X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=785cf0efb8ec7ec055f369ec3566c88f9dd87ccf;hp=3b25b6533db24730049f20f156ebffa6b6e82bd3;hb=5436d98fc54600ead011304274250e8b5de35c6a;hpb=e8e5b9f537a4b8b062b48f584f184f254385b276 diff --git a/src/search.cpp b/src/search.cpp index 3b25b653..785cf0ef 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -41,7 +41,7 @@ namespace Search { volatile SignalsType Signals; LimitsType Limits; std::vector RootMoves; - Position RootPosition; + Position RootPos; Color RootColor; Time::point SearchTime; StateStackPtr SetupStates; @@ -87,10 +87,9 @@ namespace { return (Depth) Reductions[PvNode][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)]; } - size_t MultiPV, UCIMultiPV, PVIdx; + size_t PVSize, PVIdx; TimeManager TimeMgr; int BestMoveChanges; - bool Chess960; Value DrawValue[COLOR_NB]; History H; @@ -180,41 +179,28 @@ size_t Search::perft(Position& pos, Depth depth) { /// Search::think() is the external interface to Stockfish's search, and is /// called by the main thread when the program receives the UCI 'go' command. It -/// searches from RootPosition and at the end prints the "bestmove" to output. +/// searches from RootPos and at the end prints the "bestmove" to output. void Search::think() { static PolyglotBook book; // Defined static to initialize the PRNG only once - Position& pos = RootPosition; - Chess960 = pos.is_chess960(); - RootColor = pos.side_to_move(); - TimeMgr.init(Limits, pos.startpos_ply_counter(), pos.side_to_move()); - TT.new_search(); - H.clear(); + RootColor = RootPos.side_to_move(); + TimeMgr.init(Limits, RootPos.startpos_ply_counter(), RootColor); if (RootMoves.empty()) { + RootMoves.push_back(MOVE_NONE); sync_cout << "info depth 0 score " - << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << sync_endl; + << score_to_uci(RootPos.in_check() ? -VALUE_MATE : VALUE_DRAW) + << sync_endl; - RootMoves.push_back(MOVE_NONE); goto finalize; } - if (Options["Contempt Factor"] && !Options["UCI_AnalyseMode"]) - { - int cf = Options["Contempt Factor"] * PawnValueMg / 100; // In centipawns - cf = cf * MaterialTable::game_phase(pos) / PHASE_MIDGAME; // Scale down with phase - DrawValue[ RootColor] = VALUE_DRAW - Value(cf); - DrawValue[~RootColor] = VALUE_DRAW + Value(cf); - } - else - DrawValue[WHITE] = DrawValue[BLACK] = VALUE_DRAW; - if (Options["OwnBook"] && !Limits.infinite) { - Move bookMove = book.probe(pos, Options["Book File"], Options["Best Book Move"]); + Move bookMove = book.probe(RootPos, Options["Book File"], Options["Best Book Move"]); if (bookMove && std::count(RootMoves.begin(), RootMoves.end(), bookMove)) { @@ -223,14 +209,24 @@ void Search::think() { } } + if (Options["Contempt Factor"] && !Options["UCI_AnalyseMode"]) + { + int cf = Options["Contempt Factor"] * PawnValueMg / 100; // From centipawns + cf = cf * MaterialTable::game_phase(RootPos) / PHASE_MIDGAME; // Scale down with phase + DrawValue[ RootColor] = VALUE_DRAW - Value(cf); + DrawValue[~RootColor] = VALUE_DRAW + Value(cf); + } + else + DrawValue[WHITE] = DrawValue[BLACK] = VALUE_DRAW; + if (Options["Use Search Log"]) { Log log(Options["Search Log Filename"]); - log << "\nSearching: " << pos.to_fen() + log << "\nSearching: " << RootPos.to_fen() << "\ninfinite: " << Limits.infinite << " ponder: " << Limits.ponder - << " time: " << Limits.time[pos.side_to_move()] - << " increment: " << Limits.inc[pos.side_to_move()] + << " time: " << Limits.time[RootColor] + << " increment: " << Limits.inc[RootColor] << " moves to go: " << Limits.movestogo << std::endl; } @@ -240,14 +236,14 @@ void Search::think() { // 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))); + 