X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovegen.cpp;h=7cbd157a75b5a008e6d0f92ae8bfc93f2fcf8366;hp=1f9c17a80a20188175eb445888ef627f7f1e919b;hb=d655147e8c;hpb=8307da0de77c9c7bbf7c56a7d9c8a688ff4dfb4e diff --git a/src/movegen.cpp b/src/movegen.cpp index 1f9c17a8..7cbd157a 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -23,6 +23,7 @@ #include "bitcount.h" #include "movegen.h" #include "position.h" +#include "misc.h" // Simple macro to wrap a very common while loop, no facny, no flexibility, // hardcoded list name 'mlist' and from square 'from'. @@ -33,31 +34,224 @@ namespace { - enum CastlingSide { - KING_SIDE, - QUEEN_SIDE - }; + enum CastlingSide { KING_SIDE, QUEEN_SIDE }; - template - MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us); + template + MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) { - template - MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square); + const CastleRight CR[] = { Side ? WHITE_OOO : WHITE_OO, + Side ? BLACK_OOO : BLACK_OO }; - template - inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) { + if (!pos.can_castle(CR[us])) + return mlist; - assert(Pt != QUEEN && Pt != PAWN); + // 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); + Bitboard enemies = pos.pieces(flip(us)); - Bitboard b = pos.attacks_from(from) & pos.empty_squares(); + assert(!pos.in_check()); + assert(pos.piece_on(kfrom) == make_piece(us, KING)); + assert(pos.piece_on(rfrom) == make_piece(us, ROOK)); - if (Pt == KING) - b &= ~QueenPseudoAttacks[pos.king_square(flip(pos.side_to_move()))]; + // 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; - SERIALIZE_MOVES(b); + 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; + + // 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); + + return mlist; + } + + + template + inline Bitboard move_pawns(Bitboard p) { + + 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; + } + + + template + inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) { + + const Bitboard TFileABB = ( Delta == DELTA_NE + || Delta == DELTA_SE ? FileABB : FileHBB); + Bitboard b; + Square to; + + b = move_pawns(pawns) & target & ~TFileABB; + SERIALIZE_MOVES_D(b, -Delta); + return mlist; + } + + + template + inline MoveStack* generate_promotions(MoveStack* mlist, Bitboard pawnsOn7, Bitboard target, Square ksq) { + + const Bitboard TFileABB = ( Delta == DELTA_NE + || Delta == DELTA_SE ? FileABB : FileHBB); + Bitboard b; + Square to; + + b = move_pawns(pawnsOn7) & target; + + if (Delta != DELTA_N && Delta != DELTA_S) + b &= ~TFileABB; + + while (b) + { + 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_NON_CAPTURE || 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 check (direct or + // discovered) not already included in the queen-promotion. + if ( Type == MV_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 + } return mlist; } + + 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 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); + + Square to; + Bitboard b1, b2, dc1, dc2, emptySquares; + + Bitboard pawns = pos.pieces(PAWN, Us); + Bitboard pawnsOn7 = pawns & TRank7BB; + Bitboard pawnsNotOn7 = pawns & ~TRank7BB; + + Bitboard enemies = (Type == MV_EVASION ? pos.pieces(Them) & target: + Type == MV_CAPTURE ? target : pos.pieces(Them)); + + // Single and double pawn pushes, no promotions + if (Type != MV_CAPTURE) + { + emptySquares = (Type == MV_NON_CAPTURE ? target : pos.empty_squares()); + + b1 = move_pawns(pawnsNotOn7) & emptySquares; + b2 = move_pawns(b1 & TRank3BB) & emptySquares; + + if (Type == MV_EVASION) + { + b1 &= target; // Consider only blocking squares + b2 &= target; + } + + if (Type == MV_CHECK) + { + // Consider only direct checks + b1 &= pos.attacks_from(ksq, Them); + b2 &= pos.attacks_from(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) // For CHECK type target is dc bitboard + { + dc1 = move_pawns(pawnsNotOn7 & target) & emptySquares & ~file_bb(ksq); + dc2 = move_pawns(dc1 & TRank3BB) & emptySquares; + + b1 |= dc1; + b2 |= dc2; + } + } + + SERIALIZE_MOVES_D(b1, -UP); + SERIALIZE_MOVES_D(b2, -UP -UP); + } + + // Promotions and underpromotions + if (pawnsOn7) + { + if (Type == MV_CAPTURE) + emptySquares = pos.empty_squares(); + + if (Type == MV_EVASION) + emptySquares &= target; + + mlist = generate_promotions(mlist, pawnsOn7, enemies, ksq); + mlist = generate_promotions(mlist, pawnsOn7, enemies, ksq); + mlist = generate_promotions(mlist, pawnsOn7, emptySquares, ksq); + } + + // Standard and en-passant captures + if (Type == MV_CAPTURE || Type == MV_EVASION || Type == MV_NON_EVASION) + { + mlist = generate_pawn_captures(mlist, pawnsNotOn7, enemies); + mlist = generate_pawn_captures(mlist, pawnsNotOn7, enemies); + + if (pos.ep_square() != SQ_NONE) + { + assert(rank_of(pos.ep_square()) == (Us == WHITE ? RANK_6 : RANK_3)); + + // 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; + + b1 = pawnsNotOn7 & pos.attacks_from(pos.ep_square(), Them); + + assert(b1); + + while (b1) + (*mlist++).move = make_enpassant(pop_1st_bit(&b1), pos.ep_square()); + } + } + + return mlist; + } + + template inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us, Bitboard dc, Square ksq) { @@ -90,6 +284,7 @@ namespace { return mlist; } + template<> FORCE_INLINE MoveStack* generate_direct_checks(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) { @@ -97,16 +292,16 @@ namespace { : generate_pawn_moves(p, m, dc, ksq)); } + 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) { @@ -125,6 +320,7 @@ namespace { return mlist; } + template<> FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { @@ -136,7 +332,7 @@ namespace { return mlist; } -} +} // namespace /// generate generates all pseudo-legal captures and queen @@ -151,27 +347,22 @@ namespace { template MoveStack* generate(const Position& pos, MoveStack* mlist) { + assert(Type == MV_CAPTURE || Type == MV_NON_CAPTURE || Type == MV_NON_EVASION); assert(!pos.in_check()); Color us = pos.side_to_move(); Bitboard target; - if (Type == MV_CAPTURE || Type == MV_NON_EVASION) + if (Type == MV_CAPTURE) target = pos.pieces(flip(us)); + else if (Type == MV_NON_CAPTURE) target = pos.empty_squares(); - else - assert(false); - 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); + else if (Type == MV_NON_EVASION) + target = pos.pieces(flip(us)) | pos.empty_squares(); + 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); @@ -180,11 +371,8 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { if (Type != MV_CAPTURE && pos.can_castle(us)) { - if (pos.can_castle(us == WHITE ? WHITE_OO : BLACK_OO)) - mlist = generate_castle_moves(pos, mlist, us); - - if (pos.can_castle(us == WHITE ? WHITE_OOO : BLACK_OOO)) - mlist = generate_castle_moves(pos, mlist, us); + mlist = generate_castle_moves(pos, mlist, us); + mlist = generate_castle_moves(pos, mlist, us); } return mlist; @@ -205,6 +393,7 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) Bitboard b, dc; Square from; + PieceType pt; Color us = pos.side_to_move(); Square ksq = pos.king_square(flip(us)); @@ -216,15 +405,17 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) while (b) { from = pop_1st_bit(&b); - switch (type_of(pos.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; - } + pt = type_of(pos.piece_on(from)); + + if (pt == PAWN) + continue; // Will be generated togheter with direct checks + + b = pos.attacks_from(Piece(pt), from) & pos.empty_squares(); + + if (pt == KING) + b &= ~QueenPseudoAttacks[ksq]; + + SERIALIZE_MOVES(b); } // Direct non-capture checks @@ -327,217 +518,3 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { return last; } - - -namespace { - - template - inline Bitboard move_pawns(Bitboard p) { - - 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; - } - - template - inline MoveStack* generate_pawn_captures(MoveStack* mlist, Bitboard pawns, Bitboard target) { - - const Bitboard TFileABB = (Delta == DELTA_NE || Delta == DELTA_SE ? FileABB : FileHBB); - - Bitboard b; - Square to; - - // 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; - } - - 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); - - Bitboard b; - Square to; - - // Promotions and under-promotions, both captures and non-captures - b = move_pawns(pawnsOn7) & target; - - if (Delta != DELTA_N && Delta != DELTA_S) - b &= ~TFileABB; - - while (b) - { - to = pop_1st_bit(&b); - - if (Type == MV_CAPTURE || Type == MV_EVASION) - (*mlist++).move = make_promotion_move(to - Delta, to, QUEEN); - - 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); - } - - // 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(Delta > 0 ? BLACK : WHITE))) - (*mlist++).move = make_promotion_move(to - Delta, to, KNIGHT); - else (void)pos; // Silence a warning under MSVC - } - return mlist; - } - - 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 UP = (Us == WHITE ? DELTA_N : DELTA_S); - const Square RIGHT_UP = (Us == WHITE ? DELTA_NE : DELTA_SW); - const Square LEFT_UP = (Us == WHITE ? DELTA_NW : DELTA_SE); - - 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(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; - } - - 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(); - - pawns &= ~TRank7BB; - mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces); - mlist = generate_promotions(pos, mlist, pawnsOn7, enemyPieces); - mlist = generate_promotions(pos, mlist, pawnsOn7, emptySquares); - } - - // Standard captures - if (Type == MV_CAPTURE || Type == MV_EVASION) - { - mlist = generate_pawn_captures(mlist, pawns, enemyPieces); - mlist = generate_pawn_captures(mlist, pawns, enemyPieces); - } - - // Single and double pawn pushes - if (Type != MV_CAPTURE) - { - b1 = (Type != MV_EVASION ? pawnPushes : pawnPushes & emptySquares); - b2 = move_pawns(pawnPushes & TRank3BB) & emptySquares; - - if (Type == MV_CHECK) - { - // Consider only pawn moves which give direct checks - b1 &= pos.attacks_from(ksq, Them); - b2 &= pos.attacks_from(ksq, Them); - - // 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; - - b1 |= dc1; - b2 |= dc2; - } - } - SERIALIZE_MOVES_D(b1, -UP); - SERIALIZE_MOVES_D(b2, -UP -UP); - } - - // En passant captures - if ((Type == MV_CAPTURE || Type == MV_EVASION) && pos.ep_square() != SQ_NONE) - { - assert(Us != WHITE || rank_of(pos.ep_square()) == RANK_6); - assert(Us != BLACK || rank_of(pos.ep_square()) == RANK_3); - - // 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; - - b1 = pawns & pos.attacks_from(pos.ep_square(), Them); - - assert(b1); - - while (b1) - { - to = pop_1st_bit(&b1); - (*mlist++).move = make_enpassant_move(to, pos.ep_square()); - } - } - return mlist; - } - - template - MoveStack* generate_castle_moves(const Position& pos, MoveStack* mlist, Color us) { - - CastleRight f = CastleRight((Side == KING_SIDE ? WHITE_OO : WHITE_OOO) << us); - Color them = flip(us); - - // After castling, the rook and king's final positions are exactly the same - // in Chess960 as they would be in standard chess. - Square kfrom = pos.king_square(us); - Square rfrom = pos.castle_rook_square(f); - Square kto = relative_square(us, Side == KING_SIDE ? SQ_G1 : SQ_C1); - Square rto = relative_square(us, Side == KING_SIDE ? SQ_F1 : SQ_D1); - - assert(!pos.in_check()); - assert(pos.piece_on(kfrom) == make_piece(us, KING)); - assert(pos.piece_on(rfrom) == make_piece(us, ROOK)); - - // 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(kfrom, kto); s <= std::max(kfrom, kto); s++) - if ( (s != kfrom && s != rfrom && !pos.square_is_empty(s)) - ||(pos.attackers_to(s) & pos.pieces(them))) - return mlist; - - for (Square s = std::min(rfrom, rto); s <= std::max(rfrom, rto); s++) - if (s != kfrom && s != rfrom && !pos.square_is_empty(s)) - return mlist; - - // 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) & pos.pieces(them)) - return mlist; - } - - (*mlist++).move = make_castle_move(kfrom, rfrom); - - return mlist; - } - -} // namespace