/*
- 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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
- 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/>.
*/
-
-////
-//// Includes
-////
-
+#include <algorithm>
#include <cassert>
#include "movegen.h"
+#include "position.h"
+/// Simple macro to wrap a very common while loop, no facny, no flexibility,
+/// hardcoded names 'mlist' and 'from'.
+#define SERIALIZE(b) while (b) (*mlist++).move = make_move(from, pop_1st_bit(&b))
-////
-//// Local definitions
-////
-
+/// Version used for pawns, where the 'from' square is given as a delta from the 'to' square
+#define SERIALIZE_PAWNS(b, d) while (b) { Square to = pop_1st_bit(&b); \
+ (*mlist++).move = make_move(to - (d), to); }
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);
-
- inline Bitboard next_row_white(Bitboard b) { return b << 8; }
- inline Bitboard next_row_black(Bitboard b) { return b >> 8; }
-
- struct PawnOffsets {
-
- Bitboard Rank3BB;
- Bitboard Rank8BB;
- SquareDelta DELTA_N;
- Color them;
- Bitboard (*next_row_fn)(Bitboard b);
- };
- const PawnOffsets WhitePawnOffsets = { Rank3BB, Rank8BB, DELTA_N, BLACK, &next_row_white };
- const PawnOffsets BlackPawnOffsets = { Rank6BB, Rank1BB, DELTA_S, WHITE, &next_row_black };
-
- int generate_pawn_checks(const PawnOffsets& ofs, const Position& pos, Bitboard dc,
- Square ksq, MoveStack* mlist);
-}
-
-
-////
-//// Functions
-////
-
-
-/// generate_captures generates() all pseudo-legal captures and queen
-/// promotions. The return value is the number of moves generated.
-
-int generate_captures(const Position& pos, MoveStack* mlist) {
-
- assert(pos.is_ok());
- assert(!pos.is_check());
-
- 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;
-}
-
-
-/// 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) {
-
- 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);
+ template<CastlingSide Side, bool OnlyChecks>
+ MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) {
- n += generate_castle_moves(pos, mlist+n, us);
- 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.
-
-int generate_checks(const Position& pos, MoveStack* mlist, Bitboard dc) {
-
- assert(pos.is_ok());
- assert(!pos.is_check());
-
- Color us = pos.side_to_move();
- Square ksq = pos.king_square(opposite_color(us));
- int n = 0;
+ CastleRight cr = CastleRight((Side == KING_SIDE ? WHITE_OO : WHITE_OOO) << us);
- assert(pos.piece_on(ksq) == king_of_color(opposite_color(us)));
+ if (pos.castle_impeded(us, Side) || !pos.can_castle(cr))
+ return mlist;
- dc = pos.discovered_check_candidates(us);
+ // After castling, the rook and king final positions are the same in Chess960
+ // as they would be in standard chess.
+ Square kfrom = pos.king_square(us);
+ Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ Square rfrom = pos.castle_rook_square(us, Side);
+ Bitboard enemies = pos.pieces(~us);
- // Pawn moves
- if (us == WHITE)
- n += generate_pawn_checks(WhitePawnOffsets, pos, dc, ksq, mlist);
- else
- n += generate_pawn_checks(BlackPawnOffsets, pos, dc, ksq, mlist);
+ assert(!pos.in_check());
- // Pieces moves
- Bitboard b = pos.knights(us);
- if (b)
- n += generate_piece_checks(KNIGHT, pos, b, dc, ksq, mlist);
+ for (Square s = std::min(kfrom, kto), e = std::max(kfrom, kto); s <= e; s++)
+ if ( s != kfrom // We are not in check
+ && (pos.attackers_to(s) & enemies))
+ return mlist;
- b = pos.bishops(us);
- if (b)
- n += generate_piece_checks(BISHOP, pos, b, dc, ksq, mlist);
+ // Because we generate only legal castling moves we need to verify that
+ // when moving the castling rook we do not discover some hidden checker.
+ // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
+ if ( pos.is_chess960()
+ && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
+ return mlist;
- b = pos.rooks(us);
- if (b)
- n += generate_piece_checks(ROOK, pos, b, dc, ksq, mlist);
+ (*mlist++).move = make_castle(kfrom, rfrom);
- b = pos.queens(us);
- if (b)
- n += generate_piece_checks(QUEEN, pos, b, dc, ksq, mlist);
+ if (OnlyChecks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos)))
+ mlist--;
- // King moves
- Square from = pos.king_square(us);
- if (bit_is_set(dc, from))
- {
- b = pos.king_attacks(from) & pos.empty_squares() & ~QueenPseudoAttacks[ksq];
- while (b)
- {
- Square to = pop_1st_bit(&b);
- mlist[n++].move = make_move(from, to);
- }
+ return mlist;
}
- // TODO: Castling moves!
