/*
- 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/>.
*/
namespace {
struct PawnParams {
-
Bitboard Rank3BB, Rank8BB;
Rank RANK_8;
SquareDelta DELTA_N, DELTA_NE, DELTA_NW;
};
const PawnParams WhitePawnParams = { Rank3BB, Rank8BB, RANK_8, DELTA_N, DELTA_NE, DELTA_NW, WHITE, BLACK };
const PawnParams BlackPawnParams = { Rank6BB, Rank1BB, RANK_1, DELTA_S, DELTA_SE, DELTA_SW, BLACK, WHITE };
-
- int generate_castle_moves(const Position&, MoveStack*, Color);
+
+ int generate_castle_moves(const Position&, MoveStack*);
template<Color>
int generate_pawn_captures(const Position&, MoveStack*);
template<Color>
int generate_pawn_noncaptures(const Position&, MoveStack*);
-
+
template<Color>
- int generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*, int);
+ int generate_pawn_checks(const Position&, Bitboard, Square, MoveStack*);
template<Color>
- int generate_pawn_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*, int);
+ int generate_pawn_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*);
template<PieceType>
- int generate_piece_moves(const Position&, MoveStack*, Color, Bitboard);
+ int generate_piece_moves(const Position&, MoveStack*, Color us, Bitboard);
+ template<>
+ int generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target);
template<PieceType>
- int generate_piece_checks(const Position&, Bitboard, Bitboard, Square, MoveStack*, int);
+ int generate_piece_checks(const Position&, Bitboard, Bitboard, Square, MoveStack*);
+ int generate_piece_checks_king(const Position&, Square, Bitboard, Square, MoveStack*);
template<PieceType>
- int generate_piece_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*, int);
-
-
- /// Templates are defined here to avoid lookup issues with specializations
-
- template<PieceType Piece>
- int generate_piece_moves(const Position &pos, MoveStack *mlist,
- Color side, Bitboard target) {
- int n = 0;
- for (int i = 0; i < pos.piece_count(side, Piece); i++)
- {
- Square from = pos.piece_list(side, Piece, i);
- Bitboard b = pos.piece_attacks<Piece>(from) & target;
- while (b)
- {
- Square to = pop_1st_bit(&b);
- mlist[n++].move = make_move(from, to);
- }
- }
- return n;
- }
-
-
- template<PieceType Piece>
- int generate_piece_checks(const Position& pos, Bitboard target, Bitboard dc,
- Square ksq, MoveStack* mlist, int n) {
- // Discovered checks
- Bitboard b = target & dc;
- while (b)
- {
- Square from = pop_1st_bit(&b);
- Bitboard bb = pos.piece_attacks<Piece>(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.piece_attacks<Piece>(ksq) & pos.empty_squares();
- while (b)
- {
- Square from = pop_1st_bit(&b);
- Bitboard bb = pos.piece_attacks<Piece>(from) & checkSqs;
- while (bb)
- {
- Square to = pop_1st_bit(&bb);
- mlist[n++].move = make_move(from, to);
- }
- }
- return n;
- }
-
-
- template<> // Special case the King
- int generate_piece_checks<KING>(const Position& pos, Bitboard, Bitboard dc,
- Square ksq, MoveStack* mlist, int n) {
- if (bit_is_set(dc, ksq))
- {
- Bitboard bb = pos.piece_attacks<KING>(ksq)
- & pos.empty_squares()
- & ~QueenPseudoAttacks[ksq];
- while (bb)
- {
- Square to = pop_1st_bit(&bb);
- mlist[n++].move = make_move(ksq, to);
- }
- }
- return n;
- }
-
-
- template<PieceType Piece>
- int generate_piece_blocking_evasions(const Position& pos, Bitboard b,
- Bitboard blockSquares, MoveStack* mlist, int n) {
- while (b)
- {
- Square from = pop_1st_bit(&b);
- Bitboard bb = pos.piece_attacks<Piece>(from) & blockSquares;
- while (bb)
- {
- Square to = pop_1st_bit(&bb);
- mlist[n++].move = make_move(from, to);
- }
- }
- return n;
- }
+ int generate_piece_blocking_evasions(const Position&, Bitboard, Bitboard, MoveStack*);
}
}
-/// generate_noncaptures() generates all pseudo-legal non-captures and
+/// 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) {
n += generate_piece_moves<ROOK>(pos, mlist+n, us, target);
n += generate_piece_moves<QUEEN>(pos, mlist+n, us, target);
n += generate_piece_moves<KING>(pos, mlist+n, us, target);
-
- n += generate_castle_moves(pos, mlist+n, us);
+ n += generate_castle_moves(pos, mlist+n);
return n;
}
/// 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.
