LimitsType Limits;
std::vector<RootMove> RootMoves;
Position RootPosition;
- Time SearchTime;
+ Time::point SearchTime;
+ StateStackPtr SetupStates;
}
using std::string;
-using std::cout;
-using std::endl;
using Eval::evaluate;
using namespace Search;
-// For some reason argument-dependent lookup (ADL) doesn't work for Android's
-// STLPort, so explicitly qualify following functions.
-using std::count;
-using std::find;
-
namespace {
// Set to true to force running with one thread. Used for debugging
const bool FakeSplit = false;
+ // This is the minimum interval in msec between two check_time() calls
+ const int TimerResolution = 5;
+
// Different node types, used as template parameter
enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV };
const bool Slidings[18] = { 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1 };
inline bool piece_is_slider(Piece p) { return Slidings[p]; }
- // Maximum depth for razoring
- const Depth RazorDepth = 4 * ONE_PLY;
-
// Dynamic razoring margin based on depth
inline Value razor_margin(Depth d) { return Value(512 + 16 * int(d)); }
- // Maximum depth for use of dynamic threat detection when null move fails low
- const Depth ThreatDepth = 5 * ONE_PLY;
-
- // Minimum depth for use of internal iterative deepening
- const Depth IIDDepth[] = { 8 * ONE_PLY, 5 * ONE_PLY };
-
- // At Non-PV nodes we do an internal iterative deepening search
- // when the static evaluation is bigger then beta - IIDMargin.
- const Value IIDMargin = Value(256);
-
- // Minimum depth for use of singular extension
- const Depth SingularExtensionDepth[] = { 8 * ONE_PLY, 6 * ONE_PLY };
-
- // Futility margin for quiescence search
- const Value FutilityMarginQS = Value(128);
-
// Futility lookup tables (initialized at startup) and their access functions
Value FutilityMargins[16][64]; // [depth][moveNumber]
int FutilityMoveCounts[32]; // [depth]
: 2 * VALUE_INFINITE;
}
- inline int futility_move_count(Depth d) {
-
- return d < 16 * ONE_PLY ? FutilityMoveCounts[d] : MAX_MOVES;
- }
-
// Reduction lookup tables (initialized at startup) and their access function
int8_t Reductions[2][64][64]; // [pv][depth][moveNumber]
return (Depth) Reductions[PvNode][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)];
}
- // Easy move margin. An easy move candidate must be at least this much better
- // than the second best move.
- const Value EasyMoveMargin = Value(0x150);
-
- // This is the minimum interval in msec between two check_time() calls
- const int TimerResolution = 5;
-
-
size_t MultiPV, UCIMultiPV, PVIdx;
TimeManager TimeMgr;
int BestMoveChanges;
bool SkillLevelEnabled, Chess960;
History H;
-
template <NodeType NT>
Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth);
Move do_skill_level();
string uci_pv(const Position& pos, int depth, Value alpha, Value beta);
- // MovePickerExt class template extends MovePicker and allows to choose at
- // compile time the proper moves source according to the type of node. In the
- // default case we simply create and use a standard MovePicker object.
- template<bool SpNode> struct MovePickerExt : public MovePicker {
-
- MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, Stack* ss, Value b)
- : MovePicker(p, ttm, d, h, ss, b) {}
- };
-
- // In case of a SpNode we use split point's shared MovePicker object as moves source
- template<> struct MovePickerExt<true> : public MovePicker {
-
- MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, Stack* ss, Value b)
- : MovePicker(p, ttm, d, h, ss, b), mp(ss->sp->mp) {}
-
- Move next_move() { return mp->next_move(); }
- MovePicker* mp;
- };
-
// is_dangerous() checks whether a move belongs to some classes of known
// 'dangerous' moves so that we avoid to prune it.
FORCE_INLINE bool is_dangerous(const Position& pos, Move m, bool captureOrPromotion) {
&& type_of(pos.piece_on(to_sq(m))) != PAWN
&& type_of(m) == NORMAL
&& ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK)
- - PieceValueMidgame[pos.piece_on(to_sq(m))] == VALUE_ZERO))
+ - PieceValue[Mg][pos.piece_on(to_sq(m))] == VALUE_ZERO))
return true;
return false;
/// Search::perft() is our utility to verify move generation. All the leaf nodes
/// up to the given depth are generated and counted and the sum returned.
