/*
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
#include <cassert>
#include "bitboard.h"
-#include "move.h"
#include "types.h"
-/// Maximum number of plies per game (220 should be enough, because the
-/// maximum search depth is 100, and during position setup we reset the
-/// move counter for every non-reversible move).
-const int MaxGameLength = 220;
-
/// The checkInfo struct is initialized at c'tor time and keeps info used
/// to detect if a move gives check.
+class Position;
struct CheckInfo {
- explicit CheckInfo(const Position&);
+ explicit CheckInfo(const Position&);
- Bitboard dcCandidates;
- Bitboard pinned;
- Bitboard checkSq[8];
+ Bitboard dcCandidates;
+ Bitboard pinned;
+ Bitboard checkSq[8];
+ Square ksq;
};
/// object to its previous state when we retract a move. Whenever a move
/// is made on the board (by calling Position::do_move), an StateInfo object
/// must be passed as a parameter.
-class Position;
struct StateInfo {
Key pawnKey, materialKey;
- int castleRights, rule50, gamePly, pliesFromNull;
- Square epSquare;
- Score value;
Value npMaterial[2];
+ int castleRights, rule50, pliesFromNull;
+ Score value;
+ Square epSquare;
Key key;
Bitboard checkersBB;
class Position {
- Position(); // No default or copy c'tor allowed
- Position(const Position& pos);
+ // No copy c'tor or assignment operator allowed
+ Position(const Position&);
+ Position& operator=(const Position&);
public:
- Position(const Position& pos, int threadID);
- Position(const std::string& fen, bool isChess960, int threadID);
+ Position() {}
+ Position(const Position& pos, int th) { copy(pos, th); }
+ Position(const std::string& fen, bool isChess960, int th);
// Text input/output
+ void copy(const Position& pos, int th);
void from_fen(const std::string& fen, bool isChess960);
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;
+ Piece piece_moved(Move m) 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;
Bitboard pieces(PieceType pt) const;
// Castling rights
bool can_castle(CastleRight f) const;
bool can_castle(Color c) const;
+ bool castle_impeded(CastleRight f) const;
Square castle_rook_square(CastleRight f) const;
// Bitboards for pinned pieces and discovered check candidates
- Bitboard discovered_check_candidates(Color c) const;
- Bitboard pinned_pieces(Color c) const;
+ Bitboard discovered_check_candidates() const;
+ Bitboard pinned_pieces() const;
// Checking pieces and under check information
Bitboard checkers() const;
template<PieceType> Bitboard attacks_from(Square s, Color c) const;
// Properties of moves
- bool pl_move_is_legal(Move m, Bitboard pinned) const;
- bool move_is_pl(const Move m) const;
bool move_gives_check(Move m, const CheckInfo& ci) const;
- bool move_is_capture(Move m) const;
- bool move_is_capture_or_promotion(Move m) const;
- bool move_is_passed_pawn_push(Move m) const;
bool move_attacks_square(Move m, Square s) 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
PieceType captured_piece_type() const;
bool pawn_is_passed(Color c, Square s) const;
// Doing and undoing moves
- void do_setup_move(Move m);
void do_move(Move m, StateInfo& st);
void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
void undo_move(Move m);
- void do_null_move(StateInfo& st);
- void undo_null_move();
+ template<bool Do> void do_null_move(StateInfo& st);
// Static exchange evaluation
int see(Move m) const;
int see_sign(Move m) const;
// Accessing hash keys
- Key get_key() const;
- Key get_exclusion_key() const;
- Key get_pawn_key() const;
- Key get_material_key() const;
+ Key key() const;
+ Key exclusion_key() const;
+ Key pawn_key() const;
+ Key material_key() const;
// Incremental evaluation
