X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=a3d8781889a690e15e0b91c4044c0243245f90d1;hp=fb5d375e8e591a58a91fb0e9afe8a147846b426c;hb=189b6fc270f91f4111c1a8049c97455093f8be97;hpb=dbe5e28eaa284aeaa4927ddde8a4341200e0e601 diff --git a/src/search.cpp b/src/search.cpp index fb5d375e..a3d87818 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -21,16 +21,15 @@ #include #include #include -#include #include #include #include "book.h" #include "evaluate.h" #include "history.h" -#include "misc.h" #include "movegen.h" #include "movepick.h" +#include "notation.h" #include "search.h" #include "timeman.h" #include "thread.h" @@ -43,11 +42,11 @@ namespace Search { LimitsType Limits; std::vector RootMoves; Position RootPosition; + Time::point SearchTime; + StateStackPtr SetupStates; } using std::string; -using std::cout; -using std::endl; using Eval::evaluate; using namespace Search; @@ -56,6 +55,9 @@ namespace { // Set to true to force running with one thread. Used for debugging const bool FakeSplit = false; + // This is the minimum interval in msec between two check_time() calls + const int TimerResolution = 5; + // Different node types, used as template parameter enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV }; @@ -63,27 +65,8 @@ namespace { const bool Slidings[18] = { 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1 }; inline bool piece_is_slider(Piece p) { return Slidings[p]; } - // Maximum depth for razoring - const Depth RazorDepth = 4 * ONE_PLY; - // Dynamic razoring margin based on depth - inline Value razor_margin(Depth d) { return Value(0x200 + 0x10 * int(d)); } - - // Maximum depth for use of dynamic threat detection when null move fails low - const Depth ThreatDepth = 5 * ONE_PLY; - - // Minimum depth for use of internal iterative deepening - const Depth IIDDepth[] = { 8 * ONE_PLY, 5 * ONE_PLY }; - - // At Non-PV nodes we do an internal iterative deepening search - // when the static evaluation is bigger then beta - IIDMargin. - const Value IIDMargin = Value(0x100); - - // Minimum depth for use of singular extension - const Depth SingularExtensionDepth[] = { 8 * ONE_PLY, 6 * ONE_PLY }; - - // Futility margin for quiescence search - const Value FutilityMarginQS = Value(0x80); + inline Value razor_margin(Depth d) { return Value(512 + 16 * int(d)); } // Futility lookup tables (initialized at startup) and their access functions Value FutilityMargins[16][64]; // [depth][moveNumber] @@ -95,11 +78,6 @@ namespace { : 2 * VALUE_INFINITE; } - inline int futility_move_count(Depth d) { - - return d < 16 * ONE_PLY ? FutilityMoveCounts[d] : MAX_MOVES; - } - // Reduction lookup tables (initialized at startup) and their access function int8_t Reductions[2][64][64]; // [pv][depth][moveNumber] @@ -108,23 +86,13 @@ namespace { return (Depth) Reductions[PvNode][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)]; } - // Easy move margin. An easy move candidate must be at least this much better - // than the second best move. - const Value EasyMoveMargin = Value(0x150); - - // This is the minimum interval in msec between two check_time() calls - const int TimerResolution = 5; - - size_t MultiPV, UCIMultiPV, PVIdx; TimeManager TimeMgr; - Time SearchTime; int BestMoveChanges; int SkillLevel; bool SkillLevelEnabled, Chess960; History H; - template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth); @@ -136,56 +104,10 @@ namespace { bool connected_moves(const Position& pos, Move m1, Move m2); Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); - bool can_return_tt(const TTEntry* tte, Depth depth, Value ttValue, Value beta); bool connected_threat(const Position& pos, Move m, Move threat); Value refine_eval(const TTEntry* tte, Value ttValue, Value defaultEval); Move do_skill_level(); - string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE); - void pv_info_to_log(Position& pos, int depth, Value score, int time, Move pv[]); - void pv_info_to_uci(const Position& pos, int depth, Value alpha, Value beta); - - // MovePickerExt class template extends MovePicker and allows to choose at - // compile time the proper moves source according to the type of node. In the - // default case we simply create and use a standard MovePicker object. - template struct MovePickerExt : public MovePicker { - - MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, Stack* ss, Value b) - : MovePicker(p, ttm, d, h, ss, b) {} - }; - - // In case of a SpNode we use split point's shared MovePicker object as moves source - template<> struct MovePickerExt : public MovePicker { - - MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, Stack* ss, Value b) - : MovePicker(p, ttm, d, h, ss, b), mp(ss->sp->mp) {} - - Move next_move() { return mp->next_move(); } - MovePicker* mp; - }; - - // is_dangerous() checks whether a move belongs to some classes of known - // 'dangerous' moves so that we avoid to prune it. - FORCE_INLINE bool is_dangerous(const Position& pos, Move m, bool captureOrPromotion) { - - // Test for a pawn pushed to 7th or a passed pawn move - if (type_of(pos.piece_moved(m)) == PAWN) - { - Color c = pos.side_to_move(); - if ( relative_rank(c, to_sq(m)) == RANK_7 - || pos.pawn_is_passed(c, to_sq(m))) - return true; - } - - // Test for a capture that triggers a pawn endgame - if ( captureOrPromotion - && type_of(pos.piece_on(to_sq(m))) != PAWN - && ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) - - PieceValueMidgame[pos.piece_on(to_sq(m))] == VALUE_ZERO) - && !is_special(m)) - return true; - - return false; - } + string uci_pv(const Position& pos, int depth, Value alpha, Value beta); } // namespace @@ -220,24 +142,23 @@ void Search::init() { /// Search::perft() is our utility to verify move generation. All the leaf nodes /// up to the given depth are generated and counted and the sum returned. -int64_t Search::perft(Position& pos, Depth depth) { - - StateInfo st; - int64_t cnt = 0; - - MoveList ml(pos); +size_t Search::perft(Position& pos, Depth depth) { - // At the last ply just return the number of moves (leaf nodes) + // At the last ply just return the number of legal moves (leaf nodes) if (depth == ONE_PLY) - return ml.size(); + return MoveList(pos).size(); + StateInfo st; + size_t cnt = 0; CheckInfo ci(pos); - for ( ; !ml.end(); ++ml) + + for (MoveList ml(pos); !ml.end(); ++ml) { pos.do_move(ml.move(), st, ci, pos.move_gives_check(ml.move(), ci)); cnt += perft(pos, depth - ONE_PLY); pos.undo_move(ml.move()); } + return cnt; } @@ -248,32 +169,34 @@ int64_t Search::perft(Position& pos, Depth depth) { void Search::think() { - static Book book; // Defined static to initialize the PRNG only once + static PolyglotBook book; // Defined static to initialize the PRNG only once Position& pos = RootPosition; Chess960 = pos.is_chess960(); Eval::RootColor = pos.side_to_move(); - SearchTime.restart(); - TimeMgr.init(Limits, pos.startpos_ply_counter()); + int scaledCF = Eval::ContemptFactor * MaterialTable::game_phase(pos) / PHASE_MIDGAME; + Eval::ValueDraw[ Eval::RootColor] = VALUE_DRAW - Value(scaledCF); + Eval::ValueDraw[~Eval::RootColor] = VALUE_DRAW + Value(scaledCF); + TimeMgr.init(Limits, pos.startpos_ply_counter(), pos.side_to_move()); TT.new_search(); H.clear(); if (RootMoves.empty()) { - cout << "info depth 0 score " - << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << endl; + sync_cout << "info depth 0 score " + << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << sync_endl; RootMoves.push_back(MOVE_NONE); goto finalize; } - if (Options["OwnBook"]) + if (Options["OwnBook"] && !Limits.infinite) { Move bookMove = book.probe(pos, Options["Book File"], Options["Best Book Move"]); - if (bookMove && count(RootMoves.begin(), RootMoves.end(), bookMove)) + if (bookMove && std::count(RootMoves.begin(), RootMoves.end(), bookMove)) { - std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), bookMove)); + std::swap(RootMoves[0], *std::find(RootMoves.begin(), RootMoves.end(), bookMove)); goto finalize; } } @@ -292,40 +215,41 @@ void Search::think() { log << "\nSearching: " << pos.to_fen() << "\ninfinite: " << Limits.infinite << " ponder: " << Limits.ponder - << " time: " << Limits.time - << " increment: " << Limits.increment - << " moves to go: " << Limits.movesToGo - << endl; + << " time: " << Limits.time[pos.side_to_move()] + << " increment: " << Limits.inc[pos.side_to_move()] + << " moves to go: " << Limits.movestogo + << std::endl; } - Threads.set_size(Options["Threads"]); + Threads.wake_up(); // Set best timer interval to avoid lagging under time pressure. Timer is // used to check for remaining available thinking time. if (Limits.use_time_management()) Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution))); + else if (Limits.nodes) + Threads.set_timer(2 * TimerResolution); else Threads.set_timer(100); // We're ready to start searching. Call the iterative deepening loop function id_loop(pos); - // Stop timer and send all the slaves to sleep, if not already sleeping - Threads.set_timer(0); - Threads.set_size(1); + Threads.set_timer(0); // Stop timer + Threads.sleep(); if (Options["Use Search Log"]) { - int e = SearchTime.elapsed(); + Time::point elapsed = Time::now() - SearchTime + 1; Log log(Options["Search Log Filename"]); log << "Nodes: " << pos.nodes_searched() - << "\nNodes/second: " << (e > 0 ? pos.nodes_searched() * 1000 / e : 0) + << "\nNodes/second: " << pos.nodes_searched() * 1000 / elapsed << "\nBest move: " << move_to_san(pos, RootMoves[0].pv[0]); StateInfo st; pos.do_move(RootMoves[0].pv[0], st); - log << "\nPonder move: " << move_to_san(pos, RootMoves[0].pv[1]) << endl; + log << "\nPonder move: " << move_to_san(pos, RootMoves[0].pv[1]) << std::endl; pos.undo_move(RootMoves[0].pv[0]); } @@ -335,11 +259,11 @@ finalize: // but if we are pondering or in infinite search, we shouldn't print the best // move before we are told to do so. if (!Signals.stop && (Limits.ponder || Limits.infinite)) - Threads[pos.thread()].wait_for_stop_or_ponderhit(); + pos.this_thread()->wait_for_stop_or_ponderhit(); // Best move could be MOVE_NONE when searching on a stalemate position - cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], Chess960) - << " ponder " << move_to_uci(RootMoves[0].pv[1], Chess960) << endl; + sync_cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], Chess960) + << " ponder " << move_to_uci(RootMoves[0].pv[1], Chess960) << sync_endl; } @@ -363,7 +287,7 @@ namespace { ss->currentMove = MOVE_NULL; // Hack to skip update gains // Iterative deepening loop until requested to stop or target depth reached - while (!Signals.stop && ++depth <= MAX_PLY && (!Limits.maxDepth || depth <= Limits.maxDepth)) + while (!Signals.stop && ++depth <= MAX_PLY && (!Limits.depth || depth <= Limits.depth)) { // Save last iteration's scores before first PV line is searched and all // the move scores but the (new) PV are set to -VALUE_INFINITE. @@ -391,7 +315,8 @@ namespace { // Start with a small aspiration window and, in case of fail high/low, // research with bigger window until not failing high/low anymore. - do { + while (true) + { // Search starts from ss+1 to allow referencing (ss-1). This is // needed by update gains and ss copy when splitting at Root. bestValue = search(pos, ss+1, alpha, beta, depth * ONE_PLY); @@ -424,8 +349,8 @@ namespace { // Send full PV info to GUI if we are going to leave the loop or // if we have a fail high/low and we are deep in the search. - if ((bestValue > alpha && bestValue < beta) || SearchTime.elapsed() > 2000) - pv_info_to_uci(pos, depth, alpha, beta); + if ((bestValue > alpha && bestValue < beta) || Time::now() - SearchTime > 2000) + sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl; // In case of failing high/low increase aspiration window and // research, otherwise exit the fail high/low loop. @@ -445,9 +370,15 @@ namespace { else break; - assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE); + // Search with full window in case we have a win/mate score + if (abs(bestValue) >= VALUE_KNOWN_WIN) + { + alpha = -VALUE_INFINITE; + beta = VALUE_INFINITE; + } - } while (abs(bestValue) < VALUE_KNOWN_WIN); + assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE); + } } // Skills: Do we need to pick now the best move ? @@ -455,7 +386,11 @@ namespace { skillBest = do_skill_level(); if (!Signals.stop && Options["Use Search Log"]) - pv_info_to_log(pos, depth, bestValue, SearchTime.elapsed(), &RootMoves[0].pv[0]); + { + Log log(Options["Search Log Filename"]); + log << pretty_pv(pos, depth, bestValue, Time::now() - SearchTime, &RootMoves[0].pv[0]) + << std::endl; + } // Filter out startup noise when monitoring best move stability if (depth > 2 && BestMoveChanges) @@ -473,16 +408,16 @@ namespace { // Stop search if most of available time is already consumed. We // probably don't have enough time to search the first move at the // next iteration anyway. - if (SearchTime.elapsed() > (TimeMgr.available_time() * 62) / 100) + if (Time::now() - SearchTime > (TimeMgr.available_time() * 62) / 100) stop = true; // Stop search early if one move seems to be much better than others if ( depth >= 12 && !stop && ( (bestMoveNeverChanged && pos.captured_piece_type()) - || SearchTime.elapsed() > (TimeMgr.available_time() * 40) / 100)) + || Time::now() - SearchTime > (TimeMgr.available_time() * 40) / 100)) { - Value rBeta = bestValue - EasyMoveMargin; + Value rBeta = bestValue - 2 * PawnValueMg; (ss+1)->excludedMove = RootMoves[0].pv[0]; (ss+1)->skipNullMove = true; Value v = search(pos, ss+1, rBeta - 1, rBeta, (depth - 3) * ONE_PLY); @@ -511,7 +446,7 @@ namespace { if (skillBest == MOVE_NONE) // Still unassigned ? skillBest = do_skill_level(); - std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), skillBest)); + std::swap(RootMoves[0], *std::find(RootMoves.begin(), RootMoves.end(), skillBest)); } } @@ -531,76 +466,64 @@ namespace { const bool RootNode = (NT == Root || NT == SplitPointRoot); assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); - assert((alpha == beta - 1) || PvNode); + assert(PvNode || (alpha == beta - 1)); assert(depth > DEPTH_ZERO); - assert(pos.thread() >= 0 && pos.thread() < Threads.size()); - Move movesSearched[MAX_MOVES]; + Move movesSearched[64]; StateInfo