X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=fc5dc4ee8ab305759e255a7d86ed110795decbf2;hp=4cce6a9171de9139d8e51e717d966af819912492;hb=4cc272cb94d0f226fc6af96076e104dfbdf3c4c4;hpb=e5ffe9959c40a5ec6c4bca83a5a48070cae7fa5b diff --git a/src/search.cpp b/src/search.cpp index 4cce6a91..fc5dc4ee 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -20,11 +20,11 @@ #include #include #include -#include #include #include #include #include +#include #include "book.h" #include "evaluate.h" @@ -129,7 +129,7 @@ namespace { inline Value futility_margin(Depth d, int mn) { - return d < 7 * ONE_PLY ? FutilityMargins[Max(d, 1)][Min(mn, 63)] + return d < 7 * ONE_PLY ? FutilityMargins[std::max(int(d), 1)][std::min(mn, 63)] : 2 * VALUE_INFINITE; } @@ -145,7 +145,7 @@ namespace { template inline Depth reduction(Depth d, int mn) { - return (Depth) Reductions[PvNode][Min(d / ONE_PLY, 63)][Min(mn, 63)]; + return (Depth) Reductions[PvNode][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)]; } // Easy move margin. An easy move candidate must be at least this much @@ -159,25 +159,17 @@ namespace { RootMoveList Rml; // MultiPV mode - int MultiPV, UCIMultiPV, MultiPVIteration; + int MultiPV, UCIMultiPV, MultiPVIdx; // Time management variables bool StopOnPonderhit, FirstRootMove, StopRequest, QuitRequest, AspirationFailLow; TimeManager TimeMgr; SearchLimits Limits; - // Log file - std::ofstream LogFile; - // Skill level adjustment int SkillLevel; bool SkillLevelEnabled; - // Node counters, used only by thread[0] but try to keep in different cache - // lines (64 bytes each) from the heavy multi-thread read accessed variables. - int NodesSincePoll; - int NodesBetweenPolls = 30000; - // History table History H; @@ -200,16 +192,14 @@ namespace { 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); - void update_gains(const Position& pos, Move move, Value before, Value after); void do_skill_level(Move* best, Move* ponder); - int current_search_time(int set = 0); + int elapsed_search_time(int set = 0); string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE); string speed_to_uci(int64_t nodes); string pv_to_uci(const Move pv[], int pvNum, bool chess960); string pretty_pv(Position& pos, int depth, Value score, int time, Move pv[]); string depth_to_uci(Depth depth); - void poll(const Position& pos); void wait_for_stop_or_ponderhit(); // MovePickerExt template class extends MovePicker and allows to choose at compile @@ -270,7 +260,7 @@ namespace { if (moveIsCheck && pos.see_sign(m) >= 0) result += CheckExtension[PvNode]; - if (piece_type(pos.piece_on(move_from(m))) == PAWN) + if (type_of(pos.piece_on(move_from(m))) == PAWN) { Color c = pos.side_to_move(); if (relative_rank(c, move_to(m)) == RANK_7) @@ -286,16 +276,16 @@ namespace { } if ( captureOrPromotion - && piece_type(pos.piece_on(move_to(m))) != PAWN + && type_of(pos.piece_on(move_to(m))) != PAWN && ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) - - piece_value_midgame(pos.piece_on(move_to(m))) == VALUE_ZERO) - && !move_is_special(m)) + - PieceValueMidgame[pos.piece_on(move_to(m))] == VALUE_ZERO) + && !is_special(m)) { result += PawnEndgameExtension[PvNode]; *dangerous = true; } - return Min(result, ONE_PLY); + return std::min(result, ONE_PLY); } } // namespace @@ -363,35 +353,25 @@ int64_t perft(Position& pos, Depth depth) { bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { - static Book book; + static Book book; // Defined static to initialize the PRNG only once + + // Save "search start" time and reset elapsed time to zero + elapsed_search_time(get_system_time()); // Initialize global search-related variables StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = false; - NodesSincePoll = 0; - current_search_time(get_system_time()); Limits = limits; - TimeMgr.init(Limits, pos.startpos_ply_counter()); - // Set output steram in normal or chess960 mode + // Set output stream mode: normal or chess960. Castling notation is different cout << set960(pos.is_chess960()); - // Set best NodesBetweenPolls interval to avoid lagging under time pressure - if (Limits.maxNodes) - NodesBetweenPolls = Min(Limits.maxNodes, 30000); - else if (Limits.time && Limits.time < 1000) - NodesBetweenPolls = 1000; - else if (Limits.time && Limits.time < 5000) - NodesBetweenPolls = 5000; - else - NodesBetweenPolls = 30000; - // Look for a book move if (Options["OwnBook"].value()) { if (Options["Book File"].value() != book.name()) book.open(Options["Book File"].value()); - Move bookMove = book.get_move(pos, Options["Best Book Move"].value()); + Move bookMove = book.probe(pos, Options["Best Book Move"].value()); if (bookMove != MOVE_NONE) { if (Limits.ponder) @@ -402,10 +382,7 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { } } - // Read UCI options - UCIMultiPV = Options["MultiPV"].value(); - SkillLevel = Options["Skill Level"].value(); - + // Read UCI options: GUI could change UCI parameters during the game read_evaluation_uci_options(pos.side_to_move()); Threads.read_uci_options(); @@ -418,60 +395,79 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { