X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=6f932cd05de6befd53b89737c5e0aadae1cdb516;hp=738b2acc6f1494e43ce651b7bc50de9b2926bfe0;hb=ee0afea1e57e4c39140c838b9f9f2d5c7c061e6b;hpb=02fd34a5e840f0dd7e6e810f4fcea5ddf82858a9 diff --git a/src/movegen.cpp b/src/movegen.cpp index 738b2acc..6f932cd0 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2009 Marco Costalba + Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -26,6 +26,7 @@ #include "bitcount.h" #include "movegen.h" +#include "types.h" // Simple macro to wrap a very common while loop, no facny, no flexibility, // hardcoded list name 'mlist' and from square 'from'. @@ -45,311 +46,306 @@ namespace { QUEEN_SIDE }; - enum MoveType { - CAPTURE, - NON_CAPTURE, - CHECK, - EVASION - }; - - // Functions - bool castling_is_check(const Position&, CastlingSide); - - // Helper templates template - MoveStack* generate_castle_moves(const Position&, MoveStack*); + MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us); template - MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard = EmptyBoardBB, - Square = SQ_NONE, Bitboard = EmptyBoardBB); + MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square); + + template + inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) { + + assert(Piece != QUEEN); + + Bitboard b = pos.attacks_from(from) & pos.empty_squares(); + if (Piece == KING) + { + Square ksq = pos.king_square(opposite_color(pos.side_to_move())); + b &= ~QueenPseudoAttacks[ksq]; + } + SERIALIZE_MOVES(b); + return mlist; + } + + template + inline 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); - // Template generate_piece_moves (captures and non-captures) with specializations and overloads - template - MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard); + } while ((from = *ptr++) != SQ_NONE); + + return mlist; + } template<> - MoveStack* generate_piece_moves(const Position&, MoveStack*, Color, Bitboard); + FORCE_INLINE MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { + + return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq) + : generate_pawn_moves(p, m, dc, ksq)); + } template - inline MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us) { + FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) { assert(Piece == PAWN); - assert(Type == CAPTURE || Type == NON_CAPTURE); + assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_EVASION); - return (us == WHITE ? generate_pawn_moves(p, m) - : generate_pawn_moves(p, m)); + return (us == WHITE ? generate_pawn_moves(p, m, t, SQ_NONE) + : generate_pawn_moves(p, m, t, SQ_NONE)); } - // Template generate_piece_checks with specializations - template - MoveStack* generate_piece_checks(const Position&, MoveStack*, Color, Bitboard, Square); + template + FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { - template<> - inline MoveStack* generate_piece_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { + Bitboard b; + Square from; + const Square* ptr = pos.piece_list_begin(us, Piece); - return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq) - : generate_pawn_moves(p, m, dc, ksq)); + if (*ptr != SQ_NONE) + { + do { + from = *ptr; + b = pos.attacks_from(from) & target; + SERIALIZE_MOVES(b); + } while (*++ptr != SQ_NONE); + } + return mlist; } - // Template generate_piece_evasions with specializations - template - MoveStack* generate_piece_evasions(const Position&, MoveStack*, Color, Bitboard, Bitboard); - template<> - inline MoveStack* generate_piece_evasions(const Position& p, MoveStack* m, - Color us, Bitboard t, Bitboard pnd) { + FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { + + Bitboard b; + Square from = pos.king_square(us); - return (us == WHITE ? generate_pawn_moves(p, m, pnd, SQ_NONE, t) - : generate_pawn_moves(p, m, pnd, SQ_NONE, t)); + b = pos.attacks_from(from) & target; + SERIALIZE_MOVES(b); + return mlist; } -} +} //// //// Functions //// -/// generate_captures() generates all pseudo-legal captures and queen +/// 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_captures(const Position& pos, MoveStack* mlist) { +template +MoveStack* generate(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)); - - 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); - return generate_piece_moves(pos, mlist, us, target); -} + Bitboard target; + if (Type == MV_CAPTURE || Type == MV_NON_EVASION) + target = pos.pieces_of_color(opposite_color(us)); + else if (Type == MV_NON_CAPTURE) + target = pos.empty_squares(); + else + assert(false); -/// generate_noncaptures() generates all pseudo-legal non-captures and -/// underpromotions. Returns a pointer to the end of the move list. - -MoveStack* 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(); + 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); 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) + { + if (pos.can_castle_kingside(us)) + mlist = generate_castle_moves(pos, mlist, us); + + if (pos.can_castle_queenside(us)) + mlist = generate_castle_moves(pos, mlist, us); + } + + return mlist; } +// Explicit template instantiation +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 -/// underpromotions that give check. Returns a pointer to the end of the move list. -MoveStack* generate_non_capture_checks(const Position& pos, MoveStack* mlist, Bitboard dc) { +/// 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) { assert(pos.is_ok()); assert(!pos.is_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)); - // Pieces moves - mlist = generate_piece_checks(pos, mlist, us, dc, ksq); - mlist = generate_piece_checks(pos, mlist, us, dc, ksq); - mlist = generate_piece_checks(pos, mlist, us, dc, ksq); - mlist = generate_piece_checks(pos, mlist, us, dc, ksq); - mlist = generate_piece_checks(pos, mlist, us, dc, ksq); - mlist = generate_piece_checks(pos, mlist, us, dc, ksq); - - // Castling moves that give check. Very rare but nice to have! - if ( pos.can_castle_queenside(us) - && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_D) - && castling_is_check(pos, QUEEN_SIDE)) - mlist = generate_castle_moves(pos, mlist); - - if ( pos.can_castle_kingside(us) - && (square_rank(ksq) == square_rank(pos.king_square(us)) || square_file(ksq) == FILE_F) - && castling_is_check(pos, KING_SIDE)) - mlist = generate_castle_moves(pos, mlist); + // Discovered non-capture checks + b = dc = pos.discovered_check_candidates(us); - return mlist; -} + while (b) + { + from = pop_1st_bit(&b); + switch (pos.type_of_piece_on(from)) + { + case PAWN: /* Will be generated togheter with pawns direct checks */ break; + case KNIGHT: mlist = generate_discovered_checks(pos, mlist, from); break; + case BISHOP: mlist = generate_discovered_checks(pos, mlist, from); break; + case ROOK: mlist = generate_discovered_checks(pos, mlist, from); break; + case KING: mlist = generate_discovered_checks(pos, mlist, from); break; + default: assert(false); break; + } + } + // Direct non-capture checks + mlist = generate_direct_checks(pos, mlist, us, dc, ksq); + mlist = generate_direct_checks(pos, mlist, us, dc, ksq); + mlist = generate_direct_checks(pos, mlist, us, dc, ksq); + mlist = generate_direct_checks(pos, mlist, us, dc, ksq); + return generate_direct_checks(pos, mlist, us, dc, ksq); +} -/// 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. Returns a pointer to the end of the move list. -MoveStack* generate_evasions(const Position& pos, MoveStack* mlist, Bitboard pinned) { +/// 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) { assert(pos.is_ok()); assert(pos.is_check()); - Square from, to; + Bitboard b, target; + Square from, checksq; + int checkersCnt = 0; Color us = pos.side_to_move(); - Color them = opposite_color(us); Square ksq = pos.king_square(us); - Bitboard sliderAttacks = EmptyBoardBB; Bitboard checkers = pos.checkers(); + Bitboard sliderAttacks = EmptyBoardBB; assert(pos.piece_on(ksq) == piece_of_color_and_type(us, KING)); - - // The bitboard of occupied pieces without our king - Bitboard b_noKing = pos.occupied_squares(); - clear_bit(&b_noKing, ksq); + assert(checkers); // Find squares attacked by slider checkers, we will remove - // them from the king evasions set so to avoid a couple - // of cycles in the slow king evasions legality check loop - // and to be able to use attackers_to(). - Bitboard b = checkers & pos.pieces(BISHOP, QUEEN); - while (b) + // them from the king evasions set so to early skip known + // illegal moves and avoid an useless legality check later. + b = checkers; + do { - from = pop_1st_bit(&b); - sliderAttacks |= bishop_attacks_bb(from, b_noKing); - } + checkersCnt++; + checksq = pop_1st_bit(&b); - b = checkers & pos.pieces(ROOK, QUEEN); - while (b) - { - from = pop_1st_bit(&b); - sliderAttacks |= rook_attacks_bb(from, b_noKing); - } - - // Generate evasions for king, capture and non capture moves - Bitboard enemy = pos.pieces_of_color(them); - Bitboard b1 = pos.attacks_from(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks; - while (b1) - { - // Note that we can use attackers_to() only because we have already - // removed from b1 the squares attacked by slider checkers. - to = pop_1st_bit(&b1); - if (!