const bool FakeSplit = false;
// Different node types, used as template parameter
- enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV };
+ enum NodeType { Root, PV, NonPV };
// Dynamic razoring margin based on depth
- inline Value razor_margin(Depth d) { return Value(512 + 16 * int(d)); }
+ inline Value razor_margin(Depth d) { return Value(512 + 16 * d); }
// Futility lookup tables (initialized at startup) and their access functions
int FutilityMoveCounts[2][32]; // [improving][depth]
inline Value futility_margin(Depth d) {
- return Value(100 * int(d));
+ return Value(100 * d);
}
// Reduction lookup tables (initialized at startup) and their access function
GainsStats Gains;
MovesStats Countermoves, Followupmoves;
- template <NodeType NT>
+ template <NodeType NT, bool SpNode>
Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode);
template <NodeType NT, bool InCheck>
{
double pvRed = 0.00 + log(double(hd)) * log(double(mc)) / 3.00;
double nonPVRed = 0.33 + log(double(hd)) * log(double(mc)) / 2.25;
- Reductions[1][1][hd][mc] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(ONE_PLY)) : 0);
- Reductions[0][1][hd][mc] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(ONE_PLY)) : 0);
+ Reductions[1][1][hd][mc] = int8_t( pvRed >= 1.0 ? pvRed * int(ONE_PLY) : 0);
+ Reductions[0][1][hd][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed * int(ONE_PLY) : 0);
Reductions[1][0][hd][mc] = Reductions[1][1][hd][mc];
Reductions[0][0][hd][mc] = Reductions[0][1][hd][mc];
RootColor = RootPos.side_to_move();
TimeMgr.init(Limits, RootPos.game_ply(), RootColor);
- int cf = Options["Contempt Factor"] * PawnValueMg / 100; // From centipawns
+ int cf = Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns
DrawValue[ RootColor] = VALUE_DRAW - Value(cf);
DrawValue[~RootColor] = VALUE_DRAW + Value(cf);
<< " time: " << Limits.time[RootColor]
<< " increment: " << Limits.inc[RootColor]
<< " moves to go: " << Limits.movestogo
- << std::endl;
+ << "\n" << std::endl;
}
// Reset the threads, still sleeping: will wake up at split time
// high/low anymore.
while (true)
{
- bestValue = search<Root>(pos, ss, alpha, beta, depth * ONE_PLY, false);
+ bestValue = search<Root, false>(pos, ss, alpha, beta, depth * ONE_PLY, 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
// repeat all this work again. We also don't need to store anything to the hash
// table here: This is taken care of after we return from the split point.
- template <NodeType NT>
+ template <NodeType NT, bool SpNode>
Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode) {
- const bool PvNode = (NT == PV || NT == Root || NT == SplitPointPV || NT == SplitPointRoot);
- const bool SpNode = (NT == SplitPointPV || NT == SplitPointNonPV || NT == SplitPointRoot);
- const bool RootNode = (NT == Root || NT == SplitPointRoot);
+ const bool RootNode = NT == Root;
+ const bool PvNode = NT == PV || NT == Root;
assert(-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE);
assert(PvNode || (alpha == beta - 1));
: ttValue >= beta ? (tte->bound() & BOUND_LOWER)
: (tte->bound() & BOUND_UPPER)))
{
- TT.refresh(tte);
ss->currentMove = ttMove; // Can be MOVE_NONE
// If ttMove is quiet, update killers, history, counter move and followup move on TT hit
pos.do_null_move(st);
(ss+1)->skipNullMove = true;
nullValue = depth-R < ONE_PLY ? -qsearch<NonPV, false>(pos, ss+1, -beta, -beta+1, DEPTH_ZERO)
- : - search<NonPV>(pos, ss+1, -beta, -beta+1, depth-R, !cutNode);
+ : - search<NonPV, false>(pos, ss+1, -beta, -beta+1, depth-R, !cutNode);
(ss+1)->skipNullMove = false;
pos.undo_null_move();
// Do verification search at high depths
ss->skipNullMove = true;
Value v = depth-R < ONE_PLY ? qsearch<NonPV, false>(pos, ss, beta-1, beta, DEPTH_ZERO)
- : search<NonPV>(pos, ss, beta-1, beta, depth-R, false);
+ : search<NonPV, false>(pos, ss, beta-1, beta, depth-R, false);
ss->skipNullMove = false;
if (v >= beta)
{
ss->currentMove = move;
pos.do_move(move, st, ci, pos.gives_check(move, ci));
- value = -search<NonPV>(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode);
+ value = -search<NonPV, false>(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode);
pos.undo_move(move);
