X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=5e1ebfeb486880de58081900499f67cd2b4f55b3;hp=67ee145c11efecb3500a26843db96ff1acf9c354;hb=c97104e8540b72ee2c6c9c13d3773d2c0f9ec32f;hpb=a5c1b3e8f68a9c98e6be1f90e7d0295d05c685de diff --git a/src/position.cpp b/src/position.cpp index 67ee145c..5e1ebfeb 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -31,6 +31,7 @@ #include "movepick.h" #include "position.h" #include "psqtab.h" +#include "san.h" #include "ucioption.h" @@ -38,6 +39,8 @@ //// Variables //// +extern SearchStack EmptySearchStack; + int Position::castleRightsMask[64]; Key Position::zobrist[2][8][64]; @@ -49,6 +52,7 @@ Key Position::zobSideToMove; Value Position::MgPieceSquareTable[16][64]; Value Position::EgPieceSquareTable[16][64]; +static bool RequestPending = false; //// //// Functions @@ -242,7 +246,7 @@ const std::string Position::to_fen() const { fen += (rank > RANK_1 ? '/' : ' '); } - fen += (sideToMove == WHITE ? 'w' : 'b') + ' '; + fen += (sideToMove == WHITE ? "w " : "b "); if (castleRights != NO_CASTLES) { if (can_castle_kingside(WHITE)) fen += 'K'; @@ -263,29 +267,45 @@ const std::string Position::to_fen() const { /// Position::print() prints an ASCII representation of the position to -/// the standard output. - -void Position::print() const { - char pieceStrings[][8] = - {"| ? ", "| P ", "| N ", "| B ", "| R ", "| Q ", "| K ", "| ? ", - "| ? ", "|=P=", "|=N=", "|=B=", "|=R=", "|=Q=", "|=K=" - }; - - for(Rank rank = RANK_8; rank >= RANK_1; rank--) { - std::cout << "+---+---+---+---+---+---+---+---+\n"; - for(File file = FILE_A; file <= FILE_H; file++) { - Square sq = make_square(file, rank); - Piece piece = piece_on(sq); - if(piece == EMPTY) - std::cout << ((square_color(sq) == WHITE)? "| " : "| . "); - else - std::cout << pieceStrings[piece]; - } - std::cout << "|\n"; +/// the standard output. If a move is given then also the san is print. + +void Position::print(Move m) const { + + static const std::string pieceLetters = " PNBRQK PNBRQK ."; + + // Check for reentrancy, as example when called from inside + // MovePicker that is used also here in move_to_san() + if (RequestPending) + return; + + RequestPending = true; + + std::cout << std::endl; + if (m != MOVE_NONE) + { + std::string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : ""); + std::cout << "Move is: " << col << move_to_san(*this, m) << std::endl; + } + for (Rank rank = RANK_8; rank >= RANK_1; rank--) + { + std::cout << "+---+---+---+---+---+---+---+---+" << std::endl; + for (File file = FILE_A; file <= FILE_H; file++) + { + Square sq = make_square(file, rank); + Piece piece = piece_on(sq); + if (piece == EMPTY && square_color(sq) == WHITE) + piece = NO_PIECE; + + char col = (color_of_piece_on(sq) == BLACK ? '=' : ' '); + std::cout << '|' << col << pieceLetters[piece] << col; + } + std::cout << '|' << std::endl; } - std::cout << "+---+---+---+---+---+---+---+---+\n"; - std::cout << to_fen() << std::endl; - std::cout << key << std::endl; + std::cout << "+---+---+---+---+---+---+---+---+" << std::endl + << "Fen is: " << to_fen() << std::endl + << "Key is: " << key << std::endl; + + RequestPending = false; } @@ -410,6 +430,7 @@ bool Position::piece_attacks_square(Square f, Square t) const { case WR: case BR: return piece_attacks_square(f, t); case WQ: case BQ: return piece_attacks_square(f, t); case WK: case BK: return piece_attacks_square(f, t); + default: break; } return false; } @@ -437,7 +458,7 @@ bool Position::move_attacks_square(Move m, Square s) const { case WR: case BR: return piece_attacks_square(t, s); case WQ: case BQ: return piece_attacks_square(t, s); case WK: case BK: return piece_attacks_square(t, s); - default: assert(false); + default: break; } return false; } @@ -446,12 +467,13 @@ bool Position::move_attacks_square(Move m, Square s) const { /// Position::find_checkers() computes the checkersBB bitboard, which /// contains a nonzero bit for each checking piece (0, 1 or 2). It /// currently works by calling Position::attacks_to, which is probably -/// inefficient. Consider rewriting this function to use the last move +/// inefficient. Consider rewriting this function to use the last move /// played, like in non-bitboard versions of Glaurung. void Position::find_checkers() { - checkersBB = attacks_to(king_square(side_to_move()),opposite_color(side_to_move())); + Color