X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=bfc8858aba912539e8c016ada7b2636d3d507120;hp=297b51ffdeacb7e6d633be647d9e3da3a89ffc49;hb=950c8436edc50857b83eb3e0cbaca06407764655;hpb=45ce92b89c9191f1606d82611620587157956e1b diff --git a/src/movegen.cpp b/src/movegen.cpp index 297b51ff..bfc8858a 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) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 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 @@ -19,524 +19,400 @@ #include -#include "bitcount.h" #include "movegen.h" - -// Simple macro to wrap a very common while loop, no facny, no flexibility, -// hardcoded list name 'mlist' and from square 'from'. -#define SERIALIZE_MOVES(b) while (b) (*mlist++).move = make_move(from, pop_1st_bit(&b)) - -// 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); } +#include "position.h" namespace { - enum CastlingSide { - KING_SIDE, - QUEEN_SIDE - }; - - template - MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us); - - template - MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square); - - template - inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) { - - assert(Pt != QUEEN); - - Bitboard b = pos.attacks_from(from) & pos.empty_squares(); - if (Pt == KING) - { - Square ksq = pos.king_square(opposite_color(pos.side_to_move())); - b &= ~QueenPseudoAttacks[ksq]; - } - SERIALIZE_MOVES(b); - return mlist; - } + template + ExtMove* generate_castling(const Position& pos, ExtMove* moveList, Color us, const CheckInfo* ci) { - template - inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us, - Bitboard dc, Square ksq) { - assert(Pt != KING); + static const bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO); - Bitboard checkSqs, b; - Square from; - const Square* ptr = pos.piece_list_begin(us, Pt); + if (pos.castling_impeded(Cr) || !pos.can_castle(Cr)) + return moveList; - if ((from = *ptr++) == SQ_NONE) - 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.castling_rook_square(Cr); + Square kto = relative_square(us, KingSide ? SQ_G1 : SQ_C1); + Bitboard enemies = pos.pieces(~us); - checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); + assert(!pos.checkers()); - do - { - if ( (Pt == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) - || (Pt == ROOK && !(RookPseudoAttacks[from] & checkSqs)) - || (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) - continue; + const Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E + : KingSide ? DELTA_W : DELTA_E; - if (dc && bit_is_set(dc, from)) - continue; + for (Square s = kto; s != kfrom; s += K) + if (pos.attackers_to(s) & enemies) + return moveList; - b = pos.attacks_from(from) & checkSqs; - SERIALIZE_MOVES(b); + // 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 (Chess960 && (attacks_bb(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN))) + return moveList; - } while ((from = *ptr++) != SQ_NONE); + Move m = make(kfrom, rfrom); - return mlist; - } + if (Checks && !pos.gives_check(m, *ci)) + return moveList; - template<> - FORCE_INLINE MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { + (moveList++)->move = m; - return (us == WHITE ? generate_pawn_moves(p, m, dc, ksq) - : generate_pawn_moves(p, m, dc, ksq)); + return moveList; } - template - FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) { - - 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)); - } - template - FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { + template + inline ExtMove* make_promotions(ExtMove* moveList, Square to, const CheckInfo* ci) { - Bitboard b; - Square from; - const Square* ptr = pos.piece_list_begin(us, Pt); + if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS) + (moveList++)->move = make(to - Delta, to, QUEEN); - if (*ptr != SQ_NONE) + if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS) { - do { - from = *ptr; - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - } while (*++ptr != SQ_NONE); + (moveList++)->move = make(to - Delta, to, ROOK); + (moveList++)->move = make(to - Delta, to, BISHOP); + (moveList++)->move = make(to - Delta, to, KNIGHT); } - return mlist; - } - - template<> - FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { - Bitboard b; - Square from = pos.king_square(us); + // Knight promotion is the only promotion that can give a direct check + // that's not already included in the queen promotion. + if (Type == QUIET_CHECKS && (StepAttacksBB[W_KNIGHT][to] & ci->ksq)) + (moveList++)->move = make(to - Delta, to, KNIGHT); + else + (void)ci; // Silence a warning under MSVC - b = pos.attacks_from(from) & target; - SERIALIZE_MOVES(b); - return mlist; + return moveList; } -} + template + ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, + Bitboard