+/// number of generated moves.
int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
dc = pos.discovered_check_candidates(us);
// Pawn moves
- if (us == WHITE)
- n = generate_pawn_checks<WHITE>(pos, dc, ksq, mlist, 0);
+ if (us == WHITE)
+ n = generate_pawn_checks<WHITE>(pos, dc, ksq, mlist);
else
- n = generate_pawn_checks<BLACK>(pos, dc, ksq, mlist, 0);
+ n = generate_pawn_checks<BLACK>(pos, dc, ksq, mlist);
// Pieces moves
Bitboard b = pos.knights(us);
if (b)
- n = generate_piece_checks<KNIGHT>(pos, b, dc, ksq, mlist, n);
+ n += generate_piece_checks<KNIGHT>(pos, b, dc, ksq, mlist+n);
b = pos.bishops(us);
if (b)
- n = generate_piece_checks<BISHOP>(pos, b, dc, ksq, mlist, n);
+ n += generate_piece_checks<BISHOP>(pos, b, dc, ksq, mlist+n);
b = pos.rooks(us);
if (b)
- n = generate_piece_checks<ROOK>(pos, b, dc, ksq, mlist, n);
+ n += generate_piece_checks<ROOK>(pos, b, dc, ksq, mlist+n);
b = pos.queens(us);
if (b)
- n = generate_piece_checks<QUEEN>(pos, b, dc, ksq, mlist, n);
+ n += generate_piece_checks<QUEEN>(pos, b, dc, ksq, mlist+n);
// Hopefully we always have a king ;-)
- n = generate_piece_checks<KING>(pos, b, dc, pos.king_square(us), mlist, n);
+ n += generate_piece_checks_king(pos, pos.king_square(us), dc, ksq, mlist+n);
// TODO: Castling moves!
-
+
return n;
}
int n = 0;
assert(pos.piece_on(ksq) == king_of_color(us));
-
+
// Generate evasions for king
Bitboard b1 = pos.piece_attacks<KING>(ksq) & ~pos.pieces_of_color(us);
Bitboard b2 = pos.occupied_squares();
while (b1)
{
- Square to = pop_1st_bit(&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 (!( (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them))
- || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them))
- || (pos.piece_attacks<KNIGHT>(to) & pos.knights(them))
- || (pos.pawn_attacks(us, to) & pos.pawns(them))
- || (pos.piece_attacks<KING>(to) & pos.kings(them))))
+ if (!( (bishop_attacks_bb(to, b2) & pos.bishops_and_queens(them))
+ || (rook_attacks_bb(to, b2) & pos.rooks_and_queens(them))
+ || (pos.piece_attacks<KNIGHT>(to) & pos.knights(them))
+ || (pos.pawn_attacks(us, to) & pos.pawns(them))
+ || (pos.piece_attacks<KING>(to) & pos.kings(them))))
mlist[n++].move = make_move(ksq, to);
}
// Pawn moves. Because a blocking evasion can never be a capture, we
// only generate pawn pushes.
if (us == WHITE)
- n = generate_pawn_blocking_evasions<WHITE>(pos, not_pinned, blockSquares, mlist, n);
+ n += generate_pawn_blocking_evasions<WHITE>(pos, not_pinned, blockSquares, mlist+n);
else
- n = generate_pawn_blocking_evasions<BLACK>(pos, not_pinned, blockSquares, mlist, n);
+ n += generate_pawn_blocking_evasions<BLACK>(pos, not_pinned, blockSquares, mlist+n);
// Pieces moves
b1 = pos.knights(us) & not_pinned;
if (b1)
- n = generate_piece_blocking_evasions<KNIGHT>(pos, b1, blockSquares, mlist, n);
+ n += generate_piece_blocking_evasions<KNIGHT>(pos, b1, blockSquares, mlist+n);
b1 = pos.bishops(us) & not_pinned;
if (b1)
- n = generate_piece_blocking_evasions<BISHOP>(pos, b1, blockSquares, mlist, n);
+ n += generate_piece_blocking_evasions<BISHOP>(pos, b1, blockSquares, mlist+n);
b1 = pos.rooks(us) & not_pinned;
if (b1)
- n = generate_piece_blocking_evasions<ROOK>(pos, b1, blockSquares, mlist, n);
+ n += generate_piece_blocking_evasions<ROOK>(pos, b1, blockSquares, mlist+n);
b1 = pos.queens(us) & not_pinned;
if (b1)
- n = generate_piece_blocking_evasions<QUEEN>(pos, b1, blockSquares, mlist, n);
+ n += generate_piece_blocking_evasions<QUEEN>(pos, b1, blockSquares, mlist+n);
}
// Finally, the ugly special case of en passant captures. An en passant
b1 = pos.pawn_attacks(them, to) & pos.pawns(us);
assert(b1 != EmptyBoardBB);
-
+
b1 &= not_pinned;
while (b1)
{
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[n++].move = make_ep_move(from, to);
}
}
/// returned. If not, the function returns MOVE_NONE. 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) {
