/*
- 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 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&, MoveStack*);
- int generate_black_pawn_captures(const Position&, MoveStack*);
- int generate_white_pawn_noncaptures(const Position&, MoveStack*);
- int generate_black_pawn_noncaptures(const Position&, MoveStack*);
- int generate_piece_moves(PieceType, const Position&, MoveStack*, Color side, Bitboard t);
- int generate_castle_moves(const Position&, MoveStack*, Color us);
-
- int generate_piece_checks(PieceType pce, const Position& pos, Bitboard target,
- Bitboard dc, Square ksq, MoveStack* mlist);
+
+ enum CastlingSide {
+ KING_SIDE,
+ QUEEN_SIDE
+ };
+
+ static const bool CAPTURE = true;
+ static const bool NON_CAPTURE = false;
+
+ // Function
+ bool castling_is_check(const Position&, CastlingSide);
+
+ // Main templates
+ template<CastlingSide Side>
+ MoveStack* generate_castle_moves(const Position&, MoveStack*);
+
+ template<PieceType>
+ MoveStack* generate_piece_checks(const Position&, MoveStack*, Color us, Bitboard, Square);
+
+ // Helper templates
+ template<Color Us, Rank, Bitboard, SquareDelta>
+ MoveStack* do_generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned,
+ Bitboard blockSquares, MoveStack* mlist);
+
+ template<Color, Color, Bitboard, SquareDelta, SquareDelta, SquareDelta>
+ MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist);
+
+ template<Color, Color, Bitboard, Bitboard, SquareDelta, SquareDelta, SquareDelta>
+ MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist);
+
+ // Template generate_pawn_checks() with specializations
+ template<Color, Color, Bitboard, Bitboard, SquareDelta>
+ MoveStack* do_generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*);
+
+ template<Color>
+ inline MoveStack* generate_pawn_checks(const Position& p, MoveStack* m, Bitboard dc, Square ksq) {
+ return do_generate_pawn_checks<WHITE, BLACK, Rank8BB, Rank3BB, DELTA_N>(p, dc, ksq, m);
+ }
+ template<>
+ inline MoveStack* generate_pawn_checks<BLACK>(const Position& p, MoveStack* m, Bitboard dc, Square ksq) {
+ return do_generate_pawn_checks<BLACK, WHITE, Rank1BB, Rank6BB, DELTA_S>(p, dc, ksq, m);
+ }
+
+ // Template generate_piece_moves() with specializations
+ template<PieceType>
+ MoveStack* generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard);
+ template<>
+ MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target);
+
+ template<PieceType Piece, bool Capture>
+ inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) {
+
+ assert(Piece == PAWN);
+
+ if (Capture)
+ return (us == WHITE ? do_generate_pawn_captures<WHITE, BLACK, Rank8BB, DELTA_NE, DELTA_NW, DELTA_N>(p, m)
+ : do_generate_pawn_captures<BLACK, WHITE, Rank1BB, DELTA_SE, DELTA_SW, DELTA_S>(p, m));
+ else
+ return (us == WHITE ? do_generate_pawn_noncaptures<WHITE, BLACK, Rank8BB, Rank3BB, DELTA_NE, DELTA_NW, DELTA_N>(p, m)
+ : do_generate_pawn_noncaptures<BLACK, WHITE, Rank1BB, Rank6BB, DELTA_SE, DELTA_SW, DELTA_S>(p, m));
+ }
+
+ // Template generate_piece_blocking_evasions() with specializations
+ template<PieceType>
+ MoveStack* generate_piece_blocking_evasions(const Position&, MoveStack*, Color us, Bitboard, Bitboard);
+
+ template<>
+ MoveStack* generate_piece_blocking_evasions<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard np, Bitboard bs);
}
Color us = pos.side_to_move();
Bitboard target = pos.pieces_of_color(opposite_color(us));
- int n;
-
- if (us == WHITE)
- n = generate_white_pawn_captures(pos, mlist);
- else
- n = generate_black_pawn_captures(pos, mlist);
-
- for (PieceType pce = KNIGHT; pce <= KING; pce++)
- n += generate_piece_moves(pce, pos, mlist+n, us, target);
-
- return n;
+ 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);
}
-/// generate_noncaptures() generates all pseudo-legal non-captures and
-/// underpromotions. The return value is the number of moves generated.
