X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=922a96fd8bdee8e23c4df7e1382ca486985a961c;hp=cb5370d5b581412af7b800a6ffc891abcca75739;hb=eabba1119f45f2ac8a3a6248bd1c1d9868d7af5c;hpb=fbdabe2975c0e86a04b01c36c9f3eec5494ecf0d diff --git a/src/position.cpp b/src/position.cpp index cb5370d5..922a96fd 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -30,7 +30,6 @@ #include "rkiss.h" #include "thread.h" #include "tt.h" -#include "ucioption.h" using std::string; using std::cout; @@ -78,12 +77,11 @@ namespace { CheckInfo::CheckInfo(const Position& pos) { - Color us = pos.side_to_move(); - Color them = opposite_color(us); + Color them = opposite_color(pos.side_to_move()); Square ksq = pos.king_square(them); - dcCandidates = pos.discovered_check_candidates(us); - pinned = pos.pinned_pieces(us); + pinned = pos.pinned_pieces(); + dcCandidates = pos.discovered_check_candidates(); checkSq[PAWN] = pos.attacks_from(ksq, them); checkSq[KNIGHT] = pos.attacks_from(ksq); @@ -101,9 +99,10 @@ CheckInfo::CheckInfo(const Position& pos) { Position::Position(const Position& pos, int th) { memcpy(this, &pos, sizeof(Position)); - detach(); // Always detach() in copy c'tor to avoid surprises threadID = th; nodes = 0; + + assert(is_ok()); } Position::Position(const string& fen, bool isChess960, int th) { @@ -113,18 +112,6 @@ Position::Position(const string& fen, bool isChess960, int th) { } -/// Position::detach() copies the content of the current state and castling -/// masks inside the position itself. This is needed when the st pointee could -/// become stale, as example because the caller is about to going out of scope. - -void Position::detach() { - - startState = *st; - st = &startState; - st->previous = NULL; // As a safe guard -} - - /// Position::from_fen() initializes the position object with the given FEN /// string. This function is not very robust - make sure that input FENs are /// correct (this is assumed to be the responsibility of the GUI). @@ -203,7 +190,11 @@ void Position::from_fen(const string& fenStr, bool isChess960) { } // 5-6. Halfmove clock and fullmove number - fen >> std::skipws >> st->rule50 >> fullMoves; + fen >> std::skipws >> st->rule50 >> startPosPly; + + // Convert from fullmove starting from 1 to ply starting from 0, + // handle also common incorrect FEN with fullmove = 0. + startPosPly = Max(2 * (startPosPly - 1), 0) + int(sideToMove == BLACK); // Various initialisations chess960 = isChess960; @@ -215,6 +206,8 @@ void Position::from_fen(const string& fenStr, bool isChess960) { st->value = compute_value(); st->npMaterial[WHITE] = compute_non_pawn_material(WHITE); st->npMaterial[BLACK] = compute_non_pawn_material(BLACK); + + assert(is_ok()); } @@ -321,7 +314,7 @@ const string Position::to_fen() const { fen << '-'; fen << (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square())) - << " " << st->rule50 << " " << fullMoves; + << " " << st->rule50 << " " << 1 + (startPosPly - int(sideToMove == BLACK)) / 2; return fen.str(); } @@ -361,36 +354,28 @@ void Position::print(Move move) const { /// Position:hidden_checkers<>() returns a bitboard of all pinned (against the -/// king) pieces for the given color and for the given pinner type. Or, when -/// template parameter FindPinned is false, the pieces of the given color -/// candidate for a discovery check against the enemy king. -/// Bitboard checkersBB must be already updated when looking for pinners. +/// king) pieces for the given color. Or, when template parameter FindPinned is +/// false, the function return the pieces of the given color candidate for a +/// discovery check against the enemy king. template -Bitboard Position::hidden_checkers(Color c) const { - - Bitboard result = EmptyBoardBB; - Bitboard pinners = pieces(FindPinned ? opposite_color(c) : c); - - // Pinned pieces protect our king, dicovery checks attack - // the enemy king. - Square ksq = king_square(FindPinned ? c : opposite_color(c)); +Bitboard Position::hidden_checkers() const { - // Pinners are sliders, not checkers, that give check when candidate pinned is removed - pinners &= (pieces(ROOK, QUEEN) & RookPseudoAttacks[ksq]) | (pieces(BISHOP, QUEEN) & BishopPseudoAttacks[ksq]); + // Pinned pieces protect our king, dicovery checks attack