. - for (size_t i = 0; i < PVSize; i++) + for (size_t i = 0; i < PVSize; ++i) { int s = RootMoves[i].score; @@ -1533,11 +1492,11 @@ moves_loop: // When in check and at SpNode search starts from here size_t uciPVSize = std::min((size_t)Options["MultiPV"], RootMoves.size()); int selDepth = 0; - for (size_t i = 0; i < Threads.size(); i++) + for (size_t i = 0; i < Threads.size(); ++i) if (Threads[i]->maxPly > selDepth) selDepth = Threads[i]->maxPly; - for (size_t i = 0; i < uciPVSize; i++) + for (size_t i = 0; i < uciPVSize; ++i) { bool updated = (i <= PVIdx); @@ -1774,7 +1733,7 @@ void check_time() { // Loop across all split points and sum accumulated SplitPoint nodes plus // all the currently active positions nodes. - for (size_t i = 0; i < Threads.size(); i++) + for (size_t i = 0; i < Threads.size(); ++i) for (int j = 0; j < Threads[i]->splitPointsSize; j++) { SplitPoint& sp = Threads[i]->splitPoints[j];