X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=90d0135a4d0dbe246aa38daa54b94d28820d5ad4;hp=866f4d0705a880e80cf15803dae671809c1328d2;hb=ad1f28bc1c1c5426fb8ab246f5d43ad57002b4d5;hpb=b36900ef44044e9ab96637c9da7a4d7ea5b055d9 diff --git a/src/movegen.cpp b/src/movegen.cpp index 866f4d07..90d0135a 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -17,15 +17,11 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include #include "bitcount.h" #include "movegen.h" +#include "position.h" // Simple macro to wrap a very common while loop, no facny, no flexibility, // hardcoded list name 'mlist' and from square 'from'. @@ -34,10 +30,6 @@ // Version used for pawns, where the 'from' square is given as a delta from the 'to' square #define SERIALIZE_MOVES_D(b, d) while (b) { to = pop_1st_bit(&b); (*mlist++).move = make_move(to + (d), to); } -//// -//// Local definitions -//// - namespace { enum CastlingSide { @@ -45,149 +37,187 @@ namespace { QUEEN_SIDE }; - enum MoveType { - CAPTURE, - NON_CAPTURE, - CHECK, - EVASION - }; + template + MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us); - // Helper templates - template - MoveStack* generate_castle_moves(const Position&, MoveStack*); - - template + template MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square); - // Template generate_piece_moves (captures and non-captures) with specializations and overloads - template - MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard); + template + inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) { - template<> - MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard); + assert(Pt != QUEEN); + assert(Pt != PAWN); - template - inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) { + Bitboard b = pos.attacks_from(from) & pos.empty_squares(); - assert(Piece == PAWN); - assert(Type == CAPTURE || Type == NON_CAPTURE || Type == EVASION); + if (Pt == KING) + b &= ~QueenPseudoAttacks[pos.king_square(opposite_color(pos.side_to_move()))]; - return (us == WHITE ? generate_pawn_moves(p, m, t, SQ_NONE) - : generate_pawn_moves(p, m, t, SQ_NONE)); + SERIALIZE_MOVES(b); + return mlist; } - // Templates for non-capture checks generation + template + inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us, + Bitboard dc, Square ksq) { + assert(Pt != KING); + assert(Pt != PAWN); - template - MoveStack* generate_discovered_checks(const Position&, MoveStack*, Square); + Bitboard checkSqs, b; + Square from; + const Square* pl = pos.piece_list(us, Pt); - template - MoveStack* generate_direct_checks(const Position&, MoveStack*, Color, Bitboard, Square); + if ((from = *pl++) == SQ_NONE) + return mlist; - template<> - inline MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { + checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); - return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq) - : generate_pawn_moves(p, m, dc, ksq)); - } -} + do + { + if ( (Pt == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) + || (Pt == ROOK && !(RookPseudoAttacks[from] & checkSqs)) + || (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) + continue; + if (dc && bit_is_set(dc, from)) + continue; -//// -//// Functions -//// + b = pos.attacks_from(from) & checkSqs; + SERIALIZE_MOVES(b); + } while ((from = *pl++) != SQ_NONE); -/// generate_captures() generates all pseudo-legal captures and queen -/// promotions. Returns a pointer to the end of the move list. + return mlist; + } -MoveStack* generate_captures(const Position& pos, MoveStack* mlist) { + template<> + FORCE_INLINE MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { - assert(pos.is_ok()); - assert(!pos.is_check()); + return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq) + : generate_pawn_moves(p, m, dc, ksq)); + } - Color us = pos.side_to_move(); - Bitboard target = pos.pieces_of_color(opposite_color(us)); + template + FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) { - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - return generate_piece_moves(pos, mlist, us, target); -} + assert(Pt == PAWN); + assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_EVASION); + return (us == WHITE ? generate_pawn_moves(p, m, t, SQ_NONE) + : generate_pawn_moves(p, m, t, SQ_NONE)); + } -/// generate_noncaptures() generates all pseudo-legal non-captures and -/// underpromotions. Returns a pointer to the end of the move list. + template + FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { -MoveStack* generate_noncaptures(const Position& pos, MoveStack* mlist) { + Bitboard b; + Square from; + const Square* pl = pos.piece_list(us, Pt); - assert(pos.is_ok()); - assert(!pos.is_check()); + if (*pl != SQ_NONE) + { + do { + from = *pl; + b = pos.attacks_from(from) & target; + SERIALIZE_MOVES(b); + } while (*++pl != SQ_NONE); + } + return mlist; + } - Color us = pos.side_to_move(); - Bitboard target = pos.empty_squares(); + template<> + FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { + + Bitboard b; + Square from = pos.king_square(us); + + b = pos.attacks_from(from) & target; + SERIALIZE_MOVES(b); + return mlist; + } - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_castle_moves(pos, mlist); - return generate_castle_moves(pos, mlist); } -/// generate_non_evasions() generates all pseudo-legal captures and +/// generate generates all pseudo-legal captures and queen +/// promotions. Returns a pointer to the end of the move list. +/// +/// generate generates all pseudo-legal non-captures and +/// underpromotions. Returns a pointer to the end of the move list. +/// +/// generate generates all pseudo-legal captures and /// non-captures. Returns a pointer to the end of the move list. -MoveStack* generate_non_evasions(const Position& pos, MoveStack* mlist) { +template +MoveStack* generate(const Position& pos, MoveStack* mlist) { - assert(pos.is_ok()); - assert(!pos.is_check()); + assert(!pos.in_check()); Color us = pos.side_to_move(); - Bitboard target = pos.pieces_of_color(opposite_color(us)); + Bitboard target; - mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_piece_moves(pos, mlist, us, pos.empty_squares()); + if (Type == MV_CAPTURE || Type == MV_NON_EVASION) + target = pos.pieces(opposite_color(us)); + else if (Type == MV_NON_CAPTURE) + target = pos.empty_squares(); + else + assert(false); - target |= pos.empty_squares(); + if (Type == MV_NON_EVASION) + { + mlist = generate_piece_moves(pos, mlist, us, target); + mlist = generate_piece_moves(pos, mlist, us, pos.empty_squares()); + target |= pos.empty_squares(); + } + else + mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); - mlist = generate_castle_moves(pos, mlist); - return generate_castle_moves(pos, mlist); + + if (Type != MV_CAPTURE && pos.can_castle(us)) + { + if (pos.can_castle(us == WHITE ? WHITE_OO : BLACK_OO)) + mlist = generate_castle_moves(pos, mlist, us); + + if (pos.can_castle(us == WHITE ? WHITE_OOO : BLACK_OOO)) + mlist = generate_castle_moves(pos, mlist, us); + } + + return mlist; } +// Explicit template instantiations +template MoveStack* generate(const Position& pos, MoveStack* mlist); +template MoveStack* generate(const Position& pos, MoveStack* mlist); +template MoveStack* generate(const Position& pos, MoveStack* mlist); + /// generate_non_capture_checks() 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(const Position& pos, MoveStack* mlist) { -MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist) { - - assert(pos.is_ok()); - assert(!pos.is_check()); + assert(!pos.in_check()); Bitboard b, dc; Square from; Color us = pos.side_to_move(); Square ksq = pos.king_square(opposite_color(us)); - assert(pos.piece_on(ksq) == piece_of_color_and_type(opposite_color(us), KING)); + assert(pos.piece_on(ksq) == make_piece(opposite_color(us), KING)); // Discovered non-capture checks - b = dc = pos.discovered_check_candidates(us); + b = dc = pos.discovered_check_candidates(); while (b) { from = pop_1st_bit(&b); - switch (pos.type_of_piece_on(from)) + switch (piece_type(pos.piece_on(from))) { case PAWN: /* Will be generated togheter with pawns direct checks */ break; case KNIGHT: mlist = generate_discovered_checks(pos, mlist, from); break; @@ -209,11 +239,10 @@ MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist) { /// generate_evasions() 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(const