+/// generate_noncaptures() generates all pseudo-legal non-captures and
+/// underpromotions. The return value is the number of moves generated.
-int generate_noncaptures(const Position& pos, MoveStack *mlist) {
+int generate_noncaptures(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
assert(!pos.is_check());
Color us = pos.side_to_move();
Bitboard target = pos.empty_squares();
- int n;
-
- if (us == WHITE)
- n = generate_white_pawn_noncaptures(pos, mlist);
- else
- n = generate_black_pawn_noncaptures(pos, mlist);
-
- for (PieceType pce = KNIGHT; pce <= KING; pce++)
- n += generate_piece_moves(pce, pos, mlist+n, us, target);
-
- n += generate_castle_moves(pos, mlist+n, us);
- return n;
+ 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);
}
/// 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.
+/// checks. It returns the number of generated moves.
int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
assert(pos.is_ok());
assert(!pos.is_check());
- Color us, them;
- Square ksq, from, to;
- Bitboard empty, b1, b2, b3;
- int n = 0;
-
- us = pos.side_to_move();
- them = opposite_color(us);
-
- ksq = pos.king_square(them);
- assert(pos.piece_on(ksq) == king_of_color(them));
+ Color us = pos.side_to_move();
+ Square ksq = pos.king_square(opposite_color(us));
+ MoveStack* mlist_start = mlist;
- 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++. :-(
+ assert(pos.piece_on(ksq) == king_of_color(opposite_color(us)));
+ // Pawn moves
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);
-
- // 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);
- }
-
- // Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king
-
- b1 &= (~dc & neighboring_files_bb(ksq));
-
- // 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);
- }
-
- // 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.
-
- // Find all friendly pawns not on the enemy king's file:
- b1 = pos.pawns(us) & ~file_bb(ksq);
-
- // 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);
- }
-
- // 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);
- }
-
- // Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king
-
- b1 &= (~dc & neighboring_files_bb(ksq));
-
- // 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);
- }
-
- // 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);
- }
- }
-
- // Knight moves
- b1 = pos.knights(us);
- if (b1)
- n += generate_piece_checks(KNIGHT, pos, b1, dc, ksq, mlist);
-
- // Bishop moves
- b1 = pos.bishops(us);
- if (b1)
- n += generate_piece_checks(BISHOP, pos, b1, dc, ksq, mlist);
-
- // Rook moves
- b1 = pos.rooks(us);
- if (b1)
- n += generate_piece_checks(ROOK, pos, b1, dc, ksq, mlist);
-
- // Queen moves
- b1 = pos.queens(us);
- if (b1)
- n += generate_piece_checks(QUEEN, pos, b1, dc, ksq, mlist);
-
- // 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);
- }
- }
-
- // TODO: Castling moves!
-
- return n;
+ mlist = generate_pawn_checks<WHITE>(pos, mlist, dc, ksq);
+ else
+ mlist = generate_pawn_checks<BLACK>(pos, mlist, dc, ksq);
+
+ // Pieces moves
+ 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);
}
/// 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
+/// only legal moves. It returns the number of generated moves. This
/// function is very ugly, and needs cleaning up some time later. FIXME
-int generate_evasions(const Position &pos, MoveStack *mlist) {
+int generate_evasions(const Position& pos, MoveStack* mlist) {
assert(pos.is_ok());
assert(pos.is_check());
- Color us, them;
- Bitboard checkers = pos.checkers();
- Bitboard pinned, b1, b2;
- Square ksq, from, to;
- int n = 0;
-
- us = pos.side_to_move();
- them = opposite_color(us);
+ Square from, to;
+ Color us = pos.side_to_move();
+ Color them = opposite_color(us);
+ Square ksq = pos.king_square(us);
+ MoveStack* mlist_start = mlist;
- 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();
+
+ // The bitboard of occupied pieces without our king
+ Bitboard 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);
+
+ // 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.
