along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-////
-//// Includes
-////
-
-#include <algorithm>
#include <cassert>
#include <cstring>
#include <fstream>
#include "bitcount.h"
#include "movegen.h"
-#include "movepick.h"
#include "position.h"
#include "psqtab.h"
#include "rkiss.h"
-#include "san.h"
#include "tt.h"
#include "ucioption.h"
using std::cout;
using std::endl;
-
-////
-//// Position's static data definitions
-////
-
Key Position::zobrist[2][8][64];
Key Position::zobEp[64];
Key Position::zobCastle[16];
// Bonus for having the side to move (modified by Joona Kiiski)
const Score TempoValue = make_score(48, 22);
- bool isZero(char c) { return c == '0'; }
-
struct PieceLetters : public std::map<char, Piece> {
PieceLetters() {
nodes = 0;
}
-Position::Position(const string& fen, int th) {
+Position::Position(const string& fen, bool isChess960, int th) {
- from_fen(fen);
+ from_fen(fen, isChess960);
threadID = th;
}
/// 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) {
+void Position::from_fen(const string& fen, bool isChess960) {
/*
A FEN string defines a particular position using only the ASCII character set.
A FEN string contains six fields. The separator between fields is a space. The fields are:
1) Piece placement (from white's perspective). Each rank is described, starting with rank 8 and ending
- with rank 1; within each rank, the contents of each square are described from file a through file h.
+ with rank 1; within each rank, the contents of each square are described from file A through file H.
Following the Standard Algebraic Notation (SAN), each piece is identified by a single letter taken
from the standard English names. White pieces are designated using upper-case letters ("PNBRQK")
while Black take lowercase ("pnbrqk"). Blank squares are noted using digits 1 through 8 (the number
*/
char token;
+ int hmc, fmn;
std::istringstream ss(fen);
- Rank rank = RANK_8;
- File file = FILE_A;
+ Square sq = SQ_A8;
clear();
// 1. Piece placement field
while (ss.get(token) && token != ' ')
{
- if (isdigit(token))
+ if (pieceLetters.find(token) != pieceLetters.end())
{
- file += File(token - '0'); // Skip the given number of files
- continue;
+ put_piece(pieceLetters[token], sq);
+ sq++;
}
+ else if (isdigit(token))
+ sq += Square(token - '0'); // Skip the given number of files
else if (token == '/')
- {
- file = FILE_A;
- rank--;
- continue;
- }
-
- if (pieceLetters.find(token) == pieceLetters.end())
+ sq -= SQ_A3; // Jump back of 2 rows
+ else
goto incorrect_fen;
-
- put_piece(pieceLetters[token], make_square(file, rank));
- file++;
}
// 2. Active color
// 3. Castling availability
while (ss.get(token) && token != ' ')
- {
- if (token == '-')
- continue;
-
if (!set_castling_rights(token))
goto incorrect_fen;
- }
- // 4. En passant square -- ignore if no capture is possible
+ // 4. En passant square
char col, row;
if ( (ss.get(col) && (col >= 'a' && col <= 'h'))
&& (ss.get(row) && (row == '3' || row == '6')))
{
- Square fenEpSquare = make_square(file_from_char(col), rank_from_char(row));
- Color them = opposite_color(sideToMove);
+ st->epSquare = make_square(file_from_char(col), rank_from_char(row));
- if (attacks_from<PAWN>(fenEpSquare, them) & pieces(PAWN, sideToMove))
- st->epSquare = fenEpSquare;
+ // Ignore if no capture is possible
+ Color them = opposite_color(sideToMove);
+ if (!(attacks_from<PAWN>(st->epSquare, them) & pieces(PAWN, sideToMove)))
+ st->epSquare = SQ_NONE;
}
- // 5-6. Halfmove clock and fullmove number are not parsed
+ // 5. Halfmove clock
+ if (ss >> hmc)
+ st->rule50 = hmc;
+
+ // 6. Fullmove number
+ if (ss >> fmn)
+ startPosPlyCounter = (fmn - 1) * 2 + int(sideToMove == BLACK);
// Various initialisations
castleRightsMask[make_square(initialKFile, RANK_1)] ^= WHITE_OO | WHITE_OOO;
castleRightsMask[make_square(initialQRFile, RANK_1)] ^= WHITE_OOO;
castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO;
- isChess960 = initialKFile != FILE_E
- || initialQRFile != FILE_A
- || initialKRFile != FILE_H;
-
+ chess960 = isChess960;
find_checkers();
st->key = compute_key();
initialKRFile = rookFile;
}
}
- else return false;
+ else
+ return token == '-';
return true;
}
Square sq;
char emptyCnt = '0';
- for (Rank rank = RANK_8; rank >= RANK_1; rank--)
+ for (Rank rank = RANK_8; rank >= RANK_1; rank--, fen += '/')
