/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
/// The checkInfo struct is initialized at c'tor time and keeps info used
/// to detect if a move gives check.
class Position;
+class Thread;
struct CheckInfo {
Bitboard dcCandidates;
Bitboard pinned;
Bitboard checkSq[8];
+ Square ksq;
};
Key pawnKey, materialKey;
Value npMaterial[2];
int castleRights, rule50, pliesFromNull;
- Score value;
+ Score psqScore;
Square epSquare;
Key key;
StateInfo* previous;
};
+struct ReducedStateInfo {
+ Key pawnKey, materialKey;
+ Value npMaterial[2];
+ int castleRights, rule50, pliesFromNull;
+ Score psqScore;
+ Square epSquare;
+};
+
/// The position data structure. A position consists of the following data:
///
/// * A counter for detecting 50 move rule draws.
class Position {
-
- // No copy c'tor or assignment operator allowed
- Position(const Position&);
- Position& operator=(const Position&);
-
public:
Position() {}
- Position(const Position& pos, int th) { copy(pos, th); }
- Position(const std::string& fen, bool isChess960, int th);
+ Position(const Position& p) { *this = p; }
+ Position(const Position& p, Thread* t) { *this = p; thisThread = t; }
+ Position(const std::string& f, bool c960, Thread* t) { from_fen(f, c960, t); }
+ void operator=(const Position&);
// Text input/output
- void copy(const Position& pos, int th);
- void from_fen(const std::string& fen, bool isChess960);
+ void from_fen(const std::string& fen, bool isChess960, Thread* th);
const std::string to_fen() const;
void print(Move m = MOVE_NONE) const;
- // The piece on a given square
- Piece piece_on(Square s) const;
- bool square_is_empty(Square s) const;
-
- // Side to move
- Color side_to_move() const;
-
- // Bitboard representation of the position
- Bitboard empty_squares() const;
- Bitboard occupied_squares() const;
- Bitboard pieces(Color c) const;
+ // Position representation
+ Bitboard pieces() const;
Bitboard pieces(PieceType pt) const;
- Bitboard pieces(PieceType pt, Color c) const;
Bitboard pieces(PieceType pt1, PieceType pt2) const;
- Bitboard pieces(PieceType pt1, PieceType pt2, Color c) const;
-
- // Number of pieces of each color and type
- int piece_count(Color c, PieceType pt) const;
-
- // The en passant square
- Square ep_square() const;
-
- // Current king position for each color
+ Bitboard pieces(Color c) const;
+ Bitboard pieces(Color c, PieceType pt) const;
+ Bitboard pieces(Color c, PieceType pt1, PieceType pt2) const;
+ Piece piece_on(Square s) const;
Square king_square(Color c) const;
+ Square ep_square() const;
+ bool is_empty(Square s) const;
+ const Square* piece_list(Color c, PieceType pt) const;
+ int piece_count(Color c, PieceType pt) const;
- // Castling rights
- bool can_castle(CastleRight f) const;
- bool can_castle(Color c) const;
- Square castle_rook_square(CastleRight f) const;
+ // Castling
+ int can_castle(CastleRight f) const;
+ int can_castle(Color c) const;
+ bool castle_impeded(Color c, CastlingSide s) const;
+ Square castle_rook_square(Color c, CastlingSide s) const;
- // Bitboards for pinned pieces and discovered check candidates
+ // Checking
+ bool in_check() const;
+ Bitboard checkers() const;
Bitboard discovered_check_candidates() const;
Bitboard pinned_pieces() const;
- // Checking pieces and under check information
- Bitboard checkers() const;
- bool in_check() const;
-
- // Piece lists
- const Square* piece_list(Color c, PieceType pt) const;
-
- // Information about attacks to or from a given square
+ // Attacks to/from a given square
Bitboard attackers_to(Square s) const;
Bitboard attackers_to(Square s, Bitboard occ) const;
Bitboard attacks_from(Piece p, Square s) const;
// Properties of moves
bool move_gives_check(Move m, const CheckInfo& ci) const;
bool move_attacks_square(Move m, Square s) const;
+ bool move_is_legal(const Move m) const;
bool pl_move_is_legal(Move m, Bitboard pinned) const;
bool is_pseudo_legal(const Move m) const;
bool is_capture(Move m) const;
bool is_capture_or_promotion(Move m) const;
bool is_passed_pawn_push(Move m) const;
-
- // Piece captured with previous moves
+ Piece piece_moved(Move m) const;
PieceType captured_piece_type() const;
- // Information about pawns
+ // Piece specific
bool pawn_is_passed(Color c, Square s) const;
+ bool pawn_on_7th(Color c) const;
+ bool opposite_bishops() const;
+ bool bishop_pair(Color c) const;
// Doing and undoing moves
void do_move(Move m, StateInfo& st);
Key pawn_key() const;
Key material_key() const;
- // Incremental evaluation