+ Bitboard checkers = pos.checkers();
+ Bitboard checkersAttacks = EmptyBoardBB;
+ Bitboard b = checkers & (pos.queens() | pos.bishops());
+ while (b)
+ {
+ from = pop_1st_bit(&b);
+ checkersAttacks |= bishop_attacks_bb(from, b2);
}
+ b = checkers & (pos.queens() | pos.rooks());
+ while (b)
+ {
+ from = pop_1st_bit(&b);
+ checkersAttacks |= rook_attacks_bb(from, b2);
+ }
+
+ // Generate evasions for king
+ Bitboard b1 = pos.piece_attacks<KING>(ksq) & ~pos.pieces_of_color(us) & ~checkersAttacks;
+ 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.piece_attacks<KNIGHT>(to) & pos.knights(them))
+ || (pos.pawn_attacks(us, to) & pos.pawns(them))
+ || (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them))
+ || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them))
+ || (pos.piece_attacks<KING>(to) & pos.kings(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(relative_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);
- }
- else
- mlist[n++].move = make_move(from, checksq);
- }
+ if (!(checkers & (checkers - 1))) // Only one bit set?
+ {
+ Square checksq = first_1(checkers);
- // 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);
- }
+ assert(pos.color_of_piece_on(checksq) == them);
- // 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);
- }
+ // Find pinned pieces
+ Bitboard not_pinned = ~pos.pinned_pieces(us);
- // 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);
- }
+ // Generate captures of the checking piece
- // 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);
- }
+ // Pawn captures
+ b1 = pos.pawn_attacks(them, checksq) & pos.pawns(us) & not_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);
}
- // 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);
- }
+ // 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)) ) & not_pinned;
+
+ while (b1)
+ {
+ from = pop_1st_bit(&b1);
+ (*mlist++).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);
+
+ // Pieces moves
+ mlist = generate_piece_blocking_evasions<PAWN>(pos, mlist, us, not_pinned, blockSquares);
+ mlist = generate_piece_blocking_evasions<KNIGHT>(pos, mlist, us, not_pinned, blockSquares);
+ mlist = generate_piece_blocking_evasions<BISHOP>(pos, mlist, us, not_pinned, blockSquares);
+ mlist = generate_piece_blocking_evasions<ROOK>(pos, mlist, us, not_pinned, blockSquares);
+ mlist = generate_piece_blocking_evasions<QUEEN>(pos, mlist, us, not_pinned, blockSquares);
}
- // Finally, the ugly special case of en passant captures. An en passant
+ // 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,
+ // 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);
- }
+ 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 &= not_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))
+ ||(rook_attacks_bb(ksq, b2) & pos.rooks_and_queens(them))))
+
+ (*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.
if (pos.is_check())
return generate_evasions(pos, mlist);
- // Generate pseudo-legal moves:
+ // Generate pseudo-legal moves
int n = generate_captures(pos, mlist);
n += generate_noncaptures(pos, mlist + n);
Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
- // Remove illegal moves from the list:
+ // Remove illegal moves from the list
for (int i = 0; i < n; i++)
- if (!pos.move_is_legal(mlist[i].move, pinned))
+ 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) {
+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()));
Color us = pos.side_to_move();
Color them = opposite_color(us);
// 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;
+ return false;
Square to = move_to(m);
// en passant square.
if ( type_of_piece(pc) != PAWN
|| to != pos.ep_square())
- return MOVE_NONE;
+ return false;
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.
