key = compute_key();
pawnKey = compute_pawn_key();
materialKey = compute_material_key();
- mgValue = compute_mg_value();
- egValue = compute_eg_value();
+ mgValue = compute_value<MidGame>();
+ egValue = compute_value<EndGame>();
npMaterial[WHITE] = compute_non_pawn_material(WHITE);
npMaterial[BLACK] = compute_non_pawn_material(BLACK);
}
}
-/// Position::backup() is called when making a move. All information
-/// necessary to restore the position when the move is later unmade
-/// is saved to an UndoInfo object. The function Position::restore
-/// does the reverse operation: When one does a backup followed by
-/// a restore with the same UndoInfo object, the position is restored
-/// to the state before backup was called.
-
-void Position::backup(UndoInfo& u) const {
-
- u.castleRights = castleRights;
- u.epSquare = epSquare;
- u.checkersBB = checkersBB;
- u.key = key;
- u.pawnKey = pawnKey;
- u.materialKey = materialKey;
- u.rule50 = rule50;
- u.lastMove = lastMove;
- u.mgValue = mgValue;
- u.egValue = egValue;
- u.capture = NO_PIECE_TYPE;
-
- for (Color c = WHITE; c <= BLACK; c++)
- {
- u.pinners[c] = pinners[c];
- u.pinned[c] = pinned[c];
- u.dcCandidates[c] = dcCandidates[c];
- }
-}
-
-
-/// Position::restore() is called when unmaking a move. It copies back
-/// the information backed up during a previous call to Position::backup.
-
-void Position::restore(const UndoInfo& u) {
-
- castleRights = u.castleRights;
- epSquare = u.epSquare;
- checkersBB = u.checkersBB;
- key = u.key;
- pawnKey = u.pawnKey;
- materialKey = u.materialKey;
- rule50 = u.rule50;
- lastMove = u.lastMove;
- mgValue = u.mgValue;
- egValue = u.egValue;
- // u.capture is restored in undo_move()
-
- for (Color c = WHITE; c <= BLACK; c++)
- {
- pinners[c] = u.pinners[c];
- pinned[c] = u.pinned[c];
- dcCandidates[c] = u.dcCandidates[c];
- }
-}
-
-
/// Position::update_checkers() is a private method to udpate chekers info
template<PieceType Piece>
/// Position::do_move() makes a move, and backs up all information necessary
/// to undo the move to an UndoInfo object. The move is assumed to be legal.
/// Pseudo-legal moves should be filtered out before this function is called.
-/// There are two versions of this function, one which takes only the move and
-/// the UndoInfo as input, and one which takes a third parameter, a bitboard of
-/// discovered check candidates. The second version is faster, because knowing
-/// the discovered check candidates makes it easier to update the checkersBB
-/// member variable in the position object.
void Position::do_move(Move m, UndoInfo& u) {
- do_move(m, u, discovered_check_candidates(side_to_move()));
-}
-
-void Position::do_move(Move m, UndoInfo& u, Bitboard dc) {
-
assert(is_ok());
assert(move_is_ok(m));
+ // Get now the current (pre-move) dc candidates that we will use
+ // in update_checkers().
+ Bitboard oldDcCandidates = discovered_check_candidates(side_to_move());
+
// Back up the necessary information to our UndoInfo object (except the
// captured piece, which is taken care of later.
- backup(u);
+ u = undoInfoUnion;
+ u.capture = NO_PIECE_TYPE;
+ previous = &u;
// Save the current key to the history[] array, in order to be able to
// detect repetition draws.