-int64_t Search::perft(Position& pos, Depth depth) {
+size_t Search::perft(Position& pos, Depth depth) {
- StateInfo st;
- int64_t cnt = 0;
-
- MoveList<LEGAL> ml(pos);
-
- // At the last ply just return the number of moves (leaf nodes)
+ // At the last ply just return the number of legal moves (leaf nodes)
if (depth == ONE_PLY)
- return ml.size();
+ return MoveList<LEGAL>(pos).size();
+ StateInfo st;
+ size_t cnt = 0;
CheckInfo ci(pos);
- for ( ; !ml.end(); ++ml)
+
+ for (MoveList<LEGAL> ml(pos); !ml.end(); ++ml)
{
pos.do_move(ml.move(), st, ci, pos.move_gives_check(ml.move(), ci));
cnt += perft(pos, depth - ONE_PLY);
pos.undo_move(ml.move());
}
+
return cnt;
}
void Search::think() {
- static Book book; // Defined static to initialize the PRNG only once
+ static PolyglotBook book; // Defined static to initialize the PRNG only once
Position& pos = RootPosition;
Chess960 = pos.is_chess960();
Eval::RootColor = pos.side_to_move();
+ Eval::ValueDraw[ Eval::RootColor] = VALUE_DRAW - Eval::ContemptFactor;
+ Eval::ValueDraw[~Eval::RootColor] = VALUE_DRAW + Eval::ContemptFactor;
TimeMgr.init(Limits, pos.startpos_ply_counter(), pos.side_to_move());
TT.new_search();
H.clear();
if (RootMoves.empty())
{
- cout << "info depth 0 score "
- << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << endl;
+ sync_cout << "info depth 0 score "
+ << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << sync_endl;
RootMoves.push_back(MOVE_NONE);
goto finalize;
{
Move bookMove = book.probe(pos, Options["Book File"], Options["Best Book Move"]);
- if (bookMove && count(RootMoves.begin(), RootMoves.end(), bookMove))
+ if (bookMove && std::count(RootMoves.begin(), RootMoves.end(), bookMove))
{
- std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), bookMove));
+ std::swap(RootMoves[0], *std::find(RootMoves.begin(), RootMoves.end(), bookMove));
goto finalize;
}
}
<< " time: " << Limits.time[pos.side_to_move()]
<< " increment: " << Limits.inc[pos.side_to_move()]
<< " moves to go: " << Limits.movestogo
- << endl;
+ << std::endl;
}
Threads.wake_up();
// 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);
if (Options["Use Search Log"])
{
- int e = SearchTime.elapsed();
+ Time::point elapsed = Time::now() - SearchTime + 1;
Log log(Options["Search Log Filename"]);
log << "Nodes: " << pos.nodes_searched()
- << "\nNodes/second: " << (e > 0 ? pos.nodes_searched() * 1000 / e : 0)
+ << "\nNodes/second: " << pos.nodes_searched() * 1000 / elapsed
<< "\nBest move: " << move_to_san(pos, RootMoves[0].pv[0]);
StateInfo st;
pos.do_move(RootMoves[0].pv[0], st);
- log << "\nPonder move: " << move_to_san(pos, RootMoves[0].pv[1]) << endl;
+ log << "\nPonder move: " << move_to_san(pos, RootMoves[0].pv[1]) << std::endl;
pos.undo_move(RootMoves[0].pv[0]);
}
pos.this_thread()->wait_for_stop_or_ponderhit();
// Best move could be MOVE_NONE when searching on a stalemate position
- cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], Chess960)
- << " ponder " << move_to_uci(RootMoves[0].pv[1], Chess960) << endl;
+ sync_cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], Chess960)
+ << " ponder " << move_to_uci(RootMoves[0].pv[1], Chess960) << sync_endl;
}
// Start with a small aspiration window and, in case of fail high/low,
// research with bigger window until not failing high/low anymore.
- do {
+ while (true)
+ {
// Search starts from ss+1 to allow referencing (ss-1). This is
// needed by update gains and ss copy when splitting at Root.
bestValue = search<Root>(pos, ss+1, alpha, beta, depth * ONE_PLY);
// Send full PV info to GUI if we are going to leave the loop or
// if we have a fail high/low and we are deep in the search.
