X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=a7cac4ba85ba64c03ceb29f64a0aa2eca7d5a939;hp=c4676ca4f6e9f5be4b50be4462f92a3286ee9412;hb=1781439fc2bfb12f8a4e89b2a75fdeac6cd58672;hpb=e4695f15bc62c0e34572b3a995e25b7461d2ae90 diff --git a/src/movepick.h b/src/movepick.h index c4676ca4..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) 2008-2014 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 @@ -20,56 +21,70 @@ #ifndef MOVEPICK_H_INCLUDED #define MOVEPICK_H_INCLUDED -#include // For std::max -#include // For std::memset +#include #include "movegen.h" #include "position.h" -#include "search.h" #include "types.h" +/// StatBoards is a generic 2-dimensional array used to store various statistics +template +struct StatBoards : public std::array, Size1> { -/// The Stats struct stores moves statistics. According to the template parameter -/// the class can store History, Gains and Countermoves. History records how often -/// different moves have been successful or unsuccessful during the current search -/// and is used for reduction and move ordering decisions. Gains records the move's -/// best evaluation gain from one ply to the next and is used for pruning decisions. -/// Countermoves store the move that refute a previous one. Entries are stored -/// using only the moving piece and destination square, hence two moves with -/// different origin but same destination and piece will be considered identical. -template -struct Stats { + void fill(const T& v) { + T* p = &(*this)[0][0]; + std::fill(p, p + sizeof(*this) / sizeof(*p), v); + } +}; - static const Value Max = Value(2000); +/// 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; - const T* operator[](Piece p) const { return table[p]; } - void clear() { std::memset(table, 0, sizeof(table)); } +/// PieceToBoards are addressed by a move's [piece][to] information +typedef StatBoards PieceToBoards; - void update(Piece p, Square to, Move m) { +/// 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 { - if (m == table[p][to].first) - return; + void update(Color c, Move m, int v) { - table[p][to].second = table[p][to].first; - table[p][to].first = m; - } + const int D = 324; + auto& entry = (*this)[c][from_to(m)]; - void update(Piece p, Square to, Value v) { + assert(abs(v) <= D); // Consistency check for below formula - if (Gain) - table[p][to] = std::max(v, table[p][to] - 1); + entry += v * 32 - entry * abs(v) / D; - else if (abs(table[p][to] + v) < Max) - table[p][to] += v; + assert(abs(entry) <= 32 * D); } +}; -private: - T table[PIECE_NB][SQUARE_NB]; +/// 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); + } }; -typedef Stats< true, Value> GainsStats; -typedef Stats HistoryStats; -typedef Stats > MovesStats; +/// 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 @@ -78,33 +93,34 @@ typedef Stats > MovesStats; /// 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 { - - MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC - public: - MovePicker(const Position&, Move, Depth, const HistoryStats&, Square); - MovePicker(const Position&, Move, const HistoryStats&, PieceType); - MovePicker(const Position&, Move, Depth, const HistoryStats&, Move*, Move*, Search::Stack*); + 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*); - template Move next_move(); + Move next_move(bool skipQuiets = false); private: template void score(); - void generate_next_stage(); + ExtMove* begin() { return cur; } + ExtMove* end() { return endMoves; } const Position& pos; - const HistoryStats& history; - Search::Stack* ss; - Move* countermoves; - Move* followupmoves; + const Search::Stack* ss; + Move killers[2]; + Move countermove; Depth depth; Move ttMove; - ExtMove killers[6]; Square recaptureSquare; - int captureThreshold, stage; - ExtMove *cur, *end, *endQuiets, *endBadCaptures; + Value threshold; + int stage; + ExtMove *cur, *endMoves, *endBadCaptures; ExtMove moves[MAX_MOVES]; };