attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN];
attackedBy2[Us] = attackedBy[Us][KING] & attackedBy[Us][PAWN];
- kingRing[Us] = kingAttackersCount[Them] = 0;
+ // Init our king safety tables
+ kingRing[Us] = attackedBy[Us][KING];
+ if (relative_rank(Us, pos.square<KING>(Us)) == RANK_1)
+ kingRing[Us] |= shift<Up>(kingRing[Us]);
- // Init our king safety tables only if we are going to use them
- if (pos.non_pawn_material(Them) >= RookValueMg + KnightValueMg)
- {
- kingRing[Us] = attackedBy[Us][KING];
- if (relative_rank(Us, pos.square<KING>(Us)) == RANK_1)
- kingRing[Us] |= shift<Up>(kingRing[Us]);
-
- if (file_of(pos.square<KING>(Us)) == FILE_H)
- kingRing[Us] |= shift<WEST>(kingRing[Us]);
+ if (file_of(pos.square<KING>(Us)) == FILE_H)
+ kingRing[Us] |= shift<WEST>(kingRing[Us]);
- else if (file_of(pos.square<KING>(Us)) == FILE_A)
- kingRing[Us] |= shift<EAST>(kingRing[Us]);
+ else if (file_of(pos.square<KING>(Us)) == FILE_A)
+ kingRing[Us] |= shift<EAST>(kingRing[Us]);
- kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
- kingRing[Us] &= ~double_pawn_attacks_bb<Us>(pos.pieces(Us, PAWN));
- kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
- }
+ kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
+ kingRing[Us] &= ~double_pawn_attacks_bb<Us>(pos.pieces(Us, PAWN));
+ kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
}
int tropism = popcount(b1) + popcount(b2);
// Main king safety evaluation
- if (kingAttackersCount[Them] > 1 - pos.count<QUEEN>(Them))
- {
- int kingDanger = 0;
- unsafeChecks = 0;
+ int kingDanger = 0;
+ unsafeChecks = 0;
- // Attacked squares defended at most once by our queen or king
- weak = attackedBy[Them][ALL_PIECES]
- & ~attackedBy2[Us]
- & (~attackedBy[Us][ALL_PIECES] | attackedBy[Us][KING] | attackedBy[Us][QUEEN]);
+ // Attacked squares defended at most once by our queen or king
+ weak = attackedBy[Them][ALL_PIECES]
+ & ~attackedBy2[Us]
+ & (~attackedBy[Us][ALL_PIECES] | attackedBy[Us][KING] | attackedBy[Us][QUEEN]);
- // Analyse the safe enemy's checks which are possible on next move
- safe = ~pos.pieces(Them);
- safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]);
+ // Analyse the safe enemy's checks which are possible on next move
+ safe = ~pos.pieces(Them);
+ safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]);
- b1 = attacks_bb<ROOK >(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
- b2 = attacks_bb<BISHOP>(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
+ b1 = attacks_bb<ROOK >(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
+ b2 = attacks_bb<BISHOP>(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
- // Enemy queen safe checks
- if ((b1 | b2) & attackedBy[Them][QUEEN] & safe & ~attackedBy[Us][QUEEN])
- kingDanger += QueenSafeCheck;
+ // Enemy queen safe checks
+ if ((b1 | b2) & attackedBy[Them][QUEEN] & safe & ~attackedBy[Us][QUEEN])
+ kingDanger += QueenSafeCheck;
- b1 &= attackedBy[Them][ROOK];
- b2 &= attackedBy[Them][BISHOP];
+ b1 &= attackedBy[Them][ROOK];
+ b2 &= attackedBy[Them][BISHOP];
- // Enemy rooks checks
- if (b1 & safe)
- kingDanger += RookSafeCheck;
- else
- unsafeChecks |= b1;
+ // Enemy rooks checks
+ if (b1 & safe)
+ kingDanger += RookSafeCheck;
+ else
+ unsafeChecks |= b1;
- // Enemy bishops checks
- if (b2 & safe)
- kingDanger += BishopSafeCheck;
- else
- unsafeChecks |= b2;
+ // Enemy bishops checks
+ if (b2 & safe)
+ kingDanger += BishopSafeCheck;
+ else
+ unsafeChecks |= b2;
- // Enemy knights checks
- b = pos.attacks_from<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
- if (b & safe)
- kingDanger += KnightSafeCheck;
- else
- unsafeChecks |= b;
-
- // Unsafe or occupied checking squares will also be considered, as long as
- // the square is in the attacker's mobility area.
- unsafeChecks &= mobilityArea[Them];
-
- kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
- + 69 * kingAttacksCount[Them]
- + 185 * popcount(kingRing[Us] & weak)
- + 150 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
- + tropism * tropism / 4
- - 873 * !pos.count<QUEEN>(Them)
- - 6 * mg_value(score) / 8
- + mg_value(mobility[Them] - mobility[Us])
- - 30;
-
- // Transform the kingDanger units into a Score, and subtract it from the evaluation
- if (kingDanger > 0)
- score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
- }
+ // Enemy knights checks
+ b = pos.attacks_from<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
+ if (b & safe)
+ kingDanger += KnightSafeCheck;
+ else
+ unsafeChecks |= b;
+
+ // Unsafe or occupied checking squares will also be considered, as long as
+ // the square is in the attacker's mobility area.
+ unsafeChecks &= mobilityArea[Them];
+
+ kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
+ + 69 * kingAttacksCount[Them]
+ + 185 * popcount(kingRing[Us] & weak)
+ + 150 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
+ + tropism * tropism / 4
+ - 873 * !pos.count<QUEEN>(Them)
+ - 6 * mg_value(score) / 8
+ + mg_value(mobility[Them] - mobility[Us])
+ - 30;
+
+ // Transform the kingDanger units into a Score, and subtract it from the evaluation
+ if (kingDanger > 0)
+ score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
// Penalty when our king is on a pawnless flank
if (!(pos.pieces(PAWN) & kingFlank))
projects / stockfish / blobdiff