- if ((bestValue > alpha && bestValue < beta) || SearchTime.elapsed() > 2000)
- cout << uci_pv(pos, depth, alpha, beta) << endl;
+ if ((bestValue > alpha && bestValue < beta) || Time::now() - SearchTime > 2000)
+ sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl;
// In case of failing high/low increase aspiration window and
// research, otherwise exit the fail high/low loop.
else
break;
- assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
+ // Search with full window in case we have a win/mate score
+ if (abs(bestValue) >= VALUE_KNOWN_WIN)
+ {
+ alpha = -VALUE_INFINITE;
+ beta = VALUE_INFINITE;
+ }
- } while (abs(bestValue) < VALUE_KNOWN_WIN);
+ assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
+ }
}
// Skills: Do we need to pick now the best move ?
if (!Signals.stop && Options["Use Search Log"])
{
Log log(Options["Search Log Filename"]);
- log << pretty_pv(pos, depth, bestValue, SearchTime.elapsed(), &RootMoves[0].pv[0])
- << endl;
+ log << pretty_pv(pos, depth, bestValue, Time::now() - SearchTime, &RootMoves[0].pv[0])
+ << std::endl;
}
// Filter out startup noise when monitoring best move stability
// Stop search if most of available time is already consumed. We
// probably don't have enough time to search the first move at the
// next iteration anyway.
- if (SearchTime.elapsed() > (TimeMgr.available_time() * 62) / 100)
+ if (Time::now() - SearchTime > (TimeMgr.available_time() * 62) / 100)
stop = true;
// Stop search early if one move seems to be much better than others
if ( depth >= 12
&& !stop
&& ( (bestMoveNeverChanged && pos.captured_piece_type())
- || SearchTime.elapsed() > (TimeMgr.available_time() * 40) / 100))
+ || Time::now() - SearchTime > (TimeMgr.available_time() * 40) / 100))
{
- Value rBeta = bestValue - EasyMoveMargin;
+ Value rBeta = bestValue - 2 * PawnValueMg;
(ss+1)->excludedMove = RootMoves[0].pv[0];
(ss+1)->skipNullMove = true;
Value v = search<NonPV>(pos, ss+1, rBeta - 1, rBeta, (depth - 3) * ONE_PLY);
if (skillBest == MOVE_NONE) // Still unassigned ?
skillBest = do_skill_level();
- std::swap(RootMoves[0], *find(RootMoves.begin(), RootMoves.end(), skillBest));
+ std::swap(RootMoves[0], *std::find(RootMoves.begin(), RootMoves.end(), skillBest));
}
}
const bool RootNode = (NT == Root || NT == SplitPointRoot);
assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
- assert((alpha == beta - 1) || PvNode);
+ assert(PvNode || (alpha == beta - 1));
assert(depth > DEPTH_ZERO);
Move movesSearched[64];
StateInfo st;
const TTEntry *tte;
+ SplitPoint* sp;
Key posKey;
Move ttMove, move, excludedMove, bestMove, threatMove;
Depth ext, newDepth;
- Bound bt;
- Value bestValue, value, oldAlpha, ttValue;
- Value refinedValue, nullValue, futilityBase, futilityValue;
- bool isPvMove, inCheck, singularExtensionNode, givesCheck;
+ Value bestValue, value, ttValue;
+ Value refinedValue, nullValue, futilityValue;
+ bool pvMove, inCheck, singularExtensionNode, givesCheck;
bool captureOrPromotion, dangerous, doFullDepthSearch;
- int moveCount = 0, playedMoveCount = 0;
- Thread* thisThread = pos.this_thread();
- SplitPoint* sp = NULL;
+ int moveCount, playedMoveCount;
- refinedValue = bestValue = value = -VALUE_INFINITE;
- oldAlpha = alpha;
+ // Step 1. Initialize node
+ Thread* thisThread = pos.this_thread();
+ moveCount = playedMoveCount = 0;
inCheck = pos.in_check();
- ss->ply = (ss-1)->ply + 1;
- // Used to send selDepth info to GUI
- if (PvNode && thisThread->maxPly < ss->ply)
- thisThread->maxPly = ss->ply;
-
- // Step 1. Initialize node
if (SpNode)
{
- tte = NULL;
- ttMove = excludedMove = MOVE_NONE;
- ttValue = VALUE_ZERO;
sp = ss->sp;
- bestMove = sp->bestMove;
+ bestMove = sp->bestMove;
threatMove = sp->threatMove;
- bestValue = sp->bestValue;
- moveCount = sp->moveCount; // Lock must be held here
+ bestValue = sp->bestValue;
+ tte = NULL;
+ ttMove = excludedMove = MOVE_NONE;
+ ttValue = VALUE_NONE;
- assert(bestValue > -VALUE_INFINITE && moveCount > 0);
+ assert(sp->bestValue > -VALUE_INFINITE && sp->moveCount > 0);
goto split_point_start;
}
- else
- {
- ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
- (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
- (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
- }
+ bestValue = -VALUE_INFINITE;
+ ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
+ ss->ply = (ss-1)->ply + 1;
+ (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
+ (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
+
+ // Used to send selDepth info to GUI
+ if (PvNode && thisThread->maxPly < ss->ply)
+ thisThread->maxPly = ss->ply;
- // Step 2. Check for aborted search and immediate draw
- // Enforce node limit here. FIXME: This only works with 1 search thread.
