- 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 TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S);
- const Square TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE);
- const Square TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW);
-
- 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_of_color(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<TDELTA_N>(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<Us, Type, TDELTA_NE>(pos, mlist, pawnsOn7, enemyPieces);
- mlist = generate_promotions<Us, Type, TDELTA_NW>(pos, mlist, pawnsOn7, enemyPieces);
- mlist = generate_promotions<Us, Type, TDELTA_N >(pos, mlist, pawnsOn7, emptySquares);
- }
-
- // Standard captures
- if (Type == MV_CAPTURE || Type == MV_EVASION)
- {
- mlist = generate_pawn_captures<Type, TDELTA_NE>(mlist, pawns, enemyPieces);
- mlist = generate_pawn_captures<Type, TDELTA_NW>(mlist, pawns, enemyPieces);
- }
-
- // Single and double pawn pushes
- if (Type != MV_CAPTURE)
- {
- b1 = pawnPushes & emptySquares;
- b2 = move_pawns<TDELTA_N>(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<TDELTA_N>(pawns & target & ~file_bb(ksq)) & emptySquares;
- dc2 = move_pawns<TDELTA_N>(dc1 & TRank3BB) & emptySquares;
-
- b1 |= dc1;
- b2 |= dc2;
- }
- }
- SERIALIZE_MOVES_D(b1, -TDELTA_N);
- SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N);
- }