#include "rkiss.h"
#include "thread.h"
#include "tt.h"
-#include "ucioption.h"
using std::string;
using std::cout;
Key Position::zobSideToMove;
Key Position::zobExclusion;
-Score Position::PieceSquareTable[16][64];
+Score Position::pieceSquareTable[16][64];
// Material values arrays, indexed by Piece
const Value PieceValueMidgame[17] = {
CheckInfo::CheckInfo(const Position& pos) {
- Color us = pos.side_to_move();
- Color them = opposite_color(us);
+ Color them = flip(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<PAWN>(ksq, them);
checkSq[KNIGHT] = pos.attacks_from<KNIGHT>(ksq);
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) {
}
-/// 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).
-void Position::from_fen(const string& fen, bool isChess960) {
+void Position::from_fen(const string& fenStr, bool isChess960) {
/*
A FEN string defines a particular position using only the ASCII character set.
char col, row, token;
size_t p;
Square sq = SQ_A8;
- std::istringstream ss(fen);
+ std::istringstream fen(fenStr);
clear();
- ss >> std::noskipws;
+ fen >> std::noskipws;
// 1. Piece placement
- while ((ss >> token) && !isspace(token))
+ while ((fen >> token) && !isspace(token))
{
if (token == '/')
sq -= Square(16); // Jump back of 2 rows
}
// 2. Active color
- ss >> token;
+ fen >> token;
sideToMove = (token == 'w' ? WHITE : BLACK);
- ss >> token;
+ fen >> token;
// 3. Castling availability
- while ((ss >> token) && !isspace(token))
+ while ((fen >> token) && !isspace(token))
set_castling_rights(token);
// 4. En passant square. Ignore if no pawn capture is possible
- if ( ((ss >> col) && (col >= 'a' && col <= 'h'))
- && ((ss >> row) && (row == '3' || row == '6')))
+ if ( ((fen >> col) && (col >= 'a' && col <= 'h'))
+ && ((fen >> row) && (row == '3' || row == '6')))
{
st->epSquare = make_square(File(col - 'a'), Rank(row - '1'));
- Color them = opposite_color(sideToMove);
+ Color them = flip(sideToMove);
if (!(attacks_from<PAWN>(st->epSquare, them) & pieces(PAWN, sideToMove)))
st->epSquare = SQ_NONE;
}
// 5-6. Halfmove clock and fullmove number
- ss >> 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;
- find_checkers();
+ st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(flip(sideToMove));
st->key = compute_key();
st->pawnKey = compute_pawn_key();
st->value = compute_value();
st->npMaterial[WHITE] = compute_non_pawn_material(WHITE);
st->npMaterial[BLACK] = compute_non_pawn_material(BLACK);
+
+ assert(is_ok());
}
else return;
- if (square_file(rsq) < square_file(ksq))
+ if (file_of(rsq) < file_of(ksq))
set_castle(WHITE_OOO << c, ksq, rsq);
else
set_castle(WHITE_OO << c, ksq, rsq);
const string Position::to_fen() const {
- string fen;
+ std::ostringstream fen;
Square sq;
- char emptyCnt;
+ int emptyCnt;
- for (Rank rank = RANK_8; rank >= RANK_1; rank--, fen += '/')
+ for (Rank rank = RANK_8; rank >= RANK_1; rank--)
{
- emptyCnt = '0';
+ emptyCnt = 0;
for (File file = FILE_A; file <= FILE_H; file++)
{
if (!square_is_empty(sq))
{
- if (emptyCnt != '0')
+ if (emptyCnt)
{
- fen += emptyCnt;
- emptyCnt = '0';
+ fen << emptyCnt;
+ emptyCnt = 0;
}
- fen += PieceToChar[piece_on(sq)];
- } else
+ fen << PieceToChar[piece_on(sq)];
+ }
+ else
emptyCnt++;
}
- if (emptyCnt != '0')
- fen += emptyCnt;
+ if (emptyCnt)
+ fen << emptyCnt;
+
+ if (rank > RANK_1)
+ fen << '/';
}
- fen += (sideToMove == WHITE ? " w " : " b ");
+ fen << (sideToMove == WHITE ? " w " : " b ");
if (st->castleRights != CASTLES_NONE)
{
if (can_castle(WHITE_OO))
- fen += chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OO))))) : 'K';
+ fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE_OO))))) : 'K');
if (can_castle(WHITE_OOO))
- fen += chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OOO))))) : 'Q';
+ fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE_OOO))))) : 'Q');
if (can_castle(BLACK_OO))
- fen += chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OO))) : 'k';
+ fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK_OO))) : 'k');
if (can_castle(BLACK_OOO))
- fen += chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OOO))) : 'q';
+ fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK_OOO))) : 'q');
} else
- fen += '-';
+ fen << '-';
- fen += (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square()));
- return fen;
+ fen << (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square()))
+ << " " << st->rule50 << " " << 1 + (startPosPly - int(sideToMove == BLACK)) / 2;
+
+ return fen.str();
}
if (move)
{
Position p(*this, thread());
- string dd = (piece_color(piece_on(move_from(move))) == BLACK ? ".." : "");
+ string dd = (sideToMove == BLACK ? ".." : "");
cout << "\nMove is: " << dd << move_to_san(p, move);
}
Square sq = make_square(file, rank);
Piece piece = piece_on(sq);
- if (piece == PIECE_NONE && square_color(sq) == DARK)
+ if (piece == PIECE_NONE && color_of(sq) == DARK)
piece = PIECE_NONE_DARK_SQ;
- char c = (piece_color(piece_on(sq)) == BLACK ? '=' : ' ');
+ char c = (color_of(piece_on(sq)) == BLACK ? '=' : ' ');
cout << c << PieceToChar[piece] << c << '|';
}
}
/// 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<bool FindPinned>
-Bitboard Position::hidden_checkers(Color c) const {
-
- Bitboard result = EmptyBoardBB;
- Bitboard pinners = pieces(FindPinned ? opposite_color(c) : c);
+Bitboard Position::hidden_checkers() const {
- // Pinned pieces protect our king, dicovery checks attack
- // the enemy king.
- Square ksq = king_square(FindPinned ? c : opposite_color(c));
+ // Pinned pieces protect our king, dicovery checks attack the enemy king
+ Bitboard b, result = EmptyBoardBB;
+ Bitboard pinners = pieces(FindPinned ? flip(sideToMove) : sideToMove);
+ Square ksq = king_square(FindPinned ? sideToMove : flip(sideToMove));
- // Pinners are sliders, not checkers, that give check when candidate pinned is removed
- pinners &= (pieces(ROOK, QUEEN) & RookPseudoAttacks[ksq]) | (pieces(BISHOP, QUEEN) & BishopPseudoAttacks[ksq]);
-
- 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();
-
- assert(b);
+ b = squares_between(ksq, pop_1st_bit(&pinners)) & occupied_squares();
- 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;
/// 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<true>(c);
+ return hidden_checkers<true>();
}
/// 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<false>(c);
+ return hidden_checkers<false>();
}
/// Position::attackers_to() computes a bitboard containing all pieces which
bool Position::move_attacks_square(Move m, Square s) const {
- assert(move_is_ok(m));
+ assert(is_ok(m));
assert(square_is_ok(s));
Bitboard occ, xray;
do_move_bb(&occ, make_move_bb(f, t));
xray = ( (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN))
|(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN)))
- & pieces(piece_color(piece_on(f)));
+ & pieces(color_of(piece_on(f)));
// If we have attacks we need to verify that are caused by our move
// and are not already existent ones.
}
-/// 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::attackers_to, which is probably
-/// inefficient. Consider rewriting this function to use the last move
-/// played, like in non-bitboard versions of Glaurung.
-
-void Position::find_checkers() {
-
- Color us = side_to_move();
- st->checkersBB = attackers_to(king_square(us)) & pieces(opposite_color(us));
-}
-
-
/// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
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(is_ok(m));
+ assert(pinned == pinned_pieces());
Color us = side_to_move();
Square from = move_from(m);
- assert(piece_color(piece_on(from)) == us);
+ assert(color_of(piece_on(from)) == us);
assert(piece_on(king_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 (move_is_ep(m))
+ // 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 (is_enpassant(m))
{
- Color them = opposite_color(us);
+ Color them = flip(us);
Square to = move_to(m);
- Square capsq = make_square(square_file(to), square_rank(from));
+ Square capsq = to + pawn_push(them);
Square ksq = king_square(us);
Bitboard b = occupied_squares();
// If the moving piece is a king, check whether the destination
// square is attacked by the opponent. Castling moves are checked
// for legality during move generation.
