Fix sometimes incorrect key for prefetches

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index ba015d3c38edb3cf87be062f952f4fbcec568cc4..ae1da017770cd34ea79eabfc961a27359eb0ad61 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -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;
@@ -1080,8 +1080,9 @@ bool Position::see_ge(Move m, Value threshold) const {
   if (swap <= 0)
       return true;
 
+  assert(color_of(piece_on(from)) == sideToMove);
   Bitboard occupied = pieces() ^ from ^ to;
-  Color stm = color_of(piece_on(from));
+  Color stm = sideToMove;
   Bitboard attackers = attackers_to(to, occupied);
   Bitboard stmAttackers, bb;
   int res = 1;