X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=4864b1cb151f70e2e1fc1849e198c9abc24802a6;hp=94bab30801d39dbb7c186333bf5d43410a166e07;hb=eabba1119f45f2ac8a3a6248bd1c1d9868d7af5c;hpb=bb6a6e159adf090413273e0ca92b4f2d0471ef68 diff --git a/src/search.cpp b/src/search.cpp index 94bab308..4864b1cb 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -49,7 +49,7 @@ namespace { const bool FakeSplit = false; // Different node types, used as template parameter - enum NodeType { Root, PV, NonPV, SplitPointPV, SplitPointNonPV }; + enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV }; // RootMove struct is used for moves at the root of the tree. For each root // move, we store a score, a node count, and a PV (really a refutation @@ -175,7 +175,6 @@ namespace { // Node counters, used only by thread[0] but try to keep in different cache // lines (64 bytes each) from the heavy multi-thread read accessed variables. - bool SendSearchedNodes; int NodesSincePoll; int NodesBetweenPolls = 30000; @@ -216,14 +215,14 @@ namespace { // MovePickerExt template class extends MovePicker and allows to choose at compile // time the proper moves source according to the type of node. In the default case // we simply create and use a standard MovePicker object. - template struct MovePickerExt : public MovePicker { + template struct MovePickerExt : public MovePicker { MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) : MovePicker(p, ttm, d, h, ss, b) {} }; // In case of a SpNode we use split point's shared MovePicker object as moves source - template<> struct MovePickerExt : public MovePicker { + template<> struct MovePickerExt : public MovePicker { MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) : MovePicker(p, ttm, d, h, ss, b), mp(ss->sp->mp) {} @@ -232,12 +231,6 @@ namespace { MovePicker* mp; }; - template<> struct MovePickerExt : public MovePickerExt { - - MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value b) - : MovePickerExt(p, ttm, d, h, ss, b) {} - }; - // 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) { @@ -373,7 +366,7 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { static Book book; // Initialize global search-related variables - StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = SendSearchedNodes = false; + StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = false; NodesSincePoll = 0; current_search_time(get_system_time()); Limits = limits; @@ -566,7 +559,8 @@ namespace { // 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() + // Search starting from ss+1 to allow referencing (ss-1). This is + // needed by update_gains() and ss copy when splitting at Root. value = search(pos, ss+1, alpha, beta, depth * ONE_PLY); // It is critical that sorting is done with a stable algorithm @@ -593,8 +587,7 @@ namespace { // 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, MultiPVIteration); i++) - { + for (int i = 0; i < Min(UCIMultiPV, MultiPVIteration + 1); i++) cout << "info" << depth_to_uci(depth * ONE_PLY) << (i == MultiPVIteration ? score_to_uci(Rml[i].score, alpha, beta) : @@ -602,7 +595,6 @@ namespace { << 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. @@ -701,9 +693,9 @@ namespace { template Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) { - const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV); - const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV); - const bool RootNode = (NT == Root); + const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV || NT == SplitPointRoot); + const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV || NT == SplitPointRoot); + const bool RootNode = (NT == Root || NT == SplitPointRoot); assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE); assert(beta > alpha && beta <= VALUE_INFINITE); @@ -719,7 +711,7 @@ namespace { Depth ext, newDepth; ValueType vt; Value bestValue, value, oldAlpha; - Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific + Value refinedValue, nullValue, futilityBase, futilityValue; bool isPvMove, inCheck, singularExtensionNode, givesCheck, captureOrPromotion, dangerous; int moveCount = 0, playedMoveCount = 0; Thread& thread = Threads[pos.thread()]; @@ -777,7 +769,7 @@ namespace { excludedMove = ss->excludedMove; posKey = excludedMove ? pos.get_exclusion_key() : pos.get_key(); tte = TT.probe(posKey); - ttMove = tte ? tte->move() : MOVE_NONE; + ttMove = RootNode ? Rml[MultiPVIteration].pv[0] : tte ? tte->move() : MOVE_NONE; // At PV nodes we check for exact scores, while at non-PV nodes we check for // a fail high/low. Biggest advantage at probing at PV nodes is to have a @@ -948,7 +940,7 @@ namespace { split_point_start: // At split points actual search starts from here // Initialize a MovePicker object for the current position - MovePickerExt mp(pos, RootNode ? Rml[MultiPVIteration].pv[0] : ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); + MovePickerExt mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); CheckInfo ci(pos); ss->bestMove = MOVE_NONE; futilityBase = ss->eval + ss->evalMargin; @@ -978,7 +970,7 @@ split_point_start: // At split points actual search starts from here // 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. + // in previous MultiPV Iteration. Finally any illegal move is skipped here. if (RootNode && !Rml.find(move, MultiPVIteration)) continue; @@ -1002,22 +994,15 @@ split_point_start: // At split points actual search starts from here // Save the current node count before the move is searched nodes = pos.nodes_searched(); - // If it's time to send nodes info, do it here where we have the - // correct accumulated node counts searched by each thread. - if (SendSearchedNodes) - { - SendSearchedNodes = false; - cout << "info" << speed_to_uci(pos.nodes_searched()) << endl; - } - // For long searches send current move info to GUI - if (current_search_time() > 2000) + if (pos.thread() == 0 && current_search_time() > 2000) cout << "info" << depth_to_uci(depth) - << " currmove " << move << " currmovenumber " << moveCount + MultiPVIteration << 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 && depth <= ONE_PLY) ? MAX_MOVES : 1)); + 