From: Marco Costalba Date: Wed, 13 Apr 2011 09:54:41 +0000 (+0200) Subject: Move move_is_legal() under Position class X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=54f1c383d36f461a740eeaa93856b408e8d3faa3 Move move_is_legal() under Position class It is a more logical place than in move generation file. No functional change. Signed-off-by: Marco Costalba --- diff --git a/src/movegen.cpp b/src/movegen.cpp index 0056ce38..64c6ac50 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -36,19 +36,19 @@ namespace { QUEEN_SIDE }; - template + template MoveStack* generate_castle_moves(const Position&, MoveStack*, Color us); - template + template MoveStack* generate_pawn_moves(const Position&, MoveStack*, Bitboard, Square); - template + template inline MoveStack* generate_discovered_checks(const Position& pos, MoveStack* mlist, Square from) { - assert(Piece != QUEEN); + assert(Pt != QUEEN); - Bitboard b = pos.attacks_from(from) & pos.empty_squares(); - if (Piece == KING) + Bitboard b = pos.attacks_from(from) & pos.empty_squares(); + if (Pt == KING) { Square ksq = pos.king_square(opposite_color(pos.side_to_move())); b &= ~QueenPseudoAttacks[ksq]; @@ -57,31 +57,31 @@ namespace { return mlist; } - template + template inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us, Bitboard dc, Square ksq) { - assert(Piece != KING); + assert(Pt != KING); Bitboard checkSqs, b; Square from; - const Square* ptr = pos.piece_list_begin(us, Piece); + const Square* ptr = pos.piece_list_begin(us, Pt); if ((from = *ptr++) == SQ_NONE) return mlist; - checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); + checkSqs = pos.attacks_from(ksq) & pos.empty_squares(); do { - if ( (Piece == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) - || (Piece == ROOK && !(RookPseudoAttacks[from] & checkSqs)) - || (Piece == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) + if ( (Pt == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) + || (Pt == ROOK && !(RookPseudoAttacks[from] & checkSqs)) + || (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) continue; if (dc && bit_is_set(dc, from)) continue; - b = pos.attacks_from(from) & checkSqs; + b = pos.attacks_from(from) & checkSqs; SERIALIZE_MOVES(b); } while ((from = *ptr++) != SQ_NONE); @@ -96,28 +96,28 @@ namespace { : generate_pawn_moves(p, m, dc, ksq)); } - template + template FORCE_INLINE MoveStack* generate_piece_moves(const Position& p, MoveStack* m, Color us, Bitboard t) { - assert(Piece == PAWN); + 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 + template FORCE_INLINE MoveStack* generate_piece_moves(const Position& pos, MoveStack* mlist, Color us, Bitboard target) { Bitboard b; Square from; - const Square* ptr = pos.piece_list_begin(us, Piece); + const Square* ptr = pos.piece_list_begin(us, Pt); if (*ptr != SQ_NONE) { do { from = *ptr; - b = pos.attacks_from(from) & target; + b = pos.attacks_from(from) & target; SERIALIZE_MOVES(b); } while (*++ptr != SQ_NONE); } @@ -137,10 +137,6 @@ namespace { } -//// -//// Functions -//// - /// generate generates all pseudo-legal captures and queen /// promotions. Returns a pointer to the end of the move list. @@ -194,7 +190,7 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { return mlist; } -// Explicit template instantiation +// 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); @@ -311,7 +307,7 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { /// generate computes a complete list of legal /// or pseudo-legal moves in the current position. template<> -inline MoveStack* generate(const Position& pos, MoveStack* mlist) { +MoveStack* generate(const Position& pos, MoveStack* mlist) { assert(pos.is_ok()); @@ -331,125 +327,15 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { // Remove illegal moves from the list while (cur != last) - if (pos.pl_move_is_legal(cur->move, pinned)) - cur++; - else + if (!pos.pl_move_is_legal(cur->move, pinned)) cur->move = (--last)->move; + else + cur++; return last; } -/// move_is_legal() takes a position and a (not necessarily pseudo-legal) -/// move and tests whether the move is legal. This version is not very fast -/// and should be used only in non time-critical paths. - -bool move_is_legal(const Position& pos, const Move m) { - - MoveStack mlist[MOVES_MAX]; - MoveStack *cur, *last = generate(pos, mlist); - - for (cur = mlist; cur != last; cur++) - if (cur->move == m) - return