void Bitboards::init() {
for (unsigned i = 0; i < (1 << 16); ++i)
- PopCnt16[i] = std::bitset<16>(i).count();
+ PopCnt16[i] = uint8_t(std::bitset<16>(i).count());
for (Square s = SQ_A1; s <= SQ_H8; ++s)
SquareBB[s] = (1ULL << s);
for (Square s2 = SQ_A1; s2 <= SQ_H8; ++s2)
SquareDistance[s1][s2] = std::max(distance<File>(s1, s2), distance<Rank>(s1, s2));
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- {
- PawnAttacks[WHITE][s] = pawn_attacks_bb<WHITE>(square_bb(s));
- PawnAttacks[BLACK][s] = pawn_attacks_bb<BLACK>(square_bb(s));
- }
-
- // Helper returning the target bitboard of a step from a square
- auto landing_square_bb = [&](Square s, int step)
- {
- Square to = Square(s + step);
- return is_ok(to) && distance(s, to) <= 2 ? square_bb(to) : Bitboard(0);
- };
-
- for (Square s = SQ_A1; s <= SQ_H8; ++s)
- {
- for (int step : {-9, -8, -7, -1, 1, 7, 8, 9} )
- PseudoAttacks[KING][s] |= landing_square_bb(s, step);
-
- for (int step : {-17, -15, -10, -6, 6, 10, 15, 17} )
- PseudoAttacks[KNIGHT][s] |= landing_square_bb(s, step);
- }
-
Direction RookDirections[] = { NORTH, EAST, SOUTH, WEST };
Direction BishopDirections[] = { NORTH_EAST, SOUTH_EAST, SOUTH_WEST, NORTH_WEST };
for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
{
+ PawnAttacks[WHITE][s1] = pawn_attacks_bb<WHITE>(square_bb(s1));
+ PawnAttacks[BLACK][s1] = pawn_attacks_bb<BLACK>(square_bb(s1));
+
+ for (int step : {-9, -8, -7, -1, 1, 7, 8, 9} )
+ PseudoAttacks[KING][s1] |= safe_destination(s1, step);
+
+ for (int step : {-17, -15, -10, -6, 6, 10, 15, 17} )
+ PseudoAttacks[KNIGHT][s1] |= safe_destination(s1, step);
+
PseudoAttacks[QUEEN][s1] = PseudoAttacks[BISHOP][s1] = attacks_bb<BISHOP>(s1, 0);
PseudoAttacks[QUEEN][s1] |= PseudoAttacks[ ROOK][s1] = attacks_bb< ROOK>(s1, 0);
Bitboard sliding_attack(Direction directions[], Square sq, Bitboard occupied) {
- Bitboard attack = 0;
+ Bitboard attacks = 0;
for (int i = 0; i < 4; ++i)
- for (Square s = sq + directions[i];
- is_ok(s) && distance(s, s - directions[i]) == 1;
- s += directions[i])
- {
- attack |= s;
-
- if (occupied & s)
- break;
- }
+ {
+ Square s = sq;
+ while(safe_destination(s, directions[i]) && !(occupied & s))
+ attacks |= (s += directions[i]);
+ }
- return attack;
+ return attacks;
}