- return (pos.move_is_legal(m) ? m : MOVE_NONE);
+ // The move is pseudo-legal, check if it is also legal
+ return pos.pl_move_is_legal(m, pinned);
}
// Castling moves
// the right to castle kingside.
if ( type_of_piece(pc) != KING
||!pos.can_castle_kingside(us))
- return MOVE_NONE;
+ return false;
assert(from == pos.king_square(us));
assert(to == pos.initial_kr_square(us));
if (s != from && s != to && !pos.square_is_empty(s))
illegal = true;
- return (!illegal ? m : MOVE_NONE);
+ return !illegal;
}
if (move_is_long_castle(m))
// the right to castle kingside.
if ( type_of_piece(pc) != KING
||!pos.can_castle_queenside(us))
- return MOVE_NONE;
+ return false;
assert(from == pos.king_square(us));
assert(to == pos.initial_qr_square(us));
|| pos.piece_on(to + DELTA_W) == queen_of_color(them)))
illegal = true;
- return (!illegal ? m : MOVE_NONE);
+ return !illegal;
}
// Normal moves
// The destination square cannot be occupied by a friendly piece
if (pos.color_of_piece_on(to) == us)
- return MOVE_NONE;
+ return false;
// Proceed according to the type of the moving piece.
if (type_of_piece(pc) == PAWN)
- {
+ {
// 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 MOVE_NONE;
+ return false;
// Proceed according to the square delta between the source and
// destionation squares.
// 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;
+ return false;
break;
case DELTA_N:
case DELTA_S:
// Pawn push. The destination square must be empty.
if (!pos.square_is_empty(to))
- return MOVE_NONE;
+ return false;
break;
case DELTA_NN:
if ( square_rank(to) != RANK_4
|| !pos.square_is_empty(to)
|| !pos.square_is_empty(from + DELTA_N))
- return MOVE_NONE;
+ return false;
break;
case DELTA_SS:
if ( square_rank(to) != RANK_5
|| !pos.square_is_empty(to)
|| !pos.square_is_empty(from + DELTA_S))
- return MOVE_NONE;
+ return false;
break;
default:
- return MOVE_NONE;
+ return false;
}
- // The move is pseudo-legal. Return it if it is legal.
- return (pos.move_is_legal(m) ? m : MOVE_NONE);
+ // The move is pseudo-legal, check if it is also legal
+ return pos.pl_move_is_legal(m, pinned);
}
// Luckly we can handle all the other pieces in one go
return ( pos.piece_attacks_square(from, to)
- && pos.move_is_legal(m)
- && !move_promotion(m) ? m : MOVE_NONE);
+ && pos.pl_move_is_legal(m, pinned)
+ && !move_promotion(m));
}
namespace {
- int generate_white_pawn_captures(const Position &pos, MoveStack *mlist) {
+ template<PieceType Piece>
+ MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
- Bitboard pawns = pos.pawns(WHITE);
- Bitboard enemyPieces = pos.pieces_of_color(BLACK);
- Square sq;
- int n = 0;
-
- // Captures in the a1-h8 direction
- Bitboard b1 = (pawns << 9) & ~FileABB & enemyPieces;
+ Square from;
+ Bitboard b;
- // Capturing promotions
- Bitboard b2 = b1 & Rank8BB;
- while (b2)
+ for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++)
{
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, QUEEN);
+ from = pos.piece_list(us, Piece, i);
+ b = pos.piece_attacks<Piece>(from) & target;
+ SERIALIZE_MOVES(b);
}
+ return mlist;
+ }
- // Capturing non-promotions
- b2 = b1 & ~Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_NE, sq);
- }
+ template<>
+ MoveStack* generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
- // Captures in the h1-a8 direction
- b1 = (pawns << 7) & ~FileHBB & enemyPieces;
+ Bitboard b;
+ Square from = pos.king_square(us);
- // Capturing promotions
- b2 = b1 & Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, QUEEN);
- }
+ b = pos.piece_attacks<KING>(from) & target;
+ SERIALIZE_MOVES(b);
+ return mlist;
+ }
- // Capturing non-promotions
- b2 = b1 & ~Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_NW, sq);
- }
+ template<PieceType Piece>
