From: mstembera <MissingEmail@email>
Date: Tue, 15 Sep 2015 20:28:42 +0000 (-0700)
Subject: Reduce writes in TT::probe().
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=68fbb1e0522056e0ab8062fe68c26b3af5cffed3;hp=01fab4d432b50f95f9def1b757d854fd0c385224

Reduce writes in TT::probe().

Only refresh TT entry when it's really necessary.
This should give a small speed boost for some machines.
And it's a risk-free change.

No functional change.

Resolves #429
---

diff --git a/src/tt.cpp b/src/tt.cpp
index f9674601..0c77d6b2 100644
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -78,7 +78,7 @@ TTEntry* TranspositionTable::probe(const Key key, bool& found) const {
   for (int i = 0; i < ClusterSize; ++i)
       if (!tte[i].key16 || tte[i].key16 == key16)
       {
-          if (tte[i].key16)
+          if ((tte[i].genBound8 & 0xFC) != generation8 && tte[i].key16)
               tte[i].genBound8 = uint8_t(generation8 | tte[i].bound()); // Refresh
 
           return found = (bool)tte[i].key16, &tte[i];