Introduce single_bit() helper

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 83a0c9123c708b2e739ecb9a737f51fa2ab1fa9d..79fe1ae37ad5105427b88b85d9c7bff8ac63f5a9 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -517,7 +517,7 @@ namespace {
 
             assert(b);
 
-            if (!(b & (b - 1)) && (b & pos.pieces(Them)))
+            if (single_bit(b) && (b & pos.pieces(Them)))
                 score += ThreatBonus[Piece][type_of(pos.piece_on(first_1(b)))] / 2;
         }