#include <cassert>
#include <cstring>
#include <fstream>
-#include <map>
#include <iostream>
#include <sstream>
#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 Position::PieceValueMidgame[17] = {
+const Value PieceValueMidgame[17] = {
VALUE_ZERO,
PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
- RookValueMidgame, QueenValueMidgame, VALUE_ZERO,
- VALUE_ZERO, VALUE_ZERO,
+ RookValueMidgame, QueenValueMidgame,
+ VALUE_ZERO, VALUE_ZERO, VALUE_ZERO,
PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
RookValueMidgame, QueenValueMidgame
};
-const Value Position::PieceValueEndgame[17] = {
+const Value PieceValueEndgame[17] = {
VALUE_ZERO,
PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
- RookValueEndgame, QueenValueEndgame, VALUE_ZERO,
- VALUE_ZERO, VALUE_ZERO,
+ RookValueEndgame, QueenValueEndgame,
+ VALUE_ZERO, VALUE_ZERO, VALUE_ZERO,
PawnValueEndgame, KnightValueEndgame, BishopValueEndgame,
RookValueEndgame, QueenValueEndgame
};
-// Material values array used by SEE, indexed by PieceType
-const Value Position::seeValues[] = {
- VALUE_ZERO,
- PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
- RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10
-};
-
namespace {
// Bonus for having the side to move (modified by Joona Kiiski)
const Score TempoValue = make_score(48, 22);
- struct PieceLetters : public std::map<char, Piece> {
-
- PieceLetters() {
-
- operator[]('K') = WK; operator[]('k') = BK;
- operator[]('Q') = WQ; operator[]('q') = BQ;
- operator[]('R') = WR; operator[]('r') = BR;
- operator[]('B') = WB; operator[]('b') = BB;
- operator[]('N') = WN; operator[]('n') = BN;
- operator[]('P') = WP; operator[]('p') = BP;
- operator[](' ') = PIECE_NONE;
- operator[]('.') = PIECE_NONE_DARK_SQ;
- }
-
- char from_piece(Piece p) const {
-
- std::map<char, Piece>::const_iterator it;
- for (it = begin(); it != end(); ++it)
- if (it->second == p)
- return it->first;
-
- assert(false);
- return 0;
- }
- };
-
- PieceLetters pieceLetters;
+ // To convert a Piece to and from a FEN char
+ const string PieceToChar(".PNBRQK pnbrqk ");
}
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);
- ksq = pos.king_square(them);
- dcCandidates = pos.discovered_check_candidates(us);
+ pinned = pos.pinned_pieces();
+ dcCandidates = pos.discovered_check_candidates();
- checkSq[PAWN] = pos.attacks_from<PAWN>(ksq, them);
+ checkSq[PAWN]
= pos.attacks_from<PAWN>(ksq, them);
checkSq[KNIGHT] = pos.attacks_from<KNIGHT>(ksq);
checkSq[BISHOP] = pos.attacks_from<BISHOP>(ksq);
- checkSq[ROOK] = pos.attacks_from<ROOK>(ksq);
- checkSq[QUEEN] = checkSq[BISHOP] | checkSq[ROOK];
- checkSq[KING] = EmptyBoardBB;
+ checkSq[ROOK] = pos.attacks_from<ROOK>(ksq);
+ checkSq[QUEEN] = checkSq[BISHOP] | checkSq[ROOK];
+ checkSq[KING] = EmptyBoardBB;
}
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) {
startState = *st;
st = &startState;
- st->previous = NULL; // as a safe guard
+ st->previous = NULL; // As a safe guard
}
/// 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.
6) Fullmove number: The number of the full move. It starts at 1, and is incremented after Black's move.
*/
- char token;
- int hmc, fmn;
- std::istringstream ss(fen);
+ char col, row, token;
+ size_t p;
Square sq = SQ_A8;
+ std::istringstream fen(fenStr);
clear();
+ fen >> std::noskipws;
- // 1. Piece placement field
- while (ss.get(token) && token != ' ')
+ // 1. Piece placement
+ while ((fen >> token) && !isspace(token))
{
- if (pieceLetters.find(token) != pieceLetters.end())
+ if (token == '/')
+ sq -= Square(16); // Jump back of 2 rows
+
+ else if (isdigit(token))
+ sq += Square(token - '0'); // Skip the given number of files
+
+ else if ((p = PieceToChar.find(token)) != string::npos)
{
- put_piece(pieceLetters[token], sq);
+ put_piece(Piece(p), sq);
sq++;
}
- else if (isdigit(token))
- sq += Square(token - '0'); // Skip the given number of files
- else if (token == '/')
- sq -= SQ_A3; // Jump back of 2 rows
- else
- goto incorrect_fen;
}
// 2. Active color
- if (!ss.get(token) || (token != 'w' && token != 'b'))
- goto incorrect_fen;
-
+ fen >> token;
sideToMove = (token == 'w' ? WHITE : BLACK);
-
- if (!ss.get(token) || token != ' ')
- goto incorrect_fen;
+ fen >> token;
// 3. Castling availability
- while (ss.get(token) && token != ' ')
- if (!set_castling_rights(token))
- goto incorrect_fen;
-
- // 4. En passant square
- char col, row;
- if ( (ss.get(col) && (col >= 'a' && col <= 'h'))
- && (ss.get(row) && (row == '3' || row == '6')))
- {
- st->epSquare = make_square(file_from_char(col), rank_from_char(row));
+ while ((fen >> token) && !isspace(token))
+ set_castling_rights(token);
- // Ignore if no capture is possible
+ // 4. En passant square. Ignore if no pawn capture is possible