if (value >= rbeta)
return value;
// Step 10. Internal iterative deepening (skipped when in check)
if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY)
&& !ttMove
- && (PvNode || ss->staticEval + Value(256) >= beta))
+ && (PvNode || ss->staticEval + 256 >= beta))
{
Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4);
ss->skipNullMove = true;
- search<PvNode ? PV : NonPV>(pos, ss, alpha, beta, d, true);
+ search<PvNode ? PV : NonPV, false>(pos, ss, alpha, beta, d, true);
ss->skipNullMove = false;
tte = TT.probe(posKey);
Value rBeta = ttValue - int(depth);
ss->excludedMove = move;
ss->skipNullMove = true;
- value = search<NonPV>(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode);
+ value = search<NonPV, false>(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode);
ss->skipNullMove = false;
ss->excludedMove = MOVE_NONE;
if (predictedDepth < 7 * ONE_PLY)
{
futilityValue = ss->staticEval + futility_margin(predictedDepth)
- + Value(128) + Gains[pos.moved_piece(move)][to_sq(move)];
+ + 128 + Gains[pos.moved_piece(move)][to_sq(move)];
if (futilityValue <= alpha)
{
if (SpNode)
alpha = splitPoint->alpha;
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, true);
+ value = -search<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, d, true);
// Research at intermediate depth if reduction is very high
if (value > alpha && ss->reduction >= 4 * ONE_PLY)
{
Depth d2 = std::max(newDepth - 2 * ONE_PLY, ONE_PLY);
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d2, true);
+ value = -search<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, d2, true);
}
doFullDepthSearch = (value > alpha && ss->reduction != DEPTH_ZERO);
value = newDepth < ONE_PLY ?
givesCheck ? -qsearch<NonPV, true>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
: -qsearch<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
- : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode);
+ : - search<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode);
}
// For PV nodes only, do a full PV search on the first move or after a fail
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)
- : - search<PV>(pos, ss+1, -beta, -alpha, newDepth, false);
+ : - search<PV, false>(pos, ss+1, -beta, -alpha, newDepth, false);
// Step 17. Undo move
pos.undo_move(move);
alpha = splitPoint->alpha;
}
- // Finished searching the move. If Signals.stop is true, the search
- // was aborted because the user interrupted the search or because we
- // ran out of time. In this case, the return value of the search cannot
- // be trusted, and we don't update the best move and/or PV.
+ // Finished searching the move. If a stop or a cutoff occurred, the return
+ // value of the search cannot be trusted, and we return immediately without
+ // updating best move, PV and TT.
if (Signals.stop || thisThread->cutoff_occurred())
- return value; // To avoid returning VALUE_INFINITE
+ return VALUE_ZERO;
if (RootNode)
{
&& Threads.available_slave(thisThread)
&& thisThread->splitPointsSize < MAX_SPLITPOINTS_PER_THREAD)
{
- assert(bestValue < beta);
+ assert(bestValue > -VALUE_INFINITE && bestValue < beta);
thisThread->split<FakeSplit>(pos, ss, alpha, beta, &bestValue, &bestMove,
depth, moveCount, &mp, NT, cutNode);
+
+ if (Signals.stop || thisThread->cutoff_occurred())
+ return VALUE_ZERO;
+
if (bestValue >= beta)
break;
}
if (SpNode)
return bestValue;
+ // Following condition would detect a stop or a cutoff set only after move
+ // loop has been completed. But in this case bestValue is valid because we
+ // have fully searched our subtree, and we can anyhow save the result in TT.
+ /*
+ if (Signals.stop || thisThread->cutoff_occurred())
+ return VALUE_DRAW;
+ */
+
// Step 20. Check for mate and stalemate
// All legal moves have been searched and if there are no legal moves, it
- // must be mate or stalemate. Note that we can have a false positive in
- // case of Signals.stop or thread.cutoff_occurred() are set, but this is
- // harmless because return value is discarded anyhow in the parent nodes.
- // If we are in a singular extension search then return a fail low score.
- // A split node has at least one move - the one tried before to be split.
