WebSVN – Games.Chess Giants – Diff – /engine-stockfish/movepick.h

   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2016 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
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 */
 #ifndef MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
-#include <algorithm> // For std::max
+#include <array>
-#include <cstring>   // For std::memset
+#include <limits>
 #include "movegen.h"
 #include "position.h"
 #include "types.h"
+/// StatBoards is a generic 2-dimensional array used to store various statistics
+template<int Size1, int Size2, typename T = int16_t>
+struct StatBoards : public std::array<std::array<T, Size2>, Size1> {
-/// The Stats struct stores moves statistics. According to the template parameter
-/// the class can store History 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.
+  void fill(const T& v) {
-/// Countermoves store the move that refute a previous one. Entries are stored
+    T* p = &(*this)[0][0];
-/// using only the moving piece and destination square, hence two moves with
+    std::fill(p, p + sizeof(*this) / sizeof(*p), v);
-/// different origin but same destination and piece will be considered identical.
-template<typename T, bool CM = false>
-struct Stats {
+  }
-  static const Value Max = Value(1 << 28);
+  void update(T& entry, int bonus, const int D) {
-  const T* operator[](Piece pc) const { return table[pc]; }
-  T* operator[](Piece pc) { return table[pc]; }
+    assert(abs(bonus) <= D); // Ensure range is [-32 * D, 32 * D]
-  void clear() { std::memset(table, 0, sizeof(table)); }
+    assert(abs(32 * D) < (std::numeric_limits<T>::max)()); // Ensure we don't overflow
-  void update(Piece pc, Square to, Move m) { table[pc][to] = m; }
-  void update(Piece pc, Square to, Value v) {
-    if (abs(int(v)) >= 324)
+    entry += bonus * 32 - entry * abs(bonus) / D;
-        return;
-    table[pc][to] -= table[pc][to] * abs(int(v)) / (CM ? 936 : 324);
-    table[pc][to] += int(v) * 32;
+    assert(abs(entry) <= 32 * 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);
-private:
+  }
+  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;
-  T table[PIECE_NB][SQUARE_NB];
+    assert(abs(entry) <= W * D);
+  }
 };
-typedef Stats<Move> MoveStats;
-typedef Stats<Value, false> HistoryStats;
+/// ButterflyBoards are 2 tables (one for each color) indexed by the move's from
-typedef Stats<Value,  true> CounterMoveStats;
+/// and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards
-typedef Stats<CounterMoveStats> CounterMoveHistoryStats;
+typedef StatBoards<COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyBoards;
+/// PieceToBoards are addressed by a move's [piece][to] information
-struct FromToStats {
+typedef StatBoards<PIECE_NB, SQUARE_NB> PieceToBoards;
-  Value get(Color c, Move m) const { return table[c][from_sq(m)][to_sq(m)]; }
+/// CapturePieceToBoards are addressed by a move's [piece][to][captured piece type] information
-  void clear() { std::memset(table, 0, sizeof(table)); }
+typedef StatCubes<PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToBoards;
-  void update(Color c, Move m, Value v) {
+/// ButterflyHistory records how often quiet moves have been successful or
+/// unsuccessful during the current search, and is used for reduction and move
-    if (abs(int(v)) >= 324)
+/// ordering decisions. It uses ButterflyBoards as backing store.
-        return;
+struct ButterflyHistory : public ButterflyBoards {
-    Square from = from_sq(m);
+  void update(Color c, Move m, int bonus) {
-    Square to = to_sq(m);
+    StatBoards::update((*this)[c][from_to(m)], bonus, 324);
+  }
+};
-    table[c][from][to] -= table[c][from][to] * abs(int(v)) / 324;
+/// PieceToHistory is like ButterflyHistory, but is based on PieceToBoards
+struct PieceToHistory : public PieceToBoards {
+  void update(Piece pc, Square to, int bonus) {
-    table[c][from][to] += int(v) * 32;
+    StatBoards::update((*this)[pc][to], bonus, 936);
+  }
+};
+/// CapturePieceToHistory is like PieceToHistory, but is based on CapturePieceToBoards
+struct CapturePieceToHistory : public CapturePieceToBoards {
-private:
+  void update(Piece pc, Square to, PieceType captured, int bonus) {
-  Value table[COLOR_NB][SQUARE_NB][SQUARE_NB];
+    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;
+/// 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<PIECE_NB, SQUARE_NB, PieceToHistory> ContinuationHistory;
 /// 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, Value, const CapturePieceToHistory*);
-  MovePicker(const Position&, Move, Depth, Square);
+  MovePicker(const Position&, Move, Depth, const ButterflyHistory*,  const CapturePieceToHistory*, Square);
-  MovePicker(const Position&, Move, Depth, Search::Stack*);
+  MovePicker(const Position&, Move, Depth, const ButterflyHistory*, const CapturePieceToHistory*, const PieceToHistory**, Move, Move*);
-  Move next_move();
+  Move next_move(bool skipQuiets = false);
 private:
   template<GenType> void score();
   ExtMove* begin() { return cur; }
   ExtMove* end() { return endMoves; }
   const Position& pos;
+  const ButterflyHistory* mainHistory;
+  const CapturePieceToHistory* captureHistory;
-  const Search::Stack* ss;
+  const PieceToHistory** contHistory;
-  Move countermove;
+  Move ttMove, countermove, killers[2];
-  Depth depth;
+  ExtMove *cur, *endMoves, *endBadCaptures;
-  Move ttMove;
+  int stage;
   Square recaptureSquare;
   Value threshold;
-  int stage;
+  Depth depth;
-  ExtMove *cur, *endMoves, *endBadCaptures;
   ExtMove moves[MAX_MOVES];
 };
 #endif // #ifndef MOVEPICK_H_INCLUDED

Subversion Repositories Games.Chess Giants

Games.Chess Giants/engine-stockfish/movepick.h – Rev 154 → 169