pos.pl_move_is_legal(m, pos.pinned_pieces(pos.side_to_move())); - - return false; -} - - -/// Fast version of move_is_legal() that takes a position a move and a -/// bitboard of pinned pieces as input, and tests whether the move is legal. - -bool move_is_legal(const Position& pos, const Move m, Bitboard pinned) { - - assert(pos.is_ok()); - assert(pinned == pos.pinned_pieces(pos.side_to_move())); - - Color us = pos.side_to_move(); - Color them = opposite_color(us); - Square from = move_from(m); - Square to = move_to(m); - Piece pc = pos.piece_on(from); - - // Use a slower but simpler function for uncommon cases - if (move_is_special(m)) - return move_is_legal(pos, m); - - // If the from square is not occupied by a piece belonging to the side to - // move, the move is obviously not legal. - if (color_of_piece(pc) != us) - return false; - - // The destination square cannot be occupied by a friendly piece - if (pos.color_of_piece_on(to) == us) - return false; - - // Handle the special case of a pawn move - if (type_of_piece(pc) == PAWN) - { - // Move direction must be compatible with pawn color - int direction = to - from; - if ((us == WHITE) != (direction > 0)) - return false; - - // We have already handled promotion moves, so destination - // cannot be on the 8/1th rank. - if (square_rank(to) == RANK_8 || square_rank(to) == RANK_1) - return false; - - // Proceed according to the square delta between the origin and - // destination squares. - switch (direction) - { - case DELTA_NW: - case DELTA_NE: - case DELTA_SW: - case DELTA_SE: - // Capture. The destination square must be occupied by an enemy - // piece (en passant captures was handled earlier). - if (pos.color_of_piece_on(to) != them) - return false; - break; - - case DELTA_N: - case DELTA_S: - // Pawn push. The destination square must be empty. - if (!pos.square_is_empty(to)) - return false; - break; - - case DELTA_NN: - // Double white pawn push. The destination square must be on the fourth - // rank, and both the destination square and the square between the - // source and destination squares must be empty. - if ( square_rank(to) != RANK_4 - || !pos.square_is_empty(to) - || !pos.square_is_empty(from + DELTA_N)) - return false; - break; - - case DELTA_SS: - // Double black pawn push. The destination square must be on the fifth - // rank, and both the destination square and the square between the - // source and destination squares must be empty. - if ( square_rank(to) != RANK_5 - || !pos.square_is_empty(to) - || !pos.square_is_empty(from + DELTA_S)) - return false; - break; - - default: - return false; - } - } - else if (!bit_is_set(pos.attacks_from(pc, from), to)) - return false; - - // The move is pseudo-legal, check if it is also legal - return pos.is_check() ? pos.pl_move_is_evasion(m, pinned) : pos.pl_move_is_legal(m, pinned); -} - - namespace { template diff --git a/src/movegen.h b/src/movegen.h index 4bb44331..f14558e7 100644 --- a/src/movegen.h +++ b/src/movegen.h @@ -36,7 +36,4 @@ enum MoveType { template MoveStack* generate(const Position& pos, MoveStack* mlist); -extern bool move_is_legal(const Position& pos, const Move m, Bitboard pinned); -extern bool move_is_legal(const Position& pos, const Move m); - #endif // !defined(MOVEGEN_H_INCLUDED) diff --git a/src/movepick.cpp b/src/movepick.cpp index 3bc85556..4bdfd374 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -280,7 +280,7 @@ Move MovePicker::get_next_move() { case PH_TT_MOVES: move = (curMove++)->move; if ( move != MOVE_NONE - && move_is_legal(pos, move, pinned)) + && pos.move_is_legal(move, pinned)) return move; break; @@ -305,7 +305,7 @@ Move MovePicker::get_next_move() { case PH_KILLERS: move = (curMove++)->move; if ( move != MOVE_NONE - && move_is_legal(pos, move, pinned) + && pos.move_is_legal(move, pinned) && move != ttMoves[0].move && move != ttMoves[1].move && !pos.move_is_capture(move)) diff --git a/src/position.cpp b/src/position.cpp index abe7fde3..e3bf4aee 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -643,6 +643,115 @@ bool Position::pl_move_is_evasion(Move m, Bitboard pinned) const return bit_is_set(target, to) && pl_move_is_legal(m, pinned); } +/// Position::move_is_legal() takes a position and a (not necessarily pseudo-legal) +/// move and tests whether the move is legal. This version is not very fast and +/// should be used only in non time-critical paths. + +bool