X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=5921ae0fd77a093c95b59e3c0c8f3a1b2d02bc04;hp=fce0409bf17023e89ad61665b4afcb5bc885df14;hb=c71ae794df257e3d6f1e925b6d013434bb2f99ef;hpb=ce619b3b6ceb96bbf1e90f8281fdc89b9e64ec5e diff --git a/src/search.cpp b/src/search.cpp index fce0409b..5921ae0f 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -52,38 +52,30 @@ namespace { enum NodeType { Root, PV, NonPV, SplitPointPV, SplitPointNonPV }; // RootMove struct is used for moves at the root of the tree. For each root - // move, we store two scores, a node count, and a PV (really a refutation + // move, we store a pv_score, a node count, and a PV (really a refutation // in the case of moves which fail low). Value pv_score is normally set at - // -VALUE_INFINITE for all non-pv moves, while non_pv_score is computed - // according to the order in which moves are returned by MovePicker. + // -VALUE_INFINITE for all non-pv moves. struct RootMove { - RootMove(); - RootMove(const RootMove& rm) { *this = rm; } - RootMove& operator=(const RootMove& rm); - // RootMove::operator<() is the comparison function used when // sorting the moves. A move m1 is considered to be better - // than a move m2 if it has an higher pv_score, or if it has - // equal pv_score but m1 has the higher non_pv_score. In this way - // we are guaranteed that PV moves are always sorted as first. - bool operator<(const RootMove& m) const { - return pv_score != m.pv_score ? pv_score < m.pv_score - : non_pv_score < m.non_pv_score; - } + // than a move m2 if it has an higher pv_score + bool operator<(const RootMove& m) const { return pv_score < m.pv_score; } void extract_pv_from_tt(Position& pos); void insert_pv_in_tt(Position& pos); int64_t nodes; Value pv_score; - Value non_pv_score; - Move pv[PLY_MAX_PLUS_2]; + std::vector pv; }; // RootMoveList struct is mainly a std::vector of RootMove objects struct RootMoveList : public std::vector { + void init(Position& pos, Move searchMoves[]); + RootMove* find(const Move& m, int startIndex = 0); + int bestMoveChanges; }; @@ -166,7 +158,7 @@ namespace { RootMoveList Rml; // MultiPV mode - int MultiPV, UCIMultiPV; + int MultiPV, UCIMultiPV, MultiPVIteration; // Time management variables bool StopOnPonderhit, FirstRootMove, StopRequest, QuitRequest, AspirationFailLow; @@ -212,9 +204,9 @@ namespace { void do_skill_level(Move* best, Move* ponder); int current_search_time(int set = 0); - string score_to_uci(Value v, Value alpha, Value beta); + string score_to_uci(Value v, Value alpha = -VALUE_INFINITE, Value beta = VALUE_INFINITE); string speed_to_uci(int64_t nodes); - string pv_to_uci(Move pv[], int pvNum, bool chess960); + string pv_to_uci(const Move pv[], int pvNum, bool chess960); string pretty_pv(Position& pos, int depth, Value score, int time, Move pv[]); string depth_to_uci(Depth depth); void poll(const Position& pos); @@ -227,15 +219,13 @@ namespace { MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) : MovePicker(p, ttm, d, h, ss, b) {} - - RootMove& current() { assert(false); return Rml[0]; } // Dummy, needed to compile }; // In case of a SpNode we use split point's shared MovePicker object as moves source - template<> struct MovePickerExt : public MovePickerExt { + template<> struct MovePickerExt : public MovePicker { MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) - : MovePickerExt(p, ttm, d, h, ss, b), mp(ss->sp->mp) {} + : MovePicker(p, ttm, d, h, ss, b), mp(ss->sp->mp) {} Move get_next_move() { return mp->get_next_move(); } MovePicker* mp; @@ -247,16 +237,6 @@ namespace { : MovePickerExt(p, ttm, d, h, ss, b) {} }; - // In case of a Root node we use RootMoveList as moves source - template<> struct MovePickerExt : public MovePicker { - - MovePickerExt(const Position&, Move, Depth, const History&, SearchStack*, Value); - RootMove& current() { return Rml[cur]; } - Move get_next_move() { return ++cur < (int)Rml.size() ? Rml[cur].pv[0] : MOVE_NONE; } - - int cur; - }; - // Overload operator<<() to make it easier to print moves in a coordinate // notation compatible with UCI protocol. std::ostream& operator<<(std::ostream& os, Move m) { @@ -536,7 +516,7 @@ namespace { H.clear(); *ponderMove = bestMove = easyMove = skillBest = skillPonder = MOVE_NONE; depth = aspirationDelta = 0; - alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; + value = alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; ss->currentMove = MOVE_NULL; // Hack to skip update_gains() // Moves to search are verified and copied @@ -554,65 +534,100 @@ namespace { // Iterative deepening loop until requested to stop or target depth reached while (!StopRequest && ++depth <= PLY_MAX && (!Limits.maxDepth || depth <= Limits.maxDepth)) { + // Remember best moves and values from previous iteration + RootMoveList prevRml = Rml; + Rml.bestMoveChanges = 0; - // Calculate dynamic aspiration window based on previous iterations - if (MultiPV == 1 && depth >= 5 && abs(bestValues[depth - 1]) < VALUE_KNOWN_WIN) + // MultiPV iteration loop + for (MultiPVIteration = 0; MultiPVIteration < Min(MultiPV, (int)Rml.size()); MultiPVIteration++) { - int prevDelta1 = bestValues[depth - 1] - bestValues[depth - 2]; - int prevDelta2 = bestValues[depth - 2] - bestValues[depth - 3]; - - aspirationDelta = Min(Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24); - aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize + // Calculate dynamic aspiration window based on previous iterations + if (depth >= 5 && abs(prevRml[MultiPVIteration].pv_score) < VALUE_KNOWN_WIN) + { + int prevDelta1 = bestValues[depth - 1] - bestValues[depth - 2]; + int prevDelta2 = bestValues[depth - 2] - bestValues[depth - 3]; - alpha = Max(bestValues[depth - 1] - aspirationDelta, -VALUE_INFINITE); - beta = Min(bestValues[depth - 1] + aspirationDelta, VALUE_INFINITE); - } + aspirationDelta = Min(Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24); + aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize - // Start with a small aspiration window and, in case of fail high/low, - // research with bigger window until not failing high/low anymore. - do { - // Search starting from ss+1 to allow calling update_gains() - value = search(pos, ss+1, alpha, beta, depth * ONE_PLY); - - // Write PV back to transposition table in case the relevant entries - // have been overwritten during the search. - for (int i = 0; i < Min(MultiPV, (int)Rml.size()); i++) - Rml[i].insert_pv_in_tt(pos); - - // Value cannot be trusted. Break out immediately! - if (StopRequest) - break; - - // 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 ((value > alpha && value < beta) || current_search_time() > 2000) - for (int i = 0; i < Min(UCIMultiPV, (int)Rml.size()); i++) - cout << "info" - << depth_to_uci(depth * ONE_PLY) - << score_to_uci(Rml[i].pv_score, alpha, beta) - << speed_to_uci(pos.nodes_searched()) - << pv_to_uci(Rml[i].pv, i + 1, pos.is_chess960()) << endl; - - // In case of failing high/low increase aspiration window and research, - // otherwise exit the fail high/low loop. - if (value >= beta) - { - beta = Min(beta + aspirationDelta, VALUE_INFINITE); - aspirationDelta += aspirationDelta / 2; + alpha = Max(prevRml[MultiPVIteration].pv_score - aspirationDelta, -VALUE_INFINITE); + beta = Min(prevRml[MultiPVIteration].pv_score + aspirationDelta, VALUE_INFINITE); } - else if (value <= alpha) + else { - AspirationFailLow = true; - StopOnPonderhit = false; - - alpha = Max(alpha - aspirationDelta, -VALUE_INFINITE); - aspirationDelta += aspirationDelta / 2; + alpha = -VALUE_INFINITE; + beta = VALUE_INFINITE; } - else - break; - } while (abs(value) < VALUE_KNOWN_WIN); + // Start with a small aspiration window and, in case of fail high/low, + // research with bigger window until not failing high/low anymore. + do { + // Search starting from ss+1 to allow calling update_gains() + value = search(pos, ss+1, alpha, beta, depth * ONE_PLY); + + // It is critical that sorting is done with a stable algorithm + // because all the values but the first are usually set to + // -VALUE_INFINITE and we want to keep the same order for all + // the moves but the new PV that goes to head. + sort(Rml.begin() + MultiPVIteration, Rml.end()); + + // In case we have found an exact score reorder the PV moves + // before leaving the fail high/low loop, otherwise leave the + // last PV move in its position so to be searched again. + if (value > alpha && value < beta) + sort(Rml.begin(), Rml.begin() + MultiPVIteration); + + // Write PV back to transposition table in case the relevant entries + // have been