- if (Limits.nodes && pos.nodes_searched() >= Limits.nodes)
- Signals.stop = true;
-
- if (( Signals.stop
- || pos.is_draw<false>()
- || ss->ply > MAX_PLY) && !RootNode)
- return VALUE_DRAW;
-
- // Step 3. Mate distance pruning. Even if we mate at the next move our score
- // would be at best mate_in(ss->ply+1), but if alpha is already bigger because
- // a shorter mate was found upward in the tree then there is no need to search
- // further, we will never beat current alpha. Same logic but with reversed signs
- // applies also in the opposite condition of being mated instead of giving mate,
- // in this case return a fail-high score.
if (!RootNode)
{
+ // Step 2. Check for aborted search and immediate draw
+ if (Signals.stop || pos.is_draw<false>() || ss->ply > MAX_PLY)
+ return Eval::ValueDraw[pos.side_to_move()];
+
+ // Step 3. Mate distance pruning. Even if we mate at the next move our score
+ // would be at best mate_in(ss->ply+1), but if alpha is already bigger because
+ // a shorter mate was found upward in the tree then there is no need to search
+ // further, we will never beat current alpha. Same logic but with reversed signs
+ // applies also in the opposite condition of being mated instead of giving mate,
+ // in this case return a fail-high score.
alpha = std::max(mated_in(ss->ply), alpha);
beta = std::min(mate_in(ss->ply+1), beta);
if (alpha >= beta)
posKey = excludedMove ? pos.exclusion_key() : pos.key();
tte = TT.probe(posKey);
ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE;
- ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_ZERO;
+ ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
// At PV nodes we check for exact scores, while at non-PV nodes we check for
// a fail high/low. Biggest advantage at probing at PV nodes is to have a
// Step 5. Evaluate the position statically and update parent's gain statistics
if (inCheck)
- ss->eval = ss->evalMargin = VALUE_NONE;
+ ss->eval = ss->evalMargin = refinedValue = VALUE_NONE;
else if (tte)
{
assert(tte->static_value() != VALUE_NONE);
// Step 6. Razoring (is omitted in PV nodes)
if ( !PvNode
- && depth < RazorDepth
+ && depth < 4 * ONE_PLY
&& !inCheck
&& refinedValue + razor_margin(depth) < beta
&& ttMove == MOVE_NONE
// the score by more than futility_margin(depth) if we do a null move.
if ( !PvNode
&& !ss->skipNullMove
- && depth < RazorDepth
+ && depth < 4 * ONE_PLY
&& !inCheck
- && refinedValue - futility_margin(depth, 0) >= beta
+ && refinedValue - FutilityMargins[depth][0] >= beta
&& abs(beta) < VALUE_MATE_IN_MAX_PLY
&& pos.non_pawn_material(pos.side_to_move()))
- return refinedValue - futility_margin(depth, 0);
+ return refinedValue - FutilityMargins[depth][0];
// Step 8. Null move search with verification search (is omitted in PV nodes)
if ( !PvNode
Depth R = 3 * ONE_PLY + depth / 4;
// Null move dynamic reduction based on value
- if (refinedValue - PawnValueMidgame > beta)
+ if (refinedValue - PawnValueMg > beta)
R += ONE_PLY;
pos.do_null_move<true>(st);
// parent node, which will trigger a re-search with full depth).
