Removes a few Bitboards and functions

No longer used

closes https://github.com/official-stockfish/Stockfish/pull/4695

No functional change

src/bitboard.h

@@ -32,9 +32,6 @@ std::string pretty(Bitboard b);
 
 } // namespace Stockfish::Bitboards
 
-constexpr Bitboard AllSquares = ~Bitboard(0);
-constexpr Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;
-
 constexpr Bitboard FileABB = 0x0101010101010101ULL;
 constexpr Bitboard FileBBB = FileABB << 1;
 constexpr Bitboard FileCBB = FileABB << 2;
@@ -53,17 +50,6 @@ constexpr Bitboard Rank6BB = Rank1BB << (8 * 5);
 constexpr Bitboard Rank7BB = Rank1BB << (8 * 6);
 constexpr Bitboard Rank8BB = Rank1BB << (8 * 7);
 
-constexpr Bitboard QueenSide   = FileABB | FileBBB | FileCBB | FileDBB;
-constexpr Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
-constexpr Bitboard KingSide    = FileEBB | FileFBB | FileGBB | FileHBB;
-constexpr Bitboard Center      = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
-
-constexpr Bitboard KingFlank[FILE_NB] = {
-  QueenSide ^ FileDBB, QueenSide, QueenSide,
-  CenterFiles, CenterFiles,
-  KingSide, KingSide, KingSide ^ FileEBB
-};
-
 extern uint8_t PopCnt16[1 << 16];
 extern uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
 
@@ -124,11 +110,6 @@ constexpr bool more_than_one(Bitboard b) {
 }
 
 
-constexpr bool opposite_colors(Square s1, Square s2) {
-  return (s1 + rank_of(s1) + s2 + rank_of(s2)) & 1;
-}
-
-
 /// rank_bb() and file_bb() return a bitboard representing all the squares on
 /// the given file or rank.
 
@@ -177,25 +158,6 @@ inline Bitboard pawn_attacks_bb(Color c, Square s) {
   return PawnAttacks[c][s];
 }
 
-
-/// pawn_double_attacks_bb() returns the squares doubly attacked by pawns of the
-/// given color from the squares in the given bitboard.
-
-template<Color C>
-constexpr Bitboard pawn_double_attacks_bb(Bitboard b) {
-  return C == WHITE ? shift<NORTH_WEST>(b) & shift<NORTH_EAST>(b)
-                    : shift<SOUTH_WEST>(b) & shift<SOUTH_EAST>(b);
-}
-
-
-/// adjacent_files_bb() returns a bitboard representing all the squares on the
-/// adjacent files of a given square.
-
-constexpr Bitboard adjacent_files_bb(Square s) {
-  return shift<EAST>(file_bb(s)) | shift<WEST>(file_bb(s));
-}
-
-
 /// line_bb() returns a bitboard representing an entire line (from board edge
 /// to board edge) that intersects the two given squares. If the given squares
 /// are not on a same file/rank/diagonal, the function returns 0. For instance,
@@ -234,32 +196,6 @@ constexpr Bitboard forward_ranks_bb(Color c, Square s) {
                     : ~Rank8BB >> 8 * relative_rank(BLACK, s);
 }
 
-
-/// forward_file_bb() returns a bitboard representing all the squares along the
-/// line in front of the given one, from the point of view of the given color.
-
-constexpr Bitboard forward_file_bb(Color c, Square s) {
-  return forward_ranks_bb(c, s) & file_bb(s);
-}
-
-
-/// pawn_attack_span() returns a bitboard representing all the squares that can
-/// be attacked by a pawn of the given color when it moves along its file, starting
-/// from the given square.
-
-constexpr Bitboard pawn_attack_span(Color c, Square s) {
-  return forward_ranks_bb(c, s) & adjacent_files_bb(s);
-}
-
-
-/// passed_pawn_span() returns a bitboard which can be used to test if a pawn of
-/// the given color and on the given square is a passed pawn.
-
-constexpr Bitboard passed_pawn_span(Color c, Square s) {
-  return pawn_attack_span(c, s) | forward_file_bb(c, s);
-}
-
-
 /// aligned() returns true if the squares s1, s2 and s3 are aligned either on a
 /// straight or on a diagonal line.
 
