if (isCheck)
staticValue = -VALUE_INFINITE;
- else if (tte && tte->type() == VALUE_TYPE_EVAL)
+ else if (tte && (tte->type() == VALUE_TYPE_EVAL || tte->staticValue()))
{
// Use the cached evaluation score if possible
assert(tte->value() == evaluate(pos, ei, threadID));
if (!pvNode)
{
Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1));
+ Value v = value_to_tt(bestValue, ply);
+ TTEntry* e;
if (bestValue < beta)
- TT.store(pos, value_to_tt(bestValue, ply), d, MOVE_NONE, VALUE_TYPE_UPPER);
+ e = TT.store(pos, v, d, MOVE_NONE, VALUE_TYPE_UPPER);
else
- TT.store(pos, value_to_tt(bestValue, ply), d, MOVE_NONE, VALUE_TYPE_LOWER);
+ e = TT.store(pos, v, d, MOVE_NONE, VALUE_TYPE_LOWER);
+
+ assert(e && e == TT.retrieve(pos));
+ assert(!e->staticValue());
+
+ // If the just stored value happens to be equal to the static evaluation
+ // score then set the flag, so to avoid calling evaluation() next time we
+ // hit this position.
+ if (staticValue == v && !ei.futilityMargin)
+ e->setStaticValue();
}
// Update killers only for good check moves
/// current search and t2 is from a previous search, or if the depth of t1
/// is bigger than the depth of t2.
-void TranspositionTable::store(const Position &pos, Value v, Depth d,
+TTEntry* TranspositionTable::store(const Position &pos, Value v, Depth d,
Move m, ValueType type) {
TTEntry *tte, *replace;
m = tte->move();
*tte = TTEntry(pos.get_key(), v, type, d, m, generation);
- return;
+ return tte;
}
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;
}
/// the 32 bits of the data field are so defined
///
/// bit 0-16: move
-/// bit 17-19: not used
+/// bit 17: stored value equals static value
+/// bit 18-19: not used
/// bit 20-22: value type
/// bit 23-31: generation
Value value() const { return Value(value_); }
ValueType type() const { return ValueType((data >> 20) & 7); }
int generation() const { return (data >> 23); }
+ bool staticValue() const { return ((data >> 17) & 1); }
+ void setStaticValue() { data |= (1 << 17); }
private:
Key key_;
~TranspositionTable();
void set_size(unsigned mbSize);
void clear();
- void store(const Position &pos, Value v, Depth d, Move m, ValueType type);
+ TTEntry* store(const Position &pos, Value v, Depth d, Move m, ValueType type);
TTEntry* retrieve(const Position &pos) const;
void new_search();
void insert_pv(const Position &pos, Move pv[]);