threatMove = (ss+1)->currentMove;
- if ( depth < ThreatDepth
+ if ( depth < 5 * ONE_PLY
&& (ss-1)->reduction
&& threatMove != MOVE_NONE
&& connected_moves(pos, (ss-1)->currentMove, threatMove))
// and a reduced search returns a value much above beta, we can (almost) safely
// prune the previous move.
if ( !PvNode
- && depth >= RazorDepth + ONE_PLY
+ && depth >= 5 * ONE_PLY
&& !inCheck
&& !ss->skipNullMove
&& excludedMove == MOVE_NONE
MovePicker mp(pos, ttMove, H, pos.captured_piece_type());
CheckInfo ci(pos);
- while ((move = mp.next_move()) != MOVE_NONE)
+ while ((move = mp.next_move<false>()) != MOVE_NONE)
if (pos.pl_move_is_legal(move, ci.pinned))
{
ss->currentMove = move;
}
// Step 10. Internal iterative deepening
- if ( depth >= IIDDepth[PvNode]
+ if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY)
&& ttMove == MOVE_NONE
- && (PvNode || (!inCheck && ss->eval + IIDMargin >= beta)))
+ && (PvNode || (!inCheck && ss->eval + Value(256) >= beta)))
{
Depth d = (PvNode ? depth - 2 * ONE_PLY : depth / 2);
split_point_start: // At split points actual search starts from here
- MovePickerExt<SpNode> mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta);
+ MovePicker mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta);
CheckInfo ci(pos);
- futilityBase = ss->eval + ss->evalMargin;
+ value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
singularExtensionNode = !RootNode
&& !SpNode
- && depth >= SingularExtensionDepth[PvNode]
+ && depth >= (PvNode ? 6 * ONE_PLY : 8 * ONE_PLY)
&& ttMove != MOVE_NONE
&& !excludedMove // Recursive singular search is not allowed
&& (tte->type() & BOUND_LOWER)
// Step 11. Loop through moves
// Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
- while ( bestValue < beta
- && (move = mp.next_move()) != MOVE_NONE
- && !thisThread->cutoff_occurred()
- && !Signals.stop)
+ while ((move = mp.next_move<SpNode>()) != MOVE_NONE)
{
assert(is_ok(move));
// At root obey the "searchmoves" option and skip moves not listed in Root
// Move List, as a consequence any illegal move is also skipped. In MultiPV
// mode we also skip PV moves which have been already searched.
- if (RootNode && !count(RootMoves.begin() + PVIdx, RootMoves.end(), move))
- continue;
-
- // At PV and SpNode nodes we want all moves to be legal since the beginning
- if ((PvNode || SpNode) && !pos.pl_move_is_legal(move, ci.pinned))
+ if (RootNode && !std::count(RootMoves.begin() + PVIdx, RootMoves.end(), move))
continue;
if (SpNode)
{
+ // Shared counter cannot be decremented later if move turns out to be illegal
+ if (!pos.pl_move_is_legal(move, ci.pinned))
+ continue;
+
moveCount = ++sp->moveCount;
- lock_release(sp->lock);
+ sp->mutex.unlock();
}
else
moveCount++;
{
Signals.firstRootMove = (moveCount == 1);
- if (thisThread == Threads.main_thread() && SearchTime.elapsed() > 2000)
- cout << "info depth " << depth / ONE_PLY
- << " currmove " << move_to_uci(move, Chess960)
- << " currmovenumber " << moveCount + PVIdx << endl;
+ if (thisThread == Threads.main_thread() && Time::now() - SearchTime > 2000)
+ sync_cout << "info depth " << depth / ONE_PLY
+ << " currmove " << move_to_uci(move, Chess960)
+ << " currmovenumber " << moveCount + PVIdx << sync_endl;
}
- isPvMove = (PvNode && moveCount <= 1);
captureOrPromotion = pos.is_capture_or_promotion(move);
givesCheck = pos.move_gives_check(move, ci);
dangerous = givesCheck || is_dangerous(pos, move, captureOrPromotion);
ss->excludedMove = MOVE_NONE;
if (value < rBeta)
- ext = ONE_PLY;
+ ext = rBeta >= beta ? ONE_PLY + ONE_PLY / 2 : ONE_PLY;
}
// Update current move (this must be done after singular extension search)
&& (bestValue > VALUE_MATED_IN_MAX_PLY || bestValue == -VALUE_INFINITE))
{
// Move count based pruning
- if ( moveCount >= futility_move_count(depth)
+ if ( depth < 16 * ONE_PLY
+ && moveCount >= FutilityMoveCounts[depth]
&& (!threatMove || !connected_threat(pos, move, threatMove)))
{
if (SpNode)
- lock_grab(sp->lock);
+ sp->mutex.lock();
continue;
}
// We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth,
// but fixing this made program slightly weaker.
