Removes an 8 year old micro optimization aimed at 32-bit architectures
because back then doing an xor of a Key could not be done in one instruction.
See original commit here
821e1c7
STC https://tests.stockfishchess.org/tests/view/
5ef5833dde213bf647527d0c
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 162648 W: 31053 L: 31097 D: 100498
Ptnml(0-2): 2841, 18966, 37715, 19000, 2802
LTC https://tests.stockfishchess.org/tests/view/
5ef7b1bbf993893290cc1489
LLR: 2.93 (-2.94,2.94) {-1.50,0.50}
Total: 62360 W: 7617 L: 7586 D: 47157
Ptnml(0-2): 423, 5662, 18994, 5663, 438
closes https://github.com/official-stockfish/Stockfish/pull/2775
bench:
4591425
Zobrist::enpassant[f] = rng.rand<Key>();
for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr)
- {
- Zobrist::castling[cr] = 0;
- Bitboard b = cr;
- while (b)
- {
- Key k = Zobrist::castling[1ULL << pop_lsb(&b)];
- Zobrist::castling[cr] ^= k ? k : rng.rand<Key>();
- }
- }
+ Zobrist::castling[cr] = rng.rand<Key>();
Zobrist::side = rng.rand<Key>();
Zobrist::noPawns = rng.rand<Key>();
// Update castling rights if needed
if (st->castlingRights && (castlingRightsMask[from] | castlingRightsMask[to]))
{
- int cr = castlingRightsMask[from] | castlingRightsMask[to];
- k ^= Zobrist::castling[st->castlingRights & cr];
- st->castlingRights &= ~cr;
+ k ^= Zobrist::castling[st->castlingRights];
+ st->castlingRights &= ~(castlingRightsMask[from] | castlingRightsMask[to]);
+ k ^= Zobrist::castling[st->castlingRights];
}
// Move the piece. The tricky Chess960 castling is handled earlier