X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=baae494b9e6073f656a2ca715d7d91bf63cf843b;hp=9393db6505f106db0eb7b57ecc034444cefa34df;hb=9d7a36121a2a192f530933f7fdd77f37db19142e;hpb=939b621e5c67e9ef89b409fd773d38058341906c diff --git a/src/search.cpp b/src/search.cpp index 9393db65..baae494b 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, 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 @@ -20,9 +20,9 @@ #include #include #include -#include #include #include +#include #include #include @@ -47,6 +47,8 @@ namespace Search { } using std::string; +using std::cout; +using std::endl; using namespace Search; namespace { @@ -65,7 +67,6 @@ namespace { RootMove(){} RootMove(Move m) { - nodes = 0; score = prevScore = -VALUE_INFINITE; pv.push_back(m); pv.push_back(MOVE_NONE); @@ -77,7 +78,6 @@ namespace { void extract_pv_from_tt(Position& pos); void insert_pv_in_tt(Position& pos); - int64_t nodes; Value score; Value prevScore; std::vector pv; @@ -188,7 +188,7 @@ namespace { MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, Stack* ss, Value b) : MovePicker(p, ttm, d, h, ss, b), mp(ss->sp->mp) {} - Move get_next_move() { return mp->get_next_move(); } + Move next_move() { return mp->next_move(); } MovePicker* mp; }; @@ -294,12 +294,12 @@ void Search::think() { || count(SearchMoves.begin(), SearchMoves.end(), ml.move())) RootMoves.push_back(RootMove(ml.move())); - if (Options["OwnBook"].value()) + if (Options["OwnBook"]) { - if (Options["Book File"].value() != book.name()) - book.open(Options["Book File"].value()); + if (book.name() != (string)Options["Book File"]) + book.open(Options["Book File"]); - Move bookMove = book.probe(pos, Options["Best Book Move"].value()); + Move bookMove = book.probe(pos, Options["Best Book Move"]); if ( bookMove != MOVE_NONE && count(RootMoves.begin(), RootMoves.end(), bookMove)) @@ -313,31 +313,31 @@ void Search::think() { read_evaluation_uci_options(pos.side_to_move()); Threads.read_uci_options(); - TT.set_size(Options["Hash"].value()); - if (Options["Clear Hash"].value()) + TT.set_size(Options["Hash"]); + if (Options["Clear Hash"]) { - Options["Clear Hash"].set_value("false"); + Options["Clear Hash"] = false; TT.clear(); } - UCIMultiPV = Options["MultiPV"].value(); - SkillLevel = Options["Skill Level"].value(); + UCIMultiPV = Options["MultiPV"]; + SkillLevel = Options["Skill Level"]; // Do we have to play with skill handicap? In this case enable MultiPV that // we will use behind the scenes to retrieve a set of possible moves. SkillLevelEnabled = (SkillLevel < 20); MultiPV = (SkillLevelEnabled ? std::max(UCIMultiPV, (size_t)4) : UCIMultiPV); - if (Options["Use Search Log"].value()) + if (Options["Use Search Log"]) { - Log log(Options["Search Log Filename"].value()); + Log log(Options["Search Log Filename"]); log << "\nSearching: " << pos.to_fen() << "\ninfinite: " << Limits.infinite << " ponder: " << Limits.ponder << " time: " << Limits.time << " increment: " << Limits.increment << " moves to go: " << Limits.movesToGo - << std::endl; + << endl; } for (int i = 0; i < Threads.size(); i++) @@ -360,18 +360,18 @@ void Search::think() { Threads.set_timer(0); Threads.set_size(1); - if (Options["Use Search Log"].value()) + if (Options["Use Search Log"]) { int e = elapsed_time(); - Log log(Options["Search Log Filename"].value()); + Log log(Options["Search Log Filename"]); log << "Nodes: " << pos.nodes_searched() << "\nNodes/second: " << (e > 0 ? pos.nodes_searched() * 1000 / e : 0) << "\nBest move: " << move_to_san(pos, RootMoves[0].pv[0]); StateInfo st; pos.do_move(RootMoves[0].pv[0], st); - log << "\nPonder move: " << move_to_san(pos, RootMoves[0].pv[1]) << std::endl; + log << "\nPonder move: " << move_to_san(pos, RootMoves[0].pv[1]) << endl; pos.undo_move(RootMoves[0].pv[0]); } @@ -384,9 +384,8 @@ finish: Threads.wait_for_stop_or_ponderhit(); // Best move could be MOVE_NONE when searching on a stalemate position - printf("bestmove %s ponder %s\n", - move_to_uci(RootMoves[0].pv[0], Chess960).c_str(), - move_to_uci(RootMoves[0].pv[1], Chess960).c_str()); + cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], Chess960) + << " ponder " << move_to_uci(RootMoves[0].pv[1], Chess960) << endl; } @@ -409,11 +408,11 @@ namespace { bestValue = delta = -VALUE_INFINITE; ss->currentMove = MOVE_NULL; // Hack to skip update gains - // Handle the special case of a mate/stalemate position + // Handle the special case of a mated/stalemate position if (RootMoves.empty()) { - printf("info depth 0%s\n", - score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW).c_str()); + cout << "info depth 0 score " + << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << endl; RootMoves.push_back(MOVE_NONE); return; @@ -475,7 +474,7 @@ namespace { // If search has been stopped exit the aspiration window loop. // Sorting and writing PV back to TT is safe becuase RootMoves - // is still valid, although refers to previous iteration. + // is still valid, although refers to previous iteration. if (Signals.stop) break; @@ -511,7 +510,7 @@ namespace { if (SkillLevelEnabled && depth == 1 + SkillLevel) skillBest = do_skill_level(); - if (Options["Use Search Log"].value()) + if (Options["Use Search Log"]) pv_info_to_log(pos, depth, bestValue, elapsed_time(), &RootMoves[0].pv[0]); // Filter out startup noise when monitoring best move stability @@ -587,13 +586,12 @@ namespace { 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); - assert(PvNode || alpha == beta - 1); + assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); + assert(PvNode == (alpha != beta - 1)); + assert(depth > DEPTH_ZERO); assert(pos.thread() >= 0 && pos.thread() < Threads.size()); Move movesSearched[MAX_MOVES]; - int64_t nodes; StateInfo st; const TTEntry *tte; Key posKey; @@ -639,11 +637,16 @@ namespace { || ss->ply > PLY_MAX) && !RootNode) return VALUE_DRAW; - // Step 3. Mate distance pruning + // 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 + // a shorter mate was found upward in the tree then there is no need to search + // further, we will never beat current alpha. Same logic but with reversed signs + // applies also in the opposite condition of being mated instead of giving mate, + // in this case return a fail-high score. if (!RootNode) { - alpha = std::max(value_mated_in(ss->ply), alpha); - beta = std::min(value_mate_in(ss->ply+1), beta); + alpha = std::max(mated_in(ss->ply), alpha); + beta = std::min(mate_in(ss->ply+1), beta); if (alpha >= beta) return alpha; } @@ -652,7 +655,7 @@ namespace { // We don't want the score of a partial 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 = excludedMove ? pos.get_exclusion_key() : pos.get_key(); + posKey = excludedMove ? pos.exclusion_key() : pos.key(); tte = TT.probe(posKey); ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE; @@ -700,7 +703,7 @@ namespace { if ( (move = (ss-1)->currentMove) != MOVE_NULL && (ss-1)->eval != VALUE_NONE && ss->eval != VALUE_NONE - && pos.captured_piece_type() == PIECE_TYPE_NONE + && pos.captured_piece_type() == NO_PIECE_TYPE && !is_special(move)) { Square to = move_to(move); @@ -815,7 +818,7 @@ namespace { MovePicker mp(pos, ttMove, H, pos.captured_piece_type()); CheckInfo ci(pos); - while ((move = mp.get_next_move()) != MOVE_NONE) + while ((move = mp.next_move()) != MOVE_NONE) if (pos.pl_move_is_legal(move, ci.pinned)) { pos.do_move(move, st, ci, pos.move_gives_check(move, ci)); @@ -866,7 +869,7 @@ split_point_start: // At split points actual search starts from here // Step 11. Loop through moves // Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs while ( bestValue < beta - && (move = mp.get_next_move()) != MOVE_NONE + && (move = mp.next_move()) != MOVE_NONE && !thread.cutoff_occurred()) { assert(is_ok(move)); @@ -895,11 +898,11 @@ split_point_start: // At split points actual search starts from here if (RootNode) { Signals.firstRootMove = (moveCount == 1); - nodes = pos.nodes_searched(); if (pos.thread() == 0 && elapsed_time() > 2000) - printf("info depth %i currmove %s currmovenumber %i\n", depth / ONE_PLY, - move_to_uci(move, Chess960).c_str(), moveCount + PVIdx); + cout << "info depth " << depth / ONE_PLY + << " currmove " << move_to_uci(move, Chess960) + << " currmovenumber " << moveCount + PVIdx << endl; } isPvMove = (PvNode && moveCount <= 1); @@ -1061,7 +1064,6 @@ split_point_start: // At split points actual search starts from here if (RootNode && !Signals.stop) { RootMove& rm = *find(RootMoves.begin(), RootMoves.end(), move); - rm.nodes += pos.nodes_searched() - nodes; // PV move or new best move ? if (isPvMove || value > alpha) @@ -1120,7 +1122,7 @@ split_point_start: // At split points actual search starts from here // harmless because return value is discarded anyhow in the parent nodes. // If we are in a singular extension search then return a fail low score. if (!moveCount) - return excludedMove ? oldAlpha : inCheck ? value_mated_in(ss->ply) : VALUE_DRAW; + return excludedMove ? oldAlpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW; // If we have pruned all the moves without searching return a fail-low score if (bestValue == -VALUE_INFINITE) @@ -1141,7 +1143,9 @@ split_point_start: // At split points actual search starts from here TT.store(posKey, value_to_tt(bestValue, ss->ply), vt, depth, move, ss->eval, ss->evalMargin); // Update killers and history for non capture cut-off moves - if (bestValue >= beta && !pos.is_capture_or_promotion(move)) + if ( bestValue >= beta + && !pos.is_capture_or_promotion(move) + && !inCheck) { if (move != ss->killers[0]) { @@ -1186,10 +1190,9 @@ split_point_start: // At split points actual search starts from here const bool PvNode = (NT == PV); assert(NT == PV || NT == NonPV); - assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE); - assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE); - assert(PvNode || alpha == beta - 1); - assert(depth <= 0); + assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); + assert(PvNode == (alpha != beta - 1)); + assert(depth <= DEPTH_ZERO); assert(pos.thread() >= 0 && pos.thread() < Threads.size()); StateInfo st; @@ -1216,7 +1219,7 @@ split_point_start: // At split points actual search starts from here // Transposition table lookup. At PV nodes, we don't use the TT for // pruning, but only for move ordering. - tte = TT.probe(pos.get_key()); + tte = TT.probe(pos.key()); ttMove = (tte ? tte->move() : MOVE_NONE); if (!PvNode && tte && can_return_tt(tte, ttDepth, beta, ss->ply)) @@ -1248,7 +1251,7 @@ split_point_start: // At split points actual search starts from here if (bestValue >= beta) { if (!tte) - TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin); + TT.store(pos.key(), value_to_tt(bestValue, ss->ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin); return bestValue; } @@ -1269,7 +1272,7 @@ split_point_start: // At split points actual search starts from here // Loop through the moves until no moves remain or a beta cutoff occurs while ( bestValue < beta - && (move = mp.get_next_move()) != MOVE_NONE) + && (move = mp.next_move()) != MOVE_NONE) { assert(is_ok(move)); @@ -1362,14 +1365,14 @@ split_point_start: // At split points actual search starts from here // All legal moves have been searched. A special case: If we're in check // and no legal moves were found, it is checkmate. if (inCheck && bestValue == -VALUE_INFINITE) - return value_mated_in(ss->ply); + return mated_in(ss->ply); // Plies to mate from the root // Update transposition table 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); + TT.store(pos.key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1487,7 +1490,7 @@ split_point_start: // At split points actual search starts from here // value_to_tt() adjusts a mate score from "plies to mate from the root" to - // "plies to mate from the current ply". Non-mate scores are unchanged. + // "plies to mate from the current position". Non-mate scores are unchanged. // The function is called before storing a value to the transposition table. Value value_to_tt(Value v, int ply) { @@ -1502,8 +1505,9 @@ split_point_start: // At split points actual search