Position& pos, MoveStack* mlist) { -MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { - - assert(pos.is_ok()); - assert(pos.is_check()); + assert(pos.in_check()); Bitboard b, target; Square from, checksq; @@ -223,7 +252,7 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { Bitboard checkers = pos.checkers(); Bitboard sliderAttacks = EmptyBoardBB; - assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING)); + assert(pos.piece_on(ksq) == make_piece(us, KING)); assert(checkers); // Find squares attacked by slider checkers, we will remove @@ -235,26 +264,31 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { checkersCnt++; checksq = pop_1st_bit(&b); - assert(pos.color_of_piece_on(checksq) == opposite_color(us)); + assert(piece_color(pos.piece_on(checksq)) == opposite_color(us)); - switch (pos.type_of_piece_on(checksq)) + switch (piece_type(pos.piece_on(checksq))) { case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break; case ROOK: sliderAttacks |= RookPseudoAttacks[checksq]; break; case QUEEN: - // In case of a queen remove also squares attacked in the other direction to - // avoid possible illegal moves when queen and king are on adjacent squares. - if (direction_is_straight(checksq, ksq)) - sliderAttacks |= RookPseudoAttacks[checksq] | pos.attacks_from(checksq); + // If queen and king are far 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) || (RookPseudoAttacks[checksq] & (1ULL << ksq))) + sliderAttacks |= QueenPseudoAttacks[checksq]; + + // Otherwise, if king and queen are adjacent and on a diagonal line, 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 |= BishopPseudoAttacks[checksq] | pos.attacks_from(checksq); + default: break; } } while (b); // Generate evasions for king, capture and non capture moves - b = pos.attacks_from(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks; + b = pos.attacks_from(ksq) & ~pos.pieces(us) & ~sliderAttacks; from = ksq; SERIALIZE_MOVES(b); @@ -266,7 +300,7 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { // checker piece is possible. target = squares_between(checksq, ksq) | checkers; - mlist = generate_piece_moves(pos, mlist, us, target); + mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); mlist = generate_piece_moves(pos, mlist, us, target); @@ -274,177 +308,31 @@ MoveStack* generate_evasions(const Position& pos, MoveStack* mlist) { } -/// generate_moves() computes a complete list of legal or pseudo-legal moves in -/// the current position. This function is not very fast, and should be used -/// only in non time-critical paths. - -MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLegal) { +/// generate computes a complete list of legal moves in the current position - assert(pos.is_ok()); +template<> +MoveStack* generate(const Position& pos, MoveStack* mlist) { MoveStack *last, *cur = mlist; - Bitboard pinned = pos.pinned_pieces(pos.side_to_move()); + Bitboard pinned = pos.pinned_pieces(); - // Generate pseudo-legal moves - last = pos.is_check() ? generate_evasions(pos, mlist) - : generate_non_evasions(pos, mlist); - if (pseudoLegal) - return last; + last = pos.in_check() ? generate(pos, mlist) + : generate(pos, mlist); // Remove illegal moves from the list while (cur != last) - if (pos.pl_move_is_legal(cur->move, pinned)) - cur++; - else + if (!pos.pl_move_is_legal(cur->move, pinned)) cur->move = (--last)->move; + else + cur++; return last; } -/// move_is_legal() takes a position and a (not necessarily pseudo-legal) -/// move and tests whether the move is legal. This version is not very fast -/// and should be used only in non time-critical paths. - -bool move_is_legal(const Position& pos, const Move m) { - - MoveStack mlist[MOVES_MAX]; - MoveStack *cur, *last = generate_moves(pos, mlist, true); - - for (cur = mlist; cur != last; cur++) - if (cur->move == m) - return pos.pl_move_is_legal(m, pos.pinned_pieces(pos.side_to_move())); - - return false; -} - - -/// Fast version of move_is_legal() that takes a position a move and a -/// bitboard of pinned pieces as input, and tests whether the move is legal. - -bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { - - assert(pos.is_ok()); - 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); - Square from = move_from(m); - Square to = move_to(m); - Piece pc = pos.piece_on(from); - - // Use a slower but simpler function for uncommon cases - if (move_is_special(m)) - return move_is_legal(pos, m); - - // 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 false; - - // The destination square cannot be occupied by a friendly piece - if (pos.color_of_piece_on(to) == us) - return false; - - // Handle the special case of a pawn move - if (type_of_piece(pc) == PAWN) - { - // Move direction must be compatible with pawn color - int direction = to - from; - if ((us == WHITE) != (direction > 0)) - return false; - - // We have already handled promotion moves, so destination - // cannot be on the 8/1th rank. - if (square_rank(to) == RANK_8 || square_rank(to) == RANK_1) - return false; - - // Proceed according to the square delta between the origin and - // destination squares. - switch (direction) - { - 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 false; - break; - - case DELTA_N: - case DELTA_S: - // Pawn push. The destination square must be empty. - if (!pos.square_is_empty(to)) - return false; - 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 false; - 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 false; - break; - - default: - return false; - } - } - else if (!bit_is_set(pos.attacks_from(pc, from), to)) - return false; - - // The move is pseudo-legal, check if it is also legal - return pos.is_check() ? pos.pl_move_is_evasion(m, pinned) : pos.pl_move_is_legal(m, pinned); -} - - namespace { - template - MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { - - Bitboard b; - Square from; - const Square* ptr = pos.piece_list_begin(us, Piece); - - if (*ptr != SQ_NONE) - { - do { - from = *ptr; - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - } while (*++ptr != SQ_NONE); - } - return mlist; - } - - template<> - MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { - - Bitboard b; - Square from = pos.king_square(us); - - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - return mlist; - } - - template + template inline Bitboard move_pawns(Bitboard p) { return Delta == DELTA_N ? p << 8 : Delta == DELTA_S ? p >> 8 : @@ -452,149 +340,138 @@ namespace { Delta == DELTA_NW ? p << 7 : Delta == DELTA_SW ? p >> 9 : p; } - template + template inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) { - // Calculate our parametrized parameters at compile time - const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB); const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); - Bitboard b1, b2; + Bitboard b; Square to; // Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black) - b1 = move_pawns(pawns) & ~TFileABB & target; + b = move_pawns(pawns) & target & ~TFileABB; + SERIALIZE_MOVES_D(b, -Delta); + return mlist; + } - // Capturing promotions and under-promotions - if (b1 & TRank8BB) - { - b2 = b1 & TRank8BB; - b1 &= ~TRank8BB; - while (b2) - { - to = pop_1st_bit(&b2); + template + inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) { - if (Type == CAPTURE || Type == EVASION) - (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN); + const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); - if (Type == NON_CAPTURE || Type == EVASION) - { - (*mlist++).move = make_promotion_move(to - Delta, to, ROOK); - (*mlist++).move = make_promotion_move(to - Delta, to, BISHOP); - (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT); - } + Bitboard b; + Square to; - // This is the only possible under promotion that can give a check - // not already included in the queen-promotion. It is not sure that - // the promoted knight will give check, but it doesn't worth to verify. - if (Type == CHECK) - (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT); - } - } + // Promotions and under-promotions, both captures and non-captures + b = move_pawns(pawnsOn7) & target; - // Serialize standard captures - if (Type == CAPTURE || Type == EVASION) - SERIALIZE_MOVES_D(b1, -Delta); + if (Delta != DELTA_N && Delta != DELTA_S) + b &= ~TFileABB; + while (b) + { + to = pop_1st_bit(&b); + + if (Type == MV_CAPTURE || Type == MV_EVASION) + (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN); + + if (Type == MV_NON_CAPTURE || Type == MV_EVASION) + { + (*mlist++).move = make_promotion_move(to - Delta, to, ROOK); + (*mlist++).move = make_promotion_move(to - Delta, to, BISHOP); + (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT); + } + + // This is the only possible under promotion that can give a check + // not already included in the queen-promotion. + if ( Type == MV_CHECK + && bit_is_set(pos.attacks_from(to), pos.king_square(Delta > 0 ? BLACK : WHITE))) + (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT); + else (void)pos; // Silence a warning under MSVC + } return mlist; } template MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq) { - // Calculate our parametrized parameters at compile time - 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 SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S); - const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE); - const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW); + // 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, enemyPieces, emptySquares; + 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)); - // Standard captures and capturing promotions and underpromotions - if (Type == CAPTURE || Type == EVASION || (pawns & TRank7BB)) + // Pre-calculate pawn pushes before changing emptySquares definition + if (Type != MV_CAPTURE) { - enemyPieces = (Type == CAPTURE ? target : pos.pieces_of_color(opposite_color(Us))); - - if (Type == EVASION) - enemyPieces &= target; // Capture only the checker piece - - mlist = generate_pawn_captures(mlist, pawns, enemyPieces); - mlist = generate_pawn_captures(mlist, pawns, enemyPieces); + emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares()); + pawnPushes = move_pawns(pawns & ~TRank7BB) & emptySquares; } - // Non-capturing promotions and underpromotions - if (pawns & TRank7BB) + if (Type == MV_EVASION) { - b1 = move_pawns(pawns) & TRank8BB & pos.empty_squares(); - - if (Type == EVASION) - b1 &= target; // Only blocking promotion pushes - - while (b1) - { - to = pop_1st_bit(&b1); - - if (Type == CAPTURE || Type == EVASION) - (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN); + emptySquares &= target; // Only blocking squares + enemyPieces &= target; // Capture only the checker piece + } - if (Type == NON_CAPTURE || Type == EVASION) - { - (*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); - } + // Promotions and underpromotions + if (pawnsOn7) + { + if (Type == MV_CAPTURE) + emptySquares = pos.empty_squares(); - // This is the only possible under promotion that can give a check - // not already included in the queen-promotion. - if (Type == CHECK && bit_is_set(pos.attacks_from(to), pos.king_square(Them))) - (*mlist++).move = make_promotion_move(to - TDELTA_N, to, KNIGHT); - } + pawns &= ~TRank7BB; + mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces); + mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces); + mlist = generate_promotions(pos, mlist, pawnsOn7, emptySquares); } - // Standard pawn pushes and double pushes - if (Type != CAPTURE) + // Standard captures + if (Type == MV_CAPTURE || Type == MV_EVASION) { - emptySquares = (Type == NON_CAPTURE ? target : pos.empty_squares()); + mlist = generate_pawn_captures(mlist, pawns, enemyPieces); + mlist = generate_pawn_captures(mlist, pawns, enemyPieces); + } - // Single and double pawn pushes - b1 = move_pawns(pawns) & emptySquares & ~TRank8BB; - b2 = move_pawns(b1 & TRank3BB) & emptySquares; + // Single and double pawn pushes + if (Type != MV_CAPTURE) + { + b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares); + b2 = move_pawns(pawnPushes & TRank3BB) & emptySquares; - // Filter out unwanted pushes according to the move type - if (Type == EVASION) + if (Type == MV_CHECK) { - b1 &= target; - b2 &= target; - } - else if (Type == CHECK) - { - // Pawn moves which give direct cheks + // Consider only pawn moves which give direct checks b1 &= pos.attacks_from(ksq, Them); b2 &= pos.attacks_from(ksq, Them); - // 