#include <fstream>
#include <iostream>
+#include "bitcount.h"
#include "mersenne.h"
#include "movegen.h"
#include "movepick.h"
#include "position.h"
#include "psqtab.h"
#include "san.h"
+#include "tt.h"
#include "ucioption.h"
+using std::string;
+
////
//// Variables
////
-extern SearchStack EmptySearchStack;
-
int Position::castleRightsMask[64];
Key Position::zobrist[2][8][64];
Key Position::zobCastle[16];
Key Position::zobMaterial[2][8][16];
Key Position::zobSideToMove;
+Key Position::zobExclusion;
-Value Position::MgPieceSquareTable[16][64];
-Value Position::EgPieceSquareTable[16][64];
+Score Position::PieceSquareTable[16][64];
static bool RequestPending = false;
-////
-//// Functions
-////
/// Constructors
+CheckInfo::CheckInfo(const Position& pos) {
+
+ Color us = pos.side_to_move();
+ Color them = opposite_color(us);
+
+ ksq = pos.king_square(them);
+ dcCandidates = pos.discovered_check_candidates(us);
+
+ 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;
+}
+
+
+/// Position c'tors. Here we always create a slower but safer copy of
+/// the original position or the FEN string, we want the new born Position
+/// object do not depend on any external data. Instead if we know what we
+/// are doing and we need speed we can create a position with default
+/// c'tor Position() and then use just fast_copy().
+
+Position::Position() {}
+
Position::Position(const Position& pos) {
- copy(pos);
+
+ fast_copy(pos);
+ detach(); // Always detach() in copy c'tor to avoid surprises
}
-Position::Position(const std::string& fen) {
+Position::Position(const string& fen) {
+
from_fen(fen);
}
+/// Position::fast_copy() creates a partial copy of the given position,
+/// only data that changes with a do_move() / undo_move() cycle is copied,
+/// in particular for stateInfo are copied only the pointers, so that the
+/// actual data remains stored in the parent Position. This is not a problem
+/// if the parent Position is known not to be destroyed while we are still alive,
+/// as is the common case, see detach() otherwise.
+
+void Position::fast_copy(const Position& pos) {
+
+ memcpy(this, &pos, sizeof(Position));
+}
+
+
+/// 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 std::string& fen) {
+void Position::from_fen(const string& fen) {
- static const std::string pieceLetters = "KQRBNPkqrbnp";
+ static const string pieceLetters = "KQRBNPkqrbnp";
static const Piece pieces[] = { WK, WQ, WR, WB, WN, WP, BK, BQ, BR, BB, BN, BP };
clear();
continue;
}
size_t idx = pieceLetters.find(fen[i]);
- if (idx == std::string::npos)
+ if (idx == string::npos)
{
std::cout << "Error in FEN at character " << i << std::endl;
return;
}
i++;
- while(strchr("KQkqabcdefghABCDEFGH-", fen[i])) {
- if (fen[i] == '-')
- {
- i++;
- break;
- }
- else if(fen[i] == 'K') allow_oo(WHITE);
- else if(fen[i] == 'Q') allow_ooo(WHITE);
- else if(fen[i] == 'k') allow_oo(BLACK);
- else if(fen[i] == 'q') allow_ooo(BLACK);
- else if(fen[i] >= 'A' && fen[i] <= 'H') {
- File rookFile, kingFile = FILE_NONE;
- for(Square square = SQ_B1; square <= SQ_G1; square++)
- if(piece_on(square) == WK)
- kingFile = square_file(square);
- if(kingFile == FILE_NONE) {
- std::cout << "Error in FEN at character " << i << std::endl;
- return;
- }
- initialKFile = kingFile;
- rookFile = File(fen[i] - 'A') + FILE_A;
- if(rookFile < initialKFile) {
- allow_ooo(WHITE);
- initialQRFile = rookFile;
- }
- else {
- allow_oo(WHITE);
- initialKRFile = rookFile;
+ while (strchr("KQkqabcdefghABCDEFGH-", fen[i])) {
+ if (fen[i] == '-')
+ {
+ i++;
+ break;
}
- }
- else if(fen[i] >= 'a' && fen[i] <= 'h') {
- File rookFile, kingFile = FILE_NONE;
- for(Square square = SQ_B8; square <= SQ_G8; square++)
- if(piece_on(square) == BK)
- kingFile = square_file(square);
- if(kingFile == FILE_NONE) {
- std::cout << "Error in FEN at character " << i << std::endl;
- return;
+ else if (fen[i] == 'K') allow_oo(WHITE);
+ else if (fen[i] == 'Q') allow_ooo(WHITE);
+ else if (fen[i] == 'k') allow_oo(BLACK);
+ else if (fen[i] == 'q') allow_ooo(BLACK);
+ else if (fen[i] >= 'A' && fen[i] <= 'H') {
+ File rookFile, kingFile = FILE_NONE;
+ for (Square square = SQ_B1; square <= SQ_G1; square++)
+ if (piece_on(square) == WK)
+ kingFile = square_file(square);
+ if (kingFile == FILE_NONE) {
+ std::cout << "Error in FEN at character " << i << std::endl;
+ return;
+ }
+ initialKFile = kingFile;
+ rookFile = File(fen[i] - 'A') + FILE_A;
+ if (rookFile < initialKFile) {
+ allow_ooo(WHITE);
+ initialQRFile = rookFile;
+ }
+ else {
+ allow_oo(WHITE);
+ initialKRFile = rookFile;
+ }
}
- initialKFile = kingFile;
- rookFile = File(fen[i] - 'a') + FILE_A;
- if(rookFile < initialKFile) {
- allow_ooo(BLACK);
- initialQRFile = rookFile;
+ else if (fen[i] >= 'a' && fen[i] <= 'h') {
+ File rookFile, kingFile = FILE_NONE;
+ for (Square square = SQ_B8; square <= SQ_G8; square++)
+ if (piece_on(square) == BK)
+ kingFile = square_file(square);
+ if (kingFile == FILE_NONE) {
+ std::cout << "Error in FEN at character " << i << std::endl;
+ return;
+ }
+ initialKFile = kingFile;
+ rookFile = File(fen[i] - 'a') + FILE_A;
+ if (rookFile < initialKFile) {
+ allow_ooo(BLACK);
+ initialQRFile = rookFile;
+ }
+ else {
+ allow_oo(BLACK);
+ initialKRFile = rookFile;
+ }
}
else {
- allow_oo(BLACK);
- initialKRFile = rookFile;
+ std::cout << "Error in FEN at character " << i << std::endl;
+ return;
}
- }
- else {
- std::cout << "Error in FEN at character " << i << std::endl;
- return;
- }
- i++;
+ i++;
}
// Skip blanks
while (fen[i] == ' ')
i++;
- // En passant square
+ // En passant square -- ignore if no capture is possible
if ( i <= fen.length() - 2
&& (fen[i] >= 'a' && fen[i] <= 'h')
&& (fen[i+1] == '3' || fen[i+1] == '6'))
- st->epSquare = square_from_string(fen.substr(i, 2));
+ {
+ Square fenEpSquare = square_from_string(fen.substr(i, 2));
+ Color them = opposite_color(sideToMove);
+ if (attacks_from<PAWN>(fenEpSquare, them) & this->pieces(PAWN, sideToMove))
+ st->epSquare = square_from_string(fen.substr(i, 2));
+ }
// Various initialisation
for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
st->key = compute_key();
st->pawnKey = compute_pawn_key();
st->materialKey = compute_material_key();
- st->mgValue = compute_value<MidGame>();
- st->egValue = compute_value<EndGame>();
- npMaterial[WHITE] = compute_non_pawn_material(WHITE);
- npMaterial[BLACK] = compute_non_pawn_material(BLACK);
+ st->value = compute_value();
+ st->npMaterial[WHITE] = compute_non_pawn_material(WHITE);
+ st->npMaterial[BLACK] = compute_non_pawn_material(BLACK);
}
/// Position::to_fen() converts the position object to a FEN string. This is
/// probably only useful for debugging.