if (move_is_castle(m))
do_castle_move(m);
else if (move_promotion(m))
- do_promotion_move(m, u);
+ do_promotion_move(m);
else if (move_is_ep(m))
do_ep_move(m);
else
key ^= zobrist[us][piece][from] ^ zobrist[us][piece][to];
// Update incremental scores
- mgValue -= mg_pst(us, piece, from);
- mgValue += mg_pst(us, piece, to);
- egValue -= eg_pst(us, piece, from);
- egValue += eg_pst(us, piece, to);
+ mgValue -= pst<MidGame>(us, piece, from);
+ mgValue += pst<MidGame>(us, piece, to);
+ egValue -= pst<EndGame>(us, piece, from);
+ egValue += pst<EndGame>(us, piece, to);
// If the moving piece was a king, update the king square
if (piece == KING)
Square ksq = king_square(them);
switch (piece)
{
- case PAWN: update_checkers<PAWN>(&checkersBB, ksq, from, to, dc); break;
- case KNIGHT: update_checkers<KNIGHT>(&checkersBB, ksq, from, to, dc); break;
- case BISHOP: update_checkers<BISHOP>(&checkersBB, ksq, from, to, dc); break;
- case ROOK: update_checkers<ROOK>(&checkersBB, ksq, from, to, dc); break;
- case QUEEN: update_checkers<QUEEN>(&checkersBB, ksq, from, to, dc); break;
- case KING: update_checkers<KING>(&checkersBB, ksq, from, to, dc); break;
+ case PAWN: update_checkers<PAWN>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case KNIGHT: update_checkers<KNIGHT>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case BISHOP: update_checkers<BISHOP>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case ROOK: update_checkers<ROOK>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case QUEEN: update_checkers<QUEEN>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case KING: update_checkers<KING>(&checkersBB, ksq, from, to, oldDcCandidates); break;
default: assert(false); break;
}
}
pawnKey ^= zobrist[them][PAWN][to];
// Update incremental scores
- mgValue -= mg_pst(them, capture, to);
- egValue -= eg_pst(them, capture, to);
+ mgValue -= pst<MidGame>(them, capture, to);
+ egValue -= pst<EndGame>(them, capture, to);
assert(!move_promotion(m) || capture != PAWN);
index[rto] = tmp;
// Update incremental scores
- mgValue -= mg_pst(us, KING, kfrom);
- mgValue += mg_pst(us, KING, kto);
- egValue -= eg_pst(us, KING, kfrom);
- egValue += eg_pst(us, KING, kto);
- mgValue -= mg_pst(us, ROOK, rfrom);
- mgValue += mg_pst(us, ROOK, rto);
- egValue -= eg_pst(us, ROOK, rfrom);
- egValue += eg_pst(us, ROOK, rto);
+ mgValue -= pst<MidGame>(us, KING, kfrom);
+ mgValue += pst<MidGame>(us, KING, kto);
+ egValue -= pst<EndGame>(us, KING, kfrom);
+ egValue += pst<EndGame>(us, KING, kto);
+ mgValue -= pst<MidGame>(us, ROOK, rfrom);
+ mgValue += pst<MidGame>(us, ROOK, rto);
+ egValue -= pst<EndGame>(us, ROOK, rfrom);
+ egValue += pst<EndGame>(us, ROOK, rto);
// Update hash key
key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto];
/// UndoInfo object, which has been initialized in Position::do_move, is
/// used to store the captured piece (if any).
-void Position::do_promotion_move(Move m, UndoInfo &u) {
+void Position::do_promotion_move(Move m) {
Color us, them;
Square from, to;
if (capture)
{
- u.capture = capture;
+ previous->capture = capture;
do_capture_move(m, capture, them, to);
}
index[to] = pieceCount[us][promotion] - 1;
// Update incremental scores
- mgValue -= mg_pst(us, PAWN, from);
- mgValue += mg_pst(us, promotion, to);
- egValue -= eg_pst(us, PAWN, from);
- egValue += eg_pst(us, promotion, to);
+ mgValue -= pst<MidGame>(us, PAWN, from);
+ mgValue += pst<MidGame>(us, promotion, to);
+ egValue -= pst<EndGame>(us, PAWN, from);
+ egValue += pst<EndGame>(us, promotion, to);
// Update material
npMaterial[us] += piece_value_midgame(promotion);
pawnKey ^= zobrist[them][PAWN][capsq];
// Update incremental scores
- mgValue -= mg_pst(them, PAWN, capsq);
- mgValue -= mg_pst(us, PAWN, from);
- mgValue += mg_pst(us, PAWN, to);
- egValue -= eg_pst(them, PAWN, capsq);
- egValue -= eg_pst(us, PAWN, from);
- egValue += eg_pst(us, PAWN, to);
+ mgValue -= pst<MidGame>(them, PAWN, capsq);
+ mgValue -= pst<MidGame>(us, PAWN, from);
+ mgValue += pst<MidGame>(us, PAWN, to);
+ egValue -= pst<EndGame>(them, PAWN, capsq);
+ egValue -= pst<EndGame>(us, PAWN, from);
+ egValue += pst<EndGame>(us, PAWN, to);
// Reset en passant square
epSquare = SQ_NONE;
/// important that Position::undo_move is called with the same move and UndoInfo
/// object as the earlier call to Position::do_move.
