/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008 Marco Costalba
+ 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
#if !defined(BITBOARD_H_INCLUDED)
#define BITBOARD_H_INCLUDED
-
-////
-//// Defines
-////
-
-// Comment following define if you prefer manually adjust
-// platform macros defined below
-#define AUTO_CONFIGURATION
-
-// Quiet a warning on Intel compiler
-#if !defined(__SIZEOF_INT__ )
-#define __SIZEOF_INT__ 0
-#endif
-
-// Check for 64 bits for different compilers: Intel, MSVC and gcc
-#if defined(__x86_64) || defined(_WIN64) || (__SIZEOF_INT__ > 4)
-#define IS_64BIT
-#endif
-
-#if !defined(AUTO_CONFIGURATION) || defined(IS_64BIT)
-
-//#define USE_COMPACT_ROOK_ATTACKS
-//#define USE_32BIT_ATTACKS
-#define USE_FOLDED_BITSCAN
-
-#define BITCOUNT_SWAR_64
-//#define BITCOUNT_SWAR_32
-//#define BITCOUNT_LOOP
-
-#else
-
-#define USE_32BIT_ATTACKS
-#define USE_FOLDED_BITSCAN
-#define BITCOUNT_SWAR_32
-
-#endif
-
-////
-//// Includes
-////
-
-#include "direction.h"
-#include "piece.h"
-#include "square.h"
#include "types.h"
+namespace Bitboards {
-////
-//// Types
-////
-
-typedef uint64_t Bitboard;
-
-
-////
-//// Constants and variables
-////
+void init();
+void print(Bitboard b);
-const Bitboard EmptyBoardBB = 0ULL;
-
-const Bitboard WhiteSquaresBB = 0x55AA55AA55AA55AAULL;
-const Bitboard BlackSquaresBB = 0xAA55AA55AA55AA55ULL;
+}
-extern const Bitboard SquaresByColorBB[2];
+namespace Bitbases {
-const Bitboard FileABB = 0x0101010101010101ULL;
-const Bitboard FileBBB = 0x0202020202020202ULL;
-const Bitboard FileCBB = 0x0404040404040404ULL;
-const Bitboard FileDBB = 0x0808080808080808ULL;
-const Bitboard FileEBB = 0x1010101010101010ULL;
-const Bitboard FileFBB = 0x2020202020202020ULL;
-const Bitboard FileGBB = 0x4040404040404040ULL;
-const Bitboard FileHBB = 0x8080808080808080ULL;
+void init_kpk();
+uint32_t probe_kpk(Square wksq, Square wpsq, Square bksq, Color stm);
-extern const Bitboard FileBB[8];
-extern const Bitboard NeighboringFilesBB[8];
-extern const Bitboard ThisAndNeighboringFilesBB[8];
+}
-const Bitboard Rank1BB = 0xFFULL;
-const Bitboard Rank2BB = 0xFF00ULL;
-const Bitboard Rank3BB = 0xFF0000ULL;
-const Bitboard Rank4BB = 0xFF000000ULL;
-const Bitboard Rank5BB = 0xFF00000000ULL;
-const Bitboard Rank6BB = 0xFF0000000000ULL;
-const Bitboard Rank7BB = 0xFF000000000000ULL;
-const Bitboard Rank8BB = 0xFF00000000000000ULL;
+CACHE_LINE_ALIGNMENT
-extern const Bitboard RankBB[8];
-extern const Bitboard RelativeRankBB[2][8];
-extern const Bitboard InFrontBB[2][8];
+extern Bitboard RMasks[64];
+extern Bitboard RMagics[64];
+extern Bitboard* RAttacks[64];
+extern unsigned RShifts[64];
-extern Bitboard SetMaskBB[65];
-extern Bitboard ClearMaskBB[65];
+extern Bitboard BMasks[64];
+extern Bitboard BMagics[64];
+extern Bitboard* BAttacks[64];
+extern unsigned BShifts[64];
-extern Bitboard StepAttackBB[16][64];
-extern Bitboard RayBB[64][8];
+extern Bitboard SquareBB[64];
+extern Bitboard FileBB[8];
+extern Bitboard RankBB[8];
+extern Bitboard AdjacentFilesBB[8];
+extern Bitboard ThisAndAdjacentFilesBB[8];
+extern Bitboard InFrontBB[2][8];
+extern Bitboard StepAttacksBB[16][64];
extern Bitboard BetweenBB[64][64];
-
+extern Bitboard DistanceRingsBB[64][8];
+extern Bitboard ForwardBB[2][64];
extern Bitboard PassedPawnMask[2][64];
-extern Bitboard OutpostMask[2][64];
-
-#if defined(USE_COMPACT_ROOK_ATTACKS)
