Correctly round evaluation to grain size

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 3c0be19d2aa0c75d9974b6a86dfe61491d94c0df..53afc447aed901b1d39df15f63e9461cadb3cc83 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -1105,7 +1105,7 @@ namespace {
     Value ev = Value((eg * int(sf)) / SCALE_FACTOR_NORMAL);
 
     int result = (mg_value(v) * int(ph) + ev * int(128 - ph)) / 128;
-    return Value(result & ~(GrainSize - 1));
+    return Value((result + GrainSize / 2) & ~(GrainSize - 1));
   }