X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=915e1af25d69ccee4e5faead5f68cf58b14ecd96;hp=b0d359d1955ee4f707c427207c8b2852499135f9;hb=ce2845d3334520d07e38750ff481212f092a3ceb;hpb=5815718177817de90f98513b776bc04376440f0a diff --git a/src/search.cpp b/src/search.cpp index b0d359d1..915e1af2 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; @@ -605,13 +600,13 @@ namespace { Value value, alpha, beta; Move bestMove, easyMove; - // Moves to search are verified, scored and sorted + // Moves to search are verified and copied Rml.init(pos, searchMoves); // Initialize FIXME move before Rml.init() TT.new_search(); H.clear(); - memset(ss, 0, PLY_MAX_PLUS_2 * sizeof(SearchStack)); + memset(ss, 0, 4 * sizeof(SearchStack)); *ponderMove = bestMove = easyMove = MOVE_NONE; depth = aspirationDelta = 0; ss->currentMove = MOVE_NULL; // Hack to skip update_gains() @@ -627,11 +622,6 @@ 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) { @@ -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) @@ -801,7 +793,8 @@ namespace { bestValue = alpha; // Step 1. Initialize node and poll. Polling can abort search - ss->currentMove = ss->bestMove = threatMove = MOVE_NONE; + ss->currentMove = ss->bestMove = threatMove = (ss+1)->excludedMove = MOVE_NONE; + (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; (ss+2)->killers[0] = (ss+2)->killers[1] = (ss+2)->mateKiller = MOVE_NONE; if (threadID == 0 && ++NodesSincePoll > NodesBetweenPolls) @@ -1027,9 +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) @@ -1037,7 +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); @@ -1056,7 +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); @@ -1070,7 +1063,7 @@ split_point_start: // At split points actual search starts from here // Update current move (this must be done after singular extension search) ss->currentMove = move; - newDepth = depth - (!Root ? ONE_PLY : DEPTH_ZERO) + ext; + newDepth = depth - ONE_PLY + ext; // Step 12. Futility pruning (is omitted in PV nodes) if ( !PvNode @@ -1192,14 +1185,14 @@ split_point_start: // At split points actual search starts from here alpha = sp->alpha; } - if (!Root && value > bestValue && !(SpNode && ThreadsMgr.cutoff_at_splitpoint(threadID))) + if (value > bestValue && !(SpNode && ThreadsMgr.cutoff_at_splitpoint(threadID))) { bestValue = value; if (SpNode) sp->bestValue = value; - if (value > alpha) + if (!Root && value > alpha) { if (PvNode && value < beta) // We want always alpha < beta { @@ -1217,16 +1210,12 @@ split_point_start: // At split points actual search starts from here ss->bestMove = move; if (SpNode) - sp->parentSstack->bestMove = move; + sp->ss->bestMove = move; } } if (Root) { - // To avoid to exit with bestValue == -VALUE_INFINITE - if (value > bestValue) - bestValue = value; - // Finished searching the move. If StopRequest 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 @@ -1238,13 +1227,9 @@ split_point_start: // At split points actual search starts from here // Remember searched nodes counts for this move mp.rm->nodes += pos.nodes_searched() - nodes; - // Step 17. Check for new best move - if (!isPvMove && value <= alpha) - mp.rm->pv_score = -VALUE_INFINITE; - else + // PV move or new best move ? + if (isPvMove || value > alpha) { - // PV move or new best move! - // Update PV ss->bestMove = move; mp.rm->pv_score = value; @@ -1264,9 +1249,11 @@ split_point_start: // At split points actual search starts from here alpha = Rml[Min(moveCount, MultiPV) - 1].pv_score; // FIXME why moveCount? else if (value > alpha) alpha = value; + } + else + mp.rm->pv_score = -VALUE_INFINITE; - } // PV move or new best move - } + } // Root // Step 18. Check for split if ( !Root @@ -1438,6 +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 @@ -1506,26 +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. @@ -1863,6 +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: @@ -1884,21 +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(); } @@ -2115,16 +2094,19 @@ split_point_start: // At split points actual search starts from here threads[threadID].state = THREAD_SEARCHING; - // Here we call search() with SplitPoint template parameter set to true + // Copy SplitPoint position and search stack and call search() + // with SplitPoint template parameter set to true. + SearchStack ss[PLY_MAX_PLUS_2]; SplitPoint* tsp = threads[threadID].splitPoint; Position pos(*tsp->pos, threadID); - SearchStack* ss = tsp->sstack[threadID] + 1; - ss->sp = tsp; + + memcpy(ss, tsp->ss - 1, 4 * sizeof(SearchStack)); + (ss+1)->sp = tsp; if (tsp->pvNode) - search(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); + search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); else - search(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); + search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); assert(threads[threadID].state == THREAD_SEARCHING); @@ -2369,7 +2351,7 @@ split_point_start: // At split points actual search starts from here splitPoint.moveCount = moveCount; splitPoint.pos = &pos; splitPoint.nodes = 0; - splitPoint.parentSstack = ss; + splitPoint.ss = ss; for (i = 0; i < activeThreads; i++) splitPoint.slaves[i] = 0; @@ -2396,12 +2378,10 @@ split_point_start: // At split points actual search starts from here lock_release(&mpLock); // Tell the threads that they have work to do. This will make them leave - // their idle loop. But before copy search stack tail for each thread. + // their idle loop. for (i = 0; i < activeThreads; i++) if (i == master || splitPoint.slaves[i]) { - memcpy(splitPoint.sstack[i], ss - 1, 4 * sizeof(SearchStack)); - assert(i == master || threads[i].state == THREAD_BOOKED); threads[i].state = THREAD_WORKISWAITING; // This makes the slave to exit from idle_loop() @@ -2542,9 +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(); @@ -2559,11 +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 @@ -2576,10 +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