inline Value razor_margin(Depth d) { return Value(512 + 32 * d); }
// Futility lookup tables (initialized at startup) and their access functions
- int FutilityMoveCounts[2][32]; // [improving][depth]
+ int FutilityMoveCounts[2][16]; // [improving][depth]
inline Value futility_margin(Depth d) {
return Value(200 * d);
void Search::init() {
- int d; // depth (ONE_PLY == 2)
- int hd; // half depth (ONE_PLY == 1)
- int mc; // moveCount
-
// Init reductions array
- for (hd = 1; hd < 64; ++hd) for (mc = 1; mc < 64; ++mc)
- {
- double pvRed = 0.00 + log(double(hd)) * log(double(mc)) / 3.00;
- double nonPVRed = 0.33 + log(double(hd)) * log(double(mc)) / 2.25;
+ for (int d = 1; d < 64; ++d)
+ for (int mc = 1; mc < 64; ++mc)
+ {
+ double pvRed = 0.00 + log(double(d)) * log(double(mc)) / 3.00;
+ double nonPVRed = 0.33 + log(double(d)) * log(double(mc)) / 2.25;
- Reductions[1][1][hd][mc] = int8_t( pvRed >= 1.0 ? pvRed + 0.5: 0);
- Reductions[0][1][hd][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed + 0.5: 0);
+ Reductions[1][1][d][mc] = int8_t( pvRed >= 1.0 ? pvRed + 0.5: 0);
+ Reductions[0][1][d][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed + 0.5: 0);
- Reductions[1][0][hd][mc] = Reductions[1][1][hd][mc];
- Reductions[0][0][hd][mc] = Reductions[0][1][hd][mc];
+ Reductions[1][0][d][mc] = Reductions[1][1][d][mc];
+ Reductions[0][0][d][mc] = Reductions[0][1][d][mc];
- if (Reductions[0][0][hd][mc] >= 2)
- Reductions[0][0][hd][mc] += 1;
- }
+ // Increase reduction when eval is not improving
+ if (Reductions[0][0][d][mc] >= 2)
+ Reductions[0][0][d][mc] += 1;
+ }
// Init futility move count array
- for (d = 0; d < 32; ++d)
+ for (int d = 0; d < 16; ++d)
{
FutilityMoveCounts[0][d] = int(2.4 + 0.773 * pow(d + 0.00, 1.8));
FutilityMoveCounts[1][d] = int(2.9 + 1.045 * pow(d + 0.49, 1.8));
// re-search, otherwise exit the loop.
if (bestValue <= alpha)
{
+ beta = (alpha + beta) / 2;
alpha = std::max(bestValue - delta, -VALUE_INFINITE);
Signals.failedLowAtRoot = true;
Signals.stopOnPonderhit = false;
}
else if (bestValue >= beta)
+ {
+ alpha = (alpha + beta) / 2;
beta = std::min(bestValue + delta, VALUE_INFINITE);
-
+ }
else
break;
- delta += 3 * delta / 8;
+ delta += delta / 2;
assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
}
Move ttMove, move, excludedMove, bestMove;
Depth ext, newDepth, predictedDepth;
Value bestValue, value, ttValue, eval, nullValue, futilityValue;
- bool inCheck, givesCheck, pvMove, singularExtensionNode, improving;
+ bool inCheck, givesCheck, singularExtensionNode, improving;
bool captureOrPromotion, dangerous, doFullDepthSearch;
int moveCount, quietCount;
&& !captureOrPromotion
&& !inCheck
&& !dangerous
- /* && move != ttMove Already implicit in the next condition */
&& bestValue > VALUE_MATED_IN_MAX_PLY)
{
// Move count based pruning
continue;
}
- pvMove = PvNode && moveCount == 1;
ss->currentMove = move;
if (!SpNode && !captureOrPromotion && quietCount < 64)
quietsSearched[quietCount++] = move;
// Step 15. Reduced depth search (LMR). If the move fails high it will be
// re-searched at full depth.
if ( depth >= 3 * ONE_PLY
- && !pvMove
+ && moveCount > 1
&& !captureOrPromotion
- && move != ttMove
&& move != ss->killers[0]
&& move != ss->killers[1])
{
ss->reduction = DEPTH_ZERO;
}
else
- doFullDepthSearch = !pvMove;
+ doFullDepthSearch = !PvNode || moveCount > 1;
// Step 16. Full depth search, when LMR is skipped or fails high
if (doFullDepthSearch)
// For PV nodes only, do a full PV search on the first move or after a fail
// high (in the latter case search only if value < beta), otherwise let the
// parent node fail low with value <= alpha and to try another move.
- if (PvNode && (pvMove || (value > alpha && (RootNode || value < beta))))
+ if (PvNode && (moveCount == 1 || (value > alpha && (RootNode || value < beta))))
value = newDepth < ONE_PLY ?
givesCheck ? -qsearch<PV, true>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
: -qsearch<PV, false>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
RootMove& rm = *std::find(RootMoves.begin(), RootMoves.end(), move);
// PV move or new best move ?
- if (pvMove || value > alpha)
+ if (moveCount == 1 || value > alpha)
{
rm.score = value;
rm.extract_pv_from_tt(pos);
// We record how often the best move has been changed in each
// iteration. This information is used for time management: When
// the best move changes frequently, we allocate some more time.
- if (!pvMove)
+ if (moveCount > 1)
++BestMoveChanges;
}
else
if ( !PvNode
&& !InCheck
&& !givesCheck
- && move != ttMove
&& futilityBase > -VALUE_KNOWN_WIN
&& !pos.advanced_pawn_push(move))
{
// Don't search moves with negative SEE values
if ( !PvNode
&& (!InCheck || evasionPrunable)
- && move != ttMove
&& type_of(move) != PROMOTION
&& pos.see_sign(move) < VALUE_ZERO)
continue;
void check_time() {
static Time::point lastInfoTime = Time::now();
- int64_t nodes = 0; // Workaround silly 'uninitialized' gcc warning
+ Time::point elapsed = Time::now() - SearchTime;
if (Time::now() - lastInfoTime >= 1000)
{
dbg_print();
}
- if (Limits.ponder)
- return;
+ if (Limits.use_time_management() && !Limits.ponder)
+ {
+ bool stillAtFirstMove = Signals.firstRootMove
+ && !Signals.failedLowAtRoot
+ && elapsed > TimeMgr.available_time() * 75 / 100;
- if (Limits.nodes)
+ if ( stillAtFirstMove
+ || elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution)
+ Signals.stop = true;
+ }
+ else if (Limits.movetime && elapsed >= Limits.movetime)
+ Signals.stop = true;
+
+ else if (Limits.nodes)
{
Threads.mutex.lock();
- nodes = RootPos.nodes_searched();
+ int64_t nodes = RootPos.nodes_searched();
// Loop across all split points and sum accumulated SplitPoint nodes plus
// all the currently active positions nodes.
}
Threads.mutex.unlock();
- }
- Time::point elapsed = Time::now() - SearchTime;
- bool stillAtFirstMove = Signals.firstRootMove
- && !Signals.failedLowAtRoot
- && elapsed > TimeMgr.available_time() * 75 / 100;
-
- bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution
- || stillAtFirstMove;
-
- if ( (Limits.use_time_management() && noMoreTime)
- || (Limits.movetime && elapsed >= Limits.movetime)
- || (Limits.nodes && nodes >= Limits.nodes))
- Signals.stop = true;
+ if (nodes >= Limits.nodes)
+ Signals.stop = true;
+ }
}
projects / stockfish / blobdiff