inline Value razor_margin(Depth d) { return Value(512 + 32 * d); }
// Futility lookup tables (initialized at startup) and their access functions
inline Value razor_margin(Depth d) { return Value(512 + 32 * d); }
// Futility lookup tables (initialized at startup) and their access functions
Value value_to_tt(Value v, int ply);
Value value_from_tt(Value v, int ply);
void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt);
Value value_to_tt(Value v, int ply);
Value value_from_tt(Value v, int ply);
void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt);
- string uci_pv(const Position& pos, int depth, Value alpha, Value beta);
+ string uci_pv(const Position& pos, Depth depth, Value alpha, Value beta);
- 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;
+ }
{
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));
{
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));
void id_loop(Position& pos) {
Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
void id_loop(Position& pos) {
Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
Value bestValue, alpha, beta, delta;
std::memset(ss-2, 0, 5 * sizeof(Stack));
Value bestValue, alpha, beta, delta;
std::memset(ss-2, 0, 5 * sizeof(Stack));
for (PVIdx = 0; PVIdx < std::min(multiPV, RootMoves.size()) && !Signals.stop; ++PVIdx)
{
// Reset aspiration window starting size
for (PVIdx = 0; PVIdx < std::min(multiPV, RootMoves.size()) && !Signals.stop; ++PVIdx)
{
// Reset aspiration window starting size
- bestValue = search<Root, false>(pos, ss, alpha, beta, depth * ONE_PLY, false);
+ bestValue = search<Root, false>(pos, ss, alpha, beta, depth, false);
// Bring the best move to the front. It is critical that sorting
// is done with a stable algorithm because all the values but the
// Bring the best move to the front. It is critical that sorting
// is done with a stable algorithm because all the values but the
alpha = std::max(bestValue - delta, -VALUE_INFINITE);
Signals.failedLowAtRoot = true;
Signals.stopOnPonderhit = false;
}
else if (bestValue >= beta)
alpha = std::max(bestValue - delta, -VALUE_INFINITE);
Signals.failedLowAtRoot = true;
Signals.stopOnPonderhit = false;
}
else if (bestValue >= beta)
if (Limits.use_time_management() && !Signals.stop && !Signals.stopOnPonderhit)
{
// Take some extra time if the best move has changed
if (Limits.use_time_management() && !Signals.stop && !Signals.stopOnPonderhit)
{
// Take some extra time if the best move has changed
TimeMgr.pv_instability(BestMoveChanges);
// Stop the search if only one legal move is available or all
TimeMgr.pv_instability(BestMoveChanges);
// Stop the search if only one legal move is available or all
Move ttMove, move, excludedMove, bestMove;
Depth ext, newDepth, predictedDepth;
Value bestValue, value, ttValue, eval, nullValue, futilityValue;
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;
bool captureOrPromotion, dangerous, doFullDepthSearch;
int moveCount, quietCount;
// Step 15. Reduced depth search (LMR). If the move fails high it will be
// re-searched at full depth.
if ( depth >= 3 * ONE_PLY
// Step 15. Reduced depth search (LMR). If the move fails high it will be
// re-searched at full depth.
if ( depth >= 3 * ONE_PLY
// 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.
// 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.
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)
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 ?
RootMove& rm = *std::find(RootMoves.begin(), RootMoves.end(), move);
// PV move or new best move ?
// 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.
// 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.
- string uci_pv(const Position& pos, int depth, Value alpha, Value beta) {
+ string uci_pv(const Position& pos, Depth depth, Value alpha, Value beta) {
Value v = updated ? RootMoves[i].score : RootMoves[i].prevScore;
if (ss.rdbuf()->in_avail()) // Not at first line
ss << "\n";
Value v = updated ? RootMoves[i].score : RootMoves[i].prevScore;
if (ss.rdbuf()->in_avail()) // Not at first line
ss << "\n";
<< " seldepth " << selDepth
<< " multipv " << i + 1
<< " score " << (i == PVIdx ? UCI::format_value(v, alpha, beta) : UCI::format_value(v))
<< " seldepth " << selDepth
<< " multipv " << i + 1
<< " score " << (i == PVIdx ? UCI::format_value(v, alpha, beta) : UCI::format_value(v))
// Loop across all split points and sum accumulated SplitPoint nodes plus
// all the currently active positions nodes.
// Loop across all split points and sum accumulated SplitPoint nodes plus
// all the currently active positions nodes.