X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=8f9a369ae23d86a9a4d62d046a8f35ea4c9f6013;hp=ad13c4ba304c1a898d0a5684504d68c7e7fee47b;hb=ffedfa33542a7de7d87fd545ea0a4b2fef8f8c6e;hpb=67f88f5e3e4ee6e4b49151173c2898253178506f diff --git a/src/search.cpp b/src/search.cpp index ad13c4ba..8f9a369a 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -25,11 +25,11 @@ #include #include -#include "book.h" #include "evaluate.h" #include "movegen.h" #include "movepick.h" #include "notation.h" +#include "rkiss.h" #include "search.h" #include "timeman.h" #include "thread.h" @@ -42,8 +42,7 @@ namespace Search { LimitsType Limits; std::vector RootMoves; Position RootPos; - Color RootColor; - Time::point SearchTime, IterationTime; + Time::point SearchTime; StateStackPtr SetupStates; } @@ -57,16 +56,16 @@ namespace { const bool FakeSplit = false; // Different node types, used as template parameter - enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV }; + enum NodeType { Root, PV, NonPV }; // Dynamic razoring margin based on depth - inline Value razor_margin(Depth d) { return Value(512 + 16 * int(d)); } + inline Value razor_margin(Depth d) { return Value(512 + 16 * d); } // Futility lookup tables (initialized at startup) and their access functions int FutilityMoveCounts[2][32]; // [improving][depth] inline Value futility_margin(Depth d) { - return Value(100 * int(d)); + return Value(100 * d); } // Reduction lookup tables (initialized at startup) and their access function @@ -77,7 +76,7 @@ namespace { return (Depth) Reductions[PvNode][i][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)]; } - size_t PVSize, PVIdx; + size_t MultiPV, PVIdx; TimeManager TimeMgr; double BestMoveChanges; Value DrawValue[COLOR_NB]; @@ -85,7 +84,7 @@ namespace { GainsStats Gains; MovesStats Countermoves, Followupmoves; - template + template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode); template @@ -94,7 +93,7 @@ namespace { void id_loop(Position& pos); Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); - void update_stats(Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt); + void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt); string uci_pv(const Position& pos, int depth, Value alpha, Value beta); struct Skill { @@ -127,10 +126,10 @@ void Search::init() { // Init reductions array for (hd = 1; hd < 64; ++hd) for (mc = 1; mc < 64; ++mc) { - double pvRed = log(double(hd)) * log(double(mc)) / 3.0; + double pvRed = 0.00 + log(double(hd)) * log(double(mc)) / 3.00; double nonPVRed = 0.33 + log(double(hd)) * log(double(mc)) / 2.25; - Reductions[1][1][hd][mc] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(ONE_PLY)) : 0); - Reductions[0][1][hd][mc] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(ONE_PLY)) : 0); + Reductions[1][1][hd][mc] = int8_t( pvRed >= 1.0 ? pvRed * int(ONE_PLY) : 0); + Reductions[0][1][hd][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed * int(ONE_PLY) : 0); Reductions[1][0][hd][mc] = Reductions[1][1][hd][mc]; Reductions[0][0][hd][mc] = Reductions[0][1][hd][mc]; @@ -145,8 +144,8 @@ void Search::init() { // Init futility move count array for (d = 0; d < 32; ++d) { - FutilityMoveCounts[0][d] = int(2.4 + 0.222 * pow(d + 0.0, 1.8)); - FutilityMoveCounts[1][d] = int(3.0 + 0.3 * pow(d + 0.98, 1.8)); + FutilityMoveCounts[0][d] = int(2.4 + 0.222 * pow(d + 0.00, 1.8)); + FutilityMoveCounts[1][d] = int(3.0 + 0.300 * pow(d + 0.98, 1.8)); } } @@ -180,10 +179,11 @@ uint64_t Search::perft(Position& pos, Depth depth) { void Search::think() { - static PolyglotBook book; // Defined static to initialize the PRNG only once + TimeMgr.init(Limits, RootPos.game_ply(), RootPos.side_to_move()); - RootColor = RootPos.side_to_move(); - TimeMgr.init(Limits, RootPos.game_ply(), RootColor); + int cf = Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns + DrawValue[ RootPos.side_to_move()] = VALUE_DRAW - Value(cf); + DrawValue[~RootPos.side_to_move()] = VALUE_DRAW + Value(cf); if (RootMoves.empty()) { @@ -195,51 +195,28 @@ void Search::think() { goto finalize; } - if (Options["OwnBook"] && !Limits.infinite && !Limits.mate) - { - Move