X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=0d563481c671529dee1474c765172f31fa97a1fc;hp=e7b9bdac3d77620f59b6087e3e58463e448b897b;hb=24dac5ccd309837c6767dcf6b145be385eea2e21;hpb=bffe32f4fe66decd0aa1bd7e39f808c33b3e9410 diff --git a/src/position.cpp b/src/position.cpp index e7b9bdac..0d563481 100644 --- a/src/position.cpp +++ b/src/position.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) 2008-2014 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 @@ -19,15 +20,14 @@ #include #include -#include +#include // For std::memset, std::memcmp #include #include #include "bitcount.h" +#include "misc.h" #include "movegen.h" #include "position.h" -#include "psqtab.h" -#include "rkiss.h" #include "thread.h" #include "tt.h" #include "uci.h" @@ -47,19 +47,18 @@ namespace Zobrist { Key exclusion; } -Key Position::exclusion_key() const { return st->key ^ Zobrist::exclusion;} +Key Position::exclusion_key() const { return st->key ^ Zobrist::exclusion; } namespace { const string PieceToChar(" PNBRQK pnbrqk"); -Score psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB]; // min_attacker() is a helper function used by see() to locate the least // valuable attacker for the side to move, remove the attacker we just found // from the bitboards and scan for new X-ray attacks behind it. -template FORCE_INLINE -PieceType min_attacker(const Bitboard* bb, const Square& to, const Bitboard& stmAttackers, +template +PieceType min_attacker(const Bitboard* bb, Square to, Bitboard stmAttackers, Bitboard& occupied, Bitboard& attackers) { Bitboard b = stmAttackers & bb[Pt]; @@ -78,30 +77,30 @@ PieceType min_attacker(const Bitboard* bb, const Square& to, const Bitboard& stm return (PieceType)Pt; } -template<> FORCE_INLINE -PieceType min_attacker(const Bitboard*, const Square&, const Bitboard&, Bitboard&, Bitboard&) { +template<> +PieceType min_attacker(const Bitboard*, Square, Bitboard, Bitboard&, Bitboard&) { return KING; // No need to update bitboards: it is the last cycle } } // namespace -/// CheckInfo c'tor +/// CheckInfo constructor CheckInfo::CheckInfo(const Position& pos) { Color them = ~pos.side_to_move(); - ksq = pos.king_square(them); + ksq = pos.square(them); pinned = pos.pinned_pieces(pos.side_to_move()); dcCandidates = pos.discovered_check_candidates(); - checkSq[PAWN] = pos.attacks_from(ksq, them); - checkSq[KNIGHT] = pos.attacks_from(ksq); - checkSq[BISHOP] = pos.attacks_from(ksq); - checkSq[ROOK] = pos.attacks_from(ksq); - checkSq[QUEEN] = checkSq[BISHOP] | checkSq[ROOK]; - checkSq[KING] = 0; + checkSquares[PAWN] = pos.attacks_from(ksq, them); + checkSquares[KNIGHT] = pos.attacks_from(ksq); + checkSquares[BISHOP] = pos.attacks_from(ksq); + checkSquares[ROOK] = pos.attacks_from(ksq); + checkSquares[QUEEN] = checkSquares[BISHOP] | checkSquares[ROOK]; + checkSquares[KING] = 0; } @@ -120,70 +119,53 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) { } os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase - << std::setfill('0') << std::setw(16) << pos.st->key << std::dec << "\nCheckers: "; + << std::setfill('0') << std::setw(16) << pos.key() << std::dec << "\nCheckers: "; for (Bitboard b = pos.checkers(); b; ) - os << UCI::format_square(pop_lsb(&b)) << " "; + os << UCI::square(pop_lsb(&b)) << " "; return os; } /// Position::init() initializes at startup the various arrays used to compute -/// hash keys and the piece square tables. The latter is a two-step operation: -/// Firstly, the white halves of the tables are copied from PSQT[] tables. -/// Secondly, the black halves of the tables are initialized by flipping and -/// changing the sign of the white scores. +/// hash keys. void Position::init() { - RKISS