/// Types
enum NodeType { NonPV, PV };
+ // Set to true to force running with one thread.
+ // Used for debugging SMP code.
+ const bool FakeSplit = false;
+
// ThreadsManager class is used to handle all the threads related stuff in search,
// init, starting, parking and, the most important, launching a slave thread at a
// split point are what this class does. All the access to shared thread data is
void wake_sleeping_threads();
void put_threads_to_sleep();
void idle_loop(int threadID, SplitPoint* sp);
- bool split(const Position& pos, SearchStack* ss, int ply, Value* alpha, const Value beta, Value* bestValue,
- Depth depth, bool mateThreat, int* moves, MovePicker* mp, int master, bool pvNode);
+
+ template <bool Fake>
+ void split(const Position& pos, SearchStack* ss, Value* alpha, const Value beta, Value* bestValue,
+ Depth depth, bool mateThreat, int* moveCount, MovePicker* mp, int master, bool pvNode);
private:
friend void poll();
// RootMove::operator<() is the comparison function used when
// sorting the moves. A move m1 is considered to be better
// than a move m2 if it has a higher score, or if the moves
- // have equal score but m1 has the higher node count.
+ // have equal score but m1 has the higher beta cut-off count.
bool operator<(const RootMove& m) const {
return score != m.score ? score < m.score : theirBeta <= m.theirBeta;
// Step 9. Internal iterative deepening
// Minimum depth for use of internal iterative deepening
- const Depth IIDDepthAtPVNodes = 5 * OnePly;
- const Depth IIDDepthAtNonPVNodes = 8 * OnePly;
+ const Depth IIDDepth[2] = { 8 * OnePly /* non-PV */, 5 * OnePly /* PV */};
// At Non-PV nodes we do an internal iterative deepening search
- // when the static evaluation is at most IIDMargin below beta.
+ // when the static evaluation is bigger then beta - IIDMargin.
const Value IIDMargin = Value(0x100);
// Step 11. Decide the new search depth
/// Local functions
Value id_loop(const Position& pos, Move searchMoves[]);
- Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value* alphaPtr, Value* betaPtr);
+ Value root_search(Position& pos, SearchStack* ss, RootMoveList& rml, Value* alphaPtr, Value* betaPtr);
template <NodeType PvNode>
- Value search(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, bool allowNullmove, int threadID, Move excludedMove = MOVE_NONE);
+ Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, bool allowNullmove, int threadID, Move excludedMove = MOVE_NONE);
template <NodeType PvNode>
- Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool singleEvasion, bool mateThreat, bool* dangerous);
+ Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int threadID);
- Value qsearch(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
+ template <NodeType PvNode>
void sp_search(SplitPoint* sp, int threadID);
- void sp_search_pv(SplitPoint* sp, int threadID);
- void init_node(SearchStack ss[], int ply, int threadID);
- void update_pv(SearchStack ss[], int ply);
- void sp_update_pv(SearchStack* pss, SearchStack ss[], int ply);
+
+ template <NodeType PvNode>
+ Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool singleEvasion, bool mateThreat, bool* dangerous);
+
+ void init_node(SearchStack* ss, int ply, int threadID);
+ void update_pv(SearchStack* ss, int ply);
+ void sp_update_pv(SearchStack* pss, SearchStack* ss, int ply);
bool connected_moves(const Position& pos, Move m1, Move m2);
bool value_is_mate(Value value);
- bool move_is_killer(Move m, const SearchStack& ss);
+ bool move_is_killer(Move m, SearchStack* ss);
bool ok_to_do_nullmove(const Position& pos);
bool ok_to_prune(const Position& pos, Move m, Move threat);
bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply);
Value refine_eval(const TTEntry* tte, Value defaultEval, int ply);
void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount);
- void update_killers(Move m, SearchStack& ss);
+ void update_killers(Move m, SearchStack* ss);
void update_gains(const Position& pos, Move move, Value before, Value after);
int current_search_time();
void poll();
void ponderhit();
void wait_for_stop_or_ponderhit();
- void init_ss_array(SearchStack ss[]);
- void print_pv_info(const Position& pos, SearchStack ss[], Value alpha, Value beta, Value value);
+ void init_ss_array(SearchStack* ss);
+ void print_pv_info(const Position& pos, SearchStack* ss, Value alpha, Value beta, Value value);
#if !defined(_MSC_VER)
void *init_thread(void *threadID);
H.clear();
init_ss_array(ss);
ValueByIteration[1] = rml.get_move_score(0);
+ p.reset_ply();
Iteration = 1;
// Is one move significantly better than others after initial scoring ?
// Write PV to transposition table, in case the relevant entries have
// been overwritten during the search.
- TT.insert_pv(p, ss[0].pv);
+ TT.insert_pv(p, ss->pv);
if (AbortSearch)
break; // Value cannot be trusted. Break out immediately!
ValueByIteration[Iteration] = value;
// Drop the easy move if differs from the new best move
- if (ss[0].pv[0] != EasyMove)
+ if (ss->pv[0] != EasyMove)
EasyMove = MOVE_NONE;
if (UseTimeManagement)
// Stop search early if one move seems to be much better than the others
int64_t nodes = TM.nodes_searched();
if ( Iteration >= 8
- && EasyMove == ss[0].pv[0]
+ && EasyMove == ss->pv[0]
&& ( ( rml.get_move_cumulative_nodes(0) > (nodes * 85) / 100
&& current_search_time() > MaxSearchTime / 16)
||( rml.get_move_cumulative_nodes(0) > (nodes * 98) / 100
<< " hashfull " << TT.full() << endl;
// Print the best move and the ponder move to the standard output
- if (ss[0].pv[0] == MOVE_NONE)
+ if (ss->pv[0] == MOVE_NONE)
{
- ss[0].pv[0] = rml.get_move(0);
- ss[0].pv[1] = MOVE_NONE;
+ ss->pv[0] = rml.get_move(0);
+ ss->pv[1] = MOVE_NONE;
}
- assert(ss[0].pv[0] != MOVE_NONE);
+ assert(ss->pv[0] != MOVE_NONE);
- cout << "bestmove " << ss[0].pv[0];
+ cout << "bestmove " << ss->pv[0];
- if (ss[0].pv[1] != MOVE_NONE)
- cout << " ponder " << ss[0].pv[1];
+ if (ss->pv[1] != MOVE_NONE)
+ cout << " ponder " << ss->pv[1];
cout << endl;
LogFile << "\nNodes: " << TM.nodes_searched()
<< "\nNodes/second: " << nps()
- << "\nBest move: " << move_to_san(p, ss[0].pv[0]);
+ << "\nBest move: " << move_to_san(p, ss->pv[0]);
StateInfo st;
- p.do_move(ss[0].pv[0], st);
+ p.do_move(ss->pv[0], st);
LogFile << "\nPonder move: "
- << move_to_san(p, ss[0].pv[1]) // Works also with MOVE_NONE
+ << move_to_san(p, ss->pv[1]) // Works also with MOVE_NONE
<< endl;
}
return rml.get_move_score(0);
// scheme, prints some information to the standard output and handles
// the fail low/high loops.
- Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value* alphaPtr, Value* betaPtr) {
+ Value root_search(Position& pos, SearchStack* ss, RootMoveList& rml, Value* alphaPtr, Value* betaPtr) {
EvalInfo ei;
StateInfo st;
beta = *betaPtr;
isCheck = pos.is_check();
- // Step 1. Initialize node and poll (omitted at root, but I can see no good reason for this, FIXME)
- // Step 2. Check for aborted search (omitted at root, because we do not initialize root node)
+ // Step 1. Initialize node and poll (omitted at root, init_ss_array() has already initialized root node)
+ // Step 2. Check for aborted search (omitted at root)
// Step 3. Mate distance pruning (omitted at root)
// Step 4. Transposition table lookup (omitted at root)
// Step 5. Evaluate the position statically
// At root we do this only to get reference value for child nodes
if (!isCheck)
- ss[0].eval = evaluate(pos, ei, 0);
- else
- ss[0].eval = VALUE_NONE; // HACK because we do not initialize root node
+ ss->eval = evaluate(pos, ei, 0);
// Step 6. Razoring (omitted at root)
// Step 7. Static null move pruning (omitted at root)
// Pick the next root move, and print the move and the move number to
// the standard output.
- move = ss[0].currentMove = rml.get_move(i);
+ move = ss->currentMove = rml.get_move(i);
if (current_search_time() >= 1000)
cout << "info currmove " << move
alpha = -VALUE_INFINITE;
// Full depth PV search, done on first move or after a fail high
- value = -search<PV>(pos, ss, -beta, -alpha, newDepth, 1, false, 0);
+ value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, false, 0);
}
else
{
&& !captureOrPromotion
&& !move_is_castle(move))
{
- ss[0].reduction = reduction<PV>(depth, i - MultiPV + 2);
- if (ss[0].reduction)
+ ss->reduction = reduction<PV>(depth, i - MultiPV + 2);
+ if (ss->reduction)
{
// Reduced depth non-pv search using alpha as upperbound
- value = -search<NonPV>(pos, ss, -(alpha+1), -alpha, newDepth-ss[0].reduction, 1, true, 0);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, true, 0);
doFullDepthSearch = (value > alpha);
}
}
if (doFullDepthSearch)
{
// Full depth non-pv search using alpha as upperbound
- ss[0].reduction = Depth(0);
- value = -search<NonPV>(pos, ss, -(alpha+1), -alpha, newDepth, 1, true, 0);
+ ss->reduction = Depth(0);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth, true, 0);
// If we are above alpha then research at same depth but as PV
// to get a correct score or eventually a fail high above beta.
if (value > alpha)
- value = -search<PV>(pos, ss, -beta, -alpha, newDepth, 1, false, 0);
+ value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, false, 0);
}
}
// the score before research in case we run out of time while researching.
rml.set_move_score(i, value);
update_pv(ss, 0);
- TT.extract_pv(pos, ss[0].pv, PLY_MAX);
- rml.set_move_pv(i, ss[0].pv);
+ TT.extract_pv(pos, ss->pv, PLY_MAX);
+ rml.set_move_pv(i, ss->pv);
// Print information to the standard output
print_pv_info(pos, ss, alpha, beta, value);
// Update PV
rml.set_move_score(i, value);
update_pv(ss, 0);
- TT.extract_pv(pos, ss[0].pv, PLY_MAX);
- rml.set_move_pv(i, ss[0].pv);
+ TT.extract_pv(pos, ss->pv, PLY_MAX);
+ rml.set_move_pv(i, ss->pv);
if (MultiPV == 1)
{
}
- // search_pv() is the main search function for PV nodes.
+ // search<>() is the main search function for both PV and non-PV nodes
template <NodeType PvNode>
- Value search(Position& pos, SearchStack ss[], Value alpha, Value beta,
- Depth depth, int ply, bool allowNullmove, int threadID, Move excludedMove) {
+ Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth,
+ bool allowNullmove, int threadID, Move excludedMove) {
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta > alpha && beta <= VALUE_INFINITE);
- assert(ply >= 0 && ply < PLY_MAX);
+ assert(PvNode || alpha == beta - 1);
+ assert(pos.ply() > 0 && pos.ply() < PLY_MAX);
assert(threadID >= 0 && threadID < TM.active_threads());
Move movesSearched[256];
bool isCheck, singleEvasion, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
int moveCount = 0;
+ int ply = pos.ply();
refinedValue = bestValue = value = -VALUE_INFINITE;
oldAlpha = alpha;
if (depth < OnePly)
- return qsearch(pos, ss, alpha, beta, Depth(0), ply, threadID);
+ return qsearch<PvNode>(pos, ss, alpha, beta, Depth(0), threadID);
// Step 1. Initialize node and poll
// Polling can abort search.
