X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=fefc886424e9935116191a27c44594b7ad6d887b;hp=33e170acb8364fca92117ee63e881b1bcaf1ad98;hb=d58176bfead421088bb3543b3cb6d1c359a3c91b;hpb=969ad8001c12adfeb55b494e2bc3981364c8bf5e diff --git a/src/search.cpp b/src/search.cpp index 33e170ac..fefc8864 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -20,10 +20,11 @@ #include #include #include -#include +#include #include #include #include +#include #include "book.h" #include "evaluate.h" @@ -40,6 +41,7 @@ using std::cout; using std::endl; +using std::string; namespace { @@ -47,41 +49,34 @@ namespace { const bool FakeSplit = false; // Different node types, used as template parameter - enum NodeType { Root, PV, NonPV, SplitPointPV, SplitPointNonPV }; + enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV }; // RootMove struct is used for moves at the root of the tree. For each root - // move, we store two scores, a node count, and a PV (really a refutation - // in the case of moves which fail low). Value pv_score is normally set at - // -VALUE_INFINITE for all non-pv moves, while non_pv_score is computed - // according to the order in which moves are returned by MovePicker. + // move, we store a score, a node count, and a PV (really a refutation + // in the case of moves which fail low). Score is normally set at + // -VALUE_INFINITE for all non-pv moves. struct RootMove { - RootMove(); - RootMove(const RootMove& rm) { *this = rm; } - RootMove& operator=(const RootMove& rm); - // RootMove::operator<() is the comparison function used when // sorting the moves. A move m1 is considered to be better - // than a move m2 if it has an higher pv_score, or if it has - // equal pv_score but m1 has the higher non_pv_score. In this way - // we are guaranteed that PV moves are always sorted as first. - bool operator<(const RootMove& m) const { - return pv_score != m.pv_score ? pv_score < m.pv_score - : non_pv_score < m.non_pv_score; - } + // than a move m2 if it has an higher score + bool operator<(const RootMove& m) const { return score < m.score; } void extract_pv_from_tt(Position& pos); void insert_pv_in_tt(Position& pos); int64_t nodes; - Value pv_score; - Value non_pv_score; - Move pv[PLY_MAX_PLUS_2]; + Value score; + Value prevScore; + std::vector pv; }; // RootMoveList struct is mainly a std::vector of RootMove objects struct RootMoveList : public std::vector { + void init(Position& pos, Move searchMoves[]); + RootMove* find(const Move& m, int startIndex = 0); + int bestMoveChanges; }; @@ -134,7 +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; } @@ -150,7 +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 @@ -164,26 +159,17 @@ namespace { RootMoveList Rml; // MultiPV mode - int MultiPV, UCIMultiPV; + 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. - bool SendSearchedNodes; - int NodesSincePoll; - int NodesBetweenPolls = 30000; - // History table History H; @@ -202,58 +188,39 @@ namespace { bool connected_moves(const Position& pos, Move m1, Move m2); 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 can_return_tt(const TTEntry* tte, Depth depth, 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); - 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); - std::string score_to_uci(Value v, Value alpha, Value beta); - std::string speed_to_uci(int64_t nodes); - std::string pv_to_uci(Move pv[], int pvNum); - std::string depth_to_uci(Depth depth); - void poll(const Position& pos); + 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 wait_for_stop_or_ponderhit(); // MovePickerExt template class extends MovePicker and allows to choose at compile // time the proper moves source according to the type of node. In the default case // we simply create and use a standard MovePicker object. - template struct MovePickerExt : public MovePicker { + template struct MovePickerExt : public MovePicker { MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) : MovePicker(p, ttm, d, h, ss, b) {} - - RootMove& current() { assert(false); return Rml[0]; } // Dummy, needed to compile }; // In case of a SpNode we use split point's shared MovePicker object as moves source - template<> struct MovePickerExt : public MovePickerExt { + template<> struct MovePickerExt : public MovePicker { MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) - : MovePickerExt(p, ttm, d, h, ss, b), mp(ss->sp->mp) {} + : MovePicker(p, ttm, d, h, ss, b), mp(ss->sp->mp) {} Move get_next_move() { return mp->get_next_move(); } MovePicker* mp; }; - template<> struct MovePickerExt : public MovePickerExt { - - MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) - : MovePickerExt(p, ttm, d, h, ss, b) {} - }; - - // In case of a Root node we use RootMoveList as moves source - template<> struct MovePickerExt : public MovePicker { - - MovePickerExt(const Position&, Move, Depth, const History&, SearchStack*, Value); - RootMove& current() { return Rml[cur]; } - Move get_next_move() { return ++cur < (int)Rml.size() ? Rml[cur].pv[0] : MOVE_NONE; } - - int cur; - }; - // Overload operator<<() to make it easier to print moves in a coordinate // notation compatible with UCI protocol. std::ostream& operator<<(std::ostream& os, Move m) { @@ -293,7 +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) @@ -309,16 +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 @@ -386,35 +353,24 @@ int64_t perft(Position& pos, Depth depth) { bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { - static Book book; + static Book book; // Define static to initialize the PRNG only once // Initialize global search-related variables - StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = SendSearchedNodes = false; - NodesSincePoll = 0; - current_search_time(get_system_time()); + StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = false; + elapsed_search_time(get_system_time()); Limits = limits; TimeMgr.init(Limits, pos.startpos_ply_counter()); // Set output steram in normal or chess960 mode 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()); + 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) @@ -425,6 +381,12 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { } } + // Set best timer interval to avoid lagging under time pressure + if (TimeMgr.available_time()) + Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 8, 20))); + else + Threads.set_timer(100); + // Read UCI options UCIMultiPV = Options["MultiPV"].value(); SkillLevel = Options["Skill Level"].value(); @@ -432,8 +394,7 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { read_evaluation_uci_options(pos.side_to_move()); Threads.read_uci_options(); - // If needed allocate pawn and material hash tables and adjust TT size - Threads.init_hash_tables(); + // Set a new TT size if changed TT.set_size(Options["Hash"].value()); if (Options["Clear Hash"].value()) @@ -445,7 +406,7 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { // 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); // Wake up needed threads and reset maxPly counter for (int i = 0; i < Threads.size(); i++) @@ -457,42 +418,48 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { // Write to log file and keep it open to be accessed during the search if (Options["Use Search Log"].value()) { - std::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; + 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; } + // 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); + Threads.set_timer(0); + // Write final search statistics and close log file - if (LogFile.is_open()) + 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); + // From now on any UCI command will be read in-sync with Threads.getline() + Threads.stop_listener(); + // 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)) @@ -533,8 +500,8 @@ namespace { H.clear(); *ponderMove = bestMove = easyMove = skillBest = skillPonder = MOVE_NONE; depth = aspirationDelta = 0; - alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; - ss->currentMove = MOVE_NULL; // Hack to skip update_gains() + value = 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); @@ -551,65 +518,109 @@ namespace { // Iterative deepening loop until requested to stop or target depth reached while (!StopRequest && ++depth <= PLY_MAX && (!Limits.maxDepth || depth <= Limits.maxDepth)) { + // 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; - // Calculate dynamic aspiration window based on previous iterations - if (MultiPV == 1 && depth >= 5 && abs(bestValues[depth - 1]) < VALUE_KNOWN_WIN) + // MultiPV loop. We perform a full root search for each PV line + for (MultiPVIdx = 0; MultiPVIdx < std::min(MultiPV, (int)Rml.size()); MultiPVIdx++) { - 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 = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize + // Calculate dynamic aspiration window based on previous iterations + 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]; - alpha = Max(bestValues[depth - 1] - aspirationDelta, -VALUE_INFINITE); - beta = Min(bestValues[depth - 1] + aspirationDelta, VALUE_INFINITE); - } + aspirationDelta = std::min(std::max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24); + aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize - // 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 calling update_gains() - value = search(pos, ss+1, alpha, beta, depth * ONE_PLY); - - // Write PV back 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); - - // Value cannot be trusted. Break out immediately! - 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, (int)Rml.size()); i++) - cout << "info" - << depth_to_uci(depth * ONE_PLY) - << score_to_uci(Rml[i].pv_score, alpha, beta) - << speed_to_uci(pos.nodes_searched()) - << pv_to_uci(Rml[i].pv, i + 1) << endl; - - // In case of failing high/low increase aspiration window and research, - // otherwise exit the fail high/low loop. - if (value >= beta) - { - beta = Min(beta + aspirationDelta, VALUE_INFINITE); - aspirationDelta += aspirationDelta / 2; + alpha = std::max(Rml[MultiPVIdx].prevScore - aspirationDelta, -VALUE_INFINITE); + beta = std::min(Rml[MultiPVIdx].prevScore + aspirationDelta, VALUE_INFINITE); } - else if (value <= alpha) + else { - AspirationFailLow = true; - StopOnPonderhit = false; - - alpha = Max(alpha - aspirationDelta, -VALUE_INFINITE); - aspirationDelta += aspirationDelta / 2; + alpha = -VALUE_INFINITE; + beta = VALUE_INFINITE; } - else - break; - } while (abs(value) < VALUE_KNOWN_WIN); + // 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 starts 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); + + // 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 && value > alpha && value < 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 <= MultiPVIdx; i++) + Rml[i].insert_pv_in_tt(pos); + + // 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. 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 ((value > alpha && value < 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(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) + { + beta = std::min(beta + aspirationDelta, VALUE_INFINITE); + aspirationDelta += aspirationDelta / 2; + } + else if (value <= alpha) + { + AspirationFailLow = true; + StopOnPonderhit = false; + + alpha = std::max(alpha - aspirationDelta, -VALUE_INFINITE); + aspirationDelta += aspirationDelta / 2; + } + else + break; + + } while (abs(value) < VALUE_KNOWN_WIN); + } // Collect info about search result bestMove = Rml[0].pv[0]; @@ -617,15 +628,18 @@ namespace { bestValues[depth] = value; 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) << endl; + if (Options["Use Search Log"].value()) + { + Log log(Options["Search Log Filename"].value()); + log << pretty_pv(pos, depth, value, elapsed_search_time(), &Rml[0].pv[0]) << endl; + } - // Init easyMove after first iteration or drop if differs from the best move - if (depth == 1 && (Rml.size() == 1 || Rml[0].pv_score > Rml[1].pv_score + EasyMoveMargin)) + // 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) easyMove = MOVE_NONE; @@ -633,22 +647,16 @@ namespace { // Check for some early stop condition if (!StopRequest && Limits.useTimeManagement()) { - // Stop search early when the last two iterations returned a mate score - if ( depth >= 5 - && abs(bestValues[depth]) >= VALUE_MATE_IN_PLY_MAX - && abs(bestValues[depth - 1]) >= VALUE_MATE_IN_PLY_MAX) - StopRequest = true; - - // 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 @@ -657,7 +665,7 @@ 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 @@ -693,9 +701,9 @@ namespace { template Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) { - const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV); - const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV); - const bool RootNode = (NT == Root); + const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV || NT == SplitPointRoot); + const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV || NT == SplitPointRoot); + const bool RootNode = (NT == Root || NT == SplitPointRoot); assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE); assert(beta > alpha && beta <= VALUE_INFINITE); @@ -711,7 +719,7 @@ namespace { Depth ext, newDepth; ValueType vt; Value bestValue, value, oldAlpha; - Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific + Value refinedValue, nullValue, futilityBase, futilityValue; bool isPvMove, inCheck, singularExtensionNode, givesCheck, captureOrPromotion, dangerous; int moveCount = 0, playedMoveCount = 0; Thread& thread = Threads[pos.thread()]; @@ -726,7 +734,7 @@ namespace { if (PvNode && thread.maxPly < ss->ply) thread.maxPly = ss->ply; - // Step 1. Initialize node. + // Step 1. Initialize node if (!SpNode) { ss->currentMove = ss->bestMove = threatMove = (ss+1)->excludedMove = MOVE_NONE; @@ -742,11 +750,17 @@ namespace { goto split_point_start; } + // Step 2. Check for aborted search and immediate draw + if (( StopRequest + || pos.is_draw() + || ss->ply > PLY_MAX) && !RootNode) + return VALUE_DRAW; + // 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; } @@ -757,17 +771,28 @@ namespace { excludedMove = ss->excludedMove; posKey = excludedMove ? pos.get_exclusion_key() : pos.get_key(); tte = TT.probe(posKey); - ttMove = 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 - // smooth experience in analysis mode. - if (tte && (PvNode ? tte->depth() >= depth && tte->type() == VALUE_TYPE_EXACT - : ok_to_use_TT(tte, depth, beta, ss->ply))) + // smooth