b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them);
// Consider only squares where the enemy rook gives check
- b &= RookPseudoAttacks[ksq];
+ b &= PseudoAttacks[ROOK][ksq];
if (b)
{
for (c = WHITE; c <= BLACK; c++)
{
// Skip if other side has non-pawn pieces
- if (pos.non_pawn_material(flip(c)))
+ if (pos.non_pawn_material(~c))
continue;
b = ei.pi->passed_pawns(c);
// Compute plies to queening and check direct advancement
movesToGo = rank_distance(s, queeningSquare) - int(relative_rank(c, s) == RANK_2);
- oppMovesToGo = square_distance(pos.king_square(flip(c)), queeningSquare) - int(c != pos.side_to_move());
+ oppMovesToGo = square_distance(pos.king_square(~c), queeningSquare) - int(c != pos.side_to_move());
pathDefended = ((ei.attackedBy[c][0] & queeningPath) == queeningPath);
if (movesToGo >= oppMovesToGo && !pathDefended)
return SCORE_ZERO;
winnerSide = (pliesToQueen[WHITE] < pliesToQueen[BLACK] ? WHITE : BLACK);
- loserSide = flip(winnerSide);
+ loserSide = ~winnerSide;
// Step 3. Can the losing side possibly create a new passed pawn and thus prevent the loss?
b = candidates = pos.pieces(PAWN, loserSide);