if (!PvNode && tte && ok_to_use_TT(tte, depth, beta, ply))
{
// Refresh tte entry to avoid aging
- TT.store(posKey, tte->value(), tte->type(), tte->depth(), ttMove);
+ TT.store(posKey, tte->value(), tte->type(), tte->depth(), ttMove, tte->static_value(), tte->king_danger());
- ss[ply].currentMove = ttMove; // Can be MOVE_NONE
+ ss->currentMove = ttMove; // Can be MOVE_NONE
return value_from_tt(tte->value(), ply);
}
isCheck = pos.is_check();
if (!isCheck)
{
- if (!PvNode && tte && (tte->type() & VALUE_TYPE_EVAL))
- ss[ply].eval = value_from_tt(tte->value(), ply);
+ if (tte && tte->static_value() != VALUE_NONE)
+ {
+ ss->eval = tte->static_value();
+ ei.kingDanger[pos.side_to_move()] = tte->king_danger();
+ }
else
- ss[ply].eval = evaluate(pos, ei, threadID);
+ ss->eval = evaluate(pos, ei, threadID);
- refinedValue = refine_eval(tte, ss[ply].eval, ply); // Enhance accuracy with TT value if possible
- update_gains(pos, ss[ply - 1].currentMove, ss[ply - 1].eval, ss[ply].eval);
+ refinedValue = refine_eval(tte, ss->eval, ply); // Enhance accuracy with TT value if possible
+ update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval);
}
// Step 6. Razoring (is omitted in PV nodes)
if ( !PvNode
&& refinedValue < beta - razor_margin(depth)
&& ttMove == MOVE_NONE
- && ss[ply - 1].currentMove != MOVE_NULL
+ && (ss-1)->currentMove != MOVE_NULL
&& depth < RazorDepth
&& !isCheck
&& !value_is_mate(beta)
&& !pos.has_pawn_on_7th(pos.side_to_move()))
{
Value rbeta = beta - razor_margin(depth);
- Value v = qsearch(pos, ss, rbeta-1, rbeta, Depth(0), ply, threadID);
+ Value v = qsearch<NonPV>(pos, ss, rbeta-1, rbeta, Depth(0), threadID);
if (v < rbeta)
// Logically we should return (v + razor_margin(depth)), but
// surprisingly this did slightly weaker in tests.
&& ok_to_do_nullmove(pos)
&& refinedValue >= beta - (depth >= 4 * OnePly ? NullMoveMargin : 0))
{
- ss[ply].currentMove = MOVE_NULL;
+ ss->currentMove = MOVE_NULL;
// Null move dynamic reduction based on depth
int R = 3 + (depth >= 5 * OnePly ? depth / 8 : 0);
pos.do_null_move(st);
- nullValue = -search<NonPV>(pos, ss, -beta, -alpha, depth-R*OnePly, ply+1, false, threadID);
+ nullValue = -search<NonPV>(pos, ss+1, -beta, -alpha, depth-R*OnePly, false, threadID);
pos.undo_null_move();
return nullValue;
// Do zugzwang verification search
- Value v = search<NonPV>(pos, ss, alpha, beta, depth-5*OnePly, ply, false, threadID);
+ Value v = search<NonPV>(pos, ss, alpha, beta, depth-5*OnePly, false, threadID);
if (v >= beta)
return nullValue;
} else {
if (nullValue == value_mated_in(ply + 2))
mateThreat = true;
- ss[ply].threatMove = ss[ply + 1].currentMove;
+ ss->threatMove = (ss+1)->currentMove;
if ( depth < ThreatDepth
- && ss[ply - 1].reduction
- && connected_moves(pos, ss[ply - 1].currentMove, ss[ply].threatMove))
+ && (ss-1)->reduction
+ && connected_moves(pos, (ss-1)->currentMove, ss->threatMove))
return beta - 1;
}
}
// Step 9. Internal iterative deepening
- // We have different rules for PV nodes and non-pv nodes
- if ( PvNode
- && depth >= IIDDepthAtPVNodes
- && ttMove == MOVE_NONE)
- {
- search<PV>(pos, ss, alpha, beta, depth-2*OnePly, ply, false, threadID);
- ttMove = ss[ply].pv[ply];
- tte = TT.retrieve(posKey);
- }
-
- if ( !PvNode
- && depth >= IIDDepthAtNonPVNodes
- && ttMove == MOVE_NONE
- && !isCheck
- && ss[ply].eval >= beta - IIDMargin)
+ if ( depth >= IIDDepth[PvNode]
+ && (ttMove == MOVE_NONE || (PvNode && tte->depth() <= depth - 4 * OnePly))
+ && (PvNode || (!isCheck && ss->eval >= beta - IIDMargin)))
{
- search<NonPV>(pos, ss, alpha, beta, depth/2, ply, false, threadID);
- ttMove = ss[ply].pv[ply];
+ Depth d = (PvNode ? depth - 2 * OnePly : depth / 2);
+ search<PvNode>(pos, ss, alpha, beta, d, false, threadID);
+ ttMove = ss->pv[ply];
tte = TT.retrieve(posKey);
}
mateThreat = pos.has_mate_threat(opposite_color(pos.side_to_move()));
// Initialize a MovePicker object for the current position
- MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply], (PvNode ? -VALUE_INFINITE : beta));
+ MovePicker mp = MovePicker(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta));
CheckInfo ci(pos);
// Step 10. Loop through moves
if (abs(ttValue) < VALUE_KNOWN_WIN)
{
- Value excValue = search<NonPV>(pos, ss, ttValue - SingularExtensionMargin - 1, ttValue - SingularExtensionMargin, depth / 2, ply, false, threadID, move);
+ Value b = ttValue - SingularExtensionMargin;
+ Value v = search<NonPV>(pos, ss, b - 1, b, depth / 2, false, threadID, move);
- if (excValue < ttValue - SingularExtensionMargin)
+ if (v < ttValue - SingularExtensionMargin)
ext = OnePly;
}
}
newDepth = depth - OnePly + ext;
// Update current move (this must be done after singular extension search)
- movesSearched[moveCount++] = ss[ply].currentMove = move;
+ movesSearched[moveCount++] = ss->currentMove = move;
// Step 12. Futility pruning (is omitted in PV nodes)
if ( !PvNode
{
// Move count based pruning
if ( moveCount >= futility_move_count(depth)
- && ok_to_prune(pos, move, ss[ply].threatMove)
+ && ok_to_prune(pos, move, ss->threatMove)
&& bestValue > value_mated_in(PLY_MAX))
continue;
// Value based pruning
- Depth predictedDepth = newDepth - reduction<NonPV>(depth, moveCount); // We illogically ignore reduction condition depth >= 3*OnePly
- futilityValueScaled = ss[ply].eval + futility_margin(predictedDepth, moveCount)
+ // We illogically ignore reduction condition depth >= 3*OnePly for predicted depth,
+ // but fixing this made program slightly weaker.