experience in analysis mode. We don't probe at Root nodes otherwise + // we should also update RootMoveList to avoid bogus output. + if (!RootNode && tte && (PvNode ? tte->depth() >= depth && tte->type() == VALUE_TYPE_EXACT + : 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 @@ -787,8 +812,17 @@ 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 @@ -837,12 +871,12 @@ 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) { @@ -902,12 +936,7 @@ namespace { if (pos.pl_move_is_legal(move, ci.pinned)) { pos.do_move(move, st, ci, pos.move_gives_check(move, ci)); - - if (pos.is_draw() || ss->ply + 1 > PLY_MAX) - value = VALUE_DRAW; - else - value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth); - + value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth); pos.undo_move(move); if (value >= rbeta) return value; @@ -932,7 +961,7 @@ namespace { split_point_start: // At split points actual search starts from here // Initialize a MovePicker object for the current position - MovePickerExt mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); + MovePickerExt mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); CheckInfo ci(pos); ss->bestMove = MOVE_NONE; futilityBase = ss->eval + ss->evalMargin; @@ -955,11 +984,17 @@ 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, 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 if ((PvNode || SpNode) && !pos.pl_move_is_legal(move, ci.pinned)) continue; @@ -980,24 +1015,17 @@ split_point_start: // At split points actual search starts from here // Save the current node count before the move is searched nodes = pos.nodes_searched(); - // If it's time to send nodes info, do it here where we have the - // correct accumulated node counts searched by each thread. - if (SendSearchedNodes) - { - SendSearchedNodes = false; - cout << "info" << speed_to_uci(pos.nodes_searched()) << endl; - } - // For long searches send current move info to GUI - if (current_search_time() > 2000) + if (pos.thread() == 0 && elapsed_search_time() > 2000) cout << "info" << depth_to_uci(depth) - << " currmove " << move << " currmovenumber " << moveCount << endl; + << " currmove " << move + << " 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 ? 1 : depth <= ONE_PLY ? MAX_MOVES : MultiPV)); + 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); @@ -1037,7 +1065,7 @@ 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) @@ -1054,19 +1082,19 @@ split_point_start: // At split points actual search starts from here // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth, // but fixing this made program slightly weaker. Depth predictedDepth = newDepth - reduction(depth, moveCount); - futilityValueScaled = futilityBase + futility_margin(predictedDepth, moveCount) - + H.gain(pos.piece_on(move_from(move)), move_to(move)); + futilityValue = futilityBase + futility_margin(predictedDepth, moveCount) + + H.gain(pos.piece_on(move_from(move)), move_to(move)); - if (futilityValueScaled < beta) + if (futilityValue < beta) { if (SpNode) { lock_grab(&(sp->lock)); - if (futilityValueScaled > sp->bestValue) - sp->bestValue = bestValue = futilityValueScaled; + if (futilityValue > sp->bestValue) + sp->bestValue = bestValue = futilityValue; } - else if (futilityValueScaled > bestValue) - bestValue = futilityValueScaled; + else if (futilityValue > bestValue) + bestValue = futilityValue; continue; } @@ -1097,22 +1125,6 @@ split_point_start: // At split points actual search starts from here // Step 14. Make the move pos.do_move(move, st, ci, givesCheck); - // Step XX. Poll. Check if search should be aborted. - if (pos.thread() == 0 && ++NodesSincePoll > NodesBetweenPolls) - { - NodesSincePoll = 0; - poll(pos); - } - - // Step XX. Check for aborted search and immediate draw - if ( StopRequest - || pos.is_draw() - || ss->ply + 1 > PLY_MAX) - { - value = VALUE_DRAW; - goto undo; - } - // Step extra. pv search (only in PV nodes) // The first move in list is the expected PV if (isPvMove) @@ -1127,7 +1139,7 @@ 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) @@ -1159,7 +1171,6 @@ split_point_start: // At split points actual search starts from here } // Step 17. Undo move -undo: pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1172,89 +1183,73 @@ undo: alpha = sp->alpha; } - if (value > bestValue) + // Finished searching the move. If StopRequest is true, the search + // was aborted because the user interrupted the search or because we + // ran out of time. In this case, the return value of the search cannot + // be trusted, and we don't update the best move and/or PV. + if (RootNode && !StopRequest) { - bestValue = value; - ss->bestMove = move; - - if ( !RootNode - && PvNode - && value > alpha - && value < beta) // We want always alpha < beta - alpha = value; - - if (SpNode && !thread.cutoff_occurred()) - { - sp->bestValue = value; - sp->ss->bestMove = move; - sp->alpha = alpha; - sp->is_betaCutoff = (value >= beta); - } - } - - if (RootNode) - { - // Finished searching the move. If StopRequest is true, the search - // was aborted because the user interrupted the search or because we - // ran out of time. In this case, the return value of the search cannot - // be trusted, and we break out of the loop without updating the best - // move and/or PV. - if (StopRequest) - break; - // Remember searched nodes counts for this move - mp.current().nodes += pos.nodes_searched() - nodes; + RootMove* rm = Rml.find(move); + rm->nodes += pos.nodes_searched() - nodes; // PV move or new best move ? if (isPvMove || value > alpha) { // Update PV - mp.current().pv_score = value; - mp.current().extract_pv_from_tt(pos); + rm->score = value; + rm->extract_pv_from_tt(pos); // We record how often the best move has been changed in each // iteration. This information is used for time management: When // the best move changes frequently, we allocate some more time. if (!isPvMove && MultiPV == 1) Rml.bestMoveChanges++; - - // 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(), Rml.begin() + moveCount); - - // Update alpha. In multi-pv we don't use aspiration window, so set - // alpha equal to minimum score among the PV lines searched so far. - if (MultiPV > 1) - alpha = Rml[Min(moveCount, MultiPV) - 1].pv_score; - else if (value > alpha) - alpha = value; } else // All other moves but the PV are set to the lowest value, this // is not a problem when sorting becuase sort is stable and move // position in the list is preserved, just the PV is pushed up. - mp.current().pv_score = -VALUE_INFINITE; + rm->score = -VALUE_INFINITE; } // RootNode + if (value > bestValue) + { + bestValue = value; + ss->bestMove = move; + + if ( PvNode + && value > alpha + && value < beta) // We want always alpha < beta + alpha = value; + + if (SpNode && !thread.cutoff_occurred()) + { + sp->bestValue = value; + sp->ss->bestMove = move; + sp->alpha = alpha; + sp->is_betaCutoff = (value >= beta); + } + } + // Step 19. Check for split - if ( !RootNode - && !SpNode + if ( !SpNode && depth >= Threads.min_split_depth() && bestValue < beta && Threads.available_slave_exists(pos.thread()) && !StopRequest && !thread.cutoff_occurred()) - Threads.split(pos, ss, &alpha, beta, &bestValue, depth, - threatMove, moveCount, &mp, PvNode); + bestValue = Threads.split(pos, ss, alpha, beta, bestValue, depth, + threatMove, moveCount, &mp, NT); } // 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; @@ -1271,7 +1266,7 @@ undo: // 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]) { @@ -1317,6 +1312,7 @@ undo: bool inCheck, enoughMaterial, givesCheck, evasionPrunable; const TTEntry* tte; Depth ttDepth; + ValueType vt; Value oldAlpha = alpha; ss->bestMove = ss->currentMove = MOVE_NONE; @@ -1337,7 +1333,7 @@ undo: tte = TT.probe(pos.get_key()); ttMove = (tte ? tte->move() : MOVE_NONE); - if (!PvNode && tte && ok_to_use_TT(tte, ttDepth, beta, ss->ply)) + if (!PvNode && tte && can_return_tt(tte, ttDepth, beta, ss->ply)) { ss->bestMove = ttMove; // Can be MOVE_NONE return value_from_tt(tte->value(), ss->ply); @@ -1387,10 +1383,10 @@ undo: CheckInfo ci(pos); // Loop through the moves until no moves remain or a beta cutoff occurs - while ( alpha < beta + 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); @@ -1400,17 +1396,18 @@ undo: && !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 < alpha) + if (futilityValue < beta) { if (futilityValue > bestValue) bestValue = futilityValue; + continue; } @@ -1425,14 +1422,14 @@ undo: 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; @@ -1441,7 +1438,7 @@ undo: && !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)) { @@ -1469,11 +1466,12 @@ undo: if (value > bestValue) { bestValue = value; - if (value > alpha) - { + ss->bestMove = move; + + if ( PvNode + && value > alpha + && value < beta) // We want always alpha < beta alpha = value; - ss->bestMove = move; - } } } @@ -1483,8 +1481,11 @@ undo: return value_mated_in(ss->ply); // Update transposition table - ValueType vt = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT); - TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, ss->bestMove, ss->eval, evalMargin); + move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove; + vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER + : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT; + + TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1506,7 +1507,7 @@ undo: 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); @@ -1522,7 +1523,7 @@ undo: 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; @@ -1532,7 +1533,7 @@ undo: 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 @@ -1561,8 +1562,8 @@ undo: 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); @@ -1637,10 +1638,10 @@ undo: 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; @@ -1655,9 +1656,9 @@ undo: // 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; @@ -1672,16 +1673,16 @@ undo: } - // ok_to_use_TT() returns true if a transposition table score - // can be used at a given point in search. + // can_return_tt() returns true if a transposition table score + // can be used to cut-off at a given point in search. - bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply) { + bool can_return_tt(const TTEntry* tte, Depth depth, Value beta, int ply) { 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)); @@ -1726,24 +1727,10 @@ undo: } - // 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; @@ -1761,7 +1748,7 @@ undo: // mate Mate in y moves, not plies. If the engine is getting mated // use negative values for y. - std::string score_to_uci(Value v, Value alpha, Value beta) { + string score_to_uci(Value v, Value alpha, Value beta) { std::stringstream s; @@ -1779,10 +1766,10 @@ undo: // speed_to_uci() returns a string with time stats of current search suitable // to be sent to UCI gui. - std::string speed_to_uci(int64_t nodes) { + 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) @@ -1794,11 +1781,11 @@ undo: // pv_to_uci() returns a string with information on the current PV line // formatted according to UCI specification. - std::string pv_to_uci(Move pv[], int pvNum) { + string pv_to_uci(const Move pv[], int pvNum, bool chess960) { std::stringstream s; - s << " multipv " << pvNum << " pv "; + s << " multipv " << pvNum << " pv " << set960(chess960); for ( ; *pv != MOVE_NONE; pv++) s << *pv << " "; @@ -1809,7 +1796,7 @@ undo: // depth_to_uci() returns a string with information on the current depth and // seldepth formatted according to UCI specification. - std::string depth_to_uci(Depth depth) { + string depth_to_uci(Depth depth) { std::stringstream s; @@ -1824,83 +1811,88 @@ undo: return s.str(); } + string time_to_string(int millisecs) { - // 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. + const int MSecMinute = 1000 * 60; + const int MSecHour = 1000 * 60 * 60; - void poll(const Position& pos) { + int hours = millisecs / MSecHour; + int minutes = (millisecs % MSecHour) / MSecMinute; + int seconds = ((millisecs % MSecHour) % MSecMinute) / 1000; - static int lastInfoTime; - int t = current_search_time(); + std::stringstream s; - // Poll for input - if (input_available()) - { - // We are line oriented, don't read single chars - std::string command; + if (hours) + s << hours << ':'; - 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; + s << std::setfill('0') << std::setw(2) << minutes << ':' << std::setw(2) << seconds; + return s.str(); + } - if (StopOnPonderhit) - StopRequest = true; - } - } + string score_to_string(Value v) { - // Print search information - if (t < 1000) - lastInfoTime = 0; + std::stringstream s; - 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; + if (v >= VALUE_MATE_IN_PLY_MAX) + s << "#" << (VALUE_MATE - v + 1) / 2; + else if (v <= VALUE_MATED_IN_PLY_MAX) + s << "-#" << (VALUE_MATE + v) / 2; + else + s << std::setprecision(2) << std::fixed << std::showpos << float(v) / PawnValueMidgame; - else if (t - lastInfoTime >= 1000) - { - lastInfoTime = t; + return s.str(); + } - dbg_print_mean(); - dbg_print_hit_rate(); + // 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"). - // Send info on searched nodes as soon as we return to root - SendSearchedNodes = true; - } + string pretty_pv(Position& pos, int depth, Value value, int time, Move pv[]) { + + const int64_t K = 1000; + const int64_t M = 1000000; + const int startColumn = 28; + const size_t maxLength = 80 - startColumn; + + StateInfo state[PLY_MAX_PLUS_2], *st = state; + Move* m = pv; + string san; + std::stringstream s; + size_t length = 0; + + // First print depth, score, time and searched nodes... + s << set960(pos.is_chess960()) + << std::setw(2) << depth + << std::setw(8) << score_to_string(value) + << std::setw(8) << time_to_string(time); + + if (pos.nodes_searched() < M) + s << std::setw(8) << pos.nodes_searched() / 1 << " "; + else if (pos.nodes_searched() < K * M) + s << std::setw(7) << pos.nodes_searched() / K << "K "; + else + s << std::setw(7) << pos.nodes_searched() / M << "M "; - // Should we stop the search? - if (Limits.ponder) - return; + // ...then print the full PV line in short algebraic notation + while (*m != MOVE_NONE) + { + san = move_to_san(pos, *m); + length += san.length() + 1; - bool stillAtFirstMove = FirstRootMove - && !AspirationFailLow - && t > TimeMgr.available_time(); + if (length > maxLength) + { + length = san.length() + 1; + s << "\n" + string(startColumn, ' '); + } + s << san << ' '; - bool noMoreTime = t > TimeMgr.maximum_time() - || stillAtFirstMove; + pos.do_move(*m++, *st++); + } + + // Restore original position before to leave + while (m != pv) pos.undo_move(*--m); - if ( (Limits.useTimeManagement() && noMoreTime) - || (Limits.maxTime && t >= Limits.maxTime) - || (Limits.maxNodes && pos.nodes_searched() >= Limits.maxNodes)) // FIXME - StopRequest = true; + return s.str(); } @@ -1913,14 +1905,14 @@ undo: void wait_for_stop_or_ponderhit() { - std::string command; + string cmd; // Wait for a command from stdin - while ( std::getline(std::cin, command) - && command != "ponderhit" && command != "stop" && command != "quit") {}; + while (cmd != "ponderhit" && cmd != "stop" && cmd != "quit") + Threads.getline(cmd); - if (command != "ponderhit" && command != "stop") - QuitRequest = true; // Must be "quit" or getline() returned false + if (cmd == "quit") + QuitRequest = true; } @@ -1932,12 +1924,12 @@ undo: static RKISS rk; - // Rml list is already sorted by pv_score in descending order + // 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 max = Rml[0].pv_score; - int var = Min(max - Rml[size - 1].pv_score, PawnValueMidgame); + int size = std::min(MultiPV, (int)Rml.size()); + int max = Rml[0].score; + int var = std::min(max - Rml[size - 1].score, int(PawnValueMidgame)); int wk = 120 - 2 * SkillLevel; // PRNG sequence should be non deterministic @@ -1949,10 +1941,10 @@ undo: // then we choose the move with the resulting highest score. for (int i = 0; i < size; i++) { - s = Rml[i].pv_score; + s = Rml[i].score; // Don't allow crazy blunders even at very low skills - if (i > 0 && Rml[i-1].pv_score > s + EasyMoveMargin) + if (i > 0 && Rml[i-1].score > s + EasyMoveMargin) break; // This is our magical formula @@ -1970,27 +1962,6 @@ undo: /// RootMove and RootMoveList method's definitions - RootMove::RootMove() { - - nodes = 0; - pv_score = non_pv_score = -VALUE_INFINITE; - pv[0] = MOVE_NONE; - } - - RootMove& RootMove::operator=(const RootMove& rm) { - - const Move* src = rm.pv; - Move* dst = pv; - - // Avoid a costly full rm.pv[] copy - do *dst++ = *src; while (*src++ != MOVE_NONE); - - nodes = rm.nodes; - pv_score = rm.pv_score; - non_pv_score = rm.non_pv_score; - return *this; - } - void RootMoveList::init(Position& pos, Move searchMoves[]) { Move* sm; @@ -2008,13 +1979,23 @@ undo: continue; RootMove rm; - rm.pv[0] = ml.move(); - rm.pv[1] = MOVE_NONE; - rm.pv_score = -VALUE_INFINITE; + rm.pv.push_back(ml.move()); + rm.pv.push_back(MOVE_NONE); + rm.score = rm.prevScore = -VALUE_INFINITE; + rm.nodes = 0; push_back(rm); } } + RootMove* RootMoveList::find(const Move& m, int startIndex) { + + for (size_t i = startIndex; i < size(); i++) + if ((*this)[i].pv[0] == m) + return &(*this)[i]; + + 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 @@ -2025,22 +2006,26 @@ undo: StateInfo state[PLY_MAX_PLUS_2], *st = state; TTEntry* tte; int ply = 1; + Move m = pv[0]; - assert(pv[0] != MOVE_NONE && pos.move_is_pl(pv[0])); + assert(m != MOVE_NONE && pos.is_pseudo_legal(m)); - pos.do_move(pv[0], *st++); + pv.clear(); + pv.push_back(m); + pos.do_move(m, *st++); 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)) { - pv[ply] = tte->move(); - pos.do_move(pv[ply++], *st++); + pv.push_back(tte->move()); + pos.do_move(tte->move(), *st++); + ply++; } - pv[ply] = MOVE_NONE; + pv.push_back(MOVE_NONE); do pos.undo_move(pv[--ply]); while (ply); } @@ -2057,7 +2042,7 @@ undo: 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(); @@ -2075,137 +2060,173 @@ undo: do pos.undo_move(pv[--ply]); while (ply); } +} // namespace - // Specializations for MovePickerExt in case of Root node - MovePickerExt::MovePickerExt(const Position& p, Move ttm, Depth d, - const History& h, SearchStack* ss, Value b) - : MovePicker(p, ttm, d, h, ss, b), cur(-1) { - Move move; - Value score = VALUE_ZERO; - - // Score root moves using standard ordering used in main search, the moves - // are scored according to the order in which they are returned by MovePicker. - // This is the second order score that is used to compare the moves when - // the first orders pv_score of both moves are equal. - while ((move = MovePicker::get_next_move()) != MOVE_NONE) - for (RootMoveList::iterator rm = Rml.begin(); rm != Rml.end(); ++rm) - if (rm->pv[0] == move) - { - rm->non_pv_score = score--; - break; - } - sort(Rml.begin(), Rml.end()); - } +// Little helper used by idle_loop() to check that all the slave threads of a +// split point have finished searching. -} // namespace +static bool all_slaves_finished(SplitPoint* sp) { + for (int i = 0; i < Threads.size(); i++) + if (sp->is_slave[i]) + return false; -// ThreadsManager::idle_loop() is where the threads are parked when they have no work -// to