-const std::string Position::to_fen() const {
+const string Position::to_fen() const {
- static const std::string pieceLetters = " PNBRQK pnbrqk";
- std::string fen;
+ static const string pieceLetters = " PNBRQK pnbrqk";
+ string fen;
int skip;
for (Rank rank = RANK_8; rank >= RANK_1; rank--)
fen += (sideToMove == WHITE ? "w " : "b ");
if (st->castleRights != NO_CASTLES)
{
- if (can_castle_kingside(WHITE)) fen += 'K';
- if (can_castle_queenside(WHITE)) fen += 'Q';
- if (can_castle_kingside(BLACK)) fen += 'k';
- if (can_castle_queenside(BLACK)) fen += 'q';
+ if (initialKFile == FILE_E && initialQRFile == FILE_A && initialKRFile == FILE_H)
+ {
+ if (can_castle_kingside(WHITE)) fen += 'K';
+ if (can_castle_queenside(WHITE)) fen += 'Q';
+ if (can_castle_kingside(BLACK)) fen += 'k';
+ if (can_castle_queenside(BLACK)) fen += 'q';
+ }
+ else
+ {
+ if (can_castle_kingside(WHITE))
+ fen += char(toupper(file_to_char(initialKRFile)));
+ if (can_castle_queenside(WHITE))
+ fen += char(toupper(file_to_char(initialQRFile)));
+ if (can_castle_kingside(BLACK))
+ fen += file_to_char(initialKRFile);
+ if (can_castle_queenside(BLACK))
+ fen += file_to_char(initialQRFile);
+ }
} else
fen += '-';
void Position::print(Move m) const {
- static const std::string pieceLetters = " PNBRQK PNBRQK .";
+ static const string pieceLetters = " PNBRQK PNBRQK .";
// Check for reentrancy, as example when called from inside
// MovePicker that is used also here in move_to_san()
std::cout << std::endl;
if (m != MOVE_NONE)
{
- std::string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : "");
- std::cout << "Move is: " << col << move_to_san(*this, m) << std::endl;
+ Position p(*this);
+ string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : "");
+ std::cout << "Move is: " << col << move_to_san(p, m) << std::endl;
}
for (Rank rank = RANK_8; rank >= RANK_1; rank--)
{
}
-/// Position::copy() creates a copy of the input position.
-
-void Position::copy(const Position &pos) {
-
- memcpy(this, &pos, sizeof(Position));
-}
-
-
/// 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.
-/// Note that checkersBB bitboard must be already updated.
+/// Bitboard checkersBB must be already updated when looking for pinners.
template<bool FindPinned>
Bitboard Position::hidden_checkers(Color c) const {
- Bitboard pinners, result = EmptyBoardBB;
+ Bitboard result = EmptyBoardBB;
+ Bitboard pinners = pieces_of_color(FindPinned ? opposite_color(c) : c);
// 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 = (rooks_and_queens(FindPinned ? opposite_color(c) : c) & RookPseudoAttacks[ksq])
- | (bishops_and_queens(FindPinned ? opposite_color(c) : c) & BishopPseudoAttacks[ksq]);
+ // 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;
/// Position:pinned_pieces() returns a bitboard of all pinned (against the
-/// king) pieces for the given color.
+/// king) pieces for the given color. Note that checkersBB bitboard must
+/// be already updated.
Bitboard Position::pinned_pieces(Color c) const {
/// Position:discovered_check_candidates() returns a bitboard containing all
/// pieces for the given side which are candidates for giving a discovered
-/// check.
+/// check. Contrary to pinned_pieces() here there is no need of checkersBB
+/// to be already updated.
Bitboard Position::discovered_check_candidates(Color c) const {
return hidden_checkers<false>(c);
}
-/// Position::attacks_to() computes a bitboard containing all pieces which
-/// attacks a given square. There are two versions of this function: One
-/// which finds attackers of both colors, and one which only finds the
-/// attackers for one side.
+/// Position::attackers_to() computes a bitboard containing all pieces which
+/// attacks a given square.
-Bitboard Position::attacks_to(Square s) const {
+Bitboard Position::attackers_to(Square s) const {
- return (pawn_attacks(BLACK, s) & pawns(WHITE))
- | (pawn_attacks(WHITE, s) & pawns(BLACK))
- | (piece_attacks<KNIGHT>(s) & pieces_of_type(KNIGHT))
- | (piece_attacks<ROOK>(s) & rooks_and_queens())
- | (piece_attacks<BISHOP>(s) & bishops_and_queens())
- | (piece_attacks<KING>(s) & pieces_of_type(KING));
+ return (attacks_from<PAWN>(s, BLACK) & pieces(PAWN, WHITE))
+ | (attacks_from<PAWN>(s, WHITE) & pieces(PAWN, BLACK))
+ | (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
+ | (attacks_from<ROOK>(s) & pieces(ROOK, QUEEN))
+ | (attacks_from<BISHOP>(s) & pieces(BISHOP, QUEEN))
+ | (attacks_from<KING>(s) & pieces(KING));
}
-/// Position::piece_attacks_square() tests whether the piece on square f
-/// attacks square t.
+/// Position::attacks_from() computes a bitboard of all attacks
+/// of a given piece put in a given square.
-bool Position::piece_attacks_square(Piece p, Square f, Square t) const {
+Bitboard Position::attacks_from(Piece p, Square s) const {
- assert(square_is_ok(f));
- assert(square_is_ok(t));
+ assert(square_is_ok(s));
switch (p)
{
- case WP: return pawn_attacks_square(WHITE, f, t);
- case BP: return pawn_attacks_square(BLACK, f, t);
- case WN: case BN: return piece_attacks_square<KNIGHT>(f, t);
- case WB: case BB: return piece_attacks_square<BISHOP>(f, t);
- case WR: case BR: return piece_attacks_square<ROOK>(f, t);
- case WQ: case BQ: return piece_attacks_square<QUEEN>(f, t);
- case WK: case BK: return piece_attacks_square<KING>(f, t);
+ case WP: return attacks_from<PAWN>(s, WHITE);
+ case BP: return attacks_from<PAWN>(s, BLACK);
+ case WN: case BN: return attacks_from<KNIGHT>(s);
+ 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);
+ case WK: case BK: return attacks_from<KING>(s);
default: break;
}
return false;
assert(square_is_occupied(f));
- if (piece_attacks_square(piece_on(f), t, s))
+ if (bit_is_set(attacks_from(piece_on(f), t), s))
return true;
// Move the piece and scan for X-ray attacks behind it
Color us = color_of_piece_on(f);
clear_bit(&occ, f);
set_bit(&occ, t);
- Bitboard xray = ( (rook_attacks_bb(s, occ) & rooks_and_queens())
- |(bishop_attacks_bb(s, occ) & bishops_and_queens())) & pieces_of_color(us);
+ Bitboard xray = ( (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN))
+ |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN))) & pieces_of_color(us);
// If we have attacks we need to verify that are caused by our move
// and are not already existent ones.
- return xray && (xray ^ (xray & piece_attacks<QUEEN>(s)));
+ return xray && (xray ^ (xray & attacks_from<QUEEN>(s)));
}
/// 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::attacks_to, which is probably
+/// 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 = attacks_to(king_square(us), opposite_color(us));
+ 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) const {
-
- // If we're in check, all pseudo-legal moves are legal, because our
- // check evasion generator only generates true legal moves.
- return is_check() || pl_move_is_legal(m, pinned_pieces(side_to_move()));
-}
-
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_check());
// Castling moves are checked for legality during move generation.
if (move_is_castle(m))
Color us = side_to_move();
Square from = move_from(m);
- Square ksq = king_square(us);
assert(color_of_piece_on(from) == us);
- assert(piece_on(ksq) == piece_of_color_and_type(us, KING));
+ assert(piece_on(king_square(us)) == piece_of_color_and_type(us, KING));
- // En passant captures are a tricky special case. Because they are
+ // 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))
Square to = move_to(m);
Square capsq = make_square(square_file(to), square_rank(from));
Bitboard b = occupied_squares();
+ Square ksq = king_square(us);
assert(to == ep_square());
assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
clear_bit(&b, capsq);
set_bit(&b, to);
- return !(rook_attacks_bb(ksq, b) & rooks_and_queens(them))
- && !(bishop_attacks_bb(ksq, b) & bishops_and_queens(them));
+ return !(rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, them))
+ && !(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them));
}
// If the moving piece is a king, check whether the destination
// square is attacked by the opponent.