+ Depth predictedDepth = newDepth - reduction<NonPV>(depth, moveCount);
+ futilityValueScaled = ss->eval + futility_margin(predictedDepth, moveCount)
+ H.gain(pos.piece_on(move_from(move)), move_to(move));
if (futilityValueScaled < beta)
// Step extra. pv search (only in PV nodes)
// The first move in list is the expected PV
if (PvNode && moveCount == 1)
- value = -search<PV>(pos, ss, -beta, -alpha, newDepth, ply+1, false, threadID);
+ value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, false, threadID);
else
{
- // Step 14. Reduced search
- // if the move fails high will be re-searched at full depth.
- bool doFullDepthSearch = true;
-
- if ( depth >= 3 * OnePly
- && !dangerous
- && !captureOrPromotion
- && !move_is_castle(move)
- && !move_is_killer(move, ss[ply]))
- {
- ss[ply].reduction = reduction<PvNode>(depth, moveCount);
- if (ss[ply].reduction)
- {
- value = -search<NonPV>(pos, ss, -(alpha+1), -alpha, newDepth-ss[ply].reduction, ply+1, true, threadID);
- doFullDepthSearch = (value > alpha);
- }
- }
-
- // Step 15. Full depth search
- if (doFullDepthSearch)
- {
- ss[ply].reduction = Depth(0);
- value = -search<NonPV>(pos, ss, -(alpha+1), -alpha, newDepth, ply+1, true, threadID);
+ // Step 14. Reduced depth search
+ // If the move fails high will be re-searched at full depth.
+ bool doFullDepthSearch = true;
+
+ if ( depth >= 3 * OnePly
+ && !dangerous
+ && !captureOrPromotion
+ && !move_is_castle(move)
+ && !move_is_killer(move, ss))
+ {
+ ss->reduction = reduction<PvNode>(depth, moveCount);
+ if (ss->reduction)
+ {
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, true, threadID);
+ doFullDepthSearch = (value > alpha);
+ }
+
+ // The move failed high, but if reduction is very big we could
+ // face a false positive, retry with a less aggressive reduction,
+ // if the move fails high again then go with full depth search.
+ if (doFullDepthSearch && ss->reduction > 2 * OnePly)
+ {
+ ss->reduction = OnePly;
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, true, threadID);
+ doFullDepthSearch = (value > alpha);
+ }
+ }
- // Step extra. pv search (only in PV nodes)
- if (PvNode && value > alpha && value < beta)
- value = -search<PV>(pos, ss, -beta, -alpha, newDepth, ply+1, false, threadID);
- }
+ // Step 15. Full depth search
+ if (doFullDepthSearch)
+ {
+ ss->reduction = Depth(0);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth, true, threadID);
+
+ // Step extra. pv search (only in PV nodes)
+ // Search only for possible new PV nodes, if instead value >= beta then
+ // parent node fails low with value <= alpha and tries another move.
+ if (PvNode && value > alpha && value < beta)
+ value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, false, threadID);
+ }
}
// Step 16. Undo move
bestValue = value;
if (value > alpha)
{
- alpha = value;
+ if (PvNode && value < beta) // This guarantees that always: alpha < beta
+ alpha = value;
+
update_pv(ss, ply);
+
if (value == value_mate_in(ply + 1))
- ss[ply].mateKiller = move;
+ ss->mateKiller = move;
}
}
&& Iteration <= 99
&& TM.available_thread_exists(threadID)
&& !AbortSearch
- && !TM.thread_should_stop(threadID)
- && TM.split(pos, ss, ply, &alpha, beta, &bestValue,
- depth, mateThreat, &moveCount, &mp, threadID, PvNode))
- break;
+ && !TM.thread_should_stop(threadID))
+ TM.split<FakeSplit>(pos, ss, &alpha, beta, &bestValue, depth,
+ mateThreat, &moveCount, &mp, threadID, PvNode);
}
// Step 19. Check for mate and stalemate
return bestValue;
if (bestValue <= oldAlpha)
- TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, depth, MOVE_NONE);
+ TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, depth, MOVE_NONE, ss->eval, ei.kingDanger[pos.side_to_move()]);
else if (bestValue >= beta)
{
TM.incrementBetaCounter(pos.side_to_move(), depth, threadID);
- move = ss[ply].pv[ply];
- TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, move);
+ move = ss->pv[ply];
+ TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, depth, move, ss->eval, ei.kingDanger[pos.side_to_move()]);
if (!pos.move_is_capture_or_promotion(move))
{
update_history(pos, move, depth, movesSearched, moveCount);
- update_killers(move, ss[ply]);
+ update_killers(move, ss);
}
}
else
- TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, depth, ss[ply].pv[ply]);
+ TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, depth, ss->pv[ply], ss->eval, ei.kingDanger[pos.side_to_move()]);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
// search function when the remaining depth is zero (or, to be more precise,
// less than OnePly).