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); + id_loop(RootPos); // Let's start searching ! Threads.set_timer(0); // Stop timer Threads.sleep(); @@ -257,14 +253,14 @@ void Search::think() { Time::point elapsed = Time::now() - SearchTime + 1; Log log(Options["Search Log Filename"]); - log << "Nodes: " << pos.nodes_searched() - << "\nNodes/second: " << pos.nodes_searched() * 1000 / elapsed - << "\nBest move: " << move_to_san(pos, RootMoves[0].pv[0]); + log << "Nodes: " << RootPos.nodes_searched() + << "\nNodes/second: " << RootPos.nodes_searched() * 1000 / elapsed + << "\nBest move: " << move_to_san(RootPos, 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]) << std::endl; - pos.undo_move(RootMoves[0].pv[0]); + RootPos.do_move(RootMoves[0].pv[0], st); + log << "\nPonder move: " << move_to_san(RootPos, RootMoves[0].pv[1]) << std::endl; + RootPos.undo_move(RootMoves[0].pv[0]); } finalize: @@ -273,11 +269,12 @@ 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)) - pos.this_thread()->wait_for_stop_or_ponderhit(); + RootPos.this_thread()->wait_for_stop_or_ponderhit(); // Best move could be MOVE_NONE when searching on a stalemate position - sync_cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], Chess960) - << " ponder " << move_to_uci(RootMoves[0].pv[1], Chess960) << sync_endl; + sync_cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], RootPos.is_chess960()) + << " ponder " << move_to_uci(RootMoves[0].pv[1], RootPos.is_chess960()) + << sync_endl; } @@ -298,13 +295,18 @@ namespace { depth = BestMoveChanges = 0; bestValue = delta = -VALUE_INFINITE; ss->currentMove = MOVE_NULL; // Hack to skip update gains + TT.new_search(); + H.clear(); - UCIMultiPV = Options["MultiPV"]; + PVSize = Options["MultiPV"]; Skill skill(Options["Skill Level"]); - // Do we have to play with skill handicap? In this case enable MultiPV that - // we will use behind the scenes to retrieve a set of possible moves. - MultiPV = skill.enabled() ? std::max(UCIMultiPV, (size_t)4) : UCIMultiPV; + // Do we have to play with skill handicap? In this case enable MultiPV search + // that we will use behind the scenes to retrieve a set of possible moves. + if (skill.enabled() && PVSize < 4) + PVSize = 4; + + PVSize = std::min(PVSize, RootMoves.size()); // Iterative deepening loop until requested to stop or target depth reached while (++depth <= MAX_PLY && !Signals.stop && (!Limits.depth || depth <= Limits.depth)) @@ -314,11 +316,11 @@ namespace { for (size_t i = 0; i < RootMoves.size(); i++) RootMoves[i].prevScore = RootMoves[i].score; - prevBestMoveChanges = BestMoveChanges; + prevBestMoveChanges = BestMoveChanges; // Only sensible when PVSize == 1 BestMoveChanges = 0; // MultiPV loop. We perform a full root search for each PV line - for (PVIdx = 0; PVIdx < std::min(MultiPV, RootMoves.size()); PVIdx++) + for (PVIdx = 0; PVIdx < PVSize; PVIdx++) { // Set aspiration window default width if (depth >= 5 && abs(RootMoves[PVIdx].prevScore) < VALUE_KNOWN_WIN) @@ -417,7 +419,7 @@ namespace { bool stop = false; // Local variable, not the volatile Signals.stop // Take in account some extra time if the best move has changed - if (depth > 4 && depth < 50) + if (depth > 4 && depth < 50 && PVSize == 1) TimeMgr.pv_instability(BestMoveChanges, prevBestMoveChanges); // Stop search if most of available time is already consumed. We @@ -429,6 +431,7 @@ namespace { // Stop search early if one move seems to be much better than others if ( depth >= 12 && !stop + && PVSize == 1 && ( (bestMoveNeverChanged && pos.captured_piece_type()) || Time::now() - SearchTime > (TimeMgr.available_time() * 40) / 100)) { @@ -521,7 +524,7 @@ namespace { if (!RootNode) { // Step 2. Check for aborted search and immediate draw - if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) + if (Signals.stop || (PvNode?pos.is_draw():pos.is_draw()) || ss->ply > MAX_PLY) return DrawValue[pos.side_to_move()]; // Step 3. Mate distance pruning. Even if we mate at the next move our score @@ -790,7 +793,7 @@ split_point_start: // At split points actual search starts from here if (thisThread == Threads.main_thread() && Time::now() - SearchTime > 2000) sync_cout << "info depth " << depth / ONE_PLY - << " currmove " << move_to_uci(move, Chess960) + << " currmove " << move_to_uci(move, pos.is_chess960()) << " currmovenumber " << moveCount + PVIdx << sync_endl; } @@ -955,7 +958,7 @@ split_point_start: // At split points actual search starts from here // 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 (Signals.stop || thisThread->cutoff_occurred()) - return bestValue; + return value; // To avoid returning VALUE_INFINITE if (RootNode) { @@ -970,7 +973,7 @@ 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 (!pvMove && MultiPV == 1) + if (!pvMove) BestMoveChanges++; } else @@ -1100,7 +1103,7 @@ split_point_start: // At split points actual search starts from here ss->ply = (ss-1)->ply + 1; // Check for an instant draw or maximum ply reached - if (pos.is_draw() || ss->ply > MAX_PLY) + if (pos.is_draw() || ss->ply > MAX_PLY) return DrawValue[pos.side_to_move()]; // Transposition table lookup. At PV nodes, we don't use the TT for @@ -1443,8 +1446,6 @@ split_point_start: // At split points actual search starts from here Move Skill::pick_move() { - assert(MultiPV > 1); - static RKISS rk; // PRNG sequence should be not deterministic @@ -1452,8 +1453,7 @@ split_point_start: // At split points actual search starts from here 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, PawnValueMg); + int variance = std::min(RootMoves[0].score - RootMoves[PVSize - 1].score, PawnValueMg); int weakness = 120 - 2 * level; int max_s = -VALUE_INFINITE; best = MOVE_NONE; @@ -1461,7 +1461,7 @@ split_point_start: // At split points actual search starts from here // Choose best move. For each move score we add two terms both dependent on // weakness, one deterministic and bigger for weaker moves, and one random, // then we choose the move with the resulting highest score. - for (size_t i = 0; i < size; i++) + for (size_t i = 0; i < PVSize; i++) { int s = RootMoves[i].score; @@ -1497,7 +1497,7 @@ split_point_start: // At split points actual search starts from here if (Threads[i].maxPly > selDepth) selDepth = Threads[i].maxPly; - for (size_t i = 0; i < std::min(UCIMultiPV, RootMoves.size()); i++) + for (size_t i = 0; i < std::min((size_t)Options["MultiPV"], RootMoves.size()); i++) { bool updated = (i <= PVIdx); @@ -1520,7 +1520,7 @@ split_point_start: // At split points actual search starts from here << " pv"; for (size_t j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++) - s << " " << move_to_uci(RootMoves[i].pv[j], Chess960); + s << " " << move_to_uci(RootMoves[i].pv[j], pos.is_chess960()); } return s.str(); @@ -1552,7 +1552,7 @@ void RootMove::extract_pv_from_tt(Position& pos) { && pos.is_pseudo_legal(m) && pos.pl_move_is_legal(m, pos.pinned_pieces()) && ply < MAX_PLY - && (!pos.is_draw() || ply < 2)) + && (!pos.is_draw() || ply < 2)) { pv.push_back(m); pos.do_move(m, *st++); @@ -1724,7 +1724,7 @@ void check_time() { { Threads.mutex.lock(); - nodes = RootPosition.nodes_searched(); + nodes = RootPos.nodes_searched(); // Loop across all split points and sum accumulated SplitPoint nodes plus // all the currently active slaves positions.