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Factor out pieceList updating code 

The new Position methods add_piece, move_piece, and remove_piece
now manage the member variables pieceList, pieceCount, and index,
and 9 blocks of code in Position that used to manipulate those
data structures by hand now call the new methods.

There is a slightly slowdown (< 1%) on Clang and on perft,
but the cleanup compensates the little speed loss.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
sf_4_base
Dan Schmidt 2013-07-29 11:44:58 -04:00 committed by Marco Costalba
parent 55948623e7
commit 7b4f5c8f72
2 changed files with 39 additions and 40 deletions
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53
src/position.cpp
View File

@ -797,17 +797,8 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
byTypeBB[capture] ^= capsq;
byColorBB[them] ^= capsq;
// Update piece list, move the last piece at index[capsq] position and
// shrink the list.
//
// WARNING: This is a not reversible 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 lastSquare = pieceList[them][capture][--pieceCount[them][capture]];
index[lastSquare] = index[capsq];
pieceList[them][capture][index[lastSquare]] = lastSquare;
pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE;
// Update piece lists
remove_piece(capsq, them, capture);
// Update material hash key and prefetch access to materialTable
k ^= Zobrist::psq[them][capture][capsq];
@ -853,10 +844,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
board[from] = NO_PIECE;
board[to] = pc;
// Update piece lists, 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;
move_piece(from, to, us, pt);
}
// If the moving piece is a pawn do some special extra work
@ -882,19 +870,14 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI
byTypeBB[promotion] |= to;
board[to] = make_piece(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 lastSquare = pieceList[us][PAWN][--pieceCount[us][PAWN]];
index[lastSquare] = index[to];
pieceList[us][PAWN][index[lastSquare]] = lastSquare;
pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE;
index[to] = pieceCount[us][promotion];
pieceList[us][promotion][index[to]] = to;
// Update piece lists and add a new promotion piece to the list
remove_piece(to, us, PAWN);
add_piece(to, us, promotion);
// Update hash keys
k ^= Zobrist::psq[us][PAWN][to] ^ Zobrist::psq[us][promotion][to];
st->pawnKey ^= Zobrist::psq[us][PAWN][to];
st->materialKey ^= Zobrist::psq[us][promotion][pieceCount[us][promotion]++]
st->materialKey ^= Zobrist::psq[us][promotion][pieceCount[us][promotion]-1]
^ Zobrist::psq[us][PAWN][pieceCount[us][PAWN]];
// Update incremental score
@ -984,14 +967,9 @@ void Position::undo_move(Move m) {
byTypeBB[PAWN] |= to;
board[to] = make_piece(us, PAWN);
// Update piece lists, move the last promoted piece at index[to] position
// and shrink the list. Add a new pawn to the list.
Square lastSquare = pieceList[us][promotion][--pieceCount[us][promotion]];
index[lastSquare] = index[to];
pieceList[us][promotion][index[lastSquare]] = lastSquare;
pieceList[us][promotion][pieceCount[us][promotion]] = SQ_NONE;
index[to] = pieceCount[us][PAWN]++;
pieceList[us][PAWN][index[to]] = to;
// Update piece lists and add new pawn to the list
remove_piece(to, us, promotion);
add_piece(to, us, PAWN);
pt = PAWN;
}
@ -1017,10 +995,7 @@ void Position::undo_move(Move m) {
board[to] = NO_PIECE;
board[from] = make_piece(us, pt);
// Update piece lists, index[to] is not updated and becomes stale. This
// works as long as index[] is accessed just by known occupied squares.
index[from] = index[to];
pieceList[us][pt][index[from]] = from;
move_piece(to, from, us, pt);
}
if (capture)
@ -1045,8 +1020,7 @@ void Position::undo_move(Move m) {
board[capsq] = make_piece(them, capture);
// Update piece list, add a new captured piece in capsq square
index[capsq] = pieceCount[them][capture]++;
pieceList[them][capture][index[capsq]] = capsq;
add_piece(capsq, them, capture);
}
// Finally point our state pointer back to the previous state
@ -1250,8 +1224,7 @@ void Position::put_piece(Piece p, Square s) {
PieceType pt = type_of(p);
board[s] = p;
index[s] = pieceCount[c][pt]++;
pieceList[c][pt][index[s]] = s;
add_piece(s, c, pt);
byTypeBB[ALL_PIECES] |= s;
byTypeBB[pt] |= s;

26
src/position.h
View File

@ -194,6 +194,9 @@ private:
// Helper functions
void do_castle(Square kfrom, Square kto, Square rfrom, Square rto);
Bitboard hidden_checkers(Square ksq, Color c) const;
void remove_piece(Square s, Color c, PieceType pt);
void add_piece(Square s, Color c, PieceType pt);
void move_piece(Square from, Square to, Color c, PieceType pt);
// Computing hash keys from scratch (for initialization and debugging)
Key compute_key() const;
@ -414,4 +417,27 @@ inline Thread* Position::this_thread() const {
return thisThread;
}
inline void Position::add_piece(Square s, Color c, PieceType pt) {
index[s] = pieceCount[c][pt]++;
pieceList[c][pt][index[s]] = s;
}
inline void Position::move_piece(Square from, Square to, Color c, PieceType pt) {
// 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[c][pt][index[to]] = to;
}
inline void Position::remove_piece(Square s, Color c, PieceType pt) {
// WARNING: This is not a reversible operation. If we remove a piece in
// do_move() and then replace it 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 lastSquare = pieceList[c][pt][--pieceCount[c][pt]];
index[lastSquare] = index[s];
pieceList[c][pt][index[lastSquare]] = lastSquare;
pieceList[c][pt][pieceCount[c][pt]] = SQ_NONE;
}
#endif // #ifndef POSITION_H_INCLUDED