overwritten during the search. + for (int i = 0; i <= MultiPVIteration; i++) + Rml[i].insert_pv_in_tt(pos); + + // Value cannot be trusted. Break out immediately! + if (StopRequest) + break; + + // 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 ((value > alpha && value < beta) || current_search_time() > 2000) + for (int i = 0; i < Min(UCIMultiPV, (int)Rml.size()); i++) + { + bool updated = (i <= MultiPVIteration); + + if (depth == 1 && !updated) + continue; + + const RootMoveList& rml = (updated ? Rml : prevRml); + + cout << "info" + << depth_to_uci((updated ? depth : depth - 1) * ONE_PLY) + << (i == MultiPVIteration ? score_to_uci(rml[i].pv_score, alpha, beta) + : score_to_uci(rml[i].pv_score)) + << speed_to_uci(pos.nodes_searched()) + << pv_to_uci(&rml[i].pv[0], i + 1, pos.is_chess960()) + << endl; + } + + // In case of failing high/low increase aspiration window and research, + // otherwise exit the fail high/low loop. + if (value >= beta) + { + beta = Min(beta + aspirationDelta, VALUE_INFINITE); + aspirationDelta += aspirationDelta / 2; + } + else if (value <= alpha) + { + AspirationFailLow = true; + StopOnPonderhit = false; + + alpha = Max(alpha - aspirationDelta, -VALUE_INFINITE); + aspirationDelta += aspirationDelta / 2; + } + else + break; + + } while (abs(value) < VALUE_KNOWN_WIN); + } // Collect info about search result bestMove = Rml[0].pv[0]; @@ -625,7 +640,7 @@ namespace { do_skill_level(&skillBest, &skillPonder); if (LogFile.is_open()) - LogFile << pretty_pv(pos, depth, value, current_search_time(), Rml[0].pv) << endl; + LogFile << pretty_pv(pos, depth, value, current_search_time(), &Rml[0].pv[0]) << endl; // Init easyMove after first iteration or drop if differs from the best move if (depth == 1 && (Rml.size() == 1 || Rml[0].pv_score > Rml[1].pv_score + EasyMoveMargin)) @@ -937,7 +952,7 @@ namespace { split_point_start: // At split points actual search starts from here // Initialize a MovePicker object for the current position - MovePickerExt mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); + MovePickerExt mp(pos, RootNode ? Rml[MultiPVIteration].pv[0] : ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); CheckInfo ci(pos); ss->bestMove = MOVE_NONE; futilityBase = ss->eval + ss->evalMargin; @@ -965,6 +980,12 @@ split_point_start: // At split points actual search starts from here if (move == excludedMove) continue; + // At root obey the "searchmoves" option and skip moves not listed in Root Move List. + // Also in MultiPV mode we skip moves which already have got an exact score + // in previous MultiPV Iteration. + if (RootNode && !Rml.find(move, MultiPVIteration)) + 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)) continue; @@ -996,11 +1017,11 @@ split_point_start: // At split points actual search starts from here // For long searches send current move info to GUI if (current_search_time() > 2000) cout << "info" << depth_to_uci(depth) - << " currmove " << move << " currmovenumber " << moveCount << endl; + << " currmove " << move << " currmovenumber " << moveCount + MultiPVIteration << endl; } // At Root and at first iteration do a PV search on all the moves to score root moves - isPvMove = (PvNode && moveCount <= (!RootNode ? 1 : depth <= ONE_PLY ? MAX_MOVES : MultiPV)); + isPvMove = (PvNode && moveCount <= ((RootNode && depth <= ONE_PLY) ? MAX_MOVES : 1)); givesCheck = pos.move_gives_check(move, ci); captureOrPromotion = pos.move_is_capture_or_promotion(move); @@ -1191,14 +1212,15 @@ split_point_start: // At split points actual search starts from here break; // Remember searched nodes counts for this move - mp.current().nodes += pos.nodes_searched() - nodes; + RootMove* rm = Rml.find(move); + rm->nodes += pos.nodes_searched() - nodes; // PV move or new best move ? if (isPvMove || value > alpha) { // Update PV - mp.current().pv_score = value; - mp.current().extract_pv_from_tt(pos); + rm->pv_score = value; + rm->extract_pv_from_tt(pos); // We record how often the best move has been changed in each // iteration. This information is used for time management: When @@ -1206,24 +1228,15 @@ split_point_start: // At split points actual search starts from here if (!isPvMove && MultiPV == 1) Rml.bestMoveChanges++; - // It is critical that sorting is done with a stable