HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-22 01:56:58 +08:00
Code Issues Packages Projects Releases Wiki Activity

Remove piece lists

Browse Source 
This patch removes the incrementally updated piece lists from the Position object.

This has been tried before but always failed. My reasons for trying again are:

* 32-bit systems (including phones) are now much less important than they were some years ago (and are absent from fishtest);
* NNUE may have made SF less finely tuned to the order in which moves were generated.

STC:
LLR: 2.94 (-2.94,2.94) {-1.25,0.25}
Total: 55272 W: 5260 L: 5216 D: 44796
Ptnml(0-2): 208, 4147, 18898, 4159, 224
https://tests.stockfishchess.org/tests/view/5fc2986a42a050a89f02c926

LTC:
LLR: 2.96 (-2.94,2.94) {-0.75,0.25}
Total: 16600 W: 673 L: 608 D: 15319
Ptnml(0-2): 14, 533, 7138, 604, 11
https://tests.stockfishchess.org/tests/view/5fc2f98342a050a89f02c95c

closes https://github.com/official-stockfish/Stockfish/pull/3247

Bench: 3940967
This commit is contained in:
syzygy1
2020-11-29 12:05:26 +01:00
committed by Joost VandeVondele
parent 2bc4ae172a
commit 045728a7da
6 changed files with 20 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
src/position.h
View File

@@ -99,7 +99,6 @@ public:
bool empty(Square s) const;
template<PieceType Pt> int count(Color c) const;
template<PieceType Pt> int count() const;
template<PieceType Pt> const Square* squares(Color c) const;
template<PieceType Pt> Square square(Color c) const;
bool is_on_semiopen_file(Color c, Square s) const;
@@ -190,8 +189,6 @@ private:
Bitboard byTypeBB[PIECE_TYPE_NB];
Bitboard byColorBB[COLOR_NB];
int pieceCount[PIECE_NB];
Square pieceList[PIECE_NB][16];
int index[SQUARE_NB];
int castlingRightsMask[SQUARE_NB];
Square castlingRookSquare[CASTLING_RIGHT_NB];
Bitboard castlingPath[CASTLING_RIGHT_NB];
@@ -254,13 +251,9 @@ template<PieceType Pt> inline int Position::count() const {
return count<Pt>(WHITE) + count<Pt>(BLACK);
}
template<PieceType Pt> inline const Square* Position::squares(Color c) const {
return pieceList[make_piece(c, Pt)];
}
template<PieceType Pt> inline Square Position::square(Color c) const {
assert(pieceCount[make_piece(c, Pt)] == 1);
return squares<Pt>(c)[0];
assert(count<Pt>(c) == 1);
return lsb(pieces(c, Pt));
}
inline Square Position::ep_square() const {
@@ -394,35 +387,25 @@ inline void Position::put_piece(Piece pc, Square s) {
board[s] = pc;
byTypeBB[ALL_PIECES] |= byTypeBB[type_of(pc)] |= s;
byColorBB[color_of(pc)] |= s;
index[s] = pieceCount[pc]++;
pieceList[pc][index[s]] = s;
pieceCount[pc]++;
pieceCount[make_piece(color_of(pc), ALL_PIECES)]++;
psq += PSQT::psq[pc][s];
}
inline void Position::remove_piece(Square s) {
// 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 invariant to a do_move() + undo_move() sequence.
Piece pc = board[s];
byTypeBB[ALL_PIECES] ^= s;
byTypeBB[type_of(pc)] ^= s;
byColorBB[color_of(pc)] ^= s;
/* board[s] = NO_PIECE; Not needed, overwritten by the capturing one */
Square lastSquare = pieceList[pc][--pieceCount[pc]];
index[lastSquare] = index[s];
pieceList[pc][index[lastSquare]] = lastSquare;
pieceList[pc][pieceCount[pc]] = SQ_NONE;
pieceCount[pc]--;
pieceCount[make_piece(color_of(pc), ALL_PIECES)]--;
psq -= PSQT::psq[pc][s];
}
inline void Position::move_piece(Square from, Square to) {
// index[from] is not updated and becomes stale. This works as long as index[]
// is accessed just by known occupied squares.
Piece pc = board[from];
Bitboard fromTo = from | to;
byTypeBB[ALL_PIECES] ^= fromTo;
@@ -430,8 +413,6 @@ inline void Position::move_piece(Square from, Square to) {
byColorBB[color_of(pc)] ^= fromTo;
board[from] = NO_PIECE;
board[to] = pc;
index[to] = index[from];
pieceList[pc][index[to]] = to;
psq += PSQT::psq[pc][to] - PSQT::psq[pc][from];
}