/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2009 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
#if !defined(BITBOARD_H_INCLUDED)
#define BITBOARD_H_INCLUDED
-////
-//// Defines
-////
-
-// 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
-
////
//// 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;
-const Bitboard SquaresByColorBB[2] = { BlackSquaresBB, WhiteSquaresBB };
+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 FileBB[8] = {
- FileABB, FileBBB, FileCBB, FileDBB, FileEBB, FileFBB, FileGBB, FileHBB
-};
-
-const Bitboard NeighboringFilesBB[8] = {
- FileBBB, FileABB|FileCBB, FileBBB|FileDBB, FileCBB|FileEBB,
- FileDBB|FileFBB, FileEBB|FileGBB, FileFBB|FileHBB, FileGBB
-};
-
-const Bitboard ThisAndNeighboringFilesBB[8] = {
- FileABB|FileBBB, FileABB|FileBBB|FileCBB,
- FileBBB|FileCBB|FileDBB, FileCBB|FileDBB|FileEBB,
- FileDBB|FileEBB|FileFBB, FileEBB|FileFBB|FileGBB,
- FileFBB|FileGBB|FileHBB, FileGBB|FileHBB
-};
-
-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;
-
-const Bitboard RankBB[8] = {
- Rank1BB, Rank2BB, Rank3BB, Rank4BB, Rank5BB, Rank6BB, Rank7BB, Rank8BB
-};
-
-const Bitboard RelativeRankBB[2][8] = {
- { Rank1BB, Rank2BB, Rank3BB, Rank4BB, Rank5BB, Rank6BB, Rank7BB, Rank8BB },
- { Rank8BB, Rank7BB, Rank6BB, Rank5BB, Rank4BB, Rank3BB, Rank2BB, Rank1BB }
-};
-
-const Bitboard InFrontBB[2][8] = {
- { Rank2BB | Rank3BB | Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
- Rank3BB | Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
- Rank4BB | Rank5BB | Rank6BB | Rank7BB | Rank8BB,
- Rank5BB | Rank6BB | Rank7BB | Rank8BB,
- Rank6BB | Rank7BB | Rank8BB,
- Rank7BB | Rank8BB,
- Rank8BB,
- EmptyBoardBB
- },
- { EmptyBoardBB,
- Rank1BB,
- Rank2BB | Rank1BB,
- Rank3BB | Rank2BB | Rank1BB,
- Rank4BB | Rank3BB | Rank2BB | Rank1BB,
- Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB,
- Rank6BB | Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB,
- Rank7BB | Rank6BB | Rank5BB | Rank4BB | Rank3BB | Rank2BB | Rank1BB
- }
-};
-
-const int BitTable[64] = {
- 63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2,
- 51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52,
- 26, 60, 6, 23, 44, 46, 27, 56, 16, 7, 39, 48, 24, 59, 14, 12, 55, 38, 28,
- 58, 20, 37, 17, 36, 8
-};
+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];
+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 RayBB[64][8];
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];
extern const uint64_t RMult[64];
extern const int RShift[64];
extern Bitboard RookPseudoAttacks[64];
extern Bitboard QueenPseudoAttacks[64];
+extern uint8_t BitCount8Bit[256];
+
////
//// Inline functions
*b ^= move_bb;
}
-/// 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 neighboring_files_bb(Square s) {
- return neighboring_files_bb(square_file(s));
+ return NeighboringFilesBB[square_file(s)];
}
}
inline Bitboard this_and_neighboring_files_bb(Square s) {
- return this_and_neighboring_files_bb(square_file(s));
+ return ThisAndNeighboringFilesBB[square_file(s)];
}
}
inline Bitboard in_front_bb(Color c, Square s) {
- return in_front_bb(c, square_rank(s));
+ return InFrontBB[c][square_rank(s)];
}
}
inline Bitboard behind_bb(Color c, Square s) {
- return in_front_bb(opposite_color(c), square_rank(s));
+ return InFrontBB[opposite_color(c)][square_rank(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.
+/// 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);
+ return SquaresInFrontMask[c][s];
}
/// 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[opposite_color(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.
-
-inline Bitboard outpost_mask(Color c, Square s) {
- return OutpostMask[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.
+/// 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 isolated_pawn_mask(Square s) {
- return neighboring_files_bb(s);
+inline Bitboard attack_span_mask(Color c, Square s) {
+ return AttackSpanMask[c][s];
}
/// 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.
-#if defined(IS_64BIT)
+#if defined(USE_BSFQ) // Assembly code by Heinz van Saanen
inline Square first_1(Bitboard b) {
- return Square(BitTable[((b & -b) * 0x218a392cd3d5dbfULL) >> 58]);
+ Bitboard dummy;
+ __asm__("bsfq %1, %0": "=r"(dummy): "rm"(b) );
+ return (Square)(dummy);
}
-#else
-
-inline Square first_1(Bitboard b) {
- b ^= (b - 1);
- uint32_t fold = int(b) ^ int(b >> 32);
- return Square(BitTable[(fold * 0x783a9b23) >> 26]);
+inline Square pop_1st_bit(Bitboard* b) {
+ const Square s = first_1(*b);
+ *b &= ~(1ULL<<s);
+ return s;
}
+#else // if !defined(USE_BSFQ)
+
+extern Square first_1(Bitboard b);
+extern Square pop_1st_bit(Bitboard* b);
+
#endif
extern void print_bitboard(Bitboard b);
extern void init_bitboards();
-extern Square pop_1st_bit(Bitboard *b);
#endif // !defined(BITBOARD_H_INCLUDED)
projects / stockfish / blobdiff