X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=2fd842070cfe2720217eb6f8876aa02ba61075a7;hp=b6a494422a468315f4cb9cd31a9e2e004109345d;hb=1b6459195c82395d861cddf3f2056ed1c9a3bd5b;hpb=2acda1fde3e1542a0b1bfc5a0885559e6daf142a diff --git a/src/search.cpp b/src/search.cpp index b6a49442..2fd84207 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -2,7 +2,7 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -96,8 +96,6 @@ namespace { Move best = MOVE_NONE; }; - Value DrawValue[COLOR_NB]; - template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode, bool skipEarlyPruning); @@ -175,13 +173,7 @@ void Search::clear() { Time.availableNodes = 0; TT.clear(); - - for (Thread* th : Threads) - th->clear(); - - Threads.main()->callsCnt = 0; - Threads.main()->previousScore = VALUE_INFINITE; - Threads.main()->previousTimeReduction = 1; + Threads.clear(); } @@ -202,8 +194,9 @@ void MainThread::search() { TT.new_search(); int contempt = Options["Contempt"] * PawnValueEg / 100; // From centipawns - DrawValue[ us] = VALUE_DRAW - Value(contempt); - DrawValue[~us] = VALUE_DRAW + Value(contempt); + + Eval::Contempt = (us == WHITE ? make_score(contempt, contempt / 2) + : -make_score(contempt, contempt / 2)); if (rootMoves.empty()) { @@ -444,7 +437,7 @@ void Thread::search() { int improvingFactor = std::max(229, std::min(715, 357 + 119 * F[0] - 6 * F[1])); Color us = rootPos.side_to_move(); - bool thinkHard = DrawValue[us] == bestValue + bool thinkHard = bestValue == VALUE_DRAW && Limits.time[us] - Time.elapsed() > Limits.time[~us] && ::pv_is_draw(rootPos); @@ -532,8 +525,7 @@ namespace { { // Step 2. Check for aborted search and immediate draw if (Threads.stop.load(std::memory_order_relaxed) || pos.is_draw(ss->ply) || ss->ply >= MAX_PLY) - return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos) - : DrawValue[pos.side_to_move()]; + return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos) : VALUE_DRAW; // Step 3. Mate distance pruning. Even if we mate at the next move our score // would be at best mate_in(ss->ply+1), but if alpha is already bigger because @@ -559,7 +551,7 @@ namespace { // search to overwrite a previous full search TT value, so we use a different // position key in case of an excluded move. excludedMove = ss->excludedMove; - posKey = pos.key() ^ Key(excludedMove); + posKey = pos.key() ^ Key(excludedMove << 16); // isn't a very good hash tte = TT.probe(posKey, ttHit); ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; ttMove = rootNode ? thisThread->rootMoves[thisThread->PVIdx].pv[0] @@ -656,7 +648,7 @@ namespace { ss->staticEval, TT.generation()); } - if (skipEarlyPruning) + if (skipEarlyPruning || !pos.non_pawn_material(pos.side_to_move())) goto moves_loop; // Step 6. Razoring (skipped when in check) @@ -677,15 +669,14 @@ namespace { if ( !rootNode && depth < 7 * ONE_PLY && eval - futility_margin(depth) >= beta - && eval < VALUE_KNOWN_WIN // Do not return unproven wins - && pos.non_pawn_material(pos.side_to_move())) + && eval < VALUE_KNOWN_WIN) // Do not return unproven wins return eval; // Step 8. Null move search with verification search (is omitted in PV nodes) if ( !PvNode && eval >= beta && ss->staticEval >= beta - 36 * depth / ONE_PLY + 225 - && pos.non_pawn_material(pos.side_to_move())) + && (ss->ply >= thisThread->nmp_ply || ss->ply % 2 != thisThread->nmp_odd)) { assert(eval - beta >= 0); @@ -707,13 +698,19 @@ namespace { if (nullValue >= VALUE_MATE_IN_MAX_PLY) nullValue = beta; - if (depth < 12 * ONE_PLY && abs(beta) < VALUE_KNOWN_WIN) + if (abs(beta) < VALUE_KNOWN_WIN && (depth < 12 * ONE_PLY || thisThread->nmp_ply)) return nullValue; // Do verification search at high depths + // disable null move pruning for side to move for the first part of the remaining search tree + thisThread->nmp_ply = ss->ply + 3 * (depth-R) / 4; + thisThread->nmp_odd = ss->ply % 2; + Value v = depth-R < ONE_PLY ? qsearch(pos, ss, beta-1, beta) : search(pos, ss, beta-1, beta, depth-R, false, true); + thisThread->nmp_odd = thisThread->nmp_ply = 0; + if (v >= beta) return nullValue; } @@ -1076,7 +1073,7 @@ moves_loop: // When in check search starts from here if (!moveCount) bestValue = excludedMove ? alpha - : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; + : inCheck ? mated_in(ss->ply) : VALUE_DRAW; else if (bestMove) { // Quiet best move: update move sorting heuristics @@ -1144,8 +1141,7 @@ moves_loop: // When in check search starts from here // Check for an instant draw or if the maximum ply has been reached if (pos.is_draw(ss->ply) || ss->ply >= MAX_PLY) - return ss->ply >= MAX_PLY && !InCheck ? evaluate(pos) - : DrawValue[pos.side_to_move()]; + return ss->ply >= MAX_PLY && !InCheck ? evaluate(pos) : VALUE_DRAW; assert(0 <= ss->ply && ss->ply < MAX_PLY); @@ -1498,7 +1494,7 @@ moves_loop: // When in check search starts from here if (Threads.ponder) return; - if ( (Limits.use_time_management() && elapsed > Time.maximum()) + if ( (Limits.use_time_management() && elapsed > Time.maximum() - 10) || (Limits.movetime && elapsed >= Limits.movetime) || (Limits.nodes && Threads.nodes_searched() >= (uint64_t)Limits.nodes)) Threads.stop = true;