2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2009 Marco Costalba
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #if !defined(MOVE_H_INCLUDED)
22 #define MOVE_H_INCLUDED
41 /// A move needs 17 bits to be stored
43 /// bit 0- 5: destination square (from 0 to 63)
44 /// bit 6-11: origin square (from 0 to 63)
45 /// bit 12-14: promotion piece type
46 /// bit 15: en passant flag
47 /// bit 16: castle flag
49 /// Special cases are MOVE_NONE and MOVE_NULL. We can sneak these in
50 /// because in any normal move destination square is always different
51 /// from origin square while MOVE_NONE and MOVE_NULL have the same
52 /// origin and destination square, 0 and 1 respectively.
65 // Note that operator< is set up such that sorting will be in descending order
66 inline bool operator<(const MoveStack& f, const MoveStack& s) { return s.score < f.score; }
68 // An helper insertion sort implementation
70 inline void insertion_sort(T* firstMove, T* lastMove)
75 if (firstMove != lastMove)
76 for (cur = firstMove + 1; cur != lastMove; cur++)
83 while (--d != firstMove && value < *--p);
89 // Our dedicated sort in range [firstMove, lastMove), it is well
90 // tuned for non-captures where we have a lot of zero scored moves.
92 inline void sort_moves(T* firstMove, T* lastMove)
100 d->score = -1; // right guard
102 // Split positives vs non-positives
104 while ((++p)->score > 0);
108 while (--d != p && d->score <= 0);
118 insertion_sort<T>(firstMove, p);
123 // Split zero vs negatives
125 while ((++p)->score == 0);
129 while (--d != p && d->score < 0);
139 insertion_sort<T>(p, lastMove);
142 // Picks up the best move in range [curMove, lastMove), one per cycle.
143 // It is faster then sorting all the moves in advance when moves are few,
144 // as normally are the possible captures. Note that is not a stable alghoritm.
146 inline T pick_best(T* curMove, T* lastMove)
151 while (++curMove != lastMove)
153 if (*curMove < bestMove)
164 //// Inline functions
167 inline Square move_from(Move m) {
168 return Square((int(m) >> 6) & 0x3F);
171 inline Square move_to(Move m) {
172 return Square(m & 0x3F);
175 inline PieceType move_promotion_piece(Move m) {
176 return PieceType((int(m) >> 12) & 7);
179 inline int move_is_special(Move m) {
180 return m & (0x1F << 12);
183 inline int move_is_promotion(Move m) {
184 return m & (7 << 12);
187 inline int move_is_ep(Move m) {
188 return m & (1 << 15);
191 inline int move_is_castle(Move m) {
192 return m & (1 << 16);
195 inline bool move_is_short_castle(Move m) {
196 return move_is_castle(m) && (move_to(m) > move_from(m));
199 inline bool move_is_long_castle(Move m) {
200 return move_is_castle(m) && (move_to(m) < move_from(m));
203 inline Move make_promotion_move(Square from, Square to, PieceType promotion) {
204 return Move(int(to) | (int(from) << 6) | (int(promotion) << 12));
207 inline Move make_move(Square from, Square to) {
208 return Move(int(to) | (int(from) << 6));
211 inline Move make_castle_move(Square from, Square to) {
212 return Move(int(to) | (int(from) << 6) | (1 << 16));
215 inline Move make_ep_move(Square from, Square to) {
216 return Move(int(to) | (int(from) << 6) | (1 << 15));
224 extern std::ostream& operator<<(std::ostream &os, Move m);
225 extern Move move_from_string(const Position &pos, const std::string &str);
226 extern const std::string move_to_string(Move m);
227 extern bool move_is_ok(Move m);
230 #endif // !defined(MOVE_H_INCLUDED)