// Our rank plus previous one. Used for chain detection.
b = rank_bb(r) | rank_bb(Us == WHITE ? r - Rank(1) : r + Rank(1));
// Passed, isolated, doubled or member of a pawn
// chain (but not the backward one) ?
passed = !(theirPawns & passed_pawn_mask(Us, s));
// Our rank plus previous one. Used for chain detection.
b = rank_bb(r) | rank_bb(Us == WHITE ? r - Rank(1) : r + Rank(1));
// Passed, isolated, doubled or member of a pawn
// chain (but not the backward one) ?
passed = !(theirPawns & passed_pawn_mask(Us, s));