/*
- Glaurung, a UCI chess playing engine.
- Copyright (C) 2004-2008 Tord Romstad
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008-2009 Marco Costalba
- Glaurung is free software: you can redistribute it and/or modify
+ Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
-
- Glaurung is distributed in the hope that it will be useful,
+
+ Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
-
+
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "movegen.h"
+// Simple macro to wrap a very common while loop, no facny, no flexibility,
+// hardcoded list name 'mlist' and from square 'from'.
+#define SERIALIZE_MOVES(b) while (b) (*mlist++).move = make_move(from, pop_1st_bit(&b))
////
//// Local definitions
////
namespace {
-
- int generate_white_pawn_captures(const Position &pos, MoveStack *mlist);
- int generate_black_pawn_captures(const Position &pos, MoveStack *mlist);
- int generate_white_pawn_noncaptures(const Position &pos, MoveStack *mlist);
- int generate_black_pawn_noncaptures(const Position &pos, MoveStack *mlist);
- int generate_knight_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target);
- int generate_bishop_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target);
- int generate_rook_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target);
- int generate_queen_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target);
- int generate_king_moves(const Position &pos, MoveStack *mlist,
- Square from, Bitboard target);
- int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us);
-}
+ enum CastlingSide {
+ KING_SIDE,
+ QUEEN_SIDE
+ };
+ enum MoveType {
+ CAPTURE,
+ NON_CAPTURE
+ };
-////
-//// Functions
-////
+ // Functions
+ bool castling_is_check(const Position&, CastlingSide);
+ // Helper templates
+ template<CastlingSide Side>
+ MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist);
-/// generate_captures generates() all pseudo-legal captures and queen
-/// promotions. The return value is the number of moves generated.
+ template<Color Us, Rank, Bitboard, SquareDelta>
+ MoveStack* generate_pawn_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*);
-int generate_captures(const Position &pos, MoveStack *mlist) {
- Color us = pos.side_to_move();
- Bitboard target = pos.pieces_of_color(opposite_color(us));
- int n = 0;
+ template<Color Us>
+ MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist);
- assert(pos.is_ok());
- assert(!pos.is_check());
+ template<Color Us, SquareDelta Diagonal>
+ MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces);
- if(us == WHITE)
- n += generate_white_pawn_captures(pos, mlist);
- else
- n += generate_black_pawn_captures(pos, mlist);
- n += generate_knight_moves(pos, mlist+n, us, target);
- n += generate_bishop_moves(pos, mlist+n, us, target);
- n += generate_rook_moves(pos, mlist+n, us, target);
- n += generate_queen_moves(pos, mlist+n, us, target);
- n += generate_king_moves(pos, mlist+n, pos.king_square(us), target);
+ template<Color Us>
+ MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist);
- return n;
-}
+ template<Color, Color, Bitboard, Bitboard, SquareDelta>
+ MoveStack* generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*);
+ template<Color Us, SquareDelta Direction>
+ inline Bitboard move_pawns(Bitboard p) {
-/// generate_noncaptures() generates all pseudo-legal non-captures and
-/// underpromotions. The return value is the number of moves generated.
+ if (Direction == DELTA_N)
+ return Us == WHITE ? p << 8 : p >> 8;
+ else if (Direction == DELTA_NE)
+ return Us == WHITE ? p << 9 : p >> 7;
+ else if (Direction == DELTA_NW)
+ return Us == WHITE ? p << 7 : p >> 9;
+ else
+ return p;
+ }
-int generate_noncaptures(const Position &pos, MoveStack *mlist) {
- Color us = pos.side_to_move();
- Bitboard target = pos.empty_squares();
- int n = 0;
+ // Template generate_piece_checks() with specializations
+ template<PieceType>
+ MoveStack* generate_piece_checks(const Position&, MoveStack*, Color, Bitboard, Square);
- assert(pos.is_ok());
- assert(!pos.is_check());
+ template<>
+ inline MoveStack* generate_piece_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
- if(us == WHITE)
- n += generate_white_pawn_noncaptures(pos, mlist);
- else
- n += generate_black_pawn_noncaptures(pos, mlist);
- n += generate_knight_moves(pos, mlist+n, us, target);
- n += generate_bishop_moves(pos, mlist+n, us, target);
- n += generate_rook_moves(pos, mlist+n, us, target);
- n += generate_queen_moves(pos, mlist+n, us, target);
- n += generate_king_moves(pos, mlist+n, pos.king_square(us), target);
- n += generate_castle_moves(pos, mlist+n, us);
+ if (us == WHITE)
+ return generate_pawn_checks<WHITE, BLACK, Rank8BB, Rank3BB, DELTA_N>(p, dc, ksq, m);
+ else
+ return generate_pawn_checks<BLACK, WHITE, Rank1BB, Rank6BB, DELTA_S>(p, dc, ksq, m);
- return n;
-}
+ }
+ // Template generate_piece_moves() with specializations and overloads
+ template<PieceType>
+ MoveStack* generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard);
-/// generate_checks() generates all pseudo-legal non-capturing, non-promoting
-/// checks, except castling moves (will add this later). It returns the
-/// number of generated moves.
+ template<>
+ MoveStack* generate_piece_moves<KING>(const Position&, MoveStack*, Color, Bitboard);
-int generate_checks(const Position &pos, MoveStack *mlist, Bitboard dc) {
- Color us, them;
- Square ksq, from, to;
- Bitboard empty, checkSqs, b1, b2, b3;
- int n = 0;
+ template<PieceType Piece, MoveType Type>
+ inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) {
- assert(pos.is_ok());
- assert(!pos.is_check());
+ assert(Piece == PAWN);
- us = pos.side_to_move();
- them = opposite_color(us);
+ if (Type == CAPTURE)
+ return (us == WHITE ? generate_pawn_captures<WHITE>(p, m)
+ : generate_pawn_captures<BLACK>(p, m));
+ else
+ return (us == WHITE ? generate_pawn_noncaptures<WHITE>(p, m)
+ : generate_pawn_noncaptures<BLACK>(p, m));
+ }
- ksq = pos.king_square(them);
- assert(pos.piece_on(ksq) == king_of_color(them));
+ template<PieceType>
+ MoveStack* generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard, Bitboard);
- dc = pos.discovered_check_candidates(us);
- empty = pos.empty_squares();
-
- // Pawn moves. This is somewhat messy, and we use separate code for white
- // and black, because we can't shift by negative numbers in C/C++. :-(
+ template<>
+ inline MoveStack* generate_piece_moves<PAWN>(const Position& p, MoveStack* m,
+ Color us, Bitboard t, Bitboard pnd) {
+ if (us == WHITE)
+ return generate_pawn_blocking_evasions<WHITE, RANK_8, Rank3BB, DELTA_N>(p, pnd, t, m);
+ else
+ return generate_pawn_blocking_evasions<BLACK, RANK_1, Rank6BB, DELTA_S>(p, pnd, t, m);
+ }
+}
- if(us == WHITE) {
- // Pawn moves which give discovered check. This is possible only if the
- // pawn is not on the same file as the enemy king, because we don't
- // generate captures.
- // Find all friendly pawns not on the enemy king's file:
- b1 = pos.pawns(us) & ~file_bb(ksq);
+////
+//// Functions
+////
- // Discovered checks, single pawn pushes:
- b2 = b3 = ((b1 & dc) << 8) & ~Rank8BB & empty;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_N, to);
- }
- // Discovered checks, double pawn pushes:
- b3 = ((b2 & Rank3BB) << 8) & empty;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_N - DELTA_N, to);
- }
+/// generate_captures generates() all pseudo-legal captures and queen
+/// promotions. The return value is the number of moves generated.
- // Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king:
+int generate_captures(const Position& pos, MoveStack* mlist) {
- b1 &= (~dc & neighboring_files_bb(ksq));
+ assert(pos.is_ok());
+ assert(!pos.is_check());
- // Direct checks, single pawn pushes:
- b2 = (b1 << 8) & empty;
- b3 = b2 & pos.black_pawn_attacks(ksq);
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_N, to);
- }
+ Color us = pos.side_to_move();
+ Bitboard target = pos.pieces_of_color(opposite_color(us));
+ MoveStack* mlist_start = mlist;
+
+ mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
+ mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
+ mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
+ mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
+ mlist = generate_piece_moves<PAWN, CAPTURE>(pos, mlist, us);
+ mlist = generate_piece_moves<KING>(pos, mlist, us, target);
+ return int(mlist - mlist_start);
+}
- // Direct checks, double pawn pushes:
- b3 = ((b2 & Rank3BB) << 8) & empty & pos.black_pawn_attacks(ksq);
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_N - DELTA_N, to);
- }
- }
- else { // (us == BLACK)
- // Pawn moves which give discovered check. This is possible only if the
- // pawn is not on the same file as the enemy king, because we don't
- // generate captures.
+/// generate_noncaptures() generates all pseudo-legal non-captures and
+/// underpromotions. The return value is the number of moves generated.
- // Find all friendly pawns not on the enemy king's file:
- b1 = pos.pawns(us) & ~file_bb(ksq);
+int generate_noncaptures(const Position& pos, MoveStack* mlist) {
- // Discovered checks, single pawn pushes:
- b2 = b3 = ((b1 & dc) >> 8) & ~Rank1BB & empty;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_S, to);
- }
+ assert(pos.is_ok());
+ assert(!pos.is_check());
- // Discovered checks, double pawn pushes:
- b3 = ((b2 & Rank6BB) >> 8) & empty;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_S - DELTA_S, to);
- }
+ Color us = pos.side_to_move();
+ Bitboard target = pos.empty_squares();
+ MoveStack* mlist_start = mlist;
+
+ mlist = generate_piece_moves<PAWN, NON_CAPTURE>(pos, mlist, us);
+ mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, target);
+ mlist = generate_piece_moves<BISHOP>(pos, mlist, us, target);
+ mlist = generate_piece_moves<ROOK>(pos, mlist, us, target);
+ mlist = generate_piece_moves<QUEEN>(pos, mlist, us, target);
+ mlist = generate_piece_moves<KING>(pos, mlist, us, target);
+ mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
+ mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
+ return int(mlist - mlist_start);
+}
- // Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king:
- b1 &= (~dc & neighboring_files_bb(ksq));
+/// generate_non_capture_checks() generates all pseudo-legal non-capturing,
+/// non-promoting checks. It returns the number of generated moves.
- // Direct checks, single pawn pushes:
- b2 = (b1 >> 8) & empty;
- b3 = b2 & pos.white_pawn_attacks(ksq);
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_S, to);
- }
+int generate_non_capture_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
- // Direct checks, double pawn pushes:
- b3 = ((b2 & Rank6BB) >> 8) & empty & pos.black_pawn_attacks(ksq);
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - DELTA_S - DELTA_S, to);
- }
- }
+ assert(pos.is_ok());
+ assert(!pos.is_check());
- // Knight moves
- b1 = pos.knights(us);
- if(b1) {
- // Discovered knight checks:
- b2 = b1 & dc;
- while(b2) {
- from = pop_1st_bit(&b2);
- b3 = pos.knight_attacks(from) & empty;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Direct knight checks:
- b2 = b1 & ~dc;
- checkSqs = pos.knight_attacks(ksq) & empty;
- while(b2) {
- from = pop_1st_bit(&b2);
- b3 = pos.knight_attacks(from) & checkSqs;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(from, to);
- }
- }
- }
+ Color us = pos.side_to_move();
+ Square ksq = pos.king_square(opposite_color(us));
+ MoveStack* mlist_start = mlist;
+
+ assert(pos.piece_on(ksq) == piece_of_color_and_type(opposite_color(us), KING));
+
+ // Pieces moves
+ mlist = generate_piece_checks<PAWN>(pos, mlist, us, dc, ksq);
+ mlist = generate_piece_checks<KNIGHT>(pos, mlist, us, dc, ksq);
+ mlist = generate_piece_checks<BISHOP>(pos, mlist, us, dc, ksq);
+ mlist = generate_piece_checks<ROOK>(pos, mlist, us, dc, ksq);
+ mlist = generate_piece_checks<QUEEN>(pos, mlist, us, dc, ksq);
+ mlist = generate_piece_checks<KING>(pos, mlist, us, dc, ksq);
+
+ // Castling moves that give check. Very rare but nice to have!
+ if ( pos.can_castle_queenside(us)
+ && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_D)
+ && castling_is_check(pos, QUEEN_SIDE))
+ mlist = generate_castle_moves<QUEEN_SIDE>(pos, mlist);
+
+ if ( pos.can_castle_kingside(us)
+ && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_F)
+ && castling_is_check(pos, KING_SIDE))
+ mlist = generate_castle_moves<KING_SIDE>(pos, mlist);
+
+ return int(mlist - mlist_start);
+}
- // Bishop moves
- b1 = pos.bishops(us);
- if(b1) {
- // Discovered bishop checks:
- b2 = b1 & dc;
- while(b2) {
- from = pop_1st_bit(&b2);
- b3 = pos.bishop_attacks(from) & empty;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Direct bishop checks:
- b2 = b1 & ~dc;
- checkSqs = pos.bishop_attacks(ksq) & empty;
- while(b2) {
- from = pop_1st_bit(&b2);
- b3 = pos.bishop_attacks(from) & checkSqs;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(from, to);
- }
- }
- }
- // Rook moves
- b1 = pos.rooks(us);
- if(b1) {
- // Discovered rook checks:
- b2 = b1 & dc;
- while(b2) {
- from = pop_1st_bit(&b2);
- b3 = pos.rook_attacks(from) & empty;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Direct rook checks:
- b2 = b1 & ~dc;
- checkSqs = pos.rook_attacks(ksq) & empty;
- while(b2) {
- from = pop_1st_bit(&b2);
- b3 = pos.rook_attacks(from) & checkSqs;
- while(b3) {
- to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(from, to);
- }
- }
- }
+/// generate_evasions() generates all check evasions when the side to move is
+/// in check. Unlike the other move generation functions, this one generates
+/// only legal moves. It returns the number of generated moves.
- // Queen moves
- b1 = pos.queens(us);
- if(b1) {
- // Discovered queen checks are impossible!
-
- // Direct queen checks:
- checkSqs = pos.queen_attacks(ksq) & empty;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.queen_attacks(from) & checkSqs;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
- }
- }
+int generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned) {
- // King moves
- from = pos.king_square(us);
- if(bit_is_set(dc, from)) {
- b1 = pos.king_attacks(from) & empty & ~QueenPseudoAttacks[ksq];
- while(b1) {
- to = pop_1st_bit(&b1);
- mlist[n++].move = make_move(from, to);
- }
- }
+ assert(pos.is_ok());
+ assert(pos.is_check());
- // TODO: Castling moves!
