X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=b6e5620e5e333bd9a782ff70fe967a81dfc3c8c0;hp=ca052c7bd1901c250f35d0fea3aaf0c5fc422a05;hb=255df4ffae29f4a038c9881c1f2f675e2f21f71e;hpb=bb751d6c890f5c50c642366d601740366cfae8d0 diff --git a/src/movepick.h b/src/movepick.h index ca052c7b..b6e5620e 100644 --- a/src/movepick.h +++ b/src/movepick.h @@ -1,89 +1,150 @@ /* - Glaurung, a UCI chess playing engine. - Copyright (C) 2004-2008 Tord Romstad + 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) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad - Glaurung is free software: you can redistribute it and/or modify + Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. - - Glaurung is distributed in the hope that it will be useful, + + Stockfish is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - + You should have received a copy of the GNU General Public License along with this program. If not, see . */ - -#if !defined MOVEPICK_H_INCLUDED +#ifndef MOVEPICK_H_INCLUDED #define MOVEPICK_H_INCLUDED -//// -//// Includes -//// +#include +#include +#include -#include "depth.h" -#include "lock.h" +#include "movegen.h" #include "position.h" +#include "types.h" +/// StatsEntry stores the stat table value. It is usually a number but could +/// be a move or even a nested history. We use a class instead of naked value +/// to directly call history update operator<<() on the entry so to use stats +/// tables at caller sites as simple multi-dim arrays. +template +class StatsEntry { -//// -//// Types -//// + static const bool IsInt = std::is_integral::value; + typedef typename std::conditional::type TT; -/// MovePicker is a class which is used to pick one legal move at a time from -/// the current position. It is initialized with a Position object and a few -/// moves we have reason to believe are good. The most important method is -/// MovePicker::pick_next_move(), which returns a new legal move each time it -/// is called, until there are no legal moves left, when MOVE_NONE is returned. -/// In order to improve the efficiency of the alpha beta algorithm, MovePicker -/// attempts to return the moves which are most likely to be strongest first. - -class MovePicker { + T entry; public: - MovePicker(Position &p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, - Depth dpth); - Move get_next_move(); - Move get_next_move(Lock &lock); - int number_of_moves() const; - int current_move_score() const; - Bitboard discovered_check_candidates(); + T* get() { return &entry; } + void operator=(const T& v) { entry = v; } + operator TT() const { return entry; } - static void init_phase_table(); + void operator<<(int bonus) { + assert(abs(bonus) <= D); // Ensure range is [-D, D] + static_assert(D <= std::numeric_limits::max(), "D overflows T"); -private: - void score_captures(); - void score_noncaptures(); - void score_evasions(); - void score_qcaptures(); - Move pick_move_from_list(); - - Position *pos; - Move ttMove, mateKiller, killer1, killer2; - Bitboard pinned, dc; - MoveStack moves[256], badCaptures[64]; - bool pvNode; - Depth depth; - int phaseIndex; - int numOfMoves, numOfBadCaptures; - int movesPicked, badCapturesPicked; - bool finished; + entry += bonus - entry * abs(bonus) / D; + + assert(abs(entry) <= D); + } +}; + +/// Stats is a generic N-dimensional array used to store various statistics. +/// The first template parameter T is the base type of the array, the second +/// template parameter D limits the range of updates in [-D, D] when we update +/// values with the << operator, while the last parameters (Size and Sizes) +/// encode the dimensions of the array. +template +struct Stats : public std::array, Size> +{ + T* get() { return this->at(0).get(); } + + void fill(const T& v) { + T* p = get(); + std::fill(p, p + sizeof(*this) / sizeof(*p), v); + } }; +template +struct Stats : public std::array, Size> { + T* get() { return this->at(0).get(); } +}; + +/// In stats table, D=0 means that the template parameter is not used +enum StatsParams { NOT_USED = 0 }; + -//// -//// Inline functions -//// +/// ButterflyHistory records how often quiet moves have been successful or +/// unsuccessful during the current search, and is used for reduction and move +/// ordering decisions. It uses 2 tables (one for each color) indexed by +/// the move's from and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards +typedef Stats ButterflyHistory; -/// MovePicker::discovered_check_candidates() returns a bitboard containing -/// all pieces which can possibly give discovered check. This bitboard is -/// computed by the constructor function. +/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous +/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic +typedef Stats CounterMoveHistory; -inline Bitboard MovePicker::discovered_check_candidates() { - return dc; -} +/// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type] +typedef Stats CapturePieceToHistory; + +/// PieceToHistory is like ButterflyHistory but is addressed by a move's [piece][to] +typedef Stats PieceToHistory; + +/// ContinuationHistory is the combined history of a given pair of moves, usually +/// the current one given a previous one. The nested history table is based on +/// PieceToHistory instead of ButterflyBoards. +typedef Stats ContinuationHistory; + + +/// MovePicker class is used to pick one pseudo legal move at a time from the +/// current position. The most important method is next_move(), which returns a +/// new pseudo legal move each time it is called, until there are no moves left, +/// when MOVE_NONE is returned. In order to improve the efficiency of the alpha +/// beta algorithm, MovePicker attempts to return the moves which are most likely +/// to get a cut-off first. +class MovePicker { + + enum PickType { Next, Best }; + +public: + MovePicker(const MovePicker&) = delete; + MovePicker& operator=(const MovePicker&) = delete; + MovePicker(const Position&, Move, Value, const CapturePieceToHistory*); + MovePicker(const Position&, Move, Depth, const ButterflyHistory*, + const CapturePieceToHistory*, + Square); + MovePicker(const Position&, Move, Depth, const ButterflyHistory*, + const CapturePieceToHistory*, + const PieceToHistory**, + Move, + Move*); + Move next_move(bool skipQuiets = false); + +private: + template Move select(Pred); + template void score(); + ExtMove* begin() { return cur; } + ExtMove* end() { return endMoves; } + + const Position& pos; + const ButterflyHistory* mainHistory; + const CapturePieceToHistory* captureHistory; + const PieceToHistory** contHistory; + Move ttMove; + ExtMove refutations[3], *cur, *endMoves, *endBadCaptures; + int stage; + Move move; + Square recaptureSquare; + Value threshold; + Depth depth; + ExtMove moves[MAX_MOVES]; +}; -#endif // !defined(MOVEPICK_H_INCLUDED) +#endif // #ifndef MOVEPICK_H_INCLUDED