+ MoveStack* generate_piece_blocking_evasions(const Position& pos, MoveStack* mlist, Color us,
+ Bitboard not_pinned, Bitboard blockSquares) {
- // 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);
- }
-
- // En passant captures
- if (pos.ep_square() != SQ_NONE)
+ Bitboard b = pos.pieces_of_color_and_type(us, Piece) & not_pinned;
+ while (b)
{
- 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());
- }
+ Square from = pop_1st_bit(&b);
+ Bitboard bb = pos.piece_attacks<Piece>(from) & blockSquares;
+ SERIALIZE_MOVES(bb);
}
- return n;
+ return mlist;
}
+ template<>
+ MoveStack* generate_piece_blocking_evasions<PAWN>(const Position& p, MoveStack* m, Color us,
+ Bitboard np, Bitboard bs) {
+ if (us == WHITE)
+ return do_generate_pawn_blocking_evasions<WHITE, RANK_8, Rank3BB, DELTA_N>(p, np, bs, m);
+ else
+ return do_generate_pawn_blocking_evasions<BLACK, RANK_1, Rank6BB, DELTA_S>(p, np, bs, m);
+ }
- int generate_black_pawn_captures(const Position &pos, MoveStack *mlist) {
+ template<Color Us, Color Them, Bitboard TRank8BB, SquareDelta TDELTA_NE,
+ SquareDelta TDELTA_NW, SquareDelta TDELTA_N
+ >
+ MoveStack* do_generate_pawn_captures(const Position& pos, MoveStack* mlist) {
- Bitboard pawns = pos.pawns(BLACK);
- Bitboard enemyPieces = pos.pieces_of_color(WHITE);
- Square sq;
- int n = 0;
+ Square to;
+ Bitboard pawns = pos.pawns(Us);
+ Bitboard enemyPieces = pos.pieces_of_color(Them);
- // Captures in the a8-h1 direction
- Bitboard b1 = (pawns >> 7) & ~FileABB & enemyPieces;
+ // Captures in the a1-h8 (a8-h1 for black) direction
+ Bitboard b1 = (Us == WHITE ? pawns << 9 : pawns >> 7) & ~FileABB & enemyPieces;
// Capturing promotions
- Bitboard b2 = b1 & Rank1BB;
+ Bitboard b2 = b1 & TRank8BB;
while (b2)
{
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, QUEEN);
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, QUEEN);
}
// Capturing non-promotions
- b2 = b1 & ~Rank1BB;
+ b2 = b1 & ~TRank8BB;
while (b2)
{
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_SE, sq);
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_move(to - TDELTA_NE, to);
}
- // Captures in the h8-a1 direction
- b1 = (pawns >> 9) & ~FileHBB & enemyPieces;
+ // Captures in the h1-a8 (h8-a1 for black) direction
+ b1 = (Us == WHITE ? pawns << 7 : pawns >> 9) & ~FileHBB & enemyPieces;
// Capturing promotions
- b2 = b1 & Rank1BB;
+ b2 = b1 & TRank8BB;
while (b2)
{
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, QUEEN);
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, QUEEN);
}
- // Capturing Non-promotions
- b2 = b1 & ~Rank1BB;
+ // Capturing non-promotions
+ b2 = b1 & ~TRank8BB;
while (b2)
{
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_SW, sq);
+ to = pop_1st_bit(&b2);
+ (*mlist++).move = make_move(to - TDELTA_NW, to);
}
// Non-capturing promotions
- b1 = (pawns >> 8) & pos.empty_squares() & Rank1BB;
+ b1 = (Us == WHITE ? pawns << 8 : pawns >> 8) & pos.empty_squares() & TRank8BB;
while (b1)
{
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_promotion_move(sq - DELTA_S, sq, QUEEN);
+ 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(square_rank(pos.ep_square()) == RANK_3);
- b1 = pawns & pos.white_pawn_attacks(pos.ep_square());
+ 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)
{
- sq = pop_1st_bit(&b1);
- mlist[n++].move = make_ep_move(sq, pos.ep_square());
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_ep_move(to, pos.ep_square());
}
}
- return n;
+ return mlist;
}
+ template<Color Us, Color Them, Bitboard TRank8BB, Bitboard TRank3BB,
+ SquareDelta TDELTA_NE, SquareDelta TDELTA_NW, SquareDelta TDELTA_N
+ >
+ MoveStack* do_generate_pawn_noncaptures(const Position& pos, MoveStack* mlist) {
- int generate_white_pawn_noncaptures(const Position &pos, MoveStack *mlist) {
