Fix sometimes incorrect key for prefetches
authormstembera <MissingEmail@email>
Sat, 23 Oct 2021 03:01:05 +0000 (20:01 -0700)
committerStéphane Nicolet <cassio@free.fr>
Mon, 25 Oct 2021 10:26:44 +0000 (12:26 +0200)
STC
https://tests.stockfishchess.org/tests/view/61737b4f6ce927be32558401
LLR: 2.95 (-2.94,2.94) <-2.50,0.50>
Total: 138712 W: 34914 L: 34942 D: 68856
Ptnml(0-2): 421, 14817, 38894, 14817, 407

Very minor tweak since Position::key() depends on the 50 move rule counter.
Comments: https://github.com/mstembera/Stockfish/commit/cddde31eed505cdf0c4fc8ff96b89f6e39c797e1

closes https://github.com/official-stockfish/Stockfish/pull/3759

No functional change

src/position.cpp

index 0686d245bc77fe956f3a8e15a7f86360e610c38d..ae1da017770cd34ea79eabfc961a27359eb0ad61 100644 (file)
@@ -1013,9 +1013,9 @@ void Position::do_null_move(StateInfo& newSt) {
   }
 
   st->key ^= Zobrist::side;
+  ++st->rule50;
   prefetch(TT.first_entry(key()));
 
-  ++st->rule50;
   st->pliesFromNull = 0;
 
   sideToMove = ~sideToMove;