-
- return n;
-}
-
-
-/// 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
-int generate_evasions(const Position &pos, MoveStack *mlist) {
+ template<Square Delta>
+ inline Bitboard move_pawns(Bitboard p) {
- 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);
-
- 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);
+ return Delta == DELTA_N ? p << 8
+ : Delta == DELTA_S ? p >> 8
+ : Delta == DELTA_NE ? (p & ~FileHBB) << 9
+ : Delta == DELTA_SE ? (p & ~FileHBB) >> 7
+ : Delta == DELTA_NW ? (p & ~FileABB) << 7
+ : Delta == DELTA_SW ? (p & ~FileABB) >> 9 : 0;
}
- // 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);
+ template<MoveType Type, Square Delta>
+ inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7, Bitboard target, Square ksq) {
- // 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);
- }
+ Bitboard b = move_pawns<Delta>(pawnsOn7) & target;
- // 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);
- }
+ while (b)
+ {
+ Square to = pop_1st_bit(&b);
- // 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);
- }
+ if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ (*mlist++).move = make_promotion(to - Delta, to, QUEEN);
- // 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);
+ if (Type == MV_QUIET || Type == MV_EVASION || Type == MV_NON_EVASION)
+ {
+ (*mlist++).move = make_promotion(to - Delta, to, ROOK);
+ (*mlist++).move = make_promotion(to - Delta, to, BISHOP);
+ (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
}
- }
- // 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);
- }
- }
+ // Knight-promotion is the only one that can give a direct check not
+ // already included in the queen-promotion.
+ if (Type == MV_QUIET_CHECK && (StepAttacksBB[W_KNIGHT][to] & ksq))
+ (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
+ else
+ (void)ksq; // Silence a warning under MSVC
}
- // 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);
- }
- }
+ return mlist;
}
- return n;
-}
+ template<Color Us, MoveType Type>
+ MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq = SQ_NONE) {
-/// 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
-/// very hard to write an efficient legal move generator, but for the moment
-/// we don't need it.
+ // Compute our parametrized parameters at compile time, named according to
+ // the point of view of white side.
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB);
+ const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
+ const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ const Square UP = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Square RIGHT = (Us == WHITE ? DELTA_NE : DELTA_SW);
+ const Square LEFT = (Us == WHITE ? DELTA_NW : DELTA_SE);
-int generate_legal_moves(const Position& pos, MoveStack* mlist) {
+ Bitboard b1, b2, dc1, dc2, emptySquares;
- assert(pos.is_ok());
+ Bitboard pawnsOn7 = pos.pieces(PAWN, Us) & TRank7BB;
+ Bitboard pawnsNotOn7 = pos.pieces(PAWN, Us) & ~TRank7BB;
- if (pos.is_check())
- return generate_evasions(pos, mlist);
+ Bitboard enemies = (Type == MV_EVASION ? pos.pieces(Them) & target:
+ Type == MV_CAPTURE ? target : pos.pieces(Them));
- // Generate pseudo-legal moves:
- int n = generate_captures(pos, mlist);
- n += generate_noncaptures(pos, mlist + n);
+ // Single and double pawn pushes, no promotions
+ if (Type != MV_CAPTURE)
+ {
+ emptySquares = (Type == MV_QUIET ? target : ~pos.pieces());
- Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
+ b1 = move_pawns<UP>(pawnsNotOn7) & emptySquares;
+ b2 = move_pawns<UP>(b1 & TRank3BB) & emptySquares;
- // Remove illegal moves from the list:
- for (int i = 0; i < n; i++)
- if (!pos.move_is_legal(mlist[i].move, pinned))
- mlist[i--].move = mlist[--n].move;
+ if (Type == MV_EVASION) // Consider only blocking squares
+ {
+ b1 &= target;
+ b2 &= target;
+ }
- return n;
-}
+ if (Type == MV_QUIET_CHECK)
+ {
+ b1 &= pos.attacks_from<PAWN>(ksq, Them);
+ b2 &= pos.attacks_from<PAWN>(ksq, Them);
+
+ // Add pawn pushes 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. Note that a possible discovery check
+ // promotion has been already generated among captures.
