X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=afd573ea459badabd1aa208b5d6dd498d49d455b;hp=9ffebc0038157c0be17f3094dc4a911e12578115;hb=b40e45c1cc51bd228898314264d6d241478b23d8;hpb=13c11f40480ec97316bd4da3a53787cc871037ea diff --git a/src/movepick.h b/src/movepick.h index 9ffebc00..afd573ea 100644 --- a/src/movepick.h +++ b/src/movepick.h @@ -2,6 +2,7 @@ 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) 2015-2017 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 @@ -20,58 +21,71 @@ #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(250); +/// 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 pc) const { return table[pc]; } - T* operator[](Piece pc) { return table[pc]; } - void clear() { std::memset(table, 0, sizeof(table)); } +/// PieceToBoards are addressed by a move's [piece][to] information +typedef StatBoards PieceToBoards; - void update(Piece pc, 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[pc][to].first) - return; + void update(Color c, Move m, int bonus) { - table[pc][to].second = table[pc][to].first; - table[pc][to].first = m; - } + const int D = 324; + auto& entry = (*this)[c][from_to(m)]; - void update(Piece pc, Square to, Value v) { + assert(abs(bonus) <= D); // Consistency check for below formula - if (Gain) - table[pc][to] = std::max(v, table[pc][to] - 1); + entry += bonus * 32 - entry * abs(bonus) / D; - else if (abs(table[pc][to] + v) < Max) - table[pc][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 bonus) { + + const int D = 936; + auto& entry = (*this)[pc][to]; + + assert(abs(bonus) <= D); // Consistency check for below formula + + entry += bonus * 32 - entry * abs(bonus) / D; + + assert(abs(entry) <= 32 * D); + } }; -typedef Stats< true, Value> GainsStats; -typedef Stats HistoryStats; -typedef Stats > MovesStats; -typedef Stats CounterMovesHistoryStats; +/// 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; /// MovePicker class is used to pick one pseudo legal move at a time from the @@ -85,33 +99,26 @@ class MovePicker { public: MovePicker(const MovePicker&) = delete; MovePicker& operator=(const MovePicker&) = delete; - - MovePicker(const Position&, Move, Depth, const HistoryStats&, const CounterMovesHistoryStats&, Square); - MovePicker(const Position&, Move, const HistoryStats&, const CounterMovesHistoryStats&, PieceType); - MovePicker(const Position&, Move, Depth, const HistoryStats&, const CounterMovesHistoryStats&, Move*, Move*, Search::Stack*); - - template Move next_move(); + 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); private: template void score(); - void generate_next_stage(); - ExtMove* begin() { return moves; } + ExtMove* begin() { return cur; } ExtMove* end() { return endMoves; } const Position& pos; - const HistoryStats& history; - const CounterMovesHistoryStats& counterMovesHistory; - Search::Stack* ss; - Move* countermoves; - Move* followupmoves; - Depth depth; - Move ttMove; - ExtMove killers[6]; - Square recaptureSquare; - Value captureThreshold; + const ButterflyHistory* mainHistory; + const PieceToHistory** contHistory; + Move ttMove, countermove, killers[2]; + ExtMove *cur, *endMoves, *endBadCaptures; int stage; - ExtMove *endQuiets, *endBadCaptures; - ExtMove moves[MAX_MOVES], *cur = moves, *endMoves = moves; + Square recaptureSquare; + Value threshold; + Depth depth; + ExtMove moves[MAX_MOVES]; }; #endif // #ifndef MOVEPICK_H_INCLUDED