-void Position::undo_move(Move m, const UndoInfo &u) {
+void Position::undo_move(Move m) {
assert(is_ok());
assert(move_is_ok(m));
// Restore information from our UndoInfo object (except the captured piece,
// which is taken care of later)
- restore(u);
+ undoInfoUnion = *previous;
if (move_is_castle(m))
undo_castle_move(m);
else if (move_promotion(m))
- undo_promotion_move(m, u);
+ undo_promotion_move(m);
else if (move_is_ep(m))
undo_ep_move(m);
else
{
Color us, them;
Square from, to;
- PieceType piece, capture;
+ PieceType piece;
us = side_to_move();
them = opposite_color(us);
pieceList[us][piece][index[to]] = from;
index[from] = index[to];
- capture = u.capture;
-
if (capture)
{
assert(capture != KING);
/// function. The UndoInfo object, which has been initialized in
/// Position::do_move, is used to put back the captured piece (if any).
-void Position::undo_promotion_move(Move m, const UndoInfo &u) {
+void Position::undo_promotion_move(Move m) {
Color us, them;
Square from, to;
- PieceType capture, promotion;
+ PieceType promotion;
assert(move_is_ok(m));
assert(move_promotion(m));
pieceCount[us][promotion]--;
pieceCount[us][PAWN]++;
- capture = u.capture;
-
if (capture)
{
assert(capture != KING);
assert(!is_check());
// Back up the information necessary to undo the null move to the supplied
- // UndoInfo object. In the case of a null move, the only thing we need to
+ // UndoInfo 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.
u.lastMove = lastMove;
u.epSquare = epSquare;
+ u.previous = previous;
+ previous = &u;
// Save the current key to the history[] array, in order to be able to
// detect repetition draws.
/// Position::undo_null_move() unmakes a "null move".
-void Position::undo_null_move(const UndoInfo &u) {
+void Position::undo_null_move() {
assert(is_ok());
assert(!is_check());
- // Restore information from the supplied UndoInfo object:
- lastMove = u.lastMove;
- epSquare = u.epSquare;
+ // Restore information from the our UndoInfo object
+ lastMove = previous->lastMove;
+ epSquare = previous->epSquare;
+ previous = previous->previous;
+
if (epSquare != SQ_NONE)
key ^= zobEp[epSquare];
- // Update the necessary information.
+ // Update the necessary information
sideToMove = opposite_color(sideToMove);
rule50--;
gamePly--;
epSquare = SQ_NONE;
rule50 = 0;
gamePly = 0;
+ previous = NULL;
}
}
-/// Position::compute_mg_value() and Position::compute_eg_value() compute the
-/// incremental scores for the middle 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.
-
-Value Position::compute_mg_value() const {
+/// Position::compute_value() compute the incremental scores for the middle
+/// 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 {
Value result = Value(0);
Bitboard b;
{
s = pop_1st_bit(&b);
assert(piece_on(s) == piece_of_color_and_type(c, pt));
- result += mg_pst(c, pt, s);
+ result += pst<Phase>(c, pt, s);
}
}
- result += (side_to_move() == WHITE)? TempoValueMidgame / 2 : -TempoValueMidgame / 2;
- return result;
-}
-Value Position::compute_eg_value() const {
-
- Value result = Value(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)
- {
- s = pop_1st_bit(&b);
- assert(piece_on(s) == piece_of_color_and_type(c, pt));
- result += eg_pst(c, pt, s);
- }
- }
- result += (side_to_move() == WHITE)? TempoValueEndgame / 2 : -TempoValueEndgame / 2;
+ const Value TempoValue = (Phase == MidGame ? TempoValueMidgame : TempoValueEndgame);
+ result += (side_to_move() == WHITE)? TempoValue / 2 : -TempoValue / 2;
return result;
}
if (is_mate())
result = true;
- undo_move(mlist[i].move, u2);
+ undo_move(mlist[i].move);
}
// Undo null move, if necessary
if (c != stm)
- undo_null_move(u1);
+ undo_null_move();
return result;
}
materialKey = compute_material_key();
// Incremental scores
- mgValue = compute_mg_value();
- egValue = compute_eg_value();
+ mgValue = compute_value<MidGame>();
+ egValue = compute_value<EndGame>();
// Material
npMaterial[WHITE] = compute_non_pawn_material(WHITE);
if (failedStep) (*failedStep)++;
if (debugIncrementalEval)
{
- if (mgValue != compute_mg_value())
+ if (mgValue != compute_value<MidGame>())
return false;
- if (egValue != compute_eg_value())
+ if (egValue != compute_value<EndGame>())
return false;
}