Key posKey;
Move ttMove, move, excludedMove, bestMove, threatMove;
Depth ext, newDepth;
- Value bestValue, value, ttValue;
+ Value bestValue, value, ttValue, ttValueUpper;
Value eval, nullValue, futilityValue;
bool inCheck, givesCheck, pvMove, singularExtensionNode;
bool captureOrPromotion, dangerous, doFullDepthSearch;
tte = TT.probe(posKey);
ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE;
ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
+ ttValueUpper = tte ? value_from_tt(tte->value_upper(), ss->ply) : VALUE_NONE;
// At PV nodes we check for exact scores, while at non-PV nodes we check for
// a fail high/low. Biggest advantage at probing at PV nodes is to have a
// smooth experience in analysis mode. We don't probe at Root nodes otherwise
// we should also update RootMoveList to avoid bogus output.
- if ( !RootNode
- && tte
- && tte->depth() >= depth
- && ttValue != VALUE_NONE // Only in case of TT access race
- && ( PvNode ? tte->type() == BOUND_EXACT
- : ttValue >= beta ? (tte->type() & BOUND_LOWER)
- : (tte->type() & BOUND_UPPER)))
+ if (!RootNode && tte)
{
- TT.refresh(tte);
- ss->currentMove = ttMove; // Can be MOVE_NONE
+ // Fail High
+ if ( (tte->type() & BOUND_LOWER)
+ && ttValue >= beta
+ && tte->depth() >= depth
+ && ttValue != VALUE_NONE) // Only in case of TT access race
+ {
+ // Update killers, we assume ttMove caused a cut-off
+ if ( ttMove
+ && !pos.is_capture_or_promotion(ttMove)
+ && ttMove != ss->killers[0])
+ {
+ ss->killers[1] = ss->killers[0];
+ ss->killers[0] = ttMove;
+ }
+ TT.refresh(tte);
+ ss->currentMove = ttMove; // Can be MOVE_NONE
+ return ttValue;
+ }
- if ( ttValue >= beta
- && ttMove
- && !pos.is_capture_or_promotion(ttMove)
- && ttMove != ss->killers[0])
+ // Fail Low
+ if ( (tte->type() & BOUND_UPPER)
+ && ttValueUpper < beta
+ && tte->depth_upper() >= depth
+ && ttValueUpper != VALUE_NONE) // Only in case of TT access race
{
- ss->killers[1] = ss->killers[0];
- ss->killers[0] = ttMove;
+ TT.refresh(tte);
+ ss->currentMove = ttMove; // Can be MOVE_NONE
+ return ttValueUpper;
}
- return ttValue;
}
// Step 5. Evaluate the position statically and update parent's gain statistics
const TTEntry* tte;
Key posKey;
Move ttMove, move, bestMove;
- Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
+ Value bestValue, value, ttValue, ttValueUpper, futilityValue, futilityBase, oldAlpha;
bool givesCheck, enoughMaterial, evasionPrunable, fromNull;
Depth ttDepth;
tte = TT.probe(posKey);
ttMove = tte ? tte->move() : MOVE_NONE;
ttValue = tte ? value_from_tt(tte->value(),ss->ply) : VALUE_NONE;
+ ttValueUpper = tte ? value_from_tt(tte->value_upper(),ss->ply) : VALUE_NONE;
// Decide whether or not to include checks, this fixes also the type of
// TT entry depth that we are going to use. Note that in qsearch we use
// only two types of depth in TT: DEPTH_QS_CHECKS or DEPTH_QS_NO_CHECKS.