do. The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint -// object for which the current thread is the master. + return true; +} -void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) { - assert(threadID >= 0 && threadID < MAX_THREADS); +// Thread::idle_loop() is where the thread is parked when it has no work to do. +// The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint object +// for which the thread is the master. - int i; - bool allFinished; +void Thread::idle_loop(SplitPoint* sp) { while (true) { - // Slave threads can exit as soon as AllThreadsShouldExit raises, - // master should exit as last one. - if (allThreadsShouldExit) - { - assert(!sp); - threads[threadID].state = Thread::TERMINATED; - return; - } - - // If we are not thinking, wait for a condition to be signaled + // If we are not searching, wait for a condition to be signaled // instead of wasting CPU time polling for work. - while ( threadID >= activeThreads - || threads[threadID].state == Thread::INITIALIZING - || (useSleepingThreads && threads[threadID].state == Thread::AVAILABLE)) + while ( do_sleep + || do_terminate + || (Threads.use_sleeping_threads() && !is_searching)) { - assert(!sp || useSleepingThreads); - assert(threadID != 0 || useSleepingThreads); + assert((!sp && threadID) || Threads.use_sleeping_threads()); - if (threads[threadID].state == Thread::INITIALIZING) - threads[threadID].state = Thread::AVAILABLE; + // Slave thread should exit as soon as do_terminate flag raises + if (do_terminate) + { + assert(!sp); + return; + } // Grab the lock to avoid races with Thread::wake_up() - lock_grab(&threads[threadID].sleepLock); - - // If we are master and all slaves have finished do not go to sleep - for (i = 0; sp && i < activeThreads && !sp->is_slave[i]; i++) {} - allFinished = (i == activeThreads); + lock_grab(&sleepLock); - if (allFinished || allThreadsShouldExit) + // If we are master and all slaves have finished don't go to sleep + if (sp && all_slaves_finished(sp)) { - lock_release(&threads[threadID].sleepLock); + lock_release(&sleepLock); break; } - // Do sleep here after retesting sleep conditions - if (threadID >= activeThreads || threads[threadID].state == Thread::AVAILABLE) - cond_wait(&threads[threadID].sleepCond, &threads[threadID].sleepLock); + // Do sleep after retesting sleep conditions under lock protection, in + // 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 || !is_searching) + cond_wait(&sleepCond, &sleepLock); - lock_release(&threads[threadID].sleepLock); + lock_release(&sleepLock); } // If this thread has been assigned work, launch a search - if (threads[threadID].state == Thread::WORKISWAITING) + if (is_searching) { - assert(!allThreadsShouldExit); - - threads[threadID].state = Thread::SEARCHING; + assert(!do_terminate); // Copy split point position and search stack and call search() - // with SplitPoint template parameter set to true. SearchStack ss[PLY_MAX_PLUS_2]; - SplitPoint* tsp = threads[threadID].splitPoint; + SplitPoint* tsp = splitPoint; Position pos(*tsp->pos, threadID); memcpy(ss, tsp->ss - 1, 4 * sizeof(SearchStack)); (ss+1)->sp = tsp; - if (tsp->pvNode) + if (tsp->nodeType == Root) + search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); + else if (tsp->nodeType == PV) search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); - else + else if (tsp->nodeType == NonPV) search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); + else + assert(false); - assert(threads[threadID].state == Thread::SEARCHING); + assert(is_searching); - threads[threadID].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 ( useSleepingThreads + if ( Threads.use_sleeping_threads() && threadID != tsp->master - && threads[tsp->master].state == Thread::AVAILABLE) - threads[tsp->master].wake_up(); + && !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. - for (i = 0; sp && i < activeThreads && !sp->is_slave[i]; i++) {} - allFinished = (i == activeThreads); - - if (allFinished) + if (sp && all_slaves_finished(sp)) { - // Because sp->slaves[] is reset under lock protection, + // Because sp->is_slave[] is reset under lock protection, // be sure sp->lock has been released before to return. lock_grab(&(sp->lock)); lock_release(&(sp->lock)); - - // In helpful master concept a master can help only a sub-tree, and - // because here is all finished is not possible master is booked. - assert(threads[threadID].state == Thread::AVAILABLE); - - threads[threadID].state = Thread::SEARCHING; return; } } } + + +// 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") + { + // Quit the program as soon as possible + Limits.ponder = false; + QuitRequest = StopRequest = true; + } + else if (cmd == "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 (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; +}