X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=eb19b51d9c994c5d11e8c9c7abfb195806e475af;hp=e853b6ee73e2518490c590283ef10b926efea42c;hb=9ba7f701ead00fd4a59841d457d15a15d3b84378;hpb=dee878082960be198fdb1493940b3d8a2be0bd58 diff --git a/src/search.cpp b/src/search.cpp index e853b6ee..eb19b51d 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -28,15 +28,16 @@ #include #include #include +#include #include "book.h" #include "evaluate.h" #include "history.h" #include "misc.h" +#include "move.h" #include "movegen.h" #include "movepick.h" #include "lock.h" -#include "san.h" #include "search.h" #include "timeman.h" #include "thread.h" @@ -104,55 +105,51 @@ namespace { }; - // RootMove struct is used for moves at the root at the tree. For each - // root move, we store a score, a node count, and a PV (really a refutation - // in the case of moves which fail low). + // RootMove struct is used for moves at the root at 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. struct RootMove { - RootMove() : mp_score(0), nodes(0) {} + 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 a higher score, or if the moves - // have equal score but m1 has the higher beta cut-off count. + // 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 score != m.score ? score < m.score : mp_score <= m.mp_score; + return pv_score != m.pv_score ? pv_score < m.pv_score + : non_pv_score < m.non_pv_score; } - Move move; - Value score; - int mp_score; + void extract_pv_from_tt(Position& pos); + void insert_pv_in_tt(Position& pos); + std::string pv_info_to_uci(Position& pos, Depth depth, Value alpha, Value beta, int pvLine = 0); + int64_t nodes; + Value pv_score; + Value non_pv_score; Move pv[PLY_MAX_PLUS_2]; }; - // The RootMoveList class is essentially an array of RootMove objects, with - // a handful of methods for accessing the data in the individual moves. - - class RootMoveList { + // RootMoveList struct is essentially a std::vector<> of RootMove objects, + // with an handful of methods above the standard ones. - public: - RootMoveList(Position& pos, Move searchMoves[]); + struct RootMoveList : public std::vector { - Move move(int moveNum) const { return moves[moveNum].move; } - Move move_pv(int moveNum, int i) const { return moves[moveNum].pv[i]; } - int move_count() const { return count; } - Value move_score(int moveNum) const { return moves[moveNum].score; } - int64_t move_nodes(int moveNum) const { return moves[moveNum].nodes; } - void add_move_nodes(int moveNum, int64_t nodes) { moves[moveNum].nodes += nodes; } - void set_move_score(int moveNum, Value score) { moves[moveNum].score = score; } + typedef std::vector Base; - void set_move_pv(int moveNum, const Move pv[]); - void score_moves(const Position& pos); - void sort(); - void sort_multipv(int n); + void init(Position& pos, Move searchMoves[]); + void sort() { insertion_sort(begin(), end()); } + void sort_multipv(int n) { insertion_sort(begin(), begin() + n); } - private: - RootMove moves[MOVES_MAX]; - int count; + int bestMoveChanges; }; @@ -164,13 +161,22 @@ namespace { // operator<<() that will use it to properly format castling moves. enum set960 {}; - std::ostream& operator<< (std::ostream& os, const set960& m) { + std::ostream& operator<< (std::ostream& os, const set960& f) { - os.iword(0) = int(m); + os.iword(0) = int(f); return os; } + // Overload operator << for moves to make it easier to print moves in + // coordinate notation compatible with UCI protocol. + std::ostream& operator<<(std::ostream& os, Move m) { + + bool chess960 = (os.iword(0) != 0); // See set960() + return os << move_to_uci(m, chess960); + } + + /// Adjustments // Step 6. Razoring @@ -197,8 +203,8 @@ namespace { // Extensions. Configurable UCI options // Array index 0 is used at non-PV nodes, index 1 at PV nodes. - Depth CheckExtension[2], SingleEvasionExtension[2], PawnPushTo7thExtension[2]; - Depth PassedPawnExtension[2], PawnEndgameExtension[2], MateThreatExtension[2]; + Depth CheckExtension[2], PawnPushTo7thExtension[2], PassedPawnExtension[2]; + Depth PawnEndgameExtension[2], MateThreatExtension[2]; // Minimum depth for use of singular extension const Depth SingularExtensionDepth[2] = { 8 * ONE_PLY /* non-PV */, 6 * ONE_PLY /* PV */}; @@ -227,11 +233,6 @@ namespace { template inline Depth reduction(Depth d, int mn) { return (Depth) ReductionMatrix[PV][Min(d / 2, 63)][Min(mn, 63)]; } - // Common adjustments - - // Search depth at iteration 1 - const Depth InitialDepth = ONE_PLY; - // Easy move margin. An easy move candidate must be at least this much // better than the second best move. const Value EasyMoveMargin = Value(0x200); @@ -242,23 +243,16 @@ namespace { // Book object Book OpeningBook; - // Iteration counter - int Iteration; - - // Scores and number of times the best move changed for each iteration - Value ValueByIteration[PLY_MAX_PLUS_2]; - int BestMoveChangesByIteration[PLY_MAX_PLUS_2]; - - // Search window management - int AspirationDelta; + // Root move list + RootMoveList Rml; // MultiPV mode int MultiPV; // Time managment variables int SearchStartTime, MaxNodes, MaxDepth, ExactMaxTime; - bool UseTimeManagement, InfiniteSearch, PonderSearch, StopOnPonderhit; - bool FirstRootMove, AbortSearch, Quit, AspirationFailLow; + bool UseTimeManagement, InfiniteSearch, Pondering, StopOnPonderhit; + bool FirstRootMove, StopRequest, QuitRequest, AspirationFailLow; TimeManager TimeMgr; // Log file @@ -270,6 +264,7 @@ namespace { // 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; @@ -278,10 +273,9 @@ namespace { /// Local functions - Value id_loop(Position& pos, Move searchMoves[]); - Value root_search(Position& pos, SearchStack* ss, Move* pv, RootMoveList& rml, Value* alphaPtr, Value* betaPtr); + Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove); - template + template Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply); template @@ -291,11 +285,11 @@ namespace { inline Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) { return depth < ONE_PLY ? qsearch(pos, ss, alpha, beta, DEPTH_ZERO, ply) - : search(pos, ss, alpha, beta, depth, ply); + : search(pos, ss, alpha, beta, depth, ply); } template - Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool singleEvasion, bool mateThreat, bool* dangerous); + Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool mateThreat, bool* dangerous); bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta, Value *bValue); bool connected_moves(const Position& pos, Move m1, Move m2); @@ -306,19 +300,15 @@ 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_killers(Move m, SearchStack* ss); + void update_killers(Move m, Move killers[]); void update_gains(const Position& pos, Move move, Value before, Value after); + void qsearch_scoring(Position& pos, MoveStack* mlist, MoveStack* last); int current_search_time(); std::string value_to_uci(Value v); int nps(const Position& pos); void poll(const Position& pos); - void ponderhit(); void wait_for_stop_or_ponderhit(); - void init_ss_array(SearchStack* ss, int size); - void print_pv_info(const Position& pos, Move pv[], Value alpha, Value beta, Value value); - void insert_pv_in_tt(const Position& pos, Move pv[]); - void extract_pv_from_tt(const Position& pos, Move bestMove, Move pv[]); #if !defined(_MSC_VER) void* init_thread(void* threadID); @@ -326,7 +316,73 @@ namespace { DWORD WINAPI init_thread(LPVOID threadID); #endif -} + + // MovePickerExt is an extended MovePicker used to choose at compile time + // the proper move source according to the type of node. + template struct MovePickerExt; + + // In Root nodes use RootMoveList Rml as source. Score and sort the root moves + // before to search them. + 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), firstCall(true) { + Move move; + Value score = VALUE_ZERO; + + // Score root moves using the standard way used in main search, the moves + // are scored according to the order in which are returned by MovePicker. + // This is the second order score that is used to compare the moves when + // the first order pv scores of both moves are equal. + while ((move = MovePicker::get_next_move()) != MOVE_NONE) + for (rm = Rml.begin(); rm != Rml.end(); ++rm) + if (rm->pv[0] == move) + { + rm->non_pv_score = score--; + break; + } + + Rml.sort(); + rm = Rml.begin(); + } + + Move get_next_move() { + + if (!firstCall) + ++rm; + else + firstCall = false; + + return rm != Rml.end() ? rm->pv[0] : MOVE_NONE; + } + + RootMoveList::iterator rm; + bool firstCall; + }; + + // In SpNodes use split point's shared MovePicker object as move source + 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), + mp(ss->sp->mp) {} + + Move get_next_move() { return mp->get_next_move(); } + + RootMoveList::iterator rm; // Dummy, needed to compile + MovePicker* mp; + }; + + // Default case, create and use a MovePicker object as source + 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) {} + + RootMoveList::iterator rm; // Dummy, needed to compile + }; + +} // namespace //// @@ -370,15 +426,15 @@ void init_search() { /// perft() is our utility to verify move generation is bug free. All the legal /// moves up to given depth are generated and counted and the sum returned. -int perft(Position& pos, Depth depth) +int64_t perft(Position& pos, Depth depth) { MoveStack mlist[MOVES_MAX]; StateInfo st; Move m; - int sum = 0; + int64_t sum = 0; // Generate all legal moves - MoveStack* last = generate_moves(pos, mlist); + MoveStack* last = generate(pos, mlist); // If we are at the last ply we don't need to do and undo // the moves, just to count them. @@ -400,37 +456,37 @@ int perft(Position& pos, Depth depth) /// think() is the external interface to Stockfish's search, and is called when /// the program receives the UCI 'go' command. It initializes various -/// search-related global variables, and calls root_search(). It returns false +/// search-related global variables, and calls id_loop(). It returns false /// when a quit command is received during the search. bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[], int movesToGo, int maxDepth, int maxNodes, int maxTime, Move searchMoves[]) { // Initialize global search variables - StopOnPonderhit = AbortSearch = Quit = AspirationFailLow = false; + StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = SendSearchedNodes = false; NodesSincePoll = 0; SearchStartTime = get_system_time(); ExactMaxTime = maxTime; MaxDepth = maxDepth; MaxNodes = maxNodes; InfiniteSearch = infinite; - PonderSearch = ponder; + Pondering = ponder; UseTimeManagement = !ExactMaxTime && !MaxDepth && !MaxNodes && !InfiniteSearch; // Look for a book move, only during games, not tests if (UseTimeManagement && Options["OwnBook"].value()) { - if (Options["Book File"].value() != OpeningBook.file_name()) + if (Options["Book File"].value() != OpeningBook.name()) OpeningBook.open(Options["Book File"].value()); Move bookMove = OpeningBook.get_move(pos, Options["Best Book Move"].value()); if (bookMove != MOVE_NONE) { - if (PonderSearch) + if (Pondering) wait_for_stop_or_ponderhit(); cout << "bestmove " << bookMove << endl; - return true; + return !QuitRequest; } } @@ -444,8 +500,6 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[ CheckExtension[1] = Options["Check Extension (PV nodes)"].value(); CheckExtension[0] = Options["Check Extension (non-PV nodes)"].value(); - SingleEvasionExtension[1] = Options["Single Evasion Extension (PV nodes)"].value(); - SingleEvasionExtension[0] = Options["Single Evasion Extension (non-PV nodes)"].value(); PawnPushTo7thExtension[1] = Options["Pawn Push to 7th Extension (PV nodes)"].value(); PawnPushTo7thExtension[0] = Options["Pawn Push to 7th Extension (non-PV nodes)"].value(); PassedPawnExtension[1] = Options["Passed Pawn Extension (PV nodes)"].value(); @@ -457,10 +511,7 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[ MultiPV = Options["MultiPV"].value(); UseLogFile = Options["Use Search Log"].value(); - if (UseLogFile) - LogFile.open(Options["Search Log Filename"].value().c_str(), std::ios::out | std::ios::app); - - read_weights(pos.side_to_move()); + read_evaluation_uci_options(pos.side_to_move()); // Set the number of active threads ThreadsMgr.read_uci_options(); @@ -489,465 +540,221 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[ // Write search information to log file if (UseLogFile) - LogFile << "Searching: " << pos.to_fen() << endl - << "infinite: " << infinite - << " ponder: " << ponder - << " time: " << myTime + { + std::string name = Options["Search Log Filename"].value(); + LogFile.open(name.c_str(), std::ios::out | std::ios::app); + + LogFile << "Searching: " << pos.to_fen() + << "\ninfinite: " << infinite + << " ponder: " << ponder + << " time: " << myTime << " increment: " << myIncrement << " moves to go: " << movesToGo << endl; + } // We're ready to start thinking. Call the iterative deepening loop function - id_loop(pos, searchMoves); + Move ponderMove = MOVE_NONE; + Move bestMove = id_loop(pos, searchMoves, &ponderMove); + + // Print final search statistics + cout << "info nodes " << pos.nodes_searched() + << " nps " << nps(pos) + << " time " << current_search_time() << endl; if (UseLogFile) + { + LogFile << "\nNodes: " << pos.nodes_searched() + << "\nNodes/second: " << nps(pos) + << "\nBest move: " << move_to_san(pos, bestMove); + + StateInfo st; + pos.do_move(bestMove, st); + LogFile << "\nPonder move: " + << move_to_san(pos, ponderMove) // Works also with MOVE_NONE + << endl; + + // Return from think() with unchanged position + pos.undo_move(bestMove); + LogFile.close(); + } // This makes all the threads to go to sleep ThreadsMgr.set_active_threads(1); - return !Quit; + // If we are pondering or in infinite search, we shouldn't print the + // best move before we are told to do so. + if (!StopRequest && (Pondering || InfiniteSearch)) + wait_for_stop_or_ponderhit(); + + // Could be both MOVE_NONE when searching on a stalemate position + cout << "bestmove " << bestMove << " ponder " << ponderMove << endl; + + return !QuitRequest; } namespace { - // id_loop() is the main iterative deepening loop. It calls root_search - // repeatedly with increasing depth until the allocated thinking time has - // been consumed, the user stops the search, or the maximum search depth is - // reached. + // id_loop() is the main iterative deepening loop. It calls search() repeatedly + // with increasing depth until the allocated thinking time has been consumed, + // user stops the search, or the maximum