X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=21a130332e4bfdf5e1626e070232bab67c0954e9;hp=8414e32901b769bd9ec1a93989478923063ab12d;hb=2550c6383b4646d64ab431cbb573991353ed7a2e;hpb=ecec7dbf894ae76fb44750ffe429496fb05fcceb diff --git a/src/search.cpp b/src/search.cpp index 8414e329..21a13033 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -23,6 +23,7 @@ //// #include +#include #include #include #include @@ -60,11 +61,10 @@ namespace { struct IterationInfoType { - IterationInfoType(Value v = Value(0), Value sv = Value(0), bool fh = false, bool fl = false) - : value(v), speculatedValue(sv), failHigh(fh), failLow(fl) {} + IterationInfoType(Value v = Value(0), Value sv = Value(0)) + : value(v), speculatedValue(sv) {} Value value, speculatedValue; - bool failHigh, failLow; }; @@ -129,18 +129,17 @@ namespace { }; - /// Constants and variables + /// Constants and variables initialized from UCI options // Minimum number of full depth (i.e. non-reduced) moves at PV and non-PV - // nodes: - int LMRPVMoves = 15; - int LMRNonPVMoves = 4; + // nodes + int LMRPVMoves, LMRNonPVMoves; - // Depth limit for use of dynamic threat detection: - Depth ThreatDepth = 5*OnePly; + // Depth limit for use of dynamic threat detection + Depth ThreatDepth; - // Depth limit for selective search: - Depth SelectiveDepth = 7*OnePly; + // Depth limit for selective search + Depth SelectiveDepth; // Use internal iterative deepening? const bool UseIIDAtPVNodes = true; @@ -177,33 +176,28 @@ namespace { const bool PruneBlockingMoves = false; // Use futility pruning? - bool UseQSearchFutilityPruning = true; - bool UseFutilityPruning = true; + bool UseQSearchFutilityPruning, UseFutilityPruning; // Margins for futility pruning in the quiescence search, and at frontier // and near frontier nodes - Value FutilityMarginQS = Value(0x80); + Value FutilityMarginQS; Value FutilityMargins[6] = { Value(0x100), Value(0x200), Value(0x250), Value(0x2A0), Value(0x340), Value(0x3A0) }; // Razoring const bool RazorAtDepthOne = false; - Depth RazorDepth = 4*OnePly; - Value RazorMargin = Value(0x300); + Depth RazorDepth; + Value RazorMargin; // Last seconds noise filtering (LSN) - bool UseLSNFiltering = false; + bool UseLSNFiltering; bool looseOnTime = false; - int LSNTime = 4 * 1000; // In milliseconds - Value LSNValue = Value(0x200); + int LSNTime; // In milliseconds + Value LSNValue; - // Extensions. Array index 0 is used at non-PV nodes, index 1 at PV nodes. - Depth CheckExtension[2] = {OnePly, OnePly}; - Depth SingleReplyExtension[2] = {OnePly / 2, OnePly / 2}; - Depth PawnPushTo7thExtension[2] = {OnePly / 2, OnePly / 2}; - Depth PassedPawnExtension[2] = {Depth(0), Depth(0)}; - Depth PawnEndgameExtension[2] = {OnePly, OnePly}; - Depth MateThreatExtension[2] = {Depth(0), Depth(0)}; + // Extensions. Array index 0 is used at non-PV nodes, index 1 at PV nodes. + Depth CheckExtension[2], SingleReplyExtension[2], PawnPushTo7thExtension[2]; + Depth PassedPawnExtension[2], PawnEndgameExtension[2], MateThreatExtension[2]; // Search depth at iteration 1 const Depth InitialDepth = OnePly /*+ OnePly/2*/; @@ -221,7 +215,7 @@ namespace { int BestMoveChangesByIteration[PLY_MAX_PLUS_2]; // MultiPV mode - int MultiPV = 1; + int MultiPV; // Time managment variables int SearchStartTime; @@ -241,15 +235,15 @@ namespace { int ExactMaxTime; // Show current line? - bool ShowCurrentLine = false; + bool ShowCurrentLine; // Log file - bool UseLogFile = false; + bool UseLogFile; std::ofstream LogFile; // MP related variables - Depth MinimumSplitDepth = 4*OnePly; - int MaxThreadsPerSplitPoint = 4; + Depth MinimumSplitDepth; + int MaxThreadsPerSplitPoint; Thread Threads[THREAD_MAX]; Lock MPLock; bool AllThreadsShouldExit = false; @@ -712,13 +706,14 @@ namespace { // Search to the current depth Value value = root_search(p, ss, rml, alpha, beta); - if (AbortSearch) - break; // Value cannot be trusted. Break out immediately! // Write PV to transposition table, in case the relevant entries have // been overwritten during the search. TT.insert_pv(p, ss[0].pv); + if (AbortSearch) + break; // Value cannot be trusted. Break out immediately! + //Save info about search result Value speculatedValue; bool fHigh = false; @@ -735,6 +730,7 @@ namespace { } else if (value <= alpha) { + assert(value == alpha); assert(delta < 0); fLow = true; @@ -744,7 +740,7 @@ namespace { speculatedValue = value; speculatedValue = Min(Max(speculatedValue, -VALUE_INFINITE), VALUE_INFINITE); - IterationInfo[Iteration] = IterationInfoType(value, speculatedValue, fHigh, fLow); + IterationInfo[Iteration] = IterationInfoType(value, speculatedValue); // Erase the easy move if it differs from the new best move if (ss[0].pv[0] != EasyMove) @@ -857,7 +853,6 @@ namespace { Value root_search(Position &pos, SearchStack ss[], RootMoveList &rml, Value alpha, Value beta) { - //FIXME: Implement bestValue Value oldAlpha = alpha; Value value; Bitboard dcCandidates = pos.discovered_check_candidates(pos.side_to_move()); @@ -867,8 +862,11 @@ namespace { { if (alpha >= beta) { + // We failed high, invalidate and skip next moves, leave node-counters + // and beta-counters as they are and quickly return, we will try to do + // a research at the next iteration with a bigger aspiration window. rml.set_move_score(i, -VALUE_INFINITE); - continue; // Leave node-counters and beta-counters as they are + continue; } int64_t nodes; Move move; @@ -951,7 +949,7 @@ namespace { rml.set_move_score(i, -VALUE_INFINITE); else { - // New best move! + // PV move or new best move! // Update PV rml.set_move_score(i, value); @@ -1377,7 +1375,7 @@ namespace { continue; // Value based pruning - if (depth < 7 * OnePly && approximateEval < beta) + if (approximateEval < beta) { if (futilityValue == VALUE_NONE) futilityValue = evaluate(pos, ei, threadID) @@ -1513,6 +1511,7 @@ namespace { return value_from_tt(tte->value(), ply); } } + Move ttMove = (tte ? tte->move() : MOVE_NONE); // Evaluate the position statically EvalInfo ei; @@ -1556,7 +1555,7 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth == 0) will be generated. - MovePicker mp = MovePicker(pos, pvNode, MOVE_NONE, EmptySearchStack, depth); + MovePicker mp = MovePicker(pos, pvNode, ttMove, EmptySearchStack, depth); Move move; int moveCount = 0; Bitboard dcCandidates = mp.discovered_check_candidates(); @@ -1633,22 +1632,20 @@ namespace { assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); // Update transposition table + Move m = ss[ply].pv[ply]; if (!pvNode) { Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1)); if (bestValue < beta) TT.store(pos, value_to_tt(bestValue, ply), d, MOVE_NONE, VALUE_TYPE_UPPER); else - TT.store(pos, value_to_tt(bestValue, ply), d, MOVE_NONE, VALUE_TYPE_LOWER); + TT.store(pos, value_to_tt(bestValue, ply), d, m, VALUE_TYPE_LOWER); } // Update killers only for good check moves - Move m = ss[ply].currentMove; if (alpha >= beta && ok_to_history(pos, m)) // Only non capture moves are considered - { - // Wrong to update history when depth is <= 0 update_killers(m, ss[ply]); - } + return bestValue; } @@ -2507,7 +2504,7 @@ namespace { return; bool overTime = t > AbsoluteMaxSearchTime - || (RootMoveNumber == 1 && t > MaxSearchTime + ExtraSearchTime && !FailLow) //FIXME: BUG?? + || (RootMoveNumber == 1 && t > MaxSearchTime + ExtraSearchTime && !FailLow) //FIXME: We are not checking any problem flags, BUG? || ( !FailHigh && !FailLow && !fail_high_ply_1() && !Problem && t > 6*(MaxSearchTime + ExtraSearchTime));