- if (piece_type(piece_on(from)) == KING)
- return move_is_castle(m) || !(attackers_to(move_to(m)) & pieces(opposite_color(us)));
+ if (type_of(piece_on(from)) == KING)
+ return is_castle(m) || !(attackers_to(move_to(m)) & pieces(flip(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.
}
-/// Position::move_is_pl_slow() takes a move and tests whether the move
-/// is pseudo legal. This version is not very fast and should be used
-/// only in non time-critical paths.
-
-bool Position::move_is_pl_slow(const Move m) const {
-
- MoveStack mlist[MAX_MOVES];
- MoveStack *cur, *last;
+/// Position::move_is_legal() takes a random move and tests whether the move
+/// is legal. This version is not very fast and should be used only
+/// in non time-critical paths.
- last = in_check() ? generate<MV_EVASION>(*this, mlist)
- : generate<MV_NON_EVASION>(*this, mlist);
+bool Position::move_is_legal(const Move m) const {
- for (cur = mlist; cur != last; cur++)
- if (cur->move == m)
+ for (MoveList<MV_LEGAL> ml(*this); !ml.end(); ++ml)
+ if (ml.move() == m)
return true;
return false;
}
-/// Fast version of Position::move_is_pl() that takes a move and a bitboard
-/// of pinned pieces as input, and tests whether the move is pseudo legal.
+/// Position::is_pseudo_legal() takes a random move and tests whether the move
+/// is pseudo legal. It is used to validate moves from TT that can be corrupted
+/// due to SMP concurrent access or hash position key aliasing.
-bool Position::move_is_pl(const Move m) const {
-
- assert(is_ok());
+bool Position::is_pseudo_legal(const Move m) const {
Color us = sideToMove;
- Color them = opposite_color(sideToMove);
+ Color them = flip(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_pl_slow(m);
+ if (is_special(m))
+ return move_is_legal(m);
// Is not a promotion, so promotion piece must be empty
if (promotion_piece_type(m) - 2 != PIECE_TYPE_NONE)
// If the from square is not occupied by a piece belonging to the side to
// move, the move is obviously not legal.
- if (pc == PIECE_NONE || piece_color(pc) != us)
+ if (pc == PIECE_NONE || color_of(pc) != us)
return false;
// The destination square cannot be occupied by a friendly piece
- if (piece_color(piece_on(to)) == us)
+ if (color_of(piece_on(to)) == us)
return false;
// Handle the special case of a pawn move
- if (piece_type(pc) == PAWN)
+ if (type_of(pc) == PAWN)
{
// Move direction must be compatible with pawn color
int direction = to - from;
// 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)
+ if (rank_of(to) == RANK_8 || rank_of(to) == RANK_1)
return false;
// Proceed according to the square delta between the origin and
case DELTA_SE:
// Capture. The destination square must be occupied by an enemy
// piece (en passant captures was handled earlier).
- if (piece_color(piece_on(to)) != them)
+ if (color_of(piece_on(to)) != them)
return false;
// From and to files must be one file apart, avoids a7h5
- if (abs(square_file(from) - square_file(to)) != 1)
+ if (abs(file_of(from) - file_of(to)) != 1)
return false;
break;
// 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
+ if ( rank_of(to) != RANK_4
|| !square_is_empty(to)
|| !square_is_empty(from + DELTA_N))
return false;
// 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
+ if ( rank_of(to) != RANK_5
|| !square_is_empty(to)
|| !square_is_empty(from + DELTA_S))
return false;
{
// In case of king moves under check we have to remove king so to catch
// as invalid moves like b1a1 when opposite queen is on c1.
