2008-08-31 23:59:13 -06:00
|
|
|
/*
|
2008-10-19 10:56:28 -06:00
|
|
|
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
|
|
|
|
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
|
2016-01-02 02:43:25 -07:00
|
|
|
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
|
2018-11-19 03:18:21 -07:00
|
|
|
Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
|
2008-10-25 08:57:19 -06:00
|
|
|
|
2008-10-19 10:56:28 -06:00
|
|
|
Stockfish is free software: you can redistribute it and/or modify
|
2008-08-31 23:59:13 -06:00
|
|
|
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.
|
2008-10-25 08:57:19 -06:00
|
|
|
|
2008-10-19 10:56:28 -06:00
|
|
|
Stockfish is distributed in the hope that it will be useful,
|
2008-08-31 23:59:13 -06:00
|
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
|
GNU General Public License for more details.
|
2008-10-25 08:57:19 -06:00
|
|
|
|
2008-08-31 23:59:13 -06:00
|
|
|
You should have received a copy of the GNU General Public License
|
|
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
*/
|
|
|
|
|
2013-07-23 07:31:57 -06:00
|
|
|
#ifndef MOVEPICK_H_INCLUDED
|
2008-08-31 23:59:13 -06:00
|
|
|
#define MOVEPICK_H_INCLUDED
|
|
|
|
|
2017-05-26 00:42:50 -06:00
|
|
|
#include <array>
|
2017-11-03 05:37:11 -06:00
|
|
|
#include <limits>
|
2018-03-03 03:29:29 -07:00
|
|
|
#include <type_traits>
|
2013-02-02 09:13:33 -07:00
|
|
|
|
2013-02-03 01:52:39 -07:00
|
|
|
#include "movegen.h"
|
2008-08-31 23:59:13 -06:00
|
|
|
#include "position.h"
|
2011-02-23 13:27:22 -07:00
|
|
|
#include "types.h"
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2018-03-03 03:29:29 -07:00
|
|
|
/// 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.
|
2018-04-23 00:45:50 -06:00
|
|
|
template<typename T, int D>
|
2018-03-03 03:29:29 -07:00
|
|
|
class StatsEntry {
|
2012-01-21 15:32:48 -07:00
|
|
|
|
2018-03-03 03:29:29 -07:00
|
|
|
T entry;
|
2017-11-03 05:37:11 -06:00
|
|
|
|
2018-03-03 03:29:29 -07:00
|
|
|
public:
|
|
|
|
void operator=(const T& v) { entry = v; }
|
2018-07-28 07:33:39 -06:00
|
|
|
T* operator&() { return &entry; }
|
|
|
|
T* operator->() { return &entry; }
|
|
|
|
operator const T&() const { return entry; }
|
2017-11-03 05:37:11 -06:00
|
|
|
|
2018-03-03 03:29:29 -07:00
|
|
|
void operator<<(int bonus) {
|
2018-07-28 07:33:39 -06:00
|
|
|
assert(abs(bonus) <= D); // Ensure range is [-D, D]
|
2018-04-28 22:48:18 -06:00
|
|
|
static_assert(D <= std::numeric_limits<T>::max(), "D overflows T");
|
2017-11-03 05:37:11 -06:00
|
|
|
|
2018-04-23 00:45:50 -06:00
|
|
|
entry += bonus - entry * abs(bonus) / D;
|
2017-11-03 05:37:11 -06:00
|
|
|
|
2018-04-23 00:45:50 -06:00
|
|
|
assert(abs(entry) <= D);
|
2017-11-03 05:37:11 -06:00
|
|
|
}
|
|
|
|
};
|
|
|
|
|
2018-03-03 03:29:29 -07:00
|
|
|
/// Stats is a generic N-dimensional array used to store various statistics.
