Introduce a function to compute NNUE accumulator

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 6ca2cfa5adb9c562398f14db127aaed7529ee47e..5cb9750c3235a72d6c33fc99943c379c85ac4380 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -730,10 +730,10 @@ namespace {
         goto moves_loop;
     }
     else if (excludedMove) {
-        // excludeMove implies that we had a ttHit on the containing non-excluded search with ss->staticEval filled from TT
-        // However static evals from the TT aren't good enough (-13 elo), presumably due to changing optimism context
-        // Recalculate value with current optimism (without updating thread avgComplexity)
-        ss->staticEval = eval = evaluate(pos, &complexity);
+        // Providing the hint that this node's accumulator will be used often brings significant Elo gain (13 elo)
+        Eval::NNUE::hint_common_parent_position(pos);
+        eval = ss->staticEval;
+        complexity = abs(ss->staticEval - pos.psq_eg_stm());
     }
     else if (ss->ttHit)
     {