-
- return n;
-}
+ Square from, to;
+ Color us = pos.side_to_move();
+ Color them = opposite_color(us);
+ Square ksq = pos.king_square(us);
+ MoveStack* mlist_start = mlist;
+ assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING));
-/// generate_evasions() generates all check evasions when the side to move is
-/// in check. Unlike the other move generation functions, this one generates
-/// only legal moves. It returns the number of generated moves. This
-/// function is very ugly, and needs cleaning up some time later. FIXME
+ // The bitboard of occupied pieces without our king
+ Bitboard b_noKing = pos.occupied_squares();
+ clear_bit(&b_noKing, ksq);
-int generate_evasions(const Position &pos, MoveStack *mlist) {
- Color us, them;
+ // Find squares attacked by slider checkers, we will
+ // remove them from king evasions set so to avoid a couple
+ // of cycles in the slow king evasions legality check loop
+ // and to be able to use square_is_attacked().
Bitboard checkers = pos.checkers();
- Bitboard pinned, b1, b2;
- Square ksq, from, to;
- int n = 0;
-
- assert(pos.is_ok());
- assert(pos.is_check());
+ Bitboard checkersAttacks = EmptyBoardBB;
+ Bitboard b = checkers & (pos.queens() | pos.bishops());
+ while (b)
+ {
+ from = pop_1st_bit(&b);
+ checkersAttacks |= bishop_attacks_bb(from, b_noKing);
+ }
- us = pos.side_to_move();
- them = opposite_color(us);
-
- ksq = pos.king_square(us);
- assert(pos.piece_on(ksq) == king_of_color(us));
-
- // Generate evasions for king:
- b1 = pos.king_attacks(ksq) & ~pos.pieces_of_color(us);
- b2 = pos.occupied_squares();
- clear_bit(&b2, ksq);
- while(b1) {
- to = pop_1st_bit(&b1);
-
- // Make sure to is not attacked by the other side. This is a bit ugly,
- // because we can't use Position::square_is_attacked. Instead we use
- // the low-level bishop_attacks_bb and rook_attacks_bb with the bitboard
- // b2 (the occupied squares with the king removed) in order to test whether
- // the king will remain in check on the destination square.
- if(((pos.pawn_attacks(us, to) & pos.pawns(them)) == EmptyBoardBB) &&
- ((pos.knight_attacks(to) & pos.knights(them)) == EmptyBoardBB) &&
- ((pos.king_attacks(to) & pos.kings(them)) == EmptyBoardBB) &&
- ((bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them))
- == EmptyBoardBB) &&
- ((rook_attacks_bb(to, b2) & pos.rooks_and_queens(them)) == EmptyBoardBB))
- mlist[n++].move = make_move(ksq, to);
+ b = checkers & (pos.queens() | pos.rooks());
+ while (b)
+ {
+ from = pop_1st_bit(&b);
+ checkersAttacks |= rook_attacks_bb(from, b_noKing);
}
+ // Generate evasions for king
+ Bitboard b1 = pos.piece_attacks<KING>(ksq) & ~pos.pieces_of_color(us) & ~checkersAttacks;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ // Note that we can use square_is_attacked() only because we
+ // have already removed slider checkers.
+ if (!pos.square_is_attacked(to, them))
+ (*mlist++).move = make_move(ksq, to);
+ }
- // Generate evasions for other pieces only if not double check. We use a
+ // Generate evasions for other pieces only if not double check. We use a
// simple bit twiddling hack here rather than calling count_1s in order to
// save some time (we know that pos.checkers() has at most two nonzero bits).
- if(!(checkers & (checkers - 1))) {
- Square checksq = first_1(checkers);
- assert(pos.color_of_piece_on(checksq) == them);
-
- // Find pinned pieces:
- pinned = pos.pinned_pieces(us);
-
- // Generate captures of the checking piece:
-
- // Pawn captures:
- b1 = pos.pawn_attacks(them, checksq) & pos.pawns(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- if(pawn_rank(us, checksq) == RANK_8) {
- mlist[n++].move = make_promotion_move(from, checksq, QUEEN);
- mlist[n++].move = make_promotion_move(from, checksq, ROOK);
- mlist[n++].move = make_promotion_move(from, checksq, BISHOP);
- mlist[n++].move = make_promotion_move(from, checksq, KNIGHT);
+ if (!(checkers & (checkers - 1))) // Only one bit set?
+ {
+ Square checksq = first_1(checkers);
+
+ assert(pos.color_of_piece_on(checksq) == them);
+
+ // Generate captures of the checking piece
+
+ // Pawn captures
+ b1 = pos.pawn_attacks(them, checksq) & pos.pawns(us) & ~pinned;
+ while (b1)
+ {
+ from = pop_1st_bit(&b1);
+ if (relative_rank(us, checksq) == RANK_8)
+ {
+ (*mlist++).move = make_promotion_move(from, checksq, QUEEN);
+ (*mlist++).move = make_promotion_move(from, checksq, ROOK);
+ (*mlist++).move = make_promotion_move(from, checksq, BISHOP);
+ (*mlist++).move = make_promotion_move(from, checksq, KNIGHT);
+ } else
+ (*mlist++).move = make_move(from, checksq);
}
- else
- mlist[n++].move = make_move(from, checksq);
- }
-
- // Knight captures:
- b1 = pos.knight_attacks(checksq) & pos.knights(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- mlist[n++].move = make_move(from, checksq);
- }
- // Bishop and queen captures:
- b1 = pos.bishop_attacks(checksq) & pos.bishops_and_queens(us)
- & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- mlist[n++].move = make_move(from, checksq);
- }
+ // Pieces captures
+ b1 = ( (pos.piece_attacks<KNIGHT>(checksq) & pos.knights(us))
+ | (pos.piece_attacks<BISHOP>(checksq) & pos.bishops_and_queens(us))
+ | (pos.piece_attacks<ROOK>(checksq) & pos.rooks_and_queens(us)) ) & ~pinned;
- // Rook and queen captures:
- b1 = pos.rook_attacks(checksq) & pos.rooks_and_queens(us)
- & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- mlist[n++].move = make_move(from, checksq);
- }
-
- // Blocking check evasions are possible only if the checking piece is
- // a slider:
- if(checkers & pos.sliders()) {
- Bitboard blockSquares = squares_between(checksq, ksq);
- assert((pos.occupied_squares() & blockSquares) == EmptyBoardBB);
-
- // Pawn moves. Because a blocking evasion can never be a capture, we
- // only generate pawn pushes. As so often, the code for pawns is a bit
- // ugly, and uses separate clauses for white and black pawns. :-(
- if(us == WHITE) {
- // Find non-pinned pawns:
- b1 = pos.pawns(WHITE) & ~pinned;
-
- // Single pawn pushes. We don't have to AND with empty squares here,
- // because the blocking squares will always be empty.
- b2 = (b1 << 8) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- assert(pos.piece_on(to) == EMPTY);
- if(square_rank(to) == RANK_8) {
- mlist[n++].move = make_promotion_move(to - DELTA_N, to, QUEEN);
- mlist[n++].move = make_promotion_move(to - DELTA_N, to, ROOK);
- mlist[n++].move = make_promotion_move(to - DELTA_N, to, BISHOP);
- mlist[n++].move = make_promotion_move(to - DELTA_N, to, KNIGHT);
- }
- else
- mlist[n++].move = make_move(to - DELTA_N, to);
- }
- // Double pawn pushes.
- b2 = (((b1 << 8) & pos.empty_squares() & Rank3BB) << 8) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- assert(pos.piece_on(to) == EMPTY);
- assert(square_rank(to) == RANK_4);
- mlist[n++].move = make_move(to - DELTA_N - DELTA_N, to);
- }
- }
- else { // (us == BLACK)
- // Find non-pinned pawns:
- b1 = pos.pawns(BLACK) & ~pinned;
-
- // Single pawn pushes. We don't have to AND with empty squares here,
- // because the blocking squares will always be empty.
