X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=502f12cf72cefa0ff75a38ada3be7f5e37a89787;hp=0e249705fa59a89e00d1f689d714bf33bbe024f9;hb=2e2f1064ba5bec031dbad18c34866de89cbc8276;hpb=2bb555025fc94fde3972b644bdbd27f245475213 diff --git a/src/search.cpp b/src/search.cpp index 0e249705..502f12cf 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -34,10 +34,10 @@ #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" @@ -129,7 +129,7 @@ namespace { void extract_pv_from_tt(Position& pos); void insert_pv_in_tt(Position& pos); - std::string pv_info_to_uci(const Position& pos, Value alpha, Value beta, int pvLine = 0); + std::string pv_info_to_uci(Position& pos, Value alpha, Value beta, int pvLine = 0); int64_t nodes; Value pv_score; @@ -146,10 +146,10 @@ namespace { typedef std::vector Base; RootMoveList(Position& pos, Move searchMoves[]); - void set_non_pv_scores(const Position& pos); + void set_non_pv_scores(const Position& pos, Move ttm, SearchStack* ss); void sort() { insertion_sort(begin(), end()); } - void sort_multipv(int n) { insertion_sort(begin(), begin() + n + 1); } + void sort_multipv(int n) { insertion_sort(begin(), begin() + n); } }; @@ -161,13 +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 @@ -239,6 +248,9 @@ namespace { // Book object Book OpeningBook; + // Pointer to root move list + RootMoveList* Rml; + // Iteration counter int Iteration; @@ -277,9 +289,8 @@ namespace { /// Local functions Move id_loop(Position& pos, Move searchMoves[], Move* ponderMove); - Value root_search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, RootMoveList& rml); - template + template Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply); template @@ -289,7 +300,7 @@ 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 @@ -304,7 +315,7 @@ 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); int current_search_time(); @@ -320,7 +331,54 @@ namespace { DWORD WINAPI init_thread(LPVOID threadID); #endif -} + + // A dispatcher to choose among different move sources according to the type of node + template struct MovePickerExt; + + // In Root nodes use RootMoveList Rml as source + template<> struct MovePickerExt { + + MovePickerExt(const Position&, Move, Depth, const History&, SearchStack*, Value) + : rm(Rml->begin()), firstCall(true) {} + + Move get_next_move() { + + if (!firstCall) + ++rm; + else + firstCall = false; + + return rm != Rml->end() ? rm->pv[0] : MOVE_NONE; + } + int number_of_evasions() const { return (int)Rml->size(); } + + RootMoveList::iterator rm; + bool firstCall; + }; + + // In SpNodes use split point's shared MovePicker as move source + template<> struct MovePickerExt { + + MovePickerExt(const Position&, Move, Depth, const History&, SearchStack* ss, Value) + : mp(ss->sp->mp) {} + + Move get_next_move() { return mp->get_next_move(); } + int number_of_evasions() const { return mp->number_of_evasions(); } + + RootMoveList::iterator rm; // Dummy, never used + MovePicker* mp; + }; + + // Normal 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 beta) : MovePicker(p, ttm, d, h, ss, beta) {} + + RootMoveList::iterator rm; // Dummy, never used + }; + +} // namespace //// @@ -364,15 +422,15 @@ 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. @@ -394,7 +452,7 @@ 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[], @@ -414,7 +472,7 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[ // 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()); @@ -536,7 +594,7 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[ namespace { - // id_loop() is the main iterative deepening loop. It calls root_search + // id_loop() is the main iterative deepening loop. It calls 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. @@ -547,9 +605,11 @@ namespace { Depth depth; Move EasyMove = MOVE_NONE; Value value, alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; + int researchCountFL, researchCountFH; // Moves to search are verified, scored and sorted RootMoveList rml(pos, searchMoves); + Rml = &rml; // Handle special case of searching on a mate/stale position if (rml.size() == 0) @@ -603,8 +663,50 @@ namespace { depth = (Iteration - 2) * ONE_PLY + InitialDepth; - // Search to the current depth, rml is updated and sorted - value = root_search(pos, ss, alpha, beta, depth, rml); + researchCountFL = researchCountFH = 0; + + // We start with small aspiration window and in case of fail high/low, we + // research with bigger window until we are not failing high/low anymore. + while (true) + { + // Sort the moves before to (re)search + rml.set_non_pv_scores(pos, rml[0].pv[0], ss); + rml.sort(); + + // Search to the current depth, rml is updated and sorted + value = search(pos, ss, alpha, beta, depth, 0); + + // Sort the moves before to return + rml.sort(); + + // 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 (StopRequest) + break; + + assert(value >= alpha); + + if (value >= beta) + { + // Prepare for a research after a fail high, each time with a wider window + beta = Min(beta + AspirationDelta * (1 << researchCountFH), VALUE_INFINITE); + researchCountFH++; + } + else if (value <= alpha) + { + AspirationFailLow = true; + StopOnPonderhit = false; + + // Prepare for a research after a fail low, each time with a wider window + alpha = Max(alpha - AspirationDelta * (1 << researchCountFL), -VALUE_INFINITE); + researchCountFL++; + } + else + break; + } if (StopRequest) break; // Value cannot be trusted. Break out immediately! @@ -627,7 +729,7 @@ namespace { stopSearch = true; // Stop search early when the last two iterations returned a mate score - if ( Iteration >= 6 + if ( Iteration >= 6 && abs(ValueByIteration[Iteration]) >= abs(VALUE_MATE) - 100 && abs(ValueByIteration[Iteration-1]) >= abs(VALUE_MATE) - 100) stopSearch = true; @@ -670,249 +772,6 @@ namespace { } - // root_search() is the function which searches the root node. It is - // similar to search_pv except that it prints some information to the - // standard output and handles the fail low/high loops. - - Value root_search(Position& pos, SearchStack* ss, Value alpha, - Value beta, Depth depth, RootMoveList& rml) { - StateInfo st; - CheckInfo ci(pos); - int64_t nodes; - Move move; - Depth ext, newDepth; - Value value, oldAlpha; - bool isCheck, moveIsCheck, captureOrPromotion, dangerous; - int researchCountFH, researchCountFL; - - researchCountFH = researchCountFL = 0; - oldAlpha = alpha; - isCheck = pos.is_check(); - - // 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.set_non_pv_scores(pos); - rml.sort(); - - // Step 10. Loop through all moves in the root move list - for (int i = 0; i < (int)rml.size() && !StopRequest; i++) - { - // This is used by time management - FirstRootMove = (i == 0); - - // 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; - } - - // Pick the next root move, and print the move and the move number to - // the standard output. - move = ss->currentMove = rml[i].pv[0]; - - 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); - } - 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 (StopRequest || 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. - ss->bestMove = move; - rml[i].pv_score = value; - rml[i].extract_pv_from_tt(pos); - - // Inform GUI that PV has changed - cout << rml[i].pv_info_to_uci(pos, alpha, beta) << endl; - - // Prepare for a research after a fail high, each time with a wider window - 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 (StopRequest) - break; - - // Remember searched nodes counts for this move - rml[i].nodes += 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[i].pv_score = -VALUE_INFINITE; - else - { - // PV move or new best move! - - // Update PV - ss->bestMove = move; - rml[i].pv_score = value; - rml[i].