X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmovepick.h;h=a7cac4ba85ba64c03ceb29f64a0aa2eca7d5a939;hb=27ba611a3da37423a3502e49beeebe11c9a11d8e;hp=b31d9dd2d48dafbdc3fc1f985e58189f645f5404;hpb=9ab84a816539ade23868f0383e39634e6ab88df5;p=stockfish

diff --git a/src/movepick.h b/src/movepick.h
index b31d9dd2..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) 2008-2009 Marco Costalba
+  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
@@ -17,97 +18,110 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-
-#if !defined MOVEPICK_H_INCLUDED
+#ifndef MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
 
-////
-//// Includes
-////
+#include <array>
 
-#include "depth.h"
-#include "history.h"
-#include "lock.h"
+#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 = int>
+struct StatBoards : public std::array<std::array<T, Size2>, Size1> {
 
-////
-//// Types
-////
+  void fill(const T& v) {
+    T* p = &(*this)[0][0];
+    std::fill(p, p + sizeof(*this) / sizeof(*p), v);
+  }
+};
 
-struct SearchStack;
+/// 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;
 
-enum MovegenPhase {
-  PH_NULL_MOVE,      // Null move
-  PH_TT_MOVES,       // Transposition table move and mate killer
-  PH_GOOD_CAPTURES,  // Queen promotions and captures with SEE values >= 0
-  PH_KILLERS,        // Killer moves from the current ply
-  PH_NONCAPTURES,    // Non-captures and underpromotions
-  PH_BAD_CAPTURES,   // Queen promotions and captures with SEE values < 0
-  PH_EVASIONS,       // Check evasions
-  PH_QCAPTURES,      // Captures in quiescence search
-  PH_QCHECKS,        // Non-capture checks in quiescence search
-  PH_STOP
-};
+/// PieceToBoards are addressed by a move's [piece][to] information
+typedef StatBoards<PIECE_NB, SQUARE_NB> PieceToBoards;
 
-typedef uint8_t MovegenPhaseT;
+/// 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 {
 
-/// MovePicker is a class which is used to pick one legal move at a time from
-/// the current position. It is initialized with a Position object and a few
-/// moves we have reason to believe are good. The most important method is
-/// MovePicker::pick_next_move(), which returns a new legal move each time it
-/// is called, until there are no legal 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 be strongest first.
+  void update(Color c, Move m, int v) {
 
-class MovePicker {
+    const int D = 324;
+    auto& entry = (*this)[c][from_to(m)];
 
-  MovePicker& operator=(const MovePicker&); // silence a warning under MSVC
+    assert(abs(v) <= D); // Consistency check for below formula
 
-public:
-  MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL, bool useNullMove = false);
-  Move get_next_move();
-  Move get_next_move(Lock& lock);
-  int number_of_moves() const;
-  Bitboard discovered_check_candidates() const;
+    entry += v * 32 - entry * abs(v) / D;
 
-private:
-  void score_captures();
-  void score_noncaptures();
-  void score_evasions();
-  void go_next_phase();
+    assert(abs(entry) <= 32 * D);
+  }
+};
 
-  const Position& pos;
-  const History& H;
-  MoveStack ttMoves[2], killers[2];
-  bool finished;
-  int numOfBadCaptures, phase;
-  const MovegenPhaseT* phasePtr;
-  MoveStack *curMove, *lastMove;
-  Bitboard dc, pinned;
-  MoveStack moves[256], badCaptures[64];
+/// 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);
+  }
 };
 
+/// CounterMoveStat stores counter moves indexed by [piece][to] of the previous
+/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic
+typedef StatBoards<PIECE_NB, SQUARE_NB, Move> CounterMoveStat;
+
+/// CounterMoveHistoryStat is like CounterMoveStat but instead of a move it
+/// stores a full history (based on PieceTo boards instead of ButterflyBoards).
+typedef StatBoards<PIECE_NB, SQUARE_NB, PieceToHistory> CounterMoveHistoryStat;
+
+
+/// 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; }
 
-////
-//// Inline functions
-////
+class MovePicker {
+public:
+  MovePicker(const MovePicker&) = delete;
+  MovePicker& operator=(const MovePicker&) = delete;
 
-/// MovePicker::number_of_moves() simply returns the numOfMoves member
-/// variable. It is intended to be used in positions where the side to move
-/// is in check, for detecting checkmates or situations where there is only
-/// a single reply to check.
+  MovePicker(const Position&, Move, Value);
+  MovePicker(const Position&, Move, Depth, Square);
+  MovePicker(const Position&, Move, Depth, Search::Stack*);
 
-inline int MovePicker::number_of_moves() const {
-  return int(lastMove - moves);
-}
+  Move next_move(bool skipQuiets = false);
 
-/// MovePicker::discovered_check_candidates() returns a bitboard containing
-/// all pieces which can possibly give discovered check. This bitboard is
-/// computed by the constructor function.
+private:
+  template<GenType> void score();
+  ExtMove* begin() { return cur; }
+  ExtMove* end() { return endMoves; }
 
-inline Bitboard MovePicker::discovered_check_candidates() const {
-  return dc;
-}
+  const Position& pos;
+  const Search::Stack* ss;
+  Move killers[2];
+  Move countermove;
+  Depth depth;
+  Move ttMove;
+  Square recaptureSquare;
+  Value threshold;
+  int stage;
+  ExtMove *cur, *endMoves, *endBadCaptures;
+  ExtMove moves[MAX_MOVES];
+};
 
-#endif // !defined(MOVEPICK_H_INCLUDED)
+#endif // #ifndef MOVEPICK_H_INCLUDED