algorithm - // because all the values but the first are usually set to - // -VALUE_INFINITE and we want to keep the same order for all - // the moves but the new PV that goes to head. - sort(Rml.begin(), Rml.begin() + moveCount); - - // Update alpha. In multi-pv we don't use aspiration window, so set - // alpha equal to minimum score among the PV lines searched so far. - if (MultiPV > 1) - alpha = Rml[Min(moveCount, MultiPV) - 1].pv_score; - else if (value > alpha) + // Update alpha. + if (value > alpha) alpha = value; } else // All other moves but the PV are set to the lowest value, this // is not a problem when sorting becuase sort is stable and move // position in the list is preserved, just the PV is pushed up. - mp.current().pv_score = -VALUE_INFINITE; + rm->pv_score = -VALUE_INFINITE; } // RootNode @@ -1782,7 +1795,7 @@ split_point_start: // At split points actual search starts from here // pv_to_uci() returns a string with information on the current PV line // formatted according to UCI specification. - string pv_to_uci(Move pv[], int pvNum, bool chess960) { + string pv_to_uci(const Move pv[], int pvNum, bool chess960) { std::stringstream s; @@ -2041,27 +2054,6 @@ split_point_start: // At split points actual search starts from here /// RootMove and RootMoveList method's definitions - RootMove::RootMove() { - - nodes = 0; - pv_score = non_pv_score = -VALUE_INFINITE; - pv[0] = MOVE_NONE; - } - - RootMove& RootMove::operator=(const RootMove& rm) { - - const Move* src = rm.pv; - Move* dst = pv; - - // Avoid a costly full rm.pv[] copy - do *dst++ = *src; while (*src++ != MOVE_NONE); - - nodes = rm.nodes; - pv_score = rm.pv_score; - non_pv_score = rm.non_pv_score; - return *this; - } - void RootMoveList::init(Position& pos, Move searchMoves[]) { Move* sm; @@ -2079,13 +2071,23 @@ split_point_start: // At split points actual search starts from here continue; RootMove rm; - rm.pv[0] = ml.move(); - rm.pv[1] = MOVE_NONE; + rm.pv.push_back(ml.move()); + rm.pv.push_back(MOVE_NONE); rm.pv_score = -VALUE_INFINITE; + rm.nodes = 0; push_back(rm); } } + RootMove* RootMoveList::find(const Move& m, int startIndex) { + + for (size_t i = startIndex; i < size(); i++) + if ((*this)[i].pv[0] == m) + return &(*this)[i]; + + return NULL; + } + // extract_pv_from_tt() builds a PV by adding moves from the transposition table. // We consider also failing high nodes and not only VALUE_TYPE_EXACT nodes. This // allow to always have a ponder move even when we fail high at root and also a @@ -2096,10 +2098,13 @@ split_point_start: // At split points actual search starts from here StateInfo state[PLY_MAX_PLUS_2], *st = state; TTEntry* tte; int ply = 1; + Move m = pv[0]; - assert(pv[0] != MOVE_NONE && pos.move_is_pl(pv[0])); + assert(m != MOVE_NONE && pos.move_is_pl(m)); - pos.do_move(pv[0], *st++); + pv.clear(); + pv.push_back(m); + pos.do_move(m, *st++); while ( (tte = TT.probe(pos.get_key())) != NULL && tte->move() != MOVE_NONE @@ -2108,10 +2113,11 @@ split_point_start: // At split points actual search starts from here && ply < PLY_MAX && (!pos.is_draw() || ply < 2)) { - pv[ply] = tte->move(); - pos.do_move(pv[ply++], *st++); + pv.push_back(tte->move()); + pos.do_move(tte->move(), *st++); + ply++; } - pv[ply] = MOVE_NONE; + pv.push_back(MOVE_NONE); do pos.undo_move(pv[--ply]); while (ply); } @@ -2146,29 +2152,6 @@ split_point_start: // At split points actual search starts from here do pos.undo_move(pv[--ply]); while (ply); } - - // Specializations for MovePickerExt in case of Root node - MovePickerExt::MovePickerExt(const Position& p, Move ttm, Depth d, - const History& h, SearchStack* ss, Value b) - : MovePicker(p, ttm, d, h, ss, b), cur(-1) { - Move move; - Value score = VALUE_ZERO; - - // Score root moves using standard ordering used in main search, the moves - // are scored according to the order in which they are returned by MovePicker. - // This is the second order score that is used to compare the moves when - // the first orders pv_score of both moves are equal. - while ((move = MovePicker::get_next_move()) != MOVE_NONE) - for (RootMoveList::iterator rm = Rml.begin(); rm != Rml.end(); ++rm) - if (rm->pv[0] == move) - { - rm->non_pv_score = score--; - break; - } - - sort(Rml.begin(), Rml.end()); - } - } // namespace