- b2 = (b1 >> 8) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- assert(pos.piece_on(to) == EMPTY);
- if(square_rank(to) == RANK_1) {
- mlist[n++].move = make_promotion_move(to - DELTA_S, to, QUEEN);
- mlist[n++].move = make_promotion_move(to - DELTA_S, to, ROOK);
- mlist[n++].move = make_promotion_move(to - DELTA_S, to, BISHOP);
- mlist[n++].move = make_promotion_move(to - DELTA_S, to, KNIGHT);
- }
- else
- mlist[n++].move = make_move(to - DELTA_S, to);
- }
- // Double pawn pushes.
- b2 = (((b1 >> 8) & pos.empty_squares() & Rank6BB) >> 8) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- assert(pos.piece_on(to) == EMPTY);
- assert(square_rank(to) == RANK_5);
- mlist[n++].move = make_move(to - DELTA_S - DELTA_S, to);
- }
+ while (b1)
+ {
+ from = pop_1st_bit(&b1);
+ (*mlist++).move = make_move(from, checksq);
}
- // Knight moves
- b1 = pos.knights(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.knight_attacks(from) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Bishop moves
- b1 = pos.bishops(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.bishop_attacks(from) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Rook moves
- b1 = pos.rooks(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.rook_attacks(from) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Queen moves
- b1 = pos.queens(us) & ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
- b2 = pos.queen_attacks(from) & blockSquares;
- while(b2) {
- to = pop_1st_bit(&b2);
- mlist[n++].move = make_move(from, to);
- }
+ // Blocking check evasions are possible only if the checking piece is
+ // a slider.
+ if (checkers & pos.sliders())
+ {
+ Bitboard blockSquares = squares_between(checksq, ksq);
+
+ assert((pos.occupied_squares() & blockSquares) == EmptyBoardBB);
+
+ if (blockSquares != EmptyBoardBB)
+ {
+ mlist = generate_piece_moves<PAWN>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_moves<KNIGHT>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_moves<BISHOP>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_moves<ROOK>(pos, mlist, us, blockSquares, pinned);
+ mlist = generate_piece_moves<QUEEN>(pos, mlist, us, blockSquares, pinned);
+ }
}
- }
- // Finally, the ugly special case of en passant captures. An en passant
- // capture can only be a check evasion if the check is not a discovered
- // check. If pos.ep_square() is set, the last move made must have been
- // a double pawn push. If, furthermore, the checking piece is a pawn,
- // an en passant check evasion may be possible.
- if(pos.ep_square() != SQ_NONE && (checkers & pos.pawns(them))) {
- to = pos.ep_square();
- b1 = pos.pawn_attacks(them, to) & pos.pawns(us);
- assert(b1 != EmptyBoardBB);
- b1 &= ~pinned;
- while(b1) {
- from = pop_1st_bit(&b1);
-
- // Before generating the move, we have to make sure it is legal.
- // This is somewhat tricky, because the two disappearing pawns may
- // cause new "discovered checks". We test this by removing the
- // two relevant bits from the occupied squares bitboard, and using
- // the low-level bitboard functions for bishop and rook attacks.
- b2 = pos.occupied_squares();
- clear_bit(&b2, from);
- clear_bit(&b2, checksq);
- if(((bishop_attacks_bb(ksq, b2) & pos.bishops_and_queens(them))
- == EmptyBoardBB) &&
- ((rook_attacks_bb(ksq, b2) & pos.rooks_and_queens(them))
- == EmptyBoardBB))
- mlist[n++].move = make_ep_move(from, to);
+ // Finally, the special case of en passant captures. An en passant
+ // capture can only be a check evasion if the check is not a discovered
+ // check. If pos.ep_square() is set, the last move made must have been
+ // a double pawn push. If, furthermore, the checking piece is a pawn,
+ // an en passant check evasion may be possible.
+ if (pos.ep_square() != SQ_NONE && (checkers & pos.pawns(them)))
+ {
+ to = pos.ep_square();
+ b1 = pos.pawn_attacks(them, to) & pos.pawns(us);
+
+ // The checking pawn cannot be a discovered (bishop) check candidate
+ // otherwise we were in check also before last double push move.
+ assert(!bit_is_set(pos.discovered_check_candidates(them), checksq));
+ assert(count_1s(b1) == 1 || count_1s(b1) == 2);
+
+ b1 &= ~pinned;
+ while (b1)
+ {
+ from = pop_1st_bit(&b1);
+ // Move is always legal because checking pawn is not a discovered
+ // check candidate and our capturing pawn has been already tested
+ // against pinned pieces.
+ (*mlist++).move = make_ep_move(from, to);
+ }
}
- }
}
-
- return n;
+ return int(mlist - mlist_start);
}
/// generate_legal_moves() computes a complete list of legal moves in the
-/// current position. This function is not very fast, and should be used
-/// only in situations where performance is unimportant. It wouldn't be
+/// current position. This function is not very fast, and should be used
+/// only in situations where performance is unimportant. It wouldn't be
/// very hard to write an efficient legal move generator, but for the moment
/// we don't need it.
-int generate_legal_moves(const Position &pos, MoveStack *mlist) {
+int generate_legal_moves(const Position& pos, MoveStack* mlist) {
+
assert(pos.is_ok());
- if(pos.is_check())
- return generate_evasions(pos, mlist);
- else {
- int i, n;
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+ Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
- // Generate pseudo-legal moves:
- n = generate_captures(pos, mlist);
- n += generate_noncaptures(pos, mlist + n);
+ if (pos.is_check())
+ return generate_evasions(pos, mlist, pinned);
- // Remove illegal moves from the list:
- for(i = 0; i < n; i++) {
- if(!pos.move_is_legal(mlist[i].move, pinned))
- mlist[i--].move = mlist[--n].move;
- }
+ // Generate pseudo-legal moves
+ int n = generate_captures(pos, mlist);
+ n += generate_noncaptures(pos, mlist + n);
- return n;
- }
+ // Remove illegal moves from the list
+ for (int i = 0; i < n; i++)
+ if (!pos.pl_move_is_legal(mlist[i].move, pinned))
+ mlist[i--].move = mlist[--n].move;
+
+ return n;
}
-/// generate_move_if_legal() takes a position and a (not necessarily
-/// pseudo-legal) move and a pinned pieces bitboard as input, and tests
-/// whether the move is legal. If the move is legal, the move itself is
-/// returned. If not, the function returns MOVE_NONE. This function must
+/// move_is_legal() takes a position and a (not necessarily pseudo-legal)
+/// move and a pinned pieces bitboard as input, and tests whether
+/// the move is legal. If the move is legal, the move itself is
+/// returned. If not, the function returns false. This function must
/// only be used when the side to move is not in check.
-Move generate_move_if_legal(const Position &pos, Move m, Bitboard pinned) {
- Color us, them;
- Square from, to;
- Piece pc;
+bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) {
assert(pos.is_ok());
assert(!pos.is_check());
assert(move_is_ok(m));
+ assert(pinned == pos.pinned_pieces(pos.side_to_move()));
- us = pos.side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- pc = pos.piece_on(from);
+ Color us = pos.side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Piece pc = pos.piece_on(from);
// If the from square is not occupied by a piece belonging to the side to
// move, the move is obviously not legal.