{
for (File file = FILE_A; file <= FILE_H; file++)
{
if (square_is_occupied(sq))
{
- fen += emptyCnt;
+ if (emptyCnt != '0')
+ {
+ fen += emptyCnt;
+ emptyCnt = '0';
+ }
fen += pieceLetters.from_piece(piece_on(sq));
- emptyCnt = '0';
} else
emptyCnt++;
}
- fen += emptyCnt;
- fen += '/';
- emptyCnt = '0';
+
+ if (emptyCnt != '0')
+ {
+ fen += emptyCnt;
+ emptyCnt = '0';
+ }
}
- fen.erase(std::remove_if(fen.begin(), fen.end(), isZero), fen.end());
- fen.erase(--fen.end());
fen += (sideToMove == WHITE ? " w " : " b ");
if (st->castleRights != CASTLES_NONE)
{
if (can_castle_kingside(WHITE))
- fen += isChess960 ? char(toupper(file_to_char(initialKRFile))) : 'K';
+ fen += chess960 ? char(toupper(file_to_char(initialKRFile))) : 'K';
if (can_castle_queenside(WHITE))
- fen += isChess960 ? char(toupper(file_to_char(initialQRFile))) : 'Q';
+ fen += chess960 ? char(toupper(file_to_char(initialQRFile))) : 'Q';
if (can_castle_kingside(BLACK))
- fen += isChess960 ? file_to_char(initialKRFile) : 'k';
+ fen += chess960 ? file_to_char(initialKRFile) : 'k';
if (can_castle_queenside(BLACK))
- fen += isChess960 ? file_to_char(initialQRFile) : 'q';
+ fen += chess960 ? file_to_char(initialQRFile) : 'q';
} else
fen += '-';
void Position::print(Move move) const {
const char* dottedLine = "\n+---+---+---+---+---+---+---+---+\n";
- static bool requestPending = false;
-
- // Check for reentrancy, as example when called from inside
- // MovePicker that is used also here in move_to_san()
- if (requestPending)
- return;
-
- requestPending = true;
if (move)
{
for (File file = FILE_A; file <= FILE_H; file++)
{
Square sq = make_square(file, rank);
- char c = (color_of_piece_on(sq) == BLACK ? '=' : ' ');
Piece piece = piece_on(sq);
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 << '|';
}
}
cout << dottedLine << "Fen is: " << to_fen() << "\nKey is: " << st->key << endl;
- requestPending = false;
}
case WB: case BB: return attacks_from<BISHOP>(s);
case WR: case BR: return attacks_from<ROOK>(s);
case WQ: case BQ: return attacks_from<QUEEN>(s);
- default: return StepAttackBB[p][s];
+ default: return StepAttacksBB[p][s];
}
}
case WB: case BB: return bishop_attacks_bb(s, occ);
case WR: case BR: return rook_attacks_bb(s, occ);
case WQ: case BQ: return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ);
- default: return StepAttackBB[p][s];
+ default: return StepAttacksBB[p][s];
}
}
Bitboard b = occupied_squares();
assert(to == ep_square());
- assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
- assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
+ assert(piece_on(from) == make_piece(us, PAWN));
+ assert(piece_on(capsq) == make_piece(them, PAWN));
assert(piece_on(to) == PIECE_NONE);
clear_bit(&b, from);
Square from = move_from(m);
assert(color_of_piece_on(from) == us);
- assert(piece_on(king_square(us)) == piece_of_color_and_type(us, KING));
+ 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.
// 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 ( !pinned
- || !bit_is_set(pinned, from)
- || (direction_between_squares(from, king_square(us)) == direction_between_squares(move_to(m), king_square(us))));
+ return !pinned
+ || !bit_is_set(pinned, from)
+ || squares_aligned(from, move_to(m), king_square(us));
}
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.
+
+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));
+
+ 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.
+
+bool Position::move_is_legal(const Move m, Bitboard pinned) const {
+
+ assert(is_ok());
+ assert(pinned == pinned_pieces(sideToMove));
+
+ Color us = sideToMove;
+ Color them = opposite_color(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_legal(m);
+
+ // 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)
+ return false;
+
+ // The destination square cannot be occupied by a friendly piece
+ if (color_of_piece_on(to) == us)
+ return false;
+
+ // Handle the special case of a pawn move
+ if (type_of_piece(pc) == PAWN)
+ {
+ // Move direction must be compatible with pawn color
+ int direction = to - from;
+ if ((us == WHITE) != (direction > 0))
+ return false;
+
+ // 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)
+ return false;
+
+ // Proceed according to the square delta between the origin and
+ // destination squares.