- if (from == ksq)
- return !(square_is_attacked(move_to(m), opposite_color(us)));
+ if (type_of_piece_on(from) == KING)
+ return !(attackers_to(move_to(m)) & pieces_of_color(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.
return ( !pinned
|| !bit_is_set(pinned, from)
- || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq)));
+ || (direction_between_squares(from, king_square(us)) == direction_between_squares(move_to(m), king_square(us))));
+}
+
+
+/// 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);
}
bool Position::move_is_check(Move m) const {
- Bitboard dc = discovered_check_candidates(side_to_move());
- return move_is_check(m, dc);
+ return move_is_check(m, CheckInfo(*this));
}
-bool Position::move_is_check(Move m, Bitboard dcCandidates) const {
+bool Position::move_is_check(Move m, const CheckInfo& ci) const {
assert(is_ok());
assert(move_is_ok(m));
- assert(dcCandidates == discovered_check_candidates(side_to_move()));
+ 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));
- Color us = side_to_move();
- Color them = opposite_color(us);
Square from = move_from(m);
Square to = move_to(m);
- Square ksq = king_square(them);
+ PieceType pt = type_of_piece_on(from);
- assert(color_of_piece_on(from) == us);
- assert(piece_on(ksq) == piece_of_color_and_type(them, KING));
+ // Direct check ?
+ if (bit_is_set(ci.checkSq[pt], to))
+ return true;
- // Proceed according to the type of the moving piece
- switch (type_of_piece_on(from))
+ // Discovery check ?
+ if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
{
- case PAWN:
-
- if (bit_is_set(pawn_attacks(them, ksq), to)) // Normal check?
- return true;
-
- if ( dcCandidates // Discovered check?
- && bit_is_set(dcCandidates, from)
- && (direction_between_squares(from, ksq) != direction_between_squares(to, ksq)))
+ // 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)))
return true;
+ }
- if (move_promotion(m)) // Promotion with check?
- {
- Bitboard b = occupied_squares();
- clear_bit(&b, from);
-
- switch (move_promotion(m))
- {
- case KNIGHT:
- return bit_is_set(piece_attacks<KNIGHT>(to), ksq);
- case BISHOP:
- return bit_is_set(bishop_attacks_bb(to, b), ksq);
- case ROOK:
- return bit_is_set(rook_attacks_bb(to, b), ksq);
- case QUEEN:
- return bit_is_set(queen_attacks_bb(to, b), ksq);
- default:
- assert(false);
- }
- }
- // En passant capture with check? We have already handled the case
- // 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.
- else if (move_is_ep(m))
- {
- Square capsq = make_square(square_file(to), square_rank(from));
- Bitboard b = occupied_squares();
- clear_bit(&b, from);
- clear_bit(&b, capsq);
- set_bit(&b, to);
- return (rook_attacks_bb(ksq, b) & rooks_and_queens(us))
- ||(bishop_attacks_bb(ksq, b) & bishops_and_queens(us));
- }
+ // Can we skip the ugly special cases ?
+ if (!move_is_special(m))
return false;
- // Test discovered check and normal check according to piece type
- case KNIGHT:
- return (dcCandidates && bit_is_set(dcCandidates, from))
- || bit_is_set(piece_attacks<KNIGHT>(ksq), to);
-
- case BISHOP:
- return (dcCandidates && bit_is_set(dcCandidates, from))
- || (direction_is_diagonal(ksq, to) && bit_is_set(piece_attacks<BISHOP>(ksq), to));
-
- case ROOK:
- return (dcCandidates && bit_is_set(dcCandidates, from))
- || (direction_is_straight(ksq, to) && bit_is_set(piece_attacks<ROOK>(ksq), to));
-
- case QUEEN:
- // Discovered checks are impossible!
- assert(!bit_is_set(dcCandidates, from));
- return ( (direction_is_straight(ksq, to) && bit_is_set(piece_attacks<ROOK>(ksq), to))
- || (direction_is_diagonal(ksq, to) && bit_is_set(piece_attacks<BISHOP>(ksq), to)));
-
- case KING:
- // Discovered check?
- if ( bit_is_set(dcCandidates, from)
- && (direction_between_squares(from, ksq) != direction_between_squares(to, ksq)))
- return true;
+ Color us = side_to_move();
+ Bitboard b = occupied_squares();
- // Castling with check?
- if (move_is_castle(m))
- {
- Square kfrom, kto, rfrom, rto;
- Bitboard b = occupied_squares();
- kfrom = from;
- rfrom = to;
+ // Promotion with check ?
+ if (move_is_promotion(m))
+ {
+ clear_bit(&b, from);
- if (rfrom > kfrom)
- {
- kto = relative_square(us, SQ_G1);
- rto = relative_square(us, SQ_F1);
- } else {
- kto = relative_square(us, SQ_C1);
- rto = relative_square(us, SQ_D1);
- }
- clear_bit(&b, kfrom);
- clear_bit(&b, rfrom);
- set_bit(&b, rto);
- set_bit(&b, kto);
- return bit_is_set(rook_attacks_bb(rto, b), ksq);
+ switch (move_promotion_piece(m))
+ {
+ case KNIGHT:
+ return bit_is_set(attacks_from<KNIGHT>(to), ci.ksq);
+ case BISHOP:
+ return bit_is_set(bishop_attacks_bb(to, b), ci.ksq);
+ case ROOK:
+ return bit_is_set(rook_attacks_bb(to, b), ci.ksq);
+ case QUEEN:
+ return bit_is_set(queen_attacks_bb(to, b), ci.ksq);
+ default:
+ assert(false);
}
- return false;
-
- default: // NO_PIECE_TYPE
- break;
}
- assert(false);
- return false;
-}
-
-/// Position::update_checkers() udpates chekers info given the move. It is called
-/// in do_move() and is faster then find_checkers().
-
-template<PieceType Piece>
-inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square from,
- Square to, Bitboard dcCandidates) {
-
- const bool Bishop = (Piece == QUEEN || Piece == BISHOP);
- const bool Rook = (Piece == QUEEN || Piece == ROOK);
- const bool Slider = Bishop || Rook;
-
- if ( ( (Bishop && bit_is_set(BishopPseudoAttacks[ksq], to))
- || (Rook && bit_is_set(RookPseudoAttacks[ksq], to)))
- && bit_is_set(piece_attacks<Piece>(ksq), to)) // slow, try to early skip
- set_bit(pCheckersBB, to);
-
- else if ( Piece != KING
- && !Slider
- && bit_is_set(piece_attacks<Piece>(ksq), to))
- set_bit(pCheckersBB, to);
+ // En passant capture with check? We have already handled the case
+ // 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))
+ {
+ Square capsq = make_square(square_file(to), square_rank(from));
+ 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));
+ }
- if (Piece != QUEEN && bit_is_set(dcCandidates, from))
+ // Castling with check ?
+ if (move_is_castle(m))
{
- if (Piece != ROOK)
- (*pCheckersBB) |= (piece_attacks<ROOK>(ksq) & rooks_and_queens(side_to_move()));
+ Square kfrom, kto, rfrom, rto;
+ kfrom = from;
+ rfrom = to;
- if (Piece != BISHOP)
- (*pCheckersBB) |= (piece_attacks<BISHOP>(ksq) & bishops_and_queens(side_to_move()));
+ if (rfrom > kfrom)
+ {
+ kto = relative_square(us, SQ_G1);
+ rto = relative_square(us, SQ_F1);
+ } else {
+ kto = relative_square(us, SQ_C1);
+ rto = relative_square(us, SQ_D1);
+ }
+ clear_bit(&b, kfrom);
+ clear_bit(&b, rfrom);
+ set_bit(&b, rto);
+ set_bit(&b, kto);
+ return bit_is_set(rook_attacks_bb(rto, b), ci.ksq);
}
+
+ return false;
}
void Position::do_move(Move m, StateInfo& newSt) {
- do_move(m, newSt, discovered_check_candidates(side_to_move()));
+ CheckInfo ci(*this);
+ do_move(m, newSt, ci, move_is_check(m, ci));
}
-void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) {
+void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) {
assert(is_ok());
assert(move_is_ok(m));
+ Bitboard key = st->key;
+
// Copy some fields of old state to our new StateInfo object except the
// ones which are recalculated from scratch anyway, then switch our state
// pointer to point to the new, ready to be updated, state.
struct ReducedStateInfo {
- Key key, pawnKey, materialKey;
- int castleRights, rule50;
+ Key pawnKey, materialKey;
+ int castleRights, rule50, pliesFromNull;
Square epSquare;
- Value mgValue, egValue;
+ Score value;
+ Value npMaterial[2];
};
memcpy(&newSt, st, sizeof(ReducedStateInfo));
- newSt.capture = NO_PIECE_TYPE;
newSt.previous = st;
st = &newSt;
// Save the current key to the history[] array, in order to be able to
// detect repetition draws.