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); @@ -1076,19 +1061,19 @@ split_point_start: // At split points actual search starts from here // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth, // but fixing this made program slightly weaker. Depth predictedDepth = newDepth - reduction(depth, moveCount); - futilityValueScaled = futilityBase + futility_margin(predictedDepth, moveCount) - + H.gain(pos.piece_on(move_from(move)), move_to(move)); + futilityValue = futilityBase + futility_margin(predictedDepth, moveCount) + + H.gain(pos.piece_on(move_from(move)), move_to(move)); - if (futilityValueScaled < beta) + if (futilityValue < beta) { if (SpNode) { lock_grab(&(sp->lock)); - if (futilityValueScaled > sp->bestValue) - sp->bestValue = bestValue = futilityValueScaled; + if (futilityValue > sp->bestValue) + sp->bestValue = bestValue = futilityValue; } - else if (futilityValueScaled > bestValue) - bestValue = futilityValueScaled; + else if (futilityValue > bestValue) + bestValue = futilityValue; continue; } @@ -1177,36 +1162,12 @@ split_point_start: // At split points actual search starts from here alpha = sp->alpha; } - if (value > bestValue) - { - bestValue = value; - ss->bestMove = move; - - if ( !RootNode - && PvNode - && value > alpha - && value < beta) // We want always alpha < beta - alpha = value; - - if (SpNode && !thread.cutoff_occurred()) - { - sp->bestValue = value; - sp->ss->bestMove = move; - sp->alpha = alpha; - sp->is_betaCutoff = (value >= beta); - } - } - - if (RootNode) + // 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 + // be trusted, and we don't update the best move and/or PV. + if (RootNode && !StopRequest) { - // 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 - // be trusted, and we break out of the loop without updating the best - // move and/or PV. - if (StopRequest) - break; - // Remember searched nodes counts for this move RootMove* rm = Rml.find(move); rm->nodes += pos.nodes_searched() - nodes; @@ -1223,10 +1184,6 @@ split_point_start: // At split points actual search starts from here // the best move changes frequently, we allocate some more time. if (!isPvMove && MultiPV == 1) Rml.bestMoveChanges++; - - // Update alpha. - if (value > alpha) - alpha = value; } else // All other moves but the PV are set to the lowest value, this @@ -1236,16 +1193,34 @@ split_point_start: // At split points actual search starts from here } // RootNode + if (value > bestValue) + { + bestValue = value; + ss->bestMove = move; + + if ( PvNode + && value > alpha + && value < beta) // We want always alpha < beta + alpha = value; + + if (SpNode && !thread.cutoff_occurred()) + { + sp->bestValue = value; + sp->ss->bestMove = move; + sp->alpha = alpha; + sp->is_betaCutoff = (value >= beta); + } + } + // Step 19. Check for split - if ( !RootNode - && !SpNode + if ( !SpNode && depth >= Threads.min_split_depth() && bestValue < beta && Threads.available_slave_exists(pos.thread()) && !StopRequest && !thread.cutoff_occurred()) - Threads.split(pos, ss, &alpha, beta, &bestValue, depth, - threatMove, moveCount, &mp, PvNode); + bestValue = Threads.split(pos, ss, alpha, beta, bestValue, depth, + threatMove, moveCount, &mp, NT); } // Step 20. Check for mate and stalemate @@ -1314,6 +1289,7 @@ split_point_start: // At split points actual search starts from here bool inCheck, enoughMaterial, givesCheck, evasionPrunable; const TTEntry* tte; Depth ttDepth; + ValueType vt; Value oldAlpha = alpha; ss->bestMove = ss->currentMove = MOVE_NONE; @@ -1384,7 +1360,7 @@ split_point_start: // At split points actual search starts from here CheckInfo ci(pos); // Loop through the moves until no moves remain or a beta cutoff occurs - while ( alpha < beta + while ( bestValue < beta && (move = mp.get_next_move()) != MOVE_NONE) { assert(move_is_ok(move)); @@ -1404,10 +1380,11 @@ split_point_start: // At split points actual search starts from here + piece_value_endgame(pos.piece_on(move_to(move))) + (move_is_ep(move) ? PawnValueEndgame : VALUE_ZERO); - if (futilityValue < alpha) + if (futilityValue < beta) { if (futilityValue > bestValue) bestValue = futilityValue; + continue; } @@ -1466,11 +1443,12 @@ split_point_start: // At split points actual search starts from here if (value > bestValue) { bestValue = value; - if (value > alpha) - { + ss->bestMove = move; + + if ( PvNode + && value > alpha + && value < beta) // We want always alpha < beta alpha = value; - ss->bestMove = move; - } } } @@ -1480,8 +1458,11 @@ split_point_start: // At split points actual search starts from here return value_mated_in(ss->ply); // Update transposition table - ValueType vt = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT); - TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, ss->bestMove, ss->eval, evalMargin); + move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove; + vt = bestValue <= oldAlpha ? VALUE_TYPE_UPPER + : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT; + + TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1961,9 +1942,6 @@ split_point_start: // At split points actual search starts from here dbg_print_mean(); dbg_print_hit_rate(); - - // Send info on searched nodes as soon as we return to root - SendSearchedNodes = true; } // Should we stop the search? @@ -2221,10 +2199,14 @@ void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) { memcpy(ss, tsp->ss - 1, 4 * sizeof(SearchStack)); (ss+1)->sp = tsp; - if (tsp->pvNode) + if (tsp->nodeType == Root) + search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); + else if (tsp->nodeType == PV) search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); - else + else if (tsp->nodeType == NonPV) search(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth); + else + assert(false); assert(threads[threadID].state == Thread::SEARCHING); @@ -2253,8 +2235,6 @@ void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) { // In helpful master concept a master can help only a sub-tree, and // because here is all finished is not possible master is booked. assert(threads[threadID].state == Thread::AVAILABLE); - - threads[threadID].state = Thread::SEARCHING; return; } }