|
2018-04-23 00:45:50 -06:00
|
|
|
/// 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 <typename T, int D, int Size, int... Sizes>
|
|
|
|
struct Stats : public std::array<Stats<T, D, Sizes...>, Size>
|
2018-03-03 03:29:29 -07:00
|
|
|
{
|
2018-07-28 07:33:39 -06:00
|
|
|
typedef Stats<T, D, Size, Sizes...> stats;
|
2017-11-03 05:37:11 -06:00
|
|
|
|
2018-03-03 03:29:29 -07:00
|
|
|
void fill(const T& v) {
|
2018-07-28 07:33:39 -06:00
|
|
|
|
|
|
|
// For standard-layout 'this' points to first struct member
|
|
|
|
assert(std::is_standard_layout<stats>::value);
|
|
|
|
|
|
|
|
typedef StatsEntry<T, D> entry;
|
|
|
|
entry* p = reinterpret_cast<entry*>(this);
|
|
|
|
std::fill(p, p + sizeof(*this) / sizeof(entry), v);
|
2017-05-26 00:42:50 -06:00
|
|
|
}
|
2017-01-10 00:47:56 -07:00
|
|
|
};
|
|
|
|
|
2018-04-23 00:45:50 -06:00
|
|
|
template <typename T, int D, int Size>
|
2018-07-28 07:33:39 -06:00
|
|
|
struct Stats<T, D, Size> : public std::array<StatsEntry<T, D>, Size> {};
|
2013-02-02 08:04:41 -07:00
|
|
|
|
2018-04-23 00:45:50 -06:00
|
|
|
/// In stats table, D=0 means that the template parameter is not used
|
|
|
|
enum StatsParams { NOT_USED = 0 };
|
|
|
|
|
2017-11-03 05:37:11 -06:00
|
|
|
|
2018-03-03 03:29:29 -07:00
|
|
|
/// 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
|
2019-01-01 06:10:26 -07:00
|
|
|
/// the move's from and to squares, see www.chessprogramming.org/Butterfly_Boards
|
2018-07-25 10:01:47 -06:00
|
|
|
typedef Stats<int16_t, 10692, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
|
2017-11-03 05:37:11 -06:00
|
|
|
|
2017-06-30 09:20:00 -06:00
|
|
|
/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
|
2019-01-01 06:10:26 -07:00
|
|
|
/// move, see www.chessprogramming.org/Countermove_Heuristic
|
2018-04-23 00:45:50 -06:00
|
|
|
typedef Stats<Move, NOT_USED, PIECE_NB, SQUARE_NB> CounterMoveHistory;
|
2018-03-03 03:29:29 -07:00
|
|
|
|
|
|
|
/// CapturePieceToHistory is addressed by a move's [piece][to][captured piece type]
|
2018-07-25 10:01:47 -06:00
|
|
|
typedef Stats<int16_t, 10692, PIECE_NB, SQUARE_NB, PIECE_TYPE_NB> CapturePieceToHistory;
|
2018-03-03 03:29:29 -07:00
|
|
|
|
|
|
|
/// PieceToHistory is like ButterflyHistory but is addressed by a move's [piece][to]
|
2018-04-23 00:45:50 -06:00
|
|
|
typedef Stats<int16_t, 29952, PIECE_NB, SQUARE_NB> PieceToHistory;
|
2017-05-26 00:42:50 -06:00
|
|
|
|
2018-03-03 03:29:29 -07:00
|
|
|
/// 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.
|
2018-04-23 00:45:50 -06:00
|
|
|
typedef Stats<PieceToHistory, NOT_USED, PIECE_NB, SQUARE_NB> ContinuationHistory;
|
2013-05-12 14:21:46 -06:00
|
|
|
|
2016-09-17 00:19:06 -06:00
|
|
|
|
2012-01-21 15:32:48 -07:00
|
|
|
/// 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.
|
2018-03-27 08:44:47 -06:00
|
|
|
class MovePicker {
|
2008-08-31 23:59:13 -06:00
|
|
|
|
2018-03-27 08:44:47 -06:00
|
|
|
enum PickType { Next, Best };
|
2018-03-18 17:56:19 -06:00
|
|
|
|
2008-08-31 23:59:13 -06:00
|
|
|
public:
|
2015-01-21 05:18:19 -07:00
|
|
|
MovePicker(const MovePicker&) = delete;
|
|
|
|
MovePicker& operator=(const MovePicker&) = delete;
|
2017-11-03 05:37:11 -06:00
|
|
|
MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
|
Drop the lever condition for backwards
We can view the patch version as adding some "undermining bonus" for
level pawns, when the defending side can not easily avoid the exchange
by advancing her pawn.
• Case 1) White b2,c3, Black a3,b3:
Black is breaking through, b2 deserves a penalty
• Case 2) White b2,c3, Black a3,c4:
if b2xa3 then White ends up with a weak pawn on a3
and probably a weak pawn on c3 too.
In either case, White can still not safely play b2-b3 and make a
phalanx with c3, which is the essence of a backward pawn definition.