TT.clear(); } + UCIMultiPV = Options["MultiPV"].value(); + SkillLevel = Options["Skill Level"].value(); + // Do we have to play with skill handicap? In this case enable MultiPV that // we will use behind the scenes to retrieve a set of possible moves. SkillLevelEnabled = (SkillLevel < 20); - MultiPV = (SkillLevelEnabled ? Max(UCIMultiPV, 4) : UCIMultiPV); + MultiPV = (SkillLevelEnabled ? std::max(UCIMultiPV, 4) : UCIMultiPV); + + // Write current search header to log file + if (Options["Use Search Log"].value()) + { + Log log(Options["Search Log Filename"].value()); + log << "\nSearching: " << pos.to_fen() + << "\ninfinite: " << Limits.infinite + << " ponder: " << Limits.ponder + << " time: " << Limits.time + << " increment: " << Limits.increment + << " moves to go: " << Limits.movesToGo + << endl; + } // Wake up needed threads and reset maxPly counter for (int i = 0; i < Threads.size(); i++) { - Threads[i].wake_up(); Threads[i].maxPly = 0; + Threads[i].wake_up(); } - // Write to log file and keep it open to be accessed during the search - if (Options["Use Search Log"].value()) - { - string name = Options["Search Log Filename"].value(); - LogFile.open(name.c_str(), std::ios::out | std::ios::app); - - if (LogFile.is_open()) - LogFile << "\nSearching: " << pos.to_fen() - << "\ninfinite: " << Limits.infinite - << " ponder: " << Limits.ponder - << " time: " << Limits.time - << " increment: " << Limits.increment - << " moves to go: " << Limits.movesToGo - << endl; - } + // Set best timer interval to avoid lagging under time pressure. Timer is + // used to check for remaining available thinking time. + TimeMgr.init(Limits, pos.startpos_ply_counter()); + + if (TimeMgr.available_time()) + Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 8, 20))); + else + Threads.set_timer(100); + + // Start async mode to catch UCI commands sent to us while searching, + // like "quit", "stop", etc. + Threads.start_listener(); // We're ready to start thinking. Call the iterative deepening loop function Move ponderMove = MOVE_NONE; Move bestMove = id_loop(pos, searchMoves, &ponderMove); - // Write final search statistics and close log file - if (LogFile.is_open()) + // From now on any UCI command will be read in-sync with Threads.getline() + Threads.stop_listener(); + + // Stop timer, no need to check for available time any more + Threads.set_timer(0); + + // This makes all the slave threads to go to sleep, if not already sleeping + Threads.set_size(1); + + // Write current search final statistics to log file + if (Options["Use Search Log"].value()) { - int t = current_search_time(); + int e = elapsed_search_time(); - LogFile << "Nodes: " << pos.nodes_searched() - << "\nNodes/second: " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0) - << "\nBest move: " << move_to_san(pos, bestMove); + Log log(Options["Search Log Filename"].value()); + log << "Nodes: " << pos.nodes_searched() + << "\nNodes/second: " << (e > 0 ? pos.nodes_searched() * 1000 / e : 0) + << "\nBest move: " << move_to_san(pos, bestMove); StateInfo st; pos.do_move(bestMove, st); - LogFile << "\nPonder move: " << move_to_san(pos, ponderMove) << endl; + log << "\nPonder move: " << move_to_san(pos, ponderMove) << endl; pos.undo_move(bestMove); // Return from think() with unchanged position - LogFile.close(); } - // This makes all the threads to go to sleep - Threads.set_size(1); - - // If we are pondering or in infinite search, we shouldn't print the - // best move before we are told to do so. - if (!StopRequest && (Limits.ponder || Limits.infinite)) + // If we are pondering or in infinite search, we shouldn't print the best move + // before we are told to do so. + if (Limits.ponder || Limits.infinite) wait_for_stop_or_ponderhit(); // Could be MOVE_NONE when searching on a stalemate position @@ -500,7 +496,7 @@ namespace { Value bestValues[PLY_MAX_PLUS_2]; int bestMoveChanges[PLY_MAX_PLUS_2]; int depth, aspirationDelta; - Value value, alpha, beta; + Value bestValue, alpha, beta; Move bestMove, easyMove, skillBest, skillPonder; // Initialize stuff before a new search @@ -509,8 +505,8 @@ namespace { H.clear(); *ponderMove = bestMove = easyMove = skillBest = skillPonder = MOVE_NONE; depth = aspirationDelta = 0; - value = alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; - ss->currentMove = MOVE_NULL; // Hack to skip update_gains() + bestValue = alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; + ss->currentMove = MOVE_NULL; // Hack to skip update gains // Moves to search are verified and copied Rml.init(pos, searchMoves); @@ -527,27 +523,26 @@ namespace { // Iterative deepening loop until requested to stop or target depth reached while (!StopRequest && ++depth <= PLY_MAX && (!Limits.maxDepth || depth <= Limits.maxDepth)) { - // Save last iteration's scores, this needs to be done now, because in - // the following MultiPV loop Rml moves could be reordered. + // Save now last iteration's scores, before Rml moves are reordered for (size_t i = 0; i < Rml.size(); i++) Rml[i].prevScore = Rml[i].score; Rml.bestMoveChanges = 0; - // MultiPV iteration loop - for (MultiPVIteration = 0; MultiPVIteration < Min(MultiPV, (int)Rml.size()); MultiPVIteration++) + // MultiPV loop. We perform a full root search for each PV line + for (MultiPVIdx = 0; MultiPVIdx < std::min(MultiPV, (int)Rml.size()); MultiPVIdx++) { // Calculate dynamic aspiration window based on previous iterations - if (depth >= 5 && abs(Rml[MultiPVIteration].prevScore) < VALUE_KNOWN_WIN) + if (depth >= 5 && abs(Rml[MultiPVIdx].prevScore) < VALUE_KNOWN_WIN) { int prevDelta1 = bestValues[depth - 1] - bestValues[depth - 2]; int prevDelta2 = bestValues[depth - 2] - bestValues[depth - 3]; - aspirationDelta = Min(Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24); + aspirationDelta = std::min(std::max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24); aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize - alpha = Max(Rml[MultiPVIteration].prevScore - aspirationDelta, -VALUE_INFINITE); - beta = Min(Rml[MultiPVIteration].prevScore + aspirationDelta, VALUE_INFINITE); + alpha = std::max(Rml[MultiPVIdx].prevScore - aspirationDelta, -VALUE_INFINITE); + beta = std::min(Rml[MultiPVIdx].prevScore + aspirationDelta, VALUE_INFINITE); } else { @@ -558,78 +553,97 @@ namespace { // Start with a small aspiration window and, in case of fail high/low, // research with bigger window until not failing high/low anymore. do { - // Search starting from ss+1 to allow referencing (ss-1). This is - // needed by update_gains() and ss copy when splitting at Root. - value = search(pos, ss+1, alpha, beta, depth * ONE_PLY); - - // It is critical that sorting is done with a stable algorithm - // because all the values but the first are usually set to - // -VALUE_INFINITE and we want to keep the same order for all - // the moves but the new PV that goes to head. - sort(Rml.begin() + MultiPVIteration, Rml.end()); - - // In case we have found an exact score reorder the PV moves - // before leaving the fail high/low loop, otherwise leave the - // last PV move in its position so to be searched again. - if (value > alpha && value < beta) - sort(Rml.begin(), Rml.begin() + MultiPVIteration); + // Search starts from ss+1 to allow referencing (ss-1). This is + // needed by update gains and ss copy when splitting at Root. + bestValue = search(pos, ss+1, alpha, beta, depth * ONE_PLY); + + // Bring to front the best move. It is critical that sorting is + // done with a stable algorithm because all the values but the first + // and eventually the new best one are set to -VALUE_INFINITE and + // we want to keep the same order for all the moves but the new + // PV that goes to the front. Note that in case of MultiPV search + // the already searched PV lines are preserved. + sort(Rml.begin() + MultiPVIdx, Rml.end()); + + // In case we have found an exact score and we are going to leave + // the fail high/low loop then reorder the PV moves, otherwise + // leave the last PV move in its position so to be searched again. + // Of course this is needed only in MultiPV search. + if (MultiPVIdx && bestValue > alpha && bestValue < beta) + sort(Rml.begin(), Rml.begin() + MultiPVIdx); // Write PV back to transposition table in case the relevant entries // have been overwritten during the search. - for (int i = 0; i <= MultiPVIteration; i++) + for (int i = 0; i <= MultiPVIdx; i++) Rml[i].insert_pv_in_tt(pos); - // Value cannot be trusted. Break out immediately! + // If search has been stopped exit the aspiration window loop, + // note that sorting and writing PV back to TT is safe becuase + // Rml is still valid, although refers to the previous iteration. if (StopRequest) break; // Send full PV info to GUI if we are going to leave the loop or - // if we have a fail high/low and we are deep in the search. - if ((value > alpha && value < beta) || current_search_time() > 2000) - for (int i = 0; i < Min(UCIMultiPV, MultiPVIteration + 1); i++) + // if we have a fail high/low and we are deep in the search. UCI + // protocol requires to send all the PV lines also if are still + // to be searched and so refer to the previous search's score. + if ((bestValue > alpha && bestValue < beta) || elapsed_search_time() > 2000) + for (int i = 0; i < std::min(UCIMultiPV, (int)Rml.size()); i++) + { + bool updated = (i <= MultiPVIdx); + + if (depth == 1 && !updated) + continue; + + Depth d = (updated ? depth : depth - 1) * ONE_PLY; + Value s = (updated ? Rml[i].score : Rml[i].prevScore); + cout << "info" - << depth_to_uci(depth * ONE_PLY) - << (i == MultiPVIteration ? score_to_uci(Rml[i].score, alpha, beta) : - score_to_uci(Rml[i].score)) + << depth_to_uci(d) + << (i == MultiPVIdx ? score_to_uci(s, alpha, beta) : score_to_uci(s)) << speed_to_uci(pos.nodes_searched()) << pv_to_uci(&Rml[i].pv[0], i + 1, pos.is_chess960()) << endl; + } - // In case of failing high/low increase aspiration window and research, - // otherwise exit the fail high/low loop. - if (value >= beta) + // In case of failing high/low increase aspiration window and + // research, otherwise exit the fail high/low loop. + if (bestValue >= beta) { - beta = Min(beta + aspirationDelta, VALUE_INFINITE); + beta = std::min(beta + aspirationDelta, VALUE_INFINITE); aspirationDelta += aspirationDelta / 2; } - else if (value <= alpha) + else if (bestValue <= alpha) { AspirationFailLow = true; StopOnPonderhit = false; - alpha = Max(alpha - aspirationDelta, -VALUE_INFINITE); + alpha = std::max(alpha - aspirationDelta, -VALUE_INFINITE); aspirationDelta += aspirationDelta / 2; } else break; - } while (abs(value) < VALUE_KNOWN_WIN); + } while (abs(bestValue) < VALUE_KNOWN_WIN); } // Collect info about search result bestMove = Rml[0].pv[0]; *ponderMove = Rml[0].pv[1]; - bestValues[depth] = value; + bestValues[depth] = bestValue; bestMoveChanges[depth] = Rml.bestMoveChanges; - // Do we need to pick now the best and the ponder moves ? + // Skills: Do we need to pick now the best and the ponder moves ? if (SkillLevelEnabled && depth == 1 + SkillLevel) do_skill_level(&skillBest, &skillPonder); - if (LogFile.is_open()) - LogFile << pretty_pv(pos, depth, value, current_search_time(), &Rml[0].pv[0]) << endl; + if (Options["Use Search Log"].value()) + { + Log log(Options["Search Log Filename"].value()); + log << pretty_pv(pos, depth, bestValue, elapsed_search_time(), &Rml[0].pv[0]) << endl; + } - // Init easyMove after first iteration or drop if differs from the best move + // Init easyMove at first iteration or drop it if differs from the best move if (depth == 1 && (Rml.size() == 1 || Rml[0].score > Rml[1].score + EasyMoveMargin)) easyMove = bestMove; else if (bestMove != easyMove) @@ -638,16 +652,16 @@ namespace { // Check for some early stop condition if (!StopRequest && Limits.useTimeManagement()) { - // Stop search early if one move seems to be much better than the - // others or if there is only a single legal move. Also in the latter - // case we search up to some depth anyway to get a proper score. + // Easy move: Stop search early if one move seems to be much better + // than the others or if there is only a single legal move. Also in + // the latter case search to some depth anyway to get a proper score. if ( depth >= 7 && easyMove == bestMove && ( Rml.size() == 1 ||( Rml[0].nodes > (pos.nodes_searched() * 85) / 100 - && current_search_time() > TimeMgr.available_time() / 16) + && elapsed_search_time() > TimeMgr.available_time() / 16) ||( Rml[0].nodes > (pos.nodes_searched() * 98) / 100 - && current_search_time() > TimeMgr.available_time() / 32))) + && elapsed_search_time() > TimeMgr.available_time() / 32))) StopRequest = true; // Take in account some extra time if the best move has changed @@ -656,7 +670,7 @@ namespace { // Stop search if most of available time is already consumed. We probably don't // have enough time to search the first move at the next iteration anyway. - if (current_search_time() > (TimeMgr.available_time() * 62) / 100) + if (elapsed_search_time() > (TimeMgr.available_time() * 62) / 100) StopRequest = true; // If we are allowed to ponder do not stop the search now but keep pondering @@ -725,7 +739,7 @@ namespace { if (PvNode && thread.maxPly < ss->ply) thread.maxPly = ss->ply; - // Step 1. Initialize node and poll. Polling can abort search + // Step 1. Initialize node if (!SpNode) { ss->currentMove = ss->bestMove = threatMove = (ss+1)->excludedMove = MOVE_NONE; @@ -741,12 +755,6 @@ namespace { goto split_point_start; } - if (pos.thread() == 0 && ++NodesSincePoll > NodesBetweenPolls) - { - NodesSincePoll = 0; - poll(pos); - } - // Step 2. Check for aborted search and immediate draw if (( StopRequest || pos.is_draw() @@ -756,8 +764,8 @@ namespace { // Step 3. Mate distance pruning if (!RootNode) { - alpha = Max(value_mated_in(ss->ply), alpha); - beta = Min(value_mate_in(ss->ply+1), beta); + alpha = std::max(value_mated_in(ss->ply), alpha); + beta = std::min(value_mate_in(ss->ply+1), beta); if (alpha >= beta) return alpha; } @@ -768,7 +776,7 @@ namespace { excludedMove = ss->excludedMove; posKey = excludedMove ? pos.get_exclusion_key() : pos.get_key(); tte = TT.probe(posKey); - ttMove = RootNode ? Rml[MultiPVIteration].pv[0] : tte ? tte->move() : MOVE_NONE; + ttMove = RootNode ? Rml[MultiPVIdx].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 @@ -778,8 +786,18 @@ namespace { : can_return_tt(tte, depth, beta, ss->ply))) { TT.refresh(tte); - ss->bestMove = ttMove; // Can be MOVE_NONE - return value_from_tt(tte->value(), ss->ply); + ss->bestMove = move = ttMove; // Can be MOVE_NONE + value = value_from_tt(tte->value(), ss->ply); + + if ( value >= beta + && move + && !pos.is_capture_or_promotion(move) + && move != ss->killers[0]) + { + ss->killers[1] = ss->killers[0]; + ss->killers[0] = move; + } + return value; } // Step 5. Evaluate the position statically and update parent's gain statistics @@ -799,8 +817,17 @@ namespace { TT.store(posKey, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, MOVE_NONE, ss->eval, ss->evalMargin); } - // Save gain for the parent non-capture move - update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval); + // Update gain for the parent non-capture