Don't read eval from TT anymore

Rely fully on eval cache. Note that we still save eval
info to TT, this is not needed at this moment and will be
removed in future patches. We keep it so to have a "non
functional change" patch.

No functional change.

diff --git a/src/search.cpp b/src/search.cpp
index b538897944ba7d174e17fdded262d8ddb719f0f4..79046ad2007aedbc13ab8315b1805adc65a67ef9 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -574,31 +574,21 @@ namespace {
     // Step 5. Evaluate the position statically and update parent's gain statistics
     if (inCheck)
         ss->staticEval = ss->evalMargin = eval = VALUE_NONE;
-
-    else if (tte)
+    else
     {
-        // Following asserts are valid only in single thread condition because
-        // TT access is always racy and its contents cannot be trusted.
-        assert(tte->static_value() != VALUE_NONE || Threads.size() > 1);
-        assert(ttValue != VALUE_NONE || tte->type() == BOUND_NONE || Threads.size() > 1);
-
-        ss->staticEval = eval = tte->static_value();
-        ss->evalMargin = tte->static_value_margin();
-
-        if (eval == VALUE_NONE || ss->evalMargin == VALUE_NONE) // Due to a race
-            eval = ss->staticEval = evaluate(pos, ss->evalMargin);
+        eval = ss->staticEval = evaluate(pos, ss->evalMargin);
 
         // Can ttValue be used as a better position evaluation?
-        if (ttValue != VALUE_NONE)
+        if (tte && ttValue != VALUE_NONE)
+        {
             if (   ((tte->type() & BOUND_LOWER) && ttValue > eval)
                 || ((tte->type() & BOUND_UPPER) && ttValue < eval))
                 eval = ttValue;
-    }
-    else
-    {
-        eval = ss->staticEval = evaluate(pos, ss->evalMargin);
-        TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE,
-                 ss->staticEval, ss->evalMargin);
+        }
+
+        if (!tte)
+            TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE,
+                     ss->staticEval, ss->evalMargin);
     }
 
     // Update gain for the parent non-capture move given the static position
@@ -1151,18 +1141,7 @@ split_point_start: // At split points actual search starts from here
     }
     else
     {
-        if (tte)
-        {
-            assert(tte->static_value() != VALUE_NONE || Threads.size() > 1);
-
-            ss->staticEval = bestValue = tte->static_value();
-            ss->evalMargin = tte->static_value_margin();
-
-            if (ss->staticEval == VALUE_NONE || ss->evalMargin == VALUE_NONE) // Due to a race
-                ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
-        }
-        else
-            ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
+        ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
 
         // Stand pat. Return immediately if static value is at least beta
         if (bestValue >= beta)