- if (piece_type(piece_on(from)) == KING)
+ if (type_of(piece_on(from)) == KING)
{
Bitboard b = occupied_squares();
clear_bit(&b, from);
- if (attackers_to(move_to(m), b) & pieces(opposite_color(us)))
+ if (attackers_to(move_to(m), b) & pieces(flip(us)))
return false;
}
else
}
-/// Position::move_gives_check() tests whether a pseudo-legal move is a check
+/// Position::move_gives_check() tests whether a pseudo-legal move gives a check
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(piece_color(piece_on(move_from(m))) == side_to_move());
+ assert(is_ok(m));
+ assert(ci.dcCandidates == discovered_check_candidates());
+ assert(color_of(piece_on(move_from(m))) == side_to_move());
Square from = move_from(m);
Square to = move_to(m);
- PieceType pt = piece_type(piece_on(from));
+ PieceType pt = type_of(piece_on(from));
// Direct check ?
if (bit_is_set(ci.checkSq[pt], to))
{
// For pawn and king moves we need to verify also direction
if ( (pt != PAWN && pt != KING)
- || !squares_aligned(from, to, king_square(opposite_color(side_to_move()))))
+ || !squares_aligned(from, to, king_square(flip(side_to_move()))))
return true;
}
// Can we skip the ugly special cases ?
- if (!move_is_special(m))
+ if (!is_special(m))
return false;
Color us = side_to_move();
Bitboard b = occupied_squares();
- Square ksq = king_square(opposite_color(us));
+ Square ksq = king_square(flip(us));
// Promotion with check ?
- if (move_is_promotion(m))
+ if (is_promotion(m))
{
clear_bit(&b, from);
// of direct checks and ordinary discovered check, the only case we
// need to handle is the unusual case of a discovered check through
// the captured pawn.
- if (move_is_ep(m))
+ if (is_enpassant(m))
{
- Square capsq = make_square(square_file(to), square_rank(from));
+ Square capsq = make_square(file_of(to), rank_of(from));
clear_bit(&b, from);
clear_bit(&b, capsq);
set_bit(&b, to);
}
// Castling with check ?
- if (move_is_castle(m))
+ if (is_castle(m))
{
Square kfrom, kto, rfrom, rto;
kfrom = from;
}
-/// 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.
void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) {
- assert(is_ok());
- assert(move_is_ok(m));
+ assert(is_ok(m));
assert(&newSt != st);
nodes++;
// 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));
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;
st->rule50++;
st->pliesFromNull++;
- if (move_is_castle(m))
+ if (is_castle(m))
{
st->key = key;
do_castle_move(m);
}
Color us = side_to_move();
- Color them = opposite_color(us);
+ Color them = flip(us);
Square from = move_from(m);
Square to = move_to(m);
- bool ep = move_is_ep(m);
- bool pm = move_is_promotion(m);
+ bool ep = is_enpassant(m);
+ bool pm = is_promotion(m);
Piece piece = piece_on(from);
- PieceType pt = piece_type(piece);
- PieceType capture = ep ? PAWN : piece_type(piece_on(to));
+ PieceType pt = type_of(piece);
+ PieceType capture = ep ? PAWN : type_of(piece_on(to));
- assert(piece_color(piece_on(from)) == us);
- assert(piece_color(piece_on(to)) == them || square_is_empty(to));
+ assert(color_of(piece_on(from)) == us);
+ assert(color_of(piece_on(to)) == them || square_is_empty(to));
assert(!(ep || pm) || piece == make_piece(us, PAWN));
assert(!pm || relative_rank(us, to) == RANK_8);
// Move the piece
Bitboard move_bb = make_move_bb(from, to);
- do_move_bb(&(byColorBB[us]), move_bb);
- do_move_bb(&(byTypeBB[pt]), move_bb);
- do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
+ do_move_bb(&byColorBB[us], move_bb);
+ do_move_bb(&byTypeBB[pt], move_bb);
+ do_move_bb(&byTypeBB[0], move_bb); // HACK: byTypeBB[0] == occupied squares
board[to] = board[from];
board[from] = PIECE_NONE;
// Set en passant square, only if moved pawn can be captured
if ((to ^ from) == 16)
{
- if (attacks_from<PAWN>(from + (us == WHITE ? DELTA_N : DELTA_S), us) & pieces(PAWN, them))
+ if (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(PAWN, them))