st; const TTEntry *tte; + SplitPoint* sp; Key posKey; Move ttMove, move, excludedMove, bestMove, threatMove; Depth ext, newDepth; - Bound bt; - Value bestValue, value, oldAlpha, ttValue; - Value refinedValue, nullValue, futilityBase, futilityValue; - bool isPvMove, inCheck, singularExtensionNode, givesCheck; + Value bestValue, value, ttValue; + Value refinedValue, nullValue, futilityValue; + bool inCheck, givesCheck, pvMove, singularExtensionNode; bool captureOrPromotion, dangerous, doFullDepthSearch; - int moveCount = 0, playedMoveCount = 0; - Thread& thread = Threads[pos.thread()]; - SplitPoint* sp = NULL; + int moveCount, playedMoveCount; - refinedValue = bestValue = value = -VALUE_INFINITE; - oldAlpha = alpha; + // Step 1. Initialize node + Thread* thisThread = pos.this_thread(); + moveCount = playedMoveCount = 0; inCheck = pos.in_check(); - ss->ply = (ss-1)->ply + 1; - - // Used to send selDepth info to GUI - if (PvNode && thread.maxPly < ss->ply) - thread.maxPly = ss->ply; - // Step 1. Initialize node if (SpNode) { - tte = NULL; - ttMove = excludedMove = MOVE_NONE; - ttValue = VALUE_ZERO; sp = ss->sp; - bestMove = sp->bestMove; + bestMove = sp->bestMove; threatMove = sp->threatMove; - bestValue = sp->bestValue; - moveCount = sp->moveCount; // Lock must be held here + bestValue = sp->bestValue; + tte = NULL; + ttMove = excludedMove = MOVE_NONE; + ttValue = VALUE_NONE; - assert(bestValue > -VALUE_INFINITE && moveCount > 0); + assert(sp->bestValue > -VALUE_INFINITE && sp->moveCount > 0); goto split_point_start; } - else - { - ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; - (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; - (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; - } + bestValue = -VALUE_INFINITE; + ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; + ss->ply = (ss-1)->ply + 1; + (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; + (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; + + // Used to send selDepth info to GUI + if (PvNode && thisThread->maxPly < ss->ply) + thisThread->maxPly = ss->ply; - // Step 2. Check for aborted search and immediate draw - // Enforce node limit here. FIXME: This only works with 1 search thread. - if (Limits.maxNodes && pos.nodes_searched() >= Limits.maxNodes) - Signals.stop = true; - - if (( Signals.stop - || pos.is_draw() - || ss->ply > MAX_PLY) && !RootNode) - return VALUE_DRAW; - - // Step 3. Mate distance pruning. Even if we mate at the next move our score - // would be at best mate_in(ss->ply+1), but if alpha is already bigger because - // a shorter mate was found upward in the tree then there is no need to search - // further, we will never beat current alpha. Same logic but with reversed signs - // applies also in the opposite condition of being mated instead of giving mate, - // in this case return a fail-high score. if (!RootNode) { + // Step 2. Check for aborted search and immediate draw + if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) + return Eval::ValueDraw[pos.side_to_move()]; + + // Step 3. Mate distance pruning. Even if we mate at the next move our score + // would be at best mate_in(ss->ply+1), but if alpha is already bigger because + // a shorter mate was found upward in the tree then there is no need to search + // further, we will never beat current alpha. Same logic but with reversed signs + // applies also in the opposite condition of being mated instead of giving mate, + // in this case return a fail-high score. alpha = std::max(mated_in(ss->ply), alpha); beta = std::min(mate_in(ss->ply+1), beta); if (alpha >= beta) @@ -614,22 +537,25 @@ namespace { posKey = excludedMove ? pos.exclusion_key() : pos.key(); tte = TT.probe(posKey); ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE; - ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_ZERO; + ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; // At PV nodes we check for exact scores, while at non-PV nodes we check for // a fail high/low. Biggest advantage at probing at PV nodes is to have a // smooth experience in analysis mode. We don't probe at Root nodes otherwise // we should also update RootMoveList to avoid bogus output. - if (!RootNode && tte && (PvNode ? tte->depth() >= depth && tte->type() == BOUND_EXACT - : can_return_tt(tte, depth, ttValue, beta))) + if ( !RootNode + && tte && tte->depth() >= depth + && ( PvNode ? tte->type() == BOUND_EXACT + : ttValue >= beta ? (tte->type() & BOUND_LOWER) + : (tte->type() & BOUND_UPPER))) { TT.refresh(tte); ss->currentMove = ttMove; // Can be MOVE_NONE - if ( ttValue >= beta - && ttMove + if ( ttValue >= beta + && ttMove && !pos.is_capture_or_promotion(ttMove) - && ttMove != ss->killers[0]) + && ttMove != ss->killers[0]) { ss->killers[1] = ss->killers[0]; ss->killers[0] = ttMove; @@ -639,7 +565,7 @@ namespace { // Step 5. Evaluate the position statically and update parent's gain statistics if (inCheck) - ss->eval = ss->evalMargin = VALUE_NONE; + ss->eval = ss->evalMargin = refinedValue = VALUE_NONE; else if (tte) { assert(tte->static_value() != VALUE_NONE); @@ -656,11 +582,11 @@ namespace { // Update gain for the parent non-capture move given the static position // evaluation before and after the move. - if ( (move = (ss-1)->currentMove) != MOVE_NULL - && (ss-1)->eval != VALUE_NONE - && ss->eval != VALUE_NONE + if ( (move = (ss-1)->currentMove) != MOVE_NULL + && (ss-1)->eval != VALUE_NONE + && ss->eval != VALUE_NONE && !pos.captured_piece_type() - && !is_special(move)) + && type_of(move) == NORMAL) { Square to = to_sq(move); H.update_gain(pos.piece_on(to), to, -(ss-1)->eval - ss->eval); @@ -668,12 +594,12 @@ namespace { // Step 6. Razoring (is omitted in PV nodes) if ( !PvNode - && depth < RazorDepth + && depth < 4 * ONE_PLY && !inCheck && refinedValue + razor_margin(depth) < beta && ttMove == MOVE_NONE && abs(beta) < VALUE_MATE_IN_MAX_PLY - && !pos.has_pawn_on_7th(pos.side_to_move())) + && !pos.pawn_on_7th(pos.side_to_move())) { Value rbeta = beta - razor_margin(depth); Value v = qsearch(pos, ss, rbeta-1, rbeta, DEPTH_ZERO); @@ -688,12 +614,12 @@ namespace { // the score by more than futility_margin(depth) if we do a null move. if ( !PvNode && !ss->skipNullMove - && depth < RazorDepth + && depth < 4 * ONE_PLY && !inCheck - && refinedValue - futility_margin(depth, 0) >= beta + && refinedValue - FutilityMargins[depth][0] >= beta && abs(beta) < VALUE_MATE_IN_MAX_PLY && pos.non_pawn_material(pos.side_to_move())) - return refinedValue - futility_margin(depth, 0); + return refinedValue - FutilityMargins[depth][0]; // Step 8. Null move search with verification search (is omitted in PV nodes) if ( !PvNode @@ -707,16 +633,16 @@ namespace { ss->currentMove = MOVE_NULL; // Null move dynamic reduction based on depth - int R = 3 + (depth >= 5 * ONE_PLY ? depth / 8 : 0); + Depth R = 3 * ONE_PLY + depth / 4; // Null move dynamic reduction based on value - if (refinedValue - PawnValueMidgame > beta) - R++; + if (refinedValue - PawnValueMg > beta) + R += ONE_PLY; pos.do_null_move(st); (ss+1)->skipNullMove = true; - nullValue = depth-R*ONE_PLY < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) - : - search(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY); + nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) + : - search(pos, ss+1, -beta, -alpha, depth-R); (ss+1)->skipNullMove = false; pos.do_null_move(st); @@ -731,7 +657,7 @@ namespace { // Do verification search at high depths ss->skipNullMove = true; - Value v = search(pos, ss, alpha, beta, depth-R*ONE_PLY); + Value v = search(pos, ss, alpha, beta, depth-R); ss->skipNullMove = false; if (v >= beta) @@ -747,7 +673,7 @@ namespace { // parent node, which will trigger a re-search with full depth). threatMove = (ss+1)->currentMove; - if ( depth < ThreatDepth + if ( depth < 5 * ONE_PLY && (ss-1)->reduction && threatMove != MOVE_NONE && connected_moves(pos, (ss-1)->currentMove, threatMove)) @@ -760,7 +686,7 @@ namespace { // and a reduced search returns a value much above beta, we can (almost) safely // prune the previous move. if ( !PvNode - && depth >= RazorDepth + ONE_PLY + && depth >= 5 * ONE_PLY && !inCheck && !ss->skipNullMove && excludedMove == MOVE_NONE @@ -776,7 +702,7 @@ namespace { MovePicker mp(pos, ttMove, H, pos.captured_piece_type()); CheckInfo ci(pos); - while ((move = mp.next_move()) != MOVE_NONE) + while ((move = mp.next_move()) != MOVE_NONE) if (pos.pl_move_is_legal(move, ci.pinned)) { ss->currentMove = move; @@ -789,9 +715,9 @@ namespace { } // Step 10. Internal iterative deepening - if ( depth >= IIDDepth[PvNode] + if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY) && ttMove == MOVE_NONE - && (PvNode || (!inCheck && ss->eval + IIDMargin >= beta))) + && (PvNode || (!inCheck && ss->eval + Value(256) >= beta))) { Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2); @@ -805,23 +731,20 @@ namespace { split_point_start: // At split points actual search starts from here - MovePickerExt mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); + MovePicker mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); CheckInfo ci(pos); - futilityBase = ss->eval + ss->evalMargin; + value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc singularExtensionNode = !RootNode && !SpNode - && depth >= SingularExtensionDepth[PvNode] - && ttMove != MOVE_NONE + && depth >= (PvNode ? 6 * ONE_PLY : 8 * ONE_PLY) + && ttMove != MOVE_NONE && !excludedMove // Recursive singular search is not allowed && (tte->type() & BOUND_LOWER) - && tte->depth() >= depth - 3 * ONE_PLY; + && tte->depth() >= depth - 3 * ONE_PLY; // Step 11. Loop through moves // Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs - while ( bestValue < beta - && (move = mp.next_move()) != MOVE_NONE - && !thread.cutoff_occurred() - && !Signals.stop) + while ((move = mp.next_move()) != MOVE_NONE) { assert(is_ok(move)); @@ -831,17 +754,17 @@ split_point_start: // At split points actual search starts from here // At root obey the "searchmoves" option and skip moves not listed in Root // Move List, as a consequence any illegal move is also skipped. In MultiPV // mode we also skip PV moves which have been already searched. - if (RootNode && !count(RootMoves.begin() + PVIdx, RootMoves.end(), move)) - continue; - - // At PV and SpNode nodes we want all moves to be legal since the beginning - if ((PvNode || SpNode) && !pos.pl_move_is_legal(move, ci.pinned)) + if (RootNode && !std::count(RootMoves.begin() + PVIdx, RootMoves.end(), move)) continue; if (SpNode) { + // Shared counter cannot be decremented later if move turns out to be illegal + if (!pos.pl_move_is_legal(move, ci.pinned)) + continue; + moveCount = ++sp->moveCount; - lock_release(sp->lock); + sp->mutex.unlock(); } else moveCount++; @@ -850,46 +773,51 @@ split_point_start: // At split points actual search starts from here { Signals.firstRootMove = (moveCount == 1); - if (pos.thread() == 0 && SearchTime.elapsed() > 2000) - cout << "info depth " << depth / ONE_PLY - << " currmove " << move_to_uci(move, Chess960) - << " currmovenumber " << moveCount + PVIdx << endl; + if (thisThread == Threads.main_thread() && Time::now() - SearchTime > 2000) + sync_cout << "info depth " << depth / ONE_PLY + << " currmove " << move_to_uci(move, Chess960) + << " currmovenumber " << moveCount + PVIdx << sync_endl; } - isPvMove = (PvNode && moveCount <= 1); + ext = DEPTH_ZERO; captureOrPromotion = pos.is_capture_or_promotion(move); givesCheck = pos.move_gives_check(move, ci); - dangerous = givesCheck || is_dangerous(pos, move, captureOrPromotion); - ext = DEPTH_ZERO; + dangerous = givesCheck + || pos.is_passed_pawn_push(move) + || type_of(move) == CASTLE + || ( captureOrPromotion // Entering a pawn endgame? + && type_of(pos.piece_on(to_sq(move))) != PAWN + && type_of(move) == NORMAL + && ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) + - PieceValue[Mg][pos.piece_on(to_sq(move))] == VALUE_ZERO)); // Step 12. Extend checks and, in PV nodes, also dangerous moves if (PvNode && dangerous) ext = ONE_PLY; else if (givesCheck && pos.see_sign(move) >= 0) - ext = PvNode ? ONE_PLY : ONE_PLY / 2; + ext = ONE_PLY / 2; // 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. To verify this we do a reduced search // on all the other moves but the ttMove, if result is lower than ttValue minus // a margin then we extend ttMove. - if ( singularExtensionNode + if ( singularExtensionNode && !ext - && move == ttMove - && pos.pl_move_is_legal(move, ci.pinned)) + && move == ttMove + && pos.pl_move_is_legal(move, ci.pinned) + && abs(ttValue) < VALUE_KNOWN_WIN) { - if (abs(ttValue) < VALUE_KNOWN_WIN) - { - Value rBeta = ttValue - int(depth); - ss->excludedMove = move; - ss->skipNullMove = true; - value = search(pos, ss, rBeta - 1, rBeta, depth / 2); - ss->skipNullMove = false; - ss->excludedMove = MOVE_NONE; - if (value < rBeta) - ext = ONE_PLY; - } + Value rBeta = ttValue - int(depth); + ss->excludedMove = move; + ss->skipNullMove = true; + value = search(pos, ss, rBeta - 1, rBeta, depth / 2); + ss->skipNullMove = false; + ss->excludedMove = MOVE_NONE; + + if (value < rBeta) + ext = rBeta >= beta ? ONE_PLY + ONE_PLY / 2 : ONE_PLY; } // Update current move (this must be done after singular extension search) @@ -901,15 +829,16 @@ split_point_start: // At split points actual search starts from here && !inCheck && !dangerous && move != ttMove - && !is_castle(move) - && (bestValue > VALUE_MATED_IN_MAX_PLY || bestValue == -VALUE_INFINITE)) + && (bestValue > VALUE_MATED_IN_MAX_PLY || ( bestValue == -VALUE_INFINITE + && alpha > VALUE_MATED_IN_MAX_PLY))) { // Move count based pruning - if ( moveCount >= futility_move_count(depth) + if ( depth < 16 * ONE_PLY + && moveCount >= FutilityMoveCounts[depth] && (!threatMove || !connected_threat(pos, move, threatMove))) { if (SpNode) - lock_grab(sp->lock); + sp->mutex.lock(); continue; } @@ -918,13 +847,13 @@ split_point_start: // At split points actual search starts from here // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth, // but fixing this made program slightly weaker. Depth predictedDepth = newDepth - reduction(depth, moveCount); - futilityValue = futilityBase + futility_margin(predictedDepth, moveCount) + futilityValue = ss->eval + ss->evalMargin + futility_margin(predictedDepth, moveCount) + H.gain(pos.piece_moved(move), to_sq(move)); if (futilityValue < beta) { if (SpNode) - lock_grab(sp->lock); + sp->mutex.lock(); continue; } @@ -934,7 +863,7 @@ split_point_start: // At split points actual search starts from here && pos.see_sign(move) < 0) { if (SpNode) - lock_grab(sp->lock); + sp->mutex.lock(); continue; } @@ -947,8 +876,9 @@ split_point_start: // At split points actual search starts from here continue; } + pvMove = PvNode ? moveCount == 1 : false; ss->currentMove = move; - if (!SpNode && !captureOrPromotion) + if (!SpNode && !captureOrPromotion && playedMoveCount < 64) movesSearched[playedMoveCount++] = move; // Step 14. Make the move @@ -956,11 +886,10 @@ split_point_start: // At split points actual search starts from here // Step 15. Reduced depth search (LMR). If the move fails high will be // re-searched at full depth. - if ( depth > 3 * ONE_PLY - && !isPvMove + if ( depth > 3 * ONE_PLY + && !pvMove && !captureOrPromotion && !dangerous - && !is_castle(move) && ss->killers[0] != move && ss->killers[1] != move) { @@ -974,7 +903,7 @@ split_point_start: // At split points actual search starts from here ss->reduction = DEPTH_ZERO; } else - doFullDepthSearch = !isPvMove; + doFullDepthSearch = !pvMove; // Step 16. Full depth search, when LMR is skipped or fails high if (doFullDepthSearch) @@ -987,7 +916,7 @@ split_point_start: // At split points actual search starts from here // Only for PV nodes do a full PV search on the first move or after a fail // high, in the latter case search only if value < beta, otherwise let the // parent node to fail low with value <= alpha and to try another move. - if (PvNode && (isPvMove || (value > alpha && (RootNode || value < beta)))) + if (PvNode && (pvMove || (value > alpha && (RootNode || value < beta)))) value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) : - search(pos, ss+1, -beta, -alpha, newDepth); @@ -999,7 +928,7 @@ split_point_start: // At split points actual search starts from here // Step 18. Check for new best move if (SpNode) { - lock_grab(sp->lock); + sp->mutex.lock(); bestValue = sp->bestValue; alpha = sp->alpha; } @@ -1008,12 +937,15 @@ split_point_start: // At split points actual search starts from here // was aborted because the user interrupted the search or because we // ran out of time. In this case, the return value of the search cannot // be trusted, and we don't update the best move and/or PV. - if (RootNode && !Signals.stop) + if (Signals.stop || thisThread->cutoff_occurred()) + return bestValue; + + if (RootNode) { - RootMove& rm = *find(RootMoves.begin(), RootMoves.end(), move); + RootMove& rm = *std::find(RootMoves.begin(), RootMoves.end(), move); // PV move or new best move ? - if (isPvMove || value > alpha) + if (pvMove || value > alpha) { rm.score = value; rm.extract_pv_from_tt(pos); @@ -1021,7 +953,7 @@ split_point_start: // At split points actual search starts from here // We record how often the best move has been changed in each // iteration. This information is used for time management: When // the best move changes frequently, we allocate some more time. - if (!isPvMove && MultiPV == 1) + if (!pvMove && MultiPV == 1) BestMoveChanges++; } else @@ -1029,82 +961,80 @@ split_point_start: // At split points actual search starts from here // is not a problem when sorting becuase sort is stable and move // position in the list is preserved, just the PV is pushed up. rm.score = -VALUE_INFINITE; - } if (value > bestValue) { bestValue = value; - bestMove = move; - - if ( PvNode - && value > alpha - && value < beta) // We want always alpha < beta - alpha = value; + if (SpNode) sp->bestValue = value; - if (SpNode && !thread.cutoff_occurred()) + if (value > alpha) { - sp->bestValue = value; - sp->bestMove = move; - sp->alpha = alpha; - - if (value >= beta) - sp->cutoff = true; + bestMove = move; + if (SpNode) sp->bestMove = move; + + if (PvNode && value < beta) + { + alpha = value; // Update alpha here! Always alpha < beta + if (SpNode) sp->alpha = value; + } + else // Fail high + { + if (SpNode) sp->cutoff = true; + break; + } } } - // Step 19. Check for split + // Step 19. Check for splitting the search if ( !SpNode - && depth >= Threads.min_split_depth() - && bestValue < beta - && Threads.available_slave_exists(pos.thread()) - && !Signals.stop - && !thread.cutoff_occurred()) + && depth >= Threads.min_split_depth() + && bestValue < beta + && Threads.available_slave_exists(thisThread)) + { bestValue = Threads.split(pos, ss, alpha, beta, bestValue, &bestMove, - depth, threatMove, moveCount, &mp, NT); + depth, threatMove, moveCount, mp, NT); + break; + } } + if (SpNode) + return bestValue; + // Step 20. Check for mate and stalemate // All legal moves have been searched and if there are no legal moves, it // must be mate or stalemate. Note that we can have a false positive in // case of Signals.stop or thread.cutoff_occurred() are set, but this is // harmless because return value is discarded anyhow in the parent nodes. // If we are in a singular extension search then return a fail low score. + // A split node has at least one move, the one tried before to be splitted. if (!moveCount) - return excludedMove ? oldAlpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW; + return excludedMove ? alpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW; // If we have pruned all the moves without searching return a fail-low score if (bestValue == -VALUE_INFINITE) { assert(!playedMoveCount); - bestValue = oldAlpha; + bestValue = alpha; } - // Step 21. Update tables - // Update transposition table entry, killers and history - if (!SpNode && !Signals.stop && !thread.cutoff_occurred()) + if (bestValue >= beta) // Failed high { - move = bestValue <= oldAlpha ? MOVE_NONE : bestMove; - bt = bestValue <= oldAlpha ? BOUND_UPPER - : bestValue >= beta ? BOUND_LOWER : BOUND_EXACT; + TT.store(posKey, value_to_tt(bestValue, ss->ply), BOUND_LOWER, depth, + bestMove, ss->eval, ss->evalMargin); - TT.store(posKey, value_to_tt(bestValue, ss->ply), bt, depth, move, ss->eval, ss->evalMargin); - - // Update killers and history for non capture cut-off moves - if ( bestValue >= beta - && !pos.is_capture_or_promotion(move) - && !inCheck) + if (!pos.is_capture_or_promotion(bestMove) && !inCheck) { - if (move != ss->killers[0]) + if (bestMove != ss->killers[0]) { ss->killers[1] = ss->killers[0]; - ss->killers[0] = move; + ss->killers[0] = bestMove; } // Increase history value of the cut-off move Value bonus = Value(int(depth) * int(depth)); - H.add(pos.piece_moved(move), to_sq(move), bonus); + H.add(pos.piece_moved(bestMove), to_sq(bestMove), bonus); // Decrease history of all the other played non-capture moves for (int i = 0; i < playedMoveCount - 1; i++) @@ -1114,6 +1044,10 @@ split_point_start: // At split points actual search starts from here } } } + else // Failed low or PV search + TT.store(posKey, value_to_tt(bestValue, ss->ply), + PvNode && bestMove != MOVE_NONE ? BOUND_EXACT : BOUND_UPPER, + depth, bestMove, ss->eval, ss->evalMargin); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1132,39 +1066,41 @@ split_point_start: // At split points actual search starts from here assert(NT == PV || NT == NonPV); assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); - assert((alpha == beta - 1) || PvNode); + assert(PvNode || (alpha == beta - 1)); assert(depth <= DEPTH_ZERO); - assert(pos.thread() >= 0 && pos.thread() < Threads.size()); StateInfo st; - Move ttMove, move, bestMove; - Value ttValue, bestValue, value, evalMargin, futilityValue, futilityBase; - bool inCheck, enoughMaterial, givesCheck, evasionPrunable; const TTEntry* tte; + Key posKey; + Move ttMove, move, bestMove; + Value bestValue, value, ttValue, futilityValue, futilityBase; + bool inCheck, givesCheck, enoughMaterial, evasionPrunable; Depth ttDepth; - Bound bt; - Value oldAlpha = alpha; + inCheck = pos.in_check(); ss->currentMove = bestMove = MOVE_NONE; ss->ply = (ss-1)->ply + 1; // Check for an instant draw or maximum ply reached if (pos.is_draw() || ss->ply > MAX_PLY) - return VALUE_DRAW; + return Eval::ValueDraw[pos.side_to_move()]; + + // Transposition table lookup. At PV nodes, we don't use the TT for + // pruning, but only for move ordering. + posKey = pos.key(); + tte = TT.probe(posKey); + ttMove = tte ? tte->move() : MOVE_NONE; + ttValue = tte ? value_from_tt(tte->value(),ss->ply) : VALUE_NONE; // Decide whether or not to include checks, this fixes also the type of // TT entry depth that we are going to use. Note that in qsearch we use // only two types of depth in TT: DEPTH_QS_CHECKS or DEPTH_QS_NO_CHECKS. - inCheck = pos.in_check(); - ttDepth = (inCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS : DEPTH_QS_NO_CHECKS); - - // Transposition table lookup. At PV nodes, we don't use the TT for - // pruning, but only for move ordering. - tte = TT.probe(pos.key()); - ttMove = (tte ? tte->move() : MOVE_NONE); - ttValue = tte ? value_from_tt(tte->value(),ss->ply) : VALUE_ZERO; + ttDepth = inCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS : DEPTH_QS_NO_CHECKS; - if (!PvNode && tte && can_return_tt(tte, ttDepth, ttValue, beta)) + if ( tte && tte->depth() >= ttDepth + && ( PvNode ? tte->type() == BOUND_EXACT + : ttValue >= beta ? (tte->type() & BOUND_LOWER) + : (tte->type() & BOUND_UPPER))) { ss->currentMove = ttMove; // Can be MOVE_NONE return ttValue; @@ -1173,8 +1109,8 @@ split_point_start: // At split points actual search starts from here // Evaluate the position statically if (inCheck) { + ss->eval = ss->evalMargin = VALUE_NONE; bestValue = futilityBase = -VALUE_INFINITE; - ss->eval = evalMargin = VALUE_NONE; enoughMaterial = false; } else @@ -1183,17 +1119,17 @@ split_point_start: // At split points actual search starts from here { assert(tte->static_value() != VALUE_NONE); - evalMargin = tte->static_value_margin(); ss->eval = bestValue = tte->static_value(); + ss->evalMargin = tte->static_value_margin(); } else - ss->eval = bestValue = evaluate(pos, evalMargin); + ss->eval = bestValue = evaluate(pos, ss->evalMargin); // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) { if (!tte) - TT.store(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin); + TT.store(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, ss->evalMargin); return bestValue; } @@ -1201,8 +1137,8 @@ split_point_start: // At split points actual search starts from here if (PvNode && bestValue > alpha) alpha = bestValue; - futilityBase = ss->eval + evalMargin + FutilityMarginQS; - enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame; + futilityBase = ss->eval + ss->evalMargin + Value(128); + enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMg; } // Initialize a MovePicker object for the current position, and prepare @@ -1213,8 +1149,7 @@ split_point_start: // At split points actual search starts from here CheckInfo ci(pos); // Loop through the moves until no moves remain or a beta cutoff occurs - while ( bestValue < beta - && (move = mp.next_move()) != MOVE_NONE) + while ((move = mp.next_move()) != MOVE_NONE) { assert(is_ok(move)); @@ -1226,12 +1161,12 @@ split_point_start: // At split points actual search starts from here && !givesCheck && move != ttMove && enoughMaterial - && !is_promotion(move) + && type_of(move) != PROMOTION && !pos.is_passed_pawn_push(move)) { futilityValue = futilityBase - + PieceValueEndgame[pos.piece_on(to_sq(move))] - + (is_enpassant(move) ? PawnValueEndgame : VALUE_ZERO); + + PieceValue[Eg][pos.piece_on(to_sq(move))] + + (type_of(move) == ENPASSANT ? PawnValueEg : VALUE_ZERO); if (futilityValue < beta) { @@ -1250,8 +1185,8 @@ split_point_start: // At split points actual search starts from here // Detect non-capture evasions that are candidate to be pruned evasionPrunable = !PvNode - && inCheck - && bestValue > VALUE_MATED_IN_MAX_PLY + && inCheck + && bestValue > VALUE_MATED_IN_MAX_PLY && !pos.is_capture(move) && !pos.can_castle(pos.side_to_move()); @@ -1259,7 +1194,7 @@ split_point_start: // At split points actual search starts from here if ( !PvNode && (!inCheck || evasionPrunable) && move != ttMove - && !is_promotion(move) + && type_of(move) != PROMOTION && pos.see_sign(move) < 0) continue; @@ -1269,7 +1204,7 @@ split_point_start: // At split points actual search starts from here && givesCheck && move != ttMove && !pos.is_capture_or_promotion(move) - && ss->eval + PawnValueMidgame / 4 < beta + && ss->eval + PawnValueMg / 4 < beta && !check_is_dangerous(pos, move, futilityBase, beta)) continue; @@ -1281,21 +1216,31 @@ split_point_start: // At split points actual search starts from here // Make and search the move pos.do_move(move, st, ci, givesCheck); - value = -qsearch(pos, ss+1, -beta, -alpha, depth-ONE_PLY); + value = -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY); pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); - // New best move? + // Check for new best move if (value > bestValue) { bestValue = value; - bestMove = move; - if ( PvNode - && value > alpha - && value < beta) // We want always alpha < beta - alpha = value; + if (value > alpha) + { + if (PvNode && value < beta) // Update alpha here! Always alpha < beta + { + alpha = value; + bestMove = move; + } + else // Fail high + { + TT.store(posKey, value_to_tt(value, ss->ply), BOUND_LOWER, + ttDepth, move, ss->eval, ss->evalMargin); + + return value; + } + } } } @@ -1304,12 +1249,9 @@ split_point_start: // At split points actual search starts from here if (inCheck && bestValue == -VALUE_INFINITE) return mated_in(ss->ply); // Plies to mate from the root - // Update transposition table - move = bestValue <= oldAlpha ? MOVE_NONE : bestMove; - bt = bestValue <= oldAlpha ? BOUND_UPPER - : bestValue >= beta ? BOUND_LOWER : BOUND_EXACT; - - TT.store(pos.key(), value_to_tt(bestValue, ss->ply), bt, ttDepth, move, ss->eval, evalMargin); + TT.store(posKey, value_to_tt(bestValue, ss->ply), + PvNode && bestMove != MOVE_NONE ? BOUND_EXACT : BOUND_UPPER, + ttDepth, bestMove, ss->eval, ss->evalMargin); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1342,7 +1284,7 @@ split_point_start: // At split points actual search starts from here // Rule 1. Checks which give opponent's king at most one escape square are dangerous b = kingAtt & ~pos.pieces(them) & ~newAtt & ~(1ULL << to); - if (single_bit(b)) // Catches also !b + if (!more_than_one(b)) return true; // Rule 2. Queen contact check is very dangerous @@ -1354,7 +1296,7 @@ split_point_start: // At split points actual search starts from here while (b) { // Note that here we generate illegal "double move"! - if (futilityBase + PieceValueEndgame[pos.piece_on(pop_1st_bit(&b))] >= beta) + if (futilityBase + PieceValue[Eg][pos.piece_on(pop_lsb(&b))] >= beta) return true; } @@ -1391,7 +1333,7 @@ split_point_start: // At split points actual search starts from here // Case 3: Moving through the vacated square p2 = pos.piece_on(f2); - if (piece_is_slider(p2) && (squares_between(f2, t2) & f1)) + if (piece_is_slider(p2) && (between_bb(f2, t2) & f1)) return true; // Case 4: The destination square for m2 is defended by the moving piece in m1 @@ -1402,7 +1344,7 @@ split_point_start: // At split points actual search starts from here // Case 5: Discovered check, checking piece is the piece moved in m1 ksq = pos.king_square(pos.side_to_move()); if ( piece_is_slider(p1) - && (squares_between(t1, ksq) & f2) + && (between_bb(t1, ksq) & f2) && (pos.attacks_from(p1, t1, pos.pieces() ^ f2) & ksq)) return true; @@ -1466,7 +1408,7 @@ split_point_start: // At split points actual search starts from here // Case 2: If the threatened piece has value less than or equal to the // value of the threatening piece, don't prune moves which defend it. if ( pos.is_capture(threat) - && ( PieceValueMidgame[pos.piece_on(tfrom)] >= PieceValueMidgame[pos.piece_on(tto)] + && ( PieceValue[Mg][pos.piece_on(tfrom)] >= PieceValue[Mg][pos.piece_on(tto)] || type_of(pos.piece_on(tfrom)) == KING) && pos.move_attacks_square(m, tto)) return true; @@ -1474,7 +1416,7 @@ split_point_start: // At split points actual search starts from here // Case 3: If the moving piece in the threatened move is a slider, don't // prune safe moves which block its ray. if ( piece_is_slider(pos.piece_on(tfrom)) - && (squares_between(tfrom, tto) & mto) + && (between_bb(tfrom, tto) & mto) && pos.see_sign(m) >= 0) return true; @@ -1482,20 +1424,6 @@ split_point_start: // At split points actual search starts from here } - // can_return_tt() returns true if a transposition table score can be used to - // cut-off at a given point in search. - - bool can_return_tt(const TTEntry* tte, Depth depth, Value v, Value beta) { - - return ( tte->depth() >= depth - || v >= std::max(VALUE_MATE_IN_MAX_PLY, beta) - || v < std::min(VALUE_MATED_IN_MAX_PLY, beta)) - - && ( ((tte->type() & BOUND_LOWER) && v >= beta) - || ((tte->type() & BOUND_UPPER) && v < beta)); - } - - // refine_eval() returns the transposition table score if possible, otherwise // falls back on static position evaluation. @@ -1511,156 +1439,6 @@ split_point_start: // At split points actual search starts from here } - // score_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. - - string score_to_uci(Value v, Value alpha, Value beta) { - - std::stringstream s; - - if (abs(v) < VALUE_MATE_IN_MAX_PLY) - s << "cp " << v * 100 / int(PawnValueMidgame); - else - s << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2; - - s << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : ""); - - return s.str(); - } - - - // pv_info_to_uci() sends search info to GUI. UCI protocol requires to send all - // the PV lines also if are still to be searched and so refer to the previous - // search score. - - void pv_info_to_uci(const Position& pos, int depth, Value alpha, Value beta) { - - int t = SearchTime.elapsed(); - int selDepth = 0; - - for (int i = 0; i < Threads.size(); i++) - if (Threads[i].maxPly > selDepth) - selDepth = Threads[i].maxPly; - - for (size_t i = 0; i < std::min(UCIMultiPV, RootMoves.size()); i++) - { - bool updated = (i <= PVIdx); - - if (depth == 1 && !updated) - continue; - - int d = (updated ? depth : depth - 1); - Value v = (updated ? RootMoves[i].score : RootMoves[i].prevScore); - std::stringstream s; - - for (int j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++) - s << " " << move_to_uci(RootMoves[i].pv[j], Chess960); - - cout << "info depth " << d - << " seldepth " << selDepth - << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v)) - << " nodes " << pos.nodes_searched() - << " nps " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0) - << " time " << t - << " multipv " << i + 1 - << " pv" << s.str() << endl; - } - } - - - // pv_info_to_log() writes human-readable search information to the log file - // (which is created when the UCI parameter "Use Search Log" is "true"). It - // uses the two below helpers to pretty format time and score respectively. - - string time_to_string(int millisecs) { - - const int MSecMinute = 1000 * 60; - const int MSecHour = 1000 * 60 * 60; - - int hours = millisecs / MSecHour; - int minutes = (millisecs % MSecHour) / MSecMinute; - int seconds = ((millisecs % MSecHour) % MSecMinute) / 1000; - - std::stringstream s; - - if (hours) - s << hours << ':'; - - s << std::setfill('0') << std::setw(2) << minutes << ':' - << std::setw(2) << seconds; - return s.str(); - } - - string score_to_string(Value v) { - - std::stringstream s; - - if (v >= VALUE_MATE_IN_MAX_PLY) - s << "#" << (VALUE_MATE - v + 1) / 2; - else if (v <= VALUE_MATED_IN_MAX_PLY) - s << "-#" << (VALUE_MATE + v) / 2; - else - s << std::setprecision(2) << std::fixed << std::showpos - << float(v) / PawnValueMidgame; - - return s.str(); - } - - void pv_info_to_log(Position& pos, int depth, Value value, int time, Move pv[]) { - - const int64_t K = 1000; - const int64_t M = 1000000; - - StateInfo state[MAX_PLY_PLUS_2], *st = state; - Move* m = pv; - string san, padding; - size_t length; - std::stringstream s; - - s << std::setw(2) << depth - << std::setw(8) << score_to_string(value) - << std::setw(8) << time_to_string(time); - - if (pos.nodes_searched() < M) - s << std::setw(8) << pos.nodes_searched() / 1 << " "; - - else if (pos.nodes_searched() < K * M) - s << std::setw(7) << pos.nodes_searched() / K << "K "; - - else - s << std::setw(7) << pos.nodes_searched() / M << "M "; - - padding = string(s.str().length(), ' '); - length = padding.length(); - - while (*m != MOVE_NONE) - { - san = move_to_san(pos, *m); - - if (length + san.length() > 80) - { - s << "\n" + padding; - length = padding.length(); - } - - s << san << ' '; - length += san.length() + 1; - - pos.do_move(*m++, *st++); - } - - while (m != pv) - pos.undo_move(*--m); - - Log l(Options["Search Log Filename"]); - l << s.str() << endl; - } - - // When playing with strength handicap choose best move among the MultiPV set // using a statistical rule dependent on SkillLevel. Idea by Heinz van Saanen. @@ -1671,12 +1449,12 @@ split_point_start: // At split points actual search starts from here static RKISS rk; // PRNG sequence should be not deterministic - for (int i = Time::current_time().msec() % 50; i > 0; i--) + for (int i = Time::now() % 50; i > 0; i--) rk.rand(); // RootMoves are already sorted by score in