X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=7eab970a866ea27f30f3a500240affc98fac1b8b;hp=7d982c7f45bc1232eb850af7d1b3527195ae22a0;hb=b2edac7075ca238326378cb2c5ef09f7cdb2fd9e;hpb=6661a3154152ab448b1dc11d882586976f616f92 diff --git a/src/search.cpp b/src/search.cpp index 7d982c7f..7eab970a 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -41,7 +41,6 @@ namespace Search { LimitsType Limits; RootMoveVector RootMoves; Position RootPos; - TimePoint SearchTime; StateStackPtr SetupStates; } @@ -67,14 +66,14 @@ namespace { enum NodeType { Root, PV, NonPV }; // Razoring and futility margin based on depth - inline Value razor_margin(Depth d) { return Value(512 + 32 * d); } - inline Value futility_margin(Depth d) { return Value(200 * d); } + Value razor_margin(Depth d) { return Value(512 + 32 * d); } + Value futility_margin(Depth d) { return Value(200 * d); } // Futility and reductions lookup tables, initialized at startup int FutilityMoveCounts[2][16]; // [improving][depth] Depth Reductions[2][2][64][64]; // [pv][improving][depth][moveNumber] - template inline Depth reduction(bool i, Depth d, int mn) { + template Depth reduction(bool i, Depth d, int mn) { return Reductions[PvNode][i][std::min(d, 63 * ONE_PLY)][std::min(mn, 63)]; } @@ -130,13 +129,11 @@ namespace { }; size_t PVIdx; - TimeManager TimeMgr; EasyMoveManager EasyMove; double BestMoveChanges; Value DrawValue[COLOR_NB]; HistoryStats History; CounterMovesHistoryStats CounterMovesHistory; - GainsStats Gains; MovesStats Countermoves; template @@ -183,6 +180,17 @@ void Search::init() { } +/// Search::reset() clears all search memory, to obtain reproducible search results + +void Search::reset () { + + TT.clear(); + History.clear(); + CounterMovesHistory.clear(); + Countermoves.clear(); +} + + /// Search::perft() is our utility to verify move generation. All the leaf nodes /// up to the given depth are generated and counted and the sum returned. template @@ -219,11 +227,12 @@ template uint64_t Search::perft(Position& pos, Depth depth); void Search::think() { - TimeMgr.init(Limits, RootPos.side_to_move(), RootPos.game_ply()); + Color us = RootPos.side_to_move(); + Time.init(Limits, us, RootPos.game_ply(), now()); int contempt = Options["Contempt"] * PawnValueEg / 100; // From centipawns - DrawValue[ RootPos.side_to_move()] = VALUE_DRAW - Value(contempt); - DrawValue[~RootPos.side_to_move()] = VALUE_DRAW + Value(contempt); + DrawValue[ us] = VALUE_DRAW - Value(contempt); + DrawValue[~us] = VALUE_DRAW + Value(contempt); TB::Hits = 0; TB::RootInTB = false; @@ -292,6 +301,11 @@ void Search::think() { Threads.timer->run = false; } + // When playing in 'nodes as time' mode, subtract the searched nodes from + // the available ones before to exit. + if (Limits.npmsec) + Time.availableNodes += Limits.inc[us] - RootPos.nodes_searched(); + // When we reach the maximum depth, we can arrive here without a raise of // Signals.stop. However, if we are pondering or in an infinite search, // the UCI protocol states that we shouldn't print the best move before the @@ -335,10 +349,6 @@ namespace { beta = VALUE_INFINITE; TT.new_search(); - History.clear(); - CounterMovesHistory.clear(); - Gains.clear(); - Countermoves.clear(); size_t multiPV = Options["MultiPV"]; Skill skill(Options["Skill Level"]); @@ -402,7 +412,7 @@ namespace { // the UI) before a re-search. if ( multiPV == 1 && (bestValue <= alpha || bestValue >= beta) - && now() - SearchTime > 3000) + && Time.elapsed() > 3000) sync_cout << UCI::pv(pos, depth, alpha, beta) << sync_endl; // In case of failing low/high increase aspiration window and @@ -433,9 +443,9 @@ namespace { if (Signals.stop) sync_cout << "info nodes " << RootPos.nodes_searched() - << " time " << now() - SearchTime << sync_endl; + << " time " << Time.elapsed() << sync_endl; - else if (PVIdx + 1 == multiPV || now() - SearchTime > 3000) + else if (PVIdx + 1 == multiPV || Time.elapsed() > 3000) sync_cout << UCI::pv(pos, depth, alpha, beta) << sync_endl; } @@ -456,16 +466,16 @@ namespace { { // Take some extra time if the best move has changed if (depth > 4 * ONE_PLY && multiPV == 1) - TimeMgr.pv_instability(BestMoveChanges); + Time.pv_instability(BestMoveChanges); // Stop the search if only one legal move is available or all // of the available time has been used or