rk; + PRNG rng(1070372); for (Color c = WHITE; c <= BLACK; ++c) for (PieceType pt = PAWN; pt <= KING; ++pt) for (Square s = SQ_A1; s <= SQ_H8; ++s) - Zobrist::psq[c][pt][s] = rk.rand(); + Zobrist::psq[c][pt][s] = rng.rand(); for (File f = FILE_A; f <= FILE_H; ++f) - Zobrist::enpassant[f] = rk.rand(); + Zobrist::enpassant[f] = rng.rand(); - for (int cf = NO_CASTLING; cf <= ANY_CASTLING; ++cf) + for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr) { - Bitboard b = cf; + Zobrist::castling[cr] = 0; + Bitboard b = cr; while (b) { Key k = Zobrist::castling[1ULL << pop_lsb(&b)]; - Zobrist::castling[cf] ^= k ? k : rk.rand(); + Zobrist::castling[cr] ^= k ? k : rng.rand(); } } - Zobrist::side = rk.rand(); - Zobrist::exclusion = rk.rand(); - - for (PieceType pt = PAWN; pt <= KING; ++pt) - { - PieceValue[MG][make_piece(BLACK, pt)] = PieceValue[MG][pt]; - PieceValue[EG][make_piece(BLACK, pt)] = PieceValue[EG][pt]; - - Score v = make_score(PieceValue[MG][pt], PieceValue[EG][pt]); - - for (Square s = SQ_A1; s <= SQ_H8; ++s) - { - psq[WHITE][pt][ s] = (v + PSQT[pt][s]); - psq[BLACK][pt][~s] = -(v + PSQT[pt][s]); - } - } + Zobrist::side = rng.rand(); + Zobrist::exclusion = rng.rand(); } -/// Position::operator=() creates a copy of 'pos'. We want the new born Position -/// object to not depend on any external data so we detach state pointer from -/// the source one. +/// Position::operator=() creates a copy of 'pos' but detaching the state pointer +/// from the source to be self-consistent and not depending on any external data. Position& Position::operator=(const Position& pos) { std::memcpy(this, &pos, sizeof(Position)); - startState = *st; + std::memcpy(&startState, st, sizeof(StateInfo)); st = &startState; nodes = 0; @@ -266,7 +248,7 @@ void Position::set(const string& fenStr, bool isChess960, Thread* th) { else if ((idx = PieceToChar.find(token)) != string::npos) { - put_piece(sq, color_of(Piece(idx)), type_of(Piece(idx))); + put_piece(color_of(Piece(idx)), type_of(Piece(idx)), sq); ++sq; } } @@ -285,14 +267,15 @@ void Position::set(const string& fenStr, bool isChess960, Thread* th) { { Square rsq; Color c = islower(token) ? BLACK : WHITE; + Piece rook = make_piece(c, ROOK); token = char(toupper(token)); if (token == 'K') - for (rsq = relative_square(c, SQ_H1); type_of(piece_on(rsq)) != ROOK; --rsq) {} + for (rsq = relative_square(c, SQ_H1); piece_on(rsq) != rook; --rsq) {} else if (token == 'Q') - for (rsq = relative_square(c, SQ_A1); type_of(piece_on(rsq)) != ROOK; ++rsq) {} + for (rsq = relative_square(c, SQ_A1); piece_on(rsq) != rook; ++rsq) {} else if (token >= 'A' && token <= 'H') rsq = make_square(File(token - 'A'), relative_rank(c, RANK_1)); @@ -333,7 +316,7 @@ void Position::set(const string& fenStr, bool isChess960, Thread* th) { void Position::set_castling_right(Color c, Square rfrom) { - Square kfrom = king_square(c); + Square kfrom = square(c); CastlingSide cs = kfrom < rfrom ? KING_SIDE : QUEEN_SIDE; CastlingRight cr = (c | cs); @@ -363,26 +346,26 @@ void Position::set_castling_right(Color c, Square rfrom) { void Position::set_state(StateInfo* si) const { si->key = si->pawnKey = si->materialKey = 0; - si->npMaterial[WHITE] = si->npMaterial[BLACK] = VALUE_ZERO; + si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO; si->psq = SCORE_ZERO; - si->checkersBB = attackers_to(king_square(sideToMove)) & pieces(~sideToMove); + si->checkersBB = attackers_to(square(sideToMove)) & pieces(~sideToMove); for (Bitboard b = pieces(); b; ) { Square s = pop_lsb(&b); Piece pc = piece_on(s); si->key ^= Zobrist::psq[color_of(pc)][type_of(pc)][s]; - si->psq += psq[color_of(pc)][type_of(pc)][s]; + si->psq += PSQT::psq[color_of(pc)][type_of(pc)][s]; } - if (ep_square() != SQ_NONE) - si->key ^= Zobrist::enpassant[file_of(ep_square())]; + if (si->epSquare != SQ_NONE) + si->key ^= Zobrist::enpassant[file_of(si->epSquare)]; if (sideToMove == BLACK) si->key ^= Zobrist::side; - si->key ^= Zobrist::castling[st->castlingRights]; + si->key ^= Zobrist::castling[si->castlingRights]; for (Bitboard b = pieces(PAWN); b; ) { @@ -397,7 +380,7 @@ void Position::set_state(StateInfo* si) const { for (Color c = WHITE; c <= BLACK; ++c) for (PieceType pt = KNIGHT; pt <= QUEEN; ++pt) - si->npMaterial[c] += pieceCount[c][pt] * PieceValue[MG][pt]; + si->nonPawnMaterial[c] += pieceCount[c][pt] * PieceValue[MG][pt]; } @@ -444,7 +427,7 @@ const string Position::fen() const { if (!can_castle(WHITE) && !can_castle(BLACK)) ss << '-'; - ss << (ep_square() == SQ_NONE ? " - " : " " + UCI::format_square(ep_square()) + " ") + ss << (ep_square() == SQ_NONE ? " - " : " " + UCI::square(ep_square()) + " ") << st->rule50 << " " << 1 + (gamePly - (sideToMove == BLACK)) / 2; return ss.str(); @@ -456,7 +439,7 @@ const string Position::fen() const { Phase Position::game_phase() const { - Value npm = st->npMaterial[WHITE] + st->npMaterial[BLACK]; + Value npm = st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK]; npm = std::max(EndgameLimit, std::min(npm, MidgameLimit)); @@ -474,7 +457,7 @@ Phase Position::game_phase() const { Bitboard Position::check_blockers(Color c, Color kingColor) const { Bitboard b, pinners, result = 0; - Square ksq = king_square(kingColor); + Square ksq = square(kingColor); // Pinners are sliders that give check when a pinned piece is removed pinners = ( (pieces( ROOK, QUEEN) & PseudoAttacks[ROOK ][ksq]) @@ -492,16 +475,16 @@ Bitboard Position::check_blockers(Color c, Color kingColor) const { /// Position::attackers_to() computes a bitboard of all pieces which attack a -/// given square. Slider attacks use the occ bitboard to indicate occupancy. +/// given square. Slider attacks use the occupied bitboard to indicate occupancy. -Bitboard Position::attackers_to(Square s, Bitboard occ) const { +Bitboard Position::attackers_to(Square s, Bitboard occupied) const { - return (attacks_from(s, BLACK) & pieces(WHITE, PAWN)) - | (attacks_from(s, WHITE) & pieces(BLACK, PAWN)) - | (attacks_from(s) & pieces(KNIGHT)) - | (attacks_bb(s, occ) & pieces(ROOK, QUEEN)) - | (attacks_bb(s, occ) & pieces(BISHOP, QUEEN)) - | (attacks_from(s) & pieces(KING)); + return (attacks_from(s, BLACK) & pieces(WHITE, PAWN)) + | (attacks_from(s, WHITE) & pieces(BLACK, PAWN)) + | (attacks_from(s) & pieces(KNIGHT)) + | (attacks_bb(s, occupied) & pieces(ROOK, QUEEN)) + | (attacks_bb(s, occupied) & pieces(BISHOP, QUEEN)) + | (attacks_from(s) & pieces(KING)); } @@ -516,25 +499,25 @@ bool Position::legal(Move m, Bitboard pinned) const { Square from = from_sq(m); assert(color_of(moved_piece(m)) == us); - assert(piece_on(king_square(us)) == make_piece(us, KING)); + assert(piece_on(square(us)) == make_piece(us, KING)); // En passant captures are a tricky special case. Because they are rather // uncommon, we do it simply by testing whether the king is attacked after // the move is made. if (type_of(m) == ENPASSANT) { - Square ksq = king_square(us); + Square ksq = square(us); Square to = to_sq(m); Square capsq = to - pawn_push(us); - Bitboard occ = (pieces() ^ from ^ capsq) | to; + Bitboard occupied = (pieces() ^ from ^ capsq) | to; assert(to == ep_square()); assert(moved_piece(m) == make_piece(us, PAWN)); assert(piece_on(capsq) == make_piece(~us, PAWN)); assert(piece_on(to) == NO_PIECE); - return !(attacks_bb< ROOK>(ksq, occ) & pieces(~us, QUEEN, ROOK)) - && !(attacks_bb(ksq, occ) & pieces(~us, QUEEN, BISHOP)); + return !