- Value qsearch(Position& pos, SearchStack ss[], Value alpha, Value beta,
- Depth depth, int ply, int threadID) {
+ template <NodeType PvNode>
+ Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int threadID) {
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
+ assert(PvNode || alpha == beta - 1);
assert(depth <= 0);
- assert(ply >= 0 && ply < PLY_MAX);
+ assert(pos.ply() > 0 && pos.ply() < PLY_MAX);
assert(threadID >= 0 && threadID < TM.active_threads());
EvalInfo ei;
bool isCheck, enoughMaterial, moveIsCheck, evasionPrunable;
const TTEntry* tte = NULL;
int moveCount = 0;
- bool pvNode = (beta - alpha != 1);
+ int ply = pos.ply();
Value oldAlpha = alpha;
// Initialize, and make an early exit in case of an aborted search,
tte = TT.retrieve(pos.get_key());
ttMove = (tte ? tte->move() : MOVE_NONE);
- if (!pvNode && tte && ok_to_use_TT(tte, depth, beta, ply))
+ if (!PvNode && tte && ok_to_use_TT(tte, depth, beta, ply))
{
- assert(tte->type() != VALUE_TYPE_EVAL);
-
- ss[ply].currentMove = ttMove; // Can be MOVE_NONE
+ ss->currentMove = ttMove; // Can be MOVE_NONE
return value_from_tt(tte->value(), ply);
}
// Evaluate the position statically
if (isCheck)
staticValue = -VALUE_INFINITE;
- else if (tte && (tte->type() & VALUE_TYPE_EVAL))
- staticValue = value_from_tt(tte->value(), ply);
+ else if (tte && tte->static_value() != VALUE_NONE)
+ {
+ staticValue = tte->static_value();
+ ei.kingDanger[pos.side_to_move()] = tte->king_danger();
+ }
else
staticValue = evaluate(pos, ei, threadID);
if (!isCheck)
{
- ss[ply].eval = staticValue;
- update_gains(pos, ss[ply - 1].currentMove, ss[ply - 1].eval, ss[ply].eval);
+ ss->eval = staticValue;
+ update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval);
}
// Initialize "stand pat score", and return it immediately if it is
if (bestValue >= beta)
{
// Store the score to avoid a future costly evaluation() call
- if (!isCheck && !tte && ei.kingDanger[pos.side_to_move()] == 0)
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EV_LO, Depth(-127*OnePly), MOVE_NONE);
+ if (!isCheck && !tte)
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, Depth(-127*OnePly), MOVE_NONE, ss->eval, ei.kingDanger[pos.side_to_move()]);
return bestValue;
}
// Update current move
moveCount++;
- ss[ply].currentMove = move;
+ ss->currentMove = move;
// Futility pruning
- if ( enoughMaterial
+ if ( !PvNode
+ && enoughMaterial
&& !isCheck
- && !pvNode
&& !moveIsCheck
&& move != ttMove
&& !move_is_promotion(move)
&& !pos.can_castle(pos.side_to_move());
// Don't search moves with negative SEE values
- if ( (!isCheck || evasionPrunable)
- && !pvNode
+ if ( !PvNode
+ && (!isCheck || evasionPrunable)
&& move != ttMove
&& !move_is_promotion(move)
&& pos.see_sign(move) < 0)
// Make and search the move
pos.do_move(move, st, ci, moveIsCheck);
- value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID);
+ value = -qsearch<PvNode>(pos, ss+1, -beta, -alpha, depth-OnePly, threadID);
pos.undo_move(move);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
{
// If bestValue isn't changed it means it is still the static evaluation
// of the node, so keep this info to avoid a future evaluation() call.
- ValueType type = (bestValue == staticValue && !ei.kingDanger[pos.side_to_move()] ? VALUE_TYPE_EV_UP : VALUE_TYPE_UPPER);
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), type, d, MOVE_NONE);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, d, MOVE_NONE, ss->eval, ei.kingDanger[pos.side_to_move()]);
}
else if (bestValue >= beta)
{
- move = ss[ply].pv[ply];
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, move);
+ move = ss->pv[ply];
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, move, ss->eval, ei.kingDanger[pos.side_to_move()]);
// Update killers only for good checking moves
if (!pos.move_is_capture_or_promotion(move))
- update_killers(move, ss[ply]);
+ update_killers(move, ss);
}
else
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, d, ss[ply].pv[ply]);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, d, ss->pv[ply], ss->eval, ei.kingDanger[pos.side_to_move()]);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
// 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 PvNode>
void sp_search(SplitPoint* sp, int threadID) {
assert(threadID >= 0 && threadID < TM.active_threads());
StateInfo st;
Move move;
Depth ext, newDepth;
- Value value, futilityValueScaled;
+ Value value;
+ Value futilityValueScaled; // NonPV specific
bool isCheck, moveIsCheck, captureOrPromotion, dangerous;
int moveCount;
value = -VALUE_INFINITE;
Position pos(*sp->pos);
CheckInfo ci(pos);
- SearchStack* ss = sp->sstack[threadID];
+ int ply = pos.ply();
+ SearchStack* ss = sp->sstack[threadID] + 1;
isCheck = pos.is_check();
// Step 10. Loop through moves
lock_grab(&(sp->lock));
while ( sp->bestValue < sp->beta
- && !TM.thread_should_stop(threadID)
- && (move = sp->mp->get_next_move()) != MOVE_NONE)
+ && (move = sp->mp->get_next_move()) != MOVE_NONE
+ && !TM.thread_should_stop(threadID))
{
- moveCount = ++sp->moves;
+ moveCount = ++sp->moveCount;
lock_release(&(sp->lock));
assert(move_is_ok(move));
captureOrPromotion = pos.move_is_capture_or_promotion(move);
// Step 11. Decide the new search depth
- ext = extension<NonPV>(pos, move, captureOrPromotion, moveIsCheck, false, sp->mateThreat, &dangerous);
+ ext = extension<PvNode>(pos, move, captureOrPromotion, moveIsCheck, false, sp->mateThreat, &dangerous);
newDepth = sp->depth - OnePly + ext;
// Update current move
- ss[sp->ply].currentMove = move;
+ ss->currentMove = move;
- // Step 12. Futility pruning
- if ( !isCheck
+ // Step 12. Futility pruning (is omitted in PV nodes)
+ if ( !PvNode
+ && !isCheck
&& !dangerous
&& !captureOrPromotion
&& !move_is_castle(move))
{
// Move count based pruning
if ( moveCount >= futility_move_count(sp->depth)
- && ok_to_prune(pos, move, ss[sp->ply].threatMove)
+ && ok_to_prune(pos, move, ss->threatMove)
&& sp->bestValue > value_mated_in(PLY_MAX))
{
lock_grab(&(sp->lock));
// Value based pruning
Depth predictedDepth = newDepth - reduction<NonPV>(sp->depth, moveCount);
- futilityValueScaled = ss[sp->ply].eval + futility_margin(predictedDepth, moveCount)
+ futilityValueScaled = ss->eval + futility_margin(predictedDepth, moveCount)
+ H.gain(pos.piece_on(move_from(move)), move_to(move));
if (futilityValueScaled < sp->beta)
pos.do_move(move, st, ci, moveIsCheck);
// Step 14. Reduced search
- // if the move fails high will be re-searched at full depth.