+ 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);
+
if (!(attacks_from<PAWN>(st->epSquare, them) & pieces(PAWN, sideToMove)))
st->epSquare = SQ_NONE;
}
- // 5. Halfmove clock
- if (ss >> hmc)
- st->rule50 = hmc;
-
- // 6. Fullmove number
- if (ss >> fmn)
- startPosPlyCounter = (fmn - 1) * 2 + int(sideToMove == BLACK);
+ // 5-6. Halfmove clock and fullmove number
+ fen >> std::skipws >> st->rule50 >> fullMoves;
// Various initialisations
- castleRightsMask[make_square(initialKFile, RANK_1)] ^= WHITE_OO | WHITE_OOO;
- castleRightsMask[make_square(initialKFile, RANK_8)] ^= BLACK_OO | BLACK_OOO;
- castleRightsMask[make_square(initialKRFile, RANK_1)] ^= WHITE_OO;
- castleRightsMask[make_square(initialKRFile, RANK_8)] ^= BLACK_OO;
- castleRightsMask[make_square(initialQRFile, RANK_1)] ^= WHITE_OOO;
- castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO;
-
chess960 = isChess960;
- find_checkers();
+ st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(opposite_color(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);
- return;
-incorrect_fen:
- cout << "Error in FEN string: " << fen << endl;
+ assert(is_ok());
+}
+
+
+/// Position::set_castle() is an helper function used to set
+/// correct castling related flags.
+
+void Position::set_castle(int f, Square ksq, Square rsq) {
+
+ st->castleRights |= f;
+ castleRightsMask[ksq] ^= f;
+ castleRightsMask[rsq] ^= f;
+ castleRookSquare[f] = rsq;
}
/// associated with the castling right, the traditional castling tag will be replaced
/// by the file letter of the involved rook as for the Shredder-FEN.
-bool Position::set_castling_rights(char token) {
+void Position::set_castling_rights(char token) {
+
+ Color c = islower(token) ? BLACK : WHITE;
- Color c = token >= 'a' ? BLACK : WHITE;
- Square sqA = (c == WHITE ? SQ_A1 : SQ_A8);
- Square sqH = (c == WHITE ? SQ_H1 : SQ_H8);
- Piece rook = (c == WHITE ? WR : BR);
+ Square sqA = relative_square(c, SQ_A1);
+ Square sqH = relative_square(c, SQ_H1);
+ Square rsq, ksq = king_square(c);
- initialKFile = square_file(king_square(c));
token = char(toupper(token));
if (token == 'K')
- {
- for (Square sq = sqH; sq >= sqA; sq--)
- if (piece_on(sq) == rook)
- {
- do_allow_oo(c);
- initialKRFile = square_file(sq);
- break;
- }
- }
+ for (rsq = sqH; piece_on(rsq) != make_piece(c, ROOK); rsq--) {}
+
else if (token == 'Q')
- {
- for (Square sq = sqA; sq <= sqH; sq++)
- if (piece_on(sq) == rook)
- {
- do_allow_ooo(c);
- initialQRFile = square_file(sq);
- break;
- }
- }
+ for (rsq = sqA; piece_on(rsq) != make_piece(c, ROOK); rsq++) {}
+
else if (token >= 'A' && token <= 'H')
- {
- File rookFile = File(token - 'A') + FILE_A;
- if (rookFile < initialKFile)
- {
- do_allow_ooo(c);
- initialQRFile = rookFile;
- }
- else
- {
- do_allow_oo(c);
- initialKRFile = rookFile;
- }
- }
- else
- return token == '-';
+ rsq = make_square(File(token - 'A'), relative_rank(c, RANK_1));
- return true;
+ else return;
+
+ if (square_file(rsq) < square_file(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 = '0';
+ int emptyCnt;
- for (Rank rank = RANK_8; rank >= RANK_1; rank--, fen += '/')
+ for (Rank rank = RANK_8; rank >= RANK_1; rank--)
{
+ emptyCnt = 0;
+
for (File file = FILE_A; file <= FILE_H; file++)
{
sq = make_square(file, rank);
- if (square_is_occupied(sq))
+ if (!square_is_empty(sq))
{
- if (emptyCnt != '0')
+ if (emptyCnt)
{
- fen += emptyCnt;
- emptyCnt = '0';
+ fen << emptyCnt;
+ emptyCnt = 0;
}
- fen += pieceLetters.from_piece(piece_on(sq));
- } else
+ fen << PieceToChar[piece_on(sq)];
+ }
+ else
emptyCnt++;
}
- if (emptyCnt != '0')
- {
- fen += emptyCnt;
- emptyCnt = '0';
- }
+ 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_kingside(WHITE))
- fen += chess960 ? char(toupper(file_to_char(initialKRFile))) : 'K';
+ if (can_castle(WHITE_OO))
+ fen << (chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OO))))) : 'K');
- if (can_castle_queenside(WHITE))
- fen += chess960 ? char(toupper(file_to_char(initialQRFile))) : 'Q';
+ if (can_castle(WHITE_OOO))
+ fen << (chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OOO))))) : 'Q');
- if (can_castle_kingside(BLACK))
- fen += chess960 ? file_to_char(initialKRFile) : 'k';
+ if (can_castle(BLACK_OO))
+ fen << (chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OO))) : 'k');
- if (can_castle_queenside(BLACK))
- fen += chess960 ? file_to_char(initialQRFile) : 'q';
+ if (can_castle(BLACK_OOO))
+ fen << (chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OOO))) : 'q');
} else
- fen += '-';
+ fen << '-';
+
+ fen << (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square()))
+ << " " << st->rule50 << " " << fullMoves;
- fen += (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square()));
- return fen;
+ return fen.str();
}
if (move)
{
