X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=88c31cfa4856643e60ca45c64cfa53706aff1d97;hp=4c609352358cbbf797aa8b0805dbc1e98e7b7e56;hb=6dddcecb09df268d93810a1a38deb116f97672af;hpb=2bceba7f5162198834ca9f3dca0258e7eac1f797 diff --git a/src/movegen.cpp b/src/movegen.cpp index 4c609352..88c31cfa 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -1,8 +1,6 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file) Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -29,22 +27,20 @@ namespace { ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) { if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS) + { *moveList++ = make(to - D, to, QUEEN); + if (attacks_bb(to) & ksq) + *moveList++ = make(to - D, to, KNIGHT); + } if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS) { *moveList++ = make(to - D, to, ROOK); *moveList++ = make(to - D, to, BISHOP); - *moveList++ = make(to - D, to, KNIGHT); + if (!(attacks_bb(to) & ksq)) + *moveList++ = make(to - D, to, KNIGHT); } - // 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 && (PseudoAttacks[KNIGHT][to] & ksq)) - *moveList++ = make(to - D, to, KNIGHT); - else - (void)ksq; // Silence a warning under MSVC - return moveList; } @@ -52,14 +48,14 @@ namespace { template ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) { - // Compute some compile time parameters relative to the white side - constexpr Color Them = (Us == WHITE ? BLACK : WHITE); + constexpr Color Them = ~Us; constexpr Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB); constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); - constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH); + constexpr Direction Up = pawn_push(Us); constexpr Direction UpRight = (Us == WHITE ? NORTH_EAST : SOUTH_WEST); constexpr Direction UpLeft = (Us == WHITE ? NORTH_WEST : SOUTH_EAST); + const Square ksq = pos.square(Them); Bitboard emptySquares; Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB; @@ -84,14 +80,12 @@ namespace { if (Type == QUIET_CHECKS) { - Square ksq = pos.square(Them); - - b1 &= pos.attacks_from(ksq, Them); - b2 &= pos.attacks_from(ksq, Them); + b1 &= pawn_attacks_bb(Them, ksq); + b2 &= pawn_attacks_bb(Them, ksq); // 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 + // don't generate captures. Note that a possible discovered check // promotion has been already generated amongst the captures. Bitboard dcCandidateQuiets = pos.blockers_for_king(Them) & pawnsNotOn7; if (dcCandidateQuiets) @@ -130,8 +124,6 @@ namespace { Bitboard b2 = shift(pawnsOn7) & enemies; Bitboard b3 = shift(pawnsOn7) & emptySquares; - Square ksq = pos.square(Them); - while (b1) moveList = make_promotions(moveList, pop_lsb(&b1), ksq); @@ -142,7 +134,7 @@ namespace { moveList = make_promotions(moveList, pop_lsb(&b3), ksq); } - // Standard and en-passant captures + // Standard and en passant captures if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS) { Bitboard b1 = shift(pawnsNotOn7) & enemies; @@ -164,18 +156,16 @@ namespace { { assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6)); - // 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))) + // An en passant capture cannot resolve a discovered check. + if (Type == EVASIONS && (target & (pos.ep_square() + Up))) return moveList; - b1 = pawnsNotOn7 & pos.attacks_from(pos.ep_square(), Them); + b1 = pawnsNotOn7 & pawn_attacks_bb(Them, pos.ep_square()); assert(b1); while (b1) - *moveList++ = make(pop_lsb(&b1), pos.ep_square()); + *moveList++ = make(pop_lsb(&b1), pos.ep_square()); } } @@ -184,29 +174,23 @@ namespace { template - ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us, - Bitboard target) { + ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard piecesToMove, Bitboard target) { - assert(Pt != KING && Pt != PAWN); + static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()"); - const Square* pl = pos.squares(us); + Bitboard bb = piecesToMove & pos.pieces(Pt); - for (Square from = *pl; from != SQ_NONE; from = *++pl) - { - if (Checks) - { - if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN) - && !(PseudoAttacks[Pt][from] & target & pos.check_squares(Pt))) - continue; + if (!bb) + return moveList; - if (pos.blockers_for_king(~us) & from) - continue; - } + [[maybe_unused]] const Bitboard checkSquares = pos.check_squares(Pt); - Bitboard b = pos.attacks_from(from) & target; + while (bb) { + Square from = pop_lsb(&bb); - if (Checks) - b &= pos.check_squares(Pt); + Bitboard b = attacks_bb(from, pos.pieces()) & target; + if constexpr (Checks) + b &= checkSquares; while (b) *moveList++ = make_move(from, pop_lsb(&b)); @@ -217,33 +201,53 @@ namespace { template - ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target) { + ExtMove* generate_all(const Position& pos, ExtMove* moveList) { + + static_assert(Type != LEGAL, "Unsupported type in generate_all()"); - constexpr CastlingRight OO = Us | KING_SIDE; - constexpr CastlingRight OOO = Us | QUEEN_SIDE; constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantations + Bitboard target, piecesToMove = pos.pieces(Us); + + if(Type == QUIET_CHECKS) + piecesToMove &= ~pos.blockers_for_king(~Us); + + switch (Type) + { + case CAPTURES: + target = pos.pieces(~Us); + break; + case QUIETS: + case QUIET_CHECKS: + target = ~pos.pieces(); + break; + case EVASIONS: + { + Square checksq = lsb(pos.checkers()); + target = between_bb(pos.square(Us), checksq) | checksq; + break; + } + case NON_EVASIONS: + target = ~pos.pieces(Us); + break; + } moveList = generate_pawn_moves(pos, moveList, target); - moveList = generate_moves(pos, moveList, Us, target); - moveList = generate_moves(pos, moveList, Us, target); - moveList = generate_moves< ROOK, Checks>(pos, moveList, Us, target); - moveList = generate_moves< QUEEN, Checks>(pos, moveList, Us, target); + moveList = generate_moves(pos, moveList, piecesToMove, target); + moveList = generate_moves(pos, moveList, piecesToMove, target); + moveList = generate_moves< ROOK, Checks>(pos, moveList, piecesToMove, target); + moveList = generate_moves< QUEEN, Checks>(pos, moveList, piecesToMove, target); if (Type != QUIET_CHECKS && Type != EVASIONS) { Square ksq = pos.square(Us); - Bitboard b = pos.attacks_from(ksq) & target; + Bitboard b = attacks_bb(ksq) & target; while (b) *moveList++ = make_move(ksq, pop_lsb(&b)); - if (Type != CAPTURES && pos.can_castle(CastlingRight(OO | OOO))) - { - if (!pos.castling_impeded(OO) && pos.can_castle(OO)) - *moveList++ = make(ksq, pos.castling_rook_square(OO)); - - if (!pos.castling_impeded(OOO) && pos.can_castle(OOO)) - *moveList++ = make(ksq, pos.castling_rook_square(OOO)); - } + if ((Type != CAPTURES) && pos.can_castle(Us & ANY_CASTLING)) + for (CastlingRights cr : { Us & KING_SIDE, Us & QUEEN_SIDE } ) + if (!pos.castling_impeded(cr) && pos.can_castle(cr)) + *moveList++ = make(ksq, pos.castling_rook_square(cr)); } return moveList; @@ -252,8 +256,8 @@ namespace { } // namespace -/// Generates all pseudo-legal captures and queen promotions -/// Generates all pseudo-legal non-captures and underpromotions +/// Generates all pseudo-legal captures plus queen and checking knight promotions +/// Generates all pseudo-legal non-captures and underpromotions(except checking knight) /// Generates all pseudo-legal captures and non-captures /// /// Returns a pointer to the end of the move list. @@ -261,17 +265,13 @@ namespace { template ExtMove* generate(const Position& pos, ExtMove* moveList) { - assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS); + static_assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS, "Unsupported type in generate()"); assert(!pos.checkers()); Color us = pos.side_to_move(); - Bitboard target = Type == CAPTURES ? pos.pieces(~us) - : Type == QUIETS ? ~pos.pieces() - : Type == NON_EVASIONS ? ~pos.pieces(us) : 0; - - return us == WHITE ? generate_all(pos, moveList, target) - : generate_all(pos, moveList, target); + return us == WHITE ? generate_all(pos, moveList) + : generate_all(pos, moveList); } // Explicit template instantiations @@ -280,35 +280,32 @@ template ExtMove* generate(const Position&, ExtMove*); template ExtMove* generate(const Position&, ExtMove*); -/// generate generates all pseudo-legal non-captures and knight -/// underpromotions that give check. Returns a pointer to the end of the move list. +/// generate generates all pseudo-legal non-captures. +/// Returns a pointer to the end of the move list. template<> ExtMove* generate(const Position& pos, ExtMove* moveList) { assert(!pos.checkers()); Color us = pos.side_to_move(); - Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us); + Bitboard dc = pos.blockers_for_king(~us) & pos.pieces(us) & ~pos.pieces(PAWN); while (dc) { Square from = pop_lsb(&dc); PieceType pt = type_of(pos.piece_on(from)); - if (pt == PAWN) - continue; // Will be generated together with direct checks - - Bitboard b = pos.attacks_from(pt, from) & ~pos.pieces(); + Bitboard b = attacks_bb(pt, from, pos.pieces()) & ~pos.pieces(); if (pt == KING) - b &= ~PseudoAttacks[QUEEN][pos.square(~us)]; + b &= ~attacks_bb(pos.square(~us)); while (b) *moveList++ = make_move(from, pop_lsb(&b)); } - return us == WHITE ? generate_all(pos, moveList, ~pos.pieces()) - : generate_all(pos, moveList, ~pos.pieces()); + return us == WHITE ? generate_all(pos, moveList) + : generate_all(pos, moveList); } @@ -328,13 +325,10 @@ ExtMove* generate(const Position& pos, ExtMove* moveList) { // 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; - } + sliderAttacks |= line_bb(ksq, pop_lsb(&sliders)) & ~pos.checkers(); // Generate evasions for king, capture and non capture moves - Bitboard b = pos.attacks_from(ksq) & ~pos.pieces(us) & ~sliderAttacks; + Bitboard b = attacks_bb(ksq) & ~pos.pieces(us) & ~sliderAttacks; while (b) *moveList++ = make_move(ksq, pop_lsb(&b)); @@ -342,11 +336,8 @@ ExtMove* generate(const Position& pos, ExtMove* moveList) { return moveList; // Double check, only a king move can save the day // Generate blocking evasions or captures of the checking piece - Square checksq = lsb(pos.checkers()); - Bitboard target = between_bb(checksq, ksq) | checksq; - - return us == WHITE ? generate_all(pos, moveList, target) - : generate_all(pos, moveList, target); + return us == WHITE ? generate_all(pos, moveList) + : generate_all(pos, moveList); } @@ -363,7 +354,7 @@ ExtMove* generate(const Position& pos, ExtMove* moveList) { moveList = pos.checkers() ? generate(pos, moveList) : generate(pos, moveList); while (cur != moveList) - if ( (pinned || from_sq(*cur) == ksq || type_of(*cur) == ENPASSANT) + if ( (pinned || from_sq(*cur) == ksq || type_of(*cur) == EN_PASSANT) && !pos.legal(*cur)) *cur = (--moveList)->move; else