search depth is reached. - Value id_loop(Position& pos, Move searchMoves[]) { + Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove) { SearchStack ss[PLY_MAX_PLUS_2]; - Move pv[PLY_MAX_PLUS_2]; - Move EasyMove = MOVE_NONE; - Value value, alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; + Value bestValues[PLY_MAX_PLUS_2]; + int bestMoveChanges[PLY_MAX_PLUS_2]; + int iteration, researchCountFL, researchCountFH, aspirationDelta; + Value value, alpha, beta; + Depth depth; + Move bestMove, easyMove; + + // Moves to search are verified, scored and sorted + Rml.init(pos, searchMoves); - // Moves to search are verified, copied, scored and sorted - RootMoveList rml(pos, searchMoves); + // Initialize FIXME move before Rml.init() + TT.new_search(); + H.clear(); + memset(ss, 0, PLY_MAX_PLUS_2 * sizeof(SearchStack)); + alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; + *ponderMove = bestMove = easyMove = MOVE_NONE; + aspirationDelta = 0; + iteration = 1; + ss->currentMove = MOVE_NULL; // Hack to skip update_gains() // Handle special case of searching on a mate/stale position - if (rml.move_count() == 0) + if (Rml.size() == 0) { - if (PonderSearch) - wait_for_stop_or_ponderhit(); + cout << "info depth " << iteration << " score " + << value_to_uci(pos.is_check() ? -VALUE_MATE : VALUE_DRAW) + << endl; - return pos.is_check() ? -VALUE_MATE : VALUE_DRAW; + return MOVE_NONE; } - // Print RootMoveList startup scoring to the standard output, - // so to output information also for iteration 1. + // Send initial scoring (iteration 1) cout << set960(pos.is_chess960()) // Is enough to set once at the beginning - << "info depth " << 1 - << "\ninfo depth " << 1 - << " score " << value_to_uci(rml.move_score(0)) - << " time " << current_search_time() - << " nodes " << pos.nodes_searched() - << " nps " << nps(pos) - << " pv " << rml.move(0) << "\n"; - - // Initialize - TT.new_search(); - H.clear(); - init_ss_array(ss, PLY_MAX_PLUS_2); - pv[0] = pv[1] = MOVE_NONE; - ValueByIteration[1] = rml.move_score(0); - Iteration = 1; + << "info depth " << iteration + << "\n" << Rml[0].pv_info_to_uci(pos, ONE_PLY, alpha, beta) << endl; // Is one move significantly better than others after initial scoring ? - if ( rml.move_count() == 1 - || rml.move_score(0) > rml.move_score(1) + EasyMoveMargin) - EasyMove = rml.move(0); + if ( Rml.size() == 1 + || Rml[0].pv_score > Rml[1].pv_score + EasyMoveMargin) + easyMove = Rml[0].pv[0]; // Iterative deepening loop - while (Iteration < PLY_MAX) + while (++iteration <= PLY_MAX && (!MaxDepth || iteration <= MaxDepth) && !StopRequest) { - // Initialize iteration - Iteration++; - BestMoveChangesByIteration[Iteration] = 0; + cout << "info depth " << iteration << endl; - cout << "info depth " << Iteration << endl; + Rml.bestMoveChanges = researchCountFL = researchCountFH = 0; + depth = (iteration - 1) * ONE_PLY; // Calculate dynamic aspiration window based on previous iterations - if (MultiPV == 1 && Iteration >= 6 && abs(ValueByIteration[Iteration - 1]) < VALUE_KNOWN_WIN) + if (MultiPV == 1 && iteration >= 6 && abs(bestValues[iteration - 1]) < VALUE_KNOWN_WIN) { - int prevDelta1 = ValueByIteration[Iteration - 1] - ValueByIteration[Iteration - 2]; - int prevDelta2 = ValueByIteration[Iteration - 2] - ValueByIteration[Iteration - 3]; + int prevDelta1 = bestValues[iteration - 1] - bestValues[iteration - 2]; + int prevDelta2 = bestValues[iteration - 2] - bestValues[iteration - 3]; - AspirationDelta = Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16); - AspirationDelta = (AspirationDelta + 7) / 8 * 8; // Round to match grainSize + aspirationDelta = Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16); + aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize - alpha = Max(ValueByIteration[Iteration - 1] - AspirationDelta, -VALUE_INFINITE); - beta = Min(ValueByIteration[Iteration - 1] + AspirationDelta, VALUE_INFINITE); + alpha = Max(bestValues[iteration - 1] - aspirationDelta, -VALUE_INFINITE); + beta = Min(bestValues[iteration - 1] + aspirationDelta, VALUE_INFINITE); } - // Search to the current depth, rml is updated and sorted, alpha and beta could change - value = root_search(pos, ss, pv, rml, &alpha, &beta); + // Start with a small aspiration window and, in case of fail high/low, + // research with bigger window until not failing high/low anymore. + while (true) + { + // Search starting from ss+1 to allow calling update_gains() + value = search(pos, ss+1, alpha, beta, depth, 0); - // Write PV to transposition table, in case the relevant entries have - // been overwritten during the search. - insert_pv_in_tt(pos, pv); + // Write PV lines 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); - if (AbortSearch) - break; // Value cannot be trusted. Break out immediately! + // Value cannot be trusted. Break out immediately! + if (StopRequest) + break; - //Save info about search result - ValueByIteration[Iteration] = value; + assert(value >= alpha); + + // 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 * (1 << researchCountFH), VALUE_INFINITE); + researchCountFH++; + } + else if (value <= alpha) + { + AspirationFailLow = true; + StopOnPonderhit = false; + + alpha = Max(alpha - aspirationDelta * (1 << researchCountFL), -VALUE_INFINITE); + researchCountFL++; + } + else + break; + } + + // Collect info about search result + bestMove = Rml[0].pv[0]; + bestValues[iteration] = value; + bestMoveChanges[iteration] = Rml.bestMoveChanges; // Drop the easy move if differs from the new best move - if (pv[0] != EasyMove) - EasyMove = MOVE_NONE; + if (bestMove != easyMove) + easyMove = MOVE_NONE; - if (UseTimeManagement) + if (UseTimeManagement && !StopRequest) { // Time to stop? - bool stopSearch = false; - - // Stop search early if there is only a single legal move, - // we search up to Iteration 6 anyway to get a proper score. - if (Iteration >= 6 && rml.move_count() == 1) - stopSearch = true; + bool noMoreTime = false; // Stop search early when the last two iterations returned a mate score - if ( Iteration >= 6 - && abs(ValueByIteration[Iteration]) >= abs(VALUE_MATE) - 100 - && abs(ValueByIteration[Iteration-1]) >= abs(VALUE_MATE) - 100) - stopSearch = true; - - // Stop search early if one move seems to be much better than the others - if ( Iteration >= 8 - && EasyMove == pv[0] - && ( ( rml.move_nodes(0) > (pos.nodes_searched() * 85) / 100 + if ( iteration >= 6 + && abs(bestValues[iteration]) >= abs(VALUE_MATE) - 100 + && abs(bestValues[iteration-1]) >= abs(VALUE_MATE) - 100) + noMoreTime = true; + + // Stop search early if one move seems to be much better than the + // others or if there is only a single legal move. In this latter + // case we search up to Iteration 8 anyway to get a proper score. + if ( iteration >= 8 + && easyMove == bestMove + && ( Rml.size() == 1 + ||( Rml[0].nodes > (pos.nodes_searched() * 85) / 100 && current_search_time() > TimeMgr.available_time() / 16) - ||( rml.move_nodes(0) > (pos.nodes_searched() * 98) / 100 + ||( Rml[0].nodes > (pos.nodes_searched() * 98) / 100 && current_search_time() > TimeMgr.available_time() / 32))) - stopSearch = true; + noMoreTime = true; // Add some extra time if the best move has changed during the last two iterations - if (Iteration > 5 && Iteration <= 50) - TimeMgr.pv_instability(BestMoveChangesByIteration[Iteration], - BestMoveChangesByIteration[Iteration-1]); + if (iteration > 5 && iteration <= 50) + TimeMgr.pv_instability(bestMoveChanges[iteration], bestMoveChanges[iteration-1]); // Stop search if most of MaxSearchTime is consumed at the end of the // iteration. We probably don't have enough time to search the first // move at the next iteration anyway. if (current_search_time() > (TimeMgr.available_time() * 80) / 128) - stopSearch = true; + noMoreTime = true; - if (stopSearch) + if (noMoreTime) { - if (PonderSearch) + if (Pondering) StopOnPonderhit = true; else break; } } - - if (MaxDepth && Iteration >= MaxDepth) - break; - } - - // If we are pondering or in infinite search, we shouldn't print the - // best move before we are told to do so. - if (!AbortSearch && (PonderSearch || InfiniteSearch)) - wait_for_stop_or_ponderhit(); - else - // Print final search statistics - cout << "info nodes " << pos.nodes_searched() - << " nps " << nps(pos) - << " time " << current_search_time() << endl; - - // Print the best move and the ponder move to the standard output - if (pv[0] == MOVE_NONE || MultiPV > 1) - { - pv[0] = rml.move(0); - pv[1] = MOVE_NONE; } - assert(pv[0] != MOVE_NONE); - - cout << "bestmove " << pv[0]; - - if (pv[1] != MOVE_NONE) - cout << " ponder " << pv[1]; - - cout << endl; - - if (UseLogFile) - { - if (dbg_show_mean) - dbg_print_mean(LogFile); - - if (dbg_show_hit_rate) - dbg_print_hit_rate(LogFile); - - LogFile << "\nNodes: " << pos.nodes_searched() - << "\nNodes/second: " << nps(pos) - << "\nBest move: " << move_to_san(pos, pv[0]); - - StateInfo st; - pos.do_move(pv[0], st); - LogFile << "\nPonder move: " - << move_to_san(pos, pv[1]) // Works also with MOVE_NONE - << endl; - } - return rml.move_score(0); - } - - - // root_search() is the function which searches the root node. It is - // similar to search_pv except that it uses a different move ordering - // scheme, prints some information to the standard output and handles - // the fail low/high loops. - - Value root_search(Position& pos, SearchStack* ss, Move* pv, RootMoveList& rml, Value* alphaPtr, Value* betaPtr) { - - StateInfo st; - CheckInfo ci(pos); - int64_t nodes; - Move move; - Depth depth, ext, newDepth; - Value value, alpha, beta; - bool isCheck, moveIsCheck, captureOrPromotion, dangerous; - int researchCountFH, researchCountFL; - - researchCountFH = researchCountFL = 0; - alpha = *alphaPtr; - beta = *betaPtr; - isCheck = pos.is_check(); - depth = (Iteration - 2) * ONE_PLY + InitialDepth; - - // Step 1. Initialize node (polling is omitted at root) - ss->currentMove = ss->bestMove = MOVE_NONE; - - // Step 2. Check for aborted search (omitted at root) - // Step 3. Mate distance pruning (omitted at root) - // Step 4. Transposition table lookup (omitted at root) - - // Step 5. Evaluate the position statically - // At root we do this only to get reference value for child nodes - ss->evalMargin = VALUE_NONE; - ss->eval = isCheck ? VALUE_NONE : evaluate(pos, ss->evalMargin); - - // Step 6. Razoring (omitted at root) - // Step 7. Static null move pruning (omitted at root) - // Step 8. Null move search with verification search (omitted at root) - // Step 9. Internal iterative deepening (omitted at root) - - // Step extra. Fail low loop - // We start with small aspiration window and in case of fail low, we research - // with bigger window until we are not failing low anymore. - while (1) - { - // Sort the moves before to (re)search - rml.score_moves(pos); - rml.sort(); - - // Step 10. Loop through all moves in the root move list - for (int i = 0; i < rml.move_count() && !AbortSearch; i++) - { - // This is used by time management - FirstRootMove = (i == 0); - - // Save the current node count before the move is searched - nodes = pos.nodes_searched(); - - // Pick the next root move, and print the move and the move number to - // the standard output. - move = ss->currentMove = rml.move(i); - - if (current_search_time() >= 1000) - cout << "info currmove " << move - << " currmovenumber " << i + 1 << endl; - - moveIsCheck = pos.move_is_check(move); - captureOrPromotion = pos.move_is_capture_or_promotion(move); - - // Step 11. Decide the new search depth - ext = extension(pos, move, captureOrPromotion, moveIsCheck, false, false, &dangerous); - newDepth = depth + ext; - - // Step 12. Futility pruning (omitted at root) - - // Step extra. Fail high loop - // If move fails high, we research with bigger window until we are not failing - // high anymore. - value = - VALUE_INFINITE; - - while (1) - { - // Step 13. Make the move - pos.do_move(move, st, ci, moveIsCheck); - - // Step extra. pv search - // We do pv search for first moves (i < MultiPV) - // and for fail high research (value > alpha) - if (i < MultiPV || value > alpha) - { - // Aspiration window is disabled in multi-pv case - if (MultiPV > 1) - alpha = -VALUE_INFINITE; - - // Full depth PV search, done on first move or after a fail high - value = -search(pos, ss+1, -beta, -alpha, newDepth, 1); - } - else - { - // Step 14. Reduced search - // if the move fails high will be re-searched at full depth - bool doFullDepthSearch = true; - - if ( depth >= 3 * ONE_PLY - && !dangerous - && !captureOrPromotion - && !move_is_castle(move)) - { - ss->reduction = reduction(depth, i - MultiPV + 2); - if (ss->reduction) - { - assert(newDepth-ss->reduction >= ONE_PLY); - - // Reduced depth non-pv search using alpha as upperbound - value = -search(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, 1); - doFullDepthSearch = (value > alpha); - } - - // The move failed high, but if reduction is very big we could - // face a false positive, retry with a less aggressive reduction, - // if the move fails high again then go with full depth search. - if (doFullDepthSearch && ss->reduction > 2 * ONE_PLY) - { - assert(newDepth - ONE_PLY >= ONE_PLY); - - ss->reduction = ONE_PLY; - value = -search(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, 1); - doFullDepthSearch = (value > alpha); - } - ss->reduction = DEPTH_ZERO; // Restore original reduction - } - - // Step 15. Full depth search - if (doFullDepthSearch) - { - // Full depth non-pv search using alpha as upperbound - value = -search(pos, ss+1, -(alpha+1), -alpha, newDepth, 1); - - // If we are above alpha then research at same depth but as PV - // to get a correct score or eventually a fail high above beta. - if (value > alpha) - value = -search(pos, ss+1, -beta, -alpha, newDepth, 1); - } - } - - // Step 16. Undo move - pos.undo_move(move); - - // Can we exit fail high loop ? - if (AbortSearch || value < beta) - break; - - // We are failing high and going to do a research. It's important to update - // the score before research in case we run out of time while researching. - rml.set_move_score(i, value); - ss->bestMove = move; - extract_pv_from_tt(pos, move, pv); - rml.set_move_pv(i, pv); - - // Print information to the standard output - print_pv_info(pos, pv, alpha, beta, value); - - // Prepare for a research after a fail high, each time with a wider window - *betaPtr = beta = Min(beta + AspirationDelta * (1 << researchCountFH), VALUE_INFINITE); - researchCountFH++; - - } // End of