-extern Bitboard RankAttacks[8][64], FileAttacks[8][64];
-#else
-extern const uint64_t RMult[64];
-extern const int RShift[64];
-extern Bitboard RMask[64];
-extern int RAttackIndex[64];
-extern Bitboard RAttacks[0x19000];
-#endif // defined(USE_COMPACT_ROOK_ATTACKS)
+extern Bitboard AttackSpanMask[2][64];
+extern Bitboard PseudoAttacks[6][64];
-extern const uint64_t BMult[64];
-extern const int BShift[64];
-extern Bitboard BMask[64];
-extern int BAttackIndex[64];
-extern Bitboard BAttacks[0x1480];
-extern Bitboard BishopPseudoAttacks[64];
-extern Bitboard RookPseudoAttacks[64];
-extern Bitboard QueenPseudoAttacks[64];
+/// 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.
+inline Bitboard operator&(Bitboard b, Square s) {
+ return b & SquareBB[s];
+}
-////
-//// Inline functions
-////
+inline Bitboard& operator|=(Bitboard& b, Square s) {
+ return b |= SquareBB[s];
+}
-/// Functions for testing whether a given bit is set in a bitboard, and for
-/// setting and clearing bits.
+inline Bitboard& operator^=(Bitboard& b, Square s) {
+ return b ^= SquareBB[s];
+}
-inline Bitboard bit_is_set(Bitboard b, Square s) {
- return b & SetMaskBB[s];
+inline Bitboard operator|(Bitboard b, Square s) {
+ return b | SquareBB[s];
}
-inline void set_bit(Bitboard *b, Square s) {
- *b |= SetMaskBB[s];
+inline Bitboard operator^(Bitboard b, Square s) {
+ return b ^ SquareBB[s];
}
-inline void clear_bit(Bitboard *b, Square s) {
- *b &= ClearMaskBB[s];
+
+/// more_than_one() returns true if in 'b' there is more than one bit set
+
+inline bool more_than_one(Bitboard b) {
+ return b & (b - 1);
}
-/// rank_bb() and file_bb() gives a bitboard containing all squares on a given
-/// file or rank. It is also possible to pass a square as input to these
-/// functions.
+/// rank_bb() and file_bb() take a file or a square as input and return
+/// a bitboard representing all squares on the given file or rank.
inline Bitboard rank_bb(Rank r) {
return RankBB[r];
}
inline Bitboard rank_bb(Square s) {
- return rank_bb(square_rank(s));
+ return RankBB[rank_of(s)];
}
inline Bitboard file_bb(File f) {
}
inline Bitboard file_bb(Square s) {
- return file_bb(square_file(s));
+ return FileBB[file_of(s)];
}
-/// neighboring_files_bb takes a file or a square as input, and returns a
-/// bitboard representing all squares on the neighboring files.
-
-inline Bitboard neighboring_files_bb(File f) {
- return NeighboringFilesBB[f];
-}
-
-inline Bitboard neighboring_files_bb(Square s) {
- return neighboring_files_bb(square_file(s));
-}
-
-
-/// this_and_neighboring_files_bb takes a file or a square as input, and
-/// returns a bitboard representing all squares on the given and neighboring
-/// files.
-
-inline Bitboard this_and_neighboring_files_bb(File f) {
- return ThisAndNeighboringFilesBB[f];
-}
+/// adjacent_files_bb takes a file as input and returns a bitboard representing
+/// all squares on the adjacent files.
-inline Bitboard this_and_neighboring_files_bb(Square s) {
- return this_and_neighboring_files_bb(square_file(s));
+inline Bitboard adjacent_files_bb(File f) {
+ return AdjacentFilesBB[f];
}
-/// relative_rank_bb() takes a color and a rank as input, and returns a bitboard
-/// representing all squares on the given rank from the given color's point of
-/// view. For instance, relative_rank_bb(WHITE, 7) gives all squares on the
-/// 7th rank, while relative_rank_bb(BLACK, 7) gives all squares on the 2nd
-/// rank.
