X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmovepick.h;h=a7cac4ba85ba64c03ceb29f64a0aa2eca7d5a939;hb=53c2d9df5e76caa3d8f2421ff5430fd90bb8cc64;hp=ebb78787702a9d0b9c3538aedb978e8d99118126;hpb=9fc602bae74b8e09bd45ace3b42a8ce84d56b23c;p=stockfish diff --git a/src/movepick.h b/src/movepick.h index ebb78787..a7cac4ba 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) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + 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 @@ -17,71 +18,110 @@ 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 "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; +/// 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; -/// 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. +/// PieceToBoards are addressed by a move's [piece][to] information +typedef StatBoards PieceToBoards; -class MovePicker { +/// 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 { - MovePicker& operator=(const MovePicker&); // silence a warning under MSVC + void update(Color c, Move m, int v) { -public: - MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL, Value beta = -VALUE_INFINITE); - Move get_next_move(); - int number_of_evasions() const; + const int D = 324; + auto& entry = (*this)[c][from_to(m)]; -private: - void score_captures(); - void score_noncaptures(); - void score_evasions_or_checks(); - void go_next_phase(); + assert(abs(v) <= D); // Consistency check for below formula - const Position& pos; - const History& H; - MoveStack ttMoves[2], killers[2]; - int badCaptureThreshold, phase; - const uint8_t* phasePtr; - MoveStack *curMove, *lastMove, *lastGoodNonCapture, *lastBadCapture; - Bitboard pinned; - MoveStack moves[256], badCaptures[64]; + entry += v * 32 - entry * abs(v) / D; + + assert(abs(entry) <= 32 * D); + } +}; + +/// PieceToHistory is like ButterflyHistory, but is based on PieceToBoards +struct PieceToHistory : public PieceToBoards { + + void update(Piece pc, Square to, int v) { + + const int D = 936; + auto& entry = (*this)[pc][to]; + + assert(abs(v) <= D); // Consistency check for below formula + + entry += v * 32 - entry * abs(v) / D; + + assert(abs(entry) <= 32 * D); + } }; +/// CounterMoveStat stores counter moves indexed by [piece][to] of the previous +/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic +typedef StatBoards CounterMoveStat; + +/// CounterMoveHistoryStat is like CounterMoveStat but instead of a move it +/// stores a full history (based on PieceTo boards instead of ButterflyBoards). +typedef StatBoards CounterMoveHistoryStat; + + +/// 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. +namespace Search { struct Stack; } + +class MovePicker { +public: + MovePicker(const MovePicker&) = delete; + MovePicker& operator=(const MovePicker&) = delete; + + MovePicker(const Position&, Move, Value); + MovePicker(const Position&, Move, Depth, Square); + MovePicker(const Position&, Move, Depth, Search::Stack*); -//// -//// Inline functions -//// + Move next_move(bool skipQuiets = false); -/// 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. +private: + template void score(); + ExtMove* begin() { return cur; } + ExtMove* end() { return endMoves; } -inline int MovePicker::number_of_evasions() const { - return int(lastMove - moves); -} + const Position& pos; + const Search::Stack* ss; + Move killers[2]; + Move countermove; + Depth depth; + Move ttMove; + Square recaptureSquare; + Value threshold; + int stage; + ExtMove *cur, *endMoves, *endBadCaptures; + ExtMove moves[MAX_MOVES]; +}; -#endif // !defined(MOVEPICK_H_INCLUDED) +#endif // #ifndef MOVEPICK_H_INCLUDED