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Remove pawn_attacks_bb()

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Generalize attacks_bb() to handle pawns and remove pawn_attacks_bb()

https://tests.stockfishchess.org/tests/view/67e9496231d7cf8afdc44a2e
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 134688 W: 34660 L: 34553 D: 65475
Ptnml(0-2): 298, 14619, 37462, 14608, 357

closes https://github.com/official-stockfish/Stockfish/pull/5947

No functional change
This commit is contained in:
mstembera
2025-04-02 17:39:40 +02:00
committed by Disservin
parent d2cb927a04
commit 1a395f1b56
4 changed files with 15 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/bitboard.cpp
+2 -3
View File
@@ -32,7 +32,6 @@ uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
Bitboard LineBB[SQUARE_NB][SQUARE_NB];
Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
alignas(64) Magic Magics[SQUARE_NB][2];
@@ -86,8 +85,8 @@ void Bitboards::init() {
for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1)
{
PawnAttacks[WHITE][s1] = pawn_attacks_bb<WHITE>(square_bb(s1));
PawnAttacks[BLACK][s1] = pawn_attacks_bb<BLACK>(square_bb(s1));
PseudoAttacks[WHITE][s1] = pawn_attacks_bb<WHITE>(square_bb(s1));
PseudoAttacks[BLACK][s1] = pawn_attacks_bb<BLACK>(square_bb(s1));
for (int step : {-9, -8, -7, -1, 1, 7, 8, 9})
PseudoAttacks[KING][s1] |= safe_destination(s1, step);
src/bitboard.h
+3 -9
View File
@@ -62,7 +62,6 @@ extern uint8_t SquareDistance[SQUARE_NB][SQUARE_NB];
extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
extern Bitboard PawnAttacks[COLOR_NB][SQUARE_NB];
// Magic holds all magic bitboards relevant data for a single square
@@ -155,11 +154,6 @@ constexpr Bitboard pawn_attacks_bb(Bitboard b) {
: shift<SOUTH_WEST>(b) | shift<SOUTH_EAST>(b);
}
inline Bitboard pawn_attacks_bb(Color c, Square s) {
assert(is_ok(s));
return PawnAttacks[c][s];
}
// Returns a bitboard representing an entire line (from board edge
// to board edge) that intersects the two given squares. If the given squares
@@ -216,10 +210,10 @@ inline int edge_distance(File f) { return std::min(f, File(FILE_H - f)); }
// Returns the pseudo attacks of the given piece type
// assuming an empty board.
template<PieceType Pt>
inline Bitboard attacks_bb(Square s) {
inline Bitboard attacks_bb(Square s, Color c = COLOR_NB) {
assert((Pt != PAWN) && (is_ok(s)));
return PseudoAttacks[Pt][s];
assert((Pt != PAWN || c < COLOR_NB) && (is_ok(s)));
return Pt == PAWN ? PseudoAttacks[c][s] : PseudoAttacks[Pt][s];
}
src/movegen.cpp
+1 -1
View File
@@ -134,7 +134,7 @@ ExtMove* generate_pawn_moves(const Position& pos, ExtMove* moveList, Bitboard ta
if (Type == EVASIONS && (target & (pos.ep_square() + Up)))
return moveList;
b1 = pawnsNotOn7 & pawn_attacks_bb(Them, pos.ep_square());
b1 = pawnsNotOn7 & attacks_bb<PAWN>(pos.ep_square(), Them);
assert(b1);
src/position.cpp
+7 -7
View File
@@ -270,7 +270,7 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si) {
// a) side to move have a pawn threatening epSquare
// b) there is an enemy pawn in front of epSquare
// c) there is no piece on epSquare or behind epSquare
enpassant = pawn_attacks_bb(~sideToMove, st->epSquare) & pieces(sideToMove, PAWN)
enpassant = attacks_bb<PAWN>(st->epSquare, ~sideToMove) & pieces(sideToMove, PAWN)
&& (pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove)))
&& !(pieces() & (st->epSquare | (st->epSquare + pawn_push(sideToMove))));
}
@@ -321,7 +321,7 @@ void Position::set_check_info() const {
Square ksq = square<KING>(~sideToMove);
st->checkSquares[PAWN] = pawn_attacks_bb(~sideToMove, ksq);
st->checkSquares[PAWN] = attacks_bb<PAWN>(ksq, ~sideToMove);
st->checkSquares[KNIGHT] = attacks_bb<KNIGHT>(ksq);
st->checkSquares[BISHOP] = attacks_bb<BISHOP>(ksq, pieces());
st->checkSquares[ROOK] = attacks_bb<ROOK>(ksq, pieces());
@@ -487,8 +487,8 @@ Bitboard Position::attackers_to(Square s, Bitboard occupied) const {
return (attacks_bb<ROOK>(s, occupied) & pieces(ROOK, QUEEN))
| (attacks_bb<BISHOP>(s, occupied) & pieces(BISHOP, QUEEN))
| (pawn_attacks_bb(BLACK, s) & pieces(WHITE, PAWN))
| (pawn_attacks_bb(WHITE, s) & pieces(BLACK, PAWN))
| (attacks_bb<PAWN>(s, BLACK) & pieces(WHITE, PAWN))
| (attacks_bb<PAWN>(s, WHITE) & pieces(BLACK, PAWN))
| (attacks_bb<KNIGHT>(s) & pieces(KNIGHT)) | (attacks_bb<KING>(s) & pieces(KING));
}
@@ -498,7 +498,7 @@ bool Position::attackers_to_exist(Square s, Bitboard occupied, Color c) const {
&& (attacks_bb<ROOK>(s, occupied) & pieces(c, ROOK, QUEEN)))
|| ((attacks_bb<BISHOP>(s) & pieces(c, BISHOP, QUEEN))
&& (attacks_bb<BISHOP>(s, occupied) & pieces(c, BISHOP, QUEEN)))
|| (((pawn_attacks_bb(~c, s) & pieces(PAWN)) | (attacks_bb<KNIGHT>(s) & pieces(KNIGHT))
|| (((attacks_bb<PAWN>(s, ~c) & pieces(PAWN)) | (attacks_bb<KNIGHT>(s) & pieces(KNIGHT))
| (attacks_bb<KING>(s) & pieces(KING)))
& pieces(c));
}
@@ -597,7 +597,7 @@ bool Position::pseudo_legal(const Move m) const {
if ((Rank8BB | Rank1BB) & to)
return false;
if (!(pawn_attacks_bb(us, from) & pieces(~us) & to) // Not a capture
if (!(attacks_bb<PAWN>(from, us) & pieces(~us) & to) // Not a capture
&& !((from + pawn_push(us) == to) && empty(to)) // Not a single push
&& !((from + 2 * pawn_push(us) == to) // Not a double push
&& (relative_rank(us, from) == RANK_2) && empty(to) && empty(to - pawn_push(us))))
@@ -812,7 +812,7 @@ DirtyPiece Position::do_move(Move m,
{
// Set en passant square if the moved pawn can be captured
if ((int(to) ^ int(from)) == 16
&& (pawn_attacks_bb(us, to - pawn_push(us)) & pieces(them, PAWN)))
&& (attacks_bb<PAWN>(to - pawn_push(us), us) & pieces(them, PAWN)))
{
st->epSquare = to - pawn_push(us);
k ^= Zobrist::enpassant[file_of(st->epSquare)];