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
28 // Maximum number of allowed moves per position
29 const int MOVES_MAX = 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((int(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 bool move_is_short_castle(Move m) {
157 return move_is_castle(m) && (move_to(m) > move_from(m));
160 inline bool move_is_long_castle(Move m) {
161 return move_is_castle(m) && (move_to(m) < move_from(m));
164 inline PieceType move_promotion_piece(Move m) {
165 return move_is_promotion(m) ? PieceType(((int(m) >> 12) & 3) + 2) : PIECE_TYPE_NONE;
168 inline Move make_move(Square from, Square to) {
169 return Move(int(to) | (int(from) << 6));
172 inline Move make_promotion_move(Square from, Square to, PieceType promotion) {
173 return Move(int(to) | (int(from) << 6) | ((int(promotion) - 2) << 12) | (1 << 14));
176 inline Move make_ep_move(Square from, Square to) {
177 return Move(int(to) | (int(from) << 6) | (2 << 14));
180 inline Move make_castle_move(Square from, Square to) {
181 return Move(int(to) | (int(from) << 6) | (3 << 14));
184 inline bool move_is_ok(Move m) {
185 return move_from(m) != move_to(m); // Catches also MOVE_NONE
188 #endif // !defined(MOVE_H_INCLUDED)