X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=7ff9aaa466902ae5b851ea2c225a853d8416c576;hp=9a373dec456223cfbac60cd4ce8729adbf3d7a13;hb=05c6f7a40b62f286873945f937c2ef3cae183e41;hpb=ccad6013892a95574e7c3ec652f3e03c357d10b7 diff --git a/src/search.cpp b/src/search.cpp index 9a373dec..7ff9aaa4 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -44,7 +44,6 @@ namespace Search { Color RootColor; Time::point SearchTime; StateStackPtr SetupStates; - MovesVectPtr SetupMoves; } using std::string; @@ -87,8 +86,9 @@ namespace { TimeManager TimeMgr; int BestMoveChanges; Value DrawValue[COLOR_NB]; - History Hist; - Gains Gain; + HistoryStats History; + GainsStats Gains; + CountermovesStats Countermoves; template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth); @@ -146,7 +146,7 @@ void Search::init() { // Init futility move count array for (d = 0; d < 32; d++) - FutilityMoveCounts[d] = int(3.001 + 0.25 * pow(double(d), 2.0)); + FutilityMoveCounts[d] = int(3.001 + 0.3 * pow(double(d), 1.8)); } @@ -163,11 +163,11 @@ size_t Search::perft(Position& pos, Depth depth) { size_t cnt = 0; CheckInfo ci(pos); - for (MoveList ml(pos); !ml.end(); ++ml) + for (MoveList it(pos); *it; ++it) { - pos.do_move(ml.move(), st, ci, pos.move_gives_check(ml.move(), ci)); + pos.do_move(*it, st, ci, pos.move_gives_check(*it, ci)); cnt += perft(pos, depth - ONE_PLY); - pos.undo_move(ml.move()); + pos.undo_move(*it); } return cnt; @@ -265,6 +265,10 @@ void Search::think() { finalize: + // When search is stopped this info is not printed + sync_cout << "info nodes " << RootPos.nodes_searched() + << " time " << Time::now() - SearchTime + 1 << sync_endl; + // When we reach max depth we arrive here even without Signals.stop is raised, // but if we are pondering or in infinite search, according to UCI protocol, // we shouldn't print the best move before the GUI sends a "stop" or "ponderhit" @@ -294,15 +298,15 @@ namespace { Stack ss[MAX_PLY_PLUS_2]; int depth, prevBestMoveChanges; Value bestValue, alpha, beta, delta; - bool bestMoveNeverChanged = true; memset(ss, 0, 4 * sizeof(Stack)); depth = BestMoveChanges = 0; bestValue = delta = -VALUE_INFINITE; ss->currentMove = MOVE_NULL; // Hack to skip update gains TT.new_search(); - Hist.clear(); - Gain.clear(); + History.clear(); + Gains.clear(); + Countermoves.clear(); PVSize = Options["MultiPV"]; Skill skill(Options["Skill Level"]); @@ -412,15 +416,15 @@ namespace { if (Options["Use Search Log"]) { + RootMove& rm = RootMoves[0]; + if (skill.best != MOVE_NONE) + rm = *std::find(RootMoves.begin(), RootMoves.end(), skill.best); + Log log(Options["Search Log Filename"]); - log << pretty_pv(pos, depth, bestValue, Time::now() - SearchTime, &RootMoves[0].pv[0]) + log << pretty_pv(pos, depth, rm.score, Time::now() - SearchTime, rm.pv.data()) << std::endl; } - // Filter out startup noise when monitoring best move stability - if (depth > 2 && BestMoveChanges) - bestMoveNeverChanged = false; - // Do we have found a "mate in x"? if ( Limits.mate && bestValue >= VALUE_MATE_IN_MAX_PLY @@ -442,18 +446,13 @@ namespace { if (Time::now() - SearchTime > (TimeMgr.available_time() * 62) / 100) stop = true; - bool recapture = pos.is_capture(RootMoves[0].pv[0]) - && pos.captured_piece_type() - && SetupMoves->size() - && to_sq(SetupMoves->back()) == to_sq(RootMoves[0].pv[0]); - // Stop search early if one move seems to be much better than others if ( depth >= 12 && !stop && PVSize == 1 - && ( (bestMoveNeverChanged && recapture) - || RootMoves.size() == 1 - || Time::now() - SearchTime > (TimeMgr.available_time() * 40) / 100)) + && bestValue > VALUE_MATED_IN_MAX_PLY + && ( RootMoves.size() == 