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 (MultiPV == 1 && i > 0) - BestMoveChangesByIteration[Iteration]++; - - // 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(i); - - for (int j = 0; j < Min(MultiPV, (int)rml.size()); j++) - cout << rml[j].pv_info_to_uci(pos, alpha, beta, j) << endl; - - // Update alpha. In multi-pv we don't use aspiration window - if (MultiPV == 1) - { - // Raise alpha to setup proper non-pv search upper bound - if (value > alpha) - alpha = value; - } - else // Set alpha equal to minimum score among the PV lines - alpha = rml[Min(i, MultiPV - 1)].pv_score; - - } // PV move or new best move - - assert(alpha >= oldAlpha); - - AspirationFailLow = (alpha == oldAlpha); - - if (AspirationFailLow && StopOnPonderhit) - StopOnPonderhit = false; - - } // Root moves loop - - // Can we exit fail low loop ? - if (StopRequest || !AspirationFailLow) - break; - - // Prepare for a research after a fail low, each time with a wider window - oldAlpha = alpha = Max(alpha - AspirationDelta * (1 << researchCountFL), -VALUE_INFINITE); - researchCountFL++; - - } // Fail low loop - - // Sort the moves before to return - rml.sort(); - - // 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); - - return alpha; - } - - // search<>() is the main search function for both PV and non-PV nodes and for // normal and SplitPoint nodes. When called just after a split point the search // is simpler because we have already probed the hash table, done a null move @@ -920,16 +779,17 @@ 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; @@ -938,11 +798,12 @@ 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, singleEvasion, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous; bool mateThreat = false; int moveCount = 0; int threadID = pos.thread(); SplitPoint* sp = NULL; + refinedValue = bestValue = value = -VALUE_INFINITE; oldAlpha = alpha; isCheck = pos.is_check(); @@ -962,24 +823,27 @@ namespace { ss->currentMove = ss->bestMove = threatMove = MOVE_NONE; (ss+2)->killers[0] = (ss+2)->killers[1] = (ss+2)->mateKiller = MOVE_NONE; - if (threadID == 0 && ++NodesSincePoll > NodesBetweenPolls) + if (!Root) { - NodesSincePoll = 0; - poll(pos); - } - - // Step 2. Check for aborted search and immediate draw - if ( StopRequest - || ThreadsMgr.cutoff_at_splitpoint(threadID) - || pos.is_draw() - || ply >= PLY_MAX - 1) - return VALUE_DRAW; + if (threadID == 0 && ++NodesSincePoll > NodesBetweenPolls) + { + NodesSincePoll = 0; + poll(pos); + } - // Step 3. Mate distance pruning - alpha = Max(value_mated_in(ply), alpha); - beta = Min(value_mate_in(ply+1), beta); - if (alpha >= beta) - return alpha; + // Step 2. Check for aborted search and immediate draw + if ( StopRequest + || ThreadsMgr.cutoff_at_splitpoint(threadID) + || pos.is_draw() + || ply >= PLY_MAX - 1) + return VALUE_DRAW; + + // Step 3. Mate distance pruning + alpha = Max(value_mated_in(ply), alpha); + beta = Min(value_mate_in(ply+1), beta); + if (alpha >= beta) + return alpha; + } // Step 4. Transposition table lookup @@ -1024,7 +888,8 @@ namespace { } // Save gain for the parent non-capture move - update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval); + if (!Root) + update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval); // Step 6. Razoring (is omitted in PV nodes) if ( !PvNode @@ -1117,7 +982,8 @@ namespace { } // Step 9. Internal iterative deepening - if ( depth >= IIDDepth[PvNode] + if ( !Root + && depth >= IIDDepth[PvNode] && ttMove == MOVE_NONE && (PvNode || (!isCheck && ss->eval >= beta - IIDMargin))) { @@ -1132,26 +998,28 @@ namespace { } // Expensive mate threat detection (only for PV nodes) - if (PvNode) + if (PvNode && !Root) // FIXME mateThreat = pos.has_mate_threat(); 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() && !excludedMove // Do not allow recursive singular extension search && (tte->type() & VALUE_TYPE_LOWER) && tte->depth() >= depth - 3 * ONE_PLY; + if (Root) + bestValue = alpha; + if (SpNode) { lock_grab(&(sp->lock)); @@ -1176,6 +1044,30 @@ split_point_start: // At split points actual search starts from here else movesSearched[moveCount++] = move; + 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); @@ -1208,7 +1100,7 @@ 