X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=d94128eb41c944bd34ec5d92432aad714e5efce5;hp=6d05405b6f79c9ad002824bbafd0777b132f000b;hb=d85cf6d9c3fb31865d9b671d2475a6a81e84e070;hpb=706b44a966a6ea2fe9a1a7adaf28f7964eec3115 diff --git a/src/search.cpp b/src/search.cpp index 6d05405b..d94128eb 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -209,10 +209,6 @@ namespace { // Minimum depth for use of singular extension const Depth SingularExtensionDepth[2] = { 8 * ONE_PLY /* non-PV */, 6 * ONE_PLY /* PV */}; - // If the TT move is at least SingularExtensionMargin better than the - // remaining ones we will extend it. - const Value SingularExtensionMargin = Value(0x20); - // Step 12. Futility pruning // Futility margin for quiescence search @@ -302,11 +298,10 @@ namespace { void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount); void update_killers(Move m, Move killers[]); void update_gains(const Position& pos, Move move, Value before, Value after); - void qsearch_scoring(Position& pos, MoveStack* mlist, MoveStack* last); int current_search_time(); std::string value_to_uci(Value v); - int nps(const Position& pos); + std::string speed_to_uci(int64_t nodes); void poll(const Position& pos); void wait_for_stop_or_ponderhit(); @@ -558,14 +553,14 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[ Move bestMove = id_loop(pos, searchMoves, &ponderMove); // Print final search statistics - cout << "info nodes " << pos.nodes_searched() - << " nps " << nps(pos) - << " time " << current_search_time() << endl; + cout << "info" << speed_to_uci(pos.nodes_searched()) << endl; if (UseLogFile) { + int t = current_search_time(); + LogFile << "Nodes: " << pos.nodes_searched() - << "\nNodes/second: " << nps(pos) + << "\nNodes/second: " << (t > 0 ? int(pos.nodes_searched() * 1000 / t) : 0) << "\nBest move: " << move_to_san(pos, bestMove); StateInfo st; @@ -601,21 +596,21 @@ namespace { SearchStack ss[PLY_MAX_PLUS_2]; Value bestValues[PLY_MAX_PLUS_2]; int bestMoveChanges[PLY_MAX_PLUS_2]; - int depth, researchCountFL, researchCountFH, aspirationDelta; + int depth, aspirationDelta; Value value, alpha, beta; Move bestMove, easyMove; - // Moves to search are verified, scored and sorted - Rml.init(pos, searchMoves); - - // Initialize FIXME move before Rml.init() + // Initialize stuff before a new search + memset(ss, 0, 4 * sizeof(SearchStack)); TT.new_search(); H.clear(); - memset(ss, 0, 4 * sizeof(SearchStack)); *ponderMove = bestMove = easyMove = MOVE_NONE; depth = aspirationDelta = 0; - ss->currentMove = MOVE_NULL; // Hack to skip update_gains() alpha = -VALUE_INFINITE, beta = VALUE_INFINITE; + ss->currentMove = MOVE_NULL; // Hack to skip update_gains() + + // Moves to search are verified and copied + Rml.init(pos, searchMoves); // Handle special case of searching on a mate/stalemate position if (Rml.size() == 0) @@ -627,15 +622,10 @@ namespace { return MOVE_NONE; } - // Is one move significantly better than others after initial scoring ? - if ( Rml.size() == 1 - || Rml[0].pv_score > Rml[1].pv_score + EasyMoveMargin) - easyMove = Rml[0].pv[0]; - // Iterative deepening loop while (++depth <= PLY_MAX && (!MaxDepth || depth <= MaxDepth) && !StopRequest) { - Rml.bestMoveChanges = researchCountFL = researchCountFH = 0; + Rml.bestMoveChanges = 0; cout << "info depth " << depth << endl; // Calculate dynamic aspiration window based on previous iterations @@ -653,8 +643,7 @@ namespace { // Start with a small aspiration window and, in case of fail high/low, // research with bigger window until not failing high/low anymore. - while (true) - { + do { // Search starting from ss+1 to allow calling update_gains() value = search(pos, ss+1, alpha, beta, depth * ONE_PLY, 0); @@ -677,20 +666,21 @@ namespace { // otherwise exit the fail high/low loop. if (value >= beta) { - beta = Min(beta + aspirationDelta * (1 << researchCountFH), VALUE_INFINITE); - researchCountFH++; + beta = Min(beta + aspirationDelta, VALUE_INFINITE); + aspirationDelta += aspirationDelta / 2; } else if (value <= alpha) { AspirationFailLow = true; StopOnPonderhit = false; - alpha = Max(alpha - aspirationDelta * (1 << researchCountFL), -VALUE_INFINITE); - researchCountFL++; + 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]; @@ -700,8 +690,10 @@ namespace { if (UseLogFile) LogFile << pretty_pv(pos, depth, value, current_search_time(), Rml[0].pv) << endl; - // Drop the easy move if differs from the new best move - if (bestMove != easyMove) + // 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)) + easyMove = bestMove; + else if (bestMove != easyMove) easyMove = MOVE_NONE; if (UseTimeManagement && !StopRequest) @@ -1028,9 +1020,7 @@ split_point_start: // At split points actual search starts from here