bookMove = book.probe(RootPos, Options["Book File"], Options["Best Book Move"]); - - if (bookMove && std::count(RootMoves.begin(), RootMoves.end(), bookMove)) - { - std::swap(RootMoves[0], *std::find(RootMoves.begin(), RootMoves.end(), bookMove)); - goto finalize; - } - } - - if (Options["Contempt Factor"] && !Options["UCI_AnalyseMode"]) - { - int cf = Options["Contempt Factor"] * PawnValueMg / 100; // From centipawns - cf = cf * Material::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["Write Search Log"]) { Log log(Options["Search Log Filename"]); log << "\nSearching: " << RootPos.fen() << "\ninfinite: " << Limits.infinite << " ponder: " << Limits.ponder - << " time: " << Limits.time[RootColor] - << " increment: " << Limits.inc[RootColor] + << " time: " << Limits.time[RootPos.side_to_move()] + << " increment: " << Limits.inc[RootPos.side_to_move()] << " moves to go: " << Limits.movestogo - << std::endl; + << "\n" << std::endl; } // Reset the threads, still sleeping: will wake up at split time for (size_t i = 0; i < Threads.size(); ++i) Threads[i]->maxPly = 0; - Threads.sleepWhileIdle = Options["Idle Threads Sleep"]; Threads.timer->run = true; Threads.timer->notify_one(); // Wake up the recurring timer id_loop(RootPos); // Let's start searching ! Threads.timer->run = false; // Stop the timer - Threads.sleepWhileIdle = true; // Send idle threads to sleep if (Options["Write Search Log"]) { @@ -293,7 +270,6 @@ namespace { Value bestValue, alpha, beta, delta; std::memset(ss-2, 0, 5 * sizeof(Stack)); - (ss-1)->currentMove = MOVE_NULL; // Hack to skip update gains depth = 0; BestMoveChanges = 0; @@ -306,15 +282,15 @@ namespace { Countermoves.clear(); Followupmoves.clear(); - PVSize = Options["MultiPV"]; + MultiPV = Options["MultiPV"]; Skill skill(Options["Skill Level"]); // 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; + if (skill.enabled() && MultiPV < 4) + MultiPV = 4; - PVSize = std::min(PVSize, RootMoves.size()); + MultiPV = std::min(MultiPV, RootMoves.size()); // Iterative deepening loop until requested to stop or target depth reached while (++depth <= MAX_PLY && !Signals.stop && (!Limits.depth || depth <= Limits.depth)) @@ -328,7 +304,7 @@ namespace { RootMoves[i].prevScore = RootMoves[i].score; // MultiPV loop. We perform a full root search for each PV line - for (PVIdx = 0; PVIdx < PVSize && !Signals.stop; ++PVIdx) + for (PVIdx = 0; PVIdx < MultiPV && !Signals.stop; ++PVIdx) { // Reset aspiration window starting size if (depth >= 5) @@ -343,7 +319,7 @@ namespace { // high/low anymore. while (true) { - bestValue = search(pos, ss, alpha, beta, depth * ONE_PLY, false); + bestValue = search(pos, ss, alpha, beta, depth * ONE_PLY, false); // Bring the best move to the front. It is critical that sorting // is done with a stable algorithm because all the values but the @@ -393,12 +369,10 @@ namespace { // Sort the PV lines searched so far and update the GUI std::stable_sort(RootMoves.begin(), RootMoves.begin() + PVIdx + 1); - if (PVIdx + 1 == PVSize || Time::now() - SearchTime > 3000) + if (PVIdx + 1 == MultiPV || Time::now() - SearchTime > 3000) sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl; } - IterationTime = Time::now() - SearchTime; - // If skill levels are enabled and time is up, pick a sub-optimal best move if (skill.enabled() && skill.time_to_pick(depth)) skill.pick_move(); @@ -423,19 +397,14 @@ namespace { // Do we have time for the next iteration? Can we stop searching now? if (Limits.use_time_management() && !Signals.stop && !Signals.stopOnPonderhit) { - bool stop = false; // Local variable, not the volatile Signals.stop - // Take some extra time if the best move has changed - if (depth > 4 && depth < 50 && PVSize == 1) + if (depth > 4 && depth < 50 && MultiPV == 1) TimeMgr.pv_instability(BestMoveChanges); // Stop the search if only one legal move is available or all // of the available time has been used. if ( RootMoves.size() == 1 - || IterationTime > TimeMgr.available_time() ) - stop = true; - - if (stop) + || Time::now() - SearchTime > TimeMgr.available_time()) { // If we are allowed