X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitboard.h;h=dee73b4b3f70285016e601032cd4ed65738f65a8;hb=fce4cc1829f25fd52c5dd637ab54d867eec065fb;hp=29d8f66d41525533a8602c469b0f749920bd4c7f;hpb=5f1843c9cb55afcd3fb1da9e9dc4b0092f25d9f0;p=stockfish diff --git a/src/bitboard.h b/src/bitboard.h index 29d8f66d..dee73b4b 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -1,6 +1,6 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file) + Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file) Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -19,26 +19,23 @@ #ifndef BITBOARD_H_INCLUDED #define BITBOARD_H_INCLUDED +#include +#include +#include +#include +#include #include #include "types.h" -namespace Bitbases { - -void init(); -bool probe(Square wksq, Square wpsq, Square bksq, Color us); - -} +namespace Stockfish { namespace Bitboards { void init(); -const std::string pretty(Bitboard b); - -} +std::string pretty(Bitboard b); -constexpr Bitboard AllSquares = ~Bitboard(0); -constexpr Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL; +} // namespace Stockfish::Bitboards constexpr Bitboard FileABB = 0x0101010101010101ULL; constexpr Bitboard FileBBB = FileABB << 1; @@ -58,21 +55,10 @@ 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]; -extern Bitboard SquareBB[SQUARE_NB]; +extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB]; extern Bitboard LineBB[SQUARE_NB][SQUARE_NB]; extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB]; extern Bitboard PawnAttacks[COLOR_NB][SQUARE_NB]; @@ -105,7 +91,7 @@ extern Magic BishopMagics[SQUARE_NB]; inline Bitboard square_bb(Square s) { assert(is_ok(s)); - return SquareBB[s]; + return (1ULL << s); } @@ -129,11 +115,6 @@ 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. @@ -182,25 +163,6 @@ 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 -constexpr Bitboard pawn_double_attacks_bb(Bitboard b) { - return C == WHITE ? shift(b) & shift(b) - : shift(b) & shift(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(file_bb(s)) | shift(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, @@ -209,56 +171,26 @@ constexpr Bitboard adjacent_files_bb(Square s) { inline Bitboard line_bb(Square s1, Square s2) { assert(is_ok(s1) && is_ok(s2)); + return LineBB[s1][s2]; } -/// between_bb() returns a bitboard representing squares that are linearly -/// between the two given squares (excluding the given squares). If the given -/// squares are not on a same file/rank/diagonal, we return 0. For instance, -/// between_bb(SQ_C4, SQ_F7) will return a bitboard with squares D5 and E6. +/// between_bb(s1, s2) returns a bitboard representing the squares in the semi-open +/// segment between the squares s1 and s2 (excluding s1 but including s2). If the +/// given squares are not on a same file/rank/diagonal, it returns s2. For instance, +/// between_bb(SQ_C4, SQ_F7) will return a bitboard with squares D5, E6 and F7, but +/// between_bb(SQ_E6, SQ_F8) will return a bitboard with the square F8. This trick +/// allows to generate non-king evasion moves faster: the defending piece must either +/// interpose itself to cover the check or capture the checking piece. inline Bitboard between_bb(Square s1, Square s2) { - Bitboard b = line_bb(s1, s2) & ((AllSquares << s1) ^ (AllSquares << s2)); - return b & (b - 1); //exclude lsb -} + assert(is_ok(s1) && is_ok(s2)); -/// 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. - -constexpr Bitboard forward_ranks_bb(Color c, Square s) { - return c == WHITE ? ~Rank1BB << 8 * relative_rank(WHITE, 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); + return BetweenBB[s1][s2]; } - /// aligned() returns true if the squares s1, s2 and s3 are aligned either on a /// straight or on a diagonal line. @@ -276,8 +208,6 @@ template<> inline int distance(Square x, Square y) { return std::abs(rank_ template<> inline int distance(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. @@ -332,9 +262,9 @@ inline int popcount(Bitboard b) { 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]]; -#elif defined(_MSC_VER) || defined(__INTEL_COMPILER) +#elif defined(_MSC_VER) - return (int)_mm_popcnt_u64(b); + return int(_mm_popcnt_u64(b)); #else // Assumed gcc or compatible compiler @@ -346,7 +276,7 @@ inline int popcount(Bitboard b) { /// lsb() and msb() return the least/most significant bit in a non-zero bitboard -#if defined(__GNUC__) // GCC, Clang, ICC +#if defined(__GNUC__) // GCC, Clang, ICX inline Square lsb(Bitboard b) { assert(b); @@ -412,22 +342,23 @@ inline Square msb(Bitboard b) { #endif +/// least_significant_square_bb() returns the bitboard of the least significant +/// square of a non-zero bitboard. It is equivalent to square_bb(lsb(bb)). -/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard - -inline Square pop_lsb(Bitboard* b) { - assert(*b); - const Square s = lsb(*b); - *b &= *b - 1; - return s; +inline Bitboard least_significant_square_bb(Bitboard b) { + assert(b); + return b & -b; } +/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard -/// frontmost_sq() returns the most advanced square for the given color, -/// requires a non-zero bitboard. -inline Square frontmost_sq(Color c, Bitboard b) { +inline Square pop_lsb(Bitboard& b) { assert(b); - return c == WHITE ? msb(b) : lsb(b); + const Square s = lsb(b); + b &= b - 1; + return s; } +} // namespace Stockfish + #endif // #ifndef BITBOARD_H_INCLUDED