X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=d8c0c7dd3f4ad89db231456a5fe3c82c3324fc35;hp=cc49311692567ea5bcc2ef38f526863402d296e9;hb=b4a04d80385d76bb701f6727b0150889ec437723;hpb=e68ebe618c82aa2e22016d1e9474861162914002 diff --git a/src/search.cpp b/src/search.cpp index cc493116..d8c0c7dd 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008 Marco Costalba + Copyright (C) 2008-2009 Marco Costalba Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -23,6 +23,7 @@ //// #include +#include #include #include #include @@ -71,7 +72,8 @@ namespace { // Apart for the first one that has its score, following moves // normally have score -VALUE_INFINITE, so are ordered according // to the number of beta cutoffs occurred under their subtree during - // the last iteration. + // the last iteration. The counters are per thread variables to avoid + // concurrent accessing under SMP case. struct BetaCounterType { @@ -79,8 +81,6 @@ namespace { void clear(); void add(Color us, Depth d, int threadID); void read(Color us, int64_t& our, int64_t& their); - - int64_t hits[THREAD_MAX][2]; }; @@ -128,18 +128,17 @@ namespace { }; - /// Constants and variables + /// Constants and variables initialized from UCI options // Minimum number of full depth (i.e. non-reduced) moves at PV and non-PV - // nodes: - int LMRPVMoves = 15; - int LMRNonPVMoves = 4; + // nodes + int LMRPVMoves, LMRNonPVMoves; - // Depth limit for use of dynamic threat detection: - Depth ThreatDepth = 5*OnePly; + // Depth limit for use of dynamic threat detection + Depth ThreatDepth; - // Depth limit for selective search: - Depth SelectiveDepth = 7*OnePly; + // Depth limit for selective search + const Depth SelectiveDepth = 7*OnePly; // Use internal iterative deepening? const bool UseIIDAtPVNodes = true; @@ -176,33 +175,34 @@ namespace { const bool PruneBlockingMoves = false; // Use futility pruning? - bool UseQSearchFutilityPruning = true; - bool UseFutilityPruning = true; + bool UseQSearchFutilityPruning, UseFutilityPruning; // Margins for futility pruning in the quiescence search, and at frontier // and near frontier nodes - Value FutilityMarginQS = Value(0x80); - Value FutilityMargins[6] = { Value(0x100), Value(0x200), Value(0x250), - Value(0x2A0), Value(0x340), Value(0x3A0) }; + const Value FutilityMarginQS = Value(0x80); + + // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply + const Value FutilityMargins[12] = { Value(0x100), Value(0x120), Value(0x200), Value(0x220), Value(0x250), Value(0x270), + // 4 ply 4.5 ply 5 ply 5.5 ply 6 ply 6.5 ply + Value(0x2A0), Value(0x2C0), Value(0x340), Value(0x360), Value(0x3A0), Value(0x3C0) }; + // Razoring + const Depth RazorDepth = 4*OnePly; + + // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply + const Value RazorMargins[6] = { Value(0x180), Value(0x300), Value(0x300), Value(0x3C0), Value(0x3C0), Value(0x3C0) }; - // Razoring - const bool RazorAtDepthOne = false; - Depth RazorDepth = 4*OnePly; - Value RazorMargin = Value(0x300); + // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply + const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) }; // Last seconds noise filtering (LSN) - bool UseLSNFiltering = false; + bool UseLSNFiltering; bool looseOnTime = false; - int LSNTime = 4 * 1000; // In milliseconds - Value LSNValue = Value(0x200); + int LSNTime; // In milliseconds + Value LSNValue; - // Extensions. Array index 0 is used at non-PV nodes, index 1 at PV nodes. - Depth CheckExtension[2] = {OnePly, OnePly}; - Depth SingleReplyExtension[2] = {OnePly / 2, OnePly / 2}; - Depth PawnPushTo7thExtension[2] = {OnePly / 2, OnePly / 2}; - Depth PassedPawnExtension[2] = {Depth(0), Depth(0)}; - Depth PawnEndgameExtension[2] = {OnePly, OnePly}; - Depth MateThreatExtension[2] = {Depth(0), Depth(0)}; + // Extensions. Array index 0 is used at non-PV nodes, index 