X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=d6451f6bf0ad4575212802a1708c4792a2ce5887;hp=5b40ded8e0b5911636e9651f0b81d380e186d198;hb=9001f55147fa304223623a6de0025ffe79f5fcc3;hpb=a7cdf7299a771949332f8c7ef77ae8fd125d0f08

diff --git a/src/movepick.h b/src/movepick.h
index 5b40ded8..d6451f6b 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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  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
@@ -17,49 +18,72 @@
   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
 
-#include <algorithm> // For std::max
-#include <cstring>   // For memset
+#include <array>
 
 #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<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 both History and Gains type statistics. 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. Entries are stored according only to moving piece and
-/// destination square, in particular two moves with different origin but same
-/// destination and same piece will be considered identical.
-template<bool Gain>
-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(2000);
+  void update(T& entry, int bonus, const int D) {
 
-  const Value* operator[](Piece p) const { return &table[p][0]; }
-  void clear() { memset(table, 0, sizeof(table)); }
+    assert([&]{
+      int v = entry + bonus * 32 - entry * abs(bonus) / D;
+      return INT16_MIN < v && v < INT16_MAX;
+    }());
 
-  void update(Piece p, Square to, Value v) {
+    assert(abs(bonus) <= D); // Consistency check for below formula
 
-    if (Gain)
-        table[p][to] = std::max(v, table[p][to] - 1);
+    entry += bonus * 32 - entry * abs(bonus) / D;
 
-    else if (abs(table[p][to] + v) < Max)
-        table[p][to] +=  v;
+    assert(abs(entry) <= 32 * D);
   }
+};
 
-private:
-  Value table[PIECE_NB][SQUARE_NB];
+/// 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;
+
+/// 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 {
+
+  void update(Color c, Move m, int bonus) {
+    StatBoards::update((*this)[c][from_to(m)], bonus, 324);
+  }
+};
+
+/// PieceToHistory is like ButterflyHistory, but is based on PieceToBoards
+struct PieceToHistory : public PieceToBoards {
+
+  void update(Piece pc, Square to, int bonus) {
+    StatBoards::update((*this)[pc][to], bonus, 936);
+  }
 };
 
-typedef Stats<false> History;
-typedef Stats<true> Gains;
+/// 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
@@ -70,29 +94,29 @@ typedef Stats<true> Gains;
 /// to get a cut-off first.
 
 class MovePicker {
-
-  MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
-
 public:
-  MovePicker(const Position&, Move, Depth, const History&, Search::Stack*, Value);
-  MovePicker(const Position&, Move, Depth, const History&, Square);
-  MovePicker(const Position&, Move, const History&, PieceType);
-  template<bool SpNode> Move next_move();
+  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*);
+  Move next_move(bool skipQuiets = false);
 
 private:
   template<GenType> void score();
-  void generate_next();
+  ExtMove* begin() { return cur; }
+  ExtMove* end() { return endMoves; }
 
   const Position& pos;
-  const History& Hist;
-  Search::Stack* ss;
-  Depth depth;
-  Move ttMove;
-  MoveStack killers[2];
+  const ButterflyHistory* mainHistory;
+  const PieceToHistory** contHistory;
+  Move ttMove, countermove, killers[2];
+  ExtMove *cur, *endMoves, *endBadCaptures;
+  int stage;
   Square recaptureSquare;
-  int captureThreshold, phase;
-  MoveStack *cur, *end, *endQuiets, *endBadCaptures;
-  MoveStack moves[MAX_MOVES];
+  Value threshold;
+  Depth depth;
+  ExtMove moves[MAX_MOVES];
 };
 
-#endif // !defined(MOVEPICK_H_INCLUDED)
+#endif // #ifndef MOVEPICK_H_INCLUDED