- if(color_of_piece(pc) != us )
- return MOVE_NONE;
-
- to = move_to(m);
+ if (color_of_piece(pc) != us)
+ return false;
- // En passant moves:
- if(move_is_ep(m)) {
+ Square to = move_to(m);
- // The piece must be a pawn:
- if(type_of_piece(pc) != PAWN)
- return MOVE_NONE;
+ // En passant moves
+ if (move_is_ep(m))
+ {
+ // The piece must be a pawn and destination square must be the
+ // en passant square.
+ if ( type_of_piece(pc) != PAWN
+ || to != pos.ep_square())
+ return false;
- // The destination square must be the en passant square:
- if(to != pos.ep_square())
- return MOVE_NONE;
+ assert(pos.square_is_empty(to));
+ assert(pos.piece_on(to - pawn_push(us)) == piece_of_color_and_type(them, PAWN));
- assert(pos.square_is_empty(to));
- assert(pos.piece_on(to - pawn_push(us)) == pawn_of_color(them));
-
- // The move is pseudo-legal. If it is legal, return it.
- if(pos.move_is_legal(m))
- return m;
- else
- return MOVE_NONE;
+ // The move is pseudo-legal, check if it is also legal
+ return pos.pl_move_is_legal(m, pinned);
}
- // Castling moves:
- else if(move_is_short_castle(m)) {
-
- // The piece must be a king:
- if(type_of_piece(pc) != KING)
- return MOVE_NONE;
-
- // The side to move must still have the right to castle kingside:
- if(!pos.can_castle_kingside(us))
- return MOVE_NONE;
+ // Castling moves
+ if (move_is_short_castle(m))
+ {
+ // The piece must be a king and side to move must still have
+ // the right to castle kingside.
+ if ( type_of_piece(pc) != KING
+ ||!pos.can_castle_kingside(us))
+ return false;
+
+ assert(from == pos.king_square(us));
+ assert(to == pos.initial_kr_square(us));
+ assert(pos.piece_on(to) == piece_of_color_and_type(us, ROOK));
+
+ Square g1 = relative_square(us, SQ_G1);
+ Square f1 = relative_square(us, SQ_F1);
+ Square s;
+ bool illegal = false;
+
+ // Check if any of the squares between king and rook
+ // is occupied or under attack.
+ for (s = Min(from, g1); s <= Max(from, g1); s++)
+ if ( (s != from && s != to && !pos.square_is_empty(s))
+ || pos.square_is_attacked(s, them))
+ illegal = true;
+
+ // Check if any of the squares between king and rook
+ // is occupied.
+ for (s = Min(to, f1); s <= Max(to, f1); s++)
+ if (s != from && s != to && !pos.square_is_empty(s))
+ illegal = true;
+
+ return !illegal;
+ }
- assert(from == pos.king_square(us));
- assert(to == pos.initial_kr_square(us));
- assert(pos.piece_on(to) == rook_of_color(us));
+ if (move_is_long_castle(m))
+ {
+ // The piece must be a king and side to move must still have
+ // the right to castle kingside.
+ if ( type_of_piece(pc) != KING
+ ||!pos.can_castle_queenside(us))
+ return false;
+
+ assert(from == pos.king_square(us));
+ assert(to == pos.initial_qr_square(us));
+ assert(pos.piece_on(to) == piece_of_color_and_type(us, ROOK));
+
+ Square c1 = relative_square(us, SQ_C1);
+ Square d1 = relative_square(us, SQ_D1);
+ Square s;
+ bool illegal = false;
+
+ for (s = Min(from, c1); s <= Max(from, c1); s++)
+ if( (s != from && s != to && !pos.square_is_empty(s))
+ || pos.square_is_attacked(s, them))
+ illegal = true;
- Square g1 = relative_square(us, SQ_G1);
- Square f1 = relative_square(us, SQ_F1);
- Square s;
- bool illegal = false;
+ for (s = Min(to, d1); s <= Max(to, d1); s++)
+ if(s != from && s != to && !pos.square_is_empty(s))
+ illegal = true;
- for(s = Min(from, g1); s <= Max(from, g1); s++)
- if((s != from && s != to && !pos.square_is_empty(s)) ||
- pos.square_is_attacked(s, them))
- illegal = true;
- for(s = Min(to, f1); s <= Max(to, f1); s++)
- if(s != from && s != to && !pos.square_is_empty(s))
- illegal = true;
+ if ( square_file(to) == FILE_B
+ && ( pos.piece_on(to + DELTA_W) == piece_of_color_and_type(them, ROOK)
+ || pos.piece_on(to + DELTA_W) == piece_of_color_and_type(them, QUEEN)))
+ illegal = true;
- if(!illegal)
- return m;
- else
- return MOVE_NONE;
- }
- else if(move_is_long_castle(m)) {
-
- // The piece must be a king:
- if(type_of_piece(pc) != KING)
- return MOVE_NONE;
-
- // The side to move must still have the right to castle kingside:
- if(!pos.can_castle_queenside(us))
- return MOVE_NONE;
-
- assert(from == pos.king_square(us));
- assert(to == pos.initial_qr_square(us));
- assert(pos.piece_on(to) == rook_of_color(us));
-
- Square c1 = relative_square(us, SQ_C1);
- Square d1 = relative_square(us, SQ_D1);
- Square s;
- bool illegal = false;
-
- for(s = Min(from, c1); s <= Max(from, c1); s++)
- if((s != from && s != to && !pos.square_is_empty(s)) ||
- pos.square_is_attacked(s, them))
- illegal = true;
- for(s = Min(to, d1); s <= Max(to, d1); s++)
- if(s != from && s != to && !pos.square_is_empty(s))
- illegal = true;
- if(square_file(to) == FILE_B &&
- (pos.piece_on(to + DELTA_W) == rook_of_color(them) ||
- pos.piece_on(to + DELTA_W) == queen_of_color(them)))
- illegal = true;
-
- if(!illegal)
- return m;
- else
- return MOVE_NONE;
+ return !illegal;
}
// Normal moves
- else {
-
- // The destination square cannot be occupied by a friendly piece:
- if(pos.color_of_piece_on(to) == us)
- return MOVE_NONE;
-
- // Proceed according to the type of the moving piece.
- switch(type_of_piece(pc)) {
-
- case PAWN:
- // Pawn moves, as usual, are somewhat messy.
- if(us == WHITE) {
- // If the destination square is on the 8th rank, the move must be a
- // promotion.
- if(square_rank(to) == RANK_8 && !move_promotion(m))
- return MOVE_NONE;
-
- // Proceed according to the square delta between the source and
- // destionation squares.
- switch(to - from) {
-
- case DELTA_NW: case DELTA_NE:
- // Capture. The destination square must be occupied by an enemy piece
- // (en passant captures was handled earlier).
- if(pos.color_of_piece_on(to) != them)
- return MOVE_NONE;
- break;
- case DELTA_N:
- // Pawn push. The destination square must be empty.
- if(!pos.square_is_empty(to))
- return MOVE_NONE;
+ // The destination square cannot be occupied by a friendly piece
+ if (pos.color_of_piece_on(to) == us)
+ return false;
+
+ // Proceed according to the type of the moving piece.
+ if (type_of_piece(pc) == PAWN)
+ {
+ // Move direction must be compatible with pawn color
+ int direction = to - from;
+ if ((us == WHITE) != (direction > 0))
+ return false;
+
+ // If the destination square is on the 8/1th rank, the move must
+ // be a promotion.
+ if ( ( (square_rank(to) == RANK_8 && us == WHITE)
+ ||(square_rank(to) == RANK_1 && us != WHITE))
+ && !move_promotion(m))
+ return false;
+
+ // Proceed according to the square delta between the source and
+ // destionation squares.
