X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=5095bb7455e6f36966d884ea297a8431b363183a;hp=d8c4370ac83505334f2e0a550dc8b8329a825ec6;hb=ca3c1c5f3a5f011edd04af856cdd59bdaefe423d;hpb=4b509559fbabe8a41cb8387c71d07bb1c7b78d6f diff --git a/src/movegen.cpp b/src/movegen.cpp index d8c4370a..5095bb74 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -26,21 +26,16 @@ namespace Stockfish { namespace { template - ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) { + ExtMove* make_promotions(ExtMove* moveList, Square to) { 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); - if (!(attacks_bb(to) & ksq)) - *moveList++ = make(to - D, to, KNIGHT); + *moveList++ = make(to - D, to, KNIGHT); } return moveList; @@ -57,20 +52,16 @@ namespace { 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; + const Bitboard emptySquares = ~pos.pieces(); + const Bitboard enemies = Type == EVASIONS ? pos.checkers() + : pos.pieces(Them); Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB; Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB; - Bitboard enemies = (Type == EVASIONS ? pos.pieces(Them) & target: - Type == CAPTURES ? target : pos.pieces(Them)); - // Single and double pawn pushes, no promotions if (Type != CAPTURES) { - emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces()); - Bitboard b1 = shift(pawnsNotOn7) & emptySquares; Bitboard b2 = shift(b1 & TRank3BB) & emptySquares; @@ -82,33 +73,24 @@ namespace { if (Type == QUIET_CHECKS) { - 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 discovered check - // promotion has been already generated amongst the captures. - Bitboard dcCandidateQuiets = pos.blockers_for_king(Them) & pawnsNotOn7; - if (dcCandidateQuiets) - { - Bitboard dc1 = shift(dcCandidateQuiets) & emptySquares & ~file_bb(ksq); - Bitboard dc2 = shift(dc1 & TRank3BB) & emptySquares; - - b1 |= dc1; - b2 |= dc2; - } + // To make a quiet check, you either make a direct check by pushing a pawn + // or push a blocker pawn that is not on the same file as the enemy king. + // Discovered check promotion has been already generated amongst the captures. + Square ksq = pos.square(Them); + Bitboard dcCandidatePawns = pos.blockers_for_king(Them) & ~file_bb(ksq); + b1 &= pawn_attacks_bb(Them, ksq) | shift< Up>(dcCandidatePawns); + b2 &= pawn_attacks_bb(Them, ksq) | shift(dcCandidatePawns); } while (b1) { - Square to = pop_lsb(&b1); + Square to = pop_lsb(b1); *moveList++ = make_move(to - Up, to); } while (b2) { - Square to = pop_lsb(&b2); + Square to = pop_lsb(b2); *moveList++ = make_move(to - Up - Up, to); } } @@ -116,24 +98,21 @@ namespace { // Promotions and underpromotions if (pawnsOn7) { - if (Type == CAPTURES) - emptySquares = ~pos.pieces(); - - if (Type == EVASIONS) - emptySquares &= target; - Bitboard b1 = shift(pawnsOn7) & enemies; Bitboard b2 = shift(pawnsOn7) & enemies; Bitboard b3 = shift(pawnsOn7) & emptySquares; + if (Type == EVASIONS) + b3 &= target; + while (b1) - moveList = make_promotions(moveList, pop_lsb(&b1), ksq); + moveList = make_promotions(moveList, pop_lsb(b1)); while (b2) - moveList = make_promotions(moveList, pop_lsb(&b2), ksq); + moveList = make_promotions(moveList, pop_lsb(b2)); while (b3) - moveList = make_promotions(moveList, pop_lsb(&b3), ksq); + moveList = make_promotions(moveList, pop_lsb(b3)); } // Standard and en passant captures @@ -144,13 +123,13 @@ namespace { while (b1) { - Square to = pop_lsb(&b1); + Square to = pop_lsb(b1); *moveList++ = make_move(to - UpRight, to); } while (b2) { - Square to = pop_lsb(&b2); + Square to = pop_lsb(b2); *moveList++ = make_move(to - UpLeft, to); } @@ -158,7 +137,7 @@ namespace { { assert(rank_of(pos.ep_square()) == relative_rank(Us, RANK_6)); - // An en passant capture cannot resolve a discovered check. + // An en passant capture cannot resolve a discovered check if (Type == EVASIONS && (target & (pos.ep_square() + Up))) return moveList; @@ -167,7 +146,7 @@ namespace { assert(b1); while (b1) - *moveList++ = make(pop_lsb(&b1), pos.ep_square()); + *moveList++ = make(pop_lsb(b1), pos.ep_square()); } } @@ -175,22 +154,24 @@ namespace { } - template - ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard piecesToMove, Bitboard target) { + template + ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Bitboard target) { static_assert(Pt != KING && Pt != PAWN, "Unsupported piece type in generate_moves()"); - Bitboard bb = piecesToMove & pos.pieces(Pt); - - while (bb) { - Square from = pop_lsb(&bb); + Bitboard bb = pos.pieces(Us, Pt); + while (bb) + { + Square from = pop_lsb(bb); Bitboard b = attacks_bb(from, pos.pieces()) & target; - if constexpr (Checks) + + // To check, you either move freely a blocker or make a direct check. + if (Checks && (Pt == QUEEN || !