X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=03305ebdd8eab7cf02ce27fbdb56af2c22ada3e2;hp=09ad1c39bfe995ae791e3c1af58ad6b45e17b848;hb=9c35b9365d75a3522cee47536419534b1de91f48;hpb=94dcac1feeb142a56ed2ebddb96ef672460f1d49 diff --git a/src/movepick.h b/src/movepick.h index 09ad1c39..db0ba3c4 100644 --- a/src/movepick.h +++ b/src/movepick.h @@ -1,7 +1,8 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2009 Marco Costalba + Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, 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 @@ -17,74 +18,101 @@ along with this program. If not, see . */ - -#if !defined MOVEPICK_H_INCLUDED +#ifndef MOVEPICK_H_INCLUDED #define MOVEPICK_H_INCLUDED -//// -//// Includes -//// +#include -#include "depth.h" -#include "history.h" -#include "lock.h" +#include "movegen.h" #include "position.h" +#include "types.h" +/// StatBoards is a generic 2-dimensional array used to store various statistics +template +struct StatBoards : public std::array, Size1> { -//// -//// Types -//// + void fill(const T& v) { + T* p = &(*this)[0][0]; + std::fill(p, p + sizeof(*this) / sizeof(*p), v); + } -struct SearchStack; + void update(T& entry, int bonus, const int D) { -/// 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. + assert(abs(bonus) <= D); // Ensure range is [-32 * D, 32 * D] + assert(abs(32 * D) < INT16_MAX); // Ensure we don't overflow -class MovePicker { + entry += bonus * 32 - entry * abs(bonus) / D; - MovePicker& operator=(const MovePicker&); // silence a warning under MSVC + assert(abs(entry) <= 32 * D); + } +}; -public: - MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL); - Move get_next_move(); - Move get_next_move(Lock& lock); - int number_of_evasions() const; +/// ButterflyBoards are 2 tables (one for each color) indexed by the move's from +/// and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards +typedef StatBoards ButterflyBoards; -private: - void score_captures(); - void score_noncaptures(); - void score_evasions(); - void go_next_phase(); +/// PieceToBoards are addressed by a move's [piece][to] information +typedef StatBoards PieceToBoards; - const Position& pos; - const History& H; - MoveStack ttMoves[2], killers[2]; - bool finished; - int phase; - const uint8_t* phasePtr; - MoveStack *curMove, *lastMove, *lastBadCapture; - Bitboard pinned; - MoveStack moves[256], badCaptures[64]; +/// 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 ButterflyBoards as backing store. +struct ButterflyHistory : public ButterflyBoards { + + void update(Color c, Move m, int bonus) { + StatBoards::update((*this)[c][from_to(m)], bonus, 324); + } +}; + +/// PieceToHistory is like ButterflyHistory, but is based on PieceToBoards +struct PieceToHistory : public PieceToBoards { + + void update(Piece pc, Square to, int bonus) { + StatBoards::update((*this)[pc][to], bonus, 936); + } }; +/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous +/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic +typedef StatBoards CounterMoveHistory; + +/// ContinuationHistory is the history of a given pair of moves, usually the +/// current one given a previous one. History table is based on PieceToBoards +/// instead of ButterflyBoards. +typedef StatBoards ContinuationHistory; + -//// -//// Inline functions -//// +/// 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. -/// MovePicker::number_of_evasions() simply returns the number of moves in -/// evasions phase. It is intended to be used in positions where the side to -/// move is in check, for detecting checkmates or situations where there is -/// only a single reply to check. -/// WARNING: It works as long as PH_EVASIONS is the _only_ phase for evasions. +class MovePicker { +public: + MovePicker(const MovePicker&) = delete; + MovePicker& operator=(const MovePicker&) = delete; + MovePicker(const Position&, Move, Value); + MovePicker(const Position&, Move, Depth, const ButterflyHistory*, const PieceToHistory**, Square); + MovePicker(const Position&, Move, Depth, const ButterflyHistory*, const PieceToHistory**, Move, Move*); + Move next_move(bool skipQuiets = false); -inline int MovePicker::number_of_evasions() const { - return int(lastMove - moves); -} +private: + template void score(); + ExtMove* begin() { return cur; } + ExtMove* end() { return endMoves; } + + const Position& pos; + const ButterflyHistory* mainHistory; + const PieceToHistory** contHistory; + Move ttMove, countermove, killers[2]; + ExtMove *cur, *endMoves, *endBadCaptures; + int stage; + Square recaptureSquare; + Value threshold; + Depth depth; + ExtMove moves[MAX_MOVES]; +}; -#endif // !defined(MOVEPICK_H_INCLUDED) +#endif // #ifndef MOVEPICK_H_INCLUDED