X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmovepick.h;h=b6e5620e5e333bd9a782ff70fe967a81dfc3c8c0;hb=3d6995eae8039b2bf4141cbc02d87d5a6c2a1905;hp=fe9e5a7c08ab31f1b58882354054515e49688dd9;hpb=148490f04cbd21afd9b01431ee7c947ac0bf78a8;p=stockfish
diff --git a/src/movepick.h b/src/movepick.h
index fe9e5a7c..b6e5620e 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) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, 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
@@ -17,51 +18,89 @@
along with this program. If not, see .
*/
-#if !defined MOVEPICK_H_INCLUDED
+#ifndef MOVEPICK_H_INCLUDED
#define MOVEPICK_H_INCLUDED
-#include // For std::max
-#include // For memset
+#include
+#include
+#include
#include "movegen.h"
#include "position.h"
-#include "search.h"
#include "types.h"
+/// StatsEntry stores the stat table value. It is usually a number but could
+/// be a move or even a nested history. We use a class instead of naked value
+/// to directly call history update operator<<() on the entry so to use stats
+/// tables at caller sites as simple multi-dim arrays.
+template
+class StatsEntry {
-/// The Stats struct stores moves statistics. According to the template parameter
-/// the class can store History, Gains 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. Gains records the move's
-/// best evaluation gain from one ply to the next and is used for pruning decisions.
-/// Countermoves store the move that refute a previous one. Entries are stored
-/// according only to moving piece and destination square, hence two moves with
-/// different origin but same destination and piece will be considered identical.
-template
-struct Stats {
+ static const bool IsInt = std::is_integral::value;
+ typedef typename std::conditional::type TT;
- static const Value Max = Value(2000);
+ T entry;
- const T* operator[](Piece p) const { return &table[p][0]; }
- void clear() { memset(table, 0, sizeof(table)); }
+public:
+ T* get() { return &entry; }
+ void operator=(const T& v) { entry = v; }
+ operator TT() const { return entry; }
- void update(Piece p, Square to, Move m) { table[p][to] = m; }
- void update(Piece p, Square to, Value v) {
+ void operator<<(int bonus) {
+ assert(abs(bonus) <= D); // Ensure range is [-D, D]
+ static_assert(D <= std::numeric_limits::max(), "D overflows T");
- if (Gain)
- table[p][to] = std::max(v, table[p][to] - 1);
+ entry += bonus - entry * abs(bonus) / D;
- else if (abs(table[p][to] + v) < Max)
- table[p][to] += v;
+ assert(abs(entry) <= D);
}
+};
-private:
- T table[PIECE_NB][SQUARE_NB];
+/// Stats is a generic N-dimensional array used to store various statistics.
+/// The first template parameter T is the base type of the array, the second
+/// template parameter D limits the range of updates in [-D, D] when we update
+/// values with the << operator, while the last parameters (Size and Sizes)
+/// encode the dimensions of the array.
+template
+struct Stats : public std::array, Size>
+{
+ T* get() { return this->at(0).get(); }
+
+ void fill(const T& v) {
+ T* p = get();
+ std::fill(p, p + sizeof(*this) / sizeof(*p), v);
+ }
};
-typedef Stats< true, Value> GainsStats;
-typedef Stats HistoryStats;
-typedef Stats CountermovesStats;
+template
+struct Stats : public std::array, Size> {
+ T* get() { return this->at(0).get(); }
+};
+
+/// In stats table, D=0 means that the template parameter is not used
+enum StatsParams { NOT_USED = 0 };
+
+
+/// 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 2 tables (one for each color) indexed by
+/// the move's from and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards
+typedef Stats ButterflyHistory;
+
+/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
+/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic
+typedef Stats CounterMoveHistory;
+
+/// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type]
+typedef Stats CapturePieceToHistory;
+
+/// PieceToHistory is like ButterflyHistory but is addressed by a move's [piece][to]
+typedef Stats PieceToHistory;
+
+/// ContinuationHistory is the combined history of a given pair of moves, usually
+/// the current one given a previous one. The nested history table is based on
+/// PieceToHistory instead of ButterflyBoards.
+typedef Stats ContinuationHistory;
/// MovePicker class is used to pick one pseudo legal move at a time from the
@@ -70,33 +109,42 @@ typedef Stats CountermovesStats;
/// 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.
-
class MovePicker {
- MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
+ enum PickType { Next, Best };
public:
- MovePicker(const Position&, Move, Depth, const HistoryStats&, Square);
- MovePicker(const Position&, Move, const HistoryStats&, PieceType);
- MovePicker(const Position&, Move, Depth, const HistoryStats&,
- const CountermovesStats&, Search::Stack*, Value);
-
- template Move next_move();
+ MovePicker(const MovePicker&) = delete;
+ MovePicker& operator=(const MovePicker&) = delete;
+ 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:
+ template Move select(Pred);
template void score();
- void generate_next();
+ ExtMove* begin() { return cur; }
+ ExtMove* end() { return endMoves; }
const Position& pos;
- const HistoryStats& history;
- Search::Stack* ss;
- Depth depth;
+ const ButterflyHistory* mainHistory;
+ const CapturePieceToHistory* captureHistory;
+ const PieceToHistory** contHistory;
Move ttMove;
- MoveStack killers[3];
+ ExtMove refutations[3], *cur, *endMoves, *endBadCaptures;
+ int stage;
+ Move move;
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