if (SendSearchedNodes) { SendSearchedNodes = false; - cout << "info nodes " << nodes - << " nps " << nps(pos) - << " time " << current_search_time() << endl; + cout << "info" << speed_to_uci(pos.nodes_searched()) << endl; } if (current_search_time() >= 1000) @@ -1038,7 +1028,9 @@ split_point_start: // At split points actual search starts from here << " currmovenumber " << moveCount << endl; } - isPvMove = (PvNode && moveCount <= (Root ? MultiPV : 1)); + // At Root and at first iteration do a PV search on all the moves + // to score root moves. Otherwise only the first one is the PV. + isPvMove = (PvNode && moveCount <= (Root ? MultiPV + 1000 * (depth <= ONE_PLY) : 1)); moveIsCheck = pos.move_is_check(move, ci); captureOrPromotion = pos.move_is_capture_or_promotion(move); @@ -1057,7 +1049,7 @@ split_point_start: // At split points actual search starts from here if (abs(ttValue) < VALUE_KNOWN_WIN) { - Value b = ttValue - SingularExtensionMargin; + Value b = ttValue - depth; ss->excludedMove = move; ss->skipNullMove = true; Value v = search(pos, ss, b - 1, b, depth / 2, ply); @@ -1433,6 +1425,12 @@ split_point_start: // At split points actual search starts from here bestValue = futilityValue; continue; } + + // Prune moves with negative or equal SEE + if ( futilityBase < beta + && depth < DEPTH_ZERO + && pos.see(move) <= 0) + continue; } // Detect non-capture evasions that are candidate to be pruned @@ -1501,26 +1499,6 @@ split_point_start: // At split points actual search starts from here } - // qsearch_scoring() scores each move of a list using a qsearch() evaluation, - // it is used in RootMoveList to get an initial scoring. - void qsearch_scoring(Position& pos, MoveStack* mlist, MoveStack* last) { - - SearchStack ss[PLY_MAX_PLUS_2]; - StateInfo st; - - memset(ss, 0, 4 * sizeof(SearchStack)); - ss[0].eval = ss[0].evalMargin = VALUE_NONE; - - for (MoveStack* cur = mlist; cur != last; cur++) - { - ss[0].currentMove = cur->move; - pos.do_move(cur->move, st); - cur->score = -qsearch(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, DEPTH_ZERO, 1); - pos.undo_move(cur->move); - } - } - - // check_is_dangerous() tests if a checking move can be pruned in qsearch(). // bestValue is updated only when returning false because in that case move // will be pruned. @@ -1858,6 +1836,14 @@ split_point_start: // At split points actual search starts from here H.update_gain(pos.piece_on(move_to(m)), move_to(m), -(before + after)); } + // current_search_time() returns the number of milliseconds which have passed + // since the beginning of the current search. + + int current_search_time() { + + return get_system_time() - SearchStartTime; + } + // value_to_uci() converts a value to a string suitable for use with the UCI // protocol specifications: @@ -1879,21 +1865,19 @@ split_point_start: // At split points actual search starts from here } - // current_search_time() returns the number of milliseconds which have passed - // since the beginning of the current search. - - int current_search_time() { - - return get_system_time() - SearchStartTime; - } + // speed_to_uci() returns a string with time stats of current search suitable + // to be sent to UCI gui. + std::string speed_to_uci(int64_t nodes) { - // nps() computes the current nodes/second count + std::stringstream s; + int t = current_search_time(); - int nps(const Position& pos) { + s << " nodes " << nodes + << " nps " << (t > 0 ? int(nodes * 1000 / t) : 0) + << " time " << t; - int t = current_search_time(); - return (t > 0 ? int((pos.nodes_searched() * 1000) / t) : 0); + return s.str(); } @@ -2538,9 +2522,7 @@ split_point_start: // At split points actual search starts from here << " multipv " << pvLine + 1 << " score " << value_to_uci(pv_score) << (pv_score >= beta ? " lowerbound" : pv_score <= alpha ? " upperbound" : "") - << " time " << current_search_time() - << " nodes " << pos.nodes_searched() - << " nps " << nps(pos) + << speed_to_uci(pos.nodes_searched()) << " pv " << l.str(); return s.str(); @@ -2555,11 +2537,8 @@ split_point_start: // At split points actual search starts from here clear(); bestMoveChanges = 0; - // Generate all legal moves and score them + // Generate all legal moves and add them to RootMoveList MoveStack* last = generate(pos, mlist); - qsearch_scoring(pos, mlist, last); - - // Add each move to the RootMoveList's vector for (MoveStack* cur = mlist; cur != last; cur++) { // If we have a searchMoves[] list then verify cur->move @@ -2572,10 +2551,9 @@ split_point_start: // At split points actual search starts from here RootMove rm; rm.pv[0] = cur->move; rm.pv[1] = MOVE_NONE; - rm.pv_score = Value(cur->score); + rm.pv_score = -VALUE_INFINITE; push_back(rm); } - sort(); } } // namespace