/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2013 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 "types.h"
-CACHE_LINE_ALIGNMENT
+namespace Bitboards {
+
+void init();
+void print(Bitboard b);
+
+}
+
+namespace Bitbases {
+
+void init_kpk();
+bool probe_kpk(Square wksq, Square wpsq, Square bksq, Color us);
-extern Bitboard RMasks[64];
-extern Bitboard RMagics[64];
-extern Bitboard* RAttacks[64];
-extern unsigned RShifts[64];
-
-extern Bitboard BMasks[64];
-extern Bitboard BMagics[64];
-extern Bitboard* BAttacks[64];
-extern unsigned BShifts[64];
-
-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 SquaresInFrontMask[2][64];
-extern Bitboard PassedPawnMask[2][64];
-extern Bitboard AttackSpanMask[2][64];
-extern Bitboard PseudoAttacks[6][64];
+}
+
+const Bitboard FileABB = 0x0101010101010101ULL;
+const Bitboard FileBBB = FileABB << 1;
+const Bitboard FileCBB = FileABB << 2;
+const Bitboard FileDBB = FileABB << 3;
+const Bitboard FileEBB = FileABB << 4;
+const Bitboard FileFBB = FileABB << 5;
+const Bitboard FileGBB = FileABB << 6;
+const Bitboard FileHBB = FileABB << 7;
+
+const Bitboard Rank1BB = 0xFF;
+const Bitboard Rank2BB = Rank1BB << (8 * 1);
+const Bitboard Rank3BB = Rank1BB << (8 * 2);
+const Bitboard Rank4BB = Rank1BB << (8 * 3);
+const Bitboard Rank5BB = Rank1BB << (8 * 4);
+const Bitboard Rank6BB = Rank1BB << (8 * 5);
+const Bitboard Rank7BB = Rank1BB << (8 * 6);
+const Bitboard Rank8BB = Rank1BB << (8 * 7);
+
+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 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 BlackSquares = 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.
return b ^ SquareBB[s];
}
+inline bool more_than_one(Bitboard b) {
+ return b & (b - 1);
+}
+
+inline int square_distance(Square s1, Square s2) {
+ return SquareDistance[s1][s2];
+}
+
+inline int file_distance(Square s1, Square s2) {
+ return abs(file_of(s1) - file_of(s2));
+}
+
+inline int rank_distance(Square s1, Square s2) {
+ return abs(rank_of(s1) - rank_of(s2));
+}
+
+
+/// shift_bb() moves bitboard one step along direction Delta. Mainly for pawns.
+
+template<Square Delta>
+inline Bitboard shift_bb(Bitboard b) {
+
+ 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;
+}
+
/// 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.
}
-/// adjacent_files_bb takes a file as input and returns a bitboard representing
+/// adjacent_files_bb() takes a file as input and returns a bitboard representing
/// all squares on the adjacent files.
inline Bitboard adjacent_files_bb(File f) {
}
-/// 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 this_and_adjacent_files_bb(File f) {
- return ThisAndAdjacentFilesBB[f];
-}
-
-
-/// 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.
+/// 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 in_front_bb(Color c, Rank r) {
return InFrontBB[c][r];
}
-inline Bitboard in_front_bb(Color c, Square s) {
- return InFrontBB[c][rank_of(s)];
-}
-
-
-/// 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) {
-
- 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]);
-
- 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];
-}
+/// 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.
-template<PieceType Pt>
-inline Bitboard attacks_bb(Square s, Bitboard occ) {
- Bitboard** const Attacks = Pt == ROOK ? RAttacks : BAttacks;
- return Attacks[s][magic_index<Pt>(s, occ)];
+inline Bitboard between_bb(Square s1, Square s2) {
+ return BetweenBB[s1][s2];
}
-/// 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.
+/// 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 squares_between(Square s1, Square s2) {
- return BetweenBB[s1][s2];
+inline Bitboard forward_bb(Color c, Square s) {
+ return ForwardBB[c][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)
+/// 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);
-inline Bitboard squares_in_front_of(Color c, Square s) {
- return SquaresInFrontMask[c][s];
+inline Bitboard pawn_attack_span(Color c, Square s) {
+ return PawnAttackSpan[c][s];
}
-/// passed_pawn_mask takes a color and a square as input, and returns a
+/// 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)
+/// PassedPawnMask[c][s] = pawn_attack_span(c, s) | forward_bb(c, s)
inline Bitboard passed_pawn_mask(Color c, Square s) {
return PassedPawnMask[c][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);
-
-inline Bitboard attack_span_mask(Color c, Square s) {
- return AttackSpanMask[c][s];
-}
-
-
-/// squares_aligned returns true if the squares s1, s2 and s3 are aligned
+/// squares_aligned() returns true if the squares s1, s2 and s3 are aligned
/// either on a straight or on a diagonal line.
inline bool squares_aligned(Square s1, Square s2, Square s3) {
/// the same color of the given square.
inline Bitboard same_color_squares(Square s) {
- return Bitboard(0xAA55AA55AA55AA55ULL) & s ? 0xAA55AA55AA55AA55ULL
- : ~0xAA55AA55AA55AA55ULL;
+ return BlackSquares & s ? BlackSquares : ~BlackSquares;
}
-/// single_bit() returns true if in the 'b' bitboard is set a single bit (or if
-/// b == 0).
+/// 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 bool single_bit(Bitboard b) {
- return !(b & (b - 1));
+ 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]);
+
+ 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)];
}
-/// 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.
+/// 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)
+#ifdef USE_BSFQ
-#if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
+# if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
-FORCE_INLINE Square first_1(Bitboard b) {
+FORCE_INLINE Square lsb(Bitboard b) {
unsigned long index;
_BitScanForward64(&index, b);
return (Square) index;
}
-FORCE_INLINE Square last_1(Bitboard b) {
+FORCE_INLINE Square msb(Bitboard b) {
unsigned long index;
_BitScanReverse64(&index, b);
return (Square) index;
}
-#else
-FORCE_INLINE Square first_1(Bitboard b) { // Assembly code by Heinz van Saanen
- Bitboard dummy;
- __asm__("bsfq %1, %0": "=r"(dummy): "rm"(b) );
- return (Square) dummy;
+# elif defined(__arm__)
+
+FORCE_INLINE int lsb32(uint32_t v) {
+ __asm__("rbit %0, %1" : "=r"(v) : "r"(v));
+ return __builtin_clz(v);
}
-FORCE_INLINE Square last_1(Bitboard b) {
- Bitboard dummy;
- __asm__("bsrq %1, %0": "=r"(dummy): "rm"(b) );
- return (Square) dummy;
+FORCE_INLINE Square msb(Bitboard b) {
+ return (Square) (63 - __builtin_clzll(b));
}
-#endif
-FORCE_INLINE Square pop_1st_bit(Bitboard* b) {
- const Square s = first_1(*b);
- *b &= ~(1ULL<<s);
+FORCE_INLINE Square lsb(Bitboard b) {
+ return (Square) (uint32_t(b) ? lsb32(uint32_t(b)) : 32 + lsb32(uint32_t(b >> 32)));
+}
+
+# else
+
+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;
+}
+
+FORCE_INLINE Square msb(Bitboard b) {
+ Bitboard index;
+ __asm__("bsrq %1, %0": "=r"(index): "rm"(b) );
+ return (Square) index;
+}
+
+# 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 last_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
-extern void print_bitboard(Bitboard b);
-extern void bitboards_init();
-
-#endif // !defined(BITBOARD_H_INCLUDED)
+#endif // #ifndef BITBOARD_H_INCLUDED
projects / stockfish / blobdiff