we matched an easyMove // from the previous search and just did a fast verification. if ( RootMoves.size() == 1 - || now() - SearchTime > TimeMgr.available_time() + || Time.elapsed() > Time.available() || ( RootMoves[0].pv[0] == easyMove && BestMoveChanges < 0.03 - && now() - SearchTime > TimeMgr.available_time() / 10)) + && Time.elapsed() > Time.available() / 10)) { // If we are allowed to ponder do not stop the search now but // keep pondering until the GUI sends "ponderhit" or "stop". @@ -485,7 +495,7 @@ namespace { // Clear any candidate easy move that wasn't stable for the last search // iterations; the second condition prevents consecutive fast moves. - if (EasyMove.stableCnt < 6 || now() - SearchTime < TimeMgr.available_time()) + if (EasyMove.stableCnt < 6 || Time.elapsed() < Time.available()) EasyMove.clear(); // If skill level is enabled, swap best PV line with the sub-optimal one @@ -595,7 +605,7 @@ namespace { ss->currentMove = ttMove; // Can be MOVE_NONE // If ttMove is quiet, update killers, history, counter move on TT hit - if (ttValue >= beta && ttMove && !pos.capture_or_promotion(ttMove) && !inCheck) + if (ttValue >= beta && ttMove && !pos.capture_or_promotion(ttMove)) update_stats(pos, ss, ttMove, depth, nullptr, 0); return ttValue; @@ -631,7 +641,7 @@ namespace { } } - // Step 5. Evaluate the position statically and update parent's gain statistics + // Step 5. Evaluate the position statically if (inCheck) { ss->staticEval = eval = VALUE_NONE; @@ -660,23 +670,11 @@ namespace { if (ss->skipEarlyPruning) goto moves_loop; - if ( !pos.captured_piece_type() - && ss->staticEval != VALUE_NONE - && (ss-1)->staticEval != VALUE_NONE - && (move = (ss-1)->currentMove) != MOVE_NULL - && move != MOVE_NONE - && type_of(move) == NORMAL) - { - Square to = to_sq(move); - Gains.update(pos.piece_on(to), to, -(ss-1)->staticEval - ss->staticEval); - } - // Step 6. Razoring (skipped when in check) if ( !PvNode && depth < 4 * ONE_PLY && eval + razor_margin(depth) <= alpha - && ttMove == MOVE_NONE - && !pos.pawn_on_7th(pos.side_to_move())) + && ttMove == MOVE_NONE) { if ( depth <= ONE_PLY && eval + razor_margin(3 * ONE_PLY) <= alpha) @@ -833,7 +831,7 @@ moves_loop: // When in check and at SpNode search starts from here { Signals.firstRootMove = (moveCount == 1); - if (thisThread == Threads.main() && now() - SearchTime > 3000) + if (thisThread == Threads.main() && Time.elapsed() > 3000) sync_cout << "info depth " << depth / ONE_PLY << " currmove " << UCI::move(move, pos.is_chess960()) << " currmovenumber " << moveCount + PVIdx << sync_endl; @@ -846,7 +844,7 @@ moves_loop: // When in check and at SpNode search starts from here captureOrPromotion = pos.capture_or_promotion(move); givesCheck = type_of(move) == NORMAL && !ci.dcCandidates - ? ci.checkSq[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) + ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) : pos.gives_check(move, ci); dangerous = givesCheck @@ -903,8 +901,7 @@ moves_loop: // When in check and at SpNode search starts from here // Futility pruning: parent node if (predictedDepth < 7 * ONE_PLY) { - futilityValue = ss->staticEval + futility_margin(predictedDepth) - + 128 + Gains[pos.moved_piece(move)][to_sq(move)]; + futilityValue = ss->staticEval + futility_margin(predictedDepth) + 256; if (futilityValue <= alpha) { @@ -941,8 +938,6 @@ moves_loop: // When in check and at SpNode search starts from here } ss->currentMove = move; - if (!SpNode && !captureOrPromotion && quietCount < 64) - quietsSearched[quietCount++] = move; // Step 14. Make the move pos.do_move(move, st, givesCheck); @@ -958,13 +953,15 @@ moves_loop: // When in check and at SpNode search starts from here ss->reduction = reduction(improving, depth, moveCount); if ( (!PvNode && cutNode) - || History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO - || ( History[pos.piece_on(to_sq(move))][to_sq(move)] - + CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq] - [pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO)) + || ( History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO + && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq] + [pos.piece_on(to_sq(move))][to_sq(move)] <= VALUE_ZERO)) ss->reduction += ONE_PLY; - if (move == countermove) + if ( move == countermove + || ( History[pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO + && CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq] + [pos.piece_on(to_sq(move))][to_sq(move)] > VALUE_ZERO)) ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY); // Decrease reduction for moves that escape a capture @@ -980,13 +977,6 @@ moves_loop: // When in check and at SpNode search starts from here value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); - // Re-search at intermediate depth if reduction is very high - if (value > alpha && ss->reduction >= 4 * ONE_PLY) - { - Depth d2 = std::max(newDepth - 2 * ONE_PLY, ONE_PLY); - value = -search(pos, ss+1, -(alpha+1), -alpha, d2, true); - } - doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO); ss->reduction = DEPTH_ZERO; } @@ -1097,6 +1087,9 @@ moves_loop: // When in check and at SpNode search starts from here } } + if (!SpNode && !captureOrPromotion && move != bestMove && quietCount < 64) + quietsSearched[quietCount++] = move; + // Step 19. Check for splitting the search if ( !SpNode && Threads.size() >= 2 @@ -1140,8 +1133,8 @@ moves_loop: // When in check and at SpNode search starts from here : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; // Quiet best move: update killers, history and countermoves - else if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck) - update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1); + else if (bestMove && !pos.capture_or_promotion(bestMove)) + update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount); tte->save(posKey, value_to_tt(bestValue, ss->ply), bestValue >= beta ? BOUND_LOWER : @@ -1269,7 +1262,7 @@ moves_loop: // When in check and at SpNode search starts from here assert(is_ok(move)); givesCheck = type_of(move) == NORMAL && !ci.dcCandidates - ? ci.checkSq[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) + ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move) : pos.gives_check(move, ci); // Futility pruning @@ -1298,8 +1291,7 @@ moves_loop: // When in check and at SpNode search starts from here // Detect non-capture evasions that are candidates to be pruned evasionPrunable = InCheck && bestValue > VALUE_MATED_IN_MAX_PLY - && !pos.capture(move) - && !pos.can_castle(pos.side_to_move()); + && !pos.capture(move); // Don't search moves with negative SEE values if ( (!InCheck || evasionPrunable) @@ -1399,10 +1391,12 @@ moves_loop: // When in check and at SpNode search starts from here *pv = MOVE_NONE; } - // update_stats() updates killers, history and countermoves stats after a fail-high - // of a quiet move. - void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) { + // update_stats() updates killers, history, countermove history and + // countermoves stats for a quiet best move. + + void update_stats(const Position& pos, Stack* ss, Move move, + Depth depth, Move* quiets, int quietsCnt) { if (ss->killers[0] != move) { @@ -1433,7 +1427,7 @@ moves_loop: // When in check and at SpNode search starts from here } // Extra penalty for TT move in previous ply when it gets refuted - if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove) + if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove && !pos.captured_piece_type()) { Square prevPrevSq = to_sq((ss-2)->currentMove); HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq]; @@ -1482,7 +1476,7 @@ moves_loop: // When in check and at SpNode search starts from here string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { std::stringstream ss; - TimePoint elapsed = now() - SearchTime + 1; + int elapsed = Time.elapsed() + 1; size_t multiPV = std::min((size_t)Options["MultiPV"], RootMoves.size()); int selDepth = 0; @@ -1726,7 +1720,7 @@ void Thread::idle_loop() { void check_time() { static TimePoint lastInfoTime = now(); - TimePoint elapsed = now() - SearchTime; + int elapsed = Time.elapsed(); if (now() - lastInfoTime >= 1000) { @@ -1742,10 +1736,10 @@ void check_time() { { bool stillAtFirstMove = Signals.firstRootMove && !Signals.failedLowAtRoot - && elapsed > TimeMgr.available_time() * 75 / 100; + && elapsed > Time.available() * 75 / 100; if ( stillAtFirstMove - || elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution) + || elapsed > Time.maximum() - 2 * TimerThread::Resolution) Signals.stop = true; } else if (Limits.movetime && elapsed >= Limits.movetime)