+ if (pawnsNotOn7 & target) // Target is dc bitboard
+ {
+ dc1 = move_pawns<UP>(pawnsNotOn7 & target) & emptySquares & ~file_bb(ksq);
+ dc2 = move_pawns<UP>(dc1 & TRank3BB) & emptySquares;
+
+ b1 |= dc1;
+ b2 |= dc2;
+ }
+ }
+ SERIALIZE_PAWNS(b1, UP);
+ SERIALIZE_PAWNS(b2, UP + UP);
+ }
-/// 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
-/// only be used when the side to move is not in check.
+ // Promotions and underpromotions
+ if (pawnsOn7 && (Type != MV_EVASION || (target & TRank8BB)))
+ {
+ if (Type == MV_CAPTURE)
+ emptySquares = ~pos.pieces();
-Move generate_move_if_legal(const Position &pos, Move m, Bitboard pinned) {
+ if (Type == MV_EVASION)
+ emptySquares &= target;
- assert(pos.is_ok());
- assert(!pos.is_check());
- assert(move_is_ok(m));
+ mlist = generate_promotions<Type, RIGHT>(mlist, pawnsOn7, enemies, ksq);
+ mlist = generate_promotions<Type, LEFT>(mlist, pawnsOn7, enemies, ksq);
+ mlist = generate_promotions<Type, UP>(mlist, pawnsOn7, emptySquares, ksq);
+ }
- Color us = pos.side_to_move();
- Color them = opposite_color(us);
- Square from = move_from(m);
- Piece pc = pos.piece_on(from);
+ // Standard and en-passant captures
+ if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ {
+ b1 = move_pawns<RIGHT>(pawnsNotOn7) & enemies;
+ b2 = move_pawns<LEFT >(pawnsNotOn7) & enemies;
- // 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;
+ SERIALIZE_PAWNS(b1, RIGHT);
+ SERIALIZE_PAWNS(b2, LEFT);
- Square to = move_to(m);
+ if (pos.ep_square() != SQ_NONE)
+ {
+ assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6));
- // 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 MOVE_NONE;
+ // An en passant capture can be an evasion only if the checking piece
+ // is the double pushed pawn and so is in the target. Otherwise this
+ // is a discovery check and we are forced to do otherwise.
+ if (Type == MV_EVASION && !(target & (pos.ep_square() - UP)))
+ return mlist;
- assert(pos.square_is_empty(to));
- assert(pos.piece_on(to - pawn_push(us)) == pawn_of_color(them));
+ b1 = pawnsNotOn7 & pos.attacks_from<PAWN>(pos.ep_square(), Them);
- // The move is pseudo-legal. If it is legal, return it.
- return (pos.move_is_legal(m) ? m : MOVE_NONE);
- }
+ assert(b1);
- // 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 MOVE_NONE;
-
- assert(from == pos.king_square(us));
- assert(to == pos.initial_kr_square(us));
- assert(pos.piece_on(to) == rook_of_color(us));
-
- 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 ? m : MOVE_NONE);
- }
+ while (b1)
+ (*mlist++).move = make_enpassant(pop_1st_bit(&b1), pos.ep_square());
+ }
+ }
- 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 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;
-
- return (!illegal ? m : MOVE_NONE);
+ return mlist;
}
- // Normal moves
-
- // 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.
- 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;
-
- // Proceed according to the square delta between the source and
- // destionation squares.
- switch (to - from)
- {
- 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 MOVE_NONE;
- break;
-
- case DELTA_N:
- case DELTA_S:
- // Pawn push. The destination square must be empty.
- if (!pos.square_is_empty(to))
- 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 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 MOVE_NONE;
- break;
+ template<PieceType Pt>
+ inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist,
+ Color us, const CheckInfo& ci) {
+ assert(Pt != KING && Pt != PAWN);
- default:
- return MOVE_NONE;
- }
- // The move is pseudo-legal. Return it if it is legal.