1 at PV nodes. + Depth CheckExtension[2], SingleReplyExtension[2], PawnPushTo7thExtension[2]; + Depth PassedPawnExtension[2], PawnEndgameExtension[2], MateThreatExtension[2]; // Search depth at iteration 1 const Depth InitialDepth = OnePly /*+ OnePly/2*/; @@ -220,7 +220,7 @@ namespace { int BestMoveChangesByIteration[PLY_MAX_PLUS_2]; // MultiPV mode - int MultiPV = 1; + int MultiPV; // Time managment variables int SearchStartTime; @@ -240,15 +240,15 @@ namespace { int ExactMaxTime; // Show current line? - bool ShowCurrentLine = false; + bool ShowCurrentLine; // Log file - bool UseLogFile = false; + bool UseLogFile; std::ofstream LogFile; // MP related variables - Depth MinimumSplitDepth = 4*OnePly; - int MaxThreadsPerSplitPoint = 4; + Depth MinimumSplitDepth; + int MaxThreadsPerSplitPoint; Thread Threads[THREAD_MAX]; Lock MPLock; bool AllThreadsShouldExit = false; @@ -281,10 +281,10 @@ namespace { bool move_is_killer(Move m, const SearchStack& ss); Depth extension(const Position &pos, Move m, bool pvNode, bool capture, bool check, bool singleReply, bool mateThreat, bool* dangerous); bool ok_to_do_nullmove(const Position &pos); - bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d); + bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d, const History& H); bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply); bool ok_to_history(const Position &pos, Move m); - void update_history(const Position& pos, Move m, Depth depth, Move movesSearched[], int moveCount); + void update_history(const Position& pos, Move m, Depth depth, History& H, Move movesSearched[], int moveCount); void update_killers(Move m, SearchStack& ss); bool fail_high_ply_1(); @@ -320,7 +320,7 @@ namespace { //// // The main transposition table -TranspositionTable TT = TranspositionTable(TTDefaultSize); +TranspositionTable TT; // Number of active threads: @@ -330,11 +330,6 @@ int ActiveThreads = 1; // but it could turn out to be useful for debugging. Lock IOLock; -History H; // Should be made local? - -// The empty search stack -SearchStack EmptySearchStack; - // SearchStack::init() initializes a search stack. Used at the beginning of a // new search from the root. @@ -358,10 +353,11 @@ void SearchStack::initKillers() { //// /// 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() +/// the program receives the UCI 'go' command. It initializes various +/// search-related global variables, and calls root_search(). It returns false +/// when a quit command is received during the search. -void think(const Position &pos, bool infinite, bool ponder, int side_to_move, +bool think(const Position &pos, bool infinite, bool ponder, int side_to_move, int time[], int increment[], int movesToGo, int maxDepth, int maxNodes, int maxTime, Move searchMoves[]) { @@ -370,15 +366,13 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move, { Move bookMove; if (get_option_value_string("Book File") != OpeningBook.file_name()) - { - OpeningBook.close(); OpeningBook.open("book.bin"); - } + bookMove = OpeningBook.get_move(pos); if (bookMove != MOVE_NONE) { std::cout << "bestmove " << bookMove << std::endl; - return; + return true; } } @@ -431,7 +425,6 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move, LMRPVMoves = get_option_value_int("Full Depth Moves (PV nodes)") + 1; LMRNonPVMoves = get_option_value_int("Full Depth Moves (non-PV nodes)") + 1; ThreatDepth = get_option_value_int("Threat Depth") * OnePly; - SelectiveDepth = get_option_value_int("Selective Plies") * OnePly; Chess960 = get_option_value_bool("UCI_Chess960"); ShowCurrentLine = get_option_value_bool("UCI_ShowCurrLine"); @@ -442,14 +435,6 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move, UseQSearchFutilityPruning = get_option_value_bool("Futility Pruning (Quiescence Search)"); UseFutilityPruning = get_option_value_bool("Futility