+ switch (direction)
+ {
+ case DELTA_NW:
+ case DELTA_NE:
+ case DELTA_SW:
+ case DELTA_SE:
+ // Capture. The destination square must be occupied by an enemy
+ // piece (en passant captures was handled earlier).
+ if (pos.color_of_piece_on(to) != them)
+ return false;
break;
- case DELTA_NN:
- // Double pawn push. The destination square must be on the fourth
- // rank, and both the destination square and the square between the
- // source and destination squares must be empty.
- if(square_rank(to) != RANK_4 || !pos.square_is_empty(to) ||
- !pos.square_is_empty(from + DELTA_N))
- return MOVE_NONE;
- break;
-
- default:
- return MOVE_NONE;
- }
- }
- else { // (us == BLACK)
- // If the destination square is on the 1st rank, the move must be a
- // promotion.
- if(square_rank(to) == RANK_1 && !move_promotion(m))
- return MOVE_NONE;
-
- // Proceed according to the square delta between the source and
- // destionation squares.
- switch(to - from) {
-
- case DELTA_SW: case DELTA_SE:
- // Capture. The destination square must be occupied by an enemy piece
- // (en passant captures was handled earlier).
- if(pos.color_of_piece_on(to) != them)
- return MOVE_NONE;
- break;
-
- case DELTA_S:
- // Pawn push. The destination square must be empty.
- if(!pos.square_is_empty(to))
- return MOVE_NONE;
+ case DELTA_N:
+ case DELTA_S:
+ // Pawn push. The destination square must be empty.
+ if (!pos.square_is_empty(to))
+ return false;
break;
-
- case DELTA_SS:
- // Double pawn push. The destination square must be on the fifth
- // rank, and both the destination square and the square between the
- // source and destination squares must be empty.
- if(square_rank(to) != RANK_5 || !pos.square_is_empty(to) ||
- !pos.square_is_empty(from + DELTA_S))
- return MOVE_NONE;
- break;
-
- default:
- return MOVE_NONE;
- }
- }
- // The move is pseudo-legal. Return it if it is legal.
- if(pos.move_is_legal(m))
- return m;
- else
- return MOVE_NONE;
- break;
- case KNIGHT:
- if(pos.knight_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- case BISHOP:
- if(pos.bishop_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- case ROOK:
- if(pos.rook_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
-
- case QUEEN:
- if(pos.queen_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
+ case DELTA_NN:
+ // Double white pawn push. The destination square must be on the fourth
+ // rank, and both the destination square and the square between the
+ // source and destination squares must be empty.
+ if ( square_rank(to) != RANK_4
+ || !pos.square_is_empty(to)
+ || !pos.square_is_empty(from + DELTA_N))
+ return false;
+ break;
- case KING:
- if(pos.king_attacks_square(from, to) && pos.move_is_legal(m) &&
- !move_promotion(m))
- return m;
- else
- return MOVE_NONE;
- break;
+ case DELTA_SS:
+ // Double black pawn push. The destination square must be on the fifth
+ // rank, and both the destination square and the square between the
+ // source and destination squares must be empty.
+ if ( square_rank(to) != RANK_5
+ || !pos.square_is_empty(to)
+ || !pos.square_is_empty(from + DELTA_S))
+ return false;
+ break;
- default:
- assert(false);
- }
+ default:
+ return false;
+ }
+ // The move is pseudo-legal, check if it is also legal
+ return pos.pl_move_is_legal(m, pinned);
}
- assert(false);
- return MOVE_NONE;
+ // Luckly we can handle all the other pieces in one go
+ return ( pos.piece_attacks_square(pos.piece_on(from), from, to)
+ && pos.pl_move_is_legal(m, pinned)
+ && !move_promotion(m));
}
namespace {
- int generate_white_pawn_captures(const Position &pos, MoveStack *mlist) {
- Bitboard pawns = pos.pawns(WHITE);
- Bitboard enemyPieces = pos.pieces_of_color(BLACK);
- Bitboard b1, b2;
- Square sq;
- int n = 0;
-
- // Captures in the a1-h8 direction:
- b1 = (pawns << 9) & ~FileABB & enemyPieces;
+ template<PieceType Piece>
+ MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
- // Promotions:
- b2 = b1 & Rank8BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, QUEEN);
- }
+ Square from;
+ Bitboard b;
- // Non-promotions:
- b2 = b1 & ~Rank8BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_NE, sq);
+ for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++)
+ {
+ from = pos.piece_list(us, Piece, i);
+ b = pos.piece_attacks<Piece>(from) & target;
+ SERIALIZE_MOVES(b);
}
+ return mlist;
+ }
- // Captures in the h1-a8 direction:
- b1 = (pawns << 7) & ~FileHBB & enemyPieces;
+ template<PieceType Piece>
+ MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist,
+ Color us, Bitboard target, Bitboard pinned) {
+ Square from;
+ Bitboard b;
- // Promotions:
- b2 = b1 & Rank8BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, QUEEN);
- }
+ for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++)
+ {
+ from = pos.piece_list(us, Piece, i);
+ if (pinned && bit_is_set(pinned, from))
+ continue;
- // Non-promotions:
- b2 = b1 & ~Rank8BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_NW, sq);
+ b = pos.piece_attacks<Piece>(from) & target;
+ SERIALIZE_MOVES(b);
}
+ return mlist;
+ }
- // Non-capturing promotions:
- b1 = (pawns << 8) & pos.empty_squares() & Rank8BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, QUEEN);
- }
+ template<>
+ MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
- // En passant captures:
- if(pos.ep_square() != SQ_NONE) {
- assert(square_rank(pos.ep_square()) == RANK_6);
- b1 = pawns & pos.black_pawn_attacks(pos.ep_square());
- assert(b1 != EmptyBoardBB);
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_ep_move(sq, pos.ep_square());
- }
- }
+ Bitboard b;
+ Square from = pos.king_square(us);
- return n;
+ b = pos.piece_attacks<KING>(from) & target;
+ SERIALIZE_MOVES(b);
+ return mlist;
}
+ template<Color Us, SquareDelta Diagonal>
+ MoveStack* generate_pawn_captures_diagonal(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces) {
- int generate_black_pawn_captures(const Position &pos, MoveStack *mlist) {
- Bitboard pawns = pos.pawns(BLACK);
- Bitboard enemyPieces = pos.pieces_of_color(WHITE);
- Bitboard b1, b2;
- Square sq;
- int n = 0;
+ // Calculate our parametrized parameters at compile time
+ const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
+ const Bitboard TFileABB = (Diagonal == DELTA_NE ? FileABB : FileHBB);
+ const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
+ const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
+ const SquareDelta TTDELTA_NE = (Diagonal == DELTA_NE ? TDELTA_NE : TDELTA_NW);
- // Captures in the a8-h1 direction:
- b1 = (pawns >> 7) & ~FileABB & enemyPieces;
+ Square to;
- // Promotions:
- b2 = b1 & Rank1BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, QUEEN);
- }
+ // Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black)
+ Bitboard b1 = move_pawns<Us, Diagonal>(pawns) & ~TFileABB & enemyPieces;