- return (pos.move_is_legal(m) ? m : MOVE_NONE);
- }
+ Bitboard b, target;
+ Square from;
+ const Square* pl = pos.piece_list(us, Pt);
- // 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);
-}
-
-
-namespace {
+ if (*pl != SQ_NONE)
+ {
+ target = ci.checkSq[Pt] & ~pos.pieces(); // Non capture checks only
- int generate_white_pawn_captures(const Position &pos, MoveStack *mlist) {
+ do {
+ from = *pl;
- Bitboard pawns = pos.pawns(WHITE);
- Bitboard enemyPieces = pos.pieces_of_color(BLACK);
- Square sq;
- int n = 0;
+ if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN)
+ && !(PseudoAttacks[Pt][from] & target))
+ continue;
- // Captures in the a1-h8 direction
- Bitboard b1 = (pawns << 9) & ~FileABB & enemyPieces;
+ if (ci.dcCandidates && (ci.dcCandidates & from))
+ continue;
- // Capturing promotions
- Bitboard b2 = b1 & Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_NE, sq, QUEEN);
+ b = pos.attacks_from<Pt>(from) & target;
+ SERIALIZE(b);
+ } while (*++pl != SQ_NONE);
}
- // Capturing non-promotions
- b2 = b1 & ~Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_NE, sq);
- }
+ return mlist;
+ }
- // Captures in the h1-a8 direction
- b1 = (pawns << 7) & ~FileHBB & enemyPieces;
- // Capturing promotions
- b2 = b1 & Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_NW, sq, QUEEN);
- }
+ template<PieceType Pt>
+ FORCE_INLINE MoveStack* generate_moves(const Position& pos, MoveStack* mlist,
+ Color us, Bitboard target) {
+ assert(Pt != KING && Pt != PAWN);
- // Capturing non-promotions
- b2 = b1 & ~Rank8BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_NW, sq);
- }
+ Bitboard b;
+ Square from;
+ const Square* pl = pos.piece_list(us, Pt);
- // 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);
- }
+ if (*pl != SQ_NONE)
+ do {
+ from = *pl;
+ b = pos.attacks_from<Pt>(from) & target;
+ SERIALIZE(b);
+ } while (*++pl != SQ_NONE);
- // 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());
- }
- }
- return n;
+ return mlist;
}
- int generate_black_pawn_captures(const Position &pos, MoveStack *mlist) {
+ template<>
+ FORCE_INLINE MoveStack* generate_moves<KING>(const Position& pos, MoveStack* mlist,
+ Color us, Bitboard target) {
+ Square from = pos.king_square(us);
+ Bitboard b = pos.attacks_from<KING>(from) & target;
+ SERIALIZE(b);
+ return mlist;
+ }
- Bitboard pawns = pos.pawns(BLACK);
- Bitboard enemyPieces = pos.pieces_of_color(WHITE);
- Square sq;
- int n = 0;
+} // namespace
- // Captures in the a8-h1 direction
- Bitboard b1 = (pawns >> 7) & ~FileABB & enemyPieces;
- // Capturing promotions
- Bitboard b2 = b1 & Rank1BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_SE, sq, QUEEN);
- }
+/// generate<MV_CAPTURE> generates all pseudo-legal captures and queen
+/// promotions. Returns a pointer to the end of the move list.
+///
+/// generate<MV_QUIET> generates all pseudo-legal non-captures and
+/// underpromotions. Returns a pointer to the end of the move list.
+///
+/// generate<MV_NON_EVASION> generates all pseudo-legal captures and
+/// non-captures. Returns a pointer to the end of the move list.
- // Capturing non-promotions
- b2 = b1 & ~Rank1BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_SE, sq);
- }
+template<MoveType Type>
+MoveStack* generate(const Position& pos, MoveStack* mlist) {
- // Captures in the h8-a1 direction
- b1 = (pawns >> 9) & ~FileHBB & enemyPieces;
+ assert(Type == MV_CAPTURE || Type == MV_QUIET || Type == MV_NON_EVASION);
+ assert(!pos.in_check());
- // Capturing promotions
- b2 = b1 & Rank1BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_promotion_move(sq - DELTA_SW, sq, QUEEN);
- }
+ Color us = pos.side_to_move();
+ Bitboard target;
- // Capturing Non-promotions
- b2 = b1 & ~Rank1BB;
- while (b2)
- {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_SW, sq);
- }
+ if (Type == MV_CAPTURE)
+ target = pos.pieces(~us);
- // 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);
- }
+ else if (Type == MV_QUIET)
+ target = ~pos.pieces();
- // 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());
- }
- }
- return n;
- }
+ else if (Type == MV_NON_EVASION)
+ target = ~pos.pieces(us);
+ mlist = (us == WHITE ? generate_pawn_moves<WHITE, Type>(pos, mlist, target)
+ : generate_pawn_moves<BLACK, Type>(pos, mlist, target));
- int generate_white_pawn_noncaptures(const Position &pos, MoveStack *mlist) {
+ mlist = generate_moves<KNIGHT>(pos, mlist, us, target);
+ mlist = generate_moves<BISHOP>(pos, mlist, us, target);
+ mlist = generate_moves<ROOK>(pos, mlist, us, target);
+ mlist = generate_moves<QUEEN>(pos, mlist, us, target);
+ mlist = generate_moves<KING>(pos, mlist, us, target);
- 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;
+ if (Type != MV_CAPTURE && pos.can_castle(us))
+ {
+ mlist = generate_castle<KING_SIDE, false>(pos, mlist, us);
+ mlist = generate_castle<QUEEN_SIDE, false>(pos, mlist, us);
+ }
- // 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);
- }
+ return 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);
- }
+// Explicit template instantiations
+template MoveStack* generate<MV_CAPTURE>(const Position& pos, MoveStack* mlist);
+template MoveStack* generate<MV_QUIET>(const Position& pos, MoveStack* mlist);
+template MoveStack* generate<MV_NON_EVASION>(const Position& pos, MoveStack* mlist);
- // 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);
- }
- b2 = b1 & ~Rank8BB;
- while(b2) {
- sq = pop_1st_bit(&b2);
- mlist[n++].move = make_move(sq - DELTA_N, sq);
- }
- // 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);
- }
+/// generate<MV_QUIET_CHECK> generates all pseudo-legal non-captures and knight
+/// underpromotions that give check. Returns a pointer to the end of the move list.