+Move generate_move_if_legal(const Position& pos, Move m, Bitboard pinned) {
assert(pos.is_ok());
assert(!pos.is_check());
// 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)
namespace {
+ template<PieceType Piece>
+ int generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+
+ Square from, to;
+ Bitboard b;
+ int n = 0;
+
+ for (int i = 0; i < pos.piece_count(us, Piece); i++)
+ {
+ from = pos.piece_list(us, Piece, i);
+ b = pos.piece_attacks<Piece>(from) & target;
+ while (b)
+ {
+ to = pop_1st_bit(&b);
+ mlist[n++].move = make_move(from, to);
+ }
+ }
+ return n;
+ }
+
+ template<>
+ int generate_piece_moves<KING>(const Position& pos, MoveStack* mlist, Color us, Bitboard target) {
+
+ Bitboard b;
+ Square to, from = pos.king_square(us);
+ int n = 0;
+
+ b = pos.piece_attacks<KING>(from) & target;
+ while (b)
+ {
+ to = pop_1st_bit(&b);
+ mlist[n++].move = make_move(from, to);
+ }
+ return n;
+ }
+
+ template<PieceType Piece>
+ int generate_piece_blocking_evasions(const Position& pos, Bitboard b,
+ Bitboard blockSquares, MoveStack* mlist) {
+ int n = 0;
+ while (b)
+ {
+ Square from = pop_1st_bit(&b);
+ Bitboard bb = pos.piece_attacks<Piece>(from) & blockSquares;
+ while (bb)
+ {
+ Square to = pop_1st_bit(&bb);
+ mlist[n++].move = make_move(from, to);
+ }
+ }
+ return n;
+ }
+
+
template<Color C>
int generate_pawn_captures(const Position& pos, MoveStack* mlist) {
template<Color C>
- int generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist, int n)
+ int generate_pawn_checks(const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist)
{
static const PawnParams PP = (C == WHITE ? WhitePawnParams : BlackPawnParams);
- // 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
+ // 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.
+ int n = 0;
Bitboard empty = pos.empty_squares();
// Find all friendly pawns not on the enemy king's file
return n;
}
+ template<PieceType Piece>
+ int generate_piece_checks(const Position& pos, Bitboard target, Bitboard dc,
+ Square ksq, MoveStack* mlist) {
+ // Discovered checks
+ int n = 0;
+ Bitboard b = target & dc;
+ while (b)
+ {
+ Square from = pop_1st_bit(&b);
+ Bitboard bb = pos.piece_attacks<Piece>(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.piece_attacks<Piece>(ksq) & pos.empty_squares();
+ while (b)
+ {
+ Square from = pop_1st_bit(&b);
+ Bitboard bb = pos.piece_attacks<Piece>(from) & checkSqs;
+ while (bb)
+ {
+ Square to = pop_1st_bit(&bb);
+ mlist[n++].move = make_move(from, to);
+ }
+ }
+ return n;
+ }
+
+ int generate_piece_checks_king(const Position& pos, Square from, Bitboard dc,
+ Square ksq, MoveStack* mlist) {
+ int n = 0;
+ if (bit_is_set(dc, from))
+ {
+ Bitboard b = pos.piece_attacks<KING>(from)
+ & pos.empty_squares()
+ & ~QueenPseudoAttacks[ksq];
+ while (b)
+ {
+ Square to = pop_1st_bit(&b);
+ mlist[n++].move = make_move(from, to);
+ }
+ }
+ return n;
+ }
+
+
template<Color C>
int generate_pawn_blocking_evasions(const Position& pos, Bitboard not_pinned,
- Bitboard blockSquares, MoveStack* mlist, int n) {
+ Bitboard blockSquares, MoveStack* mlist) {
static const PawnParams PP = (C == WHITE ? WhitePawnParams : BlackPawnParams);
// Find non-pinned pawns
+ int n = 0;
Bitboard b1 = pos.pawns(PP.us) & not_pinned;
// Single pawn pushes. We don't have to AND with empty squares here,
}
- int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us) {
+ int generate_castle_moves(const Position& pos, MoveStack* mlist) {
int n = 0;
+ Color us = pos.side_to_move();
if (pos.can_castle(us))
{
Color them = opposite_color(us);
- Square ksq = pos.king_square(us);
+ Square ksq = pos.king_square(us);
assert(pos.piece_on(ksq) == king_of_color(us));
Square c1 = relative_square(us, SQ_C1);
Square d1 = relative_square(us, SQ_D1);
Square s;
- bool illegal = false;
+ bool illegal = false;
assert(pos.piece_on(rsq) == rook_of_color(us));
&& ( 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);
}