Value value_to_tt(Value v, int ply);
Value value_from_tt(Value v, int ply);
bool check_is_dangerous(Position& pos, Move move, Value futilityBase, Value beta);
- bool allows_move(const Position& pos, Move first, Move second);
bool prevents_move(const Position& pos, Move first, Move second);
string uci_pv(const Position& pos, int depth, Value alpha, Value beta);
goto finalize;
}
- if (Options["OwnBook"] && !Limits.infinite)
+ if (Options["OwnBook"] && !Limits.infinite && !Limits.mate)
{
Move bookMove = book.probe(RootPos, Options["Book File"], Options["Best Book Move"]);
<< std::endl;
}
- Threads.wake_up();
+ // Reset the threads, still sleeping: will be wake up at split time
+ for (size_t i = 0; i < Threads.size(); i++)
+ Threads[i].maxPly = 0;
+
+ Threads.sleepWhileIdle = Options["Use Sleeping Threads"];
// Set best timer interval to avoid lagging under time pressure. Timer is
// used to check for remaining available thinking time.
- if (Limits.use_time_management())
- Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 16,
- TimerResolution)));
- else if (Limits.nodes)
- Threads.set_timer(2 * TimerResolution);
- else
- Threads.set_timer(100);
+ Threads.timer_thread()->msec =
+ Limits.use_time_management() ? std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution)) :
+ Limits.nodes ? 2 * TimerResolution
+ : 100;
+
+ Threads.timer_thread()->notify_one(); // Wake up the recurring timer
id_loop(RootPos); // Let's start searching !
- Threads.set_timer(0); // Stop timer
- Threads.sleep();
+ Threads.timer_thread()->msec = 0; // Stop the timer
+ Threads.sleepWhileIdle = true; // Send idle threads to sleep
if (Options["Use Search Log"])
{
finalize:
// When we reach max depth we arrive here even without Signals.stop is raised,
- // but if we are pondering or in infinite search, we shouldn't print the best
- // move before we are told to do so.
+ // but if we are pondering or in infinite search, according to UCI protocol,
+ // we shouldn't print the best move before the GUI sends a "stop" or "ponderhit"
+ // command. We simply wait here until GUI sends one of those commands (that
+ // raise Signals.stop).
if (!Signals.stop && (Limits.ponder || Limits.infinite))
- RootPos.this_thread()->wait_for_stop_or_ponderhit();
+ {
+ Signals.stopOnPonderhit = true;
+ RootPos.this_thread()->wait_for(Signals.stop);
+ }
// Best move could be MOVE_NONE when searching on a stalemate position
sync_cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], RootPos.is_chess960())
if (depth > 2 && BestMoveChanges)
bestMoveNeverChanged = false;
+ // Do we have found a "mate in x"?
+ if ( Limits.mate
+ && bestValue >= VALUE_MATE_IN_MAX_PLY
+ && VALUE_MATE - bestValue <= 2 * Limits.mate)
+ Signals.stop = true;
+
// Do we have time for the next iteration? Can we stop searching now?
if (Limits.use_time_management() && !Signals.stopOnPonderhit)
{
Value bestValue, value, ttValue;
Value eval, nullValue, futilityValue;
bool inCheck, givesCheck, pvMove, singularExtensionNode;
- bool captureOrPromotion, dangerous, doFullDepthSearch, threatExtension;
+ bool captureOrPromotion, dangerous, doFullDepthSearch;
int moveCount, playedMoveCount;
// Step 1. Initialize node
Thread* thisThread = pos.this_thread();
moveCount = playedMoveCount = 0;
- threatExtension = false;
inCheck = pos.checkers();
if (SpNode)
// Step 5. Evaluate the position statically and update parent's gain statistics
if (inCheck)
ss->staticEval = ss->evalMargin = eval = VALUE_NONE;
- else
+
+ else if (tte)
{
- eval = ss->staticEval = evaluate(pos, ss->evalMargin);
+ // Never assume anything on values stored in TT
+ if ( (ss->staticEval = eval = tte->static_value()) == VALUE_NONE
+ ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE)
+ eval = ss->staticEval = evaluate(pos, ss->evalMargin);
// Can ttValue be used as a better position evaluation?