+template<>
+MoveStack* generate<MV_QUIET_CHECK>(const Position& pos, MoveStack* mlist) {
- return n;
- }
+ assert(!pos.in_check());
+ Color us = pos.side_to_move();
+ CheckInfo ci(pos);
+ Bitboard dc = ci.dcCandidates;
- 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);
- }
+ while (dc)
+ {
+ Square from = pop_1st_bit(&dc);
+ PieceType pt = type_of(pos.piece_on(from));
- // 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 (pt == PAWN)
+ continue; // Will be generated togheter with direct checks
- // 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);
- }
+ Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces();
- return n;
- }
+ if (pt == KING)
+ b &= ~PseudoAttacks[QUEEN][ci.ksq];
+ SERIALIZE(b);
+ }
- int generate_piece_moves(PieceType piece, const Position &pos, MoveStack *mlist,
- Color side, Bitboard target) {
+ mlist = (us == WHITE ? generate_pawn_moves<WHITE, MV_QUIET_CHECK>(pos, mlist, ci.dcCandidates, ci.ksq)
+ : generate_pawn_moves<BLACK, MV_QUIET_CHECK>(pos, mlist, ci.dcCandidates, ci.ksq));
- const Piece_attacks_fn mem_fn = piece_attacks_fn[piece];
- Square from, to;
- Bitboard b;
- int n = 0;
+ mlist = generate_direct_checks<KNIGHT>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<BISHOP>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<ROOK>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<QUEEN>(pos, mlist, us, ci);
- for (int i = 0; i < pos.piece_count(side, piece); i++)
- {
- 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);
- }
- }
- return n;
+ if (pos.can_castle(us))
+ {
+ mlist = generate_castle<KING_SIDE, true>(pos, mlist, us);
+ mlist = generate_castle<QUEEN_SIDE, true>(pos, mlist, us);
}
+ return mlist;
+}
- int generate_castle_moves(const Position &pos, MoveStack *mlist, Color us) {
- int n = 0;
+/// generate<MV_EVASION> generates all pseudo-legal check evasions when the side
+/// to move is in check. Returns a pointer to the end of the move list.
+template<>
+MoveStack* generate<MV_EVASION>(const Position& pos, MoveStack* mlist) {
- if (pos.can_castle(us))
- {
- Color them = opposite_color(us);
- Square ksq = pos.king_square(us);
+ assert(pos.in_check());
- assert(pos.piece_on(ksq) == king_of_color(us));
+ Bitboard b, target;
+ Square from, checksq;
+ int checkersCnt = 0;
+ Color us = pos.side_to_move();
+ Square ksq = pos.king_square(us);
+ Bitboard sliderAttacks = 0;
+ Bitboard checkers = pos.checkers();
- 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;
+ assert(checkers);
- assert(pos.piece_on(rsq) == rook_of_color(us));
+ // Find squares attacked by slider checkers, we will remove them from the king
+ // evasions so to skip known illegal moves avoiding useless legality check later.