+/// this_and_adjacent_files_bb takes a file as input and returns a bitboard
+/// representing all squares on the given and adjacent files.
-inline Bitboard relative_rank_bb(Color c, Rank r) {
- return RelativeRankBB[c][r];
+inline Bitboard this_and_adjacent_files_bb(File f) {
+ return ThisAndAdjacentFilesBB[f];
}
}
inline Bitboard in_front_bb(Color c, Square s) {
- return in_front_bb(c, square_rank(s));
+ return InFrontBB[c][rank_of(s)];
}
-/// behind_bb() takes a color and a rank or square as input, and returns a
-/// bitboard representing all the squares on all ranks behind of the rank
-/// (or square), from the given color's point of view.
+/// between_bb returns a bitboard representing all squares between two squares.
+/// 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 line, file or diagonal,
+/// 0 is returned.
-inline Bitboard behind_bb(Color c, Rank r) {
- return InFrontBB[opposite_color(c)][r];
-}
-
-inline Bitboard behind_bb(Color c, Square s) {
- return in_front_bb(opposite_color(c), square_rank(s));
+inline Bitboard between_bb(Square s1, Square s2) {
+ return BetweenBB[s1][s2];
}
-/// ray_bb() gives a bitboard representing all squares along the ray in a
-/// given direction from a given square.
+/// forward_bb takes a color and a square as input, and returns a bitboard
+/// representing all squares along the line in front of the square, from the
+/// point of view of the given color. Definition of the table is:
+/// ForwardBB[c][s] = in_front_bb(c, s) & file_bb(s)
-inline Bitboard ray_bb(Square s, SignedDirection d) {
- return RayBB[s][d];
+inline Bitboard forward_bb(Color c, Square s) {
+ return ForwardBB[c][s];
}
-/// Functions for computing sliding attack bitboards. rook_attacks_bb(),
-/// bishop_attacks_bb() and queen_attacks_bb() all take a square and a
-/// bitboard of occupied squares as input, and return a bitboard representing
-/// all squares attacked by a rook, bishop or queen on the given square.
-
-#if defined(USE_COMPACT_ROOK_ATTACKS)
-
-inline Bitboard file_attacks_bb(Square s, Bitboard blockers) {
- Bitboard b = (blockers >> square_file(s)) & 0x01010101010100ULL;
- return
- FileAttacks[square_rank(s)][(b*0xd6e8802041d0c441ULL)>>58] & file_bb(s);
-}
-
-inline Bitboard rank_attacks_bb(Square s, Bitboard blockers) {
- Bitboard b = (blockers >> ((s & 56) + 1)) & 63;
- return RankAttacks[square_file(s)][b] & rank_bb(s);
-}
+/// passed_pawn_mask takes a color and a square as input, and returns a
+/// bitboard mask which can be used to test if a pawn of the given color on
+/// the given square is a passed pawn. Definition of the table is:
+/// PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_adjacent_files_bb(s)
-inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
- return file_attacks_bb(s, blockers) | rank_attacks_bb(s, blockers);
+inline Bitboard passed_pawn_mask(Color c, Square s) {
+ return PassedPawnMask[c][s];
}
-#elif defined(USE_32BIT_ATTACKS)
-inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
- Bitboard b = blockers & RMask[s];
- return RAttacks[RAttackIndex[s] +
- (unsigned(int(b) * int(RMult[s]) ^
- int(b >> 32) * int(RMult[s] >> 32))
- >> RShift[s])];
-}
+/// attack_span_mask takes a color and a square as input, and returns a bitboard
+/// representing all squares that can be attacked by a pawn of the given color
+/// when it moves along its file starting from the given square. Definition is:
+/// AttackSpanMask[c][s] = in_front_bb(c, s) & adjacent_files_bb(s);
-#else
-
-inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
- Bitboard b = blockers & RMask[s];
- return RAttacks[RAttackIndex[s] + ((b * RMult[s]) >> RShift[s])];
+inline Bitboard attack_span_mask(Color c, Square s) {
+ return AttackSpanMask[c][s];
}
-#endif
-#if defined(USE_32BIT_ATTACKS)
+/// squares_aligned returns true if the squares s1, s2 and s3 are aligned
+/// either on a straight or on a diagonal line.