fail high loop - - // Finished searching the move. If AbortSearch 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 (AbortSearch) - break; - - // Remember searched nodes counts for this move - rml.add_move_nodes(i, pos.nodes_searched() - nodes); - - assert(value >= -VALUE_INFINITE && value <= VALUE_INFINITE); - assert(value < beta); - - // Step 17. Check for new best move - if (value <= alpha && i >= MultiPV) - rml.set_move_score(i, -VALUE_INFINITE); - else - { - // PV move or new best move! - - // Update PV - rml.set_move_score(i, value); - ss->bestMove = move; - extract_pv_from_tt(pos, move, pv); - rml.set_move_pv(i, pv); - - if (MultiPV == 1) - { - // We record how often the best move has been changed in each - // iteration. This information is used for time managment: When - // the best move changes frequently, we allocate some more time. - if (i > 0) - BestMoveChangesByIteration[Iteration]++; - - // Print information to the standard output - print_pv_info(pos, pv, alpha, beta, value); - - // Raise alpha to setup proper non-pv search upper bound - if (value > alpha) - alpha = value; - } - else // MultiPV > 1 - { - rml.sort_multipv(i); - for (int j = 0; j < Min(MultiPV, rml.move_count()); j++) - { - cout << "info multipv " << j + 1 - << " score " << value_to_uci(rml.move_score(j)) - << " depth " << (j <= i ? Iteration : Iteration - 1) - << " time " << current_search_time() - << " nodes " << pos.nodes_searched() - << " nps " << nps(pos) - << " pv "; - - for (int k = 0; rml.move_pv(j, k) != MOVE_NONE && k < PLY_MAX; k++) - cout << rml.move_pv(j, k) << " "; - - cout << endl; - } - alpha = rml.move_score(Min(i, MultiPV - 1)); - } - } // PV move or new best move - - assert(alpha >= *alphaPtr); - - AspirationFailLow = (alpha == *alphaPtr); - - if (AspirationFailLow && StopOnPonderhit) - StopOnPonderhit = false; - } - - // Can we exit fail low loop ? - if (AbortSearch || !AspirationFailLow) - break; - - // Prepare for a research after a fail low, each time with a wider window - *alphaPtr = alpha = Max(alpha - AspirationDelta * (1 << researchCountFL), -VALUE_INFINITE); - researchCountFL++; - - } // Fail low loop - - // Sort the moves before to return - rml.sort(); - - return alpha; + *ponderMove = Rml[0].pv[1]; + return bestMove; } @@ -958,16 +765,17 @@ namespace { // all this work again. We also don't need to store anything to the hash table // here: This is taken care of after we return from the split point. - template + template Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) { assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE); assert(beta > alpha && beta <= VALUE_INFINITE); assert(PvNode || alpha == beta - 1); - assert(ply > 0 && ply < PLY_MAX); + assert((Root || ply > 0) && ply < PLY_MAX); assert(pos.thread() >= 0 && pos.thread() < ThreadsMgr.active_threads()); Move movesSearched[MOVES_MAX]; + int64_t nodes; StateInfo st; const TTEntry *tte; Key posKey; @@ -976,11 +784,12 @@ namespace { ValueType vt; Value bestValue, value, oldAlpha; Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific - bool isCheck, singleEvasion, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous; + bool isPvMove, isCheck, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous; bool mateThreat = false; - int moveCount = 0; + int moveCount = 0, playedMoveCount = 0; int threadID = pos.thread(); SplitPoint* sp = NULL; + refinedValue = bestValue = value = -VALUE_INFINITE; oldAlpha = alpha; isCheck = pos.is_check(); @@ -994,7 +803,8 @@ namespace { mateThreat = sp->mateThreat; goto split_point_start; } - else {} // Hack to fix icc's "statement is unreachable" warning + else if (Root) + bestValue = alpha; // Step 1. Initialize node and poll. Polling can abort search ss->currentMove = ss->bestMove = threatMove = MOVE_NONE; @@ -1007,10 +817,10 @@ namespace { } // Step 2. Check for aborted search and immediate draw - if ( AbortSearch - || ThreadsMgr.cutoff_at_splitpoint(threadID) - || pos.is_draw() - || ply >= PLY_MAX - 1) + if (( StopRequest + || ThreadsMgr.cutoff_at_splitpoint(threadID) + || pos.is_draw() + || ply >= PLY_MAX - 1) && !Root) return VALUE_DRAW; // Step 3. Mate distance pruning @@ -1020,7 +830,6 @@ namespace { return alpha; // Step 4. Transposition table lookup - // We don't want the score of a partial search to overwrite a previous full search // TT value, so we use a different position key in case of an excluded move exists. excludedMove = ss->excludedMove; @@ -1155,8 +964,8 @@ namespace { } // Step 9. Internal iterative deepening - if ( depth >= IIDDepth[PvNode] - && ttMove == MOVE_NONE + if ( depth >= IIDDepth[PvNode] + && ttMove == MOVE_NONE && (PvNode || (!isCheck && ss->eval >= beta - IIDMargin))) { Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2); @@ -1176,14 +985,12 @@ namespace { split_point_start: // At split points actual search starts from here // Initialize a MovePicker object for the current position - // FIXME currently MovePicker() c'tor is needless called also in SplitPoint - MovePicker mpBase(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta)); - MovePicker& mp = SpNode ? *sp->mp : mpBase; + MovePickerExt mp(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta)); CheckInfo ci(pos); ss->bestMove = MOVE_NONE; - singleEvasion = !SpNode && isCheck && mp.number_of_evasions() == 1; futilityBase = ss->eval + ss->evalMargin; - singularExtensionNode = !SpNode + singularExtensionNode = !Root + && !SpNode && depth >= SingularExtensionDepth[PvNode] && tte && tte->move() @@ -1212,13 +1019,37 @@ split_point_start: // At split points actual search starts from here else if (move == excludedMove) continue; else - movesSearched[moveCount++] = move; + moveCount++; + + if (Root) + { + // This is used by time management + FirstRootMove = (moveCount == 1); + + // 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 nodes " << nodes + << " nps " << nps(pos) + << " time " << current_search_time() << endl; + } + if (current_search_time() >= 1000) + cout << "info currmove " << move + << " currmovenumber " << moveCount << endl; + } + + isPvMove = (PvNode && moveCount <= (Root ? MultiPV : 1)); moveIsCheck = pos.move_is_check(move, ci); captureOrPromotion = pos.move_is_capture_or_promotion(move); // Step 11. Decide the new search depth - ext = extension(pos, move, captureOrPromotion, moveIsCheck, singleEvasion, mateThreat, &dangerous); + ext = extension(pos, move, captureOrPromotion, moveIsCheck, mateThreat, &dangerous); // Singular extension search. If all moves but one fail low on a search of (alpha-s, beta-s), // and just one fails high on (alpha, beta), then that move is singular and should be extended. @@ -1246,7 +1077,7 @@ split_point_start: // At split points actual search starts from here // Update current move (this must be done after singular extension search) ss->currentMove = move; - newDepth = depth - ONE_PLY + ext; + newDepth = depth - (!Root ? ONE_PLY : DEPTH_ZERO) + ext; // Step 12. Futility pruning (is omitted in PV nodes) if ( !PvNode @@ -1303,10 +1134,19 @@ split_point_start: // At split points actual search starts from here // Step 13. Make the move pos.do_move(move, st, ci, moveIsCheck); + if (!SpNode && !captureOrPromotion) + movesSearched[playedMoveCount++] = move; + // Step