X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.h;h=af7b592ad564cb5a3af85ca97173d5259e390484;hp=8fa774818db69b71c34d5e357ce722dd7cdab1b6;hb=1aab5b4b055dffae5e2a2cf9958d3d0d79f66cb4;hpb=dd4796fcd5559847d4b8aab7d21ffff9929799ce diff --git a/src/bitboard.h b/src/bitboard.h index 8fa77481..af7b592a 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -60,15 +60,21 @@ constexpr Bitboard Rank6BB = Rank1BB << (8 * 5); constexpr Bitboard Rank7BB = Rank1BB << (8 * 6); constexpr Bitboard Rank8BB = Rank1BB << (8 * 7); -extern int8_t SquareDistance[SQUARE_NB][SQUARE_NB]; +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); + +extern uint8_t PopCnt16[1 << 16]; +extern uint8_t SquareDistance[SQUARE_NB][SQUARE_NB]; extern Bitboard SquareBB[SQUARE_NB]; -extern Bitboard ForwardRanksBB[COLOR_NB][RANK_NB]; extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB]; extern Bitboard LineBB[SQUARE_NB][SQUARE_NB]; extern Bitboard DistanceRingBB[SQUARE_NB][8]; extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB]; extern Bitboard PawnAttacks[COLOR_NB][SQUARE_NB]; +extern Bitboard KingFlank[FILE_NB]; /// Magic holds all magic bitboards relevant data for a single square @@ -133,6 +139,7 @@ inline bool opposite_colors(Square s1, Square s2) { return bool(DarkSquares & s1) != bool(DarkSquares & s2); } + /// rank_bb() and file_bb() return a bitboard representing all the squares on /// the given file or rank. @@ -153,7 +160,7 @@ inline Bitboard file_bb(Square s) { } -/// shift() moves a bitboard one step along direction D (mainly for pawns) +/// shift() moves a bitboard one step along direction D template constexpr Bitboard shift(Bitboard b) { @@ -165,8 +172,8 @@ constexpr Bitboard shift(Bitboard b) { } -/// pawn_attacks_bb() returns the pawn attacks for the given color from the -/// squares in the given bitboard. +/// pawn_attacks_bb() returns the squares attacked by pawns of the given color +/// from the squares in the given bitboard. template constexpr Bitboard pawn_attacks_bb(Bitboard b) { @@ -175,11 +182,11 @@ constexpr Bitboard pawn_attacks_bb(Bitboard b) { } -/// double_pawn_attacks_bb() returns the pawn attacks for the given color -/// from the squares in the given bitboard. +/// pawn_double_attacks_bb() returns the squares doubly attacked by pawns of the +/// given color from the squares in the given bitboard. template -constexpr Bitboard double_pawn_attacks_bb(Bitboard b) { +constexpr Bitboard pawn_double_attacks_bb(Bitboard b) { return C == WHITE ? shift(b) & shift(b) : shift(b) & shift(b); } @@ -192,48 +199,49 @@ inline Bitboard adjacent_files_bb(File f) { return shift(file_bb(f)) | shift(file_bb(f)); } + /// between_bb() returns a bitboard representing all the squares between the two /// given ones. For instance, between_bb(SQ_C4, SQ_F7) returns a bitboard with -/// the bits for square d5 and e6 set. If s1 and s2 are not on the same rank, file -/// or diagonal, 0 is returned. +/// the bits for square d5 and e6 set. If s1 and s2 are not on the same rank, +/// file or diagonal, 0 is returned. inline Bitboard between_bb(Square s1, Square s2) { return BetweenBB[s1][s2]; } -/// forward_ranks_bb() returns a bitboard representing the squares on all the ranks +/// forward_ranks_bb() returns a bitboard representing the squares on the ranks /// in front of the given one, from the point of view of the given color. For instance, /// forward_ranks_bb(BLACK, SQ_D3) will return the 16 squares on ranks 1 and 2. inline Bitboard forward_ranks_bb(Color c, Square s) { - return ForwardRanksBB[c][rank_of(s)]; + return c == WHITE ? ~Rank1BB << 8 * (rank_of(s) - RANK_1) + : ~Rank8BB >> 8 * (RANK_8 - rank_of(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: -/// ForwardFileBB[c][s] = forward_ranks_bb(c, s) & file_bb(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. inline Bitboard forward_file_bb(Color c, Square s) { - return ForwardRanksBB[c][rank_of(s)] & file_bb(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: +/// 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. inline Bitboard pawn_attack_span(Color c, Square s) { return forward_ranks_bb(c, s) & adjacent_files_bb(file_of(s)); } -/// passed_pawn_mask() returns a bitboard mask which can be used to test if a -/// pawn of the given color and on the given square is a passed pawn: +/// 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. -inline Bitboard passed_pawn_mask(Color c, Square s) { - return pawn_attack_span(c, s) | forward_file_bb(c, s); +inline Bitboard passed_pawn_span(Color c, Square s) { + return forward_ranks_bb(c, s) & (adjacent_files_bb(file_of(s)) | file_bb(s)); } @@ -248,7 +256,7 @@ inline bool aligned(Square s1, Square s2, Square s3) { /// distance() functions return the distance between x and y, defined as the /// number of steps for a king in x to reach y. Works with squares, ranks, files. -template inline int distance(T x, T y) { return x < y ? y - x : x - y; } +template inline int distance(T x, T y) { return std::abs(x - y); } template<> inline int distance(Square x, Square y) { return SquareDistance[x][y]; } template inline int distance(T2 x, T2 y); @@ -286,7 +294,6 @@ inline int popcount(Bitboard b) { #ifndef USE_POPCNT - extern uint8_t PopCnt16[1 << 16]; union { Bitboard bb; uint16_t u[4]; } v = { b }; return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]];