X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=c9d6a90d7d00c191db4080c63af14a9ea6ec4e68;hp=833cd2fc88ec74d94ae19599408715621773baa6;hb=0db374777e793f60bb897d078b3ab641613112ad;hpb=cf5d683408a2ef8a1c80be9bf7d6790a38b16277 diff --git a/src/movegen.cpp b/src/movegen.cpp index 833cd2fc..c9d6a90d 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 @@ -25,67 +23,24 @@ namespace { - template - ExtMove* generate_castling(const Position& pos, ExtMove* moveList) { - - constexpr CastlingRight Cr = Us | Cs; - constexpr bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO); - - if (pos.castling_impeded(Cr) || !pos.can_castle(Cr)) - return moveList; - - // After castling, the rook and king final positions are the same in Chess960 - // as they would be in standard chess. - Square kfrom = pos.square(Us); - Square rfrom = pos.castling_rook_square(Cr); - Square kto = relative_square(Us, KingSide ? SQ_G1 : SQ_C1); - Bitboard enemies = pos.pieces(~Us); - - assert(!pos.checkers()); - - const Direction step = Chess960 ? kto > kfrom ? WEST : EAST - : KingSide ? WEST : EAST; - - for (Square s = kto; s != kfrom; s += step) - if (pos.attackers_to(s) & enemies) - return moveList; - - // 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; - - Move m = make(kfrom, rfrom); - - if (Checks && !pos.gives_check(m)) - return moveList; - - *moveList++ = m; - return moveList; - } - - template 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; } @@ -93,16 +48,14 @@ namespace { template ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard target) { - // Compute our parametrized parameters at compile time, named according to - // the point of view of white side. - constexpr Color Them = (Us == WHITE ? BLACK : WHITE); - constexpr Bitboard TRank8BB = (Us == WHITE ? Rank8BB : Rank1BB); + 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; @@ -127,19 +80,17 @@ 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 dcCandidates = pos.blockers_for_king(Them); - if (pawnsNotOn7 & dcCandidates) + Bitboard dcCandidateQuiets = pos.blockers_for_king(Them) & pawnsNotOn7; + if (dcCandidateQuiets) { - Bitboard dc1 = shift(pawnsNotOn7 & dcCandidates) & emptySquares & ~file_bb(ksq); + Bitboard dc1 = shift(dcCandidateQuiets) & emptySquares & ~file_bb(ksq); Bitboard dc2 = shift(dc1 & TRank3BB) & emptySquares; b1 |= dc1; @@ -161,7 +112,7 @@ namespace { } // Promotions and underpromotions - if (pawnsOn7 && (Type != EVASIONS || (target & TRank8BB))) + if (pawnsOn7) { if (Type == CAPTURES) emptySquares = ~pos.pieces(); @@ -173,8 +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); @@ -185,7 +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; @@ -207,18 +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()); } } @@ -227,29 +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)); @@ -260,36 +201,53 @@ namespace { template - ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target) { + ExtMove* generate_all(const Position& pos, ExtMove* moveList) { - constexpr bool Checks = Type == QUIET_CHECKS; + static_assert(Type != LEGAL, "Unsupported type in generate_all()"); + + constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantiations + 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 && Type != EVASIONS && pos.can_castle(Us)) - { - if (pos.is_chess960()) - { - moveList = generate_castling(pos, moveList); - moveList = generate_castling(pos, moveList); - } - else - { - moveList = generate_castling(pos, moveList); - moveList = generate_castling(pos, moveList); - } + 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; @@ -298,29 +256,22 @@ namespace { } // namespace -/// 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. +/// 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 /// -/// generate generates all pseudo-legal captures and -/// non-captures. Returns a pointer to the end of the move list. +/// Returns a pointer to the end of the move list. 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 @@ -329,35 +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 giving check, +/// except castling. 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); } @@ -377,13 +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)); @@ -391,11 +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); } @@ -412,7 +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 && pinned & from_sq(*cur)) || from_sq(*cur) == ksq || type_of(*cur) == EN_PASSANT) && !pos.legal(*cur)) *cur = (--moveList)->move; else