- history[gamePly] = st->key;
+ history[gamePly] = key;
+ gamePly++;
+
+ // Update side to move
+ key ^= zobSideToMove;
// Increment the 50 moves rule draw counter. Resetting it to zero in the
// case of non-reversible moves is taken care of later.
st->rule50++;
+ st->pliesFromNull++;
if (move_is_castle(m))
+ {
+ st->key = key;
do_castle_move(m);
- else if (move_promotion(m))
- do_promotion_move(m);
- else if (move_is_ep(m))
- do_ep_move(m);
- else
+ return;
+ }
+
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square to = move_to(m);
+ bool ep = move_is_ep(m);
+ 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);
+
+ 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(!pm || relative_rank(us, to) == RANK_8);
+
+ if (capture)
+ do_capture_move(key, capture, them, to, ep);
+
+ // Update hash key
+ key ^= zobrist[us][pt][from] ^ zobrist[us][pt][to];
+
+ // Reset en passant square
+ if (st->epSquare != SQ_NONE)
{
- Color us = side_to_move();
- Color them = opposite_color(us);
- Square from = move_from(m);
- Square to = move_to(m);
+ key ^= zobEp[st->epSquare];
+ st->epSquare = SQ_NONE;
+ }
- assert(color_of_piece_on(from) == us);
- assert(color_of_piece_on(to) == them || piece_on(to) == EMPTY);
+ // Update castle rights, try to shortcut a common case
+ int cm = castleRightsMask[from] & castleRightsMask[to];
+ if (cm != ALL_CASTLES && ((cm & st->castleRights) != st->castleRights))
+ {
+ key ^= zobCastle[st->castleRights];
+ st->castleRights &= castleRightsMask[from];
+ st->castleRights &= castleRightsMask[to];
+ key ^= zobCastle[st->castleRights];
+ }
- PieceType piece = type_of_piece_on(from);
+ // Prefetch TT access as soon as we know key is updated
+ TT.prefetch(key);
- st->capture = type_of_piece_on(to);
+ // 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
- if (st->capture)
- do_capture_move(st->capture, them, to);
+ board[to] = board[from];
+ board[from] = EMPTY;
- // Move the piece
- clear_bit(&(byColorBB[us]), from);
- clear_bit(&(byTypeBB[piece]), from);
- clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- set_bit(&(byColorBB[us]), to);
- set_bit(&(byTypeBB[piece]), to);
- set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
- board[to] = board[from];
- board[from] = EMPTY;
+ // Update piece lists, note that index[from] is not updated and
+ // becomes stale. This works as long as index[] is accessed just
+ // by known occupied squares.
+ index[to] = index[from];
+ pieceList[us][pt][index[to]] = to;
- // Update hash key
- st->key ^= zobrist[us][piece][from] ^ zobrist[us][piece][to];
+ // If the moving piece was a pawn do some special extra work
+ if (pt == PAWN)
+ {
+ // Reset rule 50 draw counter
+ st->rule50 = 0;
- // Update incremental scores
- st->mgValue -= pst<MidGame>(us, piece, from);
- st->mgValue += pst<MidGame>(us, piece, to);
- st->egValue -= pst<EndGame>(us, piece, from);
- st->egValue += pst<EndGame>(us, piece, to);
+ // Update pawn hash key
+ st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
+
+ // 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))
+ {
+ st->epSquare = Square((int(from) + int(to)) / 2);
+ key ^= zobEp[st->epSquare];
+ }
+ }
+ }
- // If the moving piece was a king, update the king square
- if (piece == KING)
- kingSquare[us] = to;
+ // Update incremental scores
+ st->value += pst_delta(piece, from, to);
- // Reset en passant square
- if (st->epSquare != SQ_NONE)
- {
- st->key ^= zobEp[st->epSquare];
- st->epSquare = SQ_NONE;
- }
+ // Set capture piece
+ st->capture = capture;
- // If the moving piece was a pawn do some special extra work
- if (piece == PAWN)
- {
- // Reset rule 50 draw counter
- st->rule50 = 0;
-
- // Update pawn hash key
- st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
-
- // Set en passant square, only if moved pawn can be captured
- if (abs(int(to) - int(from)) == 16)
- {
- if ( (us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK)))
- || (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE))))
- {
- st->epSquare = Square((int(from) + int(to)) / 2);
- st->key ^= zobEp[st->epSquare];
- }
- }
- }
+ if (pm) // promotion ?
+ {
+ PieceType promotion = move_promotion_piece(m);
+
+ assert(promotion >= KNIGHT && promotion <= QUEEN);
+
+ // 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);
+
+ // Update material key
+ st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]];
+ st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1];
+
+ // Update piece counts
+ pieceCount[us][PAWN]--;
+ pieceCount[us][promotion]++;
+
+ // Update piece lists, move the last pawn at index[to] position
+ // and shrink the list. Add a new promotion piece to the list.
+ Square lastPawnSquare = pieceList[us][PAWN][pieceCount[us][PAWN]];
+ index[lastPawnSquare] = index[to];
+ pieceList[us][PAWN][index[lastPawnSquare]] = lastPawnSquare;
+ pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE;
+ index[to] = pieceCount[us][promotion] - 1;
+ pieceList[us][promotion][index[to]] = to;
+
+ // Partially revert hash keys update
+ key ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to];
+ st->pawnKey ^= zobrist[us][PAWN][to];
+
+ // Partially revert and update incremental scores
+ st->value -= pst(us, PAWN, to);
+ st->value += pst(us, promotion, to);
+
+ // Update material
+ st->npMaterial[us] += piece_value_midgame(promotion);
+ }
- // Update piece lists
- pieceList[us][piece][index[from]] = to;
- index[to] = index[from];
+ // Update the key with the final value
+ st->key = key;
- // Update castle rights
- st->key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[from];
- st->castleRights &= castleRightsMask[to];
- st->key ^= zobCastle[st->castleRights];
+ // Update checkers bitboard, piece must be already moved
+ st->checkersBB = EmptyBoardBB;
- // Update checkers bitboard, piece must be already moved
- st->checkersBB = EmptyBoardBB;
- Square ksq = king_square(them);
- switch (piece)
- {
- case PAWN: update_checkers<PAWN>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case KNIGHT: update_checkers<KNIGHT>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case BISHOP: update_checkers<BISHOP>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case ROOK: update_checkers<ROOK>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case QUEEN: update_checkers<QUEEN>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- case KING: update_checkers<KING>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
- default: assert(false); break;
- }
+ if (moveIsCheck)
+ {
+ if (ep | pm)
+ st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us);
+ else
+ {
+ // Direct checks
+ if (bit_is_set(ci.checkSq[pt], to))
+ st->checkersBB = SetMaskBB[to];
+
+ // Discovery checks
+ if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
+ {
+ if (pt != ROOK)
+ st->checkersBB |= (attacks_from<ROOK>(ci.ksq) & pieces(ROOK, QUEEN, us));
+
+ if (pt != BISHOP)
+ st->checkersBB |= (attacks_from<BISHOP>(ci.ksq) & pieces(BISHOP, QUEEN, us));
+ }
+ }
}
// Finish
- st->key ^= zobSideToMove;
sideToMove = opposite_color(sideToMove);
- gamePly++;
-
- st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
- st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
+ st->value += (sideToMove == WHITE ? TempoValue : -TempoValue);
assert(is_ok());
}
/// Position::do_capture_move() is a private method used to update captured
/// piece info. It is called from the main Position::do_move function.
-void Position::do_capture_move(PieceType capture, Color them, Square to) {
+void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Square to, bool ep) {
assert(capture != KING);
+ Square capsq = to;
+
+ if (ep) // en passant ?