Position p(*this, thread());
- string dd = (color_of_piece_on(move_from(move)) == BLACK ? ".." : "");
+ string dd = (sideToMove == BLACK ? ".." : "");
cout << "\nMove is: " << dd << move_to_san(p, move);
}
if (piece == PIECE_NONE && square_color(sq) == DARK)
piece = PIECE_NONE_DARK_SQ;
- char c = (color_of_piece_on(sq) == BLACK ? '=' : ' ');
- cout << c << pieceLetters.from_piece(piece) << c << '|';
+ char c = (piece_color(piece_on(sq)) == BLACK ? '=' : ' ');
+ cout << c << PieceToChar[piece] << c << '|';
}
}
cout << dottedLine << "Fen is: " << to_fen() << "\nKey is: " << st->key << endl;
/// 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 Position::hidden_checkers() const {
- Bitboard result = EmptyBoardBB;
- Bitboard pinners = pieces_of_color(FindPinned ? opposite_color(c) : c);
+ // 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));
- // Pinned pieces protect our king, dicovery checks attack
- // the enemy king.
- Square ksq = king_square(FindPinned ? c : opposite_color(c));
-
- // 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_of_color(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
| (attacks_from<KING>(s) & pieces(KING));
}
+Bitboard Position::attackers_to(Square s, Bitboard occ) const {
+
+ return (attacks_from<PAWN>(s, BLACK) & pieces(PAWN, WHITE))
+ | (attacks_from<PAWN>(s, WHITE) & pieces(PAWN, BLACK))
+ | (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
+ | (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN))
+ | (bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN))
+ | (attacks_from<KING>(s) & pieces(KING));
+}
+
/// Position::attacks_from() computes a bitboard of all attacks
/// of a given piece put in a given square.
Bitboard occ, xray;
Square f = move_from(m), t = move_to(m);
- assert(square_is_occupied(f));
+ assert(!square_is_empty(f));
if (bit_is_set(attacks_from(piece_on(f), t), s))
return true;
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_of_color(color_of_piece_on(f));
+ & pieces(piece_color(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_of_color(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(pinned == pinned_pieces());
- // Castling moves are checked for legality during move generation.
- if (move_is_castle(m))
- return true;
+ Color us = side_to_move();
+ Square from = move_from(m);
+
+ assert(piece_color(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
+ // 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))
{
- Color us = side_to_move();
Color them = opposite_color(us);
- Square from = move_from(m);
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();
&& !(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them));
}
- Color us = side_to_move();
- Square from = move_from(m);
-
- assert(color_of_piece_on(from) == us);
- assert(piece_on(king_square(us)) == make_piece(us, KING));
-
// 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(move_to(m)) & pieces_of_color(opposite_color(us)));
+ // 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)));
// 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::pl_move_is_evasion() tests whether a pseudo-legal move is a legal evasion
-
-bool Position::pl_move_is_evasion(Move m, Bitboard pinned) const
-{
- assert(is_check());
-
- Color us = side_to_move();
- Square from = move_from(m);
- Square to = move_to(m);
-
- // King moves and en-passant captures are verified in pl_move_is_legal()
- if (type_of_piece_on(from) == KING || move_is_ep(m))
- return pl_move_is_legal(m, pinned);
-
- Bitboard target = checkers();
- Square checksq = pop_1st_bit(&target);
-
- if (target) // double check ?
- return false;
-
- // Our move must be a blocking evasion or a capture of the checking piece
- target = squares_between(checksq, king_square(us)) | checkers();
- return bit_is_set(target, to) && pl_move_is_legal(m, pinned);
-}
-
-/// Position::move_is_legal() takes a position and a (not necessarily pseudo-legal)
-/// move and tests whether the move is legal. This version is not very fast and
-/// should be used only in non time-critical paths.
+/// Position::move_is_legal() takes a move and tests whether the move
+/// is legal. This version is not very fast and should be used only
+/// in non time-critical paths.
bool Position::move_is_legal(const Move m) const {
- MoveStack mlist[MAX_MOVES];
- MoveStack *cur, *last = generate<MV_PSEUDO_LEGAL>(*this, mlist);
-
- for (cur = mlist; cur != last; cur++)
- if (cur->move == m)
- return pl_move_is_legal(m, pinned_pieces(sideToMove));
+ for (MoveList<MV_LEGAL> ml(*this); !ml.end(); ++ml)
+ if (ml.move() == m)
+ return true;
return false;
}
-/// Fast version of Position::move_is_legal() that takes a position a move and
-/// a bitboard of pinned pieces as input, and tests whether the move is legal.
