X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=f43def4d36fd51fd4f573c470a8866195890b531;hp=4cf45ad36202b715bd8c8e9efcdef4353256c186;hb=99e547f4cb190e462d0c582b731a0fcf25ce1545;hpb=5f58db8c9971d8709093ca3c97cecdc99c61303e diff --git a/src/movepick.cpp b/src/movepick.cpp index 4cf45ad3..f43def4d 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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2013 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 @@ -20,7 +20,6 @@ #include -#include "movegen.h" #include "movepick.h" #include "thread.h" @@ -36,14 +35,28 @@ namespace { STOP }; + // Our insertion sort, guaranteed to be stable, as is needed + void insertion_sort(ExtMove* begin, ExtMove* end) + { + ExtMove tmp, *p, *q; + + for (p = begin + 1; p < end; ++p) + { + tmp = *p; + for (q = p; q != begin && *(q-1) < tmp; --q) + *q = *(q-1); + *q = tmp; + } + } + // Unary predicate used by std::partition to split positive scores from remaining // ones so to sort separately the two sets, and with the second sort delayed. - inline bool has_positive_score(const MoveStack& ms) { return ms.score > 0; } + inline bool has_positive_score(const ExtMove& ms) { return ms.score > 0; } // Picks and moves to the front the best move in the range [begin, end), // it is faster than sorting all the moves in advance when moves are few, as // normally are the possible captures. - inline MoveStack* pick_best(MoveStack* begin, MoveStack* end) + inline ExtMove* pick_best(ExtMove* begin, ExtMove* end) { std::swap(*begin, *std::max_element(begin, end)); return begin; @@ -57,14 +70,15 @@ namespace { /// search captures, promotions and some checks) and about how important good /// move ordering is at the current node. -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, - Search::Stack* s, Value beta) : pos(p), Hist(h), depth(d) { +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h, Move* cm, + Search::Stack* s, Value beta) : pos(p), history(h), depth(d) { assert(d > DEPTH_ZERO); captureThreshold = 0; cur = end = moves; endBadCaptures = moves + MAX_MOVES - 1; + countermoves = cm; ss = s; if (p.checkers()) @@ -74,15 +88,12 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, { phase = MAIN_SEARCH; - killers[0].move = ss->killers[0]; - killers[1].move = ss->killers[1]; - // Consider sligtly negative captures as good if at low depth and far from beta - if (ss && ss->staticEval < beta - PawnValueMg && d < 3 * ONE_PLY) + if (ss->staticEval < beta - PawnValueMg && d < 3 * ONE_PLY) captureThreshold = -PawnValueMg; // Consider negative captures as good if still enough to reach beta - else if (ss && ss->staticEval > beta) + else if (ss->staticEval > beta) captureThreshold = beta - ss->staticEval; } @@ -90,8 +101,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, end += (ttMove != MOVE_NONE); } -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, - Square sq) : pos(p), Hist(h), cur(moves), end(moves) { +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h, + Square sq) : pos(p), history(h), cur(moves), end(moves) { assert(d <= DEPTH_ZERO); @@ -122,8 +133,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, end += (ttMove != MOVE_NONE); } -MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType pt) - : pos(p), Hist(h), cur(moves), end(moves) { +MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h, PieceType pt) + : pos(p), history(h), cur(moves), end(moves) { assert(!pos.checkers()); @@ -140,12 +151,10 @@ MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType } -/// MovePicker::score_captures(), MovePicker::score_noncaptures() and -/// MovePicker::score_evasions() assign a numerical move ordering score -/// to each move in a move list. The moves with highest scores will be -/// picked first by next_move(). - -void MovePicker::score_captures() { +/// score() assign a numerical move ordering score to each move in a move list. +/// The moves with highest scores will be picked first. +template<> +void MovePicker::score() { // Winning and equal captures in the main