+ switch (direction)
+ {
+ case DELTA_NW:
+ case DELTA_NE:
+ case DELTA_SW:
+ 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;
+
+ case DELTA_N:
+ case DELTA_S:
+ // Pawn push. The destination square must be empty.
+ if (!square_is_empty(to))
+ return false;
+ break;
+
+ case DELTA_NN:
+ // 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
+ || !square_is_empty(to)
+ || !square_is_empty(from + DELTA_N))
+ return false;
+ 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;
+
+ 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);
+}
+
/// Position::move_is_check() tests whether a pseudo-legal move is a check
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) == piece_of_color_and_type(opposite_color(side_to_move()), KING));
+ assert(piece_on(ci.ksq) == make_piece(opposite_color(side_to_move()), KING));
Square from = move_from(m);
Square to = move_to(m);
{
// For pawn and king moves we need to verify also direction
if ( (pt != PAWN && pt != KING)
- ||(direction_between_squares(from, ci.ksq) != direction_between_squares(to, ci.ksq)))
+ || !squares_aligned(from, to, ci.ksq))
return true;
}
}
+/// 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;
+
+ 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;
+
+ // 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.
+ 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.
assert(is_ok());
assert(move_is_ok(m));
+ assert(&newSt != st);
nodes++;
Key key = st->key;
Value npMaterial[2];
};
- if (&newSt != st)
- memcpy(&newSt, st, sizeof(ReducedStateInfo));
+ memcpy(&newSt, st, sizeof(ReducedStateInfo));
newSt.previous = st;
st = &newSt;
assert(color_of_piece_on(from) == us);
assert(color_of_piece_on(to) == them || square_is_empty(to));
- assert(!(ep || pm) || piece == piece_of_color_and_type(us, PAWN));
+ assert(!(ep || pm) || piece == make_piece(us, PAWN));
assert(!pm || relative_rank(us, to) == RANK_8);
if (capture)
// Update pawn hash key and prefetch in L1/L2 cache
st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
- prefetchPawn(st->pawnKey, threadID);
// Set en passant square, only if moved pawn can be captured
if ((to ^ from) == 16)
// Insert promoted piece instead of pawn
clear_bit(&(byTypeBB[PAWN]), to);
set_bit(&(byTypeBB[promotion]), to);
- board[to] = piece_of_color_and_type(us, promotion);
+ board[to] = make_piece(us, promotion);
// Update piece counts
pieceCount[us][promotion]++;
}
}
+ // Prefetch pawn and material hash tables
+ prefetchTables(st->pawnKey, st->materialKey, threadID);
+
// Update incremental scores
st->value += pst_delta(piece, from, to);
assert(to == st->epSquare);
assert(relative_rank(opposite_color(them), to) == RANK_6);
assert(piece_on(to) == PIECE_NONE);
- assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
+ assert(piece_on(capsq) == make_piece(them, PAWN));
board[capsq] = PIECE_NONE;
}
Square rfrom = move_to(m); // HACK: See comment at beginning of function
Square kto, rto;
- assert(piece_on(kfrom) == piece_of_color_and_type(us, KING));
- assert(piece_on(rfrom) == piece_of_color_and_type(us, ROOK));
+ assert(piece_on(kfrom) == make_piece(us, KING));
+ assert(piece_on(rfrom) == make_piece(us, ROOK));
// Find destination squares for king and rook
if (rfrom > kfrom) // O-O
set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
// Update board array
- Piece king = piece_of_color_and_type(us, KING);
- Piece rook = piece_of_color_and_type(us, ROOK);
+ Piece king = make_piece(us, KING);
+ Piece rook = make_piece(us, ROOK);
board[kfrom] = board[rfrom] = PIECE_NONE;
board[kto] = king;
board[rto] = rook;
assert(!pm || relative_rank(us, to) == RANK_8);
assert(!ep || to == st->previous->epSquare);
assert(!ep || relative_rank(us, to) == RANK_6);
- assert(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN));
+ assert(!ep || piece_on(to) == make_piece(us, PAWN));
if (pm) // promotion ?