@@ -277,8 +213,6 @@ template<> inline int distance<Rank>(Square x, Square y) { return std::abs(rank_
 template<> inline int distance<Square>(Square x, Square y) { return SquareDistance[x][y]; }
 
 inline int edge_distance(File f) { return std::min(f, File(FILE_H - f)); }
-inline int edge_distance(Rank r) { return std::min(r, Rank(RANK_8 - r)); }
-
 
 /// attacks_bb(Square) returns the pseudo attacks of the give piece type
 /// assuming an empty board.
@@ -430,14 +364,6 @@ inline Square pop_lsb(Bitboard& b) {
   return s;
 }
 
-
-/// frontmost_sq() returns the most advanced square for the given color,
-/// requires a non-zero bitboard.
-inline Square frontmost_sq(Color c, Bitboard b) {
-  assert(b);
-  return c == WHITE ? msb(b) : lsb(b);
-}
-
 } // namespace Stockfish
 
 #endif // #ifndef BITBOARD_H_INCLUDED

src/position.h

@@ -100,7 +100,6 @@ public:
   template<PieceType Pt> int count(Color c) const;
   template<PieceType Pt> int count() const;
   template<PieceType Pt> Square square(Color c) const;
-  bool is_on_semiopen_file(Color c, Square s) const;
 
   // Castling
   CastlingRights castling_rights(Color c) const;
@@ -129,11 +128,6 @@ public:
   Piece moved_piece(Move m) const;
   Piece captured_piece() const;
 
-  // Piece specific
-  bool pawn_passed(Color c, Square s) const;
-  bool opposite_bishops() const;
-  int  pawns_on_same_color_squares(Color c, Square s) const;
-
   // Doing and undoing moves
   void do_move(Move m, StateInfo& newSt);
   void do_move(Move m, StateInfo& newSt, bool givesCheck);
@@ -149,7 +143,6 @@ public:
   Key key() const;
   Key key_after(Move m) const;
   Key material_key() const;
-  Key pawn_key() const;
 
   // Other properties of the position
   Color side_to_move() const;
@@ -160,7 +153,6 @@ public:
   bool has_game_cycle(int ply) const;
   bool has_repeated() const;
   int rule50_count() const;
-  Score psq_score() const;
   Value psq_eg_stm() const;
   Value non_pawn_material(Color c) const;
   Value non_pawn_material() const;
@@ -258,10 +250,6 @@ inline Square Position::ep_square() const {
   return st->epSquare;
 }
 
-inline bool Position::is_on_semiopen_file(Color c, Square s) const {
-  return !(pieces(c, PAWN) & file_bb(s));
-}
-
 inline bool Position::can_castle(CastlingRights cr) const {
   return st->castlingRights & cr;
 }
@@ -318,14 +306,6 @@ inline Bitboard Position::check_squares(PieceType pt) const {
   return st->checkSquares[pt];
 }
 
-inline bool Position::pawn_passed(Color c, Square s) const {
-  return !(pieces(~c, PAWN) & passed_pawn_span(c, s));
-}
-
-inline int Position::pawns_on_same_color_squares(Color c, Square s) const {
-  return popcount(pieces(c, PAWN) & ((DarkSquares & s) ? DarkSquares : ~DarkSquares));
-}
-
 inline Key Position::key() const {
   return adjust_key50<false>(st->key);
 }
@@ -341,10 +321,6 @@ inline Key Position::material_key() const {
   return st->materialKey;
 }
 
-inline Score Position::psq_score() const {
-  return psq;
-}
-
 inline Value Position::psq_eg_stm() const {
   return (sideToMove == WHITE ? 1 : -1) * eg_value(psq);
 }
@@ -365,12 +341,6 @@ inline int Position::rule50_count() const {
   return st->rule50;
 }
 
-inline bool Position::opposite_bishops() const {
-  return   count<BISHOP>(WHITE) == 1
-        && count<BISHOP>(BLACK) == 1
-        && opposite_colors(square<BISHOP>(WHITE), square<BISHOP>(BLACK));
-}
-
 inline bool Position::is_chess960() const {
   return chess960;
 }