+ {
+ capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S);
+
+ assert(to == st->epSquare);
+ assert(relative_rank(opposite_color(them), to) == RANK_6);
+ assert(piece_on(to) == EMPTY);
+ assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
+
+ board[capsq] = EMPTY;
+ }
+
// Remove captured piece
- clear_bit(&(byColorBB[them]), to);
- clear_bit(&(byTypeBB[capture]), to);
+ clear_bit(&(byColorBB[them]), capsq);
+ clear_bit(&(byTypeBB[capture]), capsq);
+ clear_bit(&(byTypeBB[0]), capsq);
// Update hash key
- st->key ^= zobrist[them][capture][to];
-
- // If the captured piece was a pawn, update pawn hash key
- if (capture == PAWN)
- st->pawnKey ^= zobrist[them][PAWN][to];
+ key ^= zobrist[them][capture][capsq];
// Update incremental scores
- st->mgValue -= pst<MidGame>(them, capture, to);
- st->egValue -= pst<EndGame>(them, capture, to);
+ st->value -= pst(them, capture, capsq);
- // Update material
- if (capture != PAWN)
- npMaterial[them] -= piece_value_midgame(capture);
+ // If the captured piece was a pawn, update pawn hash key,
+ // otherwise update non-pawn material.
+ if (capture == PAWN)
+ st->pawnKey ^= zobrist[them][PAWN][capsq];
+ else
+ st->npMaterial[them] -= piece_value_midgame(capture);
// Update material hash key
st->materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
// Update piece count
pieceCount[them][capture]--;
- // Update piece list
- pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
- index[pieceList[them][capture][index[to]]] = index[to];
+ // Update piece list, move the last piece at index[capsq] position
+ //
+ // WARNING: This is a not perfectly revresible operation. When we
+ // will reinsert the captured piece in undo_move() we will put it
+ // at the end of the list and not in its original place, it means
+ // index[] and pieceList[] are not guaranteed to be invariant to a
+ // do_move() + undo_move() sequence.
+ Square lastPieceSquare = pieceList[them][capture][pieceCount[them][capture]];
+ index[lastPieceSquare] = index[capsq];
+ pieceList[them][capture][index[lastPieceSquare]] = lastPieceSquare;
+ pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE;
// Reset rule 50 counter
st->rule50 = 0;
void Position::do_castle_move(Move m) {
- assert(is_ok());
assert(move_is_ok(m));
assert(move_is_castle(m));
Color us = side_to_move();
Color them = opposite_color(us);
+ // Reset capture field
+ st->capture = NO_PIECE_TYPE;
+
// Find source squares for king and rook
Square kfrom = move_from(m);
Square rfrom = move_to(m); // HACK: See comment at beginning of function
rto = relative_square(us, SQ_D1);
}
- // Remove pieces from source squares
+ // 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(&(byTypeBB[ROOK]), rfrom);
clear_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
- // Put pieces on destination 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(&(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);
board[kfrom] = board[rfrom] = EMPTY;
- board[kto] = piece_of_color_and_type(us, KING);
- board[rto] = piece_of_color_and_type(us, ROOK);
-
- // Update king square
- kingSquare[us] = kto;
+ board[kto] = king;
+ board[rto] = rook;
// Update piece lists
pieceList[us][KING][index[kfrom]] = kto;
pieceList[us][ROOK][index[rfrom]] = rto;
- int tmp = index[rfrom];
+ int tmp = index[rfrom]; // In Chess960 could be rto == kfrom
index[kto] = index[kfrom];
index[rto] = tmp;
// Update incremental scores
- st->mgValue -= pst<MidGame>(us, KING, kfrom);
- st->mgValue += pst<MidGame>(us, KING, kto);
- st->egValue -= pst<EndGame>(us, KING, kfrom);
- st->egValue += pst<EndGame>(us, KING, kto);
- st->mgValue -= pst<MidGame>(us, ROOK, rfrom);
- st->mgValue += pst<MidGame>(us, ROOK, rto);
- st->egValue -= pst<EndGame>(us, ROOK, rfrom);
- st->egValue += pst<EndGame>(us, ROOK, rto);
+ st->value += pst_delta(king, kfrom, kto);
+ st->value += pst_delta(rook, rfrom, rto);
// Update hash key
st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto];
st->rule50 = 0;
// Update checkers BB
- st->checkersBB = attacks_to(king_square(them), us);
-}
-
+ st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us);
-/// Position::do_promotion_move() is a private method used to make a promotion
-/// move. It is called from the main Position::do_move function.
-
-void Position::do_promotion_move(Move m) {
-
- Color us, them;
- Square from, to;
- PieceType promotion;
+ // Finish
+ sideToMove = opposite_color(sideToMove);
+ st->value += (sideToMove == WHITE ? TempoValue : -TempoValue);
assert(is_ok());
- assert(move_is_ok(m));
- assert(move_promotion(m));
-
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
-
- assert(relative_rank(us, to) == RANK_8);
- assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
- assert(color_of_piece_on(to) == them || square_is_empty(to));
-
- st->capture = type_of_piece_on(to);
-
- if (st->capture)
- do_capture_move(st->capture, them, to);
-
- // Remove pawn
- clear_bit(&(byColorBB[us]), from);
- clear_bit(&(byTypeBB[PAWN]), from);
- clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- board[from] = EMPTY;
-
- // Insert promoted piece
- promotion = move_promotion(m);
- assert(promotion >= KNIGHT && promotion <= QUEEN);
- set_bit(&(byColorBB[us]), to);
- set_bit(&(byTypeBB[promotion]), to);
- set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
- board[to] = piece_of_color_and_type(us, promotion);
-
- // Update hash key
- st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][promotion][to];
-
- // Update pawn hash key
- st->pawnKey ^= zobrist[us][PAWN][from];
+}
- // Update material key
- st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]];
- st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1];
- // Update piece counts
- pieceCount[us][PAWN]--;
- pieceCount[us][promotion]++;
+/// Position::undo_move() unmakes a move. When it returns, the position should
+/// be restored to exactly the same state as before the move was made.
- // Update piece lists
- pieceList[us][PAWN][index[from]] = pieceList[us][PAWN][pieceCount[us][PAWN]];
- index[pieceList[us][PAWN][index[from]]] = index[from];
- pieceList[us][promotion][pieceCount[us][promotion] - 1] = to;
- index[to] = pieceCount[us][promotion] - 1;
+void Position::undo_move(Move m) {
- // Update incremental scores
- st->mgValue -= pst<MidGame>(us, PAWN, from);
- st->mgValue += pst<MidGame>(us, promotion, to);
- st->egValue -= pst<EndGame>(us, PAWN, from);
- st->egValue += pst<EndGame>(us, promotion, to);
+ assert(is_ok());
+ assert(move_is_ok(m));
- // Update material
- npMaterial[us] += piece_value_midgame(promotion);
+ gamePly--;
+ sideToMove = opposite_color(sideToMove);
- // Clear the en passant square
- if (st->epSquare != SQ_NONE)
+ if (move_is_castle(m))
{
- st->key ^= zobEp[st->epSquare];
- st->epSquare = SQ_NONE;
+ undo_castle_move(m);
+ return;
}
- // Update castle rights
- st->key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[to];
- st->key ^= zobCastle[st->castleRights];
-
- // Reset rule 50 counter
- st->rule50 = 0;
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square to = move_to(m);
+ bool ep = move_is_ep(m);
+ bool pm = move_is_promotion(m);
- // Update checkers BB
- st->checkersBB = attacks_to(king_square(them), us);
-}
+ PieceType pt = type_of_piece_on(to);
+ assert(square_is_empty(from));
+ 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(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN));
-/// Position::do_ep_move() is a private method used to make an en passant
-/// capture. It is called from the main Position::do_move function.
+ if (pm) // promotion ?