{
pt = PAWN;
assert(promotion >= KNIGHT && promotion <= QUEEN);
- assert(piece_on(to) == piece_of_color_and_type(us, promotion));
+ assert(piece_on(to) == make_piece(us, promotion));
// Replace promoted piece with a pawn
clear_bit(&(byTypeBB[promotion]), to);
do_move_bb(&(byTypeBB[pt]), move_bb);
do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
- board[from] = piece_of_color_and_type(us, pt);
+ board[from] = make_piece(us, pt);
board[to] = PIECE_NONE;
// Update piece list
set_bit(&(byTypeBB[st->capturedType]), capsq);
set_bit(&(byTypeBB[0]), capsq);
- board[capsq] = piece_of_color_and_type(them, st->capturedType);
+ board[capsq] = make_piece(them, st->capturedType);
// Update piece count
pieceCount[them][st->capturedType]++;
rto = relative_square(us, SQ_D1);
}
- assert(piece_on(kto) == piece_of_color_and_type(us, KING));
- assert(piece_on(rto) == piece_of_color_and_type(us, ROOK));
+ 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);
// Update board
board[rto] = board[kto] = PIECE_NONE;
- board[rfrom] = piece_of_color_and_type(us, ROOK);
- board[kfrom] = piece_of_color_and_type(us, KING);
+ board[rfrom] = make_piece(us, ROOK);
+ board[kfrom] = make_piece(us, KING);
// Update piece lists
pieceList[us][KING][index[kto]] = kfrom;
}
-/// Position::reset_game_ply() simply sets gamePly to 0. It is used from the
-/// UCI interface code, whenever a non-reversible move is made in a
-/// 'position fen <fen> moves m1 m2 ...' command. This makes it possible
-/// for the program to handle games of arbitrary length, as long as the GUI
-/// handles draws by the 50 move rule correctly.
-
-void Position::reset_game_ply() {
-
- st->gamePly = 0;
-}
-
-void Position::inc_startpos_ply_counter() {
-
- startPosPlyCounter++;
-}
-
/// Position::put_piece() puts a piece on the given square of the board,
/// updating the board array, pieces list, bitboards, and piece counts.
return true;
// Draw by the 50 moves rule?
- if (st->rule50 > 99 && (st->rule50 > 100 || !is_mate()))
+ if (st->rule50 > 99 && !is_mate())
return true;
// Draw by repetition?
bool Position::is_mate() const {
- MoveStack moves[MOVES_MAX];
- return is_check() && generate_moves(*this, moves) == moves;
-}
-
-
-/// Position::has_mate_threat() tests whether the side to move is under
-/// a threat of being mated in one from the current position.
-
-bool Position::has_mate_threat() {
-
- MoveStack mlist[MOVES_MAX], *last, *cur;
- StateInfo st1, st2;
- bool mateFound = false;
-
- // If we are under check it's up to evasions to do the job
- if (is_check())
- return false;
-
- // First pass the move to our opponent doing a null move
- do_null_move(st1);
-
- // Then generate pseudo-legal moves that could give check
- last = generate_non_capture_checks(*this, mlist);
- last = generate_captures(*this, last);
-
- // Loop through the moves, and see if one of them gives mate
- Bitboard pinned = pinned_pieces(sideToMove);
- CheckInfo ci(*this);
- for (cur = mlist; cur != last && !mateFound; cur++)
- {
- Move move = cur->move;
- if ( !pl_move_is_legal(move, pinned)
- || !move_is_check(move, ci))
- continue;
-
- do_move(move, st2, ci, true);
-
- if (is_mate())
- mateFound = true;
-
- undo_move(move);
- }
-
- undo_null_move();
- return mateFound;
+ MoveStack moves[MAX_MOVES];
+ return is_check() && generate<MV_LEGAL>(*this, moves) == moves;
}
if (failedStep) (*failedStep)++;
if (debugPieceList)
- {
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
for (int i = 0; i < pieceCount[c][pt]; i++)
{
- if (piece_on(piece_list(c, pt, i)) != piece_of_color_and_type(c, pt))
+ if (piece_on(piece_list(c, pt, i)) != make_piece(c, pt))
return false;
if (index[piece_list(c, pt, i)] != i)
return false;
}
- }
if (failedStep) (*failedStep)++;
- if (debugCastleSquares) {
- for (Color c = WHITE; c <= BLACK; c++) {
- if (can_castle_kingside(c) && piece_on(initial_kr_square(c)) != piece_of_color_and_type(c, ROOK))
+ if (debugCastleSquares)
+ {
+ for (Color c = WHITE; c <= BLACK; c++)
+ {
+ if (can_castle_kingside(c) && piece_on(initial_kr_square(c)) != make_piece(c, ROOK))
return false;
- if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != piece_of_color_and_type(c, ROOK))
+
+ if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != make_piece(c, ROOK))
return false;
}
if (castleRightsMask[initial_kr_square(WHITE)] != (ALL_CASTLES ^ WHITE_OO))
projects / stockfish / blobdiff