+/// 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.
-bool Position::move_is_legal(const Move m, Bitboard pinned) const {
-
- assert(is_ok());
- assert(pinned == pinned_pieces(sideToMove));
+bool Position::move_is_pl(const Move m) const {
Color us = sideToMove;
Color them = opposite_color(sideToMove);
if (move_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)
+ return false;
+
// If the from square is not occupied by a piece belonging to the side to
// move, the move is obviously not legal.
- if (color_of_piece(pc) != us)
+ if (pc == PIECE_NONE || piece_color(pc) != us)
return false;
// The destination square cannot be occupied by a friendly piece
- if (color_of_piece_on(to) == us)
+ if (piece_color(piece_on(to)) == us)
return false;
// Handle the special case of a pawn move
- if (type_of_piece(pc) == PAWN)
+ if (piece_type(pc) == PAWN)
{
// Move direction must be compatible with pawn color
int direction = to - from;
case DELTA_SE:
// Capture. The destination square must be occupied by an enemy
// piece (en passant captures was handled earlier).
- if (color_of_piece_on(to) != them)
- return false;
- break;
+ if (piece_color(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)
+ return false;
+ break;
case DELTA_N:
case DELTA_S:
// Pawn push. The destination square must be empty.
- if (!square_is_empty(to))
- return false;
- break;
+ if (!square_is_empty(to))
+ return false;
+ break;
case DELTA_NN:
// Double white pawn push. The destination square must be on the fourth
|| !square_is_empty(to)
|| !square_is_empty(from + DELTA_N))
return false;
- break;
+ break;
case DELTA_SS:
// 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
- || !square_is_empty(to)
- || !square_is_empty(from + DELTA_S))
- return false;
- break;
+ if ( square_rank(to) != RANK_5
+ || !square_is_empty(to)
+ || !square_is_empty(from + DELTA_S))
+ return false;
+ break;
default:
return false;
else if (!bit_is_set(attacks_from(pc, from), to))
return false;
- // The move is pseudo-legal, check if it is also legal
- return is_check() ? pl_move_is_evasion(m, pinned) : pl_move_is_legal(m, pinned);
-}
-
+ if (in_check())
+ {
+ // 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)
+ {
+ Bitboard b = occupied_squares();
+ clear_bit(&b, from);
+ if (attackers_to(move_to(m), b) & pieces(opposite_color(us)))
+ return false;
+ }
+ else
+ {
+ Bitboard target = checkers();
+ Square checksq = pop_1st_bit(&target);
-/// Position::move_is_check() tests whether a pseudo-legal move is a check
+ if (target) // double check ? In this case a king move is required
+ return false;
-bool Position::move_is_check(Move m) const {
+ // Our move must be a blocking evasion or a capture of the checking piece
+ target = squares_between(checksq, king_square(us)) | checkers();
+ if (!bit_is_set(target, move_to(m)))
+ return false;
+ }
+ }
- return move_is_check(m, CheckInfo(*this));
+ return true;
}
-bool Position::move_is_check(Move m, const CheckInfo& ci) const {
- assert(is_ok());
+/// Position::move_gives_check() tests whether a pseudo-legal move is a check
+
+bool Position::move_gives_check(Move m, const CheckInfo& ci) const {
+
assert(move_is_ok(m));
- assert(ci.dcCandidates == discovered_check_candidates(side_to_move()));
- assert(color_of_piece_on(move_from(m)) == side_to_move());
- assert(piece_on(ci.ksq) == make_piece(opposite_color(side_to_move()), KING));
+ assert(ci.dcCandidates == discovered_check_candidates());
+ assert(piece_color(piece_on(move_from(m))) == side_to_move());
Square from = move_from(m);
Square to = move_to(m);
- PieceType pt = type_of_piece_on(from);
+ PieceType pt = piece_type(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, ci.ksq))
+ || !squares_aligned(from, to, king_square(opposite_color(side_to_move()))))
return true;
}
Color us = side_to_move();
Bitboard b = occupied_squares();
+ Square ksq = king_square(opposite_color(us));
// Promotion with check ?
if (move_is_promotion(m))
{
clear_bit(&b, from);
- switch (move_promotion_piece(m))
+ switch (promotion_piece_type(m))
{
case KNIGHT:
- return bit_is_set(attacks_from<KNIGHT>(to), ci.ksq);
+ return bit_is_set(attacks_from<KNIGHT>(to), ksq);
case BISHOP:
- return bit_is_set(bishop_attacks_bb(to, b), ci.ksq);
+ return bit_is_set(bishop_attacks_bb(to, b), ksq);
case ROOK:
- return bit_is_set(rook_attacks_bb(to, b), ci.ksq);
+ return bit_is_set(rook_attacks_bb(to, b), ksq);
case QUEEN:
- return bit_is_set(queen_attacks_bb(to, b), ci.ksq);
+ return bit_is_set(queen_attacks_bb(to, b), ksq);
default:
assert(false);
}
clear_bit(&b, from);
clear_bit(&b, capsq);
set_bit(&b, to);
- return (rook_attacks_bb(ci.ksq, b) & pieces(ROOK, QUEEN, us))
- ||(bishop_attacks_bb(ci.ksq, b) & pieces(BISHOP, QUEEN, us));
+ return (rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, us))
+ ||(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, us));
}
// Castling with check ?
clear_bit(&b, rfrom);
set_bit(&b, rto);
set_bit(&b, kto);
- return bit_is_set(rook_attacks_bb(rto, b), ci.ksq);
+ return bit_is_set(rook_attacks_bb(rto, b), ksq);
}
return false;
}
-/// 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.
