/*
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) 2008-2010 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"
-
-////
-//// Types
-////
-
-typedef uint64_t Bitboard;
-
-
-////
-//// Constants and variables
-////
-
-const Bitboard EmptyBoardBB = 0ULL;
-
-const Bitboard WhiteSquaresBB = 0x55AA55AA55AA55AAULL;
-const Bitboard BlackSquaresBB = 0xAA55AA55AA55AA55ULL;
-
-extern const Bitboard SquaresByColorBB[2];
+const Bitboard EmptyBoardBB = 0;
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;
+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);
+extern const Bitboard SquaresByColorBB[2];
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;
-
extern const Bitboard RankBB[8];
-extern const Bitboard RelativeRankBB[2][8];
extern const Bitboard InFrontBB[2][8];
extern Bitboard SetMaskBB[65];
extern Bitboard ClearMaskBB[65];
-extern Bitboard StepAttackBB[16][64];
-extern Bitboard RayBB[64][8];
+extern Bitboard StepAttacksBB[16][64];
extern Bitboard BetweenBB[64][64];
+extern Bitboard SquaresInFrontMask[2][64];
extern Bitboard PassedPawnMask[2][64];
-extern Bitboard OutpostMask[2][64];
+extern Bitboard AttackSpanMask[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 const uint64_t BMult[64];
extern const int BShift[64];
extern Bitboard RookPseudoAttacks[64];
extern Bitboard QueenPseudoAttacks[64];
+extern uint8_t BitCount8Bit[256];
-////
-//// Inline functions
-////
/// Functions for testing whether a given bit is set in a bitboard, and for
/// setting and clearing bits.
}
-/// 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.
+/// Functions used to update a bitboard after a move. This is faster
+/// then calling a sequence of clear_bit() + set_bit()
+
+inline Bitboard make_move_bb(Square from, Square to) {
+ return SetMaskBB[from] | SetMaskBB[to];
+}
+
+inline void do_move_bb(Bitboard *b, Bitboard move_bb) {
+ *b ^= move_bb;
+}
+
+
+/// 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[square_rank(s)];
}
inline Bitboard file_bb(File f) {
}
inline Bitboard file_bb(Square s) {
- return file_bb(square_file(s));
+ return FileBB[square_file(s)];
}
-/// neighboring_files_bb takes a file or a square as input, and returns a
+/// 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) {
}
inline Bitboard neighboring_files_bb(Square s) {
- return neighboring_files_bb(square_file(s));
+ return NeighboringFilesBB[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.
+/// 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];
}
inline Bitboard this_and_neighboring_files_bb(Square s) {
- return this_and_neighboring_files_bb(square_file(s));
-}
-
-
-/// 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.
-
-inline Bitboard relative_rank_bb(Color c, Rank r) {
- return RelativeRankBB[c][r];
+ return ThisAndNeighboringFilesBB[square_file(s)];
}
}
inline Bitboard in_front_bb(Color c, Square s) {
- return in_front_bb(c, square_rank(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.
-
-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));
-}
-
-
-/// ray_bb() gives a bitboard representing all squares along the ray in a
-/// given direction from a given square.
-
-inline Bitboard ray_bb(Square s, SignedDirection d) {
- return RayBB[s][d];
+ return InFrontBB[c][square_rank(s)];
}
-/// Functions for computing sliding attack bitboards. rook_attacks_bb(),
+/// 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);
-}
+#if defined(IS_64BIT)
inline Bitboard rook_attacks_bb(Square s, Bitboard blockers) {
- return file_attacks_bb(s, blockers) | rank_attacks_bb(s, blockers);
+ Bitboard b = blockers & RMask[s];
+ return RAttacks[RAttackIndex[s] + ((b * RMult[s]) >> RShift[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])];
+inline Bitboard bishop_attacks_bb(Square s, Bitboard blockers) {
+ Bitboard b = blockers & BMask[s];
+ return BAttacks[BAttackIndex[s] + ((b * BMult[s]) >> BShift[s])];
}
-#else
+#else // 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])];
+ return RAttacks[RAttackIndex[s] +
+ (unsigned(int(b) * int(RMult[s]) ^ int(b >> 32) * int(RMult[s] >> 32)) >> RShift[s])];
}
-#endif
-
-#if defined(USE_32BIT_ATTACKS)
-
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])];
-}
-
-#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])];
+ (unsigned(int(b) * int(BMult[s]) ^ int(b >> 32) * int(BMult[s] >> 32)) >> BShift[s])];
}
-#endif // defined(USE_32BIT_ATTACKS)
+#endif
inline Bitboard queen_attacks_bb(Square s, Bitboard blockers) {
return rook_attacks_bb(s, blockers) | bishop_attacks_bb(s, blockers);
/// 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.
+/// 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)
inline Bitboard squares_in_front_of(Color c, Square s) {
- return in_front_bb(c, s) & file_bb(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);
+ return SquaresInFrontMask[c][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.
+/// 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 passed_pawn_mask(Color c, Square s) {
return PassedPawnMask[c][s];
}
-/// 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.
+/// 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);
-inline Bitboard outpost_mask(Color c, Square s) {
- return OutpostMask[c][s];
+inline Bitboard attack_span_mask(Color c, Square s) {
+ return AttackSpanMask[c][s];
}
-/// 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.
+/// squares_aligned returns true if the squares s1, s2 and s3 are aligned
+/// either on a straight or on a diagonal line.
-inline Bitboard isolated_pawn_mask(Square s) {
- return neighboring_files_bb(s);
+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));
}
-/// count_1s() counts the number of nonzero bits in a bitboard.
-
-#if defined(BITCOUNT_LOOP)
+/// 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.
-inline int count_1s(Bitboard b) {
- int r;
- for(r = 0; b; r++, b &= b - 1);
- return r;
-}
-
-inline int count_1s_max_15(Bitboard b) {
- return count_1s(b);
-}
+#if defined(USE_BSFQ) // Assembly code by Heinz van Saanen
-#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);
+inline Square first_1(Bitboard b) {
+ Bitboard dummy;
+ __asm__("bsfq %1, %0": "=r"(dummy): "rm"(b) );
+ return (Square)(dummy);
}
-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);
+inline Square pop_1st_bit(Bitboard* b) {
+ const Square s = first_1(*b);
+ *b &= ~(1ULL<<s);
+ return s;
}
-#elif defined(BITCOUNT_SWAR_64)
+#else // if !defined(USE_BSFQ)
-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);
-}
-
-inline int count_1s_max_15(Bitboard b) {
- b -= (b>>1) & 0x5555555555555555ULL;
- b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
- b *= 0x1111111111111111ULL;
- return int(b >> 60);
-}
-
-#endif // BITCOUNT
+extern Square first_1(Bitboard b);
+extern Square pop_1st_bit(Bitboard* b);
+#endif
-////
-//// Prototypes
-////
extern void print_bitboard(Bitboard b);
extern void init_bitboards();
-extern Square first_1(Bitboard b);
-extern Square pop_1st_bit(Bitboard *b);
-
#endif // !defined(BITBOARD_H_INCLUDED)
projects / stockfish / blobdiff