starts from here } - // value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score from - // the transposition table to a mate score corrected for the current ply. + // value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score + // from the transposition table (where refers to the plies to mate/be mated + // from current position) to "plies to mate/be mated from the root". Value value_from_tt(Value v, int ply) { @@ -1598,9 +1602,9 @@ split_point_start: // At split points actual search starts from here static int searchStartTime; if (reset) - searchStartTime = get_system_time(); + searchStartTime = system_time(); - return get_system_time() - searchStartTime; + return system_time() - searchStartTime; } @@ -1615,10 +1619,10 @@ split_point_start: // At split points actual search starts from here std::stringstream s; - if (abs(v) < VALUE_MATE - PLY_MAX * ONE_PLY) - s << " score cp " << int(v) * 100 / int(PawnValueMidgame); // Scale to centipawns + if (abs(v) < VALUE_MATE_IN_PLY_MAX) + s << "cp " << v * 100 / int(PawnValueMidgame); else - s << " score mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2; + s << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2; s << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : ""); @@ -1634,7 +1638,6 @@ split_point_start: // At split points actual search starts from here int t = elapsed_time(); int selDepth = 0; - std::stringstream s; for (int i = 0; i < Threads.size(); i++) if (Threads[i].maxPly > selDepth) @@ -1649,19 +1652,19 @@ split_point_start: // At split points actual search starts from here int d = (updated ? depth : depth - 1); Value v = (updated ? RootMoves[i].score : RootMoves[i].prevScore); - - s << "info depth " << d - << " seldepth " << selDepth - << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v)) - << " nodes " << pos.nodes_searched() - << " nps " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0) - << " time " << t - << " multipv " << i + 1 << " pv"; + std::stringstream s; for (int j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++) s << " " << move_to_uci(RootMoves[i].pv[j], Chess960); - printf("%s\n", s.str().c_str()); // Much faster than std::cout + cout << "info depth " << d + << " seldepth " << selDepth + << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v)) + << " nodes " << pos.nodes_searched() + << " nps " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0) + << " time " << t + << " multipv " << i + 1 + << " pv" << s.str() << endl; } } @@ -1750,8 +1753,8 @@ split_point_start: // At split points actual search starts from here while (m != pv) pos.undo_move(*--m); - Log l(Options["Search Log Filename"].value()); - l << s.str() << std::endl; + Log l(Options["Search Log Filename"]); + l << s.str() << endl; } @@ -1765,7 +1768,7 @@ split_point_start: // At split points actual search starts from here static RKISS rk; // PRNG sequence should be not deterministic - for (int i = abs(get_system_time() % 50); i > 0; i--) + for (int i = abs(system_time() % 50); i > 0; i--) rk.rand(); // RootMoves are already sorted by score in descending order @@ -1818,7 +1821,7 @@ split_point_start: // At split points actual search starts from here pv.push_back(m); pos.do_move(m, *st++); - while ( (tte = TT.probe(pos.get_key())) != NULL + while ( (tte = TT.probe(pos.key())) != NULL && tte->move() != MOVE_NONE && pos.is_pseudo_legal(tte->move()) && pos.pl_move_is_legal(tte->move(), pos.pinned_pieces()) @@ -1850,7 +1853,7 @@ split_point_start: // At split points actual search starts from here assert(pv[ply] != MOVE_NONE && pos.is_pseudo_legal(pv[ply])); do { - k = pos.get_key(); + k = pos.key(); tte = TT.probe(k); // Don't overwrite existing correct entries @@ -1968,9 +1971,9 @@ void do_timer_event() { static int lastInfoTime; int e = elapsed_time(); - if (get_system_time() - lastInfoTime >= 1000 || !lastInfoTime) + if (system_time() - lastInfoTime >= 1000 || !lastInfoTime) { - lastInfoTime = get_system_time(); + lastInfoTime = system_time(); dbg_print_mean(); dbg_print_hit_rate();