Passed STC in SPRT[0, 4]:
LLR: -2.96 (-2.94,2.94) [0.00,4.00]
Total: 131169 W: 26523 L: 26199 D: 78447
http://tests.stockfishchess.org/tests/view/5aefa4d50ebc5902a409a151
ELO 1.19 [-0.38,2.88] (95%)
Passed LTC in SPRT[-3, 1]:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 24824 W: 3732 L: 3617 D: 17475
http://tests.stockfishchess.org/tests/view/5af04d3f0ebc5902a88b2e55
ELO 1.27 [-1.21,3.70] (95%)
Closes https://github.com/official-stockfish/Stockfish/pull/1584
How to continue from there?
There were some promising tests a couple of months ago about adding
a lever condition for king danger in evaluate.cpp, maybe it would
be time to re-try this after all the recent changes in pawns.cpp
Bench: 4773882
2018-05-08 03:00:51 -06:00
|
|
|
MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
|
|
|
|
const CapturePieceToHistory*,
|
2018-07-19 10:26:05 -06:00
|
|
|
const PieceToHistory**,
|
Drop the lever condition for backwards
We can view the patch version as adding some "undermining bonus" for
level pawns, when the defending side can not easily avoid the exchange
by advancing her pawn.
• Case 1) White b2,c3, Black a3,b3:
Black is breaking through, b2 deserves a penalty
• Case 2) White b2,c3, Black a3,c4:
if b2xa3 then White ends up with a weak pawn on a3
and probably a weak pawn on c3 too.
In either case, White can still not safely play b2-b3 and make a
phalanx with c3, which is the essence of a backward pawn definition.
Passed STC in SPRT[0, 4]:
LLR: -2.96 (-2.94,2.94) [0.00,4.00]
Total: 131169 W: 26523 L: 26199 D: 78447
http://tests.stockfishchess.org/tests/view/5aefa4d50ebc5902a409a151
ELO 1.19 [-0.38,2.88] (95%)
Passed LTC in SPRT[-3, 1]:
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 24824 W: 3732 L: 3617 D: 17475
http://tests.stockfishchess.org/tests/view/5af04d3f0ebc5902a88b2e55
ELO 1.27 [-1.21,3.70] (95%)
Closes https://github.com/official-stockfish/Stockfish/pull/1584
How to continue from there?
There were some promising tests a couple of months ago about adding
a lever condition for king danger in evaluate.cpp, maybe it would
be time to re-try this after all the recent changes in pawns.cpp
Bench: 4773882
2018-05-08 03:00:51 -06:00
|
|
|
Square);
|
|
|
|
MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
|
|
|
|
const CapturePieceToHistory*,
|
|
|
|
const PieceToHistory**,
|
|
|
|
Move,
|
|
|
|
Move*);
|
2017-03-18 16:41:55 -06:00
|
|
|
Move next_move(bool skipQuiets = false);
|
2008-08-31 23:59:13 -06:00
|
|
|
|
|
|
|
private:
|
2018-03-27 08:44:47 -06:00
|
|
|
template<PickType T, typename Pred> Move select(Pred);
|
2013-02-03 01:52:39 -07:00
|
|
|
template<GenType> void score();
|
2016-09-10 13:37:36 -06:00
|
|
|
ExtMove* begin() { return cur; }
|
2015-01-31 11:53:19 -07:00
|
|
|
ExtMove* end() { return endMoves; }
|
2008-10-25 08:57:19 -06:00
|
|
|
|
|
|
|
const Position& pos;
|
2017-06-30 09:20:00 -06:00
|
|
|
const ButterflyHistory* mainHistory;
|
2017-11-03 05:37:11 -06:00
|
|
|
const CapturePieceToHistory* captureHistory;
|
2018-07-19 10:26:05 -06:00
|
|
|
const PieceToHistory** continuationHistory;
|
2018-03-20 18:48:31 -06:00
|
|
|
Move ttMove;
|
|
|
|
ExtMove refutations[3], *cur, *endMoves, *endBadCaptures;
|
2017-06-30 09:20:00 -06:00
|
|
|
int stage;
|
2011-06-12 00:25:51 -06:00
|
|
|
Square recaptureSquare;
|
2015-07-19 03:25:14 -06:00
|
|
|
Value threshold;
|
2017-06-30 09:20:00 -06:00
|
|
|
Depth depth;
|
2016-09-10 13:37:36 -06:00
|
|
|
ExtMove moves[MAX_MOVES];
|
2008-08-31 23:59:13 -06:00
|
|
|
};
|
|
|
|
|
2013-07-23 07:31:57 -06:00
|
|
|
#endif // #ifndef MOVEPICK_H_INCLUDED
|