Pruning (Main Search)"); - FutilityMarginQS = value_from_centipawns(get_option_value_int("Futility Margin (Quiescence Search)")); - int fmScale = get_option_value_int("Futility Margin Scale Factor (Main Search)"); - for (int i = 0; i < 6; i++) - FutilityMargins[i] = (FutilityMargins[i] * fmScale) / 100; - - RazorDepth = (get_option_value_int("Maximum Razoring Depth") + 1) * OnePly; - RazorMargin = value_from_centipawns(get_option_value_int("Razoring Margin")); - UseLSNFiltering = get_option_value_bool("LSN filtering"); LSNTime = get_option_value_int("LSN Time Margin (sec)") * 1000; LSNValue = value_from_centipawns(get_option_value_int("LSN Value Margin")); @@ -551,14 +536,8 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move, if (UseLogFile) LogFile.close(); - if (Quit) - { - OpeningBook.close(); - stop_threads(); - quit_eval(); - exit(0); - } Idle = true; + return !Quit; } @@ -613,10 +592,6 @@ void init_threads() { // Wait until the thread has finished launching: while (!Threads[i].running); } - - // Init also the empty search stack - EmptySearchStack.init(0); - EmptySearchStack.initKillers(); } @@ -667,7 +642,9 @@ namespace { // Initialize TT.new_search(); - H.clear(); + for (int i = 0; i < THREAD_MAX; i++) + Threads[i].H.clear(); + for (int i = 0; i < 3; i++) { ss[i].init(i); @@ -905,6 +882,10 @@ namespace { if (i < MultiPV) { + // Aspiration window is disabled in multi-pv case + if (MultiPV > 1) + alpha = -VALUE_INFINITE; + value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0); // If the value has dropped a lot compared to the last iteration, // set the boolean variable Problem to true. This variable is used @@ -1063,7 +1044,7 @@ namespace { // Transposition table lookup. At PV nodes, we don't use the TT for // pruning, but only for move ordering. - const TTEntry* tte = TT.retrieve(pos); + const TTEntry* tte = TT.retrieve(pos.get_key()); Move ttMove = (tte ? tte->move() : MOVE_NONE); // Go with internal iterative deepening if we don't have a TT move @@ -1075,7 +1056,7 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search all moves - MovePicker mp = MovePicker(pos, true, ttMove, ss[ply], depth); + MovePicker mp = MovePicker(pos, true, ttMove, depth, Threads[threadID].H, &ss[ply]); Move move, movesSearched[256]; int moveCount = 0; @@ -1196,7 +1177,7 @@ namespace { return bestValue; if (bestValue <= oldAlpha) - TT.store(pos, value_to_tt(bestValue, ply), depth, MOVE_NONE, VALUE_TYPE_UPPER); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, depth, MOVE_NONE); else if (bestValue >= beta) { @@ -1204,13 +1185,13 @@ namespace { Move m = ss[ply].pv[ply]; if (ok_to_history(pos, m)) // Only non capture moves are considered { - update_history(pos, m, depth, movesSearched, moveCount); + update_history(pos, m, depth, Threads[threadID].H, movesSearched, moveCount); update_killers(m, ss[ply]); } - TT.store(pos, value_to_tt(bestValue, ply), depth, m, VALUE_TYPE_LOWER); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, m); } else - TT.store(pos, value_to_tt(bestValue, ply), depth, ss[ply].pv[ply], VALUE_TYPE_EXACT); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, depth, ss[ply].pv[ply]); return bestValue; } @@ -1252,7 +1233,7 @@ namespace { return beta - 1; // Transposition table lookup - const TTEntry* tte = TT.retrieve(pos); + const TTEntry* tte = TT.retrieve(pos.get_key()); Move ttMove = (tte ? tte->move() : MOVE_NONE); if (tte && ok_to_use_TT(tte, depth, beta, ply)) @@ -1315,17 +1296,15 @@ namespace { } // Null move search not allowed, try razoring else if ( !value_is_mate(beta) - && approximateEval < beta - RazorMargin && depth < RazorDepth - && (RazorAtDepthOne || depth > OnePly) + && approximateEval < beta - RazorApprMargins[int(depth) - 2] + && ss[ply - 1].currentMove != MOVE_NULL && ttMove == MOVE_NONE && !pos.has_pawn_on_7th(pos.side_to_move())) { Value