+ // must be mate or stalemate. If we are in a singular extension search then
+ // return a fail low score.
if (!moveCount)
return excludedMove ? alpha
: inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()];
- // If we have pruned all the moves without searching return a fail-low score
- if (bestValue == -VALUE_INFINITE)
- bestValue = alpha;
-
TT.store(posKey, value_to_tt(bestValue, ss->ply),
bestValue >= beta ? BOUND_LOWER :
PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
template <NodeType NT, bool InCheck>
Value qsearch(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth) {
- const bool PvNode = (NT == PV);
+ const bool PvNode = NT == PV;
assert(NT == PV || NT == NonPV);
assert(InCheck == !!pos.checkers());
if (PvNode && bestValue > alpha)
alpha = bestValue;
- futilityBase = bestValue + Value(128);
+ futilityBase = bestValue + 128;
}
// Initialize a MovePicker object for the current position, and prepare
string uci_pv(const Position& pos, int depth, Value alpha, Value beta) {
- std::stringstream s;
+ std::stringstream ss;
Time::point elapsed = Time::now() - SearchTime + 1;
size_t uciPVSize = std::min((size_t)Options["MultiPV"], RootMoves.size());
int selDepth = 0;
int d = updated ? depth : depth - 1;
Value v = updated ? RootMoves[i].score : RootMoves[i].prevScore;
- if (s.rdbuf()->in_avail()) // Not at first line
- s << "\n";
+ if (ss.rdbuf()->in_avail()) // Not at first line
+ ss << "\n";
- s << "info depth " << d
- << " seldepth " << selDepth
- << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
- << " nodes " << pos.nodes_searched()
- << " nps " << pos.nodes_searched() * 1000 / elapsed
- << " time " << elapsed
- << " multipv " << i + 1
- << " pv";
+ ss << "info depth " << d
+ << " seldepth " << selDepth
+ << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
+ << " nodes " << pos.nodes_searched()
+ << " nps " << pos.nodes_searched() * 1000 / elapsed
+ << " time " << elapsed
+ << " multipv " << i + 1
+ << " pv";
for (size_t j = 0; RootMoves[i].pv[j] != MOVE_NONE; ++j)
- s << " " << move_to_uci(RootMoves[i].pv[j], pos.is_chess960());
+ ss << " " << move_to_uci(RootMoves[i].pv[j], pos.is_chess960());
}
- return s.str();
+ return ss.str();
}
} // namespace
mutex.lock();
// If we are master and all slaves have finished then exit idle_loop
- if (this_sp && !this_sp->slavesMask)
+ if (this_sp && this_sp->slavesMask.none())
{
mutex.unlock();
break;
activePosition = &pos;
- switch (sp->nodeType) {
- case Root:
- search<SplitPointRoot>(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
- break;
- case PV:
- search<SplitPointPV>(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
- break;
- case NonPV:
- search<SplitPointNonPV>(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
- break;
- default:
+ if (sp->nodeType == NonPV)
+ search<NonPV, true>(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
+
+ else if (sp->nodeType == PV)
+ search<PV, true>(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
+
+ else if (sp->nodeType == Root)
+ search<Root, true>(pos, ss, sp->alpha, sp->beta, sp->depth, sp->cutNode);
+
+ else
assert(false);
- }
assert(searching);
searching = false;
activePosition = NULL;
- sp->slavesMask &= ~(1ULL << idx);
+ sp->slavesMask.reset(idx);
sp->nodes += pos.nodes_searched();
// Wake up the master thread so to allow it to return from the idle
// loop in case we are the last slave of the split point.
if ( Threads.sleepWhileIdle
&& this != sp->masterThread
- && !sp->slavesMask)
+ && sp->slavesMask.none())
{
assert(!sp->masterThread->searching);
sp->masterThread->notify_one();
// If this thread is the master of a split point and all slaves have finished
// their work at this split point, return from the idle loop.
- if (this_sp && !this_sp->slavesMask)
+ if (this_sp && this_sp->slavesMask.none())
{
this_sp->mutex.lock();
- bool finished = !this_sp->slavesMask; // Retest under lock protection
+ bool finished = this_sp->slavesMask.none(); // Retest under lock protection
this_sp->mutex.unlock();
if (finished)
return;
sp.mutex.lock();
nodes += sp.nodes;
- Bitboard sm = sp.slavesMask;
- while (sm)
- {
- Position* pos = Threads[pop_lsb(&sm)]->activePosition;
- if (pos)
- nodes += pos->nodes_searched();
- }
+
+ for (size_t idx = 0; idx < Threads.size(); ++idx)
+ if (sp.slavesMask.test(idx) && Threads[idx]->activePosition)
+ nodes += Threads[idx]->activePosition->nodes_searched();
sp.mutex.unlock();
}
projects / stockfish / blobdiff