Depth predictedDepth = newDepth - reduction<PvNode>(depth, moveCount);
- futilityValue = futilityBase + futility_margin(predictedDepth, moveCount)
+ futilityValue = ss->eval + ss->evalMargin + futility_margin(predictedDepth, moveCount)
+ H.gain(pos.piece_moved(move), to_sq(move));
if (futilityValue < beta)
{
if (SpNode)
- lock_grab(sp->lock);
+ sp->mutex.lock();
continue;
}
&& pos.see_sign(move) < 0)
{
if (SpNode)
- lock_grab(sp->lock);
+ sp->mutex.lock();
continue;
}
continue;
}
+ pvMove = PvNode ? moveCount == 1 : false;
ss->currentMove = move;
if (!SpNode && !captureOrPromotion && playedMoveCount < 64)
movesSearched[playedMoveCount++] = move;
// Step 15. Reduced depth search (LMR). If the move fails high will be
// re-searched at full depth.
if ( depth > 3 * ONE_PLY
- && !isPvMove
+ && !pvMove
&& !captureOrPromotion
&& !dangerous
&& ss->killers[0] != move
ss->reduction = DEPTH_ZERO;
}
else
- doFullDepthSearch = !isPvMove;
+ doFullDepthSearch = !pvMove;
// Step 16. Full depth search, when LMR is skipped or fails high
if (doFullDepthSearch)
// Only for PV nodes 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 to fail low with value <= alpha and to try another move.
- if (PvNode && (isPvMove || (value > alpha && (RootNode || value < beta))))
+ if (PvNode && (pvMove || (value > alpha && (RootNode || value < beta))))
value = newDepth < ONE_PLY ? -qsearch<PV>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
: - search<PV>(pos, ss+1, -beta, -alpha, newDepth);
// Step 18. Check for new best move
if (SpNode)
{
- lock_grab(sp->lock);
+ sp->mutex.lock();
bestValue = sp->bestValue;
alpha = sp->alpha;
}
// 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.
- if (RootNode && !Signals.stop)
+ if (Signals.stop || thisThread->cutoff_occurred())
+ return bestValue;
+
+ if (RootNode)
{
- RootMove& rm = *find(RootMoves.begin(), RootMoves.end(), move);
+ RootMove& rm = *std::find(RootMoves.begin(), RootMoves.end(), move);
// PV move or new best move ?
- if (isPvMove || value > alpha)
+ if (pvMove || 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 (!isPvMove && MultiPV == 1)
+ if (!pvMove && MultiPV == 1)
BestMoveChanges++;
}
else
// is not a problem when sorting becuase sort is stable and move
// position in the list is preserved, just the PV is pushed up.
rm.score = -VALUE_INFINITE;
-
}
if (value > bestValue)
{
bestValue = value;
- bestMove = move;
-
- if ( PvNode
- && value > alpha
- && value < beta) // We want always alpha < beta
- alpha = value;
+ if (SpNode) sp->bestValue = value;
- if (SpNode && !thisThread->cutoff_occurred())
+ if (value > alpha)
{
- sp->bestValue = value;
- sp->bestMove = move;
- sp->alpha = alpha;
-
- if (value >= beta)
- sp->cutoff = true;
+ bestMove = move;
+ if (SpNode) sp->bestMove = move;
+
+ if (PvNode && value < beta)
+ {
+ alpha = value; // Update alpha here! Always alpha < beta
+ if (SpNode) sp->alpha = alpha;
+ }
+ else // Fail high
+ {
+ if (SpNode) sp->cutoff = true;
+ break;
+ }
}
}
- // Step 19. Check for split
+ // Step 19. Check for splitting the search
if ( !SpNode
&& depth >= Threads.min_split_depth()
&& bestValue < beta
- && Threads.available_slave_exists(thisThread)
- && !Signals.stop
- && !thisThread->cutoff_occurred())
+ && Threads.available_slave_exists(thisThread))
+ {
bestValue = Threads.split<FakeSplit>(pos, ss, alpha, beta, bestValue, &bestMove,
- depth, threatMove, moveCount, &mp, NT);
+ depth, threatMove, moveCount, mp, NT);
+ break;
+ }
}
+ if (SpNode)
+ return bestValue;
+
// 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 splitted.