(pos.attackers_to(to) & enemy)) - (*mlist++).move = make_move(ksq, to); - } + assert(pos.color_of_piece_on(checksq) == opposite_color(us)); - // 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))) // Only one bit set? - { - Square checksq = first_1(checkers); - - assert(pos.color_of_piece_on(checksq) == them); - - // Generate captures of the checking piece - - // Pawn captures - b1 = pos.attacks_from(checksq, them) & pos.pieces(PAWN, us) & ~pinned; - while (b1) + switch (pos.type_of_piece_on(checksq)) { - from = pop_1st_bit(&b1); - if (relative_rank(us, checksq) == RANK_8) - { - (*mlist++).move = make_promotion_move(from, checksq, QUEEN); - (*mlist++).move = make_promotion_move(from, checksq, ROOK); - (*mlist++).move = make_promotion_move(from, checksq, BISHOP); - (*mlist++).move = make_promotion_move(from, checksq, KNIGHT); - } else - (*mlist++).move = make_move(from, 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 (RookPseudoAttacks[checksq] & (1ULL << ksq)) + sliderAttacks |= RookPseudoAttacks[checksq] | pos.attacks_from(checksq); + else + sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from(checksq); + default: + break; } + } while (b); - // Pieces captures - b1 = ( (pos.attacks_from(checksq) & pos.pieces(KNIGHT, us)) - | (pos.attacks_from(checksq) & pos.pieces(BISHOP, QUEEN, us)) - | (pos.attacks_from(checksq) & pos.pieces(ROOK, QUEEN, us)) ) & ~pinned; + // Generate evasions for king, capture and non capture moves + b = pos.attacks_from(ksq) & ~pos.pieces_of_color(us) & ~sliderAttacks; + from = ksq; + SERIALIZE_MOVES(b); - while (b1) - { - from = pop_1st_bit(&b1); - (*mlist++).move = make_move(from, checksq); - } + // Generate evasions for other pieces only if not double check + if (checkersCnt > 1) + return mlist; - // Blocking check evasions are possible only if the checking piece is a slider - if (sliderAttacks) - { - Bitboard blockSquares = squares_between(checksq, ksq); - - assert((pos.occupied_squares() & blockSquares) == EmptyBoardBB); - - if (blockSquares) - { - mlist = generate_piece_evasions(pos, mlist, us, blockSquares, pinned); - mlist = generate_piece_evasions(pos, mlist, us, blockSquares, pinned); - mlist = generate_piece_evasions(pos, mlist, us, blockSquares, pinned); - mlist = generate_piece_evasions(pos, mlist, us, blockSquares, pinned); - mlist = generate_piece_evasions(pos, mlist, us, blockSquares, pinned); - } - } + // Find squares where a blocking evasion or a capture of the + // checker piece is possible. + target = squares_between(checksq, ksq) | checkers; - // Finally, the 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.pieces(PAWN, them))) - { - to = pos.ep_square(); - b1 = pos.attacks_from(to, them) & pos.pieces(PAWN, us); - - // The checking pawn cannot be a discovered (bishop) check candidate - // otherwise we were in check also before last double push move. - assert(!bit_is_set(pos.discovered_check_candidates(them), checksq)); - assert(count_1s(b1) == 1 || count_1s(b1) == 2); - - b1 &= ~pinned; - while (b1) - { - from = pop_1st_bit(&b1); - // Move is always legal because checking pawn is not a discovered - // check candidate and our capturing pawn has been already tested - // against pinned pieces. - (*mlist++).move = make_ep_move(from, to); - } - } - } - 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); + return generate_piece_moves(pos, mlist, us, target); } -/// 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. +/// generate computes a complete list of legal +/// or pseudo-legal moves in the current position. +template<> +inline MoveStack* generate(const Position& pos, MoveStack* mlist) { -MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLegal) { + assert(pos.is_ok()); + + return pos.is_check() ? generate(pos, mlist) + : generate(pos, mlist); +} + +template<> +MoveStack* generate(const Position& pos, MoveStack* mlist) { assert(pos.is_ok()); + MoveStack *last, *cur = mlist; Bitboard pinned = pos.pinned_pieces(pos.side_to_move()); - if (pos.is_check()) - return generate_evasions(pos, mlist, pinned); - - // Generate pseudo-legal moves - MoveStack* last = generate_captures(pos, mlist); - last = generate_noncaptures(pos, last); - if (pseudoLegal) - return last; + last = generate(pos, mlist); // Remove illegal moves from the list - for (MoveStack* cur = mlist; cur != last; cur++) - if (!pos.pl_move_is_legal(cur->move, pinned)) - { + while (cur != last) + if (pos.pl_move_is_legal(cur->move, pinned)) + cur++; + else cur->move = (--last)->move; - cur--; - } + return last; } @@ -360,11 +356,12 @@ MoveStack* generate_moves(const Position& pos, MoveStack* mlist, bool pseudoLega bool move_is_legal(const Position& pos, const Move m) { - MoveStack mlist[256]; - MoveStack* last = generate_moves(pos, mlist, true); - for (MoveStack* cur = mlist; cur != last; cur++) + MoveStack mlist[MOVES_MAX]; + MoveStack *cur, *last = generate(pos, mlist); + + for (cur = mlist; cur != last; cur++) if (cur->move == m) - return pos.pl_move_is_legal(m); + return pos.pl_move_is_legal(m, pos.pinned_pieces(pos.side_to_move())); return false; } @@ -372,25 +369,22 @@ bool move_is_legal(const Position& pos, const Move m) { /// 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. -/// This version must only be used when the side to move is not in check. bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { assert(pos.is_ok()); - assert(!pos.is_check()); - assert(move_is_ok(m)); assert(pinned == pos.pinned_pieces(pos.side_to_move())); - // Use a slower but simpler function for uncommon cases - if (move_is_ep(m) || move_is_castle(m)) - return move_is_legal(pos, m); - 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) @@ -408,10 +402,9 @@ bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { if ((us == WHITE) != (direction > 0)) return false; - // A pawn move is a promotion iff the destination square is - // on the 8/1th rank. - if (( (square_rank(to) == RANK_8 && us == WHITE) - ||(square_rank(to) == RANK_1 && us != WHITE)) != bool(move_is_promotion(m))) + // 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 @@ -458,324 +451,216 @@ bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { default: return false; } - // The move is pseudo-legal, check if it is also legal - return pos.pl_move_is_legal(m, pinned); } + else if (!bit_is_set(pos.attacks_from(pc, from), to)) + return false; - // Luckly we can handle all the other pieces in one go - return ( bit_is_set(pos.attacks_from(pc, from), to) - && pos.pl_move_is_legal(m, pinned) - && !move_is_promotion(m)); + // 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) { - - Square from; - Bitboard b; + template + inline Bitboard move_pawns(Bitboard p) { - for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++) - { - from = pos.piece_list(us, Piece, i); - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - } - return mlist; + 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<> - MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { + template + inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) { - Bitboard b; - Square from = pos.king_square(us); + const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - return mlist; - } - - template - MoveStack* generate_piece_evasions(const Position& pos, MoveStack* mlist, - Color us, Bitboard target, Bitboard pinned) { - Square from; Bitboard b; + Square to; - for (int i = 0, e = pos.piece_count(us, Piece); i < e; i++) - { - from = pos.piece_list(us, Piece, i); - if (pinned && bit_is_set(pinned, from)) - continue; - - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - } + // Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black) + b = move_pawns(pawns) & target & ~TFileABB; + SERIALIZE_MOVES_D(b, -Delta); return mlist; } - template - inline Bitboard move_pawns(Bitboard p) { - - if (Direction == DELTA_N) - return Us == WHITE ? p << 8 : p >> 8; - else if (Direction == DELTA_NE) - return Us == WHITE ? p << 9 : p >> 7; - else if (Direction == DELTA_NW) - return Us == WHITE ? p << 7 : p >> 9; - else - return p; - } - - template - MoveStack* generate_pawn_diagonal_captures(MoveStack* mlist, Bitboard pawns, Bitboard enemyPieces, bool promotion) { + template + inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) { - // Calculate our parametrized parameters at compile time - const Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB); - const Bitboard TFileABB = (Diagonal == DELTA_NE ? FileABB : FileHBB); - const SquareDelta TDELTA_NE = (Us == WHITE ? DELTA_NE : DELTA_SE); - const SquareDelta TDELTA_NW = (Us == WHITE ? DELTA_NW : DELTA_SW); - const SquareDelta