+/// 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.
if (st->rule50 == 0)
st->gamePly = 0;
- // Update the number of plies played from the starting position
- startPosPlyCounter++;
-
// Our StateInfo newSt is about going out of scope so copy
- // its content inside pos before it disappears.
+ // its content before it disappears.
detach();
+
+ assert(is_ok());
}
+
/// 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.
+/// 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, move_is_check(m, ci));
+ do_move(m, newSt, ci, move_gives_check(m, ci));
}
void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) {
- assert(is_ok());
assert(move_is_ok(m));
assert(&newSt != st);
bool pm = move_is_promotion(m);
Piece piece = piece_on(from);
- PieceType pt = type_of_piece(piece);
- PieceType capture = ep ? PAWN : type_of_piece_on(to);
+ PieceType pt = piece_type(piece);
+ PieceType capture = ep ? PAWN : piece_type(piece_on(to));
- assert(color_of_piece_on(from) == us);
- assert(color_of_piece_on(to) == them || square_is_empty(to));
+ assert(piece_color(piece_on(from)) == us);
+ assert(piece_color(piece_on(to)) == them || square_is_empty(to));
assert(!(ep || pm) || piece == make_piece(us, PAWN));
assert(!pm || relative_rank(us, to) == RANK_8);
st->epSquare = SQ_NONE;
}
- // Update castle rights, try to shortcut a common case
- int cm = castleRightsMask[from] & castleRightsMask[to];
- if (cm != ALL_CASTLES && ((cm & st->castleRights) != st->castleRights))
+ // Update castle rights if needed
+ if ( st->castleRights != CASTLES_NONE
+ && (castleRightsMask[from] & castleRightsMask[to]) != ALL_CASTLES)
{
key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[from];
- st->castleRights &= castleRightsMask[to];
+ st->castleRights &= castleRightsMask[from] & castleRightsMask[to];
key ^= zobCastle[st->castleRights];
}
// 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];
if (pm) // promotion ?
{
- PieceType promotion = move_promotion_piece(m);
+ PieceType promotion = promotion_piece_type(m);
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
st->pawnKey ^= zobrist[us][PAWN][to];
// Partially revert and update incremental scores
- st->value -= pst(us, PAWN, to);
- st->value += pst(us, promotion, to);
+ st->value -= pst(make_piece(us, PAWN), to);
+ st->value += pst(make_piece(us, promotion), to);
// Update material
st->npMaterial[us] += PieceValueMidgame[promotion];
}
// Prefetch pawn and material hash tables
- ThreadsMgr[threadID].pawnTable.prefetch(st->pawnKey);
- ThreadsMgr[threadID].materialTable.prefetch(st->materialKey);
+ Threads[threadID].pawnTable.prefetch(st->pawnKey);
+ Threads[threadID].materialTable.prefetch(st->materialKey);
// Update incremental scores
st->value += pst_delta(piece, from, to);
if (moveIsCheck)
{
if (ep | pm)
- st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us);
+ st->checkersBB = attackers_to(king_square(them)) & pieces(us);
else
{
// Direct checks
if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
{
if (pt != ROOK)
- st->checkersBB |= (attacks_from<ROOK>(ci.ksq) & pieces(ROOK, QUEEN, us));
+ st->checkersBB |= (attacks_from<ROOK>(king_square(them)) & pieces(ROOK, QUEEN, us));
if (pt != BISHOP)
- st->checkersBB |= (attacks_from<BISHOP>(ci.ksq) & pieces(BISHOP, QUEEN, us));
+ st->checkersBB |= (attacks_from<BISHOP>(king_square(them)) & pieces(BISHOP, QUEEN, us));
}
}
}
{
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);
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];
// Update incremental scores
- st->value -= pst(them, capture, capsq);
+ st->value -= pst(make_piece(them, capture), capsq);
// Update piece count
pieceCount[them][capture]--;
Color us = side_to_move();
Color them = opposite_color(us);
- // Reset capture field
- st->capturedType = PIECE_TYPE_NONE;
-
// 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->rule50 = 0;
// Update checkers BB
- st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us);
+ st->checkersBB = attackers_to(king_square(them)) & pieces(us);
// Finish
sideToMove = opposite_color(sideToMove);
void Position::undo_move(Move m) {
- assert(is_ok());
assert(move_is_ok(m));
sideToMove = opposite_color(sideToMove);
bool ep = move_is_ep(m);
bool pm = move_is_promotion(m);
- PieceType pt = type_of_piece_on(to);
+ PieceType pt = piece_type(piece_on(to));
assert(square_is_empty(from));
- assert(color_of_piece_on(to) == us);
+ assert(piece_color(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);
if (pm) // promotion ?
