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/>.
20 #if !defined(MOVE_H_INCLUDED)
21 #define MOVE_H_INCLUDED
28 // Maximum number of allowed moves per position
29 const int MAX_MOVES = 256;
31 /// A move needs 16 bits to be stored
33 /// bit 0- 5: destination square (from 0 to 63)
34 /// bit 6-11: origin square (from 0 to 63)
35 /// bit 12-13: promotion piece type - 2 (from KNIGHT-2 to QUEEN-2)
36 /// bit 14-15: special move flag: promotion (1), en passant (2), castle (3)
38 /// Special cases are MOVE_NONE and MOVE_NULL. We can sneak these in
39 /// because in any normal move destination square is always different
40 /// from origin square while MOVE_NONE and MOVE_NULL have the same
41 /// origin and destination square, 0 and 1 respectively.
54 inline bool operator<(const MoveStack& f, const MoveStack& s) { return f.score < s.score; }
56 // An helper insertion sort implementation, works with pointers and iterators
57 template<typename T, typename K>
58 inline void insertion_sort(K firstMove, K lastMove)
63 if (firstMove != lastMove)
64 for (cur = firstMove + 1; cur != lastMove; cur++)
71 while (--d != firstMove && *--p < value);
77 // Our dedicated sort in range [firstMove, lastMove), first splits
78 // positive scores from ramining then order seaprately the two sets.
80 inline void sort_moves(T* firstMove, T* lastMove, T** lastPositive)
88 d->score = -1; // right guard
90 // Split positives vs non-positives
92 while ((++p)->score > 0) {}
96 while (--d != p && d->score <= 0) {}
105 // Sort just positive scored moves, remaining only when we get there
106 insertion_sort<T, T*>(firstMove, p);
110 // Picks up the best move in range [curMove, lastMove), one per cycle.
111 // It is faster then sorting all the moves in advance when moves are few,
112 // as normally are the possible captures. Note that is not a stable alghoritm.
114 inline T pick_best(T* curMove, T* lastMove)
119 while (++curMove != lastMove)
121 if (bestMove < *curMove)
132 inline Square move_from(Move m) {
133 return Square((m >> 6) & 0x3F);
136 inline Square move_to(Move m) {
137 return Square(m & 0x3F);
140 inline bool move_is_special(Move m) {
141 return m & (3 << 14);
144 inline bool move_is_promotion(Move m) {
145 return (m & (3 << 14)) == (1 << 14);
148 inline int move_is_ep(Move m) {
149 return (m & (3 << 14)) == (2 << 14);
152 inline int move_is_castle(Move m) {
153 return (m & (3 << 14)) == (3 << 14);
156 inline PieceType promotion_piece_type(Move m) {
157 return PieceType(((m >> 12) & 3) + 2);
160 inline Move make_move(Square from, Square to) {
161 return Move(to | (from << 6));
164 inline Move make_promotion_move(Square from, Square to, PieceType promotion) {
165 return Move(to | (from << 6) | (1 << 14) | ((promotion - 2) << 12)) ;
168 inline Move make_ep_move(Square from, Square to) {
169 return Move(to | (from << 6) | (2 << 14));
172 inline Move make_castle_move(Square from, Square to) {
173 return Move(to | (from << 6) | (3 << 14));
176 inline bool move_is_ok(Move m) {
177 return move_from(m) != move_to(m); // Catches also MOVE_NONE
182 extern const std::string move_to_uci(Move m, bool chess960);
183 extern Move move_from_uci(const Position& pos, const std::string& str);
184 extern const std::string move_to_san(Position& pos, Move m);
185 extern const std::string pretty_pv(Position& pos, int depth, Value score, int time, Move pv[]);
187 #endif // !defined(MOVE_H_INCLUDED)