the enemy king + Bitboard b, result = EmptyBoardBB; + Bitboard pinners = pieces(FindPinned ? opposite_color(sideToMove) : sideToMove); + Square ksq = king_square(FindPinned ? sideToMove : opposite_color(sideToMove)); - if (FindPinned && pinners) - pinners &= ~st->checkersBB; + // Pinners are sliders, that give check when candidate pinned is removed + pinners &= (pieces(ROOK, QUEEN) & RookPseudoAttacks[ksq]) + | (pieces(BISHOP, QUEEN) & BishopPseudoAttacks[ksq]); while (pinners) { - Square s = pop_1st_bit(&pinners); - Bitboard b = squares_between(s, ksq) & occupied_squares(); + b = squares_between(ksq, pop_1st_bit(&pinners)) & occupied_squares(); - assert(b); - - if ( !(b & (b - 1)) // Only one bit set? - && (b & pieces(c))) // Is an our piece? + // Only one bit set and is an our piece? + if (b && !(b & (b - 1)) && (b & pieces(sideToMove))) result |= b; } return result; @@ -398,23 +383,21 @@ Bitboard Position::hidden_checkers(Color c) const { /// Position:pinned_pieces() returns a bitboard of all pinned (against the -/// king) pieces for the given color. Note that checkersBB bitboard must -/// be already updated. +/// king) pieces for the side to move. -Bitboard Position::pinned_pieces(Color c) const { +Bitboard Position::pinned_pieces() const { - return hidden_checkers(c); + return hidden_checkers(); } /// Position:discovered_check_candidates() returns a bitboard containing all -/// pieces for the given side which are candidates for giving a discovered -/// check. Contrary to pinned_pieces() here there is no need of checkersBB -/// to be already updated. +/// pieces for the side to move which are candidates for giving a discovered +/// check. -Bitboard Position::discovered_check_candidates(Color c) const { +Bitboard Position::discovered_check_candidates() const { - return hidden_checkers(c); + return hidden_checkers(); } /// Position::attackers_to() computes a bitboard containing all pieces which @@ -503,9 +486,8 @@ bool Position::move_attacks_square(Move m, Square s) const { bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { - assert(is_ok()); assert(move_is_ok(m)); - assert(pinned == pinned_pieces(side_to_move())); + assert(pinned == pinned_pieces()); Color us = side_to_move(); Square from = move_from(m); @@ -520,7 +502,7 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { { Color them = opposite_color(us); Square to = move_to(m); - Square capsq = to + Square(us == WHITE ? -8 : 8); + Square capsq = to + pawn_push(them); Square ksq = king_square(us); Bitboard b = occupied_squares(); @@ -570,8 +552,6 @@ bool Position::move_is_legal(const Move m) const { bool Position::move_is_pl(const Move m) const { - assert(is_ok()); - Color us = sideToMove; Color them = opposite_color(sideToMove); Square from = move_from(m); @@ -694,9 +674,8 @@ bool Position::move_is_pl(const Move m) const { bool Position::move_gives_check(Move m, const CheckInfo& ci) const { - assert(is_ok()); assert(move_is_ok(m)); - assert(ci.dcCandidates == discovered_check_candidates(side_to_move())); + assert(ci.dcCandidates == discovered_check_candidates()); assert(piece_color(piece_on(move_from(m))) == side_to_move()); Square from = move_from(m); @@ -784,30 +763,6 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const { } -/// Position::do_setup_move() makes a permanent move on the board. It should -/// be used when setting up a position on board. You can't undo the move. - -void Position::do_setup_move(Move m) { - - StateInfo newSt; - - // Update the number of full moves after black's move - if (sideToMove == BLACK) - fullMoves++; - - do_move(m, newSt); - - // Reset "game ply" in case we made a non-reversible move. - // "game ply" is used for repetition detection. - if (st->rule50 == 0) - st->gamePly = 0; - - // Our StateInfo newSt is about going out of scope so copy - // its content before it disappears. - detach(); -} - - /// Position::do_move() makes a move, and saves all information necessary /// to a StateInfo object. The move is assumed to be legal. Pseudo-legal /// moves should be filtered out before this function is called. @@ -820,7 +775,6 @@ void Position::do_move(Move m, StateInfo& newSt) { void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) { - assert(is_ok()); assert(move_is_ok(m)); assert(&newSt != st); @@ -832,10 +786,10 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // pointer to point to the new, ready to be updated, state. struct ReducedStateInfo { Key pawnKey, materialKey; - int castleRights, rule50, gamePly, pliesFromNull; - Square epSquare; - Score value; Value npMaterial[2]; + int castleRights, rule50, pliesFromNull; + Score value; + Square epSquare; }; memcpy(&newSt, st, sizeof(ReducedStateInfo)); @@ -843,10 +797,6 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI newSt.previous = st; st = &newSt; - // Save the current key to the history[] array, in order to be able to - // detect repetition draws. - history[st->gamePly++] = key; - // Update side to move key ^= zobSideToMove; @@ -930,7 +880,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Set en passant square, only if moved pawn can be captured if ((to ^ from) == 16) { - if (attacks_from(from + (us == WHITE ? DELTA_N : DELTA_S), us) & pieces(PAWN, them)) + if (attacks_from(from + pawn_push(us), us) & pieces(PAWN, them)) { st->epSquare = Square((int(from) + int(to)) / 2); key ^= zobEp[st->epSquare]; @@ -1039,7 +989,7 @@ void Position::do_capture_move(Key& key, PieceType capture, Color them, Square t { if (ep) // en passant ? { - capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S); + capsq = to + pawn_push(them); assert(to == st->epSquare); assert(relative_rank(opposite_color(them), to) == RANK_6); @@ -1192,7 +1142,6 @@ void Position::do_castle_move(Move m) { void Position::undo_move(Move m) { - assert(is_ok()); assert(move_is_ok(m)); sideToMove = opposite_color(sideToMove); @@ -1262,7 +1211,7 @@ void Position::undo_move(Move m) { Square capsq = to; if (ep) - capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); + capsq = to - pawn_push(us); assert(st->capturedType != KING); assert(!ep || square_is_empty(capsq)); @@ -1366,7 +1315,6 @@ void Position::undo_castle_move(Move m) { void Position::do_null_move(StateInfo& backupSt) { - assert(is_ok()); assert(!in_check()); // Back up the information necessary to undo the null move to the supplied @@ -1380,10 +1328,6 @@ void Position::do_null_move(StateInfo& backupSt) { backupSt.pliesFromNull = st->pliesFromNull; st->previous = &backupSt; - // Save the current key to the history[] array, in order to be able to - // detect repetition draws. - history[st->gamePly++] = st->key; - // Update the necessary information if (st->epSquare != SQ_NONE) st->key ^= zobEp[st->epSquare]; @@ -1396,6 +1340,8 @@ void Position::do_null_move(StateInfo& backupSt) { st->rule50++; st->pliesFromNull = 0; st->value += (sideToMove == WHITE) ? TempoValue : -TempoValue; + + assert(is_ok()); } @@ -1403,7 +1349,6 @@ void Position::do_null_move(StateInfo& backupSt) { void Position::undo_null_move() { - assert(is_ok()); assert(!in_check()); // Restore information from the our backup StateInfo object @@ -1417,7 +1362,8 @@ void Position::undo_null_move() { // Update the necessary information sideToMove = opposite_color(sideToMove); st->rule50--; - st->gamePly--; + + assert(is_ok()); } @@ -1467,7 +1413,7 @@ int Position::see(Move m) const { // Handle en passant moves if (st->epSquare == to && piece_type(piece_on(from)) == PAWN) { - Square capQq = (side_to_move() == WHITE ? to - DELTA_N : to - DELTA_S); + Square capQq = to - pawn_push(side_to_move()); assert(capturedType == PIECE_TYPE_NONE); assert(piece_type(piece_on(capQq)) == PAWN); @@ -1566,7 +1512,6 @@ void Position::clear() { castleRightsMask[sq] = ALL_CASTLES; } sideToMove = WHITE; - fullMoves = 1; nodes = 0; } @@ -1707,9 +1652,24 @@ bool Position::is_draw() const { // Draw by repetition? if (!SkipRepetition) - for (int i = 4, e = Min(Min(st->gamePly, st->rule50), st->pliesFromNull); i <= e; i += 2) - if (history[st->gamePly - i] == st->key) - return true; + { + int i = 4, e = Min(st->rule50, st->pliesFromNull); + + if (i <= e) + { + StateInfo* stp = st->previous->previous; + + do { + stp = stp->previous->previous; + + if (stp->key == st->key) + return true; + + i +=2; + + } while (i <= e); + } + } return false; } @@ -1768,8 +1728,6 @@ void Position::init() { void Position::flip() { - assert(is_ok()); - // Make a copy of current position before to start changing const Position pos(*this, threadID);