target, const CheckInfo* ci) { -/// 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. + // 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); -template -MoveStack* generate(const Position& pos, MoveStack* mlist) { + Bitboard emptySquares; - assert(pos.is_ok()); - assert(!pos.in_check()); + Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB; + Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB; - Color us = pos.side_to_move(); - Bitboard target; + Bitboard enemies = (Type == EVASIONS ? pos.pieces(Them) & target: + Type == CAPTURES ? target : pos.pieces(Them)); - 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); + // Single and double pawn pushes, no promotions + if (Type != CAPTURES) + { + emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces()); - 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); + Bitboard b1 = shift_bb(pawnsNotOn7) & emptySquares; + Bitboard b2 = shift_bb(b1 & TRank3BB) & emptySquares; - 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); + if (Type == EVASIONS) // Consider only blocking squares + { + b1 &= target; + b2 &= target; + } - if (Type != MV_CAPTURE) - { - if (pos.can_castle_kingside(us)) - mlist = generate_castle_moves(pos, mlist, us); + if (Type == QUIET_CHECKS) + { + b1 &= pos.attacks_from(ci->ksq, Them); + b2 &= pos.attacks_from(ci->ksq, Them); - if (pos.can_castle_queenside(us)) - mlist = generate_castle_moves(pos, mlist, us); - } + // 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 amongst the captures. + if (pawnsNotOn7 & ci->dcCandidates) + { + Bitboard dc1 = shift_bb(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq); + Bitboard dc2 = shift_bb(dc1 & TRank3BB) & emptySquares; - return mlist; -} + b1 |= dc1; + b2 |= dc2; + } + } -// 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); + while (b1) + { + Square to = pop_lsb(&b1); + (moveList++)->move = make_move(to - Up, to); + } + while (b2) + { + Square to = pop_lsb(&b2); + (moveList++)->move = make_move(to - Up - Up, to); + } + } -/// 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) { + // Promotions and underpromotions + if (pawnsOn7 && (Type != EVASIONS || (target & TRank8BB))) + { + if (Type == CAPTURES) + emptySquares = ~pos.pieces(); - assert(pos.is_ok()); - assert(!pos.in_check()); + if (Type == EVASIONS) + emptySquares &= target; - Bitboard b, dc; - Square from; - Color us = pos.side_to_move(); - Square ksq = pos.king_square(opposite_color(us)); + Bitboard b1 = shift_bb(pawnsOn7) & enemies; + Bitboard b2 = shift_bb(pawnsOn7) & enemies; + Bitboard b3 = shift_bb(pawnsOn7) & emptySquares; - assert(pos.piece_on(ksq) == make_piece(opposite_color(us), KING)); + while (b1) + moveList = make_promotions(moveList, pop_lsb(&b1), ci); - // Discovered non-capture checks - b = dc = pos.discovered_check_candidates(us); + while (b2) + moveList = make_promotions(moveList, pop_lsb(&b2), ci); - 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; - } - } + while (b3) + moveList = make_promotions(moveList, pop_lsb(&b3), ci); + } - // 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); -} + // Standard and en-passant captures + if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS) + { + Bitboard b1 = shift_bb(pawnsNotOn7) & enemies; + Bitboard b2 = shift_bb(pawnsNotOn7) & enemies; + while (b1) + { + Square to = pop_lsb(&b1); + (moveList++)->move = make_move(to - Right, to); + } -/// 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) { + while (b2) + { + Square to = pop_lsb(&b2); + (moveList++)->move = make_move(to - Left, to); + } - assert(pos.is_ok()); - assert(pos.in_check()); + if (pos.ep_square() != SQ_NONE) + { + assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6)); - Bitboard b, target; - Square from, checksq; - int checkersCnt = 0; - Color us = pos.side_to_move(); - Square ksq = pos.king_square(us); - Bitboard checkers = pos.checkers(); - Bitboard sliderAttacks = EmptyBoardBB; + // 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 == EVASIONS && !(target & (pos.ep_square() - Up))) + return moveList; - assert(pos.piece_on(ksq) == make_piece(us, KING)); - assert(checkers); + b1 = pawnsNotOn7 & pos.attacks_from(pos.ep_square(), Them); - // Find squares attacked by slider checkers, we will remove - // them from the king evasions set so to early skip known - // illegal moves and avoid an useless legality check later. - b = checkers; - do - { - checkersCnt++; - checksq = pop_1st_bit(&b); - - assert(pos.color_of_piece_on(checksq) == opposite_color(us)); - - switch (pos.type_of_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 (RookPseudoAttacks[checksq] & (1ULL << ksq)) - sliderAttacks |= RookPseudoAttacks[checksq] | pos.attacks_from(checksq); - else - sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from(checksq); - default: - break; - } - } while (b); + assert(b1); - // 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); - - // Generate evasions for other pieces only if not double check - if (checkersCnt > 1) - return mlist; - - // Find squares where a blocking evasion or a capture of the - // 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); - return generate_piece_moves(pos, mlist, us, target); -} + while (b1) + (moveList++)->move = make(pop_lsb(&b1), pos.ep_square()); + } + } + return moveList; + } -/// generate computes a complete list of legal -/// or pseudo-legal moves in the current position. -template<> -MoveStack* generate(const Position& pos, MoveStack* mlist) { - assert(pos.is_ok()); + template FORCE_INLINE + ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us, + Bitboard target, const CheckInfo* ci) { - return pos.in_check() ? generate(pos, mlist) - : generate(pos, mlist); -} + assert(Pt != KING && Pt != PAWN); -template<> -MoveStack* generate(const Position& pos, MoveStack* mlist) { + const Square* pl = pos.list(us); - assert(pos.is_ok()); + for (Square from = *pl; from != SQ_NONE; from = *++pl) + { + if (Checks) + { + if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN) + && !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt])) + continue; - MoveStack *last, *cur = mlist; - Bitboard pinned = pos.pinned_pieces(pos.side_to_move()); + if (ci->dcCandidates && (ci->dcCandidates & from)) + continue; + } - last = generate(pos, mlist); + Bitboard b = pos.attacks_from(from) & target; - // Remove illegal moves from the list - while (cur != last) - if (!pos.pl_move_is_legal(cur->move, pinned)) - cur->move = (--last)->move; - else - cur++; + if (Checks) + b &= ci->checkSq[Pt]; - return last; -} + while (b) + (moveList++)->move = make_move(from, pop_lsb(&b)); + } + return moveList; + } -namespace { - template - inline Bitboard move_pawns(Bitboard p) { + template FORCE_INLINE + ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target, + const CheckInfo* ci = NULL) { - 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; - } + const bool Checks = Type == QUIET_CHECKS; - template - inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) { + moveList = generate_pawn_moves(pos, moveList, target, ci); + moveList = generate_moves(pos, moveList, Us, target, ci); + moveList = generate_moves(pos, moveList, Us, target, ci); + moveList = generate_moves< ROOK, Checks>(pos, moveList, Us, target, ci); + moveList = generate_moves< QUEEN, Checks>(pos, moveList, Us, target, ci); - const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); + if (Type != QUIET_CHECKS && Type != EVASIONS) + { + Square ksq = pos.king_square(Us); + Bitboard b = pos.attacks_from(ksq) & target; + while (b) + (moveList++)->move = make_move(ksq, pop_lsb(&b)); + } - Bitboard b; - Square to; + if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(Us)) + { + if (pos.is_chess960()) + { + moveList = generate_castling::right, Checks, true>(pos, moveList, Us, ci); + moveList = generate_castling::right, Checks, true>(pos, moveList, Us, ci); + } + else + { + moveList = generate_castling::right, Checks, false>(pos, moveList, Us, ci); + moveList = generate_castling::right, Checks, false>(pos, moveList, Us, ci); + } + } - // 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; + return moveList; } - template - inline MoveStack* generate_promotions(const Position& pos, MoveStack* mlist, Bitboard pawnsOn7, Bitboard target) { - - const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); +} // namespace - Bitboard b; - Square to; - // Promotions and under-promotions, both captures and non-captures - b = move_pawns(pawnsOn7) & target; +/// 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. - if (Delta != DELTA_N && Delta != DELTA_S) - b &= ~TFileABB; +template +ExtMove* generate(const Position& pos, ExtMove* moveList) { - while (b) - { - to = pop_1st_bit(&b); + assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS); + assert(!pos.checkers()); - if (Type == MV_CAPTURE || Type == MV_EVASION) - (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN); + Color us = pos.side_to_move(); - 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); - } + Bitboard target = Type == CAPTURES ? pos.pieces(~us) + : Type == QUIETS ? ~pos.pieces() + : Type == NON_EVASIONS ? ~pos.pieces(us) : 0; - // 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; - } + return us == WHITE ? generate_all(pos, moveList, target) + : generate_all(pos, moveList, target); +} - template - 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(pawns & ~TRank7BB) & emptySquares; - } +// Explicit template instantiations +template ExtMove* generate(const