/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+ Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
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/>.
*/
+#include "bitboard.h"
+
#include <algorithm>
#include <bitset>
+#include <initializer_list>
-#include "bitboard.h"
#include "misc.h"
+namespace Stockfish {
+
uint8_t PopCnt16[1 << 16];
uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
-Bitboard SquareBB[SQUARE_NB];
Bitboard LineBB[SQUARE_NB][SQUARE_NB];
+Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
}
-
-/// safe_destination() returns the bitboard of target square for the given step
-/// from the given square. If the step is off the board, returns empty bitboard.
+// safe_destination() returns the bitboard of target square for the given step
+// from the given square. If the step is off the board, returns empty bitboard.
inline Bitboard safe_destination(Square s, int step) {
Square to = Square(s + step);
}
-/// Bitboards::pretty() returns an ASCII representation of a bitboard suitable
-/// to be printed to standard output. Useful for debugging.
+// Bitboards::pretty() returns an ASCII representation of a bitboard suitable
+// to be printed to standard output. Useful for debugging.
-const std::string Bitboards::pretty(Bitboard b) {
+std::string Bitboards::pretty(Bitboard b) {
std::string s = "+---+---+---+---+---+---+---+---+\n";
}
-/// Bitboards::init() initializes various bitboard tables. It is called at
-/// startup and relies on global objects to be already zero-initialized.
+// Bitboards::init() initializes various bitboard tables. It is called at
+// startup and relies on global objects to be already zero-initialized.
void Bitboards::init() {
for (unsigned i = 0; i < (1 << 16); ++i)
PopCnt16[i] = uint8_t(std::bitset<16>(i).count());
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- SquareBB[s] = (1ULL << s);
-
for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
for (PieceType pt : { BISHOP, ROOK })
for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
+ {
if (PseudoAttacks[pt][s1] & s2)
- LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
+ {
+ LineBB[s1][s2] = (attacks_bb(pt, s1, 0) & attacks_bb(pt, s2, 0)) | s1 | s2;
+ BetweenBB[s1][s2] = (attacks_bb(pt, s1, square_bb(s2)) & attacks_bb(pt, s2, square_bb(s1)));
+ }
+ BetweenBB[s1][s2] |= s2;
+ }
}
}
-
namespace {
Bitboard sliding_attack(PieceType pt, Square sq, Bitboard occupied) {
for (Direction d : (pt == ROOK ? RookDirections : BishopDirections))
{
Square s = sq;
- while(safe_destination(s, d) && !(occupied & s))
+ while (safe_destination(s, d) && !(occupied & s))
attacks |= (s += d);
}
}
}
}
+
+} // namespace Stockfish