v = qsearch(pos, ss, beta-1, beta, Depth(0), ply, threadID); - if ( (v < beta - RazorMargin - RazorMargin / 4) - || (depth <= 2*OnePly && v < beta - RazorMargin) - || (depth <= OnePly && v < beta - RazorMargin / 2)) - return v; + if (v < beta - RazorMargins[int(depth) - 2]) + return v; } // Go with internal iterative deepening if we don't have a TT move @@ -1338,7 +1317,7 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search all moves: - MovePicker mp = MovePicker(pos, false, ttMove, ss[ply], depth); + MovePicker mp = MovePicker(pos, false, ttMove, depth, Threads[threadID].H, &ss[ply]); Move move, movesSearched[256]; int moveCount = 0; @@ -1376,16 +1355,15 @@ namespace { { // History pruning. See ok_to_prune() definition if ( moveCount >= 2 + int(depth) - && ok_to_prune(pos, move, ss[ply].threatMove, depth)) + && ok_to_prune(pos, move, ss[ply].threatMove, depth, Threads[threadID].H)) continue; // Value based pruning - if (depth < 7 * OnePly && approximateEval < beta) + if (approximateEval < beta) { if (futilityValue == VALUE_NONE) futilityValue = evaluate(pos, ei, threadID) - + FutilityMargins[int(depth)/2 - 1] - + 32 * (depth & 1); + + FutilityMargins[int(depth) - 2]; if (futilityValue < beta) { @@ -1460,17 +1438,17 @@ namespace { return bestValue; if (bestValue < beta) - TT.store(pos, value_to_tt(bestValue, ply), depth, MOVE_NONE, VALUE_TYPE_UPPER); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, depth, MOVE_NONE); else { BetaCounter.add(pos.side_to_move(), depth, threadID); Move m = ss[ply].pv[ply]; if (ok_to_history(pos, m)) // Only non capture moves are considered { - update_history(pos, m, depth, movesSearched, moveCount); + update_history(pos, m, depth, Threads[threadID].H, movesSearched, moveCount); update_killers(m, ss[ply]); } - TT.store(pos, value_to_tt(bestValue, ply), depth, m, VALUE_TYPE_LOWER); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, m); } assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1508,7 +1486,7 @@ namespace { bool pvNode = (beta - alpha != 1); if (!pvNode) { - tte = TT.retrieve(pos); + tte = TT.retrieve(pos.get_key()); if (tte && ok_to_use_TT(tte, depth, beta, ply)) { assert(tte->type() != VALUE_TYPE_EVAL); @@ -1549,7 +1527,7 @@ namespace { { // Store the score to avoid a future costly evaluation() call if (!isCheck && !tte && ei.futilityMargin == 0) - TT.store(pos, value_to_tt(bestValue, ply), Depth(-127*OnePly), MOVE_NONE, VALUE_TYPE_EVAL); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EVAL, Depth(-127*OnePly), MOVE_NONE); return bestValue; } @@ -1560,7 +1538,7 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth == 0) will be generated. - MovePicker mp = MovePicker(pos, pvNode, ttMove, EmptySearchStack, depth); + MovePicker mp = MovePicker(pos, pvNode, ttMove, depth, Threads[threadID].H); Move move; int moveCount = 0; Bitboard dcCandidates = mp.discovered_check_candidates(); @@ -1642,9 +1620,9 @@ namespace { { Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1)); if (bestValue < beta) - TT.store(pos, value_to_tt(bestValue, ply), d, MOVE_NONE, VALUE_TYPE_UPPER); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, d, MOVE_NONE); else - TT.store(pos, value_to_tt(bestValue, ply), d, m, VALUE_TYPE_LOWER); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, m); } // Update killers only for good check moves @@ -1703,7 +1681,7 @@ namespace { && !moveIsCapture && !move_promotion(move) && moveCount >= 2 + int(sp->depth) - && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth)) + && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth, Threads[threadID].H)) continue; // Make and search the move. @@ -1908,13 +1886,13 @@ namespace { void BetaCounterType::clear() { for (int i = 0; i < THREAD_MAX; i++) - hits[i][WHITE] = hits[i][BLACK] = 0ULL; + Threads[i].betaCutOffs[WHITE] = Threads[i].betaCutOffs[BLACK] = 