{
- PieceType promotion = move_promotion_piece(m);
+ PieceType promotion = promotion_piece_type(m);
pt = PAWN;
assert(promotion >= KNIGHT && promotion <= QUEEN);
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);
assert(move_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(!is_check());
+ assert(!in_check());
// Back up the information necessary to undo the null move to the supplied
// StateInfo object.
st->rule50++;
st->pliesFromNull = 0;
st->value += (sideToMove == WHITE) ? TempoValue : -TempoValue;
+
+ assert(is_ok());
}
void Position::undo_null_move() {
- assert(is_ok());
- assert(!is_check());
+ assert(!in_check());
// Restore information from the our backup StateInfo object
StateInfo* backupSt = st->previous;
sideToMove = opposite_color(sideToMove);
st->rule50--;
st->gamePly--;
+
+ assert(is_ok());
}
/// move, and one which takes a 'from' and a 'to' square. The function does
/// not yet understand promotions captures.
-int Position::see(Move m) const {
-
- assert(move_is_ok(m));
- return see(move_from(m), move_to(m));
-}
-
int Position::see_sign(Move m) const {
assert(move_is_ok(m));
// Early return if SEE cannot be negative because captured piece value
// is not less then capturing one. Note that king moves always return
// here because king midgame value is set to 0.
- if (midgame_value_of_piece_on(to) >= midgame_value_of_piece_on(from))
+ if (piece_value_midgame(piece_on(to)) >= piece_value_midgame(piece_on(from)))
return 1;
- return see(from, to);
+ return see(m);
}
-int Position::see(Square from, Square to) const {
+int Position::see(Move m) const {
+ Square from, to;
Bitboard occupied, attackers, stmAttackers, b;
int swapList[32], slIndex = 1;
PieceType capturedType, pt;
Color stm;
- assert(square_is_ok(from));
- assert(square_is_ok(to));
-
- capturedType = type_of_piece_on(to);
+ assert(move_is_ok(m));
- // King cannot be recaptured
- if (capturedType == KING)
- return seeValues[capturedType];
+ // 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))
+ return 0;
+ from = move_from(m);
+ to = move_to(m);
+ capturedType = piece_type(piece_on(to));
occupied = occupied_squares();
// Handle en passant moves
- if (st->epSquare == to && type_of_piece_on(from) == PAWN)
+ 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(type_of_piece_on(capQq) == PAWN);
+ assert(piece_type(piece_on(capQq)) == PAWN);
// Remove the captured pawn
clear_bit(&occupied, capQq);
// Find all attackers to the destination square, with the moving piece
// removed, but possibly an X-ray attacker added behind it.
clear_bit(&occupied, from);
- attackers = (rook_attacks_bb(to, occupied) & pieces(ROOK, QUEEN))
- | (bishop_attacks_bb(to, occupied)& pieces(BISHOP, QUEEN))
- | (attacks_from<KNIGHT>(to) & pieces(KNIGHT))
- | (attacks_from<KING>(to) & pieces(KING))
- | (attacks_from<PAWN>(to, WHITE) & pieces(PAWN, BLACK))
- | (attacks_from<PAWN>(to, BLACK) & pieces(PAWN, WHITE));
+ attackers = attackers_to(to, occupied);
// If the opponent has no attackers we are finished
- stm = opposite_color(color_of_piece_on(from));
- stmAttackers = attackers & pieces_of_color(stm);
+ stm = opposite_color(piece_color(piece_on(from)));
+ stmAttackers = attackers & pieces(stm);
if (!stmAttackers)
- return seeValues[capturedType];
+ return PieceValueMidgame[capturedType];
// The destination square is defended, which makes things rather more
// difficult to compute. We proceed by building up a "swap list" containing
// destination square, where the sides alternately capture, and always
// capture with the least valuable piece. After each capture, we look for
// new X-ray attacks from behind the capturing piece.
- swapList[0] = seeValues[capturedType];
- capturedType = type_of_piece_on(from);
+ swapList[0] = PieceValueMidgame[capturedType];
+ capturedType = piece_type(piece_on(from));
do {
// Locate the least valuable attacker for the side to move. The loop
// Add the new entry to the swap list
assert(slIndex < 32);
- swapList[slIndex] = -swapList[slIndex - 1] + seeValues[capturedType];
+ swapList[slIndex] = -swapList[slIndex - 1] + PieceValueMidgame[capturedType];
slIndex++;
// Remember the value of the capturing piece, and change the side to
// move before beginning the next iteration.