- Score value() const;
+ // Incremental piece-square evaluation
+ Score psq_score() const;
+ Score psq_delta(Piece p, Square from, Square to) const;
Value non_pawn_material(Color c) const;
- Score pst_delta(Piece piece, Square from, Square to) const;
-
- // Game termination checks
- bool is_mate() const;
- template<bool SkipRepetition> bool is_draw() const;
-
- // Plies from start position to the beginning of search
- int startpos_ply_counter() const;
// Other properties of the position
- bool opposite_colored_bishops() const;
- bool has_pawn_on_7th(Color c) const;
+ Color side_to_move() const;
+ int startpos_ply_counter() const;
bool is_chess960() const;
-
- // Current thread ID searching on the position
- int thread() const;
-
+ Thread* this_thread() const;
int64_t nodes_searched() const;
void set_nodes_searched(int64_t n);
+ template<bool SkipRepetition> bool is_draw() const;
// Position consistency check, for debugging
bool pos_is_ok(int* failedStep = NULL) const;
- void flip_me();
+ void flip();
// Global initialization
static void init();
private:
-
- // Initialization helper functions (used while setting up a position)
+ // Initialization helpers (used while setting up a position)
void clear();
void put_piece(Piece p, Square s);
- void set_castle_right(Square ksq, Square rsq);
- bool move_is_legal(const Move m) const;
+ void set_castle_right(Color c, Square rfrom);
// Helper template functions
template<bool Do> void do_castle_move(Move m);
Key compute_material_key() const;
// Computing incremental evaluation scores and material counts
- Score pst(Piece p, Square s) const;
- Score compute_value() const;
+ Score compute_psq_score() const;
Value compute_non_pawn_material(Color c) const;
- // Board
+ // Board and pieces
Piece board[64]; // [square]
-
- // Bitboards
Bitboard byTypeBB[8]; // [pieceType]
Bitboard byColorBB[2]; // [color]
- Bitboard occupied;
-
- // Piece counts
int pieceCount[2][8]; // [color][pieceType]
-
- // Piece lists
Square pieceList[2][8][16]; // [color][pieceType][index]
int index[64]; // [square]
// Other info
- int castleRightsMask[64]; // [square]
- Square castleRookSquare[16]; // [castleRight]
+ int castleRightsMask[64]; // [square]
+ Square castleRookSquare[2][2]; // [color][side]
+ Bitboard castlePath[2][2]; // [color][side]
StateInfo startState;
int64_t nodes;
int startPosPly;
Color sideToMove;
- int threadID;
+ Thread* thisThread;
StateInfo* st;
int chess960;
// Static variables
static Score pieceSquareTable[16][64]; // [piece][square]
static Key zobrist[2][8][64]; // [color][pieceType][square]/[piece count]
- static Key zobEp[64]; // [square]
+ static Key zobEp[8]; // [file]
static Key zobCastle[16]; // [castleRight]
static Key zobSideToMove;
static Key zobExclusion;
return board[s];
}
-inline bool Position::square_is_empty(Square s) const {
- return board[s] == PIECE_NONE;
+inline Piece Position::piece_moved(Move m) const {
+ return board[from_sq(m)];
}
-inline Color Position::side_to_move() const {
- return sideToMove;
+inline bool Position::is_empty(Square s) const {
+ return board[s] == NO_PIECE;
}
-inline Bitboard Position::occupied_squares() const {
- return occupied;
-}
-
-inline Bitboard Position::empty_squares() const {
- return ~occupied;
+inline Color Position::side_to_move() const {
+ return sideToMove;
}
-inline Bitboard Position::pieces(Color c) const {
- return byColorBB[c];
+inline Bitboard Position::pieces() const {
+ return byTypeBB[ALL_PIECES];
}
inline Bitboard Position::pieces(PieceType pt) const {
return byTypeBB[pt];
}
-inline Bitboard Position::pieces(PieceType pt, Color c) const {
- return byTypeBB[pt] & byColorBB[c];
-}
-
inline Bitboard Position::pieces(PieceType pt1, PieceType pt2) const {
return byTypeBB[pt1] | byTypeBB[pt2];
}
-inline Bitboard Position::pieces(PieceType pt1, PieceType pt2, Color c) const {
- return (byTypeBB[pt1] | byTypeBB[pt2]) & byColorBB[c];
+inline Bitboard Position::pieces(Color c) const {
+ return byColorBB[c];
+}
+
+inline Bitboard Position::pieces(Color c, PieceType pt) const {
+ return byColorBB[c] & byTypeBB[pt];
+}
+
+inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
+ return byColorBB[c] & (byTypeBB[pt1] | byTypeBB[pt2]);
}
inline int Position::piece_count(Color c, PieceType pt) const {
return pieceList[c][KING][0];
}
-inline bool Position::can_castle(CastleRight f) const {
+inline int Position::can_castle(CastleRight f) const {
return st->castleRights & f;
}
-inline bool Position::can_castle(Color c) const {