(attacks_bb< ROOK>(ksq, occupied) & pieces(~us, QUEEN, ROOK)) + && !(attacks_bb(ksq, occupied) & pieces(~us, QUEEN, BISHOP)); } // If the moving piece is a king, check whether the destination @@ -547,7 +530,7 @@ bool Position::legal(Move m, Bitboard pinned) const { // is moving along the ray towards or away from the king. return !pinned || !(pinned & from) - || aligned(from, to_sq(m), king_square(us)); + || aligned(from, to_sq(m), square(us)); } @@ -567,7 +550,7 @@ bool Position::pseudo_legal(const Move m) const { return MoveList(*this).contains(m); // Is not a promotion, so promotion piece must be empty - if (promotion_type(m) - 2 != NO_PIECE_TYPE) + if (promotion_type(m) - KNIGHT != NO_PIECE_TYPE) return false; // If the 'from' square is not occupied by a piece belonging to the side to @@ -588,9 +571,7 @@ bool Position::pseudo_legal(const Move m) const { return false; if ( !(attacks_from(from, us) & pieces(~us) & to) // Not a capture - && !((from + pawn_push(us) == to) && empty(to)) // Not a single push - && !( (from + 2 * pawn_push(us) == to) // Not a double push && (rank_of(from) == relative_rank(us, RANK_2)) && empty(to) @@ -612,7 +593,7 @@ bool Position::pseudo_legal(const Move m) const { return false; // Our move must be a blocking evasion or a capture of the checking piece - if (!((between_bb(lsb(checkers()), king_square(us)) | checkers()) & to)) + if (!((between_bb(lsb(checkers()), square(us)) | checkers()) & to)) return false; } // In case of king moves under check we have to remove king so as to catch @@ -635,14 +616,13 @@ bool Position::gives_check(Move m, const CheckInfo& ci) const { Square from = from_sq(m); Square to = to_sq(m); - PieceType pt = type_of(piece_on(from)); // Is there a direct check? - if (ci.checkSq[pt] & to) + if (ci.checkSquares[type_of(piece_on(from))] & to) return true; // Is there a discovered check? - if ( unlikely(ci.dcCandidates) + if ( ci.dcCandidates && (ci.dcCandidates & from) && !aligned(from, to, ci.ksq)) return true; @@ -688,31 +668,21 @@ bool Position::gives_check(Move m, const CheckInfo& ci) const { /// to a StateInfo object. The move is assumed to be legal. Pseudo-legal /// moves should be filtered out before this function is called. -void Position::do_move(Move m, StateInfo& newSt) { - - CheckInfo ci(*this); - do_move(m, newSt, ci, gives_check(m, ci)); -} - -void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) { +void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { assert(is_ok(m)); assert(&newSt != st); ++nodes; - Key k = st->key; + Key k = st->key ^ Zobrist::side; // Copy some fields of the old state to our new StateInfo object except the // ones which are going to be recalculated from scratch anyway and then switch // our state pointer to point to the new (ready to be updated) state. - std::memcpy(&newSt, st, StateCopySize64 * sizeof(uint64_t)); - + std::memcpy(&newSt, st, offsetof(StateInfo, key)); newSt.previous = st; st = &newSt; - // Update side to move - k ^= Zobrist::side; - // Increment ply counters. In particular, rule50 will be reset to zero later on // in case of a capture or a pawn move. ++gamePly; @@ -723,23 +693,22 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI Color them = ~us; Square from = from_sq(m); Square to = to_sq(m); - Piece pc = piece_on(from); - PieceType pt = type_of(pc); + PieceType pt = type_of(piece_on(from)); PieceType captured = type_of(m) == ENPASSANT ? PAWN : type_of(piece_on(to)); - assert(color_of(pc) == us); - assert(piece_on(to) == NO_PIECE || color_of(piece_on(to)) == them || type_of(m) == CASTLING); + assert(color_of(piece_on(from)) == us); + assert(piece_on(to) == NO_PIECE || color_of(piece_on(to)) == (type_of(m) != CASTLING ? them : us)); assert(captured != KING); if (type_of(m) == CASTLING) { - assert(pc == make_piece(us, KING)); + assert(pt == KING); Square rfrom, rto; - do_castling(from, to, rfrom, rto); + do_castling(us, from, to, rfrom, rto); captured = NO_PIECE_TYPE; - st->psq += psq[us][ROOK][rto] - psq[us][ROOK][rfrom]; + st->psq += PSQT::psq[us][ROOK][rto] - PSQT::psq[us][ROOK][rfrom]; k ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto]; } @@ -753,7 +722,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI { if (type_of(m) == ENPASSANT) { - capsq += pawn_push(them); + capsq -= pawn_push(us); assert(pt == PAWN); assert(to == st->epSquare); @@ -761,24 +730,24 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI assert(piece_on(to) == NO_PIECE); assert(piece_on(capsq) == make_piece(them, PAWN)); - board[capsq] = NO_PIECE; + board[capsq] = NO_PIECE; // Not done by remove_piece() } st->pawnKey ^= Zobrist::psq[them][PAWN][capsq]; } else - st->npMaterial[them] -= PieceValue[MG][captured]; + st->nonPawnMaterial[them] -= PieceValue[MG][captured]; // Update board and piece lists - remove_piece(capsq, them, captured); + remove_piece(them, captured, capsq); // Update material hash key and prefetch access to materialTable k ^= Zobrist::psq[them][captured][capsq]; st->materialKey ^= Zobrist::psq[them][captured][pieceCount[them][captured]]; - prefetch((char*)thisThread->materialTable[st->materialKey]); + prefetch(thisThread->materialTable[st->materialKey]); // Update incremental scores - st->psq -= psq[them][captured][capsq]; + st->psq -= PSQT::psq[them][captured][capsq]; // Reset rule 50 counter st->rule50 = 0; @@ -804,16 +773,16 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Move the piece. The tricky Chess960 castling is handled earlier if (type_of(m) != CASTLING) - move_piece(from, to, us, pt); + move_piece(us, pt, from, to); // If the moving piece is a pawn do some special extra work if (pt == PAWN) { // Set en-passant square if the moved pawn can be captured if ( (int(to) ^ int(from)) == 16 - && (attacks_from(from + pawn_push(us), us) & pieces(them, PAWN))) + && (attacks_from(to - pawn_push(us), us) & pieces(them, PAWN))) { - st->epSquare = Square((from + to) / 2); + st->epSquare = (from + to) / 2; k ^= Zobrist::enpassant[file_of(st->epSquare)]; } @@ -824,8 +793,8 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI assert(relative_rank(us, to) == RANK_8); assert(promotion >= KNIGHT && promotion <= QUEEN); - remove_piece(to, us, PAWN); - put_piece(to, us, promotion); + remove_piece(us, PAWN, to); + put_piece(us, promotion, to); // Update hash keys k ^= Zobrist::psq[us][PAWN][to] ^ Zobrist::psq[us][promotion][to]; @@ -834,22 +803,22 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI ^ Zobrist::psq[us][PAWN][pieceCount[us][PAWN]]; // Update incremental score - st->psq += psq[us][promotion][to] - psq[us][PAWN][to]; + st->psq += PSQT::psq[us][promotion][to] - PSQT::psq[us][PAWN][to]; // Update material - st->npMaterial[us] += PieceValue[MG][promotion]; + st->nonPawnMaterial[us] += PieceValue[MG][promotion]; } // Update pawn hash key and prefetch access to pawnsTable st->pawnKey ^= Zobrist::psq[us][PAWN][from] ^ Zobrist::psq[us][PAWN][to]; - prefetch((char*)thisThread->pawnsTable[st->pawnKey]); + prefetch(thisThread->pawnsTable[st->pawnKey]); // Reset rule 50 draw counter st->rule50 = 0; } // Update incremental scores - st->psq += psq[us][pt][to] - psq[us][pt][from]; + st->psq += PSQT::psq[us][pt][to] - PSQT::psq[us][pt][from]; // Set capture piece st->capturedType = captured; @@ -857,30 +826,8 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Update the key with the final value st->key = k; - // Update checkers bitboard: piece must be already moved due to attacks_from() - st->checkersBB = 0; - - if (moveIsCheck) - { - if (type_of(m) != NORMAL) - st->checkersBB = attackers_to(king_square(them)) & pieces(us); - else - { - // Direct checks - if (ci.checkSq[pt] & to) - st->checkersBB |= to; - - // Discovered checks - if (unlikely(ci.dcCandidates) && (ci.dcCandidates & from)) - { - if (pt != ROOK) - st->checkersBB |= attacks_from(king_square(them)) & pieces(us, QUEEN, ROOK); - - if (pt != BISHOP) - st->checkersBB |= attacks_from(king_square(them)) & pieces(us, QUEEN, BISHOP); - } - } - } + // Calculate checkers bitboard (if move gives check) + st->checkersBB = givesCheck ? attackers_to(square(them)) & pieces(us) : 0; sideToMove = ~sideToMove; @@ -907,23 +854,23 @@ void Position::undo_move(Move m) { if (type_of(m) == PROMOTION) { - assert(pt == promotion_type(m)); assert(relative_rank(us, to) == RANK_8); - assert(promotion_type(m) >= KNIGHT && promotion_type(m) <= QUEEN); + assert(pt == promotion_type(m)); + assert(pt >= KNIGHT && pt <= QUEEN); - remove_piece(to, us, promotion_type(m)); - put_piece(to, us, PAWN); + remove_piece(us, pt, to); + put_piece(us, PAWN, to); pt = PAWN; } if (type_of(m) == CASTLING) { Square rfrom, rto; - do_castling(from, to, rfrom, rto); + do_castling(us, from, to, rfrom, rto); } else { - move_piece(to, from, us, pt); // Put the piece back at the source square + move_piece(us, pt, to, from); // Put the piece back at the source square if (st->capturedType) { @@ -937,9 +884,10 @@ void Position::undo_move(Move m) { assert(to == st->previous->epSquare); assert(relative_rank(us, to) == RANK_6); assert(piece_on(capsq) == NO_PIECE); + assert(st->capturedType == PAWN); } - put_piece(capsq, ~us, st->capturedType); // Restore the captured piece + put_piece(~us, st->capturedType, capsq); // Restore the captured piece } } @@ -954,19 +902,19 @@ void Position::undo_move(Move m) { /// Position::do_castling() is a helper used to do/undo a castling move. This /// is a bit tricky, especially in Chess960. template -void Position::do_castling(Square from, Square& to, Square& rfrom, Square& rto) { +void Position::do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto) { bool kingSide = to > from; rfrom = to; // Castling is encoded as "king captures friendly rook" - rto = relative_square(sideToMove, kingSide ? SQ_F1 : SQ_D1); - to = relative_square(sideToMove, kingSide ? SQ_G1 : SQ_C1); + rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1); + to = relative_square(us, kingSide ? SQ_G1 : SQ_C1); // Remove both pieces first since squares could overlap in Chess960 - remove_piece(Do ? from : to, sideToMove, KING); - remove_piece(Do ? rfrom : rto, sideToMove, ROOK); + remove_piece(us, KING, Do ? from : to); + remove_piece(us, ROOK, Do ? rfrom : rto); board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do it for us - put_piece(Do ? to : from, sideToMove, KING); - put_piece(Do ? rto : rfrom, sideToMove, ROOK); + put_piece(us, KING, Do ? to : from); + put_piece(us, ROOK, Do ? rto : rfrom); } @@ -976,9 +924,9 @@ void Position::do_castling(Square from, Square& to, Square& rfrom, Square& rto) void Position::do_null_move(StateInfo& newSt) { assert(!checkers()); + assert(&newSt != st); - std::memcpy(&newSt, st, sizeof(StateInfo)); // Fully copy here - + std::memcpy(&newSt, st, sizeof(StateInfo)); newSt.previous = st; st = &newSt; @@ -989,7 +937,7 @@ void Position::do_null_move(StateInfo& newSt) { } st->key ^= Zobrist::side; - prefetch((char*)TT.first_entry(st->key)); + prefetch(TT.first_entry(st->key)); ++st->rule50; st->pliesFromNull = 0; @@ -1008,7 +956,7 @@ void Position::undo_null_move() { } -/// Position::key_after() computes