to ponder do not stop the search now but // keep pondering until the GUI sends "ponderhit" or "stop". @@ -456,14 +425,13 @@ namespace { // repeat 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, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode) { - const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV || NT == SplitPointRoot); - const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV || NT == SplitPointRoot); - const bool RootNode = (NT == Root || NT == SplitPointRoot); + const bool RootNode = NT == Root; + const bool PvNode = NT == PV || NT == Root; - assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); + assert(-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE); assert(PvNode || (alpha == beta - 1)); assert(depth > DEPTH_ZERO); @@ -547,7 +515,6 @@ namespace { : ttValue >= beta ? (tte->bound() & BOUND_LOWER) : (tte->bound() & BOUND_UPPER))) { - TT.refresh(tte); ss->currentMove = ttMove; // Can be MOVE_NONE // If ttMove is quiet, update killers, history, counter move and followup move on TT hit @@ -577,7 +544,9 @@ namespace { } else { - eval = ss->staticEval = evaluate(pos); + eval = ss->staticEval = + (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo; + TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval); } @@ -585,6 +554,7 @@ namespace { && ss->staticEval != VALUE_NONE && (ss-1)->staticEval != VALUE_NONE && (move = (ss-1)->currentMove) != MOVE_NULL + && move != MOVE_NONE && type_of(move) == NORMAL) { Square to = to_sq(move); @@ -596,9 +566,12 @@ namespace { && depth < 4 * ONE_PLY && eval + razor_margin(depth) <= alpha && ttMove == MOVE_NONE - && abs(beta) < VALUE_MATE_IN_MAX_PLY && !pos.pawn_on_7th(pos.side_to_move())) { + if ( depth <= ONE_PLY + && eval + razor_margin(3 * ONE_PLY) <= alpha) + return qsearch(pos, ss, alpha, beta, DEPTH_ZERO); + Value ralpha = alpha - razor_margin(depth); Value v = qsearch(pos, ss, ralpha, ralpha+1, DEPTH_ZERO); if (v <= ralpha) @@ -620,7 +593,6 @@ namespace { && !ss->skipNullMove && depth >= 2 * ONE_PLY && eval >= beta - && abs(beta) < VALUE_MATE_IN_MAX_PLY && pos.non_pawn_material(pos.side_to_move())) { ss->currentMove = MOVE_NULL; @@ -630,12 +602,13 @@ namespace { // Null move dynamic reduction based on depth and value Depth R = 3 * ONE_PLY + depth / 4 - + int(eval - beta) / PawnValueMg * ONE_PLY; + + (abs(beta) < VALUE_KNOWN_WIN ? int(eval - beta) / PawnValueMg * ONE_PLY + : DEPTH_ZERO); pos.do_null_move(st); (ss+1)->skipNullMove = true; nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -beta+1, DEPTH_ZERO) - : - search(pos, ss+1, -beta, -beta+1, depth-R, !cutNode); + : - search(pos, ss+1, -beta, -beta+1, depth-R, !cutNode); (ss+1)->skipNullMove = false; pos.undo_null_move(); @@ -645,13 +618,13 @@ namespace { if (nullValue >= VALUE_MATE_IN_MAX_PLY) nullValue = beta; - if (depth < 12 * ONE_PLY) + if (depth < 12 * ONE_PLY && abs(beta) < VALUE_KNOWN_WIN) return nullValue; // Do verification search at high depths ss->skipNullMove = true; Value v = depth-R < ONE_PLY ? qsearch(pos, ss, beta-1, beta, DEPTH_ZERO) - : search(pos, ss, beta-1, beta, depth-R, false); + : search(pos, ss, beta-1, beta, depth-R, false); ss->skipNullMove = false; if (v >= beta) @@ -668,8 +641,8 @@ namespace { && !ss->skipNullMove && abs(beta) < VALUE_MATE_IN_MAX_PLY) { - Value rbeta = beta + 200; - Depth rdepth = depth - ONE_PLY - 3 * ONE_PLY; + Value rbeta = std::min(beta + 200, VALUE_INFINITE); + Depth rdepth = depth - 4 * ONE_PLY; assert(rdepth >= ONE_PLY); assert((ss-1)->currentMove != MOVE_NONE); @@ -683,7 +656,7 @@ namespace { { ss->currentMove = move; pos.do_move(move, st, ci, pos.gives_check(move, ci)); - value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode); + value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode); pos.undo_move(move); if (value >= rbeta) return value; @@ -691,14 +664,14 @@ namespace { } // Step 10. Internal iterative deepening (skipped when in check) - if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY) - && ttMove == MOVE_NONE - && (PvNode || ss->staticEval + Value(256) >= beta)) + if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY) + && !ttMove + && (PvNode || ss->staticEval + 256 >= beta)) { Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4); ss->skipNullMove = true; - search(pos, ss, alpha, beta, d, true); + search(pos, ss, alpha, beta, d, true); ss->skipNullMove = false; tte = TT.probe(posKey); @@ -725,7 +698,10 @@ moves_loop: // When in check and at SpNode search starts from here singularExtensionNode = !RootNode && !SpNode && depth >= 8 * ONE_PLY + && abs(beta) < VALUE_KNOWN_WIN && ttMove != MOVE_NONE + /* && ttValue != VALUE_NONE Already implicit in the next condition */ + && abs(ttValue) < VALUE_KNOWN_WIN && !excludedMove // Recursive singular search is not allowed && (tte->bound() & BOUND_LOWER) && tte->depth() >= depth - 3 * ONE_PLY; @@ -779,7 +755,7 @@ moves_loop: // When in check and at SpNode search starts from here || pos.advanced_pawn_push(move); // Step 12. Extend checks - if (givesCheck && pos.see_sign(move) >= 0) + if (givesCheck && pos.see_sign(move) >= VALUE_ZERO) ext = ONE_PLY; // Singular extension search. If all moves but one fail low on a search of @@ -790,15 +766,12 @@ moves_loop: // When in check and at SpNode search starts from here if ( singularExtensionNode && move == ttMove && !ext - && pos.legal(move, ci.pinned) - && abs(ttValue) < VALUE_KNOWN_WIN) + && pos.legal(move, ci.pinned)) { - assert(ttValue != VALUE_NONE); - Value rBeta = ttValue - int(depth); ss->excludedMove = move; ss->skipNullMove = true; - value = search(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode); + value = search(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode); ss->skipNullMove = false; ss->excludedMove = MOVE_NONE; @@ -833,7 +806,7 @@ moves_loop: // When in check and at SpNode search starts from here if (predictedDepth < 7 * ONE_PLY) { futilityValue = ss->staticEval + futility_margin(predictedDepth) - + Value(128) + Gains[pos.moved_piece(move)][to_sq(move)]; + + 128 + Gains[pos.moved_piece(move)][to_sq(move)]; if (futilityValue <= alpha) { @@ -850,7 +823,7 @@ moves_loop: // When in check and at SpNode search starts from here } // Prune moves with negative SEE at low depths - if (predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < 0) + if (predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < VALUE_ZERO) { if (SpNode) splitPoint->mutex.lock(); @@ -894,17 +867,24 @@ moves_loop: // When in check and at SpNode search starts from here if (move == countermoves[0] || move == countermoves[1]) ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY); + // Decrease reduction for moves that escape a capture + if ( ss->reduction + && type_of(move) == NORMAL + && type_of(pos.piece_on(to_sq(move))) != PAWN + && pos.see(make_move(to_sq(move), from_sq(move))) < 0) + ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY); + Depth d = std::max(newDepth - ss->reduction, ONE_PLY); if (SpNode) alpha = splitPoint->alpha; - value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); + value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); - // Research at intermediate depth if reduction is very high + // Re-search at intermediate depth if reduction is very high if (value > alpha && ss->reduction >= 4 * ONE_PLY) { Depth d2 = std::max(newDepth - 2 * ONE_PLY, ONE_PLY); - value = -search(pos, ss+1, -(alpha+1), -alpha, d2, true); + value = -search(pos, ss+1, -(alpha+1), -alpha, d2, true); } doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO); @@ -922,7 +902,7 @@ moves_loop: // When in check and at SpNode search starts from here value = newDepth < ONE_PLY ? givesCheck ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO) : -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO) - : - search(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode); + : - search(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode); } // For PV nodes only, do a full PV search on the first move or after a fail @@ -932,7 +912,7 @@ moves_loop: // When in check and at SpNode search starts from here value = newDepth < ONE_PLY ? givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) : -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) - : - search(pos, ss+1, -beta, -alpha, newDepth, false); + : - search(pos, ss+1, -beta, -alpha, newDepth, false); // Step 17. Undo move pos.undo_move(move); @@ -946,12 +926,11 @@ moves_loop: // When in check and at SpNode search starts from here alpha = splitPoint->alpha; } - // Finished searching the move. If Signals.stop 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 don't update the best move and/or PV. + // Finished searching the move. If a stop or a cutoff occurred, the return + // value of the search cannot be trusted, and we return immediately without + // updating best move, PV and TT. if (Signals.stop || thisThread->cutoff_occurred()) - return value; // To avoid returning VALUE_INFINITE + return VALUE_ZERO; if (RootNode) { @@ -1000,14 +979,20 @@ moves_loop: // When in check and at SpNode search starts from here // Step 19. Check for splitting the search if ( !SpNode + && Threads.size() >= 2 && depth >= Threads.minimumSplitDepth - && Threads.available_slave(thisThread) + && ( !thisThread->activeSplitPoint + || !thisThread->activeSplitPoint->allSlavesSearching) && thisThread->splitPointsSize < MAX_SPLITPOINTS_PER_THREAD) { - assert(bestValue < beta); + assert(bestValue > -VALUE_INFINITE && bestValue < beta); thisThread->split(pos, ss, alpha, beta, &bestValue, &bestMove, depth, moveCount, &mp, NT, cutNode); + + if (Signals.stop || thisThread->cutoff_occurred()) + return VALUE_ZERO; + if (bestValue >= beta) break; } @@ -1016,30 +1001,31 @@ moves_loop: // When in check and at SpNode search starts from here if (SpNode) return bestValue; + // Following condition would detect a stop or a cutoff set only after move + // loop has been completed. But in this case bestValue is valid because we + // have fully searched our subtree, and we can anyhow save the result in TT. + /* + if (Signals.stop || thisThread->cutoff_occurred()) + return VALUE_DRAW; + */ + // 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. + // must be mate or stalemate. If we are in a singular extension search then + // return a fail low score. if (!moveCount) - return excludedMove ? alpha - : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; + bestValue = excludedMove ? alpha + : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; - // If we have pruned all the moves without searching return a fail-low score - if (bestValue == -VALUE_INFINITE) - bestValue = alpha; + // Quiet best move: update killers, history, countermoves and followupmoves + else if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck) + update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1); TT.store(posKey, value_to_tt(bestValue, ss->ply), bestValue >= beta ? BOUND_LOWER : PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER, depth, bestMove, ss->staticEval); - // Quiet best move: update killers, history, countermoves and followupmoves - if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck) - update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1); - assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); return bestValue; @@ -1053,7 +1039,7 @@ moves_loop: // When in check and at SpNode search starts from here template Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) { - const bool PvNode = (NT == PV); + const bool PvNode = NT == PV; assert(NT == PV || NT == NonPV); assert(InCheck == !!pos.checkers()); @@ -1123,7 +1109,8 @@ moves_loop: // When in check and at SpNode search starts from here bestValue = ttValue; } else - ss->staticEval = bestValue = evaluate(pos); + ss->staticEval = bestValue = + (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo; // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) @@ -1138,7 +1125,7 @@ moves_loop: // When in check and at SpNode search starts from here if (PvNode && bestValue > alpha) alpha = bestValue; - futilityBase = bestValue + Value(128); + futilityBase = bestValue + 128; } // Initialize a MovePicker object for the current position, and prepare @@ -1175,7 +1162,7 @@ moves_loop: // When in check and at SpNode search starts from here continue; } - if (futilityBase < beta && pos.see(move) <= 