- // Non-promotions:
- b2 = b1 & ~Rank1BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_SE, sq);
+ // Capturing promotions
+ Bitboard b2 = b1 & TRank8BB;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN);
}
- // Captures in the h8-a1 direction:
- b1 = (pawns >> 9) & ~FileHBB & enemyPieces;
-
- // Promotions:
- b2 = b1 & Rank1BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, QUEEN);
+ // Capturing non-promotions
+ b2 = b1 & ~TRank8BB;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_move(to - TTDELTA_NE, to);
}
+ return mlist;
+ }
- // Non-promotions:
- b2 = b1 & ~Rank1BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_SW, sq);
- }
+ template<Color Us>
+ MoveStack* generate_pawn_captures(const Position& pos, MoveStack* mlist) {
- // Non-capturing promotions:
- b1 = (pawns >> 8) & pos.empty_squares() & Rank1BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, QUEEN);
- }
+ // Calculate our parametrized parameters at compile time
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
+ const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
- // En passant captures:
- if(pos.ep_square() != SQ_NONE) {
- assert(square_rank(pos.ep_square()) == RANK_3);
- b1 = pawns & pos.white_pawn_attacks(pos.ep_square());
- assert(b1 != EmptyBoardBB);
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_ep_move(sq, pos.ep_square());
- }
+ Square to;
+ Bitboard pawns = pos.pawns(Us);
+ Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
+
+ // Standard captures and capturing promotions in both directions
+ mlist = generate_pawn_captures_diagonal<Us, DELTA_NE>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures_diagonal<Us, DELTA_NW>(mlist, pawns, enemyPieces);
+
+ // Non-capturing promotions
+ Bitboard b1 = move_pawns<Us, DELTA_N>(pawns) & pos.empty_squares() & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+ }
+
+ // En passant captures
+ if (pos.ep_square() != SQ_NONE)
+ {
+ assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6);
+ assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3);
+
+ b1 = pawns & pos.pawn_attacks(Them, pos.ep_square());
+ assert(b1 != EmptyBoardBB);
+
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_ep_move(to, pos.ep_square());
+ }
}
-
- return n;
+ return mlist;
}
-
- int generate_white_pawn_noncaptures(const Position &pos, MoveStack *mlist) {
- Bitboard pawns = pos.pawns(WHITE);
- Bitboard enemyPieces = pos.pieces_of_color(BLACK);
- Bitboard emptySquares = pos.empty_squares();
- Bitboard b1, b2;
- Square sq;
- int n = 0;
-
- // Underpromotion captures in the a1-h8 direction:
- b1 = (pawns << 9) & ~FileABB & enemyPieces & Rank8BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, KNIGHT);
- }
+ template<Color Us>
+ MoveStack* generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) {
- // Underpromotion captures in the h1-a8 direction:
- b1 = (pawns << 7) & ~FileHBB & enemyPieces & Rank8BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, KNIGHT);
- }
+ // Calculate our parametrized parameters at compile time
+ const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
+ const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
+ const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
+ const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
+
+ Bitboard b1, b2;
+ Square to;
+ Bitboard pawns = pos.pawns(Us);
+ Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us));
+ Bitboard emptySquares = pos.empty_squares();
- // Single pawn pushes:
- b1 = (pawns << 8) & emptySquares;
- b2 = b1 & Rank8BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_N, sq, KNIGHT);
+ // Underpromotion captures in the a1-h8 (a8-h1 for black) direction
+ b1 = move_pawns<Us, DELTA_NE>(pawns) & ~FileABB & enemyPieces & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT);
+ }
+
+ // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
+ b1 = move_pawns<Us, DELTA_NW>(pawns) & ~FileHBB & enemyPieces & TRank8BB;
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT);
+ }
+
+ // Single pawn pushes
+ b1 = move_pawns<Us, DELTA_N>(pawns) & emptySquares;
+ b2 = b1 & TRank8BB;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
}
- b2 = b1 & ~Rank8BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_N, sq);
+ b2 = b1 & ~TRank8BB;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_move(to - TDELTA_N, to);
}
- // Double pawn pushes:
- b2 = ((b1 & Rank3BB) << 8) & emptySquares;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_N - DELTA_N, sq);
+ // Double pawn pushes
+ b2 = move_pawns<Us, DELTA_N>(b1 & TRank3BB) & emptySquares;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
}
-
- return n;
+ return mlist;
}
- int generate_black_pawn_noncaptures(const Position &pos, MoveStack *mlist) {
- Bitboard pawns = pos.pawns(BLACK);
- Bitboard enemyPieces = pos.pieces_of_color(WHITE);
- Bitboard emptySquares = pos.empty_squares();
- Bitboard b1, b2;
- Square sq;
- int n = 0;
-
- // Underpromotion captures in the a8-h1 direction:
- b1 = (pawns >> 7) & ~FileABB & enemyPieces & Rank1BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, KNIGHT);
- }
+ template<Color Us, Color Them, Bitboard TRank8BB, Bitboard TRank3BB, SquareDelta TDELTA_N>
+ MoveStack* generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist)
+ {
+ Bitboard b1, b2, b3;
+ Bitboard empty = pos.empty_squares();
+
+ if (dc != EmptyBoardBB)
+ {
+ // Pawn moves which gives discovered check. This is possible only if the
+ // pawn is not on the same file as the enemy king, because we don't
+ // generate captures.
+ b1 = pos.pawns(Us) & ~file_bb(ksq);
+
+ // Discovered checks, single pawn pushes, no promotions
+ b2 = b3 = move_pawns<Us, DELTA_N>(b1 & dc) & empty & ~TRank8BB;
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ (*mlist++).move = make_move(to - TDELTA_N, to);
+ }
- // Underpromotion captures in the h8-a1 direction:
- b1 = (pawns >> 9) & ~FileHBB & enemyPieces & Rank1BB;
- while(b1) {
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, KNIGHT);
+ // Discovered checks, double pawn pushes
+ b3 = move_pawns<Us, DELTA_N>(b2 & TRank3BB) & empty;
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
+ }
}
- // Single pawn pushes:
- b1 = (pawns >> 8) & emptySquares;
- b2 = b1 & Rank1BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, ROOK);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, BISHOP);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, KNIGHT);
- }
- b2 = b1 & ~Rank1BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_S, sq);
- }
-
- // Double pawn pushes:
- b2 = ((b1 & Rank6BB) >> 8) & emptySquares;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_S - DELTA_S, sq);
- }
+ // Direct checks. These are possible only for pawns on neighboring files
+ // of the enemy king.
