/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2014 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)
+#ifndef BITBOARD_H_INCLUDED
#define BITBOARD_H_INCLUDED
+#include <string>
+
#include "types.h"
-const Bitboard EmptyBoardBB = 0;
+namespace Bitboards {
+
+void init();
+const std::string pretty(Bitboard b);
+
+}
+
+namespace Bitbases {
+
+void init_kpk();
+bool probe_kpk(Square wksq, Square wpsq, Square bksq, Color us);
+
+}
const Bitboard FileABB = 0x0101010101010101ULL;
const Bitboard FileBBB = FileABB << 1;
const Bitboard Rank7BB = Rank1BB << (8 * 6);
const Bitboard Rank8BB = Rank1BB << (8 * 7);
-extern Bitboard SquaresByColorBB[2];
-extern Bitboard FileBB[8];
-extern Bitboard NeighboringFilesBB[8];
-extern Bitboard ThisAndNeighboringFilesBB[8];
-extern Bitboard RankBB[8];
-extern Bitboard InFrontBB[2][8];
-
-extern Bitboard SetMaskBB[65];
-extern Bitboard ClearMaskBB[65];
-
-extern Bitboard NonSlidingAttacksBB[16][64];
-extern Bitboard BetweenBB[64][64];
-
-extern Bitboard SquaresInFrontMask[2][64];
-extern Bitboard PassedPawnMask[2][64];
-extern Bitboard AttackSpanMask[2][64];
-
-extern const uint64_t RMult[64];
-extern const int RShift[64];
-extern Bitboard RMask[64];
-extern int RAttackIndex[64];
-extern Bitboard RAttacks[0x19000];
+CACHE_LINE_ALIGNMENT
+
+extern Bitboard RMasks[SQUARE_NB];
+extern Bitboard RMagics[SQUARE_NB];
+extern Bitboard* RAttacks[SQUARE_NB];
+extern unsigned RShifts[SQUARE_NB];
+
+extern Bitboard BMasks[SQUARE_NB];
+extern Bitboard BMagics[SQUARE_NB];
+extern Bitboard* BAttacks[SQUARE_NB];
+extern unsigned BShifts[SQUARE_NB];
+
+extern Bitboard SquareBB[SQUARE_NB];
+extern Bitboard FileBB[FILE_NB];
+extern Bitboard RankBB[RANK_NB];
+extern Bitboard AdjacentFilesBB[FILE_NB];
+extern Bitboard InFrontBB[COLOR_NB][RANK_NB];
+extern Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
+extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
+extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
+extern Bitboard DistanceRingsBB[SQUARE_NB][8];
+extern Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
+extern Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
+extern Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
+extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
+
+extern int SquareDistance[SQUARE_NB][SQUARE_NB];
+
+const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;
+
+/// 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];
+}
-extern const uint64_t BMult[64];
-extern const int BShift[64];
-extern Bitboard BMask[64];
-extern int BAttackIndex[64];
-extern Bitboard BAttacks[0x1480];
+inline Bitboard& operator|=(Bitboard& b, Square s) {
+ return b |= SquareBB[s];
+}
-extern Bitboard BishopPseudoAttacks[64];
-extern Bitboard RookPseudoAttacks[64];
-extern Bitboard QueenPseudoAttacks[64];
+inline Bitboard& operator^=(Bitboard& b, Square s) {
+ return b ^= SquareBB[s];
+}
-extern uint8_t BitCount8Bit[256];
+inline Bitboard operator|(Bitboard b, Square s) {
+ return b | SquareBB[s];
+}
+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 bool more_than_one(Bitboard b) {
+ return b & (b - 1);
+}
-inline Bitboard bit_is_set(Bitboard b, Square s) {
- return b & SetMaskBB[s];
+inline int square_distance(Square s1, Square s2) {
+ return SquareDistance[s1][s2];
}
-inline void set_bit(Bitboard *b, Square s) {
- *b |= SetMaskBB[s];
+inline int file_distance(Square s1, Square s2) {
+ return abs(file_of(s1) - file_of(s2));
}
-inline void clear_bit(Bitboard *b, Square s) {
- *b &= ClearMaskBB[s];
+inline int rank_distance(Square s1, Square s2) {
+ return abs(rank_of(s1) - rank_of(s2));
}
-/// Functions used to update a bitboard after a move. This is faster
-/// then calling a sequence of clear_bit() + set_bit()
+/// shift_bb() moves bitboard one step along direction Delta. Mainly for pawns.
