2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
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
34 // Maximum number of allowed moves per position
35 const int MOVES_MAX = 256;
43 /// A move needs 16 bits to be stored
45 /// bit 0- 5: destination square (from 0 to 63)
46 /// bit 6-11: origin square (from 0 to 63)
47 /// bit 12-13: promotion piece type - 2 (from KNIGHT-2 to QUEEN-2)
48 /// bit 14-15: special move flag: promotion (1), en passant (2), castle (3)
50 /// Special cases are MOVE_NONE and MOVE_NULL. We can sneak these in
51 /// because in any normal move destination square is always different
52 /// from origin square while MOVE_NONE and MOVE_NULL have the same
53 /// origin and destination square, 0 and 1 respectively.
66 inline bool operator<(const MoveStack& f, const MoveStack& s) { return f.score < s.score; }
68 // An helper insertion sort implementation, works with pointers and iterators
69 template<typename T, typename K>
70 inline void insertion_sort(K firstMove, K lastMove)
75 if (firstMove != lastMove)
76 for (cur = firstMove + 1; cur != lastMove; cur++)
83 while (--d != firstMove && *--p < value);
89 // Our dedicated sort in range [firstMove, lastMove), first splits
90 // positive scores from ramining then order seaprately the two sets.
92 inline void sort_moves(T* firstMove, T* lastMove, T** lastPositive)
100 d->score = -1; // right guard
102 // Split positives vs non-positives
104 while ((++p)->score > 0) {}
108 while (--d != p && d->score <= 0) {}
117 // Sort just positive scored moves, remaining only when we get there
118 insertion_sort<T, T*>(firstMove, p);
122 // Picks up the best move in range [curMove, lastMove), one per cycle.
123 // It is faster then sorting all the moves in advance when moves are few,
124 // as normally are the possible captures. Note that is not a stable alghoritm.
126 inline T pick_best(T* curMove, T* lastMove)
131 while (++curMove != lastMove)
133 if (bestMove < *curMove)
144 //// Inline functions
147 inline Square move_from(Move m) {
148 return Square((int(m) >> 6) & 0x3F);
151 inline Square move_to(Move m) {
152 return Square(m & 0x3F);
155 inline bool move_is_special(Move m) {
156 return m & (3 << 14);
159 inline bool move_is_promotion(Move m) {
160 return (m & (3 << 14)) == (1 << 14);
163 inline int move_is_ep(Move m) {
164 return (m & (3 << 14)) == (2 << 14);
167 inline int move_is_castle(Move m) {
168 return (m & (3 << 14)) == (3 << 14);
171 inline bool move_is_short_castle(Move m) {
172 return move_is_castle(m) && (move_to(m) > move_from(m));
175 inline bool move_is_long_castle(Move m) {
176 return move_is_castle(m) && (move_to(m) < move_from(m));
179 inline PieceType move_promotion_piece(Move m) {
180 return move_is_promotion(m) ? PieceType(((int(m) >> 12) & 3) + 2) : PIECE_TYPE_NONE;
183 inline Move make_move(Square from, Square to) {
184 return Move(int(to) | (int(from) << 6));
187 inline Move make_promotion_move(Square from, Square to, PieceType promotion) {
188 return Move(int(to) | (int(from) << 6) | ((int(promotion) - 2) << 12) | (1 << 14));
191 inline Move make_ep_move(Square from, Square to) {
192 return Move(int(to) | (int(from) << 6) | (2 << 14));
195 inline Move make_castle_move(Square from, Square to) {
196 return Move(int(to) | (int(from) << 6) | (3 << 14));
204 extern std::ostream& operator<<(std::ostream& os, Move m);
205 extern Move move_from_uci(const Position& pos, const std::string &str);
206 extern const std::string move_to_uci(Move m, bool chess960);
207 extern bool move_is_ok(Move m);
209 #endif // !defined(MOVE_H_INCLUDED)