X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=41a83604e09e99b768360ebb66b382d7510918a8;hp=ae2ee3814ea838acf096ef3c73d3135892b16607;hb=ae6a4ebf1f44cb05e96f8f33342ec281b41b0cc0;hpb=b1b19343cd1f5ec65084dc11a0a0b4d5ece2a24b diff --git a/src/movepick.h b/src/movepick.h index ae2ee381..41a83604 100644 --- a/src/movepick.h +++ b/src/movepick.h @@ -21,68 +21,79 @@ #ifndef MOVEPICK_H_INCLUDED #define MOVEPICK_H_INCLUDED -#include // For std::memset +#include #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> { -/// HistoryStats records how often quiet moves have been successful or unsuccessful -/// during the current search, and is used for reduction and move ordering decisions. -struct HistoryStats { + void fill(const T& v) { + T* p = &(*this)[0][0]; + std::fill(p, p + sizeof(*this) / sizeof(*p), v); + } +}; + +/// 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; - static const int Max = 1 << 28; +/// PieceToBoards are addressed by a move's [piece][to] information +typedef StatBoards PieceToBoards; - int get(Color c, Move m) const { return table[c][from_sq(m)][to_sq(m)]; } - void clear() { std::memset(table, 0, sizeof(table)); } - void update(Color c, Move m, int v) { +/// 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 { - Square from = from_sq(m); - Square to = to_sq(m); + void update(Color c, Move m, int bonus) { const int D = 324; + auto& entry = (*this)[c][from_to(m)]; - assert(abs(int(v)) <= D); // Consistency check for below formula + assert(abs(bonus) <= D); // Consistency check for below formula + assert([&]{ + int v = entry + bonus * 32 - entry * abs(bonus) / D; + return INT16_MIN < v && v < INT16_MAX; + }()); - table[c][from][to] -= table[c][from][to] * abs(int(v)) / D; - table[c][from][to] += int(v) * 32; - } + entry += bonus * 32 - entry * abs(bonus) / D; -private: - int table[COLOR_NB][SQUARE_NB][SQUARE_NB]; + assert(abs(entry) <= 32 * D); + } }; +/// PieceToHistory is like ButterflyHistory, but is based on PieceToBoards +struct PieceToHistory : public PieceToBoards { -/// A template struct, used to generate MoveStats and CounterMoveHistoryStats: -/// MoveStats store the move that refute a previous one. -/// CounterMoveHistoryStats is like HistoryStats, but with two consecutive moves. -/// 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 { - const T* operator[](Piece pc) const { return table[pc]; } - T* operator[](Piece pc) { return table[pc]; } - void clear() { std::memset(table, 0, sizeof(table)); } - void update(Piece pc, Square to, Move m) { table[pc][to] = m; } - void update(Piece pc, Square to, int v) { + void update(Piece pc, Square to, int bonus) { const int D = 936; + auto& entry = (*this)[pc][to]; - assert(abs(int(v)) <= D); // Consistency check for below formula + assert(abs(bonus) <= D); // Consistency check for below formula + assert([&]{ + int v = entry + bonus * 32 - entry * abs(bonus) / D; + return INT16_MIN < v && v < INT16_MAX; + }()); - table[pc][to] -= table[pc][to] * abs(int(v)) / D; - table[pc][to] += int(v) * 32; - } + entry += bonus * 32 - entry * abs(bonus) / D; -private: - T table[PIECE_NB][SQUARE_NB]; + assert(abs(entry) <= 32 * D); + } }; -typedef Stats MoveStats; -typedef Stats CounterMoveStats; -typedef Stats CounterMoveHistoryStats; +/// 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 @@ -91,17 +102,14 @@ typedef Stats CounterMoveHistoryStats; /// 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*); - + 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: @@ -110,15 +118,14 @@ private: ExtMove* end() { return endMoves; } const Position& pos; - const Search::Stack* ss; - Move killers[2]; - Move countermove; - Depth depth; - Move ttMove; + const ButterflyHistory* mainHistory; + const PieceToHistory** contHistory; + Move ttMove, countermove, killers[2]; + ExtMove *cur, *endMoves, *endBadCaptures; + int stage; Square recaptureSquare; Value threshold; - int stage; - ExtMove *cur, *endMoves, *endBadCaptures; + Depth depth; ExtMove moves[MAX_MOVES]; };