+ {
+ PieceType promotion = move_promotion_piece(m);
+ pt = PAWN;
+
+ assert(promotion >= KNIGHT && promotion <= QUEEN);
+ assert(piece_on(to) == piece_of_color_and_type(us, promotion));
+
+ // Replace promoted piece with a pawn
+ clear_bit(&(byTypeBB[promotion]), to);
+ set_bit(&(byTypeBB[PAWN]), to);
+
+ // Update piece counts
+ pieceCount[us][promotion]--;
+ pieceCount[us][PAWN]++;
+
+ // Update piece list replacing promotion piece with a pawn
+ Square lastPromotionSquare = pieceList[us][promotion][pieceCount[us][promotion]];
+ index[lastPromotionSquare] = index[to];
+ pieceList[us][promotion][index[lastPromotionSquare]] = lastPromotionSquare;
+ pieceList[us][promotion][pieceCount[us][promotion]] = SQ_NONE;
+ index[to] = pieceCount[us][PAWN] - 1;
+ pieceList[us][PAWN][index[to]] = to;
+ }
-void Position::do_ep_move(Move m) {
- Color us, them;
- Square from, to, capsq;
+ // 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
- assert(is_ok());
- assert(move_is_ok(m));
- assert(move_is_ep(m));
-
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
- capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
-
- assert(to == st->epSquare);
- assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(to) == EMPTY);
- assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
- assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
-
- // Remove captured piece
- clear_bit(&(byColorBB[them]), capsq);
- clear_bit(&(byTypeBB[PAWN]), capsq);
- clear_bit(&(byTypeBB[0]), capsq); // HACK: byTypeBB[0] == occupied squares
- board[capsq] = EMPTY;
-
- // Remove moving piece from source square
- clear_bit(&(byColorBB[us]), from);
- clear_bit(&(byTypeBB[PAWN]), from);
- clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
-
- // Put moving piece on destination square
- set_bit(&(byColorBB[us]), to);
- set_bit(&(byTypeBB[PAWN]), to);
- set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
- board[to] = board[from];
- board[from] = EMPTY;
-
- // Update material hash key
- st->materialKey ^= zobMaterial[them][PAWN][pieceCount[them][PAWN]];
-
- // Update piece count
- pieceCount[them][PAWN]--;
+ board[from] = piece_of_color_and_type(us, pt);
+ board[to] = EMPTY;
// Update piece list
- pieceList[us][PAWN][index[from]] = to;
- index[to] = index[from];
- pieceList[them][PAWN][index[capsq]] = pieceList[them][PAWN][pieceCount[them][PAWN]];
- index[pieceList[them][PAWN][index[capsq]]] = index[capsq];
-
- // Update hash key
- st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
- st->key ^= zobrist[them][PAWN][capsq];
- st->key ^= zobEp[st->epSquare];
-
- // Update pawn hash key
- st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
- st->pawnKey ^= zobrist[them][PAWN][capsq];
-
- // Update incremental scores
- st->mgValue -= pst<MidGame>(them, PAWN, capsq);
- st->mgValue -= pst<MidGame>(us, PAWN, from);
- st->mgValue += pst<MidGame>(us, PAWN, to);
- st->egValue -= pst<EndGame>(them, PAWN, capsq);
- st->egValue -= pst<EndGame>(us, PAWN, from);
- st->egValue += pst<EndGame>(us, PAWN, to);
-
- // Reset en passant square
- st->epSquare = SQ_NONE;
-
- // Reset rule 50 counter
- st->rule50 = 0;
+ index[from] = index[to];
+ pieceList[us][pt][index[from]] = from;
- // Update checkers BB
- st->checkersBB = attacks_to(king_square(them), us);
-}
+ if (st->capture)
+ {
+ Square capsq = to;
+ if (ep)
+ capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
-/// Position::undo_move() unmakes a move. When it returns, the position should
-/// be restored to exactly the same state as before the move was made.
+ assert(st->capture != KING);
+ assert(!ep || square_is_empty(capsq));
-void Position::undo_move(Move m) {
+ // Restore the captured piece
+ set_bit(&(byColorBB[them]), capsq);
+ set_bit(&(byTypeBB[st->capture]), capsq);
+ set_bit(&(byTypeBB[0]), capsq);
- assert(is_ok());
- assert(move_is_ok(m));
+ board[capsq] = piece_of_color_and_type(them, st->capture);
- gamePly--;
- sideToMove = opposite_color(sideToMove);
+ // Update piece count
+ pieceCount[them][st->capture]++;
- if (move_is_castle(m))
- undo_castle_move(m);
- else if (move_promotion(m))
- undo_promotion_move(m);
- else if (move_is_ep(m))
- undo_ep_move(m);
- else
- {
- Color us, them;
- Square from, to;
- PieceType piece;
-
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
-
- assert(piece_on(from) == EMPTY);
- assert(color_of_piece_on(to) == us);
-
- // Put the piece back at the source square
- piece = type_of_piece_on(to);
- set_bit(&(byColorBB[us]), from);
- set_bit(&(byTypeBB[piece]), from);
- set_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- board[from] = piece_of_color_and_type(us, piece);
-
- // Clear the destination square
- clear_bit(&(byColorBB[us]), to);
- clear_bit(&(byTypeBB[piece]), to);
- clear_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
-
- // If the moving piece was a king, update the king square
- if (piece == KING)
- kingSquare[us] = from;
-
- // Update piece list
- pieceList[us][piece][index[to]] = from;
- index[from] = index[to];
-
- if (st->capture)
- {
- assert(st->capture != KING);
-
- // Replace the captured piece
- set_bit(&(byColorBB[them]), to);
- set_bit(&(byTypeBB[st->capture]), to);
- set_bit(&(byTypeBB[0]), to);
- board[to] = piece_of_color_and_type(them, st->capture);
-
- // Update material
- if (st->capture != PAWN)
- npMaterial[them] += piece_value_midgame(st->capture);
-
- // Update piece list
- pieceList[them][st->capture][pieceCount[them][st->capture]] = to;
- index[to] = pieceCount[them][st->capture];
-
- // Update piece count
- pieceCount[them][st->capture]++;
- } else
- board[to] = EMPTY;
+ // Update piece list, add a new captured piece in capsq square
+ index[capsq] = pieceCount[them][st->capture] - 1;
+ pieceList[them][st->capture][index[capsq]] = capsq;
}
// Finally point our state pointer back to the previous state
assert(piece_on(kto) == piece_of_color_and_type(us, KING));
assert(piece_on(rto) == piece_of_color_and_type(us, ROOK));
- // Remove pieces from destination squares
+ // 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(&(byTypeBB[ROOK]), rto);
clear_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
- // Put pieces on source 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
board[rfrom] = piece_of_color_and_type(us, ROOK);
board[kfrom] = piece_of_color_and_type(us, KING);
- // Update king square
- kingSquare[us] = kfrom;
-
// Update piece lists
pieceList[us][KING][index[kto]] = kfrom;
pieceList[us][ROOK][index[rto]] = rfrom;
- int tmp = index[rto]; // Necessary because we may have rto == kfrom in FRC.
+ int tmp = index[rto]; // In Chess960 could be rto == kfrom
index[kfrom] = index[kto];
index[rfrom] = tmp;
-}
-
-
-/// Position::undo_promotion_move() is a private method used to unmake a
-/// promotion move. It is called from the main Position::do_move
-/// function.
-
-void Position::undo_promotion_move(Move m) {
-
- Color us, them;
- Square from, to;
- PieceType promotion;
-
- assert(move_is_ok(m));
- assert(move_promotion(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,
- // so the code below is correct.
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
-
- assert(relative_rank(us, to) == RANK_8);
- assert(piece_on(from) == EMPTY);
-
- // Remove promoted piece
- promotion = move_promotion(m);
- assert(piece_on(to)==piece_of_color_and_type(us, promotion));
- assert(promotion >= KNIGHT && promotion <= QUEEN);
- clear_bit(&(byColorBB[us]), to);
- clear_bit(&(byTypeBB[promotion]), to);
- clear_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
-
- // Insert pawn at source square
- set_bit(&(byColorBB[us]), from);
- set_bit(&(byTypeBB[PAWN]), from);
- set_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- board[from] = piece_of_color_and_type(us, PAWN);
-
- // Update material
- npMaterial[us] -= piece_value_midgame(promotion);
-
- // Update piece list
- pieceList[us][PAWN][pieceCount[us][PAWN]] = from;
- index[from] = pieceCount[us][PAWN];
- pieceList[us][promotion][index[to]] =
- pieceList[us][promotion][pieceCount[us][promotion] - 1];
- index[pieceList[us][promotion][index[to]]] = index[to];
-
- // Update piece counts
- pieceCount[us][promotion]--;
- pieceCount[us][PAWN]++;
-
- if (st->capture)
- {
- assert(st->capture != KING);
-
- // Insert captured piece:
- set_bit(&(byColorBB[them]), to);
- set_bit(&(byTypeBB[st->capture]), to);
- set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
- board[to] = piece_of_color_and_type(them, st->capture);
-
- // Update material. Because the move is a promotion move, we know
- // that the captured piece cannot be a pawn.