search are ordered by MVV/LVA. // Suprisingly, this appears to perform slightly better than SEE based // move ordering. The reason is probably that in a position with a winning @@ -161,7 +170,7 @@ void MovePicker::score_captures() { // some SEE calls in case we get a cutoff (idea from Pablo Vazquez). Move m; - for (MoveStack* it = moves; it != end; ++it) + for (ExtMove* it = moves; it != end; ++it) { m = it->move; it->score = PieceValue[MG][pos.piece_on(to_sq(m))] @@ -175,43 +184,43 @@ void MovePicker::score_captures() { } } -void MovePicker::score_noncaptures() { +template<> +void MovePicker::score() { Move m; - for (MoveStack* it = moves; it != end; ++it) + for (ExtMove* it = moves; it != end; ++it) { m = it->move; - it->score = Hist[pos.piece_moved(m)][to_sq(m)]; + it->score = history[pos.piece_moved(m)][to_sq(m)]; } } -void MovePicker::score_evasions() { +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. Move m; int seeScore; - if (end < moves + 2) - return; - - for (MoveStack* it = moves; it != end; ++it) + for (ExtMove* it = moves; it != end; ++it) { m = it->move; if ((seeScore = pos.see_sign(m)) < 0) - it->score = seeScore - History::Max; // Be sure we are at the bottom + it->score = seeScore - HistoryStats::Max; // At the bottom + else if (pos.is_capture(m)) it->score = PieceValue[MG][pos.piece_on(to_sq(m))] - - type_of(pos.piece_moved(m)) + History::Max; + - type_of(pos.piece_moved(m)) + HistoryStats::Max; else - it->score = Hist[pos.piece_moved(m)][to_sq(m)]; + it->score = history[pos.piece_moved(m)][to_sq(m)]; } } -/// MovePicker::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() generates, scores and sorts the next bunch of moves, when +/// there are no more moves to try for the current phase. void MovePicker::generate_next() { @@ -221,26 +230,39 @@ void MovePicker::generate_next() { case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6: end = generate(pos, moves); - score_captures(); + score(); return; case KILLERS_S1: cur = killers; end = cur + 2; + + killers[0].move = ss->killers[0]; + killers[1].move = ss->killers[1]; + killers[2].move = killers[3].move = MOVE_NONE; + + // Be sure countermoves are different from killers + for (int i = 0; i < 2; i++) + if (countermoves[i] != cur->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; + return; case QUIETS_1_S1: endQuiets = end = generate(pos, moves); - score_noncaptures(); + score(); end = std::partition(cur, end, has_positive_score); - sort(cur, end); + insertion_sort(cur, end); return; case QUIETS_2_S1: cur = end; end = endQuiets; if (depth >= 3 * ONE_PLY) - sort(cur, end); + insertion_sort(cur, end); return; case BAD_CAPTURES_S1: @@ -251,7 +273,8 @@ void MovePicker::generate_next() { case EVASIONS_S2: end = generate(pos, moves); - score_evasions(); + if (end > moves + 1) + score(); return; case QUIET_CHECKS_S3: @@ -270,11 +293,10 @@ void MovePicker::generate_next() { } -/// MovePicker::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 to return the tt move if has already been -/// searched previously. +/// next_move() is the most important method of the MovePicker class. It returns +/// a new pseudo legal move every time 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 has already been searched previously. template<> Move MovePicker::next_move() { @@ -318,7 +340,9 @@ Move MovePicker::next_move() { move = (cur++)->move; if ( move != ttMove && move != killers[0].move - && move != killers[1].move) + && move != killers[1].move + && move != killers[2].move + && move != killers[3].move) return move; break; @@ -361,6 +385,6 @@ Move MovePicker::next_move() { /// Version of next_move() to use at split point nodes where the move is grabbed /// from the split point's shared MovePicker object. This function is not thread -/// safe so should be lock protected by the caller. +/// safe so must be lock protected by the caller. template<> -Move MovePicker::next_move() { return ss->sp->mp->next_move(); } +Move MovePicker::next_move() { return ss->splitPoint->movePicker->next_move(); }