Position::move_is_legal(const Move m) const { + + MoveStack mlist[MOVES_MAX]; + MoveStack *cur, *last = generate(*this, mlist); + + for (cur = mlist; cur != last; cur++) + if (cur->move == m) + return pl_move_is_legal(m, pinned_pieces(sideToMove)); + + return false; +} + + +/// Fast version of Position::move_is_legal() that takes a position a move and +/// a bitboard of pinned pieces as input, and tests whether the move is legal. + +bool Position::move_is_legal(const Move m, Bitboard pinned) const { + + assert(is_ok()); + assert(pinned == pinned_pieces(sideToMove)); + + Color us = sideToMove; + Color them = opposite_color(sideToMove); + Square from = move_from(m); + Square to = move_to(m); + Piece pc = piece_on(from); + + // Use a slower but simpler function for uncommon cases + if (move_is_special(m)) + return move_is_legal(m); + + // If the from square is not occupied by a piece belonging to the side to + // move, the move is obviously not legal. + if (color_of_piece(pc) != us) + return false; + + // The destination square cannot be occupied by a friendly piece + if (color_of_piece_on(to) == us) + return false; + + // Handle the special case of a pawn move + if (type_of_piece(pc) == PAWN) + { + // Move direction must be compatible with pawn color + int direction = to - from; + if ((us == WHITE) != (direction > 0)) + return false; + + // We have already handled promotion moves, so destination + // cannot be on the 8/1th rank. + if (square_rank(to) == RANK_8 || square_rank(to) == RANK_1) + return false; + + // Proceed according to the square delta between the origin and + // destination squares. + switch (direction) + { + case DELTA_NW: + case DELTA_NE: + case DELTA_SW: + case DELTA_SE: + // Capture. The destination square must be occupied by an enemy + // piece (en passant captures was handled earlier). + if (color_of_piece_on(to) != them) + return false; + break; + + case DELTA_N: + case DELTA_S: + // Pawn push. The destination square must be empty. + if (!square_is_empty(to)) + return false; + break; + + case DELTA_NN: + // Double white pawn push. The destination square must be on the fourth + // rank, and both the destination square and the square between the + // source and destination squares must be empty. + if ( square_rank(to) != RANK_4 + || !square_is_empty(to) + || !square_is_empty(from + DELTA_N)) + return false; + break; + + case DELTA_SS: + // Double black pawn push. The destination square must be on the fifth + // rank, and both the destination square and the square between the + // source and destination squares must be empty. + if ( square_rank(to) != RANK_5 + || !square_is_empty(to) + || !square_is_empty(from + DELTA_S)) + return false; + break; + + default: + return false; + } + } + else if (!bit_is_set(attacks_from(pc, from), to)) + return false; + + // The move is pseudo-legal, check if it is also legal + return is_check() ? pl_move_is_evasion(m, pinned) : pl_move_is_legal(m, pinned); +} + /// Position::move_is_check() tests whether a pseudo-legal move is a check diff --git a/src/position.h b/src/position.h index c0c7e929..222cd92c 100644 --- a/src/position.h +++ b/src/position.h @@ -184,6 +184,8 @@ public: // Properties of moves bool pl_move_is_legal(Move m, Bitboard pinned) const; bool pl_move_is_evasion(Move m, Bitboard pinned) const; + bool move_is_legal(const Move m) const; + bool move_is_legal(const Move m, Bitboard pinned) const; bool move_is_check(Move m) const; bool move_is_check(Move m, const CheckInfo& ci) const; bool move_is_capture(Move m) const; diff --git a/src/search.cpp b/src/search.cpp index 80aa55cb..07700c6c 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -2442,13 +2442,13 @@ split_point_start: // At split points actual search starts from here TTEntry* tte; int ply = 1; - assert(pv[0] != MOVE_NONE && move_is_legal(pos, pv[0])); + assert(pv[0] != MOVE_NONE && pos.move_is_legal(pv[0])); pos.do_move(pv[0], *st++); while ( (tte = TT.retrieve(pos.get_key())) != NULL && tte->move() != MOVE_NONE - && move_is_legal(pos, tte->move()) + && pos.move_is_legal(tte->move()) && ply < PLY_MAX && (!pos.is_draw() || ply < 2)) { @@ -2472,7 +2472,7 @@ split_point_start: // At split points actual search starts from here Value v, m = VALUE_NONE; int ply = 0; - assert(pv[0] != MOVE_NONE && move_is_legal(pos, pv[0])); + assert(pv[0] != MOVE_NONE && pos.move_is_legal(pv[0])); do { k = pos.get_key();