+ b1 = pos.pawns(Us) & neighboring_files_bb(ksq) & ~dc;
- return n;
- }
+ // Direct checks, single pawn pushes
+ b2 = move_pawns<Us, DELTA_N>(b1) & empty;
+ b3 = b2 & pos.pawn_attacks(Them, ksq);
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ (*mlist++).move = make_move(to - TDELTA_N, to);
+ }
-
- int generate_knight_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target) {
- Square from, to;
- Bitboard b;
- int i, n = 0;
-
- for(i = 0; i < pos.knight_count(side); i++) {
- from = pos.knight_list(side, i);
- b = pos.knight_attacks(from) & target;
- while(b) {
- to = pop_1st_bit(&b);
- mlist[n++].move = make_move(from, to);
- }
+ // Direct checks, double pawn pushes
+ b3 = move_pawns<Us, DELTA_N>(b2 & TRank3BB) & empty & pos.pawn_attacks(Them, ksq);
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
}
- return n;
+ return mlist;
}
+ template<PieceType Piece>
+ MoveStack* generate_piece_checks(const Position& pos, MoveStack* mlist, Color us,
+ Bitboard dc, Square ksq) {
- int generate_bishop_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target) {
- Square from, to;
- Bitboard b;
- int i, n = 0;
-
- for(i = 0; i < pos.bishop_count(side); i++) {
- from = pos.bishop_list(side, i);
- b = pos.bishop_attacks(from) & target;
- while(b) {
- to = pop_1st_bit(&b);
- mlist[n++].move = make_move(from, to);
- }
- }
- return n;
- }
+ Bitboard target = pos.pieces_of_color_and_type(us, Piece);
+ // Discovered checks
+ Bitboard b = target & dc;
+ while (b)
+ {
+ Square from = pop_1st_bit(&b);
+ Bitboard bb = pos.piece_attacks<Piece>(from) & pos.empty_squares();
+ if (Piece == KING)
+ bb &= ~QueenPseudoAttacks[ksq];
- int generate_rook_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target) {
- Square from, to;
- Bitboard b;
- int i, n = 0;
-
- for(i = 0; i < pos.rook_count(side); i++) {
- from = pos.rook_list(side, i);
- b = pos.rook_attacks(from) & target;
- while(b) {
- to = pop_1st_bit(&b);
- mlist[n++].move = make_move(from, to);
- }
+ SERIALIZE_MOVES(bb);
}
- return n;
- }
+ // Direct checks
+ b = target & ~dc;
+ if (Piece == KING || !b)
+ return mlist;
- int generate_queen_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target) {
- Square from, to;
- Bitboard b;
- int i, n = 0;
-
- for(i = 0; i < pos.queen_count(side); i++) {
- from = pos.queen_list(side, i);
- b = pos.queen_attacks(from) & target;
- while(b) {
- to = pop_1st_bit(&b);
- mlist[n++].move = make_move(from, to);
- }
+ Bitboard checkSqs = pos.piece_attacks<Piece>(ksq) & pos.empty_squares();
+ if (!checkSqs)
+ return mlist;
+
+ while (b)
+ {
+ Square from = pop_1st_bit(&b);
+ if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs))
+ || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs))
+ || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
+ continue;
+
+ Bitboard bb = pos.piece_attacks<Piece>(from) & checkSqs;
+ SERIALIZE_MOVES(bb);
}
- return n;
+ return mlist;
}
-
- int generate_king_moves(const Position &pos, MoveStack *mlist,
- Square from, Bitboard target) {
+ template<Color Us, Rank TRANK_8, Bitboard TRank3BB, SquareDelta TDELTA_N>
+ MoveStack* generate_pawn_blocking_evasions(const Position& pos, Bitboard pinned,
+ Bitboard blockSquares, MoveStack* mlist) {
Square to;
- Bitboard b;
- int n = 0;
-
- b = pos.king_attacks(from) & target;
- while(b) {
- to = pop_1st_bit(&b);
- mlist[n++].move = make_move(from, to);
+
+ // Find non-pinned pawns and push them one square
+ Bitboard b1 = move_pawns<Us, DELTA_N>(pos.pawns(Us) & ~pinned);
+
+ // We don't have to AND with empty squares here,
+ // because the blocking squares will always be empty.
+ Bitboard b2 = b1 & blockSquares;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
+
+ assert(pos.piece_on(to) == EMPTY);
+
+ if (square_rank(to) == TRANK_8)
+ {
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, ROOK);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, BISHOP);
+ (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT);
+ } else
+ (*mlist++).move = make_move(to - TDELTA_N, to);
}
- return n;
- }
+ // Double pawn pushes
+ b2 = b1 & pos.empty_squares() & TRank3BB;
+ b2 = move_pawns<Us, DELTA_N>(b2) & blockSquares;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
- int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us) {
- int n = 0;
+ assert(pos.piece_on(to) == EMPTY);
+ assert(Us != WHITE || square_rank(to) == RANK_4);
+ assert(Us != BLACK || square_rank(to) == RANK_5);
- if(pos.can_castle(us)) {
- Color them = opposite_color(us);
- Square ksq = pos.king_square(us);
- assert(pos.piece_on(ksq) == king_of_color(us));
-
- if(pos.can_castle_kingside(us)) {
- Square rsq = pos.initial_kr_square(us);
- Square g1 = relative_square(us, SQ_G1);
- Square f1 = relative_square(us, SQ_F1);
- Square s;
- bool illegal = false;
+ (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
+ }
+ return mlist;
+ }
- assert(pos.piece_on(rsq) == rook_of_color(us));
+ template<CastlingSide Side>
+ MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) {
- for(s = Min(ksq, g1); s <= Max(ksq, g1); s++)
- if((s != ksq && s != rsq && pos.square_is_occupied(s))
- || pos.square_is_attacked(s, them))
- illegal = true;
- for(s = Min(rsq, f1); s <= Max(rsq, f1); s++)
- if(s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
+ Color us = pos.side_to_move();
- if(!illegal)
- mlist[n++].move = make_castle_move(ksq, rsq);
- }
+ if ( (Side == KING_SIDE && pos.can_castle_kingside(us))
+ ||(Side == QUEEN_SIDE && pos.can_castle_queenside(us)))
+ {
+ Color them = opposite_color(us);
+ Square ksq = pos.king_square(us);
+
+ assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING));
- if(pos.can_castle_queenside(us)) {
- Square rsq = pos.initial_qr_square(us);
- Square c1 = relative_square(us, SQ_C1);
- Square d1 = relative_square(us, SQ_D1);
+ Square rsq = (Side == KING_SIDE ? pos.initial_kr_square(us) : pos.initial_qr_square(us));
+ Square s1 = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ Square s2 = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
Square s;
bool illegal = false;
- assert(pos.piece_on(rsq) == rook_of_color(us));
+ assert(pos.piece_on(rsq) == piece_of_color_and_type(us, ROOK));
- for(s = Min(ksq, c1); s <= Max(ksq, c1); s++)
- if((s != ksq && s != rsq && pos.square_is_occupied(s))
- || pos.square_is_attacked(s, them))
- illegal = true;
- for(s = Min(rsq, d1); s <= Max(rsq, d1); s++)
- if(s != ksq && s != rsq && pos.square_is_occupied(s))
+ // It is a bit complicated to correctly handle Chess960
+ for (s = Min(ksq, s1); s <= Max(ksq, s1); s++)
+ if ( (s != ksq && s != rsq && pos.square_is_occupied(s))
+ || pos.square_is_attacked(s, them))
+ illegal = true;
+
+ for (s = Min(rsq, s2); s <= Max(rsq, s2); s++)
+ if (s != ksq && s != rsq && pos.square_is_occupied(s))
+ illegal = true;
+
+ if ( Side == QUEEN_SIDE
+ && square_file(rsq) == FILE_B
+ && ( pos.piece_on(relative_square(us, SQ_A1)) == piece_of_color_and_type(them, ROOK)
+ || pos.piece_on(relative_square(us, SQ_A1)) == piece_of_color_and_type(them, QUEEN)))
illegal = true;
- if(square_file(rsq) == FILE_B &&
- (pos.piece_on(relative_square(us, SQ_A1)) == rook_of_color(them) ||
- pos.piece_on(relative_square(us, SQ_A1)) == queen_of_color(them)))
- illegal = true;
-
- if(!illegal)
- mlist[n++].move = make_castle_move(ksq, rsq);
- }
+
+ if (!illegal)
+ (*mlist++).move = make_castle_move(ksq, rsq);
}
+ return mlist;
+ }
+
+ bool castling_is_check(const Position& pos, CastlingSide side) {
+
+ // After castling opponent king is attacked by the castled rook?
+ File rookFile = (side == QUEEN_SIDE ? FILE_D : FILE_F);
+ Color us = pos.side_to_move();
+ Square ksq = pos.king_square(us);
+ Bitboard occ = pos.occupied_squares();
- return n;
+ clear_bit(&occ, ksq); // Remove our king from the board
+ Square rsq = make_square(rookFile, square_rank(ksq));
+ return bit_is_set(rook_attacks_bb(rsq, occ), pos.king_square(opposite_color(us)));
}
-
}
projects / stockfish / blobdiff