- assert(st->capture != PAWN);
- npMaterial[them] += piece_value_midgame(st->capture);
-
- // Update piece list
- pieceList[them][st->capture][pieceCount[them][st->capture]] = to;
- index[to] = pieceCount[them][st->capture];
-
- // Update piece count
- pieceCount[them][st->capture]++;
- } else
- board[to] = EMPTY;
-}
-
-
-/// Position::undo_ep_move() is a private method used to unmake an en passant
-/// capture. It is called from the main Position::undo_move function.
-
-void Position::undo_ep_move(Move m) {
-
- assert(move_is_ok(m));
- assert(move_is_ep(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,
- // so the code below is correct.
- Color us = side_to_move();
- Color them = opposite_color(us);
- Square from = move_from(m);
- Square to = move_to(m);
- Square capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
-
- assert(to == st->previous->epSquare);
- assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(to) == piece_of_color_and_type(us, PAWN));
- assert(piece_on(from) == EMPTY);
- assert(piece_on(capsq) == EMPTY);
-
- // Replace captured piece
- set_bit(&(byColorBB[them]), capsq);
- set_bit(&(byTypeBB[PAWN]), capsq);
- set_bit(&(byTypeBB[0]), capsq);
- board[capsq] = piece_of_color_and_type(them, PAWN);
-
- // Remove moving piece from destination square
- clear_bit(&(byColorBB[us]), to);
- clear_bit(&(byTypeBB[PAWN]), to);
- clear_bit(&(byTypeBB[0]), to);
- board[to] = EMPTY;
- // Replace moving piece at source square
- set_bit(&(byColorBB[us]), from);
- set_bit(&(byTypeBB[PAWN]), from);
- set_bit(&(byTypeBB[0]), from);
- board[from] = piece_of_color_and_type(us, PAWN);
-
- // Update piece list:
- pieceList[us][PAWN][index[to]] = from;
- index[from] = index[to];
- pieceList[them][PAWN][pieceCount[them][PAWN]] = capsq;
- index[capsq] = pieceCount[them][PAWN];
+ // Finally point our state pointer back to the previous state
+ st = st->previous;
- // Update piece count:
- pieceCount[them][PAWN]++;
+ assert(is_ok());
}
assert(!is_check());
// Back up the information necessary to undo the null move to the supplied
- // StateInfo object. In the case of a null move, the only thing we need to
- // remember is the last move made and the en passant square.
+ // StateInfo object.
// Note that differently from normal case here backupSt is actually used as
// a backup storage not as a new state to be used.
- backupSt.lastMove = st->lastMove;
+ backupSt.key = st->key;
backupSt.epSquare = st->epSquare;
+ backupSt.value = st->value;
backupSt.previous = st->previous;
+ backupSt.pliesFromNull = st->pliesFromNull;
st->previous = &backupSt;
// Save the current key to the history[] array, in order to be able to
history[gamePly] = st->key;
// Update the necessary information
- sideToMove = opposite_color(sideToMove);
if (st->epSquare != SQ_NONE)
st->key ^= zobEp[st->epSquare];
+ st->key ^= zobSideToMove;
+ TT.prefetch(st->key);
+
+ sideToMove = opposite_color(sideToMove);
st->epSquare = SQ_NONE;
st->rule50++;
+ st->pliesFromNull = 0;
+ st->value += (sideToMove == WHITE) ? TempoValue : -TempoValue;
gamePly++;
- st->key ^= zobSideToMove;
-
- st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
- st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
-
- assert(is_ok());
}
assert(!is_check());
// Restore information from the our backup StateInfo object
- st->lastMove = st->previous->lastMove;
- st->epSquare = st->previous->epSquare;
- st->previous = st->previous->previous;
-
- if (st->epSquare != SQ_NONE)
- st->key ^= zobEp[st->epSquare];
+ StateInfo* backupSt = st->previous;
+ st->key = backupSt->key;
+ st->epSquare = backupSt->epSquare;
+ st->value = backupSt->value;
+ st->previous = backupSt->previous;
+ st->pliesFromNull = backupSt->pliesFromNull;
// Update the necessary information
sideToMove = opposite_color(sideToMove);
st->rule50--;
gamePly--;
- st->key ^= zobSideToMove;
+}
- st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
- st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
- assert(is_ok());
+///
+PieceType Position::captured_piece() const {
+ return st->capture;
}
-
/// Position::see() is a static exchange evaluator: It tries to estimate the
/// material gain or loss resulting from a move. There are three versions of
/// this function: One which takes a destination square as input, one takes a
return see(move_from(m), move_to(m));
}
+int Position::see_sign(Move m) const {
+
+ assert(move_is_ok(m));
+
+ Square from = move_from(m);
+ Square to = move_to(m);
+
+ // Early return if SEE cannot be negative because capturing piece value
+ // is not bigger then captured one.
+ if ( midgame_value_of_piece_on(from) <= midgame_value_of_piece_on(to)
+ && type_of_piece_on(from) != KING)
+ return 1;
+
+ return see(from, to);
+}
+
int Position::see(Square from, Square to) const {
// Material values
0, 0
};
- Bitboard attackers, stmAttackers, occ, b;
+ Bitboard attackers, stmAttackers, b;
assert(square_is_ok(from) || from == SQ_NONE);
assert(square_is_ok(to));
// Initialize pieces
Piece piece = piece_on(from);
Piece capture = piece_on(to);
+ Bitboard occ = occupied_squares();
- // Find all attackers to the destination square, with the moving piece
- // removed, but possibly an X-ray attacker added behind it.
- occ = occupied_squares();
+ // King cannot be recaptured
+ if (type_of_piece(piece) == KING)
+ return seeValues[capture];
// Handle en passant moves
if (st->epSquare == to && type_of_piece_on(from) == PAWN)
while (true)
{
+ // Find all attackers to the destination square, with the moving piece
+ // removed, but possibly an X-ray attacker added behind it.
clear_bit(&occ, from);
- attackers = (rook_attacks_bb(to, occ) & rooks_and_queens())
- | (bishop_attacks_bb(to, occ) & bishops_and_queens())
- | (piece_attacks<KNIGHT>(to) & knights())
- | (piece_attacks<KING>(to) & kings())
- | (pawn_attacks(WHITE, to) & pawns(BLACK))
- | (pawn_attacks(BLACK, to) & pawns(WHITE));
+ attackers = (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
+ | (bishop_attacks_bb(to, occ) & 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));
if (from != SQ_NONE)
break;
// Locate the least valuable attacker to the destination square
// and use it to initialize from square.
+ stmAttackers = attackers & pieces_of_color(us);
PieceType pt;
- for (pt = PAWN; !(attackers & pieces_of_color_and_type(us, pt)); pt++)
+ for (pt = PAWN; !(stmAttackers & pieces(pt)); pt++)
assert(pt < KING);
- from = first_1(attackers & pieces_of_color_and_type(us, pt));
+ from = first_1(stmAttackers & pieces(pt));
piece = piece_on(from);
}
// Locate the least valuable attacker for the side to move. The loop
// below looks like it is potentially infinite, but it isn't. We know
// that the side to move still has at least one attacker left.
- for (pt = PAWN; !(stmAttackers & pieces_of_type(pt)); pt++)
+ for (pt = PAWN; !(stmAttackers & pieces(pt)); pt++)
assert(pt < KING);
// Remove the attacker we just found from the 'attackers' bitboard,
// and scan for new X-ray attacks behind the attacker.