ttDepth = InCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS
: DEPTH_QS_NO_CHECKS;
- if ( tte
- && tte->depth() >= ttDepth
- && ttValue != VALUE_NONE // Only in case of TT access race
- && ( PvNode ? tte->type() == BOUND_EXACT
- : ttValue >= beta ? (tte->type() & BOUND_LOWER)
- : (tte->type() & BOUND_UPPER)))
+ if (tte)
{
- ss->currentMove = ttMove; // Can be MOVE_NONE
- return ttValue;
+ // Fail High
+ if ( (tte->type() & BOUND_LOWER)
+ && ttValue >= beta
+ && tte->depth() >= ttDepth
+ && ttValue != VALUE_NONE) // Only in case of TT access race
+ {
+ ss->currentMove = ttMove; // Can be MOVE_NONE
+ return ttValue;
+ }
+
+ // Fail Low
+ if ( (tte->type() & BOUND_UPPER)
+ && ttValueUpper < beta
+ && tte->depth_upper() >= ttDepth
+ && ttValueUpper != VALUE_NONE) // Only in case of TT access race
+ {
+ ss->currentMove = ttMove; // Can be MOVE_NONE
+ return ttValueUpper;
+ }
}
// Evaluate the position statically
/// 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.
-void TranspositionTable::store(const Key posKey, Value v, Bound t, Depth d, Move m) {
+void TranspositionTable::store(const Key posKey, Value v, Bound b, Depth d, Move m) {
int c1, c2, c3;
TTEntry *tte, *replace;
for (int i = 0; i < ClusterSize; i++, tte++)
{
- if (!tte->key() || tte->key() == posKey32) // Empty or overwrite old
+ if (!tte->key())
+ tte->save(posKey32, v, b, d, m, generation);
+
+ if (tte->key() == posKey32)
{
// Preserve any existing ttMove
if (m == MOVE_NONE)
m = tte->move();
- tte->save(posKey32, v, t, d, m, generation);
+ tte->update(v, b, d, m, generation);
return;
}
if (c1 + c2 + c3 > 0)
replace = tte;
}
- replace->save(posKey32, v, t, d, m, generation);
+ replace->save(posKey32, v, b, d, m, generation);
}
public:
void save(uint32_t k, Value v, Bound b, Depth d, Move m, int g) {
- key32 = (uint32_t)k;
- move16 = (uint16_t)m;
- bound = (uint8_t)b;
- generation8 = (uint8_t)g;
- value16 = (int16_t)v;
- depth16 = (int16_t)d;
+ key32 = (uint32_t)k;
+ move16 = (uint16_t)m;
+ bound = (uint8_t)b;
+ generation8 = (uint8_t)g;
+ valueUpper = (int16_t)(b & BOUND_UPPER ? v : VALUE_NONE);
+ depthUpper = (int16_t)(b & BOUND_UPPER ? d : DEPTH_NONE);
+ valueLower = (int16_t)(b & BOUND_LOWER ? v : VALUE_NONE);
+ depthLower = (int16_t)(b & BOUND_LOWER ? d : DEPTH_NONE);
}
+
+ void update(Value v, Bound b, Depth d, Move m, int g) {
+
+ move16 = (uint16_t)m;
+ bound |= (uint8_t)b;
+ generation8 = (uint8_t)g;
+
+ if (b & BOUND_UPPER)
+ {
+ valueUpper = (int16_t)v;
+ depthUpper = (int16_t)d;
+ }
+
+ if (b & BOUND_LOWER)
+ {
+ valueLower = (int16_t)v;
+ depthLower = (int16_t)d;
+ }
+ }
+
void set_generation(int g) { generation8 = (uint8_t)g; }
uint32_t key() const { return key32; }
- Depth depth() const { return (Depth)depth16; }
+ Depth depth() const { return (Depth)depthLower; }
+ Depth depth_upper() const { return (Depth)depthUpper; }
Move move() const { return (Move)move16; }
- Value value() const { return (Value)value16; }
+ Value value() const { return (Value)valueLower; }
+ Value value_upper() const { return (Value)valueUpper; }
Bound type() const { return (Bound)bound; }
int generation() const { return (int)generation8; }
uint32_t key32;
uint16_t move16;
uint8_t bound, generation8;
- int16_t value16, depth16;
+ int16_t valueLower, depthLower, valueUpper, depthUpper;
};
~TranspositionTable();
void set_size(size_t mbSize);
void clear();
- void store(const Key posKey, Value v, Bound type, Depth d, Move m);
+ void store(const Key posKey, Value v, Bound b, Depth d, Move m);
TTEntry* probe(const Key posKey) const;
void new_search();
TTEntry* first_entry(const Key posKey) const;