capturedType = pt;
stm = opposite_color(stm);
- stmAttackers = attackers & pieces_of_color(stm);
+ stmAttackers = attackers & pieces(stm);
// Stop before processing a king capture
if (capturedType == KING && stmAttackers)
st = &startState;
memset(st, 0, sizeof(StateInfo));
st->epSquare = SQ_NONE;
- startPosPlyCounter = 0;
- nodes = 0;
memset(byColorBB, 0, sizeof(Bitboard) * 2);
memset(byTypeBB, 0, sizeof(Bitboard) * 8);
memset(pieceCount, 0, sizeof(int) * 2 * 8);
memset(index, 0, sizeof(int) * 64);
- for (int i = 0; i < 64; i++)
- board[i] = PIECE_NONE;
-
for (int i = 0; i < 8; i++)
for (int j = 0; j < 16; j++)
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
+ {
+ board[sq] = PIECE_NONE;
castleRightsMask[sq] = ALL_CASTLES;
-
+ }
sideToMove = WHITE;
- initialKFile = FILE_E;
- initialKRFile = FILE_H;
- initialQRFile = FILE_A;
+ fullMoves = 1;
+ nodes = 0;
}
void Position::put_piece(Piece p, Square s) {
- Color c = color_of_piece(p);
- PieceType pt = type_of_piece(p);
+ Color c = piece_color(p);
+ PieceType pt = piece_type(p);
board[s] = p;
index[s] = pieceCount[c][pt]++;
pieceList[c][pt][index[s]] = s;
- set_bit(&(byTypeBB[pt]), s);
- set_bit(&(byColorBB[c]), s);
- set_bit(&(byTypeBB[0]), s); // HACK: byTypeBB[0] contains all occupied squares.
+ set_bit(&byTypeBB[pt], s);
+ set_bit(&byColorBB[c], s);
+ set_bit(&byTypeBB[0], s); // HACK: byTypeBB[0] contains all occupied squares.
}
Key result = zobCastle[st->castleRights];
for (Square s = SQ_A1; s <= SQ_H8; s++)
- if (square_is_occupied(s))
- result ^= zobrist[color_of_piece_on(s)][type_of_piece_on(s)][s];
+ if (!square_is_empty(s))
+ result ^= zobrist[piece_color(piece_on(s))][piece_type(piece_on(s))][s];
if (ep_square() != SQ_NONE)
result ^= zobEp[ep_square()];
Key Position::compute_material_key() const {
- int count;
Key result = 0;
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= QUEEN; pt++)
- {
- count = piece_count(c, pt);
- for (int i = 0; i < count; i++)
+ for (int i = 0, cnt = piece_count(c, pt); i < cnt; i++)
result ^= zobrist[c][pt][i];
- }
+
return result;
}
{
b = pieces(pt, c);
while (b)
- result += pst(c, pt, pop_1st_bit(&b));
+ result += pst(make_piece(c, pt), pop_1st_bit(&b));
}
result += (side_to_move() == WHITE ? TempoValue / 2 : -TempoValue / 2);
/// Position::is_draw() tests whether the position is drawn by material,
/// repetition, or the 50 moves rule. It does not detect stalemates, this
/// must be done by the search.
-
+template<bool SkipRepetition>
bool Position::is_draw() const {
// Draw by material?
return true;
// Draw by repetition?
- 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;
+ 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;
return false;
}
+// Explicit template instantiations
+template bool Position::is_draw<false>() const;
+template bool Position::is_draw<true>() const;
+
/// Position::is_mate() returns true or false depending on whether the
/// side to move is checkmated.
bool Position::is_mate() const {
- MoveStack moves[MAX_MOVES];
- return is_check() && generate<MV_LEGAL>(*this, moves) == moves;
+ return in_check() && !MoveList<MV_LEGAL>(*this).size();
}
-/// Position::init_zobrist() is a static member function which initializes at
-/// startup the various arrays used to compute hash keys.
+/// Position::init() is a static member function which initializes at
+/// 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
+/// and changing the sign of the corresponding white scores.
-void Position::init_zobrist() {
+void Position::init() {
- int i,j, k;
RKISS rk;
- for (i = 0; i < 2; i++) for (j = 0; j < 8; j++) for (k = 0; k < 64; k++)
- zobrist[i][j][k] = rk.rand<Key>();
+ for (Color c = WHITE; c <= BLACK; c++)
+ for (PieceType pt = PAWN; pt <= KING; pt++)
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ zobrist[c][pt][s] = rk.rand<Key>();
- for (i = 0; i < 64; i++)
- zobEp[i] = rk.rand<Key>();
+ for (Square s = SQ_A1; s <= SQ_H8; s++)
+ zobEp[s] = rk.rand<Key>();
- for (i = 0; i < 16; i++)
+ for (int i = 0; i < 16; i++)
zobCastle[i] = rk.rand<Key>();
zobSideToMove = rk.rand<Key>();
zobExclusion = rk.rand<Key>();
-}
-
-
-/// Position::init_piece_square_tables() initializes the piece square tables.
-/// This 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 and changing the sign of the
-/// corresponding white scores.
-
-void Position::init_piece_square_tables() {
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]);
+ 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)];
+ pieceSquareTable[p][s] = -pieceSquareTable[p-8][flip_square(s)];
}
-/// Position::flipped_copy() makes a copy of the input position, but with
-/// the white and black sides reversed. This is only useful for debugging,
-/// especially for finding evaluation symmetry bugs.
+/// Position::flip() flips position with the white and black sides reversed. This
+/// is only useful for debugging especially for finding evaluation symmetry bugs.
