fix missing condition

anematode · vondele · commit c109a88ebe93 · 2025-12-03T12:32:29.000+01:00
Fixes a bug in #6453 abd835d The modifications to the DirtyThreats bitboards should only happen if PutPiece is true. This somehow didn't affect bench at the default parameters. Reference AVX2: ./stockfish.killdeer-fix.avx2 bench 64 1 23 Nodes searched : 178140156 Nodes/second : 1503152 before patch: ./stockfish.master.avx512icl bench 64 1 23 Nodes searched : 218349728 Nodes/second : 1743450 after patch: ./stockfish.killdeer-fix.avx512icl bench 64 1 23 Nodes searched : 178140156 Nodes/second : 1727520 passed STC: LLR: 2.95 (-2.94,2.94) <-1.75,0.25> Total: 39328 W: 10293 L: 10080 D: 18955 Ptnml(0-2): 113, 4306, 10629, 4487, 129 https://tests.stockfishchess.org/tests/view/692fb2d8b23dfeae38d01c81 closes #6463 Bench: 2912398
diff --git a/src/position.cpp b/src/position.cpp
@@ -1159,8 +1159,11 @@ void Position::update_piece_threats(Piece               pc,
     if (!all_attackers)
         return;  // Square s is threatened iff there's at least one attacker
 
-    dts->threatenedSqs |= square_bb(s);
-    dts->threateningSqs |= all_attackers;
+    if constexpr (PutPiece)
+    {
+        dts->threatenedSqs |= square_bb(s);
+        dts->threateningSqs |= all_attackers;
+    }
 
     DirtyThreat dt_template{NO_PIECE, pc, Square(0), s, PutPiece};
     write_multiple_dirties<DirtyThreat::PcSqOffset, DirtyThreat::PcOffset>(*this, all_attackers,