-
- Bitboard pawns = pos.pawns(WHITE);
- Bitboard enemyPieces = pos.pieces_of_color(BLACK);
+ Bitboard pawns = pos.pawns(Us);
+ Bitboard enemyPieces = pos.pieces_of_color(Them);
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);
+ Square to;
+
+ // Underpromotion captures in the a1-h8 (a8-h1 for black) direction
+ b1 = (Us == WHITE ? pawns << 9 : pawns >> 7) & ~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 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);
+ // Underpromotion captures in the h1-a8 (h8-a1 for black) direction
+ b1 = (Us == WHITE ? pawns << 7 : pawns >> 9) & ~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 = (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);
+ // Single pawn pushes
+ b1 = (Us == WHITE ? pawns << 8 : pawns >> 8) & 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 = (Us == WHITE ? (b1 & TRank3BB) << 8 : (b1 & TRank3BB) >> 8) & 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* do_generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist)
+ {
+ // Find all friendly pawns not on the enemy king's file
+ Bitboard b1, b2, b3;
+ Bitboard empty = pos.empty_squares();
- // 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);
- }
+ 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 = (Us == WHITE ? (b1 & dc) << 8 : (b1 & dc) >> 8) & empty & ~TRank8BB;
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ (*mlist++).move = make_move(to - 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);
+ // Discovered checks, double pawn pushes
+ b3 = (Us == WHITE ? (b2 & TRank3BB) << 8 : (b2 & TRank3BB) >> 8) & empty;
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
+ }
}
-
- // 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;
+
+ // Direct checks, single pawn pushes
+ b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & empty;
+ b3 = b2 & pos.pawn_attacks(Them, ksq);
+ while (b3)
+ {
+ Square to = pop_1st_bit(&b3);
+ (*mlist++).move = make_move(to - TDELTA_N, to);
}
- return n;
+ // Direct checks, double pawn pushes
+ b3 = (Us == WHITE ? (b2 & TRank3BB) << 8 : (b2 & TRank3BB) >> 8)
+ & 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 mlist;
}
+ template<PieceType Piece>
+ MoveStack* generate_piece_checks(const Position& pos, MoveStack* mlist, Color us,
+ Bitboard dc, Square ksq) {
- int generate_piece_moves(PieceType piece, const Position &pos, MoveStack *mlist,
- Color side, Bitboard target) {
+ Bitboard target = pos.pieces_of_color_and_type(us, Piece);
- const Piece_attacks_fn mem_fn = piece_attacks_fn[piece];
- Square from, to;
- Bitboard b;
- int n = 0;
+ // 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];
+
+ SERIALIZE_MOVES(bb);
+ }
+
+ // Direct checks
+ b = target & ~dc;
+ if (Piece == KING || !b)
+ return mlist;
- for (int i = 0; i < pos.piece_count(side, piece); i++)
+ Bitboard checkSqs = pos.piece_attacks<Piece>(ksq) & pos.empty_squares();
+ while (b)
{
- from = pos.piece_list(side, piece, i);
- b = (pos.*mem_fn)(from) & target;
- while (b)
- {
- to = pop_1st_bit(&b);
- mlist[n++].move = make_move(from, to);
- }
+ Square from = pop_1st_bit(&b);
+ Bitboard bb = pos.piece_attacks<Piece>(from) & checkSqs;
+ SERIALIZE_MOVES(bb);
}
- return n;
+ return mlist;
}
+ template<Color Us, Rank TRANK_8, Bitboard TRank3BB, SquareDelta TDELTA_N>
+ MoveStack* do_generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned,
+ Bitboard blockSquares, MoveStack* mlist) {
+ Square to;
- int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us) {
-
- int n = 0;
+ // Find non-pinned pawns
+ Bitboard b1 = pos.pawns(Us) & not_pinned;
- if (pos.can_castle(us))
+ // Single pawn pushes. We don't have to AND with empty squares here,
+ // because the blocking squares will always be empty.
