+ template<CastlingSide Side>
+ MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) {
+
+ const CastleRight CR[] = { Side ? WHITE_OOO : WHITE_OO,
+ Side ? BLACK_OOO : BLACK_OO };
+
+ if (!pos.can_castle(CR[us]))
+ return mlist;
+
+ // 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 rfrom = pos.castle_rook_square(CR[us]);
+ Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1);
+ Bitboard enemies = pos.pieces(flip(us));
+
+ assert(!pos.in_check());
+ assert(pos.piece_on(kfrom) == make_piece(us, KING));
+ assert(pos.piece_on(rfrom) == make_piece(us, ROOK));
+
+ // Unimpeded rule: All the squares between the king's initial and final squares
+ // (including the final square), and all the squares between the rook's initial
+ // and final squares (including the final square), must be vacant except for
+ // the king and castling rook.
+ for (Square s = std::min(rfrom, rto), e = std::max(rfrom, rto); s <= e; s++)
+ if (s != kfrom && s != rfrom && !pos.square_is_empty(s))
+ return mlist;
+
+ for (Square s = std::min(kfrom, kto), e = std::max(kfrom, kto); s <= e; s++)
+ if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s))
+ ||(pos.attackers_to(s) & enemies))
+ return 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())
+ {
+ Bitboard occ = pos.occupied_squares();
+ clear_bit(&occ, rfrom);
+ if (pos.attackers_to(kto, occ) & enemies)
+ return mlist;
+ }
+
+ (*mlist++).move = make_castle(kfrom, rfrom);
+
+ return mlist;
+ }
+
+
+ template<Square Delta>
+ inline Bitboard move_pawns(Bitboard p) {
+
+ return Delta == DELTA_N ? p << 8 : Delta == DELTA_S ? p >> 8 :
+ Delta == DELTA_NE ? p << 9 : Delta == DELTA_SE ? p >> 7 :
+ Delta == DELTA_NW ? p << 7 : Delta == DELTA_SW ? p >> 9 : p;
+ }
+
+
+ template<Square Delta>
+ inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) {
+
+ const Bitboard EdgeFileBB = ( Delta == DELTA_NE
+ || Delta == DELTA_SE ? FileABB : FileHBB);
+ Bitboard b;
+ Square to;
+
+ b = move_pawns<Delta>(pawns) & target & ~EdgeFileBB;
+ SERIALIZE_MOVES_D(b, -Delta);
+ return mlist;
+ }
+
+
+ template<MoveType Type, Square Delta>
+ inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) {
+
+ const Bitboard EdgeFileBB = ( Delta == DELTA_NE
+ || Delta == DELTA_SE ? FileABB : FileHBB);
+ Bitboard b;
+ Square to;
+
+ b = move_pawns<Delta>(pawnsOn7) & target;
+
+ if (Delta != DELTA_N && Delta != DELTA_S)
+ b &= ~EdgeFileBB;
+
+ while (b)
+ {
+ to = pop_1st_bit(&b);
+
+ if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ (*mlist++).move = make_promotion(to - Delta, to, QUEEN);
+
+ if (Type == MV_NON_CAPTURE || 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 under promotion is the only one that can give a check not
+ // already included in the queen-promotion.
+ if (Type == MV_CHECK)
+ {
+ Square ksq = pos.king_square(Delta > 0 ? BLACK : WHITE);
+ if (bit_is_set(pos.attacks_from<KNIGHT>(to), ksq))
+ (*mlist++).move = make_promotion(to - Delta, to, KNIGHT);
+ }
+ else
+ (void)pos; // Silence a warning under MSVC
+ }
+ return mlist;
+ }
+
+
+ template<Color Us, MoveType Type>
+ MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq) {
+
+ // Calculate 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 TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);
+ const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ const Square UP = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Square RIGHT_UP = (Us == WHITE ? DELTA_NE : DELTA_SW);
+ const Square LEFT_UP = (Us == WHITE ? DELTA_NW : DELTA_SE);
+
+ Square to;
+ Bitboard b1, b2, dc1, dc2, pawnPushes, emptySquares;
+ Bitboard pawns = pos.pieces(PAWN, Us);
+ Bitboard pawnsOn7 = pawns & TRank7BB;
+ Bitboard enemyPieces = (Type == MV_CAPTURE ? target : pos.pieces(Them));
+
+ // Pre-calculate pawn pushes before changing emptySquares definition
+ if (Type != MV_CAPTURE)
+ {
+ emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares());
+ pawnPushes = move_pawns<UP>(pawns & ~TRank7BB) & emptySquares;
+ }
+
+ if (Type == MV_EVASION)
+ {
+ emptySquares &= target; // Only blocking squares
+ enemyPieces &= target; // Capture only the checker piece
+ }
+
+ // Promotions and underpromotions
+ if (pawnsOn7)
+ {
+ if (Type == MV_CAPTURE)
+ emptySquares = pos.empty_squares();
+
+ pawns &= ~TRank7BB;
+ mlist = generate_promotions<Type, RIGHT_UP>(pos, mlist, pawnsOn7, enemyPieces);
+ mlist = generate_promotions<Type, LEFT_UP>(pos, mlist, pawnsOn7, enemyPieces);
+ mlist = generate_promotions<Type, UP>(pos, mlist, pawnsOn7, emptySquares);
+ }
+
+ // Standard captures
+ if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ {
+ mlist = generate_pawn_captures<RIGHT_UP>(mlist, pawns, enemyPieces);
+ mlist = generate_pawn_captures<LEFT_UP>(mlist, pawns, enemyPieces);
+ }
+
+ // Single and double pawn pushes
+ if (Type != MV_CAPTURE)
+ {
+ b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares);
+ b2 = move_pawns<UP>(pawnPushes & TRank3BB) & emptySquares;
+
+ if (Type == MV_CHECK)
+ {
+ // Consider only pawn moves which give direct checks
+ b1 &= pos.attacks_from<PAWN>(ksq, Them);
+ b2 &= pos.attacks_from<PAWN>(ksq, Them);
+
+ // Add 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.
+ if (pawns & target) // For CHECK type target is dc bitboard
+ {
+ dc1 = move_pawns<UP>(pawns & target & ~file_bb(ksq)) & emptySquares;
+ dc2 = move_pawns<UP>(dc1 & TRank3BB) & emptySquares;
+
+ b1 |= dc1;
+ b2 |= dc2;
+ }
+ }
+ SERIALIZE_MOVES_D(b1, -UP);
+ SERIALIZE_MOVES_D(b2, -UP -UP);
+ }
+
+ // En passant captures
+ if ( (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION)
+ && pos.ep_square() != SQ_NONE)
+ {
+ assert(Us != WHITE || rank_of(pos.ep_square()) == RANK_6);
+ assert(Us != BLACK || rank_of(pos.ep_square()) == RANK_3);
+
+ // 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 && !bit_is_set(target, pos.ep_square() - UP))
+ return mlist;
+
+ b1 = pawns & pos.attacks_from<PAWN>(pos.ep_square(), Them);
+
+ assert(b1);
+
+ while (b1)
+ {
+ to = pop_1st_bit(&b1);
+ (*mlist++).move = make_enpassant(to, pos.ep_square());
+ }
+ }
+ return mlist;
+ }