/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
using std::string;
+namespace Stockfish {
+
namespace Zobrist {
Key psq[PIECE_NB][SQUARE_NB];
<< std::setfill(' ') << std::dec << "\nCheckers: ";
for (Bitboard b = pos.checkers(); b; )
- os << UCI::square(pop_lsb(&b)) << " ";
+ os << UCI::square(pop_lsb(b)) << " ";
if ( int(Tablebases::MaxCardinality) >= popcount(pos.pieces())
&& !pos.can_castle(ANY_CASTLING))
{
StateInfo st;
+ ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize);
+
Position p;
p.set(pos.fen(), pos.is_chess960(), &st, pos.this_thread());
Tablebases::ProbeState s1, s2;
std::memset(this, 0, sizeof(Position));
std::memset(si, 0, sizeof(StateInfo));
- std::fill_n(&pieceList[0][0], sizeof(pieceList) / sizeof(Square), SQ_NONE);
st = si;
ss >> std::noskipws;
else if (token == '/')
sq += 2 * SOUTH;
- else if ((idx = PieceToChar.find(token)) != string::npos)
- {
+ else if ((idx = PieceToChar.find(token)) != string::npos) {
put_piece(Piece(idx), sq);
++sq;
}
Square kto = relative_square(c, cr & KING_SIDE ? SQ_G1 : SQ_C1);
Square rto = relative_square(c, cr & KING_SIDE ? SQ_F1 : SQ_D1);
- castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto)
+ castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto))
& ~(kfrom | rfrom);
}
for (Bitboard b = pieces(); b; )
{
- Square s = pop_lsb(&b);
+ Square s = pop_lsb(b);
Piece pc = piece_on(s);
si->key ^= Zobrist::psq[pc][s];
/// Position::fen() returns a FEN representation of the position. In case of
/// Chess960 the Shredder-FEN notation is used. This is mainly a debugging function.
-const string Position::fen() const {
+string Position::fen() const {
int emptyCnt;
std::ostringstream ss;
while (snipers)
{
- Square sniperSq = pop_lsb(&snipers);
+ Square sniperSq = pop_lsb(snipers);
Bitboard b = between_bb(s, sniperSq) & occupancy;
if (b && !more_than_one(b))
// 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)
+ if (type_of(m) == EN_PASSANT)
{
Square ksq = square<KING>(us);
Square capsq = to - pawn_push(us);
if (attackers_to(s) & pieces(~us))
return false;
- // In case of Chess960, verify that when moving the castling rook we do
- // not discover some hidden checker.
+ // In case of Chess960, verify if the Rook blocks some checks
// For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
- return !chess960
- || !(attacks_bb<ROOK>(to, pieces() ^ to_sq(m)) & pieces(~us, ROOK, QUEEN));
+ return !chess960 || !(blockers_for_king(us) & to_sq(m));
}
// If the moving piece is a king, check whether the destination square is
// attacked by the opponent.
if (type_of(piece_on(from)) == KING)
- return !(attackers_to(to) & pieces(~us));
+ return !(attackers_to(to, pieces() ^ from) & pieces(~us));
// 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.
- return !(blockers_for_king(us) & from)
- || aligned(from, to, square<KING>(us));
+ return !(blockers_for_king(us) & from)
+ || aligned(from, to, square<KING>(us));
}
Piece pc = moved_piece(m);
// Use a slower but simpler function for uncommon cases
+ // yet we skip the legality check of MoveList<LEGAL>().
if (type_of(m) != NORMAL)
- return MoveList<LEGAL>(*this).contains(m);
+ return checkers() ? MoveList< EVASIONS>(*this).contains(m)
+ : MoveList<NON_EVASIONS>(*this).contains(m);
// Is not a promotion, so promotion piece must be empty
if (promotion_type(m) - KNIGHT != NO_PIECE_TYPE)
if (more_than_one(checkers()))
return false;
- // Our move must be a blocking evasion or a capture of the checking piece
- if (!((between_bb(lsb(checkers()), square<KING>(us)) | checkers()) & to))
+ // Our move must be a blocking interposition or a capture of the checking piece
+ if (!(between_bb(square<KING>(us), lsb(checkers())) & to))
return false;
}
// In case of king moves under check we have to remove king so as to catch
// of direct checks and ordinary discovered check, so the only case we
// need to handle is the unusual case of a discovered check through
// the captured pawn.