+ // If the move fails high will be re-searched at full depth.
bool doFullDepthSearch = true;
if ( !dangerous
&& !captureOrPromotion
&& !move_is_castle(move)
- && !move_is_killer(move, ss[sp->ply]))
+ && !move_is_killer(move, ss))
{
- ss[sp->ply].reduction = reduction<NonPV>(sp->depth, moveCount);
- if (ss[sp->ply].reduction)
+ ss->reduction = reduction<PvNode>(sp->depth, moveCount);
+ if (ss->reduction)
{
- value = -search<NonPV>(pos, ss, -(sp->alpha+1), -(sp->alpha), newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID);
- doFullDepthSearch = (value >= sp->beta && !TM.thread_should_stop(threadID));
+ Value localAlpha = sp->alpha;
+ value = -search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth-ss->reduction, true, threadID);
+ doFullDepthSearch = (value > localAlpha);
}
- }
-
- // Step 15. Full depth search
- if (doFullDepthSearch)
- {
- ss[sp->ply].reduction = Depth(0);
- value = -search<NonPV>(pos, ss, -(sp->alpha+1), -(sp->alpha), newDepth, sp->ply+1, true, threadID);
- }
- // Step 16. Undo move
- pos.undo_move(move);
-
- assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
-
- // Step 17. Check for new best move
- lock_grab(&(sp->lock));
-
- if (value > sp->bestValue && !TM.thread_should_stop(threadID))
- {
- sp->bestValue = value;
- if (sp->bestValue >= sp->beta)
- {
- sp->stopRequest = true;
- sp_update_pv(sp->parentSstack, ss, sp->ply);
- }
- }
- }
-
- /* Here we have the lock still grabbed */
-
- sp->slaves[threadID] = 0;
- sp->cpus--;
-
- lock_release(&(sp->lock));
- }
-
-
- // sp_search_pv() is used to search from a PV split point. This function
- // is called by each thread working at the split point. It is similar to
- // the normal search_pv() function, but simpler. Because we have already
- // probed the hash table and searched the first move before splitting, we
- // don't have to repeat all this work in sp_search_pv(). 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.
-
- void sp_search_pv(SplitPoint* sp, int threadID) {
-
- assert(threadID >= 0 && threadID < TM.active_threads());
- assert(TM.active_threads() > 1);
-
- StateInfo st;
- Move move;
- Depth ext, newDepth;
- Value value;
- bool moveIsCheck, captureOrPromotion, dangerous;
- int moveCount;
- value = -VALUE_INFINITE;
-
- Position pos(*sp->pos);
- CheckInfo ci(pos);
- SearchStack* ss = sp->sstack[threadID];
-
- // Step 10. Loop through moves
- // Loop through all legal moves until no moves remain or a beta cutoff occurs
- lock_grab(&(sp->lock));
-
- while ( sp->alpha < sp->beta
- && !TM.thread_should_stop(threadID)
- && (move = sp->mp->get_next_move()) != MOVE_NONE)
- {
- moveCount = ++sp->moves;
- lock_release(&(sp->lock));
-
- assert(move_is_ok(move));
-
- moveIsCheck = pos.move_is_check(move, ci);
- captureOrPromotion = pos.move_is_capture_or_promotion(move);
-
- // Step 11. Decide the new search depth
- ext = extension<PV>(pos, move, captureOrPromotion, moveIsCheck, false, sp->mateThreat, &dangerous);
- newDepth = sp->depth - OnePly + ext;
-
- // Update current move
- ss[sp->ply].currentMove = move;
-
- // Step 12. Futility pruning (is omitted in PV nodes)
-
- // Step 13. Make the move
- pos.do_move(move, st, ci, moveIsCheck);
-
- // Step 14. Reduced search
- // if the move fails high will be re-searched at full depth.
- bool doFullDepthSearch = true;
-
- if ( !dangerous
- && !captureOrPromotion
- && !move_is_castle(move)
- && !move_is_killer(move, ss[sp->ply]))
- {
- ss[sp->ply].reduction = reduction<PV>(sp->depth, moveCount);
- if (ss[sp->ply].reduction)
+ // The move failed high, but if reduction is very big we could
+ // face a false positive, retry with a less aggressive reduction,
+ // if the move fails high again then go with full depth search.
+ if (doFullDepthSearch && ss->reduction > 2 * OnePly)
{
+ ss->reduction = OnePly;
Value localAlpha = sp->alpha;
- value = -search<NonPV>(pos, ss, -(localAlpha+1), -localAlpha, newDepth-ss[sp->ply].reduction, sp->ply+1, true, threadID);
- doFullDepthSearch = (value > localAlpha && !TM.thread_should_stop(threadID));
+ value = -search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth-ss->reduction, true, threadID);
+ doFullDepthSearch = (value > localAlpha);
}
}
// Step 15. Full depth search
if (doFullDepthSearch)
{
+ ss->reduction = Depth(0);
Value localAlpha = sp->alpha;
- ss[sp->ply].reduction = Depth(0);
- value = -search<NonPV>(pos, ss, -(localAlpha+1), -localAlpha, newDepth, sp->ply+1, true, threadID);
+ value = -search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth, true, threadID);
- if (value > localAlpha && value < sp->beta && !TM.thread_should_stop(threadID))
- {
- // If another thread has failed high then sp->alpha has been increased
- // to be higher or equal then beta, if so, avoid to start a PV search.