-inline Bitboard make_move_bb(Square from, Square to) {
- return SetMaskBB[from] | SetMaskBB[to];
-}
+template<Square Delta>
+inline Bitboard shift_bb(Bitboard b) {
-inline void do_move_bb(Bitboard *b, Bitboard move_bb) {
- *b ^= move_bb;
+ return Delta == DELTA_N ? b << 8 : Delta == DELTA_S ? b >> 8
+ : Delta == DELTA_NE ? (b & ~FileHBB) << 9 : Delta == DELTA_SE ? (b & ~FileHBB) >> 7
+ : Delta == DELTA_NW ? (b & ~FileABB) << 7 : Delta == DELTA_SW ? (b & ~FileABB) >> 9
+ : 0;
}
}
inline Bitboard rank_bb(Square s) {
- return RankBB[square_rank(s)];
+ return RankBB[rank_of(s)];
}
inline Bitboard file_bb(File f) {
}
inline Bitboard file_bb(Square s) {
- return FileBB[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.
+/// adjacent_files_bb() takes a file as input and returns a bitboard representing
+/// all squares on the adjacent files.
-inline Bitboard neighboring_files_bb(File f) {
- return NeighboringFilesBB[f];
-}
-
-inline Bitboard neighboring_files_bb(Square s) {
- return NeighboringFilesBB[square_file(s)];
+inline Bitboard adjacent_files_bb(File f) {
+ return AdjacentFilesBB[f];
}
-/// 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.
+/// in_front_bb() takes a color and a rank as input, and returns a bitboard
+/// representing all the squares on all ranks in front of the rank, from the
+/// given color's point of view. For instance, in_front_bb(BLACK, RANK_3) will
+/// give all squares on ranks 1 and 2.
-inline Bitboard this_and_neighboring_files_bb(File f) {
- return ThisAndNeighboringFilesBB[f];
+inline Bitboard in_front_bb(Color c, Rank r) {
+ return InFrontBB[c][r];
}
-inline Bitboard this_and_neighboring_files_bb(Square s) {
- return ThisAndNeighboringFilesBB[square_file(s)];
+
+/// 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 rank, file or diagonal,
+/// 0 is returned.
+
+inline Bitboard between_bb(Square s1, Square s2) {
+ return BetweenBB[s1][s2];
}
-/// in_front_bb() takes a color and a rank or square as input, and returns a
-/// bitboard representing all the squares on all ranks in front of the rank
-/// (or square), from the given color's point of view. For instance,
-/// in_front_bb(WHITE, RANK_5) will give all squares on ranks 6, 7 and 8, while
-/// in_front_bb(BLACK, SQ_D3) will give all squares on ranks 1 and 2.
+/// 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 in_front_bb(Color c, Rank r) {
- return InFrontBB[c][r];
+inline Bitboard forward_bb(Color c, Square s) {
+ return ForwardBB[c][s];
}
-inline Bitboard in_front_bb(Color c, Square s) {
- return InFrontBB[c][square_rank(s)];
-}
+/// pawn_attack_span() 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:
+/// PawnAttackSpan[c][s] = in_front_bb(c, s) & adjacent_files_bb(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.
+inline Bitboard pawn_attack_span(Color c, Square s) {
+ return PawnAttackSpan[c][s];
+}
-#if defined(IS_64BIT)
-inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
- Bitboard b = blockers & RMask[s];
- return RAttacks[RAttackIndex[s] + ((b * RMult[s]) >> RShift[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] = pawn_attack_span(c, s) | forward_bb(c, s)
-inline Bitboard bishop_attacks_bb(Square s, Bitboard blockers) {
- Bitboard b = blockers & BMask[s];
- return BAttacks[BAttackIndex[s] + ((b * BMult[s]) >> BShift[s])];
+inline Bitboard passed_pawn_mask(Color c, Square s) {
+ return PassedPawnMask[c][s];
}
-#else // if !defined(IS_64BIT)
-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])];
-}
+/// squares_of_color() returns a bitboard representing all squares with the same
+/// color of the given square.