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 @@ -1267,8 +1159,14 @@ split_point_start: // At split points actual search starts from here // 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 @@ -1282,8 +1180,8 @@ 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; @@ -1304,7 +1202,7 @@ 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); } } @@ -1322,7 +1220,7 @@ 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; @@ -1351,8 +1249,60 @@ split_point_start: // At split points actual search starts from here } } + if (Root) + { + // 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) + BestMoveChangesByIteration[Iteration]++; + + // 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, alpha, beta, j) << endl; + + // Update alpha. In multi-pv we don't use aspiration window + if (MultiPV == 1) + { + // Raise alpha to setup proper non-pv search upper bound + if (value > alpha) + alpha = bestValue = value; + } + else // Set alpha equal to minimum score among the PV lines + alpha = bestValue = (*Rml)[Min(moveCount, MultiPV) - 1].pv_score; // FIXME why moveCount? + + } // 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 @@ -1361,7 +1311,7 @@ split_point_start: // At split points actual search starts from here && !ThreadsMgr.cutoff_at_splitpoint(threadID) && Iteration <= 99) ThreadsMgr.split(pos, ss, ply, &alpha, beta, &bestValue, depth, - threatMove, mateThreat, moveCount, &mp, PvNode); + threatMove, mateThreat, moveCount, (MovePicker*)&mp, PvNode); } // Step 19. Check for mate and stalemate @@ -1387,7 +1337,7 @@ split_point_start: // At split points actual search starts from here && !pos.move_is_capture_or_promotion(move)) { update_history(pos, move, depth, movesSearched, moveCount); - update_killers(move, ss); + update_killers(move, ss->killers); } } @@ -1888,8 +1838,9 @@ 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++) { @@ -1898,7 +1849,7 @@ 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); } } @@ -1906,13 +1857,13 @@ 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) { + void update_killers(Move m, Move killers[]) { - if (m == ss->killers[0]) + if (m == killers[0]) return; - ss->killers[1] = ss->killers[0]; - ss->killers[0] = m; + killers[1] = killers[0]; + killers[0] = m; } @@ -1926,7 +1877,7 @@ 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)); + H.update_gain(pos.piece_on(move_to(m)), move_to(m), -(before + after)); } @@ -1996,7 +1947,7 @@ 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; @@ -2206,9 +2157,9 @@ 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); @@ -2613,7 +2564,7 @@ split_point_start: // At split points actual search starts from here // formatted according to UCI specification and eventually writes the info // to a log file. It is called at each iteration or after a new pv is found. - std::string RootMove::pv_info_to_uci(const Position& pos, Value alpha, Value beta, int pvLine) { + std::string RootMove::pv_info_to_uci(Position& pos, Value alpha, Value beta, int pvLine) { std::stringstream s, l; Move* m = pv; @@ -2654,7 +2605,7 @@ split_point_start: // At split points actual search starts from here ss[0].eval = ss[0].evalMargin = VALUE_NONE; // Generate all legal moves - MoveStack* last = generate_moves(pos, mlist); + MoveStack* last = generate(pos, mlist); // Add each move to the RootMoveList's vector for (MoveStack* cur = mlist; cur != last; cur++) @@ -2685,11 +2636,11 @@ split_point_start: // At split points actual search starts from here // This is the second order score that is used to compare the moves when // the first order pv scores of both moves are equal. - void RootMoveList::set_non_pv_scores(const Position& pos) + void RootMoveList::set_non_pv_scores(const Position& pos, Move ttm, SearchStack* ss) { Move move; Value score = VALUE_ZERO; - MovePicker mp(pos, MOVE_NONE, ONE_PLY, H); + MovePicker mp(pos, ttm, ONE_PLY, H, ss); while ((move = mp.get_next_move()) != MOVE_NONE) for (Base::iterator it = begin(); it != end(); ++it)