- if (tte && ttValue != VALUE_NONE)
- {
+ if (ttValue != VALUE_NONE)
if ( ((tte->type() & BOUND_LOWER) && ttValue > eval)
|| ((tte->type() & BOUND_UPPER) && ttValue < eval))
eval = ttValue;
- }
+ }
+ else
+ {
+ eval = ss->staticEval = evaluate(pos, ss->evalMargin);
+ TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE,
+ ss->staticEval, ss->evalMargin);
}
// Update gain for the parent non-capture move given the static position
return nullValue;
}
else
- {
// The null move failed low, which means that we may be faced with
- // some kind of threat. If the previous move was reduced, check if
- // the move that refuted the null move was somehow connected to the
- // move which was reduced. If a connection is found extend moves that
- // defend against threat.
+ // some kind of threat.
threatMove = (ss+1)->currentMove;
-
- if ( depth < 5 * ONE_PLY
- && (ss-1)->reduction
- && threatMove != MOVE_NONE
- && allows_move(pos, (ss-1)->currentMove, threatMove))
- threatExtension = true;
- }
}
// Step 9. ProbCut (is omitted in PV nodes)
if (PvNode && dangerous)
ext = ONE_PLY;
- else if (threatExtension && prevents_move(pos, move, threatMove))
- ext = ONE_PLY;
-
else if (givesCheck && pos.see_sign(move) >= 0)
ext = ONE_PLY / 2;
&& !inCheck
&& !dangerous
&& move != ttMove
+ && (!threatMove || !prevents_move(pos, move, threatMove))
&& (bestValue > VALUE_MATED_IN_MAX_PLY || ( bestValue == -VALUE_INFINITE
&& alpha > VALUE_MATED_IN_MAX_PLY)))
{
// Move count based pruning
- if ( depth < 16 * ONE_PLY
- && moveCount >= FutilityMoveCounts[depth]
- && (!threatMove || !prevents_move(pos, move, threatMove)))
+ if (depth < 16 * ONE_PLY && moveCount >= FutilityMoveCounts[depth])
{
if (SpNode)
sp->mutex.lock();
continue;
}
- pvMove = PvNode ? moveCount == 1 : false;
+ pvMove = PvNode && moveCount == 1;
ss->currentMove = move;
if (!SpNode && !captureOrPromotion && playedMoveCount < 64)
movesSearched[playedMoveCount++] = move;
if (value > bestValue)
{
- bestValue = value;
- if (SpNode) sp->bestValue = value;
+ bestValue = SpNode ? sp->bestValue = value : value;
if (value > alpha)
{
- bestMove = move;
- if (SpNode) sp->bestMove = move;
+ bestMove = SpNode ? sp->bestMove = move : move;
- if (PvNode && value < beta)
- {
- alpha = value; // Update alpha here! Always alpha < beta
- if (SpNode) sp->alpha = value;
- }
+ if (PvNode && value < beta) // Update alpha! Always alpha < beta
+ alpha = SpNode ? sp->alpha = value : value;
else
{
assert(value >= beta); // Fail high
- if (SpNode) sp->cutoff = true;
+ if (SpNode)
+ sp->cutoff = true;
+
break;
}
}
if (bestValue >= beta) // Failed high
{
- TT.store(posKey, value_to_tt(bestValue, ss->ply), BOUND_LOWER, depth, bestMove);
+ TT.store(posKey, value_to_tt(bestValue, ss->ply), BOUND_LOWER, depth,
+ bestMove, ss->staticEval, ss->evalMargin);
if (!pos.is_capture_or_promotion(bestMove) && !inCheck)
{
else // Failed low or PV search
TT.store(posKey, value_to_tt(bestValue, ss->ply),
PvNode && bestMove != MOVE_NONE ? BOUND_EXACT : BOUND_UPPER,
- depth, bestMove);
+ depth, bestMove, ss->staticEval, ss->evalMargin);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
Key posKey;
Move ttMove, move, bestMove;
Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
- bool givesCheck, enoughMaterial, evasionPrunable, fromNull;
+ bool givesCheck, enoughMaterial, evasionPrunable;
Depth ttDepth;
// To flag BOUND_EXACT a node with eval above alpha and no available moves
ss->currentMove = bestMove = MOVE_NONE;
ss->ply = (ss-1)->ply + 1;
- fromNull = (ss-1)->currentMove == MOVE_NULL;
// Check for an instant draw or maximum ply reached
if (pos.is_draw<false, false>() || ss->ply > MAX_PLY)
}
else
{
- if (fromNull)
+ if (tte)
{
- // Approximated score. Real one is slightly higher due to tempo
- ss->staticEval = bestValue = -(ss-1)->staticEval;
- ss->evalMargin = VALUE_ZERO;
+ // Never assume anything on values stored in TT
+ if ( (ss->staticEval = bestValue = tte->static_value()) == VALUE_NONE
+ ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE)
+ ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
}
else
ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
if (bestValue >= beta)
{
if (!tte)
- TT.store(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER, DEPTH_NONE, MOVE_NONE);
+ TT.store(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER,
+ DEPTH_NONE, MOVE_NONE, ss->staticEval, ss->evalMargin);
return bestValue;
}
// Futility pruning
if ( !PvNode
&& !InCheck
- && !fromNull
&& !givesCheck
&& move != ttMove
&& enoughMaterial
}
else // Fail high
{
- TT.store(posKey, value_to_tt(value, ss->ply), BOUND_LOWER, ttDepth, move);
+ TT.store(posKey, value_to_tt(value, ss->ply), BOUND_LOWER,
+ ttDepth, move, ss->staticEval, ss->evalMargin);
+
return value;
}
}
TT.store(posKey, value_to_tt(bestValue, ss->ply),
PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER,
- ttDepth, bestMove);
+ ttDepth, bestMove, ss->staticEval, ss->evalMargin);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
}
- // allows_move() tests whether the move at previous ply (first) somehow makes a
- // second move possible, for instance if the moving piece is the same in both
- // moves. Normally the second move is the threat move (the best move returned
- // from a null search that fails low).
-
- bool allows_move(const Position& pos, Move first, Move second) {
-
- assert(is_ok(first));
- assert(is_ok(second));
- assert(color_of(pos.piece_on(from_sq(second))) == ~pos.side_to_move());
- assert(color_of(pos.piece_on(to_sq(first))) == ~pos.side_to_move());
-
- Square m1from = from_sq(first);
- Square m2from = from_sq(second);
- Square m1to = to_sq(first);
- Square m2to = to_sq(second);
-
- // The piece is the same or second's destination was vacated by the first move
- if (m1to == m2from || m2to == m1from)
- return true;
-
- // Second one moves through the square vacated by first one
- if (between_bb(m2from, m2to) & m1from)
- return true;
-
- // Second's destination is defended by the first move's piece
- Bitboard m1att = pos.attacks_from(pos.piece_on(m1to), m1to, pos.pieces() ^ m2from);
- if (m1att & m2to)
- return true;
-
- // Second move gives a discovered check through the first's checking piece
- if (m1att & pos.king_square(pos.side_to_move()))
- {
- assert(between_bb(m1to, pos.king_square(pos.side_to_move())) & m2from);
- return true;
- }
-
- return false;
- }
-
-
// prevents_move() tests whether a move (first) is able to defend against an
// opponent's move (second). In this case will not be pruned. Normally the
// second move is the threat move (the best move returned from a null search
assert(is_ok(first));
assert(is_ok(second));
- assert(!pos.is_capture_or_promotion(first));
- assert(!pos.is_passed_pawn_push(first));
Square m1from = from_sq(first);
Square m2from = from_sq(second);
tte = TT.probe(pos.key());
if (!tte || tte->move() != pv[ply]) // Don't overwrite correct entries
- TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply]);
+ TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply], VALUE_NONE, VALUE_NONE);
assert(MoveList<LEGAL>(pos).contains(pv[ply]));
{
// If we are not searching, wait for a condition to be signaled
// instead of wasting CPU time polling for work.
- while ( do_sleep
- || do_exit
- || (!is_searching && Threads.use_sleeping_threads()))
+ while (do_exit || (!is_searching && Threads.sleepWhileIdle))
{
if (do_exit)
{
// particular we need to avoid a deadlock in case a master thread has,
// in the meanwhile, allocated us and sent the wake_up() call before we
// had the chance to grab the lock.
- if (do_sleep || !is_searching)
+ if (!is_searching && Threads.sleepWhileIdle)
sleepCondition.wait(mutex);
mutex.unlock();
// If this thread has been assigned work, launch a search
if (is_searching)
{
- assert(!do_sleep && !do_exit);
+ assert(!do_exit);
Threads.mutex.lock();
// Wake up 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.use_sleeping_threads()
+ if ( Threads.sleepWhileIdle
&& this != sp->master
&& !sp->slavesMask)
{
assert(!sp->master->is_searching);
- sp->master->wake_up();
+ sp->master->notify_one();
}
// After releasing the lock we cannot access anymore any SplitPoint
projects / stockfish / blobdiff