-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 Bitboard squares_of_color(Square s) {
+ return DarkSquares & s ? DarkSquares : ~DarkSquares;
}
-#endif
-inline Bitboard queen_attacks_bb(Square s, Bitboard blockers) {
- return rook_attacks_bb(s, blockers) | bishop_attacks_bb(s, blockers);
+/// 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;
}
-/// 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 (HasPext)
+ return unsigned(_pext_u64(occ, Masks[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. Definition of the table is:
-/// SquaresInFrontOf[c][s] = in_front_bb(c, s) & file_bb(s)
+ if (Is64Bit)
+ return unsigned(((occ & Masks[s]) * Magics[s]) >> Shifts[s]);
-inline Bitboard squares_in_front_of(Color c, Square s) {
- return SquaresInFrontMask[c][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];
}
+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. Definition of the table is:
-/// PassedPawnMask[c][s] = in_front_bb(c, s) & this_and_neighboring_files_bb(s)
+inline Bitboard attacks_bb(Piece pc, Square s, Bitboard occ) {
-inline Bitboard passed_pawn_mask(Color c, Square s) {
- return PassedPawnMask[c][s];
+ switch (type_of(pc))
+ {
+ case BISHOP: return attacks_bb<BISHOP>(s, occ);
+ case ROOK : return attacks_bb<ROOK>(s, occ);
+ case QUEEN : return attacks_bb<BISHOP>(s, occ) | attacks_bb<ROOK>(s, occ);
+ default : return StepAttacksBB[pc][s];
+ }
}
+/// lsb()/msb() finds the least/most significant bit in a non-zero bitboard.
+/// pop_lsb() finds and clears the least significant bit in a non-zero bitboard.
-/// 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) & neighboring_files_bb(s);
+#ifdef USE_BSFQ
+
+# if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
-inline Bitboard attack_span_mask(Color c, Square s) {
- return AttackSpanMask[c][s];
+FORCE_INLINE Square lsb(Bitboard b) {
+ unsigned long idx;
+ _BitScanForward64(&idx, b);
+ return (Square) idx;
}
+FORCE_INLINE Square msb(Bitboard b) {
+ unsigned long idx;
+ _BitScanReverse64(&idx, b);
+ return (Square) idx;
+}
-/// squares_aligned returns true if the squares s1, s2 and s3 are aligned
-/// either on a straight or on a diagonal line.
+# elif defined(__arm__)
-inline bool squares_aligned(Square s1, Square s2, Square s3) {
- return (BetweenBB[s1][s2] | BetweenBB[s1][s3] | BetweenBB[s2][s3])
- & ((1ULL << s1) | (1ULL << s2) | (1ULL << s3));
+FORCE_INLINE int lsb32(uint32_t v) {
+ __asm__("rbit %0, %1" : "=r"(v) : "r"(v));
+ return __builtin_clz(v);
}
+FORCE_INLINE Square msb(Bitboard b) {
+ return (Square) (63 - __builtin_clzll(b));
+}
-/// first_1() finds the least significant nonzero bit in a nonzero bitboard.
-/// pop_1st_bit() finds and clears the least significant nonzero bit in a
-/// nonzero bitboard.
+FORCE_INLINE Square lsb(Bitboard b) {
+ return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32)));
+}
-#if defined(USE_BSFQ) // Assembly code by Heinz van Saanen
+# else
-inline Square first_1(Bitboard b) {
- Bitboard dummy;
- __asm__("bsfq %1, %0": "=r"(dummy): "rm"(b) );
- return (Square)(dummy);
+FORCE_INLINE Square lsb(Bitboard b) { // Assembly code by Heinz van Saanen
+ Bitboard idx;
+ __asm__("bsfq %1, %0": "=r"(idx): "rm"(b) );
+ return (Square) idx;
}
-inline Square pop_1st_bit(Bitboard* b) {
- const Square s = first_1(*b);
- *b &= ~(1ULL<<s);
+FORCE_INLINE Square msb(Bitboard b) {
+ Bitboard idx;
+ __asm__("bsrq %1, %0": "=r"(idx): "rm"(b) );
+ return (Square) idx;
+}
+
+# endif
+
+FORCE_INLINE Square pop_lsb(Bitboard* b) {
+ const Square s = lsb(*b);
+ *b &= *b - 1;
return s;
}
-#else // if !defined(USE_BSFQ)
+#else // if defined(USE_BSFQ)
-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
+/// frontmost_sq() and backmost_sq() find the square corresponding to the
+/// most/least advanced bit relative to the given color.
-extern void print_bitboard(Bitboard b);
-extern void init_bitboards();
+inline Square frontmost_sq(Color c, Bitboard b) { return c == WHITE ? msb(b) : lsb(b); }
+inline Square backmost_sq(Color c, Bitboard b) { return c == WHITE ? lsb(b) : msb(b); }
-#endif // !defined(BITBOARD_H_INCLUDED)
+#endif // #ifndef BITBOARD_H_INCLUDED
projects / stockfish / blobdiff