-void Position::flipped_copy(const Position& pos) {
+void Position::flip() {
- assert(pos.is_ok());
+ // Make a copy of current position before to start changing
+ const Position pos(*this, threadID);
clear();
threadID = pos.thread();
sideToMove = opposite_color(pos.side_to_move());
// Castling rights
- if (pos.can_castle_kingside(WHITE)) do_allow_oo(BLACK);
- if (pos.can_castle_queenside(WHITE)) do_allow_ooo(BLACK);
- if (pos.can_castle_kingside(BLACK)) do_allow_oo(WHITE);
- if (pos.can_castle_queenside(BLACK)) do_allow_ooo(WHITE);
-
- initialKFile = pos.initialKFile;
- initialKRFile = pos.initialKRFile;
- initialQRFile = pos.initialQRFile;
-
- castleRightsMask[make_square(initialKFile, RANK_1)] ^= (WHITE_OO | WHITE_OOO);
- castleRightsMask[make_square(initialKFile, RANK_8)] ^= (BLACK_OO | BLACK_OOO);
- castleRightsMask[make_square(initialKRFile, RANK_1)] ^= WHITE_OO;
- castleRightsMask[make_square(initialKRFile, RANK_8)] ^= BLACK_OO;
- castleRightsMask[make_square(initialQRFile, RANK_1)] ^= WHITE_OOO;
- castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO;
+ if (pos.can_castle(WHITE_OO))
+ set_castle(BLACK_OO, king_square(BLACK), flip_square(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)));
+ if (pos.can_castle(BLACK_OO))
+ set_castle(WHITE_OO, king_square(WHITE), flip_square(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)));
// En passant square
if (pos.st->epSquare != SQ_NONE)
st->epSquare = flip_square(pos.st->epSquare);
// Checkers
- find_checkers();
+ st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(opposite_color(sideToMove));
// Hash keys
st->key = compute_key();
if (failedStep) *failedStep = 1;
// Side to move OK?
- if (!color_is_ok(side_to_move()))
+ if (side_to_move() != WHITE && side_to_move() != BLACK)
return false;
// Are the king squares in the position correct?
if (piece_on(king_square(BLACK)) != BK)
return false;
- // Castle files OK?
- if (failedStep) (*failedStep)++;
- if (!file_is_ok(initialKRFile))
- return false;
-
- if (!file_is_ok(initialQRFile))
- return false;
-
// Do both sides have exactly one king?
if (failedStep) (*failedStep)++;
if (debugKingCount)
{
int kingCount[2] = {0, 0};
for (Square s = SQ_A1; s <= SQ_H8; s++)
- if (type_of_piece_on(s) == KING)
- kingCount[color_of_piece_on(s)]++;
+ if (piece_type(piece_on(s)) == KING)
+ kingCount[piece_color(piece_on(s))]++;
if (kingCount[0] != 1 || kingCount[1] != 1)
return false;
Color us = side_to_move();
Color them = opposite_color(us);
Square ksq = king_square(them);
- if (attackers_to(ksq) & pieces_of_color(us))
+ if (attackers_to(ksq) & pieces(us))
return false;
}
if (debugBitboards)
{
// The intersection of the white and black pieces must be empty
- if ((pieces_of_color(WHITE) & pieces_of_color(BLACK)) != EmptyBoardBB)
+ if ((pieces(WHITE) & pieces(BLACK)) != EmptyBoardBB)
return false;
// The union of the white and black pieces must be equal to all
// occupied squares
- if ((pieces_of_color(WHITE) | pieces_of_color(BLACK)) != occupied_squares())
+ if ((pieces(WHITE) | pieces(BLACK)) != occupied_squares())
return false;
// Separate piece type bitboards must have empty intersections
for (PieceType pt = PAWN; pt <= KING; pt++)
for (int i = 0; i < pieceCount[c][pt]; i++)
{
- if (piece_on(piece_list(c, pt, i)) != make_piece(c, pt))
+ if (piece_on(piece_list(c, pt)[i]) != make_piece(c, pt))
return false;
- if (index[piece_list(c, pt, i)] != i)
+ if (index[piece_list(c, pt)[i]] != i)
return false;
}
if (failedStep) (*failedStep)++;
if (debugCastleSquares)
- {
- for (Color c = WHITE; c <= BLACK; c++)
+ for (CastleRight f = WHITE_OO; f <= BLACK_OOO; f = CastleRight(f << 1))
{
- if (can_castle_kingside(c) && piece_on(initial_kr_square(c)) != make_piece(c, ROOK))
- return false;
+ if (!can_castle(f))
+ continue;
- if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != make_piece(c, ROOK))
+ Piece rook = (f & (WHITE_OO | WHITE_OOO) ? WR : BR);
+
+ if ( castleRightsMask[castleRookSquare[f]] != (ALL_CASTLES ^ f)
+ || piece_on(castleRookSquare[f]) != rook)
return false;
}
- if (castleRightsMask[initial_kr_square(WHITE)] != (ALL_CASTLES ^ WHITE_OO))
- return false;
- if (castleRightsMask[initial_qr_square(WHITE)] != (ALL_CASTLES ^ WHITE_OOO))
- return false;
- if (castleRightsMask[initial_kr_square(BLACK)] != (ALL_CASTLES ^ BLACK_OO))
- return false;
- if (castleRightsMask[initial_qr_square(BLACK)] != (ALL_CASTLES ^ BLACK_OOO))
- return false;
- }
if (failedStep) *failedStep = 0;
return true;
projects / stockfish / blobdiff