1 + || Time::now() - SearchTime > (TimeMgr.available_time() * 20) / 100)) { Value rBeta = bestValue - 2 * PawnValueMg; (ss+1)->excludedMove = RootMoves[0].pv[0]; @@ -534,6 +533,7 @@ namespace { bestValue = -VALUE_INFINITE; ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; ss->ply = (ss-1)->ply + 1; + ss->futilityMoveCount = 0; (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; @@ -544,7 +544,7 @@ 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 || 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 @@ -627,7 +627,7 @@ namespace { && type_of(move) == NORMAL) { Square to = to_sq(move); - Gain.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); + Gains.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); } // Step 6. Razoring (is omitted in PV nodes) @@ -654,10 +654,11 @@ namespace { && !ss->skipNullMove && depth < 4 * ONE_PLY && !inCheck - && eval - FutilityMargins[depth][0] >= beta + && eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta && abs(beta) < VALUE_MATE_IN_MAX_PLY + && abs(eval) < VALUE_KNOWN_WIN && pos.non_pawn_material(pos.side_to_move())) - return eval - FutilityMargins[depth][0]; + return eval - futility_margin(depth, (ss-1)->futilityMoveCount); // Step 8. Null move search with verification search (is omitted in PV nodes) if ( !PvNode @@ -690,7 +691,7 @@ namespace { if (nullValue >= VALUE_MATE_IN_MAX_PLY) nullValue = beta; - if (depth < 6 * ONE_PLY) + if (depth < 12 * ONE_PLY) return nullValue; // Do verification search at high depths @@ -737,7 +738,7 @@ namespace { assert((ss-1)->currentMove != MOVE_NONE); assert((ss-1)->currentMove != MOVE_NULL); - MovePicker mp(pos, ttMove, Hist, pos.captured_piece_type()); + MovePicker mp(pos, ttMove, History, pos.captured_piece_type()); CheckInfo ci(pos); while ((move = mp.next_move()) != MOVE_NONE) @@ -757,7 +758,7 @@ namespace { && ttMove == MOVE_NONE && (PvNode || (!inCheck && ss->staticEval + Value(256) >= beta))) { - Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2); + Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4); ss->skipNullMove = true; search(pos, ss, alpha, beta, d); @@ -769,7 +770,11 @@ namespace { split_point_start: // At split points actual search starts from here - MovePicker mp(pos, ttMove, depth, Hist, ss, PvNode ? -VALUE_INFINITE : beta); + Square prevMoveSq = to_sq((ss-1)->currentMove); + Move countermoves[] = { Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].first, + Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].second }; + + MovePicker mp(pos, ttMove, depth, History, countermoves, ss, PvNode ? -VALUE_INFINITE : beta); CheckInfo ci(pos); value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc singularExtensionNode = !RootNode @@ -864,14 +869,15 @@ split_point_start: // At split points actual search starts from here newDepth = depth - ONE_PLY + ext; // Step 13. Futility pruning (is omitted in PV nodes) - if ( !captureOrPromotion + if ( !PvNode + && !captureOrPromotion && !inCheck && !dangerous - && move != ttMove) + /* && move != ttMove Already implicit in the next condition */ + && bestValue > VALUE_MATED_IN_MAX_PLY) { // Move count based pruning - if ( !PvNode - && depth < 16 * ONE_PLY + if ( depth < 16 * ONE_PLY && moveCount >= FutilityMoveCounts[depth] && (!threatMove || !refutes(pos, move, threatMove))) { @@ -886,18 +892,23 @@ split_point_start: // At split points actual search starts from here // but fixing this made program slightly weaker. Depth predictedDepth = newDepth - reduction(depth, moveCount); futilityValue = ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount) - + Gain[pos.piece_moved(move)][to_sq(move)]; + + Gains[pos.piece_moved(move)][to_sq(move)]; - if (!PvNode && futilityValue < beta) + if (futilityValue < beta) { + bestValue = std::max(bestValue, futilityValue); + if (SpNode) + { splitPoint->mutex.lock(); - + if (bestValue > splitPoint->bestValue) + splitPoint->bestValue = bestValue; + } continue; } // Prune moves with negative SEE at low depths - if ( predictedDepth < 2 * ONE_PLY + if ( predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < 0) { if (SpNode) @@ -905,7 +916,13 @@ split_point_start: // At split points actual search starts from here continue; } + + // We have not pruned the move that will be searched, but remember how + // far in the move list we are to be more aggressive in the child node. + ss->futilityMoveCount = moveCount; } + else + ss->futilityMoveCount = 0; // Check for legality only before to do the move if (!RootNode && !SpNode && !pos.pl_move_is_legal(move, ci.pinned)) @@ -933,6 +950,9 @@ split_point_start: // At split points actual search starts from here && move != ss->killers[1]) { ss->reduction = reduction(depth, moveCount); + if (move == countermoves[0] || move == countermoves[1]) + ss->reduction = std::max(DEPTH_ZERO, ss->reduction-ONE_PLY); + Depth d = std::max(newDepth - ss->reduction, ONE_PLY); if (SpNode) alpha = splitPoint->alpha; @@ -1082,13 +1102,15 @@ split_point_start: // At split points actual search starts from here // Increase history value of the cut-off move Value bonus = Value(int(depth) * int(depth)); - Hist.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus); + History.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus); + if (is_ok((ss-1)->currentMove)) + Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, bestMove); // Decrease history of all the other played non-capture moves for (int i = 0; i < playedMoveCount - 1; i++) { Move m = movesSearched[i]; - Hist.update(pos.piece_moved(m), to_sq(m), -bonus); + History.update(pos.piece_moved(m), to_sq(m), -bonus); } } } @@ -1134,9 +1156,15 @@ 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()]; + // 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. + 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. posKey = pos.key(); @@ -1144,11 +1172,6 @@ split_point_start: // At split points actual search starts from here 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. - ttDepth = InCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS - : DEPTH_QS_NO_CHECKS; if ( tte && tte->depth() >= ttDepth && ttValue != VALUE_NONE // Only in case of TT access race @@ -1200,7 +1223,7 @@ split_point_start: // At split points actual search starts from here // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will // be generated. - MovePicker mp(pos, ttMove, depth, Hist, to_sq((ss-1)->currentMove)); + MovePicker mp(pos, ttMove, depth, History, to_sq((ss-1)->currentMove)); CheckInfo ci(pos); // Loop through the moves until no moves remain or a beta cutoff occurs @@ -1229,10 +1252,10 @@ split_point_start: // At split points actual search starts from here continue; } - // Prune moves with negative or equal SEE + // Prune moves with negative or equal SEE and also moves with positive + // SEE where capturing piece loses a tempo and SEE < beta - futilityBase. if ( futilityBase < beta - && depth < DEPTH_ZERO - && pos.see(move) <= 0) + && pos.see(move, beta - futilityBase) <= 0) { bestValue = std::max(bestValue, futilityBase); continue; @@ -1582,7 +1605,7 @@ void RootMove::extract_pv_from_tt(Position& pos) { && pos.is_pseudo_legal(m = tte->move()) // Local copy, TT could change && 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(MOVE_NONE); // Must be zero-terminating