- case ENPASSANT:
+ case EN_PASSANT:
{
Square capsq = make_square(file_of(to), rank_of(from));
Bitboard b = (pieces() ^ from ^ capsq) | to;
return (attacks_bb< ROOK>(square<KING>(~sideToMove), b) & pieces(sideToMove, QUEEN, ROOK))
| (attacks_bb<BISHOP>(square<KING>(~sideToMove), b) & pieces(sideToMove, QUEEN, BISHOP));
}
- case CASTLING:
+ default: //CASTLING
{
- Square kfrom = from;
- Square rfrom = to; // Castling is encoded as 'king captures the rook'
- Square kto = relative_square(sideToMove, rfrom > kfrom ? SQ_G1 : SQ_C1);
- Square rto = relative_square(sideToMove, rfrom > kfrom ? SQ_F1 : SQ_D1);
+ // Castling is encoded as 'king captures the rook'
+ Square ksq = square<KING>(~sideToMove);
+ Square rto = relative_square(sideToMove, to > from ? SQ_F1 : SQ_D1);
- return (attacks_bb<ROOK>(rto) & square<KING>(~sideToMove))
- && (attacks_bb<ROOK>(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & square<KING>(~sideToMove));
+ return (attacks_bb<ROOK>(rto) & ksq)
+ && (attacks_bb<ROOK>(rto, pieces() ^ from ^ to) & ksq);
}
- default:
- assert(false);
- return false;
}
}
++st->rule50;
++st->pliesFromNull;
+ // Used by NNUE
+ st->accumulator.computed[WHITE] = false;
+ st->accumulator.computed[BLACK] = false;
+ auto& dp = st->dirtyPiece;
+ dp.dirty_num = 1;
+
Color us = sideToMove;
Color them = ~us;
Square from = from_sq(m);
Square to = to_sq(m);
Piece pc = piece_on(from);
- Piece captured = type_of(m) == ENPASSANT ? make_piece(them, PAWN) : piece_on(to);
+ Piece captured = type_of(m) == EN_PASSANT ? make_piece(them, PAWN) : piece_on(to);
assert(color_of(pc) == us);
assert(captured == NO_PIECE || color_of(captured) == (type_of(m) != CASTLING ? them : us));
// update non-pawn material.
if (type_of(captured) == PAWN)
{
- if (type_of(m) == ENPASSANT)
+ if (type_of(m) == EN_PASSANT)
{
capsq -= pawn_push(us);
else
st->nonPawnMaterial[them] -= PieceValue[MG][captured];
+ if (Eval::useNNUE)
+ {
+ dp.dirty_num = 2; // 1 piece moved, 1 piece captured
+ dp.piece[1] = captured;
+ dp.from[1] = capsq;
+ dp.to[1] = SQ_NONE;
+ }
+
// Update board and piece lists
remove_piece(capsq);
- if (type_of(m) == ENPASSANT)
+ if (type_of(m) == EN_PASSANT)
board[capsq] = NO_PIECE;
// Update material hash key and prefetch access to materialTable
// Move the piece. The tricky Chess960 castling is handled earlier
if (type_of(m) != CASTLING)
+ {
+ if (Eval::useNNUE)
+ {
+ dp.piece[0] = pc;
+ dp.from[0] = from;
+ dp.to[0] = to;
+ }
+
move_piece(from, to);
+ }
// If the moving piece is a pawn do some special extra work
if (type_of(pc) == PAWN)
{
- // Set en-passant square if the moved pawn can be captured
+ // Set en passant square if the moved pawn can be captured
if ( (int(to) ^ int(from)) == 16
&& (pawn_attacks_bb(us, to - pawn_push(us)) & pieces(them, PAWN)))
{
remove_piece(to);
put_piece(promotion, to);
+ if (Eval::useNNUE)
+ {
+ // Promoting pawn to SQ_NONE, promoted piece from SQ_NONE
+ dp.to[0] = SQ_NONE;
+ dp.piece[dp.dirty_num] = promotion;
+ dp.from[dp.dirty_num] = SQ_NONE;
+ dp.to[dp.dirty_num] = to;
+ dp.dirty_num++;
+ }
+
// Update hash keys
k ^= Zobrist::psq[pc][to] ^ Zobrist::psq[promotion][to];
st->pawnKey ^= Zobrist::psq[pc][to];
{
Square capsq = to;
- if (type_of(m) == ENPASSANT)
+ if (type_of(m) == EN_PASSANT)
{
capsq -= pawn_push(us);
rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1);
to = relative_square(us, kingSide ? SQ_G1 : SQ_C1);
+ if (Do && Eval::useNNUE)
+ {
+ auto& dp = st->dirtyPiece;
+ dp.piece[0] = make_piece(us, KING);
+ dp.from[0] = from;
+ dp.to[0] = to;
+ dp.piece[1] = make_piece(us, ROOK);
+ dp.from[1] = rfrom;
+ dp.to[1] = rto;
+ dp.dirty_num = 2;
+ }
+
// Remove both pieces first since squares could overlap in Chess960
remove_piece(Do ? from : to);
remove_piece(Do ? rfrom : rto);
}
-/// Position::do(undo)_null_move() is used to do(undo) a "null move": it flips
+/// Position::do_null_move() is used to do a "null move": it flips
/// the side to move without executing any move on the board.