move given the static position + // evaluation before and after the move. + if ( (move = (ss-1)->currentMove) != MOVE_NULL + && (ss-1)->eval != VALUE_NONE + && ss->eval != VALUE_NONE + && pos.captured_piece_type() == PIECE_TYPE_NONE + && !is_special(move)) + { + Square to = move_to(move); + H.update_gain(pos.piece_on(to), to, -(ss-1)->eval - ss->eval); + } // Step 6. Razoring (is omitted in PV nodes) if ( !PvNode @@ -849,12 +876,12 @@ namespace { if (refinedValue - PawnValueMidgame > beta) R++; - pos.do_null_move(st); + pos.do_null_move(st); (ss+1)->skipNullMove = true; nullValue = depth-R*ONE_PLY < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) : - search(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY); (ss+1)->skipNullMove = false; - pos.undo_null_move(); + pos.do_null_move(st); if (nullValue >= beta) { @@ -962,15 +989,15 @@ split_point_start: // At split points actual search starts from here && (move = mp.get_next_move()) != MOVE_NONE && !thread.cutoff_occurred()) { - assert(move_is_ok(move)); + assert(is_ok(move)); if (move == excludedMove) continue; - // At root obey the "searchmoves" option and skip moves not listed in Root Move List. - // Also in MultiPV mode we skip moves which already have got an exact score - // in previous MultiPV Iteration. Finally any illegal move is skipped here. - if (RootNode && !Rml.find(move, MultiPVIteration)) + // At root obey the "searchmoves" option and skip moves not listed in Root + // Move List, as a consequence any illegal move is also skipped. In MultiPV + // mode we also skip PV moves which have been already searched. + if (RootNode && !Rml.find(move, MultiPVIdx)) continue; // At PV and SpNode nodes we want all moves to be legal since the beginning @@ -994,16 +1021,16 @@ split_point_start: // At split points actual search starts from here nodes = pos.nodes_searched(); // For long searches send current move info to GUI - if (pos.thread() == 0 && current_search_time() > 2000) + if (pos.thread() == 0 && elapsed_search_time() > 2000) cout << "info" << depth_to_uci(depth) << " currmove " << move - << " currmovenumber " << moveCount + MultiPVIteration << endl; + << " currmovenumber " << moveCount + MultiPVIdx << endl; } // At Root and at first iteration do a PV search on all the moves to score root moves isPvMove = (PvNode && moveCount <= (RootNode && depth <= ONE_PLY ? MAX_MOVES : 1)); givesCheck = pos.move_gives_check(move, ci); - captureOrPromotion = pos.move_is_capture_or_promotion(move); + captureOrPromotion = pos.is_capture_or_promotion(move); // Step 12. Decide the new search depth ext = extension(pos, move, captureOrPromotion, givesCheck, &dangerous); @@ -1043,7 +1070,7 @@ split_point_start: // At split points actual search starts from here && !inCheck && !dangerous && move != ttMove - && !move_is_castle(move)) + && !is_castle(move)) { // Move count based pruning if ( moveCount >= futility_move_count(depth) @@ -1117,7 +1144,7 @@ split_point_start: // At split points actual search starts from here if ( depth > 3 * ONE_PLY && !captureOrPromotion && !dangerous - && !move_is_castle(move) + && !is_castle(move) && ss->killers[0] != move && ss->killers[1] != move && (ss->reduction = reduction(depth, moveCount)) != DEPTH_ZERO) @@ -1223,9 +1250,11 @@ split_point_start: // At split points actual search starts from here } // Step 20. Check for mate and stalemate - // All legal moves have been searched and if there are - // no legal moves, it must be mate or stalemate. - // If one move was excluded return fail low score. + // All legal moves have been searched and if there are no legal moves, it + // must be mate or stalemate. Note that we can have a false positive in + // case of StopRequest or thread.cutoff_occurred() are set, but this is + // harmless because return value is discarded anyhow in the parent nodes. + // If we are in a singular extension search then return a fail low score. if (!SpNode && !moveCount) return excludedMove ? oldAlpha : inCheck ? value_mated_in(ss->ply) : VALUE_DRAW; @@ -1242,7 +1271,7 @@ split_point_start: // At split points actual search starts from here // Update killers and history only for non capture moves that fails high if ( bestValue >= beta - && !pos.move_is_capture_or_promotion(move)) + && !pos.is_capture_or_promotion(move)) { if (move != ss->killers[0]) { @@ -1362,7 +1391,7 @@ split_point_start: // At split points actual search starts from here while ( bestValue < beta && (move = mp.get_next_move()) != MOVE_NONE) { - assert(move_is_ok(move)); + assert(is_ok(move)); givesCheck = pos.move_gives_check(move, ci); @@ -1372,12 +1401,12 @@ split_point_start: // At split points actual search starts from here && !givesCheck && move != ttMove && enoughMaterial - && !move_is_promotion(move) - && !pos.move_is_passed_pawn_push(move)) + && !is_promotion(move) + && !pos.is_passed_pawn_push(move)) { futilityValue = futilityBase - + piece_value_endgame(pos.piece_on(move_to(move))) - + (move_is_ep(move) ? PawnValueEndgame : VALUE_ZERO); + + PieceValueEndgame[pos.piece_on(move_to(move))] + + (is_enpassant(move) ? PawnValueEndgame : VALUE_ZERO); if (futilityValue < beta) { @@ -1398,14 +1427,14 @@ split_point_start: // At split points actual search starts from here evasionPrunable = !PvNode && inCheck && bestValue > VALUE_MATED_IN_PLY_MAX - && !pos.move_is_capture(move) + && !pos.is_capture(move) && !pos.can_castle(pos.side_to_move()); // Don't search moves with negative SEE values if ( !PvNode && (!inCheck || evasionPrunable) && move != ttMove - && !move_is_promotion(move) + && !is_promotion(move) && pos.see_sign(move) < 0) continue; @@ -1414,7 +1443,7 @@ split_point_start: // At split points actual search starts from here && !inCheck && givesCheck && move != ttMove - && !pos.move_is_capture_or_promotion(move) + && !pos.is_capture_or_promotion(move) && ss->eval + PawnValueMidgame / 4 < beta && !check_is_dangerous(pos, move, futilityBase, beta, &bestValue)) { @@ -1483,7 +1512,7 @@ split_point_start: // At split points actual search starts from here from = move_from(move); to = move_to(move); - them = opposite_color(pos.side_to_move()); + them = flip(pos.side_to_move()); ksq = pos.king_square(them); kingAtt = pos.attacks_from(ksq); pc = pos.piece_on(from); @@ -1499,7 +1528,7 @@ split_point_start: // At split points actual search starts from here return true; // Rule 2. Queen contact check is very dangerous - if ( piece_type(pc) == QUEEN + if ( type_of(pc) == QUEEN && bit_is_set(kingAtt, to)) return true; @@ -1509,7 +1538,7 @@ split_point_start: // At split points actual search starts from here while (b) { victimSq = pop_1st_bit(&b); - futilityValue = futilityBase + piece_value_endgame(pos.piece_on(victimSq)); + futilityValue = futilityBase + PieceValueEndgame[pos.piece_on(victimSq)]; // Note that here we generate illegal "double move"! if ( futilityValue >= beta @@ -1538,8 +1567,8 @@ split_point_start: // At split points actual search starts from here Piece p1, p2; Square ksq; - assert(m1 && move_is_ok(m1)); - assert(m2 && move_is_ok(m2)); + assert(is_ok(m1)); + assert(is_ok(m2)); // Case 1: The moving piece is the same in both moves f2 = move_from(m2); @@ -1614,10 +1643,10 @@ split_point_start: // At split points actual search starts from here bool connected_threat(const Position& pos, Move m, Move threat) { - assert(move_is_ok(m)); - assert(threat && move_is_ok(threat)); - assert(!pos.move_is_capture_or_promotion(m)); - assert(!pos.move_is_passed_pawn_push(m)); + assert(is_ok(m)); + assert(is_ok(threat)); + assert(!pos.is_capture_or_promotion(m)); + assert(!pos.is_passed_pawn_push(m)); Square mfrom, mto, tfrom, tto; @@ -1632,9 +1661,9 @@ split_point_start: // At split points actual search starts from here // Case 2: If the threatened piece has value less than or equal to the // value of the threatening piece, don't prune moves which defend it. - if ( pos.move_is_capture(threat) - && ( piece_value_midgame(pos.piece_on(tfrom)) >= piece_value_midgame(pos.piece_on(tto)) - || piece_type(pos.piece_on(tfrom)) == KING) + if ( pos.is_capture(threat) + && ( PieceValueMidgame[pos.piece_on(tfrom)] >= PieceValueMidgame[pos.piece_on(tto)] + || type_of(pos.piece_on(tfrom)) == KING) && pos.move_attacks_square(m, tto)) return true; @@ -1657,8 +1686,8 @@ split_point_start: // At split points actual search starts from here Value v = value_from_tt(tte->value(), ply); return ( tte->depth() >= depth - || v >= Max(VALUE_MATE_IN_PLY_MAX, beta) - || v < Min(VALUE_MATED_IN_PLY_MAX, beta)) + || v >= std::max(VALUE_MATE_IN_PLY_MAX, beta) + || v < std::min(VALUE_MATED_IN_PLY_MAX, beta)) && ( ((tte->type() & VALUE_TYPE_LOWER) && v >= beta) || ((tte->type() & VALUE_TYPE_UPPER) && v < beta)); @@ -1703,24 +1732,10 @@ split_point_start: // At split points actual search starts from here } - // update_gains() updates the gains table of a non-capture move given - // the static position evaluation before and after the move. - - void update_gains(const Position& pos, Move m, Value before, Value after) { - - if ( m != MOVE_NULL - && before != VALUE_NONE - && after != VALUE_NONE - && pos.captured_piece_type() == PIECE_TYPE_NONE - && !move_is_special(m)) - H.update_gain(pos.piece_on(move_to(m)), move_to(m), -(before + after)); - } - - // current_search_time() returns the number of milliseconds which have passed // since the beginning of the current search. - int current_search_time(int set) { + int elapsed_search_time(int set) { static int searchStartTime; @@ -1759,7 +1774,7 @@ split_point_start: // At split points actual search starts from here string speed_to_uci(int64_t nodes) { std::stringstream s; - int t = current_search_time(); + int t = elapsed_search_time(); s << " nodes " << nodes << " nps " << (t > 0 ? int(nodes * 1000 / t) : 0) @@ -1768,6 +1783,7 @@ split_point_start: // At split points actual search starts from here return s.str(); } + // pv_to_uci() returns a string with information on the current PV line // formatted according to UCI specification. @@ -1783,6 +1799,7 @@ split_point_start: // At split points actual search starts from here return s.str(); } + // depth_to_uci() returns a string with