/// the least valuable of the four entries in a cluster. A TTEntry t1 is
/// considered to be more valuable than a TTEntry t2 if t1 is from the
/// current search and t2 is from a previous search, or if the depth of t1
-/// is bigger than the depth of t2.
+/// is bigger than the depth of t2. A TTEntry of type VALUE_TYPE_EVAL
+/// never replaces another entry for the same position.
-TTEntry* TranspositionTable::store(const Position &pos, Value v, Depth d,
+void TranspositionTable::store(const Position &pos, Value v, Depth d,
Move m, ValueType type) {
TTEntry *tte, *replace;
{
if (!tte->key() || tte->key() == pos.get_key()) // empty or overwrite old
{
+ // Do not overwrite position entry when VALUE_TYPE_EVAL
+ if ( tte->key()
+ && type == VALUE_TYPE_EVAL)
+ return;
+
if (m == MOVE_NONE)
m = tte->move();
*tte = TTEntry(pos.get_key(), v, type, d, m, generation);
- return tte;
+ return;
}
else if (i == 0) // replace would be a no-op in this common case
continue;
}
*replace = TTEntry(pos.get_key(), v, type, d, m, generation);
writes++;
- return replace;
}