-inline Bitboard bishop_attacks_bb(Square s, Bitboard blockers) {
- Bitboard b = blockers & BMask[s];
- return BAttacks[BAttackIndex[s] +
- (unsigned(int(b) * int(BMult[s]) ^
- int(b >> 32) * int(BMult[s] >> 32))
- >> BShift[s])];
+inline bool squares_aligned(Square s1, Square s2, Square s3) {
+ return (BetweenBB[s1][s2] | BetweenBB[s1][s3] | BetweenBB[s2][s3])
+ & ( SquareBB[s1] | SquareBB[s2] | SquareBB[s3]);
}
-#else // defined(USE_32BIT_ATTACKS)
-inline Bitboard bishop_attacks_bb(Square s, Bitboard blockers) {
- Bitboard b = blockers & BMask[s];
- return BAttacks[BAttackIndex[s] + ((b * BMult[s]) >> BShift[s])];
-}
-
-#endif // defined(USE_32BIT_ATTACKS)
+/// same_color_squares() returns a bitboard representing all squares with
+/// the same color of the given square.
-inline Bitboard queen_attacks_bb(Square s, Bitboard blockers) {
- return rook_attacks_bb(s, blockers) | bishop_attacks_bb(s, blockers);
+inline Bitboard same_color_squares(Square s) {
+ return Bitboard(0xAA55AA55AA55AA55ULL) & s ? 0xAA55AA55AA55AA55ULL
+ : ~0xAA55AA55AA55AA55ULL;
}
-/// squares_between returns a bitboard representing all squares between
-/// two squares. For instance, squares_between(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 line, file or diagonal, EmptyBoardBB is returned.
+/// Functions for computing sliding attack bitboards. Function attacks_bb() takes
+/// a square and a bitboard of occupied squares as input, and returns a bitboard
+/// representing all squares attacked by Pt (bishop or rook) on the given square.
+template<PieceType Pt>
+FORCE_INLINE unsigned magic_index(Square s, Bitboard occ) {
-inline Bitboard squares_between(Square s1, Square s2) {
- return BetweenBB[s1][s2];
-}
+ Bitboard* const Masks = Pt == ROOK ? RMasks : BMasks;
+ Bitboard* const Magics = Pt == ROOK ? RMagics : BMagics;
+ unsigned* const Shifts = Pt == ROOK ? RShifts : BShifts;
+ if (Is64Bit)
+ return unsigned(((occ & Masks[s]) * Magics[s]) >> Shifts[s]);
-/// squares_in_front_of takes a color and a square as input, and returns a
-/// bitboard representing all squares along the line in front of the square,
-/// from the point of view of the given color. For instance,
-/// squares_in_front_of(BLACK, SQ_E4) returns a bitboard with the squares
-/// e3, e2 and e1 set.
-
-inline Bitboard squares_in_front_of(Color c, Square s) {
- return in_front_bb(c, s) & file_bb(s);
+ unsigned lo = unsigned(occ) & unsigned(Masks[s]);
+ unsigned hi = unsigned(occ >> 32) & unsigned(Masks[s] >> 32);
+ return (lo * unsigned(Magics[s]) ^ hi * unsigned(Magics[s] >> 32)) >> Shifts[s];
}
-
-/// squares_behind is similar to squares_in_front, but returns the squares
-/// behind the square instead of in front of the square.
-
-inline Bitboard squares_behind(Color c, Square s) {
- return in_front_bb(opposite_color(c), s) & file_bb(s);
+template<PieceType Pt>
+inline Bitboard attacks_bb(Square s, Bitboard occ) {
+ return (Pt == ROOK ? RAttacks : BAttacks)[s][magic_index<Pt>(s, occ)];
}
-/// passed_pawn_mask takes a color and a square as input, and returns a
-/// bitboard mask which can be used to test if a pawn of the given color on
-/// the given square is a passed pawn.
-
-inline Bitboard passed_pawn_mask(Color c, Square s) {
- return PassedPawnMask[c][s];
-}
+/// lsb()/msb() finds the least/most significant bit in a nonzero bitboard.