information on the current depth and // seldepth formatted according to UCI specification. @@ -1833,6 +1850,7 @@ split_point_start: // At split points actual search starts from here return s.str(); } + // pretty_pv() creates a human-readable string from a position and a PV. // It is used to write search information to the log file (which is created // when the UCI parameter "Use Search Log" is "true"). @@ -1885,104 +1903,30 @@ split_point_start: // At split points actual search starts from here return s.str(); } - // poll() performs two different functions: It polls for user input, and it - // looks at the time consumed so far and decides if it's time to abort the - // search. - - void poll(const Position& pos) { - - static int lastInfoTime; - int t = current_search_time(); - - // Poll for input - if (input_available()) - { - // We are line oriented, don't read single chars - string command; - - if (!std::getline(std::cin, command) || command == "quit") - { - // Quit the program as soon as possible - Limits.ponder = false; - QuitRequest = StopRequest = true; - return; - } - else if (command == "stop") - { - // Stop calculating as soon as possible, but still send the "bestmove" - // and possibly the "ponder" token when finishing the search. - Limits.ponder = false; - StopRequest = true; - } - else if (command == "ponderhit") - { - // The opponent has played the expected move. GUI sends "ponderhit" if - // we were told to ponder on the same move the opponent has played. We - // should continue searching but switching from pondering to normal search. - Limits.ponder = false; - - if (StopOnPonderhit) - StopRequest = true; - } - } - - // Print search information - if (t < 1000) - lastInfoTime = 0; - - else if (lastInfoTime > t) - // HACK: Must be a new search where we searched less than - // NodesBetweenPolls nodes during the first second of search. - lastInfoTime = 0; - - else if (t - lastInfoTime >= 1000) - { - lastInfoTime = t; - - dbg_print_mean(); - dbg_print_hit_rate(); - } - - // Should we stop the search? - if (Limits.ponder) - return; - - bool stillAtFirstMove = FirstRootMove - && !AspirationFailLow - && t > TimeMgr.available_time(); - - bool noMoreTime = t > TimeMgr.maximum_time() - || stillAtFirstMove; - - if ( (Limits.useTimeManagement() && noMoreTime) - || (Limits.maxTime && t >= Limits.maxTime) - || (Limits.maxNodes && pos.nodes_searched() >= Limits.maxNodes)) // FIXME - StopRequest = true; - } - // wait_for_stop_or_ponderhit() is called when the maximum depth is reached // while the program is pondering. The point is to work around a wrinkle in // the UCI protocol: When pondering, the engine is not allowed to give a // "bestmove" before the GUI sends it a "stop" or "ponderhit" command. - // We simply wait here until one of these commands is sent, and return, - // after which the bestmove and pondermove will be printed. + // We simply wait here until one of these commands (that raise StopRequest) is + // sent, and return, after which the bestmove and pondermove will be printed. void wait_for_stop_or_ponderhit() { - string command; - - // Wait for a command from stdin - while ( std::getline(std::cin, command) - && command != "ponderhit" && command != "stop" && command != "quit") {}; + string cmd; + StopOnPonderhit = true; - if (command != "ponderhit" && command != "stop") - QuitRequest = true; // Must be "quit" or getline() returned false + while (!StopRequest) + { + Threads.getline(cmd); + do_uci_async_cmd(cmd); + } } // When playing with strength handicap choose best move among the MultiPV set // using a statistical rule dependent on SkillLevel. Idea by Heinz van Saanen. + void do_skill_level(Move* best, Move* ponder) { assert(MultiPV > 1); @@ -1992,9 +1936,9 @@ split_point_start: // At split points actual search starts from here // Rml list is already sorted by score in descending order int s; int max_s = -VALUE_INFINITE; - int size = Min(MultiPV, (int)Rml.size()); + int size = std::min(MultiPV, (int)Rml.size()); int max = Rml[0].score; - int var = Min(max - Rml[size - 1].score, PawnValueMidgame); + int var = std::min(max - Rml[size - 1].score, int(PawnValueMidgame)); int wk = 120 - 2 * SkillLevel; // PRNG sequence should be non deterministic @@ -2061,6 +2005,7 @@ split_point_start: // At split points actual search starts from here return NULL; } + // extract_pv_from_tt() builds a PV by adding moves from the transposition table. // We consider also failing high nodes and not only VALUE_TYPE_EXACT nodes. This // allow to always have a ponder move even when we fail high at root and also a @@ -2073,7 +2018,7 @@ split_point_start: // At split points actual search starts from here int ply = 1; Move m = pv[0]; - assert(m != MOVE_NONE && pos.move_is_pl(m)); + assert(m != MOVE_NONE && pos.is_pseudo_legal(m)); pv.clear(); pv.push_back(m); @@ -2081,7 +2026,7 @@ split_point_start: // At split points actual search starts from here while ( (tte = TT.probe(pos.get_key())) != NULL && tte->move() != MOVE_NONE - && pos.move_is_pl(tte->move()) + && pos.is_pseudo_legal(tte->move()) && pos.pl_move_is_legal(tte->move(), pos.pinned_pieces()) && ply < PLY_MAX && (!pos.is_draw() || ply < 2)) @@ -2095,6 +2040,7 @@ split_point_start: // At split points actual search starts from here do pos.undo_move(pv[--ply]); while (ply); } + // insert_pv_in_tt() is called at the end of a search iteration, and inserts // the PV back into the TT. This makes sure the old PV moves are searched // first, even if the old TT entries have been overwritten. @@ -2107,7 +2053,7 @@ split_point_start: // At split points actual search starts from here Value v, m = VALUE_NONE; int ply = 0; - assert(pv[0] != MOVE_NONE && pos.move_is_pl(pv[0])); + assert(pv[0] != MOVE_NONE && pos.is_pseudo_legal(pv[0])); do { k = pos.get_key(); @@ -2125,22 +2071,8 @@ split_point_start: // At split points actual search starts from here do pos.undo_move(pv[--ply]); while (ply); } -} // namespace - -// Little helper used by idle_loop() to check that all the slaves of a -// master thread have finished searching. - -static bool all_slaves_finished(SplitPoint* sp) { - - assert(sp); - - for (int i = 0; i < Threads.size(); i++) - if (sp->is_slave[i]) - return false; - - return true; -} +} // namespace // Thread::idle_loop() is where the thread is parked when it has no work to do. @@ -2155,23 +2087,22 @@ void Thread::idle_loop(SplitPoint* sp) { // instead of wasting CPU time polling for work. while ( do_sleep || do_terminate - || (Threads.use_sleeping_threads() && state == Thread::AVAILABLE)) + || (Threads.use_sleeping_threads() && !is_searching)) { assert((!sp && threadID) || Threads.use_sleeping_threads()); - // Grab the lock to avoid races with Thread::wake_up() - lock_grab(&sleepLock); - // Slave thread should exit as soon as do_terminate flag raises if (do_terminate) { assert(!sp); - lock_release(&sleepLock); return; } + // Grab the lock to avoid races with Thread::wake_up() + lock_grab(&sleepLock); + // If we are master and all slaves have finished don't go to sleep - if (sp && all_slaves_finished(sp)) + if (sp && Threads.split_point_finished(sp)) { lock_release(&sleepLock); break; @@ -2181,19 +2112,17 @@ void Thread::idle_loop(SplitPoint* sp) { // particular we need to avoid a deadlock in case a master thread has, // in the meanwhile, allocated us and sent the wake_up() call before we // had the chance to grab the lock. - if (do_sleep || state == Thread::AVAILABLE) + if (do_sleep || !is_searching) cond_wait(&sleepCond, &sleepLock); lock_release(&sleepLock); } // If this thread has been assigned work, launch a search - if (state == Thread::WORKISWAITING) + if (is_searching) { assert(!do_terminate); - state = Thread::SEARCHING; - // Copy split point position and search stack and call search() SearchStack ss[PLY_MAX_PLUS_2]; SplitPoint* tsp = splitPoint; @@ -2211,21 +2140,21 @@ void Thread::idle_loop(SplitPoint* sp) { else assert(false); - assert(state == Thread::SEARCHING); + assert(is_searching); - state = Thread::AVAILABLE; + is_searching = false; // Wake up master thread so to allow it to return from the idle loop in // case we are the last slave of the split point. if ( Threads.use_sleeping_threads() && threadID != tsp->master - && Threads[tsp->master].state == Thread::AVAILABLE) + && !Threads[tsp->master].is_searching) Threads[tsp->master].wake_up(); } // If this thread is the master of a split point and all slaves have // finished their work at this split point, return from the idle loop. - if (sp && all_slaves_finished(sp)) + if (sp && Threads.split_point_finished(sp)) { // Because sp->is_slave[] is reset under lock protection, // be sure sp->lock has been released before to return. @@ -2235,3 +2164,61 @@ void Thread::idle_loop(SplitPoint* sp) { } } } + + +// do_uci_async_cmd() is called by listener thread when in async mode and 'cmd' +// input line is received from the GUI. + +void do_uci_async_cmd(const std::string& cmd) { + + if (cmd == "quit") + QuitRequest = StopRequest = true; + + else if (cmd == "stop") + StopRequest = true; + + else if (cmd == "ponderhit") + { + // The opponent has played the expected move. GUI sends "ponderhit" if + // we were told to ponder on the same move the opponent has played. We + // should continue searching but switching from pondering to normal search. + Limits.ponder = false; + + if (StopOnPonderhit) + StopRequest = true; + } +} + + +// do_timer_event() is called by the timer thread when the timer triggers + +void do_timer_event() { + + static int lastInfoTime; + int e = elapsed_search_time(); + + // Print debug information every second + if (get_system_time() - lastInfoTime >= 1000) + { + lastInfoTime = get_system_time(); + + dbg_print_mean(); + dbg_print_hit_rate(); + } + + // Should we stop the search? + if (Limits.ponder) + return; + + bool stillAtFirstMove = FirstRootMove + && !AspirationFailLow + && e > TimeMgr.available_time(); + + bool noMoreTime = e > TimeMgr.maximum_time() + || stillAtFirstMove; + + if ( (Limits.useTimeManagement() && noMoreTime) + || (Limits.maxTime && e >= Limits.maxTime) + /* missing nodes limit */ ) // FIXME + StopRequest = true; +}