X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=9411b5a701d34ef4070b64d14213016b45766426;hp=2a090b1b30c38640f0fe2d656d85ecf851fea14e;hb=94dd204c3b10ebe0e6c8df5d7c98de5ba4906cad;hpb=431c3ac485386cc10413fc8a3c7d338dcc71602d diff --git a/src/movepick.cpp b/src/movepick.cpp index 2a090b1b..9411b5a7 100644 --- a/src/movepick.cpp +++ b/src/movepick.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) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2014 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 @@ -49,9 +49,9 @@ namespace { } } - // Unary predicate used by std::partition to split positive scores from remaining + // Unary predicate used by std::partition to split positive values from remaining // ones so as to sort the two sets separately, with the second sort delayed. - inline bool has_positive_score(const ExtMove& ms) { return ms.score > 0; } + inline bool has_positive_value(const ExtMove& move) { return move.value > 0; } // Picks the best move in the range (begin, end) and moves it to the front. // It's faster than sorting all the moves in advance when there are few @@ -61,7 +61,7 @@ namespace { std::swap(*begin, *std::max_element(begin, end)); return begin; } -} +} // namespace /// Constructors of the MovePicker class. As arguments we pass information @@ -71,16 +71,17 @@ namespace { /// ordering is at the current node. MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h, - Move* cm, Search::Stack* s) : pos(p), history(h), depth(d) { + Move* cm, Move* fm, Search::Stack* s) : pos(p), history(h), depth(d) { assert(d > DEPTH_ZERO); cur = end = moves; endBadCaptures = moves + MAX_MOVES - 1; countermoves = cm; + followupmoves = fm; ss = s; - if (p.checkers()) + if (pos.checkers()) stage = EVASION; else @@ -91,30 +92,23 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& } MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h, - Square sq) : pos(p), history(h), cur(moves), end(moves) { + Square s) : pos(p), history(h), cur(moves), end(moves) { assert(d <= DEPTH_ZERO); - if (p.checkers()) + if (pos.checkers()) stage = EVASION; else if (d > DEPTH_QS_NO_CHECKS) stage = QSEARCH_0; else if (d > DEPTH_QS_RECAPTURES) - { stage = QSEARCH_1; - // Skip TT move if is not a capture or a promotion. This avoids qsearch - // tree explosion due to a possible perpetual check or similar rare cases - // when TT table is full. - if (ttm && !pos.capture_or_promotion(ttm)) - ttm = MOVE_NONE; - } else { stage = RECAPTURE; - recaptureSquare = sq; + recaptureSquare = s; ttm = MOVE_NONE; } @@ -141,8 +135,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h, Piece } -/// score() assign a numerical move ordering score to each move in a move list. -/// The moves with highest scores will be picked first. +/// score() assign a numerical value to each move in a move list. The moves with +/// highest values will be picked first. template<> void MovePicker::score() { // Winning and equal captures in the main search are ordered by MVV/LVA. @@ -163,14 +157,14 @@ void MovePicker::score() { for (ExtMove* it = moves; it != end; ++it) { m = it->move; - it->score = PieceValue[MG][pos.piece_on(to_sq(m))] - - type_of(pos.moved_piece(m)); + it->value = PieceValue[MG][pos.piece_on(to_sq(m))] + - Value(type_of(pos.moved_piece(m))); - if (type_of(m) == PROMOTION) - it->score += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN]; + if (type_of(m) == ENPASSANT) + it->value += PieceValue[MG][PAWN]; - else if (type_of(m) == ENPASSANT) - it->score += PieceValue[MG][PAWN]; + else if (type_of(m) == PROMOTION) + it->value += PieceValue[MG][promotion_type(m)] - PieceValue[MG][PAWN]; } } @@ -182,7 +176,7 @@ void MovePicker::score() { for (ExtMove* it = moves; it != end; ++it) { m = it->move; - it->score = history[pos.moved_piece(m)][to_sq(m)]; + it->value = history[pos.moved_piece(m)][to_sq(m)]; } } @@ -190,29 +184,29 @@ template<> void MovePicker::score() { // Try good captures ordered by MVV/LVA, then non-captures if destination square // is not under attack, ordered by history value, then bad-captures and quiet - // moves with a negative SEE. This last