{
st->epSquare = Square((int(from) + int(to)) / 2);
key ^= zobEp[st->epSquare];
assert(promotion >= KNIGHT && promotion <= QUEEN);
// Insert promoted piece instead of pawn
- clear_bit(&(byTypeBB[PAWN]), to);
- set_bit(&(byTypeBB[promotion]), to);
+ clear_bit(&byTypeBB[PAWN], to);
+ set_bit(&byTypeBB[promotion], to);
board[to] = make_piece(us, promotion);
// Update piece counts
}
// Finish
- sideToMove = opposite_color(sideToMove);
+ sideToMove = flip(sideToMove);
st->value += (sideToMove == WHITE ? TempoValue : -TempoValue);
assert(is_ok());
{
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);
+ assert(relative_rank(flip(them), to) == RANK_6);
assert(piece_on(to) == PIECE_NONE);
assert(piece_on(capsq) == make_piece(them, PAWN));
st->npMaterial[them] -= PieceValueMidgame[capture];
// Remove captured piece
- clear_bit(&(byColorBB[them]), capsq);
- clear_bit(&(byTypeBB[capture]), capsq);
- clear_bit(&(byTypeBB[0]), capsq);
+ clear_bit(&byColorBB[them], capsq);
+ clear_bit(&byTypeBB[capture], capsq);
+ clear_bit(&byTypeBB[0], capsq);
// Update hash key
key ^= zobrist[them][capture][capsq];
void Position::do_castle_move(Move m) {
- assert(move_is_ok(m));
- assert(move_is_castle(m));
+ assert(is_ok(m));
+ assert(is_castle(m));
Color us = side_to_move();
- Color them = opposite_color(us);
-
- // Reset capture field
- st->capturedType = PIECE_TYPE_NONE;
+ Color them = flip(us);
// Find source squares for king and rook
Square kfrom = move_from(m);
- Square rfrom = move_to(m); // HACK: See comment at beginning of function
+ Square rfrom = move_to(m);
Square kto, rto;
assert(piece_on(kfrom) == make_piece(us, KING));
{
kto = relative_square(us, SQ_G1);
rto = relative_square(us, SQ_F1);
- } else { // O-O-O
+ }
+ else // O-O-O
+ {
kto = relative_square(us, SQ_C1);
rto = relative_square(us, SQ_D1);
}
- // Remove pieces from source squares:
- clear_bit(&(byColorBB[us]), kfrom);
- clear_bit(&(byTypeBB[KING]), kfrom);
- clear_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
- clear_bit(&(byColorBB[us]), rfrom);
- clear_bit(&(byTypeBB[ROOK]), rfrom);
- clear_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
-
- // Put pieces on destination squares:
- set_bit(&(byColorBB[us]), kto);
- set_bit(&(byTypeBB[KING]), kto);
- set_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
- set_bit(&(byColorBB[us]), rto);
- set_bit(&(byTypeBB[ROOK]), rto);
- set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
-
- // Update board array
+ // Remove pieces from source squares
+ clear_bit(&byColorBB[us], kfrom);
+ clear_bit(&byTypeBB[KING], kfrom);
+ clear_bit(&byTypeBB[0], kfrom);
+ clear_bit(&byColorBB[us], rfrom);
+ clear_bit(&byTypeBB[ROOK], rfrom);
+ clear_bit(&byTypeBB[0], rfrom);
+
+ // Put pieces on destination squares
+ set_bit(&byColorBB[us], kto);
+ set_bit(&byTypeBB[KING], kto);
+ set_bit(&byTypeBB[0], kto);
+ set_bit(&byColorBB[us], rto);
+ set_bit(&byTypeBB[ROOK], rto);
+ set_bit(&byTypeBB[0], rto);
+
+ // Update board
Piece king = make_piece(us, KING);
Piece rook = make_piece(us, ROOK);
board[kfrom] = board[rfrom] = PIECE_NONE;
// Update piece lists
pieceList[us][KING][index[kfrom]] = kto;
pieceList[us][ROOK][index[rfrom]] = rto;
- int tmp = index[rfrom]; // In Chess960 could be rto == kfrom
+ int tmp = index[rfrom]; // In Chess960 could be kto == rfrom
index[kto] = index[kfrom];
index[rto] = tmp;
+ // Reset capture field
+ st->capturedType = PIECE_TYPE_NONE;
+
// Update incremental scores
st->value += pst_delta(king, kfrom, kto);
st->value += pst_delta(rook, rfrom, rto);
st->checkersBB = attackers_to(king_square(them)) & pieces(us);
// Finish
- sideToMove = opposite_color(sideToMove);
+ sideToMove = flip(sideToMove);
st->value += (sideToMove == WHITE ? TempoValue : -TempoValue);
assert(is_ok());
void Position::undo_move(Move m) {
- assert(is_ok());
- assert(move_is_ok(m));
+ assert(is_ok(m));