- localAlpha = sp->alpha;
- if (localAlpha < sp->beta)
- value = -search<PV>(pos, ss, -sp->beta, -localAlpha, newDepth, sp->ply+1, false, threadID);
- }
+ if (PvNode && value > localAlpha && value < sp->beta)
+ value = -search<PV>(pos, ss+1, -sp->beta, -sp->alpha, newDepth, false, threadID);
}
// Step 16. Undo move
if (value > sp->bestValue && !TM.thread_should_stop(threadID))
{
sp->bestValue = value;
- if (value > sp->alpha)
+
+ if (sp->bestValue > sp->alpha)
{
- // Ask threads to stop before to modify sp->alpha
- if (value >= sp->beta)
+ if (!PvNode || value >= sp->beta)
sp->stopRequest = true;
- sp->alpha = value;
+ if (PvNode && value < sp->beta) // This guarantees that always: sp->alpha < sp->beta
+ sp->alpha = value;
- sp_update_pv(sp->parentSstack, ss, sp->ply);
- if (value == value_mate_in(sp->ply + 1))
- ss[sp->ply].mateKiller = move;
+ sp_update_pv(sp->parentSstack, ss, ply);
}
}
}
/* Here we have the lock still grabbed */
sp->slaves[threadID] = 0;
- sp->cpus--;
lock_release(&(sp->lock));
}
-
// init_node() is called at the beginning of all the search functions
// (search() qsearch(), and so on) and initializes the
// search stack object corresponding to the current node. Once every
// NodesBetweenPolls nodes, init_node() also calls poll(), which polls
// for user input and checks whether it is time to stop the search.
- void init_node(SearchStack ss[], int ply, int threadID) {
+ void init_node(SearchStack* ss, int ply, int threadID) {
assert(ply >= 0 && ply < PLY_MAX);
assert(threadID >= 0 && threadID < TM.active_threads());
NodesSincePoll = 0;
}
}
- ss[ply].init(ply);
- ss[ply + 2].initKillers();
+ ss->init(ply);
+ (ss + 2)->initKillers();
}
-
// update_pv() is called whenever a search returns a value > alpha.
// It updates the PV in the SearchStack object corresponding to the
// current node.
- void update_pv(SearchStack ss[], int ply) {
+ void update_pv(SearchStack* ss, int ply) {
assert(ply >= 0 && ply < PLY_MAX);
int p;
- ss[ply].pv[ply] = ss[ply].currentMove;
+ ss->pv[ply] = ss->currentMove;
- for (p = ply + 1; ss[ply + 1].pv[p] != MOVE_NONE; p++)
- ss[ply].pv[p] = ss[ply + 1].pv[p];
+ for (p = ply + 1; (ss+1)->pv[p] != MOVE_NONE; p++)
+ ss->pv[p] = (ss+1)->pv[p];
- ss[ply].pv[p] = MOVE_NONE;
+ ss->pv[p] = MOVE_NONE;
}
// difference between the two functions is that sp_update_pv also updates
// the PV at the parent node.
- void sp_update_pv(SearchStack* pss, SearchStack ss[], int ply) {
+ void sp_update_pv(SearchStack* pss, SearchStack* ss, int ply) {
assert(ply >= 0 && ply < PLY_MAX);
int p;
- ss[ply].pv[ply] = pss[ply].pv[ply] = ss[ply].currentMove;
+ ss->pv[ply] = pss->pv[ply] = ss->currentMove;
- for (p = ply + 1; ss[ply + 1].pv[p] != MOVE_NONE; p++)
- ss[ply].pv[p] = pss[ply].pv[p] = ss[ply + 1].pv[p];
+ for (p = ply + 1; (ss+1)->pv[p] != MOVE_NONE; p++)
+ ss->pv[p] = pss->pv[p] = (ss+1)->pv[p];
- ss[ply].pv[p] = pss[ply].pv[p] = MOVE_NONE;
+ ss->pv[p] = pss->pv[p] = MOVE_NONE;
}
// move_is_killer() checks if the given move is among the
// killer moves of that ply.
- bool move_is_killer(Move m, const SearchStack& ss) {
+ bool move_is_killer(Move m, SearchStack* ss) {
- const Move* k = ss.killers;
+ const Move* k = ss->killers;
for (int i = 0; i < KILLER_MAX; i++, k++)
if (*k == m)
return true;
// update_killers() add a good move that produced a beta-cutoff
// among the killer moves of that ply.
- void update_killers(Move m, SearchStack& ss) {
+ void update_killers(Move m, SearchStack* ss) {
- if (m == ss.killers[0])
+ if (m == ss->killers[0])
return;
for (int i = KILLER_MAX - 1; i > 0; i--)
- ss.killers[i] = ss.killers[i - 1];
+ ss->killers[i] = ss->killers[i - 1];
- ss.killers[0] = m;
+ ss->killers[0] = m;
}
// init_ss_array() does a fast reset of the first entries of a SearchStack array
- void init_ss_array(SearchStack ss[]) {
+ void init_ss_array(SearchStack* ss) {
- for (int i = 0; i < 3; i++)
+ for (int i = 0; i < 3; i++, ss++)
{
- ss[i].init(i);
- ss[i].initKillers();
+ ss->init(i);
+ ss->initKillers();
}
}
// print_pv_info() prints to standard output and eventually to log file information on
// the current PV line. It is called at each iteration or after a new pv is found.
- void print_pv_info(const Position& pos, SearchStack ss[], Value alpha, Value beta, Value value) {
+ void print_pv_info(const Position& pos, SearchStack* ss, Value alpha, Value beta, Value value) {
cout << "info depth " << Iteration
<< " score " << value_to_string(value)
<< " nps " << nps()
<< " pv ";
- for (int j = 0; ss[0].pv[j] != MOVE_NONE && j < PLY_MAX; j++)
- cout << ss[0].pv[j] << " ";
+ for (int j = 0; ss->pv[j] != MOVE_NONE && j < PLY_MAX; j++)
+ cout << ss->pv[j] << " ";
cout << endl;
: (value <= alpha ? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT));
LogFile << pretty_pv(pos, current_search_time(), Iteration,
- TM.nodes_searched(), value, type, ss[0].pv) << endl;
+ TM.nodes_searched(), value, type, ss->pv) << endl;
}
}
threads[threadID].state = THREAD_SEARCHING;
if (threads[threadID].splitPoint->pvNode)
- sp_search_pv(threads[threadID].splitPoint, threadID);
+ sp_search<PV>(threads[threadID].splitPoint, threadID);
else
- sp_search(threads[threadID].splitPoint, threadID);
+ sp_search<NonPV>(threads[threadID].splitPoint, threadID);
assert(threads[threadID].state == THREAD_SEARCHING);
threads[threadID].state = THREAD_AVAILABLE;
}
- // If this thread is the master of a split point and all threads have
+ // 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 (sp && sp->cpus == 0)
+ int i = 0;
+ for ( ; sp && i < ActiveThreads && !sp->slaves[i]; i++) {}
+
+ if (i == ActiveThreads)
{
- // Because sp->cpus is decremented under lock protection,
- // be sure sp->lock has been released before to proceed.