descending order size_t size = std::min(MultiPV, RootMoves.size()); - int variance = std::min(RootMoves[0].score - RootMoves[size - 1].score, PawnValueMidgame); + int variance = std::min(RootMoves[0].score - RootMoves[size - 1].score, PawnValueMg); int weakness = 120 - 2 * SkillLevel; int max_s = -VALUE_INFINITE; Move best = MOVE_NONE; @@ -1689,7 +1467,7 @@ split_point_start: // At split points actual search starts from here int s = RootMoves[i].score; // Don't allow crazy blunders even at very low skills - if (i > 0 && RootMoves[i-1].score > s + EasyMoveMargin) + if (i > 0 && RootMoves[i-1].score > s + 2 * PawnValueMg) break; // This is our magic formula @@ -1705,6 +1483,50 @@ split_point_start: // At split points actual search starts from here return best; } + + // uci_pv() formats PV information according to UCI protocol. UCI requires + // to send all the PV lines also if are still to be searched and so refer to + // the previous search score. + + string uci_pv(const Position& pos, int depth, Value alpha, Value beta) { + + std::stringstream s; + Time::point elaspsed = Time::now() - SearchTime + 1; + int selDepth = 0; + + for (size_t i = 0; i < Threads.size(); i++) + if (Threads[i].maxPly > selDepth) + selDepth = Threads[i].maxPly; + + for (size_t i = 0; i < std::min(UCIMultiPV, RootMoves.size()); i++) + { + bool updated = (i <= PVIdx); + + if (depth == 1 && !updated) + continue; + + int d = (updated ? depth : depth - 1); + Value v = (updated ? RootMoves[i].score : RootMoves[i].prevScore); + + if (s.rdbuf()->in_avail()) + s << "\n"; + + s << "info depth " << d + << " seldepth " << selDepth + << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v)) + << " nodes " << pos.nodes_searched() + << " nps " << pos.nodes_searched() * 1000 / elaspsed + << " time " << elaspsed + << " multipv " << i + 1 + << " pv"; + + for (size_t j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++) + s << " " << move_to_uci(RootMoves[i].pv[j], Chess960); + } + + return s.str(); + } + } // namespace @@ -1775,11 +1597,15 @@ void RootMove::insert_pv_in_tt(Position& pos) { } -/// Thread::idle_loop() is where the thread is parked when it has no work to do. -/// The parameter 'master_sp', if non-NULL, is a pointer to an active SplitPoint -/// object for which the thread is the master. +/// Thread::idle_loop() is where the thread is parked when it has no work to do -void Thread::idle_loop(SplitPoint* sp_master) { +void Thread::idle_loop() { + + // Pointer 'sp_master', if non-NULL, points to the active SplitPoint + // object for which the thread is the master. + const SplitPoint* sp_master = splitPointsCnt ? curSplitPoint : NULL; + + assert(!sp_master || (sp_master->master == this && is_searching)); // If this thread is the master of a split point and all slaves have // finished their work at this split point, return from the idle loop. @@ -1798,12 +1624,12 @@ void Thread::idle_loop(SplitPoint* sp_master) { } // Grab the lock to avoid races with Thread::wake_up() - lock_grab(sleepLock); + mutex.lock(); // If we are master and all slaves have finished don't go to sleep if (sp_master && !sp_master->slavesMask) { - lock_release(sleepLock); + mutex.unlock(); break; } @@ -1812,9 +1638,9 @@ void Thread::idle_loop(SplitPoint* sp_master) { // in the meanwhile, allocated us and sent the wake_up() call before we // had the chance to grab the lock. if (do_sleep || !is_searching) - cond_wait(sleepCond, sleepLock); + sleepCondition.wait(mutex); - lock_release(sleepLock); + mutex.unlock(); } // If this thread has been assigned work, launch a search @@ -1822,21 +1648,24 @@ void Thread::idle_loop(SplitPoint* sp_master) { { assert(!do_sleep && !do_exit); - lock_grab(Threads.splitLock); + Threads.mutex.lock(); assert(is_searching); SplitPoint* sp = curSplitPoint; - lock_release(Threads.splitLock); + Threads.mutex.unlock(); Stack ss[MAX_PLY_PLUS_2]; - Position pos(*sp->pos, threadID); - int master = sp->master; + Position pos(*sp->pos, this); memcpy(ss, sp->ss - 1, 4 * sizeof(Stack)); (ss+1)->sp = sp; - lock_grab(sp->lock); + sp->mutex.lock(); + + assert(sp->activePositions[idx] == NULL); + + sp->activePositions[idx] = &pos; if (sp->nodeType == Root) search(pos, ss+1, sp->alpha, sp->beta, sp->depth); @@ -1850,20 +1679,25 @@ void Thread::idle_loop(SplitPoint* sp_master) { assert(is_searching); is_searching = false; - sp->slavesMask &= ~(1ULL << threadID); + sp->activePositions[idx] = NULL; + sp->slavesMask &= ~(1ULL << idx); sp->nodes += pos.nodes_searched(); - // After releasing the lock we cannot access anymore any SplitPoint - // related data in a reliably way becuase it could have been released - // under our feet by the sp master. - lock_release(sp->lock); - // Wake up master thread so to allow it to return from the idle loop in // case we are the last slave of the split point. - if ( Threads.use_sleeping_threads() - && threadID != master - && !Threads[master].is_searching) - Threads[master].wake_up(); + if ( Threads.use_sleeping_threads() + && this != sp->master + && !sp->slavesMask) + { + assert(!sp->master->is_searching); + sp->master->wake_up(); + } + + // After releasing the lock we cannot access anymore any SplitPoint + // related data in a safe way becuase it could have been released under + // our feet by the sp master. Also accessing other Thread objects is + // unsafe because if we are exiting there is a chance are already freed. + sp->mutex.unlock(); } } } @@ -1875,26 +1709,57 @@ void Thread::idle_loop(SplitPoint* sp_master) { void check_time() { - static Time lastInfoTime = Time::current_time(); + static Time::point lastInfoTime = Time::now(); + int64_t nodes = 0; // Workaround silly 'uninitialized' gcc warning - if (lastInfoTime.elapsed() >= 1000) + if (Time::now() - lastInfoTime >= 1000) { - lastInfoTime.restart(); + lastInfoTime = Time::now(); dbg_print(); } if (Limits.ponder) return; - int e = SearchTime.elapsed(); + if (Limits.nodes) + { + Threads.mutex.lock(); + + nodes = RootPosition.nodes_searched(); + + // Loop across all split points and sum accumulated SplitPoint nodes plus + // all the currently active slaves positions. + for (size_t i = 0; i < Threads.size(); i++) + for (int j = 0; j < Threads[i].splitPointsCnt; j++) + { + SplitPoint& sp = Threads[i].splitPoints[j]; + + sp.mutex.lock(); + + nodes += sp.nodes; + Bitboard sm = sp.slavesMask; + while (sm) + { + Position* pos = sp.activePositions[pop_lsb(&sm)]; + nodes += pos ? pos->nodes_searched() : 0; + } + + sp.mutex.unlock(); + } + + Threads.mutex.unlock(); + } + + Time::point elapsed = Time::now() - SearchTime; bool stillAtFirstMove = Signals.firstRootMove && !Signals.failedLowAtRoot - && e > TimeMgr.available_time(); + && elapsed > TimeMgr.available_time(); - bool noMoreTime = e > TimeMgr.maximum_time() - 2 * TimerResolution + bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerResolution || stillAtFirstMove; if ( (Limits.use_time_management() && noMoreTime) - || (Limits.maxTime && e >= Limits.maxTime)) + || (Limits.movetime && elapsed >= Limits.movetime) + || (Limits.nodes && nodes >= Limits.nodes)) Signals.stop = true; }