- b = stmAttackers & pieces_of_type(pt);
+ b = stmAttackers & pieces(pt);
occ ^= (b & (~b + 1));
- attackers |= (rook_attacks_bb(to, occ) & rooks_and_queens())
- | (bishop_attacks_bb(to, occ) & bishops_and_queens());
+ attackers |= (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
+ | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN));
attackers &= occ;
if (pt == KING && stmAttackers)
{
assert(n < 32);
- swapList[n++] = 100;
+ swapList[n++] = QueenValueMidgame*10;
break;
}
} while (stmAttackers);
}
-/// Position::setStartState() copies the content of the argument
-/// inside startState and makes st point to it. This is needed
-/// when the st pointee could become stale, as example because
-/// the caller is about to going out of scope.
-
-void Position::setStartState(const StateInfo& s) {
-
- startState = s;
- st = &startState;
-}
-
-
/// Position::clear() erases the position object to a pristine state, with an
/// empty board, white to move, and no castling rights.
memset(st, 0, sizeof(StateInfo));
st->epSquare = SQ_NONE;
- memset(index, 0, sizeof(int) * 64);
- memset(byColorBB, 0, sizeof(Bitboard) * 2);
+ 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] = EMPTY;
- for (int i = 0; i < 7; i++)
- {
- byTypeBB[i] = EmptyBoardBB;
- pieceCount[0][i] = pieceCount[1][i] = 0;
- for (int j = 0; j < 8; j++)
+ for (int i = 0; i < 8; i++)
+ for (int j = 0; j < 16; j++)
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
- }
sideToMove = WHITE;
gamePly = 0;
set_bit(&byTypeBB[0], s); // HACK: byTypeBB[0] contains all occupied squares.
pieceCount[c][pt]++;
-
- if (pt == KING)
- kingSquare[c] = s;
}
for (Color c = WHITE; c <= BLACK; c++)
{
- b = pawns(c);
- while(b)
+ b = pieces(PAWN, c);
+ while (b)
{
s = pop_1st_bit(&b);
result ^= zobrist[c][PAWN][s];
/// game and the endgame. These functions are used to initialize the incremental
/// scores when a new position is set up, and to verify that the scores are correctly
/// updated by do_move and undo_move when the program is running in debug mode.
-template<Position::GamePhase Phase>
-Value Position::compute_value() const {
+Score Position::compute_value() const {
- Value result = Value(0);
+ Score result = make_score(0, 0);
Bitboard b;
Square s;
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
{
- b = pieces_of_color_and_type(c, pt);
- while(b)
+ b = pieces(pt, c);
+ while (b)
{
s = pop_1st_bit(&b);
assert(piece_on(s) == piece_of_color_and_type(c, pt));
- result += pst<Phase>(c, pt, s);
+ result += pst(c, pt, s);
}
}
- const Value TempoValue = (Phase == MidGame ? TempoValueMidgame : TempoValueEndgame);
- result += (side_to_move() == WHITE)? TempoValue / 2 : -TempoValue / 2;
+ result += (side_to_move() == WHITE ? TempoValue / 2 : -TempoValue / 2);
return result;
}
for (PieceType pt = KNIGHT; pt <= QUEEN; pt++)
{
- Bitboard b = pieces_of_color_and_type(c, pt);
+ Bitboard b = pieces(pt, c);
while (b)
{
assert(piece_on(first_1(b)) == piece_of_color_and_type(c, pt));
/// 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.
+// FIXME: Currently we are not handling 50 move rule correctly when in check
bool Position::is_draw() const {
// Draw by material?
- if ( !pawns()
+ if ( !pieces(PAWN)
&& (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMidgame))
return true;
return true;
// Draw by repetition?
- for (int i = 2; i < Min(gamePly, st->rule50); i += 2)
+ for (int i = 4; i <= Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2)
if (history[gamePly - i] == st->key)
return true;
bool Position::is_mate() const {
MoveStack moves[256];
-
- return is_check() && !generate_evasions(*this, moves, pinned_pieces(sideToMove));
+ return is_check() && (generate_moves(*this, moves, false) == moves);
}
do_null_move(st1);
MoveStack mlist[120];
- int count;
bool result = false;
- Bitboard dc = discovered_check_candidates(sideToMove);
Bitboard pinned = pinned_pieces(sideToMove);
// Generate pseudo-legal non-capture and capture check moves
- count = generate_non_capture_checks(*this, mlist, dc);
- count += generate_captures(*this, mlist + count);
+ MoveStack* last = generate_non_capture_checks(*this, mlist);
+ last = generate_captures(*this, last);
// Loop through the moves, and see if one of them is mate
- for (int i = 0; i < count; i++)
+ for (MoveStack* cur = mlist; cur != last; cur++)
{
- Move move = mlist[i].move;
-
+ Move move = cur->move;
if (!pl_move_is_legal(move, pinned))
continue;
for (int i = 0; i < 16; i++)
zobMaterial[0][KING][i] = zobMaterial[1][KING][i] = Key(0ULL);
+
+ zobExclusion = genrand_int64();
}
for (Piece p = WP; p <= WK; p++)
{
i = (r == 0)? 0 : (genrand_int32() % (r*2) - r);
- MgPieceSquareTable[p][s] = Value(MgPST[p][s] + i);
- EgPieceSquareTable[p][s] = Value(EgPST[p][s] + i);
+ PieceSquareTable[p][s] = make_score(MgPST[p][s] + i, EgPST[p][s] + i);
}
for (Square s = SQ_A1; s <= SQ_H8; s++)
for (Piece p = BP; p <= BK; p++)
- {
- MgPieceSquareTable[p][s] = -MgPieceSquareTable[p-8][flip_square(s)];
- EgPieceSquareTable[p][s] = -EgPieceSquareTable[p-8][flip_square(s)];
- }
+ PieceSquareTable[p][s] = -PieceSquareTable[p-8][flip_square(s)];
}
/// 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::flipped_copy(const Position& pos) {
assert(pos.is_ok());
st->materialKey = compute_material_key();
// Incremental scores
- st->mgValue = compute_value<MidGame>();
- st->egValue = compute_value<EndGame>();
+ st->value = compute_value();
// Material
- npMaterial[WHITE] = compute_non_pawn_material(WHITE);
- npMaterial[BLACK] = compute_non_pawn_material(BLACK);
+ st->npMaterial[WHITE] = compute_non_pawn_material(WHITE);
+ st->npMaterial[BLACK] = compute_non_pawn_material(BLACK);
assert(is_ok());
}
static const bool debugNonPawnMaterial = false;
static const bool debugPieceCounts = false;
static const bool debugPieceList = false;
+ static const bool debugCastleSquares = false;
if (failedStep) *failedStep = 1;
Color us = side_to_move();
Color them = opposite_color(us);
Square ksq = king_square(them);
- if (square_is_attacked(ksq, us))
+ if (attackers_to(ksq) & pieces_of_color(us))
return false;
}
// Separate piece type bitboards must have empty intersections
for (PieceType p1 = PAWN; p1 <= KING; p1++)
for (PieceType p2 = PAWN; p2 <= KING; p2++)
- if (p1 != p2 && (pieces_of_type(p1) & pieces_of_type(p2)))
+ if (p1 != p2 && (pieces(p1) & pieces(p2)))
return false;
}
// Incremental eval OK?
if (failedStep) (*failedStep)++;
- if (debugIncrementalEval)
- {
- if (st->mgValue != compute_value<MidGame>())
- return false;
-
- if (st->egValue != compute_value<EndGame>())
- return false;
- }
+ if (debugIncrementalEval && st->value != compute_value())
+ return false;
// Non-pawn material OK?
if (failedStep) (*failedStep)++;
if (debugNonPawnMaterial)
{
- if (npMaterial[WHITE] != compute_non_pawn_material(WHITE))
+ if (st->npMaterial[WHITE] != compute_non_pawn_material(WHITE))
return false;
- if (npMaterial[BLACK] != compute_non_pawn_material(BLACK))
+ if (st->npMaterial[BLACK] != compute_non_pawn_material(BLACK))
return false;
}
if (debugPieceCounts)
for (Color c = WHITE; c <= BLACK; c++)
for (PieceType pt = PAWN; pt <= KING; pt++)
- if (pieceCount[c][pt] != count_1s(pieces_of_color_and_type(c, pt)))
+ if (pieceCount[c][pt] != count_1s(pieces(pt, c)))
return false;
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++)
+ 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))
return false;
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))
+ return false;
+ if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != piece_of_color_and_type(c, 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