0ULL; } void BetaCounterType::add(Color us, Depth d, int threadID) { // Weighted count based on depth - hits[threadID][us] += int(d); + Threads[threadID].betaCutOffs[us] += unsigned(d); } void BetaCounterType::read(Color us, int64_t& our, int64_t& their) { @@ -1922,8 +1900,8 @@ namespace { our = their = 0UL; for (int i = 0; i < THREAD_MAX; i++) { - our += hits[i][us]; - their += hits[i][opposite_color(us)]; + our += Threads[i].betaCutOffs[us]; + their += Threads[i].betaCutOffs[opposite_color(us)]; } } @@ -1933,7 +1911,7 @@ namespace { // Constructor RootMove::RootMove() { - nodes = cumulativeNodes = 0ULL; + nodes = cumulativeNodes = ourBeta = theirBeta = 0ULL; } // RootMove::operator<() is the comparison function used when @@ -1969,22 +1947,20 @@ namespace { for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++) includeMove = (searchMoves[k] == mlist[i].move); - if (includeMove) - { - // Find a quick score for the move - StateInfo st; - SearchStack ss[PLY_MAX_PLUS_2]; - - moves[count].move = mlist[i].move; - moves[count].nodes = 0ULL; - pos.do_move(moves[count].move, st); - moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, - Depth(0), 1, 0); - pos.undo_move(moves[count].move); - moves[count].pv[0] = moves[i].move; - moves[count].pv[1] = MOVE_NONE; // FIXME - count++; - } + if (!includeMove) + continue; + + // Find a quick score for the move + StateInfo st; + SearchStack ss[PLY_MAX_PLUS_2]; + + moves[count].move = mlist[i].move; + pos.do_move(moves[count].move, st); + moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0); + pos.undo_move(moves[count].move); + moves[count].pv[0] = moves[count].move; + moves[count].pv[1] = MOVE_NONE; // FIXME + count++; } sort(); } @@ -2313,7 +2289,7 @@ namespace { // non-tactical moves late in the move list close to the leaves are // candidates for pruning. - bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d) { + bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d, const History& H) { Square mfrom, mto, tfrom, tto; assert(move_is_ok(m)); @@ -2348,7 +2324,7 @@ namespace { return false; // Case 4: Don't prune moves with good history. - if (!H.ok_to_prune(pos.piece_on(move_from(m)), m, d)) + if (!H.ok_to_prune(pos.piece_on(mfrom), mto, d)) return false; // Case 5: If the moving piece in the threatened move is a slider, don't @@ -2392,16 +2368,16 @@ namespace { // update_history() registers a good move that produced a beta-cutoff // in history and marks as failures all the other moves of that ply. - void update_history(const Position& pos, Move m, Depth depth, + void update_history(const Position& pos, Move m, Depth depth, History& H, Move movesSearched[], int moveCount) { - H.success(pos.piece_on(move_from(m)), m, depth); + H.success(pos.piece_on(move_from(m)), move_to(m), depth); for (int i = 0; i < moveCount - 1; i++) { assert(m != movesSearched[i]); if (ok_to_history(pos, movesSearched[i])) - H.failure(pos.piece_on(move_from(movesSearched[i])), movesSearched[i]); + H.failure(pos.piece_on(move_from(movesSearched[i])), move_to(movesSearched[i])); } } @@ -2470,6 +2446,7 @@ namespace { AbortSearch = true; PonderSearch = false; Quit = true; + return; } else if(command == "stop") { @@ -2567,20 +2544,21 @@ namespace { // after which the bestmove and pondermove will be printed (in id_loop()). void wait_for_stop_or_ponderhit() { + std::string command; - while(true) { - if(!std::getline(std::cin, command)) - command = "quit"; - - if(command == "quit") { - OpeningBook.close(); - stop_threads(); - quit_eval(); - exit(0); - } - else if(command == "ponderhit" || command == "stop") - break; + while (true) + { + if (!std::getline(std::cin, command)) + command = "quit"; + + if (command == "quit") + { + Quit = true; + break; + } + else if(command == "ponderhit" || command == "stop") + break; } }