- sideToMove = opposite_color(sideToMove);
+ sideToMove = flip(sideToMove);
- if (move_is_castle(m))
+ if (is_castle(m))
{
undo_castle_move(m);
return;
}
Color us = side_to_move();
- Color them = opposite_color(us);
+ Color them = flip(us);
Square from = move_from(m);
Square to = move_to(m);
- bool ep = move_is_ep(m);
- bool pm = move_is_promotion(m);
+ bool ep = is_enpassant(m);
+ bool pm = is_promotion(m);
- PieceType pt = piece_type(piece_on(to));
+ PieceType pt = type_of(piece_on(to));
assert(square_is_empty(from));
- assert(piece_color(piece_on(to)) == us);
+ assert(color_of(piece_on(to)) == us);
assert(!pm || relative_rank(us, to) == RANK_8);
assert(!ep || to == st->previous->epSquare);
assert(!ep || relative_rank(us, to) == RANK_6);
assert(piece_on(to) == make_piece(us, promotion));
// Replace promoted piece with a pawn
- clear_bit(&(byTypeBB[promotion]), to);
- set_bit(&(byTypeBB[PAWN]), to);
+ clear_bit(&byTypeBB[promotion], to);
+ set_bit(&byTypeBB[PAWN], to);
// Update piece counts
pieceCount[us][promotion]--;
// Put the piece back at the source square
Bitboard move_bb = make_move_bb(to, from);
- do_move_bb(&(byColorBB[us]), move_bb);
- do_move_bb(&(byTypeBB[pt]), move_bb);
- do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
+ do_move_bb(&byColorBB[us], move_bb);
+ do_move_bb(&byTypeBB[pt], move_bb);
+ do_move_bb(&byTypeBB[0], move_bb); // HACK: byTypeBB[0] == occupied squares
board[from] = make_piece(us, pt);
board[to] = PIECE_NONE;
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));
// Restore the captured piece
- set_bit(&(byColorBB[them]), capsq);
- set_bit(&(byTypeBB[st->capturedType]), capsq);
- set_bit(&(byTypeBB[0]), capsq);
+ set_bit(&byColorBB[them], capsq);
+ set_bit(&byTypeBB[st->capturedType], capsq);
+ set_bit(&byTypeBB[0], capsq);
board[capsq] = make_piece(them, st->capturedType);
void Position::undo_castle_move(Move m) {
- assert(move_is_ok(m));
- assert(move_is_castle(m));
+ assert(is_ok(m));
+ assert(is_castle(m));
// When we have arrived here, some work has already been done by
- // Position::undo_move. In particular, the side to move has been switched,
+ // Position::undo_move. In particular, the side to move has been switched,
// so the code below is correct.
Color us = side_to_move();
// Find source squares for king and rook
Square kfrom = move_from(m);
- Square rfrom = move_to(m); // HACK: See comment at beginning of function
+ Square rfrom = move_to(m);
Square kto, rto;
// Find destination squares for king and rook
{
kto = relative_square(us, SQ_G1);
rto = relative_square(us, SQ_F1);
- } else { // O-O-O
+ }
+ else // O-O-O
+ {
kto = relative_square(us, SQ_C1);
rto = relative_square(us, SQ_D1);
}
assert(piece_on(kto) == make_piece(us, KING));
assert(piece_on(rto) == make_piece(us, ROOK));
- // Remove pieces from destination squares:
- clear_bit(&(byColorBB[us]), kto);
- clear_bit(&(byTypeBB[KING]), kto);
- clear_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
- clear_bit(&(byColorBB[us]), rto);
- clear_bit(&(byTypeBB[ROOK]), rto);
- clear_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
-
- // Put pieces on source squares:
- set_bit(&(byColorBB[us]), kfrom);
- set_bit(&(byTypeBB[KING]), kfrom);
- set_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
- set_bit(&(byColorBB[us]), rfrom);
- set_bit(&(byTypeBB[ROOK]), rfrom);
- set_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
+ // Remove pieces from destination squares
+ clear_bit(&byColorBB[us], kto);
+ clear_bit(&byTypeBB[KING], kto);
+ clear_bit(&byTypeBB[0], kto);
+ clear_bit(&byColorBB[us], rto);
+ clear_bit(&byTypeBB[ROOK], rto);
+ clear_bit(&byTypeBB[0], rto);
+
+ // Put pieces on source squares
+ set_bit(&byColorBB[us], kfrom);
+ set_bit(&byTypeBB[KING], kfrom);
+ set_bit(&byTypeBB[0], kfrom);
+ set_bit(&byColorBB[us], rfrom);
+ set_bit(&byTypeBB[ROOK], rfrom);
+ set_bit(&byTypeBB[0], rfrom);