group is ordered by the SEE score. + // moves with a negative SEE. This last group is ordered by the SEE value. Move m; - int seeScore; + Value see; for (ExtMove* it = moves; it != end; ++it) { m = it->move; - if ((seeScore = pos.see_sign(m)) < 0) - it->score = seeScore - HistoryStats::Max; // At the bottom + if ((see = pos.see_sign(m)) < VALUE_ZERO) + it->value = see - HistoryStats::Max; // At the bottom else if (pos.capture(m)) - it->score = PieceValue[MG][pos.piece_on(to_sq(m))] - - type_of(pos.moved_piece(m)) + HistoryStats::Max; + it->value = PieceValue[MG][pos.piece_on(to_sq(m))] + - Value(type_of(pos.moved_piece(m))) + HistoryStats::Max; else - it->score = history[pos.moved_piece(m)][to_sq(m)]; + it->value = history[pos.moved_piece(m)][to_sq(m)]; } } -/// generate_next() generates, scores and sorts the next bunch of moves, when -/// there are no more moves to try for the current phase. +/// generate_next_stage() generates, scores and sorts the next bunch of moves, +/// when there are no more moves to try for the current stage. -void MovePicker::generate_next() { +void MovePicker::generate_next_stage() { cur = moves; @@ -230,21 +224,30 @@ void MovePicker::generate_next() { killers[0].move = ss->killers[0]; killers[1].move = ss->killers[1]; killers[2].move = killers[3].move = MOVE_NONE; + killers[4].move = killers[5].move = MOVE_NONE; + + // Please note that following code is racy and could yield to rare (less + // than 1 out of a million) duplicated entries in SMP case. This is harmless. // Be sure countermoves are different from killers for (int i = 0; i < 2; ++i) - if (countermoves[i] != cur->move && countermoves[i] != (cur+1)->move) + if ( countermoves[i] != (cur+0)->move + && countermoves[i] != (cur+1)->move) (end++)->move = countermoves[i]; - if (countermoves[1] && countermoves[1] == countermoves[0]) // Due to SMP races - killers[3].move = MOVE_NONE; - + // Be sure followupmoves are different from killers and countermoves + for (int i = 0; i < 2; ++i) + if ( followupmoves[i] != (cur+0)->move + && followupmoves[i] != (cur+1)->move + && followupmoves[i] != (cur+2)->move + && followupmoves[i] != (cur+3)->move) + (end++)->move = followupmoves[i]; return; case QUIETS_1_S1: endQuiets = end = generate(pos, moves); score(); - end = std::partition(cur, end, has_positive_score); + end = std::partition(cur, end, has_positive_value); insertion_sort(cur, end); return; @@ -273,6 +276,8 @@ void MovePicker::generate_next() { case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE: stage = STOP; + /* Fall through */ + case STOP: end = cur + 1; // Avoid another next_phase() call return; @@ -285,8 +290,8 @@ void MovePicker::generate_next() { /// next_move() is the most important method of the MovePicker class. It returns /// a new pseudo legal move every time it is called, until there are no more moves -/// left. It picks the move with the biggest score from a list of generated moves -/// taking care not returning the ttMove if it has already been searched previously. +/// left. It picks the move with the biggest value from a list of generated moves +/// taking care not to return the ttMove if it has already been searched. template<> Move MovePicker::next_move() { @@ -295,7 +300,7 @@ Move MovePicker::next_move() { while (true) { while (cur == end) - generate_next(); + generate_next_stage(); switch (stage) { @@ -307,7 +312,7 @@ Move MovePicker::next_move() { move = pick_best(cur++, end)->move; if (move != ttMove) { - if (pos.see_sign(move) >= 0) + if (pos.see_sign(move) >= VALUE_ZERO) return move; // Losing capture, move it to the tail of the array @@ -318,8 +323,8 @@ Move MovePicker::next_move() { case KILLERS_S1: move = (cur++)->move; if ( move != MOVE_NONE - && pos.pseudo_legal(move) && move != ttMove + && pos.pseudo_legal(move) && !pos.capture(move)) return move; break; @@ -330,7 +335,9 @@ Move MovePicker::next_move() { && move != killers[0].move && move != killers[1].move && move != killers[2].move - && move != killers[3].move) + && move != killers[3].move + && move != killers[4].move + && move != killers[5].move) return move; break;