}
- template<Color Us, PieceType Pt, bool Checks>
- ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard target) {
+ template<PieceType Pt, bool Checks>
+ ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard piecesToMove, Bitboard target) {
static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()");
- Bitboard bb = pos.pieces(Us, Pt);
+ Bitboard bb = piecesToMove & pos.pieces(Pt);
while (bb)
{
Square from = pop_lsb(bb);
Bitboard b = attacks_bb<Pt>(from, pos.pieces()) & target;
- if (Checks && (Pt == QUEEN || !(pos.blockers_for_king(~Us) & from)))
+ if constexpr (Checks)
b &= pos.check_squares(Pt);
while (b)
static_assert(Type != LEGAL, "Unsupported type in generate_all()");
constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantiations
- const Square ksq = pos.square<KING>(Us);
- Bitboard target;
-
- if (Type == EVASIONS && more_than_one(pos.checkers()))
- goto kingMoves; // Double check, only a king move can save the day
+ Bitboard target, piecesToMove = pos.pieces(Us);
+
+ if(Type == QUIET_CHECKS)
+ piecesToMove &= ~pos.blockers_for_king(~Us);
switch (Type)
{
target = ~pos.pieces();
break;
case EVASIONS:
- target = between_bb(ksq, lsb(pos.checkers()));
+ target = between_bb(pos.square<KING>(Us), lsb(pos.checkers()));
break;
case NON_EVASIONS:
target = ~pos.pieces(Us);
}
moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);
- moveList = generate_moves<Us, KNIGHT, Checks>(pos, moveList, target);
- moveList = generate_moves<Us, BISHOP, Checks>(pos, moveList, target);
- moveList = generate_moves<Us, ROOK, Checks>(pos, moveList, target);
- moveList = generate_moves<Us, QUEEN, Checks>(pos, moveList, target);
+ moveList = generate_moves<KNIGHT, Checks>(pos, moveList, piecesToMove, target);
+ moveList = generate_moves<BISHOP, Checks>(pos, moveList, piecesToMove, target);
+ moveList = generate_moves< ROOK, Checks>(pos, moveList, piecesToMove, target);
+ moveList = generate_moves< QUEEN, Checks>(pos, moveList, piecesToMove, target);
-kingMoves:
- if (!Checks || pos.blockers_for_king(~Us) & ksq)
+ if (Type != QUIET_CHECKS && Type != EVASIONS)
{
- Bitboard b = attacks_bb<KING>(ksq) & (Type == EVASIONS ? ~pos.pieces(Us) : target);
- if (Checks)
- b &= ~attacks_bb<QUEEN>(pos.square<KING>(~Us));
-
+ Square ksq = pos.square<KING>(Us);
+ Bitboard b = attacks_bb<KING>(ksq) & target;
while (b)
*moveList++ = make_move(ksq, pop_lsb(b));
- if ((Type == QUIETS || Type == NON_EVASIONS) && pos.can_castle(Us & ANY_CASTLING))
+ if ((Type != CAPTURES) && pos.can_castle(Us & ANY_CASTLING))
for (CastlingRights cr : { Us & KING_SIDE, Us & QUEEN_SIDE } )
if (!pos.castling_impeded(cr) && pos.can_castle(cr))
*moveList++ = make<CASTLING>(ksq, pos.castling_rook_square(cr));
/// <CAPTURES> Generates all pseudo-legal captures plus queen and checking knight promotions
/// <QUIETS> Generates all pseudo-legal non-captures and underpromotions (except checking knight)
-/// <EVASIONS> Generates all pseudo-legal check evasions when the side to move is in check
-/// <QUIET_CHECKS> Generates all pseudo-legal non-captures giving check, except castling
/// <NON_EVASIONS> Generates all pseudo-legal captures and non-captures
///
/// Returns a pointer to the end of the move list.
template<GenType Type>
ExtMove* generate(const Position& pos, ExtMove* moveList) {
- static_assert(Type != LEGAL, "Unsupported type in generate()");
- assert((Type == EVASIONS) == (bool)pos.checkers());
+ static_assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS, "Unsupported type in generate()");
+ assert(!pos.checkers());
Color us = pos.side_to_move();
// Explicit template instantiations
template ExtMove* generate<CAPTURES>(const Position&, ExtMove*);
template ExtMove* generate<QUIETS>(const Position&, ExtMove*);
-template ExtMove* generate<EVASIONS>(const Position&, ExtMove*);
-template ExtMove* generate<QUIET_CHECKS>(const Position&, ExtMove*);
template ExtMove* generate<NON_EVASIONS>(const Position&, ExtMove*);
+/// generate<QUIET_CHECKS> generates all pseudo-legal non-captures giving check,
+/// except castling. Returns a pointer to the end of the move list.
+template<>
+ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* moveList) {
+
+ assert(!pos.checkers());
+
+ Color us = pos.side_to_move();
+ Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us) & ~pos.pieces(PAWN);
+
+ while (dc)
+ {
+ Square from = pop_lsb(dc);
+ PieceType pt = type_of(pos.piece_on(from));
+
+ Bitboard b = attacks_bb(pt, from, pos.pieces()) & ~pos.pieces();
+
+ if (pt == KING)
+ b &= ~attacks_bb<QUEEN>(pos.square<KING>(~us));
+
+ while (b)
+ *moveList++ = make_move(from, pop_lsb(b));
+ }
+
+ return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, moveList)
+ : generate_all<BLACK, QUIET_CHECKS>(pos, moveList);
+}
+
+
+/// generate<EVASIONS> generates all pseudo-legal check evasions when the side
+/// to move is in check. Returns a pointer to the end of the move list.
+template<>
+ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* moveList) {
+
+ assert(pos.checkers());
+
+ Color us = pos.side_to_move();
+ Square ksq = pos.square<KING>(us);
+
+ // Generate evasions for king
+ Bitboard b = attacks_bb<KING>(ksq) & ~pos.pieces(us);
+ while (b)
+ *moveList++ = make_move(ksq, pop_lsb(b));
+
+ if (more_than_one(pos.checkers()))
+ return moveList; // Double check, only a king move can save the day
+
+ // Generate blocking interpositions or captures of the checking piece
+ return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, moveList)
+ : generate_all<BLACK, EVASIONS>(pos, moveList);
+}
+
+
/// generate<LEGAL> generates all the legal moves in the given position
template<>