X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=6ef4be4f1507de18f40a583ab87d3275798b9026;hp=bc5b9cdebe17f0232fe77a4311c620bab66e4b4a;hb=8de29390f2d2bd31585b93ff46eae3051126f666;hpb=6f6be95bad6f5371d9979de85f7f5892309b7aee diff --git a/src/movegen.cpp b/src/movegen.cpp index bc5b9cde..6ef4be4f 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -1,7 +1,8 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, 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 @@ -17,122 +18,82 @@ along with this program. If not, see . */ -#include #include #include "movegen.h" #include "position.h" -/// Simple macro to wrap a very common while loop, no facny, no flexibility, -/// hardcoded names 'mlist' and 'from'. -#define SERIALIZE(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_PAWNS(b, d) while (b) { Square to = pop_1st_bit(&b); \ - (*mlist++).move = make_move(to - (d), to); } namespace { - enum CastlingSide { KING_SIDE, QUEEN_SIDE }; - - template - MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) { + template + ExtMove* generate_castling(const Position& pos, ExtMove* moveList, Color us, const CheckInfo* ci) { - const CastleRight CR[] = { Side ? WHITE_OOO : WHITE_OO, - Side ? BLACK_OOO : BLACK_OO }; + static const bool KingSide = (Cr == WHITE_OO || Cr == BLACK_OO); - if (!pos.can_castle(CR[us])) - return mlist; + 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.king_square(us); - Square rfrom = pos.castle_rook_square(CR[us]); - Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1); - Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1); + 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.in_check()); - assert(pos.piece_on(kfrom) == make_piece(us, KING)); - assert(pos.piece_on(rfrom) == make_piece(us, ROOK)); + assert(!pos.checkers()); - // Unimpeded rule: All the squares between the king's initial and final squares - // (including the final square), and all the squares between the rook's initial - // and final squares (including the final square), must be vacant except for - // the king and castling rook. - for (Square s = std::min(rfrom, rto), e = std::max(rfrom, rto); s <= e; s++) - if (s != kfrom && s != rfrom && !pos.square_is_empty(s)) - return mlist; + const Square K = Chess960 ? kto > kfrom ? DELTA_W : DELTA_E + : KingSide ? DELTA_W : DELTA_E; - for (Square s = std::min(kfrom, kto), e = std::max(kfrom, kto); s <= e; s++) - if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s)) - ||(pos.attackers_to(s) & enemies)) - return mlist; + for (Square s = kto; s != kfrom; s += K) + 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 (pos.is_chess960()) - { - Bitboard occ = pos.occupied_squares(); - clear_bit(&occ, rfrom); - if (pos.attackers_to(kto, occ) & enemies) - return mlist; - } - - (*mlist++).move = make_castle(kfrom, rfrom); - - if (OnlyChecks && !pos.move_gives_check((mlist - 1)->move, CheckInfo(pos))) - mlist--; - - return mlist; - } + if (Chess960 && (attacks_bb(kto, pos.pieces() ^ rfrom) & pos.pieces(~us, ROOK, QUEEN))) + return moveList; + Move m = make(kfrom, rfrom); - template - inline Bitboard move_pawns(Bitboard p) { + if (Checks && !pos.gives_check(m, *ci)) + return moveList; + else + (void)ci; // Silence a warning under MSVC - return Delta == DELTA_N ? p << 8 - : Delta == DELTA_S ? p >> 8 - : Delta == DELTA_NE ? (p & ~FileHBB) << 9 - : Delta == DELTA_SE ? (p & ~FileHBB) >> 7 - : Delta == DELTA_NW ? (p & ~FileABB) << 7 - : Delta == DELTA_SW ? (p & ~FileABB) >> 9 : 0; + *moveList++ = m; + return moveList; } - template - inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7, Bitboard target, Square ksq) { + template + ExtMove* make_promotions(ExtMove* moveList, Square to, const CheckInfo* ci) { - Bitboard b = move_pawns(pawnsOn7) & target; + if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS) + *moveList++ = make(to - Delta, to, QUEEN); - while (b) + if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS) { - Square to = pop_1st_bit(&b); - - if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION) - (*mlist++).move = make_promotion(to - Delta, to, QUEEN); - - if (Type == MV_QUIET || Type == MV_EVASION || Type == MV_NON_EVASION) - { - (*mlist++).move = make_promotion(to - Delta, to, ROOK); - (*mlist++).move = make_promotion(to - Delta, to, BISHOP); - (*mlist++).move = make_promotion(to - Delta, to, KNIGHT); - } - - // Knight-promotion is the only one that can give a direct check not - // already included in the queen-promotion. - if (Type == MV_QUIET_CHECK && bit_is_set(StepAttacksBB[W_KNIGHT][to], ksq)) - (*mlist++).move = make_promotion(to - Delta, to, KNIGHT); - else - (void)ksq; // Silence a warning under MSVC + *moveList++ = make(to - Delta, to, ROOK); + *moveList++ = make(to - Delta, to, BISHOP); + *moveList++ = make(to - Delta, to, KNIGHT); } - return mlist; + // 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++ = make(to - Delta, to, KNIGHT); + else + (void)ci; // Silence a warning under MSVC + + return moveList; } - template - MoveStack* generate_pawn_moves(const Position& pos, MoveStack* mlist, Bitboard target, Square ksq = SQ_NONE) { + template + ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, + Bitboard target, const CheckInfo* ci) { // Compute our parametrized parameters at compile time, named according to // the point of view of white side. @@ -140,77 +101,104 @@ namespace { 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); + 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); - Bitboard b1, b2, dc1, dc2, emptySquares; + Bitboard emptySquares; - Bitboard pawnsOn7 = pos.pieces(PAWN, Us) & TRank7BB; - Bitboard pawnsNotOn7 = pos.pieces(PAWN, Us) & ~TRank7BB; + Bitboard pawnsOn7 = pos.pieces(Us, PAWN) & TRank7BB; + Bitboard pawnsNotOn7 = pos.pieces(Us, PAWN) & ~TRank7BB; - Bitboard enemies = (Type == MV_EVASION ? pos.pieces(Them) & target: - Type == MV_CAPTURE ? target : pos.pieces(Them)); + Bitboard enemies = (Type == EVASIONS ? pos.pieces(Them) & target: + Type == CAPTURES ? target : pos.pieces(Them)); // Single and double pawn pushes, no promotions - if (Type != MV_CAPTURE) + if (Type != CAPTURES) { - emptySquares = (Type == MV_QUIET ? target : pos.empty_squares()); + emptySquares = (Type == QUIETS || Type == QUIET_CHECKS ? target : ~pos.pieces()); - b1 = move_pawns(pawnsNotOn7) & emptySquares; - b2 = move_pawns(b1 & TRank3BB) & emptySquares; + Bitboard b1 = shift_bb(pawnsNotOn7) & emptySquares; + Bitboard b2 = shift_bb(b1 & TRank3BB) & emptySquares; - if (Type == MV_EVASION) // Consider only blocking squares + if (Type == EVASIONS) // Consider only blocking squares { b1 &= target; b2 &= target; } - if (Type == MV_QUIET_CHECK) + if (Type == QUIET_CHECKS) { - b1 &= pos.attacks_from(ksq, Them); - b2 &= pos.attacks_from(ksq, Them); + b1 &= pos.attacks_from(ci->ksq, Them); + b2 &= pos.attacks_from(ci->ksq, Them); // 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 among captures. - if (pawnsNotOn7 & target) // Target is dc bitboard + // promotion has been already generated amongst the captures. + if (pawnsNotOn7 & ci->dcCandidates) { - dc1 = move_pawns(pawnsNotOn7 & target) & emptySquares & ~file_bb(ksq); - dc2 = move_pawns(dc1 & TRank3BB) & emptySquares; + Bitboard dc1 = shift_bb(pawnsNotOn7 & ci->dcCandidates) & emptySquares & ~file_bb(ci->ksq); + Bitboard dc2 = shift_bb(dc1 & TRank3BB) & emptySquares; b1 |= dc1; b2 |= dc2; } } - SERIALIZE_PAWNS(b1, UP); - SERIALIZE_PAWNS(b2, UP + UP); + while (b1) + { + Square to = pop_lsb(&b1); + *moveList++ = make_move(to - Up, to); + } + + while (b2) + { + Square to = pop_lsb(&b2); + *moveList++ = make_move(to - Up - Up, to); + } } // Promotions and underpromotions - if (pawnsOn7 && (Type != MV_EVASION || (target & TRank8BB))) + if (pawnsOn7 && (Type != EVASIONS || (target & TRank8BB))) { - if (Type == MV_CAPTURE) - emptySquares = pos.empty_squares(); + if (Type == CAPTURES) + emptySquares = ~pos.pieces(); - if (Type == MV_EVASION) + if (Type == EVASIONS) emptySquares &= target; - mlist = generate_promotions(mlist, pawnsOn7, enemies, ksq); - mlist = generate_promotions(mlist, pawnsOn7, enemies, ksq); - mlist = generate_promotions(mlist, pawnsOn7, emptySquares, ksq); + Bitboard b1 = shift_bb(pawnsOn7) & enemies; + Bitboard b2 = shift_bb(pawnsOn7) & enemies; + Bitboard b3 = shift_bb(pawnsOn7) & emptySquares; + + while (b1) + moveList = make_promotions(moveList, pop_lsb(&b1), ci); + + while (b2) + moveList = make_promotions(moveList, pop_lsb(&b2), ci); + + while (b3) + moveList = make_promotions(moveList, pop_lsb(&b3), ci); } // Standard and en-passant captures - if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION) + if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS) { - b1 = move_pawns(pawnsNotOn7) & enemies; - b2 = move_pawns(pawnsNotOn7) & enemies; + Bitboard b1 = shift_bb(pawnsNotOn7) & enemies; + Bitboard b2 = shift_bb(pawnsNotOn7) & enemies; + + while (b1) + { + Square to = pop_lsb(&b1); + *moveList++ = make_move(to - Right, to); + } - SERIALIZE_PAWNS(b1, RIGHT); - SERIALIZE_PAWNS(b2, LEFT); + while (b2) + { + Square to = pop_lsb(&b2); + *moveList++ = make_move(to - Left, to); + } if (pos.ep_square() != SQ_NONE) { @@ -219,143 +207,132 @@ namespace { // 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() - UP)) - return mlist; + if (Type == EVASIONS && !(target & (pos.ep_square() - Up))) + return moveList; b1 = pawnsNotOn7 & pos.attacks_from(pos.ep_square(), Them); assert(b1); while (b1) - (*mlist++).move = make_enpassant(pop_1st_bit(&b1), pos.ep_square()); + *moveList++ = make(pop_lsb(&b1), pos.ep_square()); } } - return mlist; + return moveList; } - template - inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, - Color us, const CheckInfo& ci) { + template + ExtMove* generate_moves(const Position& pos, ExtMove* moveList, Color us, + Bitboard target, const CheckInfo* ci) { + assert(Pt != KING && Pt != PAWN); - Bitboard b, target; - Square from; - const Square* pl = pos.piece_list(us, Pt); + const Square* pl = pos.squares(us); - if (*pl != SQ_NONE) + for (Square from = *pl; from != SQ_NONE; from = *++pl) { - target = ci.checkSq[Pt] & pos.empty_squares(); // Non capture checks only - - do { - from = *pl; - + if (Checks) + { if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN) - && !(PseudoAttacks[Pt][from] & target)) + && !(PseudoAttacks[Pt][from] & target & ci->checkSquares[Pt])) continue; - if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from)) + if (ci->dcCandidates && (ci->dcCandidates & from)) continue; + } + + Bitboard b = pos.attacks_from(from) & target; - b = pos.attacks_from(from) & target; - SERIALIZE(b); - } while (*++pl != SQ_NONE); + if (Checks) + b &= ci->checkSquares[Pt]; + + while (b) + *moveList++ = make_move(from, pop_lsb(&b)); } - return mlist; + return moveList; } - template - FORCE_INLINE MoveStack* generate_moves(const Position& pos, MoveStack* mlist, - Color us, Bitboard target) { - assert(Pt != KING && Pt != PAWN); + template + ExtMove* generate_all(const Position& pos, ExtMove* moveList, Bitboard target, + const CheckInfo* ci = nullptr) { - Bitboard b; - Square from; - const Square* pl = pos.piece_list(us, Pt); + const bool Checks = Type == QUIET_CHECKS; - if (*pl != SQ_NONE) - do { - from = *pl; - b = pos.attacks_from(from) & target; - SERIALIZE(b); - } while (*++pl != SQ_NONE); + 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); - return mlist; - } + if (Type != QUIET_CHECKS && Type != EVASIONS) + { + Square ksq = pos.square(Us); + Bitboard b = pos.attacks_from(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::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); + } + } - template<> - FORCE_INLINE MoveStack* generate_moves(const Position& pos, MoveStack* mlist, - Color us, Bitboard target) { - Square from = pos.king_square(us); - Bitboard b = pos.attacks_from(from) & target; - SERIALIZE(b); - return mlist; + return moveList; } } // namespace -/// generate 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 +/// 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 +/// generate generates all pseudo-legal captures and /// non-captures. Returns a pointer to the end of the move list. -template -MoveStack* generate(const Position& pos, MoveStack* mlist) { +template +ExtMove* generate(const Position& pos, ExtMove* moveList) { - assert(Type == MV_CAPTURE || Type == MV_QUIET || Type == MV_NON_EVASION); - assert(!pos.in_check()); + assert(Type == CAPTURES || Type == QUIETS || Type == NON_EVASIONS); + assert(!pos.checkers()); Color us = pos.side_to_move(); - Bitboard target; - - if (Type == MV_CAPTURE) - target = pos.pieces(~us); - - else if (Type == MV_QUIET) - target = pos.empty_squares(); - else if (Type == MV_NON_EVASION) - target = pos.pieces(~us) | pos.empty_squares(); + Bitboard target = Type == CAPTURES ? pos.pieces(~us) + : Type == QUIETS ? ~pos.pieces() + : Type == NON_EVASIONS ? ~pos.pieces(us) : 0; - mlist = (us == WHITE ? generate_pawn_moves(pos, mlist, target) - : generate_pawn_moves(pos, mlist, target)); - - mlist = generate_moves(pos, mlist, us, target); - mlist = generate_moves(pos, mlist, us, target); - mlist = generate_moves(pos, mlist, us, target); - mlist = generate_moves(pos, mlist, us, target); - mlist = generate_moves(pos, mlist, us, target); - - if (Type != MV_CAPTURE && pos.can_castle(us)) - { - mlist = generate_castle(pos, mlist, us); - mlist = generate_castle(pos, mlist, us); - } - - return mlist; + return us == WHITE ? generate_all(pos, moveList, target) + : generate_all(pos, moveList, target); } // 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); +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 and knight +/// generate 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) { +ExtMove* generate(const Position& pos, ExtMove* moveList) { - assert(!pos.in_check()); + assert(!pos.checkers()); Color us = pos.side_to_move(); CheckInfo ci(pos); @@ -363,124 +340,81 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { while (dc) { - Square from = pop_1st_bit(&dc); + Square from = pop_lsb(&dc); PieceType pt = type_of(pos.piece_on(from)); if (pt == PAWN) - continue; // Will be generated togheter with direct checks + continue; // Will be generated together with direct checks - Bitboard b = pos.attacks_from(Piece(pt), from) & pos.empty_squares(); + Bitboard b = pos.attacks_from(Piece(pt), from) & ~pos.pieces(); if (pt == KING) b &= ~PseudoAttacks[QUEEN][ci.ksq]; - SERIALIZE(b); + while (b) + *moveList++ = make_move(from, pop_lsb(&b)); } - mlist = (us == WHITE ? generate_pawn_moves(pos, mlist, ci.dcCandidates, ci.ksq) - : generate_pawn_moves(pos, mlist, ci.dcCandidates, ci.ksq)); - - mlist = generate_direct_checks(pos, mlist, us, ci); - mlist = generate_direct_checks(pos, mlist, us, ci); - mlist = generate_direct_checks(pos, mlist, us, ci); - mlist = generate_direct_checks(pos, mlist, us, ci); - - if (pos.can_castle(us)) - { - mlist = generate_castle(pos, mlist, us); - mlist = generate_castle(pos, mlist, us); - } - - return mlist; + return us == WHITE ? generate_all(pos, moveList, ~pos.pieces(), &ci) + : generate_all(pos, moveList, ~pos.pieces(), &ci); } -/// generate generates all pseudo-legal check evasions when the side +/// 