- return st->castleRights & ((WHITE_OO | WHITE_OOO) << c);
+inline int Position::can_castle(Color c) const {
+ return st->castleRights & ((WHITE_OO | WHITE_OOO) << (2 * c));
}
-inline Square Position::castle_rook_square(CastleRight f) const {
- return castleRookSquare[f];
+inline bool Position::castle_impeded(Color c, CastlingSide s) const {
+ return byTypeBB[ALL_PIECES] & castlePath[c][s];
}
-template<>
-inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
- return StepAttacksBB[make_piece(c, PAWN)][s];
+inline Square Position::castle_rook_square(Color c, CastlingSide s) const {
+ return castleRookSquare[c][s];
}
-template<PieceType Piece> // Knight and King and white pawns
+template<PieceType Pt>
inline Bitboard Position::attacks_from(Square s) const {
- return StepAttacksBB[Piece][s];
-}
-template<>
-inline Bitboard Position::attacks_from<BISHOP>(Square s) const {
- return bishop_attacks_bb(s, occupied_squares());
+ return Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, pieces())
+ : Pt == QUEEN ? attacks_from<ROOK>(s) | attacks_from<BISHOP>(s)
+ : StepAttacksBB[Pt][s];
}
template<>
-inline Bitboard Position::attacks_from<ROOK>(Square s) const {
- return rook_attacks_bb(s, occupied_squares());
-}
-
-template<>
-inline Bitboard Position::attacks_from<QUEEN>(Square s) const {
- return attacks_from<ROOK>(s) | attacks_from<BISHOP>(s);
+inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
+ return StepAttacksBB[make_piece(c, PAWN)][s];
}
inline Bitboard Position::attacks_from(Piece p, Square s) const {
- return attacks_from(p, s, occupied_squares());
+ return attacks_from(p, s, byTypeBB[ALL_PIECES]);
}
inline Bitboard Position::attackers_to(Square s) const {
- return attackers_to(s, occupied_squares());
+ return attackers_to(s, byTypeBB[ALL_PIECES]);
}
inline Bitboard Position::checkers() const {
}
inline bool Position::pawn_is_passed(Color c, Square s) const {
- return !(pieces(PAWN, flip(c)) & passed_pawn_mask(c, s));
+ return !(pieces(~c, PAWN) & passed_pawn_mask(c, s));
}
inline Key Position::key() const {
return st->materialKey;
}
-inline Score Position::pst(Piece p, Square s) const {
- return pieceSquareTable[p][s];
+inline Score Position::psq_delta(Piece p, Square from, Square to) const {
+ return pieceSquareTable[p][to] - pieceSquareTable[p][from];
}
-inline Score Position::pst_delta(Piece piece, Square from, Square to) const {
- return pieceSquareTable[piece][to] - pieceSquareTable[piece][from];
-}
-
-inline Score Position::value() const {
- return st->value;
+inline Score Position::psq_score() const {
+ return st->psqScore;
}
inline Value Position::non_pawn_material(Color c) const {
inline bool Position::is_passed_pawn_push(Move m) const {
- return board[move_from(m)] == make_piece(sideToMove, PAWN)
- && pawn_is_passed(sideToMove, move_to(m));
+ return type_of(piece_moved(m)) == PAWN
+ && pawn_is_passed(sideToMove, to_sq(m));
}
inline int Position::startpos_ply_counter() const {
return startPosPly + st->pliesFromNull; // HACK
}
-inline bool Position::opposite_colored_bishops() const {
+inline bool Position::opposite_bishops() const {
return pieceCount[WHITE][BISHOP] == 1
&& pieceCount[BLACK][BISHOP] == 1
&& opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
}
-inline bool Position::has_pawn_on_7th(Color c) const {
- return pieces(PAWN, c) & rank_bb(relative_rank(c, RANK_7));
+inline bool Position::bishop_pair(Color c) const {
+
+ return pieceCount[c][BISHOP] >= 2
+ && opposite_colors(pieceList[c][BISHOP][0], pieceList[c][BISHOP][1]);
+}
+
+inline bool Position::pawn_on_7th(Color c) const {
+ return pieces(c, PAWN) & rank_bb(relative_rank(c, RANK_7));
}
inline bool Position::is_chess960() const {
inline bool Position::is_capture_or_promotion(Move m) const {
assert(is_ok(m));
- return is_special(m) ? !is_castle(m) : !square_is_empty(move_to(m));
+ return is_special(m) ? !is_castle(m) : !is_empty(to_sq(m));
}
inline bool Position::is_capture(Move m) const {
// Note that castle is coded as "king captures the rook"
assert(is_ok(m));
- return (!square_is_empty(move_to(m)) && !is_castle(m)) || is_enpassant(m);
+ return (!is_empty(to_sq(m)) && !is_castle(m)) || is_enpassant(m);
}
inline PieceType Position::captured_piece_type() const {
return st->capturedType;
}
-inline int Position::thread() const {
- return threadID;
+inline Thread* Position::this_thread() const {
+ return thisThread;
}
#endif // !defined(POSITION_H_INCLUDED)
projects / stockfish / blobdiff