Score value() 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;
+ // Other properties of the position
template<bool SkipRepetition> bool is_draw() const;
-
- // Number of plies from starting position
int startpos_ply_counter() const;
-
- // Other properties of the position
bool opposite_colored_bishops() const;
+ bool both_color_bishops(Color c) const;
bool has_pawn_on_7th(Color c) const;
bool is_chess960() const;
-
- // Current thread ID searching on the position
int thread() const;
-
int64_t nodes_searched() const;
void set_nodes_searched(int64_t n);
// Position consistency check, for debugging
- bool is_ok(int* failedStep = NULL) const;
- void flip();
+ bool pos_is_ok(int* failedStep = NULL) const;
+ void flip_me();
// Global initialization
static void init();
// Initialization helper functions (used while setting up a position)
void clear();
- void detach();
void put_piece(Piece p, Square s);
- void set_castle(int f, Square ksq, Square rsq);
- void set_castling_rights(char token);
+ void set_castle_right(Color c, Square rfrom);
bool move_is_legal(const Move m) const;
- // Helper functions for doing and undoing moves
- void do_capture_move(Key& key, PieceType capture, Color them, Square to, bool ep);
- void do_castle_move(Move m);
- void undo_castle_move(Move m);
-
- template<bool FindPinned>
- Bitboard hidden_checkers(Color c) const;
+ // Helper template functions
+ template<bool Do> void do_castle_move(Move m);
+ template<bool FindPinned> Bitboard hidden_checkers() const;
// Computing hash keys from scratch (for initialization and debugging)
Key compute_key() const;
// Bitboards
Bitboard byTypeBB[8]; // [pieceType]
Bitboard byColorBB[2]; // [color]
+ Bitboard occupied;
// Piece counts
int pieceCount[2][8]; // [color][pieceType]
int index[64]; // [square]
// Other info
- Key history[MaxGameLength];
int castleRightsMask[64]; // [square]
Square castleRookSquare[16]; // [castleRight]
+ Bitboard castlePath[16]; // [castleRight]
StateInfo startState;
int64_t nodes;
+ int startPosPly;
Color sideToMove;
- int fullMoves;
int threadID;
StateInfo* st;
int chess960;
// Static variables
static Score pieceSquareTable[16][64]; // [piece][square]
- static Key zobrist[2][8][64]; // [color][pieceType][square]
- static Key zobEp[64]; // [square]
+ static Key zobrist[2][8][64]; // [color][pieceType][square]/[piece count]
+ static Key zobEp[8]; // [file]
static Key zobCastle[16]; // [castleRight]
static Key zobSideToMove;
static Key zobExclusion;
return board[s];
}
+inline Piece Position::piece_moved(Move m) const {
+ return board[from_sq(m)];
+}
+
inline bool Position::square_is_empty(Square s) const {
- return piece_on(s) == PIECE_NONE;
+ return board[s] == NO_PIECE;
}
inline Color Position::side_to_move() const {
}
inline Bitboard Position::occupied_squares() const {
- return byTypeBB[0];
-}
-
-inline Bitboard Position::empty_squares() const {
- return ~occupied_squares();
+ return occupied;
}
inline Bitboard Position::pieces(Color c) const {
return st->castleRights & ((WHITE_OO | WHITE_OOO) << c);
}
-inline Square Position::castle_rook_square(CastleRight f) const {
- return castleRookSquare[f];
+inline bool Position::castle_impeded(CastleRight f) const {
+ return occupied & castlePath[f];
}
-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(CastleRight f) const {
+ return castleRookSquare[f];
}
-template<PieceType Piece> // Knight and King and white pawns
+template<PieceType Pt>
inline Bitboard Position::attacks_from(Square s) const {
- return StepAttacksBB[Piece][s];
+ return Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, occupied_squares())
+ : Pt == QUEEN ? attacks_from<ROOK>(s) | attacks_from<BISHOP>(s)
+ : StepAttacksBB[Pt][s];
