Avoid unnecessary creation of accumulator cache

Saves a (currently) 800 KB allocation and deallocation when running
`eval`, not particularly significant and zero impact on play but not
necessary either.

closes #5201

No functional change

AUTHORS

@@ -46,6 +46,7 @@ Bryan Cross (crossbr)
 candirufish
 Chess13234
 Chris Cain (ceebo)
+Ciekce
 clefrks
 Clemens L. (rn5f107s2)
 Cody Ho (aesrentai)

src/evaluate.cpp

@@ -100,11 +100,11 @@ Value Eval::evaluate(const Eval::NNUE::Networks&    networks,
 // Trace scores are from white's point of view
 std::string Eval::trace(Position& pos, const Eval::NNUE::Networks& networks) {
 
-    auto caches = std::make_unique<Eval::NNUE::AccumulatorCaches>(networks);
-
     if (pos.checkers())
         return "Final evaluation: none (in check)";
 
+    auto caches = std::make_unique<Eval::NNUE::AccumulatorCaches>(networks);
+
     std::stringstream ss;
     ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2);
     ss << '\n' << NNUE::trace(pos, networks, *caches) << '\n';