X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=216964ab43d5434678695f1f9c88d076cb084243;hp=0b57c1fe3e7b35747a48bf659dd6d6f25365d8a0;hb=56273fca1edc51ffa0efc73715609f428c000c97;hpb=2f5aaf7de670b489e6a9635ae22713ed48e9f156 diff --git a/src/search.cpp b/src/search.cpp index 0b57c1fe..216964ab 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -43,8 +43,9 @@ namespace Search { std::vector RootMoves; Position RootPos; Color RootColor; - Time::point SearchTime, IterationTime; + Time::point SearchTime; StateStackPtr SetupStates; + Value Contempt[2]; // [bestValue > VALUE_DRAW] } using std::string; @@ -77,7 +78,7 @@ 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]; @@ -127,7 +128,7 @@ 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); @@ -145,8 +146,8 @@ 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)); } } @@ -154,10 +155,10 @@ 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. -static size_t perft(Position& pos, Depth depth) { +static uint64_t perft(Position& pos, Depth depth) { StateInfo st; - size_t cnt = 0; + uint64_t cnt = 0; CheckInfo ci(pos); const bool leaf = depth == 2 * ONE_PLY; @@ -170,7 +171,7 @@ static size_t perft(Position& pos, Depth depth) { return cnt; } -size_t Search::perft(Position& pos, Depth depth) { +uint64_t Search::perft(Position& pos, Depth depth) { return depth > ONE_PLY ? ::perft(pos, depth) : MoveList(pos).size(); } @@ -185,6 +186,10 @@ void Search::think() { RootColor = RootPos.side_to_move(); TimeMgr.init(Limits, RootPos.game_ply(), RootColor); + DrawValue[0] = DrawValue[1] = VALUE_DRAW; + Contempt[0] = Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns + Contempt[1] = (Options["Contempt Factor"] + 12) * PawnValueEg / 100; + if (RootMoves.empty()) { RootMoves.push_back(MOVE_NONE); @@ -206,16 +211,6 @@ void Search::think() { } } - 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"]); @@ -225,7 +220,7 @@ void Search::think() { << " time: " << Limits.time[RootColor] << " increment: " << Limits.inc[RootColor] << " moves to go: " << Limits.movestogo - << std::endl; + << "\n" << std::endl; } // Reset the threads, still sleeping: will wake up at split time @@ -306,21 +301,21 @@ 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)) { // Age out PV variability metric - BestMoveChanges *= 0.8; + BestMoveChanges *= 0.5; // Save the last iteration's scores before first PV line is searched and // all the move scores except the (new) PV are set to -VALUE_INFINITE. @@ -328,7 +323,7 @@ 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) @@ -345,6 +340,9 @@ namespace { { bestValue = search(pos, ss, alpha, beta, depth * ONE_PLY, false); + DrawValue[ RootColor] = VALUE_DRAW - Contempt[bestValue > VALUE_DRAW]; + DrawValue[~RootColor] = VALUE_DRAW + Contempt[bestValue > VALUE_DRAW]; + // Bring the best move to the front. It is critical that sorting // is done with a stable algorithm because all the values but the // first and eventually the new best one are set to -VALUE_INFINITE @@ -393,12 +391,10 @@ 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(); @@ -423,20 +419,14 @@ 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 most - // of the available time has been used. We probably don't have - // enough time to search the first move at the next iteration anyway. + // 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() * 62) / 100) - 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". @@ -464,7 +454,7 @@ namespace { const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV || NT == SplitPointRoot); const bool RootNode = (NT == Root || NT == SplitPointRoot); - 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); @@ -513,7 +503,7 @@ namespace { { // Step 2. Check for aborted search and immediate draw if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) - return DrawValue[pos.side_to_move()]; + return ss->ply > MAX_PLY && !inCheck ? evaluate(pos) : DrawValue[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 @@ -548,7 +538,6 @@ 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 @@ -640,8 +629,24 @@ namespace { (ss+1)->skipNullMove = false; pos.undo_null_move(); - if (nullValue >= beta) // Do not return unproven mate scores - return nullValue >= VALUE_MATE_IN_MAX_PLY ? beta : nullValue; + if (nullValue >= beta) + { + // Do not return unproven mate scores + if (nullValue >= VALUE_MATE_IN_MAX_PLY) + nullValue = beta; + + if (depth < 12 * ONE_PLY) + 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); + ss->skipNullMove = false; + + if (v >= beta) + return nullValue; + } } // Step 9. ProbCut (skipped when in check) @@ -653,8 +658,8 @@ 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); @@ -676,8 +681,8 @@ namespace { } // Step 10. Internal iterative deepening (skipped when in check) - if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY) - && ttMove == MOVE_NONE + if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY) + && !ttMove && (PvNode || ss->staticEval + Value(256) >= beta)) { Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4); @@ -764,7 +769,7 @@ 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 @@ -835,7 +840,7 @@ 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(); @@ -1007,7 +1012,7 @@ moves_loop: // When in check and at SpNode search starts from here // 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. + // A split node has at least one move - the one tried before to be split. if (!moveCount) return excludedMove ? alpha : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; @@ -1063,7 +1068,7 @@ moves_loop: // When in check and at SpNode search starts from here // Check for an instant draw or if the maximum ply has been reached if (pos.is_draw() || ss->ply > MAX_PLY) - return DrawValue[pos.side_to_move()]; + return ss->ply > MAX_PLY && !InCheck ? evaluate(pos) : DrawValue[pos.side_to_move()]; // 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 @@ -1160,7 +1165,7 @@ 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; @@ -1178,7 +1183,7 @@ 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 @@ -1305,7 +1310,7 @@ 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; @@ -1313,7 +1318,7 @@ 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; @@ -1341,7 +1346,7 @@ 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; @@ -1360,23 +1365,23 @@ 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 @@ -1468,7 +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; @@ -1527,14 +1532,14 @@ void Thread::idle_loop() { searching = false; activePosition = NULL; - sp->slavesMask &= ~(1ULL << idx); + sp->slavesMask.reset(idx); 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) + && sp->slavesMask.none()) { assert(!sp->masterThread->searching); sp->masterThread->notify_one(); @@ -1549,10 +1554,10 @@ void Thread::idle_loop() { // 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; @@ -1595,13 +1600,10 @@ 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(); } @@ -1612,9 +1614,7 @@ void check_time() { Time::point elapsed = Time::now() - SearchTime; bool stillAtFirstMove = Signals.firstRootMove && !Signals.failedLowAtRoot - && ( elapsed > TimeMgr.available_time() - || ( elapsed > (TimeMgr.available_time() * 62) / 100 - && elapsed > IterationTime * 1.4)); + && elapsed > TimeMgr.available_time() * 75 / 100; bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution || stillAtFirstMove;