(pos.blockers_for_king(~Us) & from))) b &= pos.check_squares(Pt); while (b) - *moveList++ = make_move(from, pop_lsb(&b)); + *moveList++ = make_move(from, pop_lsb(b)); } return moveList; @@ -203,42 +184,34 @@ namespace { static_assert(Type != LEGAL, "Unsupported type in generate_all()"); constexpr bool Checks = Type == QUIET_CHECKS; // Reduce template instantiations - Bitboard target, piecesToMove = pos.pieces(Us); + const Square ksq = pos.square(Us); + Bitboard target; - if(Type == QUIET_CHECKS) - piecesToMove &= ~pos.blockers_for_king(~Us); - - switch (Type) + // Skip generating non-king moves when in double check + if (Type != EVASIONS || !more_than_one(pos.checkers())) { - case CAPTURES: - target = pos.pieces(~Us); - break; - case QUIETS: - case QUIET_CHECKS: - target = ~pos.pieces(); - break; - case EVASIONS: - target = between_bb(pos.square(Us), lsb(pos.checkers())) | pos.checkers(); - break; - case NON_EVASIONS: - target = ~pos.pieces(Us); - break; + target = Type == EVASIONS ? between_bb(ksq, lsb(pos.checkers())) + : Type == NON_EVASIONS ? ~pos.pieces( Us) + : Type == CAPTURES ? pos.pieces(~Us) + : ~pos.pieces( ); // QUIETS || QUIET_CHECKS + + moveList = generate_pawn_moves(pos, moveList, target); + moveList = generate_moves(pos, moveList, target); + moveList = generate_moves(pos, moveList, target); + moveList = generate_moves(pos, moveList, target); + moveList = generate_moves(pos, moveList, target); } - moveList = generate_pawn_moves(pos, moveList, 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) + if (!Checks || pos.blockers_for_king(~Us) & ksq) { - Square ksq = pos.square(Us); - Bitboard b = attacks_bb(ksq) & target; + Bitboard b = attacks_bb(ksq) & (Type == EVASIONS ? ~pos.pieces(Us) : target); + if (Checks) + b &= ~attacks_bb(pos.square(~Us)); + while (b) - *moveList++ = make_move(ksq, pop_lsb(&b)); + *moveList++ = make_move(ksq, pop_lsb(b)); - if ((Type != CAPTURES) && pos.can_castle(Us & ANY_CASTLING)) + if ((Type == QUIETS || Type == NON_EVASIONS) && 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)); @@ -250,8 +223,10 @@ namespace { } // namespace -/// 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 plus queen promotions +/// Generates all pseudo-legal non-captures and underpromotions +/// Generates all pseudo-legal check evasions when the side to move is in check +/// Generates all pseudo-legal non-captures giving check, except castling and promotions /// Generates all pseudo-legal captures and non-captures /// /// Returns a pointer to the end of the move list. @@ -259,8 +234,8 @@ namespace { template ExtMove* generate(const Position& pos, ExtMove* moveList) { - static_assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS, "Unsupported type in generate()"); - assert(!pos.checkers()); + static_assert(Type != LEGAL, "Unsupported type in generate()"); + assert((Type == EVASIONS) == (bool)pos.checkers()); Color us = pos.side_to_move(); @@ -271,70 +246,11 @@ ExtMove* generate(const Position& pos, ExtMove* moveList) { // Explicit template instantiations template ExtMove* generate(const Position&, ExtMove*); template ExtMove* generate(const Position&, ExtMove*); +template ExtMove* generate(const Position&, ExtMove*); +template ExtMove* generate(const Position&, ExtMove*); template ExtMove* generate(const Position&, ExtMove*); -/// 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) & ~pos.pieces(PAWN); - - while (dc) - { - Square from = pop_lsb(&dc); - PieceType pt = type_of(pos.piece_on(from)); - - Bitboard b = attacks_bb(pt, from, pos.pieces()) & ~pos.pieces(); - - if (pt == KING) - b &= ~attacks_bb(pos.square(~us)); - - while (b) - *moveList++ = make_move(from, pop_lsb(&b)); - } - - return us == WHITE ? generate_all(pos, moveList) - : generate_all(pos, moveList); -} - - -/// 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) { - - assert(pos.checkers()); - - Color us = pos.side_to_move(); - Square ksq = pos.square(us); - Bitboard sliderAttacks = 0; - Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN); - - // 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) - sliderAttacks |= line_bb(ksq, pop_lsb(&sliders)) & ~pos.checkers(); - - // Generate evasions for king, capture and non capture moves - Bitboard b = attacks_bb(ksq) & ~pos.pieces(us) & ~sliderAttacks; - while (b) - *moveList++ = make_move(ksq, pop_lsb(&b)); - - if (more_than_one(pos.checkers())) - return moveList; // Double check, only a king move can save the day - - // Generate blocking evasions or captures of the checking piece - return us == WHITE ? generate_all(pos, moveList) - : generate_all(pos, moveList); -} - - /// generate generates all the legal moves in the given position template<>