}
template<>
-inline Bitboard Position::attacks_from<BISHOP>(Square s) const {
- return bishop_attacks_bb(s, occupied_squares());
+inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
+ return StepAttacksBB[make_piece(c, PAWN)][s];
}
-template<>
-inline Bitboard Position::attacks_from<ROOK>(Square s) const {
- return rook_attacks_bb(s, occupied_squares());
+inline Bitboard Position::attacks_from(Piece p, Square s) const {
+ return attacks_from(p, s, occupied);
}
-template<>
-inline Bitboard Position::attacks_from<QUEEN>(Square s) const {
- return attacks_from<ROOK>(s) | attacks_from<BISHOP>(s);
+inline Bitboard Position::attackers_to(Square s) const {
+ return attackers_to(s, occupied);
}
inline Bitboard Position::checkers() const {
}
inline bool Position::in_check() const {
- return st->checkersBB != EmptyBoardBB;
+ return st->checkersBB != 0;
+}
+
+inline Bitboard Position::discovered_check_candidates() const {
+ return hidden_checkers<false>();
+}
+
+inline Bitboard Position::pinned_pieces() const {
+ return hidden_checkers<true>();
}
inline bool Position::pawn_is_passed(Color c, Square s) const {
- return !(pieces(PAWN, opposite_color(c)) & passed_pawn_mask(c, s));
+ return !(pieces(PAWN, ~c) & passed_pawn_mask(c, s));
}
-inline Key Position::get_key() const {
+inline Key Position::key() const {
return st->key;
}
-inline Key Position::get_exclusion_key() const {
+inline Key Position::exclusion_key() const {
return st->key ^ zobExclusion;
}
-inline Key Position::get_pawn_key() const {
+inline Key Position::pawn_key() const {
return st->pawnKey;
}
-inline Key Position::get_material_key() const {
+inline Key Position::material_key() const {
return st->materialKey;
}
return st->npMaterial[c];
}
-inline bool Position::move_is_passed_pawn_push(Move m) const {
+inline bool Position::is_passed_pawn_push(Move m) const {
- Color c = side_to_move();
- return piece_on(move_from(m)) == make_piece(c, PAWN)
- && pawn_is_passed(c, move_to(m));
+ return board[from_sq(m)] == make_piece(sideToMove, PAWN)
+ && pawn_is_passed(sideToMove, to_sq(m));
}
inline int Position::startpos_ply_counter() const {
- return Max(2 * (fullMoves - 1), 0) + int(sideToMove == BLACK);
+ return startPosPly + st->pliesFromNull; // HACK
}
inline bool Position::opposite_colored_bishops() const {
- return piece_count(WHITE, BISHOP) == 1
- && piece_count(BLACK, BISHOP) == 1
- && opposite_color_squares(piece_list(WHITE, BISHOP)[0], piece_list(BLACK, BISHOP)[0]);
+ return pieceCount[WHITE][BISHOP] == 1
+ && pieceCount[BLACK][BISHOP] == 1
+ && opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
+}
+
+inline bool Position::both_color_bishops(Color c) const {
+ // Assumes that there are only two bishops
+ return pieceCount[c][BISHOP] >= 2 &&
+ opposite_colors(pieceList[c][BISHOP][0], pieceList[c][BISHOP][1]);
}
inline bool Position::has_pawn_on_7th(Color c) const {
return chess960;
}
-inline bool Position::move_is_capture_or_promotion(Move m) const {
+inline bool Position::is_capture_or_promotion(Move m) const {
- assert(move_is_ok(m));
- return move_is_special(m) ? !move_is_castle(m) : !square_is_empty(move_to(m));
+ assert(is_ok(m));
+ return is_special(m) ? !is_castle(m) : !square_is_empty(to_sq(m));
}
-inline bool Position::move_is_capture(Move m) const {
+inline bool Position::is_capture(Move m) const {
// Note that castle is coded as "king captures the rook"
- assert(move_is_ok(m));
- return (!square_is_empty(move_to(m)) && !move_is_castle(m)) || move_is_ep(m);
+ assert(is_ok(m));
+ return (!square_is_empty(to_sq(m)) && !is_castle(m)) || is_enpassant(m);
}
inline PieceType Position::captured_piece_type() const {
projects / stockfish / blobdiff