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
+ Copyright (C) 2015-2018 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
#define MOVEPICK_H_INCLUDED
#include <array>
+#include <limits>
#include "movegen.h"
#include "position.h"
void update(T& entry, int bonus, const int D) {
- assert([&]{
- int v = entry + bonus * 32 - entry * abs(bonus) / D;
- return INT16_MIN < v && v < INT16_MAX;
- }());
-
- assert(abs(bonus) <= D); // Consistency check for below formula
+ assert(abs(bonus) <= D); // Ensure range is [-32 * D, 32 * D]
+ assert(abs(32 * D) < (std::numeric_limits<T>::max)()); // Ensure we don't overflow
entry += bonus * 32 - entry * abs(bonus) / D;
}
};
+/// StatCubes is a generic 3-dimensional array used to store various statistics
+template<int Size1, int Size2, int Size3, typename T = int16_t>
+struct StatCubes : public std::array<std::array<std::array<T, Size3>, Size2>, Size1> {
+
+ void fill(const T& v) {
+ T* p = &(*this)[0][0][0];
+ std::fill(p, p + sizeof(*this) / sizeof(*p), v);
+ }
+
+ void update(T& entry, int bonus, const int D, const int W) {
+
+ assert(abs(bonus) <= D); // Ensure range is [-W * D, W * D]
+ assert(abs(W * D) < (std::numeric_limits<T>::max)()); // Ensure we don't overflow
+
+ entry += bonus * W - entry * abs(bonus) / D;
+
+ assert(abs(entry) <= W * D);
+ }
+};
+
/// 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<COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyBoards;
/// PieceToBoards are addressed by a move's [piece][to] information
typedef StatBoards<PIECE_NB, SQUARE_NB> PieceToBoards;
+/// CapturePieceToBoards are addressed by a move's [piece][to][captured piece type] information
+typedef StatCubes<PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToBoards;
+
/// 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.
}
};
+/// CapturePieceToHistory is like PieceToHistory, but is based on CapturePieceToBoards
+struct CapturePieceToHistory : public CapturePieceToBoards {
+
+ void update(Piece pc, Square to, PieceType captured, int bonus) {
+ StatCubes::update((*this)[pc][to][captured], bonus, 324, 2);
+ }
+};
+
/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic
typedef StatBoards<PIECE_NB, SQUARE_NB, Move> CounterMoveHistory;
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*);
+ MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
+ MovePicker(const Position&, Move, Depth, const ButterflyHistory*, const CapturePieceToHistory*, Square);
+ MovePicker(const Position&, Move, Depth, const ButterflyHistory*, const CapturePieceToHistory*, const PieceToHistory**, Move, Move*);
Move next_move(bool skipQuiets = false);
private:
const Position& pos;
const ButterflyHistory* mainHistory;
+ const CapturePieceToHistory* captureHistory;
const PieceToHistory** contHistory;
Move ttMove, countermove, killers[2];
ExtMove *cur, *endMoves, *endBadCaptures;