0) + if (futilityBase < beta && pos.see(move) <= VALUE_ZERO) { bestValue = std::max(bestValue, futilityBase); continue; @@ -1193,7 +1180,7 @@ moves_loop: // When in check and at SpNode search starts from here && (!InCheck || evasionPrunable) && move != ttMove && type_of(move) != PROMOTION - && pos.see_sign(move) < 0) + && pos.see_sign(move) < VALUE_ZERO) continue; // Check for legality just before making the move @@ -1276,7 +1263,7 @@ moves_loop: // When in check and at SpNode search starts from here // update_stats() updates killers, history, countermoves and followupmoves stats after a fail-high // of a quiet move. - void update_stats(Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) { + void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) { if (ss->killers[0] != move) { @@ -1320,7 +1307,7 @@ moves_loop: // When in check and at SpNode search starts from here rk.rand(); // RootMoves are already sorted by score in descending order - int variance = std::min(RootMoves[0].score - RootMoves[PVSize - 1].score, PawnValueMg); + int variance = std::min(RootMoves[0].score - RootMoves[MultiPV - 1].score, PawnValueMg); int weakness = 120 - 2 * level; int max_s = -VALUE_INFINITE; best = MOVE_NONE; @@ -1328,7 +1315,7 @@ moves_loop: // When in check and at SpNode 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 < PVSize; ++i) + for (size_t i = 0; i < MultiPV; ++i) { int s = RootMoves[i].score; @@ -1356,7 +1343,7 @@ moves_loop: // When in check and at SpNode search starts from here string uci_pv(const Position& pos, int depth, Value alpha, Value beta) { - std::stringstream s; + std::stringstream ss; Time::point elapsed = Time::now() - SearchTime + 1; size_t uciPVSize = std::min((size_t)Options["MultiPV"], RootMoves.size()); int selDepth = 0; @@ -1375,23 +1362,23 @@ moves_loop: // When in check and at SpNode search starts from here int d = updated ? depth : depth - 1; Value v = updated ? RootMoves[i].score : RootMoves[i].prevScore; - if (s.rdbuf()->in_avail()) // Not at first line - s << "\n"; + if (ss.rdbuf()->in_avail()) // Not at first line + ss << "\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 / elapsed - << " time " << elapsed - << " multipv " << i + 1 - << " pv"; + ss << "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 / elapsed + << " time " << elapsed + << " multipv " << i + 1 + << " pv"; for (size_t j = 0; RootMoves[i].pv[j] != MOVE_NONE; ++j) - s << " " << move_to_uci(RootMoves[i].pv[j], pos.is_chess960()); + ss << " " << move_to_uci(RootMoves[i].pv[j], pos.is_chess960()); } - return s.str(); + return ss.str(); } } // namespace @@ -1406,28 +1393,31 @@ void RootMove::extract_pv_from_tt(Position& pos) { StateInfo state[MAX_PLY_PLUS_6], *st = state; const TTEntry* tte; - int ply = 0; - Move m = pv[0]; + int ply = 1; // At root ply is 1... + Move m = pv[0]; // ...instead pv[] array starts from 0 + Value expectedScore = score; pv.clear(); do { pv.push_back(m); - assert(MoveList(pos).contains(pv[ply])); + assert(MoveList(pos).contains(pv[ply - 1])); - pos.do_move(pv[ply++], *st++); + pos.do_move(pv[ply++ - 1], *st++); tte = TT.probe(pos.key()); + expectedScore = -expectedScore; } while ( tte + && expectedScore == value_from_tt(tte->value(), ply) && pos.pseudo_legal(m = tte->move()) // Local copy, TT could change && pos.legal(m, pos.pinned_pieces(pos.side_to_move())) && ply < MAX_PLY - && (!pos.is_draw() || ply < 2)); + && (!pos.is_draw() || ply <= 2)); pv.push_back(MOVE_NONE); // Must be zero-terminating - while (ply) pos.undo_move(pv[--ply]); + while (--ply) pos.undo_move(pv[ply - 1]); } @@ -1439,21 +1429,21 @@ void RootMove::insert_pv_in_tt(Position& pos) { StateInfo state[MAX_PLY_PLUS_6], *st = state; const TTEntry* tte; - int ply = 0; + int idx = 0; // Ply starts from 1, we need to start from 0 do { tte = TT.probe(pos.key()); - if (!tte || tte->move() != pv[ply]) // Don't overwrite correct entries - TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply], VALUE_NONE); + if (!tte || tte->move() != pv[idx]) // Don't overwrite correct entries + TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[idx], VALUE_NONE); - assert(MoveList(pos).contains(pv[ply])); + assert(MoveList(pos).contains(pv[idx])); - pos.do_move(pv[ply++], *st++); + pos.do_move(pv[idx++], *st++); - } while (pv[ply] != MOVE_NONE); + } while (pv[idx] != MOVE_NONE); - while (ply) pos.undo_move(pv[--ply]); + while (idx) pos.undo_move(pv[--idx]); } @@ -1471,7 +1461,7 @@ void Thread::idle_loop() { { // If we are not searching, wait for a condition to be signaled instead of // wasting CPU time polling for work. - while ((!searching && Threads.sleepWhileIdle) || exit) + while (!searching || exit) { if (exit) { @@ -1483,7 +1473,7 @@ void Thread::idle_loop() { mutex.lock(); // If we are master and all slaves have finished then exit idle_loop - if (this_sp && !this_sp->slavesMask) + if (this_sp && this_sp->slavesMask.none()) { mutex.unlock(); break; @@ -1524,32 +1514,30 @@ void Thread::idle_loop() { activePosition = &pos; - switch (sp->nodeType) { - case Root: - search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); - break; - case PV: - search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); - break; - case NonPV: - search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); - break; - default: + if (sp->nodeType == NonPV) + search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); + + else if (sp->nodeType == PV) + search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); + + else if (sp->nodeType == Root) + search(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode); + + else assert(false); - } assert(searching); searching = false; activePosition = NULL; - sp->slavesMask &= ~(1ULL << idx); + sp->slavesMask.reset(idx); + sp->allSlavesSearching = false; sp->nodes += pos.nodes_searched(); // Wake up the 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.sleepWhileIdle - && this != sp->masterThread - && !sp->slavesMask) + if ( this != sp->masterThread + && sp->slavesMask.none()) { assert(!sp->masterThread->searching); sp->masterThread->notify_one(); @@ -1557,17 +1545,47 @@ void Thread::idle_loop() { // After releasing the lock we can't access any SplitPoint related data // in a safe way because 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 that they are already freed. + // the sp master. sp->mutex.unlock(); + + // Try to late join to another split point if none of its slaves has + // already finished. + if (Threads.size() > 2) + for (size_t i = 0; i < Threads.size(); ++i) + { + const int size = Threads[i]->splitPointsSize; // Local copy + sp = size ? &Threads[i]->splitPoints[size - 1] : NULL; + + if ( sp + && sp->allSlavesSearching + && available_to(Threads[i])) + { + // Recheck the conditions under lock protection + Threads.mutex.lock(); + sp->mutex.lock(); + + if ( sp->allSlavesSearching + && available_to(Threads[i])) + { + sp->slavesMask.set(idx); + activeSplitPoint = sp; + searching = true; + } + + sp->mutex.unlock(); + Threads.mutex.unlock(); + + break; // Just a single attempt + } + } } // 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. - if (this_sp && !this_sp->slavesMask) + if (this_sp && this_sp->slavesMask.none()) { this_sp->mutex.lock(); - bool finished = !this_sp->slavesMask; // Retest under lock protection + bool finished = this_sp->slavesMask.none(); // Retest under lock protection this_sp->mutex.unlock(); if (finished) return; @@ -1610,13 +1628,10 @@ void check_time() { sp.mutex.lock(); nodes += sp.nodes; - Bitboard sm = sp.slavesMask; - while (sm) - { - Position* pos = Threads[pop_lsb(&sm)]->activePosition; - if (pos) - nodes += pos->nodes_searched(); - } + + for (size_t idx = 0; idx < Threads.size(); ++idx) + if (sp.slavesMask.test(idx) && Threads[idx]->activePosition) + nodes += Threads[idx]->activePosition->nodes_searched(); sp.mutex.unlock(); } @@ -1627,8 +1642,7 @@ void check_time() { Time::point elapsed = Time::now() - SearchTime; bool stillAtFirstMove = Signals.firstRootMove && !Signals.failedLowAtRoot - && elapsed > TimeMgr.available_time() - && elapsed > IterationTime * 1.4; + && elapsed > TimeMgr.available_time() * 75 / 100; bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution || stillAtFirstMove;