+ b = checkers;
+ do
+ {
+ checkersCnt++;
+ checksq = pop_1st_bit(&b);
- 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(color_of(pos.piece_on(checksq)) == ~us);
- for (s = Min(rsq, f1); s <= Max(rsq, f1); s++)
- if (s != ksq && s != rsq && pos.square_is_occupied(s))
- illegal = true;
+ switch (type_of(pos.piece_on(checksq)))
+ {
+ case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break;
+ case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break;
+ case QUEEN:
+ // If queen and king are far or not on a diagonal line we can safely
+ // remove all the squares attacked in the other direction becuase are
+ // not reachable by the king anyway.
+ if (squares_between(ksq, checksq) || !(PseudoAttacks[BISHOP][checksq] & ksq))
+ sliderAttacks |= PseudoAttacks[QUEEN][checksq];
+
+ // Otherwise we need to use real rook attacks to check if king is safe
+ // to move in the other direction. For example: king in B2, queen in A1
+ // a knight in B1, and we can safely move to C1.
+ else
+ sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from<ROOK>(checksq);
- if (!illegal)
- mlist[n++].move = make_castle_move(ksq, rsq);
+ default:
+ break;
}
+ } while (b);
- 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;
-
- assert(pos.piece_on(rsq) == rook_of_color(us));
-
- 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))
- 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);
- }
- }
- return n;
- }
+ // Generate evasions for king, capture and non capture moves
+ b = pos.attacks_from<KING>(ksq) & ~pos.pieces(us) & ~sliderAttacks;
+ from = ksq;
+ SERIALIZE(b);
- int generate_piece_checks(PieceType pce, const Position& pos, Bitboard target,
- Bitboard dc, Square ksq, MoveStack* mlist) {
+ // Generate evasions for other pieces only if not under a double check
+ if (checkersCnt > 1)
+ return mlist;
- const Piece_attacks_fn mem_fn = piece_attacks_fn[pce];
- int n = 0;
+ // Blocking evasions or captures of the checking piece
+ target = squares_between(checksq, ksq) | checkers;
- // 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);
- }
- }
+ mlist = (us == WHITE ? generate_pawn_moves<WHITE, MV_EVASION>(pos, mlist, target)
+ : generate_pawn_moves<BLACK, MV_EVASION>(pos, mlist, target));
- // 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;
- }
+ mlist = generate_moves<KNIGHT>(pos, mlist, us, target);
+ mlist = generate_moves<BISHOP>(pos, mlist, us, target);
+ mlist = generate_moves<ROOK>(pos, mlist, us, target);
+ return generate_moves<QUEEN>(pos, mlist, us, target);
+}
- int generate_pawn_checks(const PawnOffsets& ofs, const Position& pos, Bitboard dc, Square ksq, MoveStack* mlist)
- {
- // 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
- Bitboard b1 = pos.pawns(pos.side_to_move()) & ~file_bb(ksq), b2, b3;
-
- // Discovered checks, single pawn pushes
- b2 = b3 = (ofs.next_row_fn)(b1 & dc) & ~ofs.Rank8BB & empty;
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - ofs.DELTA_N, to);
- }
- // Discovered checks, double pawn pushes
- b3 = (ofs.next_row_fn)(b2 & ofs.Rank3BB) & empty;
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - ofs.DELTA_N - ofs.DELTA_N, to);
- }
+/// generate<MV_LEGAL> generates all the legal moves in the given position
- // Direct checks. These are possible only for pawns on neighboring files
- // of the enemy king
+template<>
+MoveStack* generate<MV_LEGAL>(const Position& pos, MoveStack* mlist) {
- b1 &= (~dc & neighboring_files_bb(ksq)); // FIXME why ~dc ??
+ MoveStack *last, *cur = mlist;
+ Bitboard pinned = pos.pinned_pieces();
- // Direct checks, single pawn pushes
- b2 = (ofs.next_row_fn)(b1) & empty;
- b3 = b2 & pos.pawn_attacks(ofs.them, ksq);
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - ofs.DELTA_N, to);
- }
+ last = pos.in_check() ? generate<MV_EVASION>(pos, mlist)
+ : generate<MV_NON_EVASION>(pos, mlist);
+ while (cur != last)
+ if (!pos.pl_move_is_legal(cur->move, pinned))
+ cur->move = (--last)->move;
+ else
+ cur++;
- // Direct checks, double pawn pushes
- b3 = (ofs.next_row_fn)(b2 & ofs.Rank3BB) & empty & pos.pawn_attacks(ofs.them, ksq);
- while (b3)
- {
- Square to = pop_1st_bit(&b3);
- mlist[n++].move = make_move(to - ofs.DELTA_N - ofs.DELTA_N, to);
- }
- return n;
- }
+ return last;
}
projects / stockfish / blobdiff