the new hash key after the given moven. Needed +/// Position::key_after() computes the new hash key after the given move. Needed /// for speculative prefetch. It doesn't recognize special moves like castling, /// en-passant and promotions. @@ -1061,8 +1009,8 @@ Value Position::see(Move m) const { stm = color_of(piece_on(from)); occupied = pieces() ^ from; - // Castling moves are implemented as king capturing the rook so cannot be - // handled correctly. Simply return 0 that is always the correct value + // Castling moves are implemented as king capturing the rook so cannot + // be handled correctly. Simply return VALUE_ZERO that is always correct // unless in the rare case the rook ends up under attack. if (type_of(m) == CASTLING) return VALUE_ZERO; @@ -1099,21 +1047,11 @@ Value Position::see(Move m) const { // Locate and remove the next least valuable attacker captured = min_attacker(byTypeBB, to, stmAttackers, occupied, attackers); - - // Stop before processing a king capture - if (captured == KING) - { - if (stmAttackers == attackers) - ++slIndex; - - break; - } - stm = ~stm; stmAttackers = attackers & pieces(stm); ++slIndex; - } while (stmAttackers); + } while (stmAttackers && (captured != KING || (--slIndex, false))); // Stop before a king capture // Having built the swap list, we negamax through it to find the best // achievable score from the point of view of the side to move. @@ -1124,8 +1062,8 @@ Value Position::see(Move m) const { } -/// Position::is_draw() tests whether the position is drawn by material, 50 moves -/// rule or repetition. It does not detect stalemates. +/// Position::is_draw() tests whether the position is drawn by 50-move rule +/// or by repetition. It does not detect stalemates. bool Position::is_draw() const { @@ -1148,10 +1086,6 @@ bool Position::is_draw() const { /// Position::flip() flips position with the white and black sides reversed. This /// is only useful for debugging e.g. for finding evaluation symmetry bugs. -static char toggle_case(char c) { - return char(islower(c) ? toupper(c) : tolower(c)); -} - void Position::flip() { string f, token; @@ -1169,7 +1103,8 @@ void Position::flip() { ss >> token; // Castling availability f += token + " "; - std::transform(f.begin(), f.end(), f.begin(), toggle_case); + std::transform(f.begin(), f.end(), f.begin(), + [](char c) { return char(islower(c) ? toupper(c) : tolower(c)); }); ss >> token; // En passant square f += (token == "-" ? token : token.replace(1, 1, token[1] == '3' ? "6" : "3")); @@ -1186,96 +1121,77 @@ void Position::flip() { /// Position::pos_is_ok() performs some consistency checks for the position object. /// This is meant to be helpful when debugging. -bool Position::pos_is_ok(int* step) const { - - // Which parts of the position should be verified? - const bool all = false; - - const bool testBitboards = all || false; - const bool testState = all || false; - const bool testKingCount = all || false; - const bool testKingCapture = all || false; - const bool testPieceCounts = all || false; - const bool testPieceList = all || false; - const bool testCastlingSquares = all || false; +bool Position::pos_is_ok(int* failedStep) const { - if (step) - *step = 1; + const bool Fast = true; // Quick (default) or full check? - if ( (sideToMove != WHITE && sideToMove != BLACK) - || piece_on(king_square(WHITE)) != W_KING - || piece_on(king_square(BLACK)) != B_KING - || ( ep_square() != SQ_NONE - && relative_rank(sideToMove, ep_square()) != RANK_6)) - return false; + enum { Default, King, Bitboards, State, Lists, Castling }; - if (step && ++*step, testBitboards) + for (int step = Default; step <= (Fast ? Default : Castling); step++) { - // The intersection of the white and black pieces must be empty - if (pieces(WHITE) & pieces(BLACK)) - return false; - - // The union of the white and black pieces must be equal to all - // occupied squares - if ((pieces(WHITE) | pieces(BLACK)) != pieces()) - return false; + if (failedStep) + *failedStep = step; + + if (step == Default) + if ( (sideToMove != WHITE && sideToMove != BLACK) + || piece_on(square(WHITE)) != W_KING + || piece_on(square(BLACK)) != B_KING + || ( ep_square() != SQ_NONE + && relative_rank(sideToMove, ep_square()) != RANK_6)) + return false; - // Separate piece type bitboards must have empty intersections - for (PieceType p1 = PAWN; p1 <= KING; ++p1) - for (PieceType p2 = PAWN; p2 <= KING; ++p2) - if (p1 != p2 && (pieces(p1) & pieces(p2))) - return false; - } + if (step == King) + if ( std::count(board, board + SQUARE_NB, W_KING) != 1 + || std::count(board, board + SQUARE_NB, B_KING) != 1 + || attackers_to(square(~sideToMove)) & pieces(sideToMove)) + return false; - if (step && ++*step, testState) - { - StateInfo si; - set_state(&si); - if ( st->key != si.key - || st->pawnKey != si.pawnKey - || st->materialKey != si.materialKey - || st->npMaterial[WHITE] != si.npMaterial[WHITE] - || st->npMaterial[BLACK] != si.npMaterial[BLACK] - || st->psq != si.psq - || st->checkersBB != si.checkersBB) - return false; - } + if (step == Bitboards) + { + if ( (pieces(WHITE) & pieces(BLACK)) + ||(pieces(WHITE) | pieces(BLACK)) != pieces()) + return false; - if (step && ++*step, testKingCount) - if ( std::count(board, board + SQUARE_NB, W_KING) != 1 - || std::count(board, board + SQUARE_NB, B_KING) != 1) - return false; + for (PieceType p1 = PAWN; p1 <= KING; ++p1) + for (PieceType p2 = PAWN; p2 <= KING; ++p2) + if (p1 != p2 && (pieces(p1) & pieces(p2))) + return false; + } - if (step && ++*step, testKingCapture) - if (attackers_to(king_square(~sideToMove)) & pieces(sideToMove)) - return false; + if (step == State) + { + StateInfo si = *st; + set_state(&si); + if (std::memcmp(&si, st, sizeof(StateInfo))) + return false; + } - if (step && ++*step, testPieceCounts) - for (Color c = WHITE; c <= BLACK; ++c) - for (PieceType pt = PAWN; pt <= KING; ++pt) - if (pieceCount[c][pt] != popcount(pieces(c, pt))) - return false; - - if (step && ++*step, testPieceList) - for (Color c = WHITE; c <= BLACK; ++c) - for (PieceType pt = PAWN; pt <= KING; ++pt) - for (int i = 0; i < pieceCount[c][pt]; ++i) - if ( board[pieceList[c][pt][i]] != make_piece(c, pt) - || index[pieceList[c][pt][i]] != i) + if (step == Lists) + for (Color c = WHITE; c <= BLACK; ++c) + for (PieceType pt = PAWN; pt <= KING; ++pt) + { + if (pieceCount[c][pt] != popcount(pieces(c, pt))) return false; - if (step && ++*step, testCastlingSquares) - for (Color c = WHITE; c <= BLACK; ++c) - for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1)) - { - if (!can_castle(c | s)) - continue; - - if ( (castlingRightsMask[king_square(c)] & (c | s)) != (c | s) - || piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK) - || castlingRightsMask[castlingRookSquare[c | s]] != (c | s)) - return false; - } + for (int i = 0; i < pieceCount[c][pt]; ++i) + if ( board[pieceList[c][pt][i]] != make_piece(c, pt) + || index[pieceList[c][pt][i]] != i) + return false; + } + + if (step == Castling) + for (Color c = WHITE; c <= BLACK; ++c) + for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1)) + { + if (!can_castle(c | s)) + continue; + + if ( piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK) + || castlingRightsMask[castlingRookSquare[c | s]] != (c | s) + ||(castlingRightsMask[square(c)] & (c | s)) != (c | s)) + return false; + } + } return true; }