extra. pv search (only in PV nodes) // The first move in list is the expected PV - if (PvNode && moveCount == 1) + if (isPvMove) + { + // Aspiration window is disabled in multi-pv case + if (Root && MultiPV > 1) + alpha = -VALUE_INFINITE; + value = -search(pos, ss+1, -beta, -alpha, newDepth, ply+1); + } else { // Step 14. Reduced depth search @@ -1320,8 +1160,8 @@ split_point_start: // At split points actual search starts from here && ss->killers[0] != move && ss->killers[1] != move) { - ss->reduction = reduction(depth, moveCount); - + ss->reduction = Root ? reduction(depth, moveCount - MultiPV + 1) + : reduction(depth, moveCount); if (ss->reduction) { alpha = SpNode ? sp->alpha : alpha; @@ -1330,19 +1170,6 @@ split_point_start: // At split points actual search starts from here doFullDepthSearch = (value > alpha); } - - // The move failed high, but if reduction is very big we could - // face a false positive, retry with a less aggressive reduction, - // if the move fails high again then go with full depth search. - if (doFullDepthSearch && ss->reduction > 2 * ONE_PLY) - { - assert(newDepth - ONE_PLY >= ONE_PLY); - - ss->reduction = ONE_PLY; - alpha = SpNode ? sp->alpha : alpha; - value = -search(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, ply+1); - doFullDepthSearch = (value > alpha); - } ss->reduction = DEPTH_ZERO; // Restore original reduction } @@ -1355,7 +1182,7 @@ split_point_start: // At split points actual search starts from here // Step extra. pv search (only in PV nodes) // Search only for possible new PV nodes, if instead value >= beta then // parent node fails low with value <= alpha and tries another move. - if (PvNode && value > alpha && value < beta) + if (PvNode && value > alpha && (Root || value < beta)) value = -search(pos, ss+1, -beta, -alpha, newDepth, ply+1); } } @@ -1373,7 +1200,7 @@ split_point_start: // At split points actual search starts from here alpha = sp->alpha; } - if (value > bestValue && !(SpNode && ThreadsMgr.cutoff_at_splitpoint(threadID))) + if (!Root && value > bestValue && !(SpNode && ThreadsMgr.cutoff_at_splitpoint(threadID))) { bestValue = value; @@ -1402,15 +1229,67 @@ split_point_start: // At split points actual search starts from here } } + if (Root) + { + // To avoid to exit with bestValue == -VALUE_INFINITE + if (value > bestValue) + bestValue = value; + + // 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.rm->nodes += pos.nodes_searched() - nodes; + + // Step 17. Check for new best move + if (!isPvMove && value <= alpha) + mp.rm->pv_score = -VALUE_INFINITE; + else + { + // PV move or new best move! + + // Update PV + ss->bestMove = move; + mp.rm->pv_score = value; + mp.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 managment: When + // the best move changes frequently, we allocate some more time. + if (!isPvMove && MultiPV == 1) + Rml.bestMoveChanges++; + + // Inform GUI that PV has changed, in case of multi-pv UCI protocol + // requires we send all the PV lines properly sorted. + Rml.sort_multipv(moveCount); + + for (int j = 0; j < Min(MultiPV, (int)Rml.size()); j++) + cout << Rml[j].pv_info_to_uci(pos, depth, alpha, beta, j) << endl; + + // Update alpha. In multi-pv we don't use aspiration window, so + // set alpha equal to minimum score among the PV lines. + if (MultiPV > 1) + alpha = Rml[Min(moveCount, MultiPV) - 1].pv_score; // FIXME why moveCount? + else if (value > alpha) + alpha = value; + + } // PV move or new best move + } + // Step 18. Check for split - if ( !SpNode + if ( !Root + && !SpNode && depth >= ThreadsMgr.min_split_depth() && ThreadsMgr.active_threads() > 1 && bestValue < beta && ThreadsMgr.available_thread_exists(threadID) - && !AbortSearch - && !ThreadsMgr.cutoff_at_splitpoint(threadID) - && Iteration <= 99) + && !StopRequest + && !ThreadsMgr.cutoff_at_splitpoint(threadID)) ThreadsMgr.split(pos, ss, ply, &alpha, beta, &bestValue, depth, threatMove, mateThreat, moveCount, &mp, PvNode); } @@ -1425,7 +1304,7 @@ split_point_start: // At split points actual search starts from here // Step 20. Update tables // If the search is not aborted, update the transposition table, // history counters, and killer moves. - if (!SpNode && !AbortSearch && !ThreadsMgr.cutoff_at_splitpoint(threadID)) + if (!SpNode && !StopRequest && !ThreadsMgr.cutoff_at_splitpoint(threadID)) { move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove; vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER @@ -1437,8 +1316,8 @@ split_point_start: // At split points actual search starts from here if ( bestValue >= beta && !pos.move_is_capture_or_promotion(move)) { - update_history(pos, move, depth, movesSearched, moveCount); - update_killers(move, ss); + update_history(pos, move, depth, movesSearched, playedMoveCount); + update_killers(move, ss->killers); } } @@ -1542,7 +1421,7 @@ split_point_start: // At split points actual search starts from here // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will // be generated. - MovePicker mp = MovePicker(pos, ttMove, depth, H); + MovePicker mp(pos, ttMove, depth, H); CheckInfo ci(pos); // Loop through the moves until no moves remain or a beta cutoff occurs @@ -1640,6 +1519,26 @@ split_point_start: // At split points actual search starts from here } + // qsearch_scoring() scores each move of a list using a qsearch() evaluation, + // it is used in RootMoveList to get an initial scoring. + void qsearch_scoring(Position& pos, MoveStack* mlist, MoveStack* last) { + + SearchStack ss[PLY_MAX_PLUS_2]; + StateInfo st; + + memset(ss, 0, 4 * sizeof(SearchStack)); + ss[0].eval = ss[0].evalMargin = VALUE_NONE; + + for (MoveStack* cur = mlist; cur != last; cur++) + { + ss[0].currentMove = cur->move; + pos.do_move(cur->move, st); + cur->score = -qsearch(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, DEPTH_ZERO, 1); + pos.undo_move(cur->move); + } + } + + // check_is_dangerous() tests if a checking move can be pruned in qsearch(). // bestValue is updated only when returning false because in that case move // will be pruned. @@ -1800,22 +1699,19 @@ split_point_start: // At split points actual search starts from here // extended, as example because the corresponding UCI option is set to zero, // the move is marked as 'dangerous' so, at least, we avoid to prune it. template - Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, - bool singleEvasion, bool mateThreat, bool* dangerous) { + Depth extension(const Position& pos, Move m, bool captureOrPromotion, + bool moveIsCheck, bool mateThreat, bool* dangerous) { assert(m != MOVE_NONE); Depth result = DEPTH_ZERO; - *dangerous = moveIsCheck | singleEvasion | mateThreat; + *dangerous = moveIsCheck | mateThreat; if (*dangerous) { if (moveIsCheck && pos.see_sign(m) >= 0) result += CheckExtension[PvNode]; - if (singleEvasion) - result += SingleEvasionExtension[PvNode]; - if (mateThreat) result += MateThreatExtension[PvNode]; } @@ -1939,8 +1835,9 @@ split_point_start: // At split points actual search starts from here void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount) { Move m; + Value bonus = Value(int(depth) * int(depth)); - H.success(pos.piece_on(move_from(move)), move_to(move), depth); + H.update(pos.piece_on(move_from(move)), move_to(move), bonus); for (int i = 0; i < moveCount - 1; i++) { @@ -1948,8 +1845,7 @@ split_point_start: // At split points actual search starts from here assert(m != move); - if (!pos.move_is_capture_or_promotion(m)) - H.failure(pos.piece_on(move_from(m)), move_to(m), depth); + H.update(pos.piece_on(move_from(m)), move_to(m), -bonus); } } @@ -1957,13 +1853,13 @@ split_point_start: // At split points actual search starts from here // update_killers() add a good move that produced a beta-cutoff // among the killer moves of that ply. - void update_killers(Move m, SearchStack* ss) { - - if (m == ss->killers[0]) - return; + void update_killers(Move m, Move killers[]) { - ss->killers[1] = ss->killers[0]; - ss->killers[0] = m; + if (m != killers[0]) + { + killers[1] = killers[0]; + killers[0] = m; + } } @@ -1977,34 +1873,40 @@ split_point_start: // At split points actual search starts from here && after != VALUE_NONE && pos.captured_piece_type() == PIECE_TYPE_NONE && !move_is_special(m)) - H.set_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() { - - return get_system_time() - SearchStartTime; + H.update_gain(pos.piece_on(move_to(m)), move_to(m), -(before + after)); } - // value_to_uci() converts a value to a string suitable for use with the UCI protocol + // value_to_uci() converts a value to a string suitable for use with the UCI + // protocol specifications: + // + // cp The score from the engine's point of view in centipawns. + // mate Mate in y moves, not plies. If the engine is getting mated + // use negative values for y. std::string value_to_uci(Value v) { std::stringstream s; if (abs(v) < VALUE_MATE - PLY_MAX * ONE_PLY) - s << "cp " << int(v) * 100 / int(PawnValueMidgame); // Scale to pawn = 100 + s << "cp " << int(v) * 100 / int(PawnValueMidgame); // Scale to centipawns else s << "mate " << (v > 0 ? (VALUE_MATE - v + 1) / 2 : -(VALUE_MATE + v) / 2 ); return s.str(); } - // nps() computes the current nodes/second count. + + // current_search_time() returns the number of milliseconds which have passed + // since the beginning of the current search. + + int current_search_time() { + + return get_system_time() - SearchStartTime; + } + + + // nps() computes the current nodes/second count int nps(const Position& pos) { @@ -2023,7 +1925,7 @@ split_point_start: // At split points actual search starts from here int t = current_search_time(); // Poll for input - if (data_available()) + if (input_available()) { // We are line oriented, don't read single chars std::string command; @@ -2033,18 +1935,28 @@ split_point_start: // At split points actual search starts from here if (command == "quit") { - AbortSearch = true; - PonderSearch = false; - Quit = true; + // Quit the program as soon as possible + Pondering = false; + QuitRequest = StopRequest = true; return; } else if (command == "stop") { - AbortSearch = true; - PonderSearch = false; + // Stop calculating as soon as possible, but still send the "bestmove" + // and possibly the "ponder" token when finishing the search. + Pondering = false; + StopRequest = true; } else if (command == "ponderhit") - 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. + Pondering = false; + + if (StopOnPonderhit) + StopRequest = true; + } } // Print search information @@ -2066,12 +1978,12 @@ split_point_start: // At split points actual search starts from here if (dbg_show_hit_rate) dbg_print_hit_rate(); - cout << "info nodes " << pos.nodes_searched() << " nps " << nps(pos) - << " time " << t << endl; + // Send info on searched nodes as soon as we return to root + SendSearchedNodes = true; } // Should we stop the search? - if (PonderSearch) + if (Pondering) return; bool stillAtFirstMove = FirstRootMove @@ -2081,49 +1993,10 @@ split_point_start: // At split points actual search starts from here bool noMoreTime = t > TimeMgr.maximum_time() || stillAtFirstMove; - if ( (Iteration >= 3 && UseTimeManagement && noMoreTime) + if ( (UseTimeManagement && noMoreTime) || (ExactMaxTime && t >= ExactMaxTime) - || (Iteration >= 3 && MaxNodes && pos.nodes_searched() >= MaxNodes)) - AbortSearch = true; - } - - - // ponderhit() is called when the program is pondering (i.e. thinking while - // it's the opponent's turn to move) in order to let the engine know that - // it correctly predicted the opponent's move. - - void ponderhit() { - - int t = current_search_time(); - PonderSearch = false; - - bool stillAtFirstMove = FirstRootMove - && !AspirationFailLow - && t > TimeMgr.available_time(); - - bool noMoreTime = t > TimeMgr.maximum_time() - || stillAtFirstMove; - - if (Iteration >= 3 && UseTimeManagement && (noMoreTime || StopOnPonderhit)) - AbortSearch = true; - } - - - // init_ss_array() does a fast reset of the first entries of a SearchStack - // array and of all the excludedMove and skipNullMove entries. - - void init_ss_array(SearchStack* ss, int size) { - - for (int i = 0; i < size; i++, ss++) - { - ss->excludedMove = MOVE_NONE; - ss->skipNullMove = false; - ss->reduction = DEPTH_ZERO; - ss->sp = NULL; - - if (i < 3) - ss->killers[0] = ss->killers[1] = ss->mateKiller = MOVE_NONE; - } + || (MaxNodes && pos.nodes_searched() >= MaxNodes)) // FIXME + StopRequest = true; } @@ -2132,7 +2005,7 @@ split_point_start: // At split points actual search starts from here // 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 (in id_loop()). + // after which the bestmove and pondermove will be printed. void wait_for_stop_or_ponderhit() { @@ -2140,12 +2013,13 @@ split_point_start: // At split points actual search starts from here while (true) { + // Wait for a command from stdin if (!std::getline(std::cin, command)) command = "quit"; if (command == "quit") { - Quit = true; + QuitRequest = true; break; } else if (command == "ponderhit" || command == "stop") @@ -2154,88 +2028,6 @@ split_point_start: // At split points actual search starts from here } - // print_pv_info() prints to standard output and eventually to log file information on - // the current PV line. It is called at each iteration or after a new pv is found. - - void print_pv_info(const Position& pos, Move pv[], Value alpha, Value beta, Value value) { - - cout << "info depth " << Iteration - << " score " << value_to_uci(value) - << (value >= beta ? " lowerbound" : value <= alpha ? " upperbound" : "") - << " time " << current_search_time() - << " nodes " << pos.nodes_searched() - << " nps " << nps(pos) - << " pv "; - - for (Move* m = pv; *m != MOVE_NONE; m++) - cout << *m << " "; - - cout << endl; - - if (UseLogFile) - { - ValueType t = value >= beta ? VALUE_TYPE_LOWER : - value <= alpha ? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT; - - LogFile << pretty_pv(pos, current_search_time(), Iteration, value, t, pv) << endl; - } - } - - - // 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. - - void insert_pv_in_tt(const Position& pos, Move pv[]) { - - StateInfo st; - TTEntry* tte; - Position p(pos, pos.thread()); - Value v, m = VALUE_NONE; - - for (int i = 0; pv[i] != MOVE_NONE; i++) - { - tte = TT.retrieve(p.get_key()); - if (!tte || tte->move() != pv[i]) - { - v = (p.is_check() ? VALUE_NONE : evaluate(p, m)); - TT.store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, pv[i], v, m); - } - p.do_move(pv[i], st); - } - } - - - // 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 - // long PV to print that is important for position analysis. - - void extract_pv_from_tt(const Position& pos, Move bestMove, Move pv[]) { - - StateInfo st; - TTEntry* tte; - Position p(pos, pos.thread()); - int ply = 0; - - assert(bestMove != MOVE_NONE); - - pv[ply] = bestMove; - p.do_move(pv[ply++], st); - - while ( (tte = TT.retrieve(p.get_key())) != NULL - && tte->move() != MOVE_NONE - && move_is_legal(p, tte->move()) - && ply < PLY_MAX - && (!p.is_draw() || ply < 2)) - { - pv[ply] = tte->move(); - p.do_move(pv[ply++], st); - } - pv[ply] = MOVE_NONE; - } - - // init_thread() is the function which is called when a new thread is // launched. It simply calls the idle_loop() function with the supplied // threadID. There are two versions of this function; one for POSIX @@ -2343,9 +2135,9 @@ split_point_start: // At split points actual search starts from here ss->sp = tsp; if (tsp->pvNode) - search(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); + search(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); else - search(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); + search(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); assert(threads[threadID].state == THREAD_SEARCHING); @@ -2663,103 +2455,151 @@ split_point_start: // At split points actual search starts from here } - /// The RootMoveList class + /// RootMove and RootMoveList method's definitions - // RootMoveList c'tor + RootMove::RootMove() { - RootMoveList::RootMoveList(Position& pos, Move searchMoves[]) { + nodes = 0; + pv_score = non_pv_score = -VALUE_INFINITE; + pv[0] = MOVE_NONE; + } - SearchStack ss[PLY_MAX_PLUS_2]; - MoveStack mlist[MOVES_MAX]; - StateInfo st; - bool includeAllMoves = (searchMoves[0] == MOVE_NONE); + RootMove& RootMove::operator=(const RootMove& rm) { - // Initialize search stack - init_ss_array(ss, PLY_MAX_PLUS_2); - ss[0].eval = ss[0].evalMargin = VALUE_NONE; - count = 0; + const Move* src = rm.pv; + Move* dst = pv; - // Generate all legal moves - MoveStack* last = generate_moves(pos, mlist); + // Avoid a costly full rm.pv[] copy + do *dst++ = *src; while (*src++ != MOVE_NONE); - // Add each move to the moves[] array - for (MoveStack* cur = mlist; cur != last; cur++) - { - bool includeMove = includeAllMoves; + nodes = rm.nodes; + pv_score = rm.pv_score; + non_pv_score = rm.non_pv_score; + return *this; + } - for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++) - includeMove = (searchMoves[k] == cur->move); + // 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 + // long PV to print that is important for position analysis. - if (!includeMove) - continue; + void RootMove::extract_pv_from_tt(Position& pos) { - // Find a quick score for the move - moves[count].move = ss[0].currentMove = moves[count].pv[0] = cur->move; - moves[count].pv[1] = MOVE_NONE; - pos.do_move(cur->move, st); - moves[count].score = -qsearch(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, DEPTH_ZERO, 1); - pos.undo_move(cur->move); - count++; + StateInfo state[PLY_MAX_PLUS_2], *st = state; + TTEntry* tte; + int ply = 1; + + assert(pv[0] != MOVE_NONE && move_is_legal(pos, pv[0])); + + pos.do_move(pv[0], *st++); + + while ( (tte = TT.retrieve(pos.get_key())) != NULL + && tte->move() != MOVE_NONE + && move_is_legal(pos, tte->move()) + && ply < PLY_MAX + && (!pos.is_draw() || ply < 2)) + { + pv[ply] = tte->move(); + pos.do_move(pv[ply++], *st++); } - sort(); + pv[ply] = MOVE_NONE; + + do pos.undo_move(pv[--ply]); while (ply); } - // Score root moves using the standard way used in main search, the moves - // are scored according to the order in which are returned by MovePicker. + // 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. - void RootMoveList::score_moves(const Position& pos) - { - Move move; - int score = 1000; - MovePicker mp = MovePicker(pos, MOVE_NONE, ONE_PLY, H); + void RootMove::insert_pv_in_tt(Position& pos) { - while ((move = mp.get_next_move()) != MOVE_NONE) - for (int i = 0; i < count; i++) - if (moves[i].move == move) - { - moves[i].mp_score = score--; - break; - } - } + StateInfo state[PLY_MAX_PLUS_2], *st = state; + TTEntry* tte; + Key k; + Value v, m = VALUE_NONE; + int ply = 0; - // RootMoveList simple methods definitions + assert(pv[0] != MOVE_NONE && move_is_legal(pos, pv[0])); - void RootMoveList::set_move_pv(int moveNum, const Move pv[]) { + do { + k = pos.get_key(); + tte = TT.retrieve(k); - int j; + // Don't overwrite exsisting correct entries + if (!tte || tte->move() != pv[ply]) + { + v = (pos.is_check() ? VALUE_NONE : evaluate(pos, m)); + TT.store(k, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, pv[ply], v, m); + } + pos.do_move(pv[ply], *st++); - for (j = 0; pv[j] != MOVE_NONE; j++) - moves[moveNum].pv[j] = pv[j]; + } while (pv[++ply] != MOVE_NONE); - moves[moveNum].pv[j] = MOVE_NONE; + do pos.undo_move(pv[--ply]); while (ply); } + // pv_info_to_uci() returns a string with information on the current PV line + // formatted according to UCI specification and eventually writes the info + // to a log file. It is called at each iteration or after a new pv is found. + + std::string RootMove::pv_info_to_uci(Position& pos, Depth depth, Value alpha, Value beta, int pvLine) { + + std::stringstream s, l; + Move* m = pv; - // RootMoveList::sort() sorts the root move list at the beginning of a new - // iteration. + while (*m != MOVE_NONE) + l << *m++ << " "; - void RootMoveList::sort() { + s << "info depth " << depth / ONE_PLY + << " seldepth " << int(m - pv) + << " multipv " << pvLine + 1 + << " score " << value_to_uci(pv_score) + << (pv_score >= beta ? " lowerbound" : pv_score <= alpha ? " upperbound" : "") + << " time " << current_search_time() + << " nodes " << pos.nodes_searched() + << " nps " << nps(pos) + << " pv " << l.str(); - sort_multipv(count - 1); // Sort all items + if (UseLogFile && pvLine == 0) + { + ValueType t = pv_score >= beta ? VALUE_TYPE_LOWER : + pv_score <= alpha ? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT; + + LogFile << pretty_pv(pos, current_search_time(), depth / ONE_PLY, pv_score, t, pv) << endl; + } + return s.str(); } - // RootMoveList::sort_multipv() sorts the first few moves in the root move - // list by their scores and depths. It is used to order the different PVs - // correctly in MultiPV mode. + void RootMoveList::init(Position& pos, Move searchMoves[]) { + + MoveStack mlist[MOVES_MAX]; + Move* sm; - void RootMoveList::sort_multipv(int n) { + clear(); + bestMoveChanges = 0; - int i,j; + // Generate all legal moves and score them + MoveStack* last = generate(pos, mlist); + qsearch_scoring(pos, mlist, last); - for (i = 1; i <= n; i++) + // Add each move to the RootMoveList's vector + for (MoveStack* cur = mlist; cur != last; cur++) { - RootMove rm = moves[i]; - for (j = i; j > 0 && moves[j - 1] < rm; j--) - moves[j] = moves[j - 1]; + // If we have a searchMoves[] list then verify cur->move + // is in the list before to add it. + for (sm = searchMoves; *sm && *sm != cur->move; sm++) {} - moves[j] = rm; + if (searchMoves[0] && *sm != cur->move) + continue; + + RootMove rm; + rm.pv[0] = cur->move; + rm.pv[1] = MOVE_NONE; + rm.pv_score = Value(cur->score); + push_back(rm); } + sort(); } } // namespace