HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-24 02:57:11 +08:00
Code Issues Packages Projects Releases Wiki Activity

Greatly speed up SEE

Browse Source 
Simply reshuffling the code inverting the condition in next_attacker()
yields a miraculous speed up of more than 3% under gcc!

On my laptop a bench run goes from 320Knps to 330Knps

No functional change.
This commit is contained in:
Marco Costalba
2012-09-02 00:15:27 +02:00
parent 9cdca7516c
commit e6d8e74152
1 changed files with 17 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
src/position.cpp
View File

@@ -106,25 +106,24 @@ void init() {
/// valuable attacker for the side to move, remove the attacker we just found
/// from the 'occupied' bitboard and scan for new X-ray attacks behind it.
template<PieceType Pt> static FORCE_INLINE
template<int Pt> static FORCE_INLINE
PieceType next_attacker(const Bitboard* bb, const Square& to, const Bitboard& stmAttackers,
Bitboard& occupied, Bitboard& attackers) {
const PieceType NextPt = PieceType((int)Pt + 1);
if (stmAttackers & bb[Pt])
{
Bitboard b = stmAttackers & bb[Pt];
occupied ^= b & ~(b - 1);
if (!(stmAttackers & bb[Pt]))
return next_attacker<NextPt>(bb, to, stmAttackers, occupied, attackers);
if (Pt == PAWN || Pt == BISHOP || Pt == QUEEN)
attackers |= attacks_bb<BISHOP>(to, occupied) & (bb[BISHOP] | bb[QUEEN]);
Bitboard b = stmAttackers & bb[Pt];
occupied ^= b & ~(b - 1);
if (Pt == ROOK || Pt == QUEEN)
attackers |= attacks_bb<ROOK>(to, occupied) & (bb[ROOK] | bb[QUEEN]);
if (Pt == PAWN || Pt == BISHOP || Pt == QUEEN)
attackers |= attacks_bb<BISHOP>(to, occupied) & (bb[BISHOP] | bb[QUEEN]);
if (Pt == ROOK || Pt == QUEEN)
attackers |= attacks_bb<ROOK>(to, occupied) & (bb[ROOK] | bb[QUEEN]);
return Pt;
return (PieceType)Pt;
}
return next_attacker<Pt+1>(bb, to, stmAttackers, occupied, attackers);
}
template<> FORCE_INLINE
@@ -1312,11 +1311,12 @@ int Position::see(Move m) const {
stm = ~stm;
stmAttackers = attackers & pieces(stm);
// Stop before processing a king capture
if (captured == KING && stmAttackers)
if (captured == KING)
{
assert(slIndex < 32);
swapList[slIndex++] = QueenValueMg * 16;
// Stop before processing a king capture
if (stmAttackers)
swapList[slIndex++] = QueenValueMg * 16;
break;
}