// Update board
- board[rto] = board[kto] = PIECE_NONE;
- board[rfrom] = make_piece(us, ROOK);
- board[kfrom] = make_piece(us, KING);
+ Piece king = make_piece(us, KING);
+ Piece rook = make_piece(us, ROOK);
+ board[kto] = board[rto] = PIECE_NONE;
+ board[kfrom] = king;
+ board[rfrom] = rook;
// Update piece lists
pieceList[us][KING][index[kto]] = kfrom;
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
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];
st->key ^= zobSideToMove;
prefetch((char*)TT.first_entry(st->key));
- sideToMove = opposite_color(sideToMove);
+ sideToMove = flip(sideToMove);
st->epSquare = SQ_NONE;
st->rule50++;
st->pliesFromNull = 0;
st->value += (sideToMove == WHITE) ? TempoValue : -TempoValue;
+
+ assert(is_ok());
}
void Position::undo_null_move() {
- assert(is_ok());
assert(!in_check());
// Restore information from the our backup StateInfo object
st->pliesFromNull = backupSt->pliesFromNull;
// Update the necessary information
- sideToMove = opposite_color(sideToMove);
+ sideToMove = flip(sideToMove);
st->rule50--;
- st->gamePly--;
+
+ assert(is_ok());
}
int Position::see_sign(Move m) const {
- assert(move_is_ok(m));
+ assert(is_ok(m));
Square from = move_from(m);
Square to = move_to(m);
PieceType capturedType, pt;
Color stm;
- assert(move_is_ok(m));
+ assert(is_ok(m));
// As castle moves are implemented as capturing the rook, they have
// SEE == RookValueMidgame most of the times (unless the rook is under
// attack).
- if (move_is_castle(m))
+ if (is_castle(m))
return 0;
from = move_from(m);
to = move_to(m);
- capturedType = piece_type(piece_on(to));
+ capturedType = type_of(piece_on(to));
occupied = occupied_squares();
// Handle en passant moves
- if (st->epSquare == to && piece_type(piece_on(from)) == PAWN)
+ if (st->epSquare == to && type_of(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);
+ assert(type_of(piece_on(capQq)) == PAWN);
// Remove the captured pawn
clear_bit(&occupied, capQq);
attackers = attackers_to(to, occupied);
// If the opponent has no attackers we are finished
- stm = opposite_color(piece_color(piece_on(from)));
+ stm = flip(color_of(piece_on(from)));
stmAttackers = attackers & pieces(stm);
if (!stmAttackers)
return PieceValueMidgame[capturedType];
// capture with the least valuable piece. After each capture, we look for
// new X-ray attacks from behind the capturing piece.
swapList[0] = PieceValueMidgame[capturedType];
- capturedType = piece_type(piece_on(from));
+ capturedType = type_of(piece_on(from));
do {
// Locate the least valuable attacker for the side to move. The loop
// Remember the value of the capturing piece, and change the side to
// move before beginning the next iteration.
capturedType = pt;
- stm = opposite_color(stm);
+ stm = flip(stm);
stmAttackers = attackers & pieces(stm);
// Stop before processing a king capture
castleRightsMask[sq] = ALL_CASTLES;
}
sideToMove = WHITE;
- fullMoves = 1;
nodes = 0;
}
void Position::put_piece(Piece p, Square s) {
- Color c = piece_color(p);
- PieceType pt = piece_type(p);
+ Color c = color_of(p);
+ PieceType pt = type_of(p);
board[s] = p;
index[s] = pieceCount[c][pt]++;
for (Square s = SQ_A1; s <= SQ_H8; s++)
if (!square_is_empty(s))
- result ^= zobrist[piece_color(piece_on(s))][piece_type(piece_on(s))][s];
+ result ^= zobrist[color_of(piece_on(s))][type_of(piece_on(s))][s];
if (ep_square() != SQ_NONE)
result ^= zobEp[ep_square()];
// 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;
}
bool Position::is_mate() const {
- MoveStack moves[MAX_MOVES];
- return in_check() && generate<MV_LEGAL>(*this, moves) == moves;
+ return in_check() && !MoveList<MV_LEGAL>(*this).size();
}
/// startup the various arrays used to compute hash keys and the piece
/// square tables. The latter is a two-step operation: First, the white
/// halves of the tables are copied from the MgPST[][] and EgPST[][] arrays.