+ Bitboard b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & blockSquares;
+ while (b2)
{
- Color them = opposite_color(us);
- Square ksq = pos.king_square(us);
+ to = pop_1st_bit(&b2);
- assert(pos.piece_on(ksq) == king_of_color(us));
+ assert(pos.piece_on(to) == EMPTY);
- if (pos.can_castle_kingside(us))
+ if (square_rank(to) == TRANK_8)
{
- 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_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);
+ }
- assert(pos.piece_on(rsq) == rook_of_color(us));
+ // Double pawn pushes
+ b2 = (Us == WHITE ? b1 << 8 : b1 >> 8) & pos.empty_squares() & TRank3BB;
+ b2 = (Us == WHITE ? b2 << 8 : b2 >> 8) & blockSquares;;
+ while (b2)
+ {
+ to = pop_1st_bit(&b2);
- 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;
+ assert(pos.piece_on(to) == EMPTY);
+ assert(Us != WHITE || square_rank(to) == RANK_4);
+ assert(Us != BLACK || square_rank(to) == RANK_5);
- for (s = Min(rsq, f1); s <= Max(rsq, f1); s++)
- if (s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
+ (*mlist++).move = make_move(to - TDELTA_N - TDELTA_N, to);
+ }
+ return mlist;
+ }
- if (!illegal)
- mlist[n++].move = make_castle_move(ksq, rsq);
- }
+ template<CastlingSide Side>
+ MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) {
- 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 s;
- bool illegal = false;
+ Color us = pos.side_to_move();
- assert(pos.piece_on(rsq) == rook_of_color(us));
+ 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) == king_of_color(us));
+
+ 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;
- 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;
+ assert(pos.piece_on(rsq) == rook_of_color(us));
- for (s = Min(rsq, d1); s <= Max(rsq, d1); s++)
- if (s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
+ // 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;
- if ( square_file(rsq) == FILE_B
+ 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)) == 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);
- }
+ (*mlist++).move = make_castle_move(ksq, rsq);
}
- return n;
+ return mlist;
}
- int generate_piece_checks(PieceType pce, const Position& pos, Bitboard target,
- Bitboard dc, Square ksq, MoveStack* mlist) {
+ bool castling_is_check(const Position& pos, CastlingSide side) {
- const Piece_attacks_fn mem_fn = piece_attacks_fn[pce];
- int n = 0;
+ // 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();
- // Discovered checks
- Bitboard b = target & dc;
- while (b)
- {
- Square from = pop_1st_bit(&b);
- Bitboard bb = (pos.*mem_fn)(from) & pos.empty_squares();
- while (bb)
- {
- Square to = pop_1st_bit(&bb);
- mlist[n++].move = make_move(from, to);
- }
- }
-
- // Direct checks
- b = target & ~dc;
- Bitboard checkSqs = (pos.*mem_fn)(ksq) & pos.empty_squares();
- while (b)
- {
- Square from = pop_1st_bit(&b);
- Bitboard bb = (pos.*mem_fn)(from) & checkSqs;
- while (bb)
- {
- Square to = pop_1st_bit(&bb);
- mlist[n++].move = make_move(from, to);
- }
- }
- 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