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. + // 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 { - Bitboard dc1 = move_pawns(pawns & target & ~file_bb(ksq)) & emptySquares & ~TRank8BB; - Bitboard dc2 = move_pawns(dc1 & TRank3BB) & emptySquares; + dc1 = move_pawns(pawns & target & ~file_bb(ksq)) & emptySquares; + dc2 = move_pawns(dc1 & TRank3BB) & emptySquares; b1 |= dc1; b2 |= dc2; } } - SERIALIZE_MOVES_D(b1, -TDELTA_N); - SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N); + SERIALIZE_MOVES_D(b1, -UP); + SERIALIZE_MOVES_D(b2, -UP -UP); } // En passant captures - if ((Type == CAPTURE || Type == EVASION) && pos.ep_square() != SQ_NONE) + if ((Type == MV_CAPTURE || Type == MV_EVASION) && pos.ep_square() != SQ_NONE) { assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6); assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3); @@ -602,7 +479,7 @@ namespace { // 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 == EVASION && !bit_is_set(target, pos.ep_square() - TDELTA_N)) + if (Type == MV_EVASION && !bit_is_set(target, pos.ep_square() - UP)) return mlist; b1 = pawns & pos.attacks_from(pos.ep_square(), Them); @@ -618,93 +495,50 @@ namespace { return mlist; } - template - MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) { + template + MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) { + + CastleRight f = CastleRight((Side == KING_SIDE ? WHITE_OO : WHITE_OOO) << us); + Color them = opposite_color(us); + + // After castling, the rook and king's final positions are exactly the same + // in Chess960 as they would be in standard chess. + Square kfrom = pos.king_square(us); + Square rfrom = pos.castle_rook_square(f); + Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1); + Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1); + + 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 = Min(kfrom, kto); s <= Max(kfrom, kto); s++) + if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s)) + ||(pos.attackers_to(s) & pos.pieces(them))) + return mlist; - assert(Piece != QUEEN); + for (Square s = Min(rfrom, rto); s <= Max(rfrom, rto); s++) + if (s != kfrom && s != rfrom && !pos.square_is_empty(s)) + return mlist; - Bitboard b = pos.attacks_from(from) & pos.empty_squares(); - if (Piece == KING) + // 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()) { - Square ksq = pos.king_square(opposite_color(pos.side_to_move())); - b &= ~QueenPseudoAttacks[ksq]; + Bitboard occ = pos.occupied_squares(); + clear_bit(&occ, rfrom); + if (pos.attackers_to(kto, occ) & pos.pieces(them)) + return mlist; } - SERIALIZE_MOVES(b); - return mlist; - } - - template - MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us, - Bitboard dc, Square ksq) { - assert(Piece != KING); - - Bitboard checkSqs, b; - Square from; - const Square* ptr = pos.piece_list_begin(us, Piece); - - if ((from = *ptr++) == SQ_NONE) - return mlist; - checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); - - do - { - if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) - || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs)) - || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) - continue; - - if (dc && bit_is_set(dc, from)) - continue; - - b = pos.attacks_from(from) & checkSqs; - SERIALIZE_MOVES(b); - - } while ((from = *ptr++) != SQ_NONE); + (*mlist++).move = make_castle_move(kfrom, rfrom); return mlist; } - template - MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) { - - Color us = pos.side_to_move(); - - 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) == piece_of_color_and_type(us, KING)); - - 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; - - assert(pos.piece_on(rsq) == piece_of_color_and_type(us, ROOK)); - - // 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.attackers_to(s) & pos.pieces_of_color(them))) - illegal = true; - - 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)) == piece_of_color_and_type(them, ROOK) - || pos.piece_on(relative_square(us, SQ_A1)) == piece_of_color_and_type(them, QUEEN))) - illegal = true; - - if (!illegal) - (*mlist++).move = make_castle_move(ksq, rsq); - } - return mlist; - } -} +} // namespace