-/// Second, the black halves of the tables are initialized by mirroring
+/// Second, the black halves of the tables are initialized by flipping
/// and changing the sign of the corresponding white scores.
void Position::init() {
zobSideToMove = rk.rand<Key>();
zobExclusion = rk.rand<Key>();
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- for (Piece p = WP; p <= WK; p++)
- PieceSquareTable[p][s] = make_score(MgPST[p][s], EgPST[p][s]);
-
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- for (Piece p = BP; p <= BK; p++)
- PieceSquareTable[p][s] = -PieceSquareTable[p-8][flip_square(s)];
+ for (Piece p = WP; p <= WK; p++)
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ {
+ pieceSquareTable[p][s] = make_score(MgPST[p][s], EgPST[p][s]);
+ pieceSquareTable[p+8][flip(s)] = -pieceSquareTable[p][s];
+ }
}
-/// Position::flip() flips position with the white and black sides reversed. This
+/// Position::flip_me() flips position with the white and black sides reversed. This
/// is only useful for debugging especially for finding evaluation symmetry bugs.
-void Position::flip() {
-
- assert(is_ok());
+void Position::flip_me() {
// Make a copy of current position before to start changing
const Position pos(*this, threadID);
// Board
for (Square s = SQ_A1; s <= SQ_H8; s++)
if (!pos.square_is_empty(s))
- put_piece(Piece(pos.piece_on(s) ^ 8), flip_square(s));
+ put_piece(Piece(pos.piece_on(s) ^ 8), flip(s));
// Side to move
- sideToMove = opposite_color(pos.side_to_move());
+ sideToMove = flip(pos.side_to_move());
// Castling rights
if (pos.can_castle(WHITE_OO))
- set_castle(BLACK_OO, king_square(BLACK), flip_square(pos.castle_rook_square(WHITE_OO)));
+ set_castle(BLACK_OO, king_square(BLACK), flip(pos.castle_rook_square(WHITE_OO)));
if (pos.can_castle(WHITE_OOO))
- set_castle(BLACK_OOO, king_square(BLACK), flip_square(pos.castle_rook_square(WHITE_OOO)));
+ set_castle(BLACK_OOO, king_square(BLACK), flip(pos.castle_rook_square(WHITE_OOO)));
if (pos.can_castle(BLACK_OO))
- set_castle(WHITE_OO, king_square(WHITE), flip_square(pos.castle_rook_square(BLACK_OO)));
+ set_castle(WHITE_OO, king_square(WHITE), flip(pos.castle_rook_square(BLACK_OO)));
if (pos.can_castle(BLACK_OOO))
- set_castle(WHITE_OOO, king_square(WHITE), flip_square(pos.castle_rook_square(BLACK_OOO)));
+ set_castle(WHITE_OOO, king_square(WHITE), flip(pos.castle_rook_square(BLACK_OOO)));
// En passant square
if (pos.st->epSquare != SQ_NONE)
- st->epSquare = flip_square(pos.st->epSquare);
+ st->epSquare = flip(pos.st->epSquare);
// Checkers
- find_checkers();
+ st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(flip(sideToMove));
// Hash keys
st->key = compute_key();
{
int kingCount[2] = {0, 0};
for (Square s = SQ_A1; s <= SQ_H8; s++)
- if (piece_type(piece_on(s)) == KING)
- kingCount[piece_color(piece_on(s))]++;
+ if (type_of(piece_on(s)) == KING)
+ kingCount[color_of(piece_on(s))]++;
if (kingCount[0] != 1 || kingCount[1] != 1)
return false;
if (debugKingCapture)
{
Color us = side_to_move();
- Color them = opposite_color(us);
+ Color them = flip(us);
Square ksq = king_square(them);
if (attackers_to(ksq) & pieces(us))
return false;