Position&, ExtMove*); +template ExtMove* generate(const Position&, ExtMove*); +template ExtMove* generate(const Position&, ExtMove*); - 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(); +/// generate generates all pseudo-legal non-captures and knight +/// underpromotions that give check. Returns a pointer to the end of the move list. +template<> +ExtMove* generate(const Position& pos, ExtMove* moveList) { - pawns &= ~TRank7BB; - mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces); - mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces); - mlist = generate_promotions(pos, mlist, pawnsOn7, emptySquares); - } + assert(!pos.checkers()); - // Standard captures - if (Type == MV_CAPTURE || Type == MV_EVASION) - { - mlist = generate_pawn_captures(mlist, pawns, enemyPieces); - mlist = generate_pawn_captures(mlist, pawns, enemyPieces); - } + Color us = pos.side_to_move(); + CheckInfo ci(pos); + Bitboard dc = ci.dcCandidates; - // Single and double pawn pushes - if (Type != MV_CAPTURE) - { - b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares); - b2 = move_pawns(pawnPushes & TRank3BB) & emptySquares; + while (dc) + { + Square from = pop_lsb(&dc); + PieceType pt = type_of(pos.piece_on(from)); - if (Type == MV_CHECK) - { - // Consider only pawn moves which give direct checks - b1 &= pos.attacks_from(ksq, Them); - b2 &= pos.attacks_from(ksq, Them); + if (pt == PAWN) + continue; // Will be generated together with direct checks - // 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; + Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces(); - b1 |= dc1; - b2 |= dc2; - } - } - SERIALIZE_MOVES_D(b1, -TDELTA_N); - SERIALIZE_MOVES_D(b2, -TDELTA_N -TDELTA_N); - } + if (pt == KING) + b &= ~PseudoAttacks[QUEEN][ci.ksq]; - // En passant captures - 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); + while (b) + (moveList++)->move = make_move(from, pop_lsb(&b)); + } - // 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; + return us == WHITE ? generate_all(pos, moveList, ~pos.pieces(), &ci) + : generate_all(pos, moveList, ~pos.pieces(), &ci); +} - b1 = pawns & pos.attacks_from(pos.ep_square(), Them); - assert(b1 != EmptyBoardBB); +/// generate 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<> +ExtMove* generate(const Position& pos, ExtMove* moveList) { - while (b1) - { - to = pop_1st_bit(&b1); - (*mlist++).move = make_ep_move(to, pos.ep_square()); - } - } - return mlist; - } + assert(pos.checkers()); - template - MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) { + Color us = pos.side_to_move(); + Square ksq = pos.king_square(us); + Bitboard sliderAttacks = 0; + Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN); - Color them = opposite_color(us); - Square ksq = pos.king_square(us); + // Find all the squares attacked by slider checkers. We will remove them from + // the king evasions in order to skip known illegal moves, which avoids any + // useless legality checks later on. + while (sliders) + { + Square checksq = pop_lsb(&sliders); + sliderAttacks |= LineBB[checksq][ksq] ^ checksq; + } - assert(pos.piece_on(ksq) == make_piece(us, KING)); + // Generate evasions for king, capture and non capture moves + Bitboard b = pos.attacks_from(ksq) & ~pos.pieces(us) & ~sliderAttacks; + while (b) + (moveList++)->move = make_move(ksq, pop_lsb(&b)); - 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; + if (more_than_one(pos.checkers())) + return moveList; // Double check, only a king move can save the day - assert(pos.piece_on(rsq) == make_piece(us, ROOK)); + // Generate blocking evasions or captures of the checking piece + Square checksq = lsb(pos.checkers()); + Bitboard target = between_bb(checksq, ksq) | checksq; - // 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; + return us == WHITE ? generate_all(pos, moveList, target) + : generate_all(pos, moveList, target); +} - 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)) == make_piece(them, ROOK) - || pos.piece_on(relative_square(us, SQ_A1)) == make_piece(them, QUEEN))) - illegal = true; +/// generate generates all the legal moves in the given position - if (!illegal) - (*mlist++).move = make_castle_move(ksq, rsq); +template<> +ExtMove* generate(const Position& pos, ExtMove* moveList) { - return mlist; - } + Bitboard pinned = pos.pinned_pieces(pos.side_to_move()); + Square ksq = pos.king_square(pos.side_to_move()); + ExtMove* cur = moveList; + + moveList = pos.checkers() ? generate(pos, moveList) + : generate(pos, moveList); + while (cur != moveList) + if ( (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT) + && !pos.legal(cur->move, pinned)) + cur->move = (--moveList)->move; + else + ++cur; -} // namespace + return moveList; +}