TTDELTA_NE = (Diagonal == DELTA_NE ? TDELTA_NE : TDELTA_NW); + const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); + Bitboard b; Square to; - // Captures in the a1-h8 (a8-h1 for black) diagonal or in the h1-a8 (h8-a1 for black) - Bitboard b1 = move_pawns(pawns) & ~TFileABB & enemyPieces; + // Promotions and under-promotions, both captures and non-captures + b = move_pawns(pawnsOn7) & target; + + if (Delta != DELTA_N && Delta != DELTA_S) + b &= ~TFileABB; - // Capturing promotions - if (promotion) + while (b) { - Bitboard b2 = b1 & TRank8BB; - b1 &= ~TRank8BB; - while (b2) + 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) { - to = pop_1st_bit(&b2); - (*mlist++).move = make_promotion_move(to - TTDELTA_NE, to, QUEEN); + (*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); } - } - // Capturing non-promotions - SERIALIZE_MOVES_D(b1, -TTDELTA_NE); + // 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(opposite_color(Us)))) + (*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 dcp, - Square ksq, Bitboard blockSquares) { - - // 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); + 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 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); - const SquareDelta TDELTA_N = (Us == WHITE ? DELTA_N : DELTA_S); - Bitboard b1, b2, dcPawns1, dcPawns2; Square to; - Bitboard pawns = (Type == EVASION ? pos.pieces(PAWN, Us) & ~dcp : pos.pieces(PAWN, Us)); - Bitboard emptySquares = pos.empty_squares(); - bool possiblePromotion = pawns & TRank7BB; + 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)); - if (Type == CAPTURE) + // Pre-calculate pawn pushes before changing emptySquares definition + if (Type != MV_CAPTURE) { - // Standard captures and capturing promotions in both directions - Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us)); - mlist = generate_pawn_diagonal_captures(mlist, pawns, enemyPieces, possiblePromotion); - mlist = generate_pawn_diagonal_captures(mlist, pawns, enemyPieces, possiblePromotion); + emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares()); + pawnPushes = move_pawns(pawns & ~TRank7BB) & emptySquares; } - if (possiblePromotion) + if (Type == MV_EVASION) { - // When generating checks consider under-promotion moves (both captures - // and non captures) only if can give a discovery check. Note that dcp - // is dc bitboard or pinned bitboard when Type == EVASION. - Bitboard pp = (Type == CHECK ? pawns & dcp : pawns); - - if (Type != EVASION && Type != CAPTURE) - { - Bitboard enemyPieces = pos.pieces_of_color(opposite_color(Us)); - - // Underpromotion captures in the a1-h8 (a8-h1 for black) direction - b1 = move_pawns(pp) & ~FileABB & enemyPieces & TRank8BB; - while (b1) - { - to = pop_1st_bit(&b1); - (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, ROOK); - (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, BISHOP); - (*mlist++).move = make_promotion_move(to - TDELTA_NE, to, KNIGHT); - } - - // Underpromotion captures in the h1-a8 (h8-a1 for black) direction - b1 = move_pawns(pp) & ~FileHBB & enemyPieces & TRank8BB; - while (b1) - { - to = pop_1st_bit(&b1); - (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, ROOK); - (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, BISHOP); - (*mlist++).move = make_promotion_move(to - TDELTA_NW, to, KNIGHT); - } - } - - // Underpromotion pawn pushes. Also queen promotions for evasions and captures. - b1 = move_pawns(pp) & TRank8BB; - b1 &= (Type == EVASION ? blockSquares : emptySquares); - - while (b1) - { - to = pop_1st_bit(&b1); - if (Type == EVASION || Type == CAPTURE) - (*mlist++).move = make_promotion_move(to - TDELTA_N, to, QUEEN); - - if (Type != CAPTURE) - { - (*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); - } - } + emptySquares &= target; // Only blocking squares + enemyPieces &= target; // Capture only the checker piece } - if (Type == CAPTURE) + // Promotions and underpromotions + if (pawnsOn7) { - // En passant captures - if (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); + if (Type == MV_CAPTURE) + emptySquares = pos.empty_squares(); - Bitboard b1 = pawns & pos.attacks_from(pos.ep_square(), Them); - assert(b1 != EmptyBoardBB); - - while (b1) - { - to = pop_1st_bit(&b1); - (*mlist++).move = make_ep_move(to, pos.ep_square()); - } - } - return mlist; + pawns &= ~TRank7BB; + mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces); + mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces); + mlist = generate_promotions(pos, mlist, pawnsOn7, emptySquares); } - dcPawns1 = dcPawns2 = EmptyBoardBB; - if (Type == CHECK && (pawns & dcp)) + // Standard captures + if (Type == MV_CAPTURE || Type == MV_EVASION) { - // 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. - dcPawns1 = move_pawns(pawns & dcp & ~file_bb(ksq)) & emptySquares & ~TRank8BB; - dcPawns2 = move_pawns(dcPawns1 & TRank3BB) & emptySquares; + mlist = generate_pawn_captures(mlist, pawns, enemyPieces); + mlist = generate_pawn_captures(mlist, pawns, enemyPieces); } - // Single pawn pushes - b1 = move_pawns(pawns) & emptySquares & ~TRank8BB; - b2 = (Type == CHECK ? (b1 & pos.attacks_from(ksq, Them)) | dcPawns1 : - (Type == EVASION ? b1 & blockSquares : b1)); - SERIALIZE_MOVES_D(b2, -TDELTA_N); - - // Double pawn pushes - b1 = move_pawns(b1 & TRank3BB) & emptySquares; - b2 = (Type == CHECK ? (b1 & pos.attacks_from(ksq, Them)) | dcPawns2 : - (Type == EVASION ? b1 & blockSquares : b1)); - SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N); - return mlist; - } - - template - MoveStack* generate_piece_checks(const Position& pos, MoveStack* mlist, Color us, - Bitboard dc, Square ksq) { - - Bitboard target = pos.pieces(Piece, us); + // Single and double pawn pushes + if (Type != MV_CAPTURE) + { + b1 = pawnPushes & emptySquares; + b2 = move_pawns(pawnPushes & TRank3BB) & emptySquares; - // Discovered non-capture checks - Bitboard b = target & dc; + if (Type == MV_CHECK) + { + // Consider only pawn moves which give direct checks + b1 &= pos.attacks_from(ksq, Them); + b2 &= pos.attacks_from(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(pawns & target & ~file_bb(ksq)) & emptySquares; + dc2 = move_pawns(dc1 & TRank3BB) & emptySquares; - assert(Piece != QUEEN || !b); + b1 |= dc1; + b2 |= dc2; + } + } + SERIALIZE_MOVES_D(b1, -TDELTA_N); + SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N); + } - while (b) + // En passant captures + if ((Type == MV_CAPTURE || Type == MV_EVASION) && pos.ep_square() != SQ_NONE) { - Square from = pop_1st_bit(&b); - Bitboard bb = pos.attacks_from(from) & pos.empty_squares(); - if (Piece == KING) - bb &= ~QueenPseudoAttacks[ksq]; + assert(Us != WHITE || square_rank(pos.ep_square()) == RANK_6); + assert(Us != BLACK || square_rank(pos.ep_square()) == RANK_3); - SERIALIZE_MOVES(bb); - } + // 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() - TDELTA_N)) + return mlist; - // Direct non-capture checks - b = target & ~dc; - Bitboard checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); - if (Piece == KING || !checkSqs) - return mlist; + b1 = pawns & pos.attacks_from(pos.ep_square(), Them); - while (b) - { - Square from = pop_1st_bit(&b); - if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) - || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs)) - || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) - continue; + assert(b1 != EmptyBoardBB); - Bitboard bb = pos.attacks_from(from) & checkSqs; - SERIALIZE_MOVES(bb); + while (b1) + { + to = pop_1st_bit(&b1); + (*mlist++).move = make_ep_move(to, pos.ep_square()); + } } return mlist; } template - MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist) { + MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) { - Color us = pos.side_to_move(); + Color them = opposite_color(us); + Square ksq = pos.king_square(us); - 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)); - 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; - 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)); - 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; - // 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; - 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 ( 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); - if (!illegal) - (*mlist++).move = make_castle_move(ksq, rsq); - } return mlist; } - bool castling_is_check(const Position& pos, CastlingSide side) { - - // After castling opponent king is attacked by the castled rook? - File rookFile = (side == QUEEN_SIDE ? FILE_D : FILE_F); - Color us = pos.side_to_move(); - Square ksq = pos.king_square(us); - Bitboard occ = pos.occupied_squares(); - - clear_bit(&occ, ksq); // Remove our king from the board - Square rsq = make_square(rookFile, square_rank(ksq)); - return bit_is_set(rook_attacks_bb(rsq, occ), pos.king_square(opposite_color(us))); - } -} +} // namespace