diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 072ca427..cd4bf920 100644 --- a/src/bitboard.cpp +++ b/src/bitboard.cpp @@ -53,10 +53,13 @@ const std::string Bitboards::pretty(Bitboard b) void Bitboards::init() { - for (unsigned i = 0; i < (1 << 16); ++i) PopCnt16[i] = (uint8_t)std::bitset<16>(i).count(); for (Square s = SQ_BEGIN; s < SQ_END; ++s) SquareBB[s] = (1UL << s); + + for (Square s1 = SQ_A1; s1 <= SQ_C8; ++s1) + for (Square s2 = SQ_A1; s2 <= SQ_C8; ++s2) + SquareDistance[s1][s2] = std::max(distance(s1, s2), distance(s1, s2)); } diff --git a/src/bitboard.h b/src/bitboard.h index f7165db3..a1513c0d 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -16,21 +16,13 @@ along with this program. If not, see . */ -#ifndef BITBOARD_H -#define BITBOARD_H +#ifndef BITBOARD_H_INCLUDED +#define BITBOARD_H_INCLUDED #include #include "types.h" -namespace Bitbases -{ - -void init(); -bool probe(Square wksq, Square wpsq, Square bksq, Color us); - -} - namespace Bitboards { @@ -42,34 +34,18 @@ const std::string pretty(Bitboard b); constexpr Bitboard AllSquares = ~Bitboard(0); //constexpr Bitboard starSquares12 = 0xAA55AA55AA55AA55UL; // TODO -constexpr Bitboard FileABB = 0xE0000000; -constexpr Bitboard FileBBB = 0x00E00000; -constexpr Bitboard FileCBB = 0x0000E000; -constexpr Bitboard FileDBB = 0x11111100; -constexpr Bitboard FileEBB = 0x00000E00; -constexpr Bitboard FileFBB = 0x000E0000; -constexpr Bitboard FileGBB = 0x0E000000; +constexpr Bitboard FileABB = 0x0000FF00; +constexpr Bitboard FileBBB = FileABB << (8 * 1); +constexpr Bitboard FileCBB = FileABB << (8 * 2); -constexpr Bitboard Rank1BB = 0x38000000; -constexpr Bitboard Rank2BB = 0x00380000; -constexpr Bitboard Rank3BB = 0x00003800; -constexpr Bitboard Rank4BB = 0x44444400; -constexpr Bitboard Rank5BB = 0x00008300; -constexpr Bitboard Rank6BB = 0x00830000; -constexpr Bitboard Rank7BB = 0x83000000; - -constexpr Bitboard Ring1 = 0xFF00; -constexpr Bitboard Ring2 = Ring1 << (8 * 1); -constexpr Bitboard Ring3 = Ring1 << (8 * 2); - -constexpr Bitboard Seat1 = 0x01010100; -constexpr Bitboard Seat2 = Seat1 << 1; -constexpr Bitboard Seat3 = Seat1 << 2; -constexpr Bitboard Seat4 = Seat1 << 3; -constexpr Bitboard Seat5 = Seat1 << 4; -constexpr Bitboard Seat6 = Seat1 << 5; -constexpr Bitboard Seat7 = Seat1 << 6; -constexpr Bitboard Seat8 = Seat1 << 7; +constexpr Bitboard Rank1BB = 0x01010100; +constexpr Bitboard Rank2BB = Rank1BB << 1; +constexpr Bitboard Rank3BB = Rank1BB << 2; +constexpr Bitboard Rank4BB = Rank1BB << 3; +constexpr Bitboard Rank5BB = Rank1BB << 4; +constexpr Bitboard Rank6BB = Rank1BB << 5; +constexpr Bitboard Rank7BB = Rank1BB << 6; +constexpr Bitboard Rank8BB = Rank1BB << 7; extern uint8_t PopCnt16[1 << 16]; extern uint8_t SquareDistance[SQ_32][SQ_32]; @@ -77,12 +53,17 @@ extern uint8_t SquareDistance[SQ_32][SQ_32]; extern Bitboard SquareBB[SQ_32]; extern Bitboard LineBB[EFFECTIVE_SQUARE_NB][SQ_32]; +// TODO +const Bitboard Star9 = SquareBB[17] | SquareBB[19] | SquareBB[21] | SquareBB[23]; +const Bitboard Star12 = SquareBB[16] | SquareBB[18] | SquareBB[20] | SquareBB[22]; + inline Bitboard square_bb(Square s) { assert(SQ_BEGIN <= s && s < SQ_END); return SquareBB[s]; } + /// Overloads of bitwise operators between a Bitboard and a Square for testing /// whether a given bit is set in a bitboard, and for setting and clearing bits. @@ -90,35 +71,59 @@ inline Bitboard operator&(Bitboard b, Square s) { return b & square_bb(s); } + inline Bitboard operator|(Bitboard b, Square s) { return b | square_bb(s); } + inline Bitboard operator^(Bitboard b, Square s) { return b ^ square_bb(s); } + inline Bitboard &operator|=(Bitboard &b, Square s) { return b |= square_bb(s); } + inline Bitboard &operator^=(Bitboard &b, Square s) { return b ^= square_bb(s); } +inline Bitboard operator&(Square s, Bitboard b) +{ + return b & s; +} + +inline Bitboard operator|(Square s, Bitboard b) +{ + return b | s; +} + +inline Bitboard operator^(Square s, Bitboard b) +{ + return b ^ s; +} + +inline Bitboard operator|(Square s1, Square s2) +{ + return square_bb(s1) | s2; +} + constexpr bool more_than_one(Bitboard b) { return b & (b - 1); } -# if 0 + /// rank_bb() and file_bb() return a bitboard representing all the squares on /// the given file or rank. inline Bitboard rank_bb(Rank r) { - return Rank1BB << (8 * r); + return Rank1BB << (r - 1); } inline Bitboard rank_bb(Square s) @@ -128,131 +133,64 @@ inline Bitboard rank_bb(Square s) inline Bitboard file_bb(File f) { - return FileABB << f; + return FileABB << (f - 1); } inline Bitboard file_bb(Square s) { return file_bb(file_of(s)); } -#endif - -inline Bitboard ring_bb(File file) -{ - return Ring1 << (8 * (file - 1)); -} - -inline Bitboard seat_bb(Rank rank) -{ - return Seat1 << (rank - 1); -} - -#if 0 -/// shift() moves a bitboard one step along direction D - -template -constexpr Bitboard shift(Bitboard b) -{ - return D == NORTH ? b << 8 : D == SOUTH ? b >> 8 - : D == NORTH + NORTH ? b << 16 : D == SOUTH + SOUTH ? b >> 16 - : D == EAST ? (b & ~FileHBB) << 1 : D == WEST ? (b & ~FileABB) >> 1 - : D == NORTH_EAST ? (b & ~FileHBB) << 9 : D == NORTH_WEST ? (b & ~FileABB) << 7 - : D == SOUTH_EAST ? (b & ~FileHBB) >> 7 : D == SOUTH_WEST ? (b & ~FileABB) >> 9 - : 0; -} - - -/// adjacent_files_bb() returns a bitboard representing all the squares on the -/// adjacent files of the given one. - -inline Bitboard adjacent_files_bb(Square s) -{ - return shift(file_bb(s)) | shift(file_bb(s)); -} - - -/// between_bb() returns squares that are linearly between the given squares -/// If the given squares are not on a same file/rank/diagonal, return 0. - -inline Bitboard between_bb(Square s1, Square s2) -{ - return LineBB[s1][s2] & ((AllSquares << (s1 + (s1 < s2))) - ^ (AllSquares << (s2 + !(s1 < 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_12_R1S5_D3) will return the 16 squares on ranks 1 and 2. - -inline Bitboard forward_ranks_bb(Color c, Square 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. - -inline Bitboard forward_file_bb(Color c, Square s) -{ - return forward_ranks_bb(c, s) & file_bb(s); -} - - -/// aligned() returns true if the squares s1, s2 and s3 are aligned either on a -/// straight or on a diagonal line. - -inline bool aligned(Square s1, Square s2, Square s3) -{ - return LineBB[s1][s2] & s3; -} - /// distance() functions return the distance between x and y, defined as the /// number of steps for a king in x to reach y. template inline int distance(Square x, Square y); + template<> inline int distance(Square x, Square y) { return std::abs(file_of(x) - file_of(y)); } + template<> inline int distance(Square x, Square y) { return std::abs(rank_of(x) - rank_of(y)); } + template<> inline int distance(Square x, Square y) { return SquareDistance[x][y]; } -template constexpr const T &clamp(const T &v, const T &lo, const T &hi) +inline int edge_distance(File f) { - return v < lo ? lo : v > hi ? hi : v; + return std::min(f, File(FILE_C - f)); +} + +inline int edge_distance(Rank r) +{ + return std::min(r, Rank(RANK_8 - r)); } -#endif /// popcount() counts the number of non-zero bits in a bitboard inline int popcount(Bitboard b) { - #ifndef USE_POPCNT union { - Bitboard bb; uint16_t u[4]; + Bitboard bb; uint16_t u[2]; } v = { b }; - return PopCnt16[v.u[0]] + PopCnt16[v.u[1]] + PopCnt16[v.u[2]] + PopCnt16[v.u[3]]; + + return PopCnt16[v.u[0]] + PopCnt16[v.u[1]]; #elif defined(_MSC_VER) || defined(__INTEL_COMPILER) - return (int)_mm_popcnt_u64(b); + return (int)_mm_popcnt_u32(b); #else // Assumed gcc or compatible compiler - return __builtin_popcountll(b); + return __builtin_popcount(b); #endif } @@ -265,13 +203,13 @@ inline int popcount(Bitboard b) inline Square lsb(Bitboard b) { assert(b); - return Square(__builtin_ctzll(b)); + return Square(__builtin_ctz(b)); } inline Square msb(Bitboard b) { assert(b); - return Square(63 ^ __builtin_clzll(b)); + return Square(31 ^ __builtin_clz(b)); } #elif defined(_MSC_VER) // MSVC @@ -282,7 +220,7 @@ inline Square lsb(Bitboard b) { assert(b); unsigned long idx; - _BitScanForward64(&idx, b); + _BitScanForward(&idx, b); return (Square)idx; } @@ -290,7 +228,7 @@ inline Square msb(Bitboard b) { assert(b); unsigned long idx; - _BitScanReverse64(&idx, b); + _BitScanReverse(&idx, b); return (Square)idx; } @@ -343,10 +281,11 @@ inline Square pop_lsb(Bitboard *b) } -/// frontmost_sq() returns the most advanced square for the given color +/// frontmost_sq() returns the most advanced square for the given color, +/// requires a non-zero bitboard. inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); } -#endif // BITBOARD_H +#endif // #ifndef BITBOARD_H_INCLUDED