void Position::do_null_move(StateInfo& newSt) {
assert(!checkers());
assert(&newSt != st);
- std::memcpy(&newSt, st, sizeof(StateInfo));
+ std::memcpy(&newSt, st, offsetof(StateInfo, accumulator));
+
newSt.previous = st;
st = &newSt;
+ st->dirtyPiece.dirty_num = 0;
+ st->dirtyPiece.piece[0] = NO_PIECE; // Avoid checks in UpdateAccumulator()
+ st->accumulator.computed[WHITE] = false;
+ st->accumulator.computed[BLACK] = false;
+
if (st->epSquare != SQ_NONE)
{
st->key ^= Zobrist::enpassant[file_of(st->epSquare)];
}
st->key ^= Zobrist::side;
- prefetch(TT.first_entry(st->key));
+ prefetch(TT.first_entry(key()));
++st->rule50;
st->pliesFromNull = 0;
assert(pos_is_ok());
}
+
+/// Position::undo_null_move() must be used to undo a "null move"
+
void Position::undo_null_move() {
assert(!checkers());
/// 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.
+/// en passant and promotions.
Key Position::key_after(Move m) const {
assert(is_ok(m));
- // Only deal with normal moves, assume others pass a simple see
+ // Only deal with normal moves, assume others pass a simple SEE
if (type_of(m) != NORMAL)
return VALUE_ZERO >= threshold;
if (swap <= 0)
return true;
+ assert(color_of(piece_on(from)) == sideToMove);
Bitboard occupied = pieces() ^ from ^ to;
- Color stm = color_of(piece_on(from));
+ Color stm = sideToMove;
Bitboard attackers = attackers_to(to, occupied);
Bitboard stmAttackers, bb;
int res = 1;
if (!(stmAttackers = attackers & pieces(stm)))
break;
- // Don't allow pinned pieces to attack (except the king) as long as
- // there are pinners on their original square.
- if (st->pinners[~stm] & occupied)
- stmAttackers &= ~st->blockersForKing[stm];
+ // Don't allow pinned pieces to attack as long as there are
+ // pinners on their original square.
+ if (pinners(~stm) & occupied)
+ stmAttackers &= ~blockers_for_king(stm);
if (!stmAttackers)
break;
if ((swap = PawnValueMg - swap) < res)
break;
- occupied ^= lsb(bb);
+ occupied ^= least_significant_square_bb(bb);
attackers |= attacks_bb<BISHOP>(to, occupied) & pieces(BISHOP, QUEEN);
}
if ((swap = KnightValueMg - swap) < res)
break;
- occupied ^= lsb(bb);
+ occupied ^= least_significant_square_bb(bb);
}
else if ((bb = stmAttackers & pieces(BISHOP)))
if ((swap = BishopValueMg - swap) < res)
break;
- occupied ^= lsb(bb);
+ occupied ^= least_significant_square_bb(bb);
attackers |= attacks_bb<BISHOP>(to, occupied) & pieces(BISHOP, QUEEN);
}
if ((swap = RookValueMg - swap) < res)
break;
- occupied ^= lsb(bb);
+ occupied ^= least_significant_square_bb(bb);
attackers |= attacks_bb<ROOK>(to, occupied) & pieces(ROOK, QUEEN);
}
if ((swap = QueenValueMg - swap) < res)
break;
- occupied ^= lsb(bb);
+ occupied ^= least_significant_square_bb(bb);
attackers |= (attacks_bb<BISHOP>(to, occupied) & pieces(BISHOP, QUEEN))
| (attacks_bb<ROOK >(to, occupied) & pieces(ROOK , QUEEN));
}
Square s1 = from_sq(move);
Square s2 = to_sq(move);
- if (!(between_bb(s1, s2) & pieces()))
+ if (!((between_bb(s1, s2) ^ s2) & pieces()))
{
if (ply > i)
return true;
assert(0 && "pos_is_ok: Bitboards");
StateInfo si = *st;
+ ASSERT_ALIGNED(&si, Eval::NNUE::CacheLineSize);
+
set_state(&si);
if (std::memcmp(&si, st, sizeof(StateInfo)))
assert(0 && "pos_is_ok: State");
for (Piece pc : Pieces)
- {
if ( pieceCount[pc] != popcount(pieces(color_of(pc), type_of(pc)))
|| pieceCount[pc] != std::count(board, board + SQUARE_NB, pc))
assert(0 && "pos_is_ok: Pieces");
- for (int i = 0; i < pieceCount[pc]; ++i)
- if (board[pieceList[pc][i]] != pc || index[pieceList[pc][i]] != i)
- assert(0 && "pos_is_ok: Index");
- }
-
for (Color c : { WHITE, BLACK })
for (CastlingRights cr : {c & KING_SIDE, c & QUEEN_SIDE})
{
return true;
}
+
+} // namespace Stockfish