+/// pop_lsb() finds and clears the least significant bit in a nonzero bitboard.
+#if defined(USE_BSFQ)
-/// outpost_mask takes a color and a square as input, and returns a bitboard
-/// mask which can be used to test whether a piece on the square can possibly
-/// be driven away by an enemy pawn.
+# if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
-inline Bitboard outpost_mask(Color c, Square s) {
- return OutpostMask[c][s];
+FORCE_INLINE Square lsb(Bitboard b) {
+ unsigned long index;
+ _BitScanForward64(&index, b);
+ return (Square) index;
}
-
-/// isolated_pawn_mask takes a square as input, and returns a bitboard mask
-/// which can be used to test whether a pawn on the given square is isolated.
-
-inline Bitboard isolated_pawn_mask(Square s) {
- return neighboring_files_bb(s);
+FORCE_INLINE Square msb(Bitboard b) {
+ unsigned long index;
+ _BitScanReverse64(&index, b);
+ return (Square) index;
}
+# elif defined(__arm__)
-/// count_1s() counts the number of nonzero bits in a bitboard.
-
-#if defined(BITCOUNT_LOOP)
-
-inline int count_1s(Bitboard b) {
- int r;
- for(r = 0; b; r++, b &= b - 1);
- return r;
+FORCE_INLINE int lsb32(uint32_t v) {
+ __asm__("rbit %0, %1" : "=r"(v) : "r"(v));
+ return __builtin_clz(v);
}
-inline int count_1s_max_15(Bitboard b) {
- return count_1s(b);
+FORCE_INLINE Square msb(Bitboard b) {
+ return (Square) (63 - __builtin_clzll(b));
}
-#elif defined(BITCOUNT_SWAR_32)
-
-inline int count_1s(Bitboard b) {
- unsigned w = unsigned(b >> 32), v = unsigned(b);
- v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
- w -= (w >> 1) & 0x55555555;
- v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
- w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
- v = ((v >> 4) + v) & 0x0F0F0F0F; // 0-8 in 8 bits
- v += (((w >> 4) + w) & 0x0F0F0F0F); // 0-16 in 8 bits
- v *= 0x01010101; // mul is fast on amd procs
- return int(v >> 24);
+FORCE_INLINE Square lsb(Bitboard b) {
+ return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32)));
}
-inline int count_1s_max_15(Bitboard b) {
- unsigned w = unsigned(b >> 32), v = unsigned(b);
- v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
- w -= (w >> 1) & 0x55555555;
- v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
- w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
- v += w; // 0-8 in 4 bits
- v *= 0x11111111;
- return int(v >> 28);
-}
-
-#elif defined(BITCOUNT_SWAR_64)
+# else
-inline int count_1s(Bitboard b) {
- b -= ((b>>1) & 0x5555555555555555ULL);
- b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
- b = ((b>>4) + b) & 0x0F0F0F0F0F0F0F0FULL;
- b *= 0x0101010101010101ULL;
- return int(b >> 56);
+FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen
+ Bitboard index;
+ __asm__("bsfq %1, %0": "=r"(index): "rm"(b) );
+ return (Square) index;
}
-inline int count_1s_max_15(Bitboard b) {
- b -= (b>>1) & 0x5555555555555555ULL;
- b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
- b *= 0x1111111111111111ULL;
- return int(b >> 60);
+FORCE_INLINE Square msb(Bitboard b) {
+ Bitboard index;
+ __asm__("bsrq %1, %0": "=r"(index): "rm"(b) );
+ return (Square) index;
}
-#endif // BITCOUNT
+# endif
+FORCE_INLINE Square pop_lsb(Bitboard* b) {
+ const Square s = lsb(*b);
+ *b &= ~(1ULL << s);
+ return s;
+}
-////
-//// Prototypes
-////
+#else // if !defined(USE_BSFQ)
-extern void print_bitboard(Bitboard b);
-extern void init_bitboards();
-extern Square first_1(Bitboard b);
-extern Square pop_1st_bit(Bitboard *b);
+extern Square msb(Bitboard b);
+extern Square lsb(Bitboard b);
+extern Square pop_lsb(Bitboard* b);
+#endif
#endif // !defined(BITBOARD_H_INCLUDED)
projects / stockfish / blobdiff