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<> -MoveStack* generate(const Position& pos, MoveStack* mlist) { +ExtMove* generate(const Position& pos, ExtMove* moveList) { - assert(pos.in_check()); + assert(pos.checkers()); - Bitboard b, target; - Square from, checksq; - int checkersCnt = 0; Color us = pos.side_to_move(); - Square ksq = pos.king_square(us); + Square ksq = pos.square(us); Bitboard sliderAttacks = 0; - Bitboard checkers = pos.checkers(); + Bitboard sliders = pos.checkers() & ~pos.pieces(KNIGHT, PAWN); - assert(checkers); - - // Find squares attacked by slider checkers, we will remove them from the king - // evasions so to skip known illegal moves avoiding useless legality check later. - b = checkers; - do + // 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) { - checkersCnt++; - checksq = pop_1st_bit(&b); - - assert(color_of(pos.piece_on(checksq)) == ~us); - - switch (type_of(pos.piece_on(checksq))) - { - case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break; - case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break; - case QUEEN: - // If queen and king are far or not on a diagonal line we can safely - // remove all the squares attacked in the other direction becuase are - // not reachable by the king anyway. - if (squares_between(ksq, checksq) || !bit_is_set(PseudoAttacks[BISHOP][checksq], ksq)) - sliderAttacks |= PseudoAttacks[QUEEN][checksq]; - - // Otherwise we need to use real rook attacks to check if king is safe - // to move in the other direction. For example: king in B2, queen in A1 - // a knight in B1, and we can safely move to C1. - else - sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from(checksq); - - default: - break; - } - } while (b); + Square checksq = pop_lsb(&sliders); + sliderAttacks |= LineBB[checksq][ksq] ^ checksq; + } // Generate evasions for king, capture and non capture moves - b = pos.attacks_from(ksq) & ~pos.pieces(us) & ~sliderAttacks; - from = ksq; - SERIALIZE(b); + Bitboard b = pos.attacks_from(ksq) & ~pos.pieces(us) & ~sliderAttacks; + while (b) + *moveList++ = make_move(ksq, pop_lsb(&b)); - // Generate evasions for other pieces only if not under a double check - if (checkersCnt > 1) - return mlist; + if (more_than_one(pos.checkers())) + return moveList; // Double check, only a king move can save the day - // Blocking evasions or captures of the checking piece - target = squares_between(checksq, ksq) | checkers; + // Generate blocking evasions or captures of the checking piece + Square checksq = lsb(pos.checkers()); + Bitboard target = between_bb(checksq, ksq) | checksq; - mlist = (us == WHITE ? generate_pawn_moves(pos, mlist, target) - : generate_pawn_moves(pos, mlist, target)); - - mlist = generate_moves(pos, mlist, us, target); - mlist = generate_moves(pos, mlist, us, target); - mlist = generate_moves(pos, mlist, us, target); - return generate_moves(pos, mlist, us, target); + return us == WHITE ? generate_all(pos, moveList, target) + : generate_all(pos, moveList, target); } -/// generate generates all the legal moves in the given position +/// generate generates all the legal moves in the given position template<> -MoveStack* generate(const Position& pos, MoveStack* mlist) { - - MoveStack *last, *cur = mlist; - Bitboard pinned = pos.pinned_pieces(); - - last = pos.in_check() ? generate(pos, mlist) - : generate(pos, mlist); - while (cur != last) - if (!pos.pl_move_is_legal(cur->move, pinned)) - cur->move = (--last)->move; +ExtMove* generate(const Position& pos, ExtMove* moveList) { + + Bitboard pinned = pos.pinned_pieces(pos.side_to_move()); + Square ksq = pos.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) == ksq || type_of(*cur) == ENPASSANT) + && !pos.legal(*cur, pinned)) + *cur = (--moveList)->move; else - cur++; + ++cur; - return last; + return moveList; }