us = side_to_move(); + checkersBB = attacks_to(king_square(us), opposite_color(us)); } @@ -468,9 +490,6 @@ bool Position::pl_move_is_legal(Move m) const { bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { - Color us, them; - Square ksq, from; - assert(is_ok()); assert(move_is_ok(m)); assert(pinned == pinned_pieces(side_to_move())); @@ -484,10 +503,10 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { if (move_is_castle(m)) return true; - us = side_to_move(); - them = opposite_color(us); - from = move_from(m); - ksq = king_square(us); + Color us = side_to_move(); + Color them = opposite_color(us); + Square from = move_from(m); + Square ksq = king_square(us); assert(color_of_piece_on(from) == us); assert(piece_on(ksq) == king_of_color(us)); @@ -521,11 +540,8 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { // A non-king move is legal if and only if it is not pinned or it // is moving along the ray towards or away from the king. - if ( !bit_is_set(pinned, from) - || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq))) - return true; - - return false; + return ( !bit_is_set(pinned, from) + || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq))); } @@ -543,18 +559,15 @@ bool Position::move_is_check(Move m) const { bool Position::move_is_check(Move m, Bitboard dcCandidates) const { - Color us, them; - Square ksq, from, to; - assert(is_ok()); assert(move_is_ok(m)); assert(dcCandidates == discovered_check_candidates(side_to_move())); - us = side_to_move(); - them = opposite_color(us); - from = move_from(m); - to = move_to(m); - ksq = king_square(them); + Color us = side_to_move(); + Color them = opposite_color(us); + Square from = move_from(m); + Square to = move_to(m); + Square ksq = king_square(them); assert(color_of_piece_on(from) == us); assert(piece_on(ksq) == king_of_color(them)); @@ -653,8 +666,8 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { } return false; - default: - assert(false); + default: // NO_PIECE_TYPE + break; } assert(false); return false; @@ -662,12 +675,16 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { /// Position::move_is_capture() tests whether a move from the current -/// position is a capture. +/// position is a capture. Move must not be MOVE_NONE. bool Position::move_is_capture(Move m) const { - return color_of_piece_on(move_to(m)) == opposite_color(side_to_move()) - || move_is_ep(m); + assert(m != MOVE_NONE); + + return ( !square_is_empty(move_to(m)) + && (color_of_piece_on(move_to(m)) == opposite_color(side_to_move())) + ) + || move_is_ep(m); } @@ -681,16 +698,16 @@ bool Position::move_is_capture(Move m) const { void Position::backup(UndoInfo& u) const { u.castleRights = castleRights; - u.epSquare = epSquare; - u.checkersBB = checkersBB; - u.key = key; - u.pawnKey = pawnKey; - u.materialKey = materialKey; - u.rule50 = rule50; - u.lastMove = lastMove; - u.capture = NO_PIECE_TYPE; - u.mgValue = mgValue; - u.egValue = egValue; + u.epSquare = epSquare; + u.checkersBB = checkersBB; + u.key = key; + u.pawnKey = pawnKey; + u.materialKey = materialKey; + u.rule50 = rule50; + u.lastMove = lastMove; + u.mgValue = mgValue; + u.egValue = egValue; + u.capture = NO_PIECE_TYPE; } @@ -700,25 +717,24 @@ void Position::backup(UndoInfo& u) const { void Position::restore(const UndoInfo& u) { castleRights = u.castleRights; - epSquare = u.epSquare; - checkersBB = u.checkersBB; - key = u.key; - pawnKey = u.pawnKey; - materialKey = u.materialKey; - rule50 = u.rule50; - lastMove = u.lastMove; + epSquare = u.epSquare; + checkersBB = u.checkersBB; + key = u.key; + pawnKey = u.pawnKey; + materialKey = u.materialKey; + rule50 = u.rule50; + lastMove = u.lastMove; + mgValue = u.mgValue; + egValue = u.egValue; // u.capture is restored in undo_move() - mgValue = u.mgValue; - egValue = u.egValue; } - /// Position::do_move() makes a move, and backs up all information necessary -/// to undo the move to an UndoInfo object. The move is assumed to be legal. +/// to undo the move to an UndoInfo object. The move is assumed to be legal. /// Pseudo-legal moves should be filtered out before this function is called. /// There are two versions of this function, one which takes only the move and /// the UndoInfo as input, and one which takes a third parameter, a bitboard of -/// discovered check candidates. The second version is faster, because knowing +/// discovered check candidates. The second version is faster, because knowing /// the discovered check candidates makes it easier to update the checkersBB /// member variable in the position object. @@ -765,42 +781,8 @@ void Position::do_move(Move m, UndoInfo& u, Bitboard dcCandidates) { if (capture) { - assert(capture != KING); - - // Remove captured piece - clear_bit(&(byColorBB[them]), to); - clear_bit(&(byTypeBB[capture]), to); - - // Update hash key - key ^= zobrist[them][capture][to]; - - // If the captured piece was a pawn, update pawn hash key - if (capture == PAWN) - pawnKey ^= zobrist[them][PAWN][to]; - - // Update incremental scores - mgValue -= mg_pst(them, capture, to); - egValue -= eg_pst(them, capture, to); - - // Update material - if (capture != PAWN) - npMaterial[them] -= piece_value_midgame(capture); - - // Update material hash key - materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]]; - - // Update piece count - pieceCount[them][capture]--; - - // Update piece list - pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]]; - index[pieceList[them][capture][index[to]]] = index[to]; - - // Remember the captured piece, in order to be able to undo the move correctly - u.capture = capture; - - // Reset rule 50 counter - rule50 = 0; + u.capture = capture; + do_capture_move(m, capture, them, to); } // Move the piece @@ -931,8 +913,51 @@ void Position::do_move(Move m, UndoInfo& u, Bitboard dcCandidates) { } +/// Position::do_capture_move() is a private method used to update captured +/// piece info. It is called from the main Position::do_move function. + +void Position::do_capture_move(Move m, PieceType capture, Color them, Square to) { + + assert(capture != KING); + + // Remove captured piece + clear_bit(&(byColorBB[them]), to); + clear_bit(&(byTypeBB[capture]), to); + + // Update hash key + key ^= zobrist[them][capture][to]; + + // If the captured piece was a pawn, update pawn hash key + if (capture == PAWN) + pawnKey ^= zobrist[them][PAWN][to]; + + // Update incremental scores + mgValue -= mg_pst(them, capture, to); + egValue -= eg_pst(them, capture, to); + + assert(!move_promotion(m) || capture != PAWN); + + // Update material + if (capture != PAWN) + npMaterial[them] -= piece_value_midgame(capture); + + // Update material hash key + materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]]; + + // Update piece count + pieceCount[them][capture]--; + + // Update piece list + pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]]; + index[pieceList[them][capture][index[to]]] = index[to]; + + // Reset rule 50 counter + rule50 = 0; +} + + /// Position::do_castle_move() is a private method used to make a castling -/// move. It is called from the main Position::do_move function. Note that +/// move. It is called from the main Position::do_move function. Note that /// castling moves are encoded as "king captures friendly rook" moves, for /// instance white short castling in a non-Chess960 game is encoded as e1h1. @@ -1056,36 +1081,8 @@ void Position::do_promotion_move(Move m, UndoInfo &u) { if (capture) { - assert(capture != KING); - - // Remove captured piece - clear_bit(&(byColorBB[them]), to); - clear_bit(&(byTypeBB[capture]), to); - - // Update hash key - key ^= zobrist[them][capture][to]; - - // Update incremental scores - mgValue -= mg_pst(them, capture, to); - egValue -= eg_pst(them, capture, to); - - // Update material. Because our move is a promotion, we know that the - // captured piece is not a pawn. - assert(capture != PAWN); - npMaterial[them] -= piece_value_midgame(capture); - - // Update material hash key - materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]]; - - // Update piece count - pieceCount[them][capture]--; - - // Update piece list - pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]]; - index[pieceList[them][capture][index[to]]] = index[to]; - - // Remember the captured piece, in order to be able to undo the move correctly u.capture = capture; + do_capture_move(m, capture, them, to); } // Remove pawn @@ -1585,10 +1582,16 @@ void Position::undo_null_move(const UndoInfo &u) { /// Position::see() is a static exchange evaluator: It tries to estimate the -/// material gain or loss resulting from a move. There