+ // Because sp->slaves[] is reset under lock protection,
+ // be sure sp->lock has been released before to return.
lock_grab(&(sp->lock));
lock_release(&(sp->lock));
// split() does the actual work of distributing the work at a node between
- // several threads at PV nodes. If it does not succeed in splitting the
+ // several available threads. If it does not succeed in splitting the
// node (because no idle threads are available, or because we have no unused
- // split point objects), the function immediately returns false. If
- // splitting is possible, a SplitPoint object is initialized with all the
- // data that must be copied to the helper threads (the current position and
- // search stack, alpha, beta, the search depth, etc.), and we tell our
- // helper threads that they have been assigned work. This will cause them
- // to instantly leave their idle loops and call sp_search_pv(). When all
- // threads have returned from sp_search_pv (or, equivalently, when
- // splitPoint->cpus becomes 0), split() returns true.
-
- bool ThreadsManager::split(const Position& p, SearchStack* sstck, int ply,
- Value* alpha, const Value beta, Value* bestValue,
- Depth depth, bool mateThreat, int* moves, MovePicker* mp, int master, bool pvNode) {
-
+ // split point objects), the function immediately returns. If splitting is
+ // possible, a SplitPoint object is initialized with all the data that must be
+ // copied to the helper threads and we tell our helper threads that they have
+ // been assigned work. This will cause them to instantly leave their idle loops
+ // and call sp_search(). When all threads have returned from sp_search() then
+ // split() returns.
+
+ template <bool Fake>
+ void ThreadsManager::split(const Position& p, SearchStack* ss, Value* alpha, const Value beta,
+ Value* bestValue, Depth depth, bool mateThreat, int* moveCount,
+ MovePicker* mp, int master, bool pvNode) {
assert(p.is_ok());
- assert(sstck != NULL);
- assert(ply >= 0 && ply < PLY_MAX);
assert(*bestValue >= -VALUE_INFINITE);
- assert( ( pvNode && *bestValue <= *alpha)
- || (!pvNode && *bestValue < beta ));
- assert(!pvNode || *alpha < beta);
+ assert(*bestValue <= *alpha);
+ assert(*alpha < beta);
assert(beta <= VALUE_INFINITE);
assert(depth > Depth(0));
assert(master >= 0 && master < ActiveThreads);
assert(ActiveThreads > 1);
- SplitPoint* splitPoint;
-
lock_grab(&MPLock);
// If no other thread is available to help us, or if we have too many
|| threads[master].activeSplitPoints >= ACTIVE_SPLIT_POINTS_MAX)
{
lock_release(&MPLock);
- return false;
+ return;
}
// Pick the next available split point object from the split point stack
- splitPoint = &SplitPointStack[master][threads[master].activeSplitPoints];
+ SplitPoint* splitPoint = &SplitPointStack[master][threads[master].activeSplitPoints];
// Initialize the split point object
splitPoint->parent = threads[master].splitPoint;
splitPoint->stopRequest = false;
- splitPoint->ply = ply;
splitPoint->depth = depth;
splitPoint->mateThreat = mateThreat;
splitPoint->alpha = *alpha;
splitPoint->beta = beta;
splitPoint->pvNode = pvNode;
splitPoint->bestValue = *bestValue;
- splitPoint->master = master;
splitPoint->mp = mp;
- splitPoint->moves = *moves;
- splitPoint->cpus = 1;
+ splitPoint->moveCount = *moveCount;
splitPoint->pos = &p;
- splitPoint->parentSstack = sstck;
+ splitPoint->parentSstack = ss;
for (int i = 0; i < ActiveThreads; i++)
splitPoint->slaves[i] = 0;
// If we are here it means we are not available
assert(threads[master].state != THREAD_AVAILABLE);
+ int workersCnt = 1; // At least the master is included
+
// Allocate available threads setting state to THREAD_BOOKED
- for (int i = 0; i < ActiveThreads && splitPoint->cpus < MaxThreadsPerSplitPoint; i++)
+ for (int i = 0; !Fake && i < ActiveThreads && workersCnt < MaxThreadsPerSplitPoint; i++)
if (thread_is_available(i, master))
{
threads[i].state = THREAD_BOOKED;
threads[i].splitPoint = splitPoint;
splitPoint->slaves[i] = 1;
- splitPoint->cpus++;
+ workersCnt++;
}
- assert(splitPoint->cpus > 1);
+ assert(Fake || workersCnt > 1);
// We can release the lock because slave threads are already booked and master is not available
lock_release(&MPLock);
for (int i = 0; i < ActiveThreads; i++)
if (i == master || splitPoint->slaves[i])
{
- memcpy(splitPoint->sstack[i] + ply - 1, sstck + ply - 1, 4 * sizeof(SearchStack));
+ memcpy(splitPoint->sstack[i], ss - 1, 4 * sizeof(SearchStack));
assert(i == master || threads[i].state == THREAD_BOOKED);
// which it will instantly launch a search, because its state is
// THREAD_WORKISWAITING. We send the split point as a second parameter to the
// idle loop, which means that the main thread will return from the idle
- // loop when all threads have finished their work at this split point
- // (i.e. when splitPoint->cpus == 0).
+ // loop when all threads have finished their work at this split point.
idle_loop(master, splitPoint);
// We have returned from the idle loop, which means that all threads are
threads[master].splitPoint = splitPoint->parent;
lock_release(&MPLock);
- return true;
}
init_ss_array(ss);
pos.do_move(cur->move, st);
moves[count].move = cur->move;
- moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0);
+ moves[count].score = -qsearch<PV>(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 0);
moves[count].pv[0] = cur->move;
moves[count].pv[1] = MOVE_NONE;
pos.undo_move(cur->move);