are two versions of -/// this function: One which takes a move as input, and one which takes a -/// 'from' and a 'to' square. The function does not yet understand promotions -/// or en passant captures. +/// material gain or loss resulting from a move. There are three versions of +/// this function: One which takes a destination square as input, one takes a +/// move, and one which takes a 'from' and a 'to' square. The function does +/// not yet understand promotions or en passant captures. + +int Position::see(Square to) const { + + assert(square_is_ok(to)); + return see(SQ_NONE, to); +} int Position::see(Move m) const { @@ -1598,18 +1601,22 @@ int Position::see(Move m) const { int Position::see(Square from, Square to) const { - // Approximate material values, with pawn = 1 + // Material values static const int seeValues[18] = { - 0, 1, 3, 3, 5, 10, 100, 0, 0, 1, 3, 3, 5, 10, 100, 0, 0, 0 + 0, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, + RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10, 0, + 0, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, + RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10, 0, + 0, 0 }; Bitboard attackers, occ, b; - assert(square_is_ok(from)); + assert(square_is_ok(from) || from == SQ_NONE); assert(square_is_ok(to)); // Initialize colors - Color us = color_of_piece_on(from); + Color us = (from != SQ_NONE ? color_of_piece_on(from) : opposite_color(color_of_piece_on(to))); Color them = opposite_color(us); // Initialize pieces @@ -1619,27 +1626,54 @@ int Position::see(Square from, Square to) const { // Find all attackers to the destination square, with the moving piece // removed, but possibly an X-ray attacker added behind it. occ = occupied_squares(); - clear_bit(&occ, from); - attackers = (rook_attacks_bb(to, occ) & rooks_and_queens()) - | (bishop_attacks_bb(to, occ) & bishops_and_queens()) - | (piece_attacks(to) & knights()) - | (piece_attacks(to) & kings()) - | (pawn_attacks(WHITE, to) & pawns(BLACK)) - | (pawn_attacks(BLACK, to) & pawns(WHITE)); - - // If the opponent has no attackers, we are finished + + // Handle enpassant moves + if (ep_square() == to && type_of_piece_on(from) == PAWN) + { + assert(capture == EMPTY); + + Square capQq = (side_to_move() == WHITE)? (to - DELTA_N) : (to - DELTA_S); + capture = piece_on(capQq); + + assert(type_of_piece_on(capQq) == PAWN); + + // Remove the captured pawn + clear_bit(&occ, capQq); + } + + while (true) + { + clear_bit(&occ, from); + attackers = (rook_attacks_bb(to, occ) & rooks_and_queens()) + | (bishop_attacks_bb(to, occ) & bishops_and_queens()) + | (piece_attacks(to) & knights()) + | (piece_attacks(to) & kings()) + | (pawn_attacks(WHITE, to) & pawns(BLACK)) + | (pawn_attacks(BLACK, to) & pawns(WHITE)); + + if (from != SQ_NONE) + break; + + // If we don't have any attacker we are finished + if ((attackers & pieces_of_color(us)) == EmptyBoardBB) + return 0; + + // Locate the least valuable attacker to the destination square + // and use it to initialize from square. + PieceType pt; + for (pt = PAWN; !(attackers & pieces_of_color_and_type(us, pt)); pt++) + assert(pt < KING); + + from = first_1(attackers & pieces_of_color_and_type(us, pt)); + piece = piece_on(from); + } + + // If the opponent has no attackers we are finished if ((attackers & pieces_of_color(them)) == EmptyBoardBB) return seeValues[capture]; attackers &= occ; // Remove the moving piece - // If we don't have any attacker but the moving piece (common case) - // then we loose our piece and gain the opponent attacked one. - // Note that this is not perfect! It does not detect x-rays of - // an our piece behind an opposite one. But is a very rare case. - if ((attackers & pieces_of_color(us)) == EmptyBoardBB) - return seeValues[capture] - seeValues[piece]; - // The destination square is defended, which makes things rather more // difficult to compute. We proceed by building up a "swap list" containing // the material gain or loss at each stop in a sequence of captures to the @@ -1937,8 +1971,7 @@ bool Position::is_mate() { if (is_check()) { - MovePicker mp = MovePicker(*this, false, MOVE_NONE, MOVE_NONE, - MOVE_NONE, MOVE_NONE, Depth(0)); + MovePicker mp = MovePicker(*this, false, MOVE_NONE, EmptySearchStack, Depth(0)); return mp.get_next_move() == MOVE_NONE; } return false;