if (!moveCount)
- return excludedMove ? oldAlpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW;
+ return excludedMove ? alpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW;
// If we have pruned all the moves without searching return a fail-low score
if (bestValue == -VALUE_INFINITE)
{
assert(!playedMoveCount);
- bestValue = oldAlpha;
+ bestValue = alpha;
}
- // Step 21. Update tables
- // Update transposition table entry, killers and history
- if (!SpNode && !Signals.stop && !thisThread->cutoff_occurred())
+ if (bestValue >= beta) // Failed high
{
- move = bestValue <= oldAlpha ? MOVE_NONE : bestMove;
- bt = bestValue <= oldAlpha ? BOUND_UPPER
- : bestValue >= beta ? BOUND_LOWER : BOUND_EXACT;
-
- TT.store(posKey, value_to_tt(bestValue, ss->ply), bt, depth, move, ss->eval, ss->evalMargin);
+ TT.store(posKey, value_to_tt(bestValue, ss->ply), BOUND_LOWER, depth,
+ bestMove, ss->eval, ss->evalMargin);
- // Update killers and history for non capture cut-off moves
- if ( bestValue >= beta
- && !pos.is_capture_or_promotion(move)
- && !inCheck)
+ if (!pos.is_capture_or_promotion(bestMove) && !inCheck)
{
- if (move != ss->killers[0])
+ if (bestMove != ss->killers[0])
{
ss->killers[1] = ss->killers[0];
- ss->killers[0] = move;
+ ss->killers[0] = bestMove;
}
// Increase history value of the cut-off move
Value bonus = Value(int(depth) * int(depth));
- H.add(pos.piece_moved(move), to_sq(move), bonus);
+ H.add(pos.piece_moved(bestMove), to_sq(bestMove), bonus);
// Decrease history of all the other played non-capture moves
for (int i = 0; i < playedMoveCount - 1; i++)
}
}
}
+ 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, ss->eval, ss->evalMargin);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
// Check for an instant draw or maximum ply reached
if (pos.is_draw<true>() || ss->ply > MAX_PLY)
- return VALUE_DRAW;
+ return Eval::ValueDraw[pos.side_to_move()];
// Decide whether or not to include checks, this fixes also the type of
// TT entry depth that we are going to use. Note that in qsearch we use
if (PvNode && bestValue > alpha)
alpha = bestValue;
- futilityBase = ss->eval + evalMargin + FutilityMarginQS;
- enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame;
+ futilityBase = ss->eval + evalMargin + Value(128);
+ enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMg;
}
// Initialize a MovePicker object for the current position, and prepare
// Loop through the moves until no moves remain or a beta cutoff occurs
while ( bestValue < beta
- && (move = mp.next_move()) != MOVE_NONE)
+ && (move = mp.next_move<false>()) != MOVE_NONE)
{
assert(is_ok(move));
&& !pos.is_passed_pawn_push(move))
{
futilityValue = futilityBase
- + PieceValueEndgame[pos.piece_on(to_sq(move))]
- + (type_of(move) == ENPASSANT ? PawnValueEndgame : VALUE_ZERO);
+ + PieceValue[Eg][pos.piece_on(to_sq(move))]
+ + (type_of(move) == ENPASSANT ? PawnValueEg : VALUE_ZERO);
if (futilityValue < beta)
{
&& givesCheck
&& move != ttMove
&& !pos.is_capture_or_promotion(move)
- && ss->eval + PawnValueMidgame / 4 < beta
+ && ss->eval + PawnValueMg / 4 < beta
&& !check_is_dangerous(pos, move, futilityBase, beta))
continue;
while (b)
{
// Note that here we generate illegal "double move"!
- if (futilityBase + PieceValueEndgame[pos.piece_on(pop_lsb(&b))] >= beta)
+ if (futilityBase + PieceValue[Eg][pos.piece_on(pop_lsb(&b))] >= beta)
return true;
}
// Case 2: If the threatened piece has value less than or equal to the
// value of the threatening piece, don't prune moves which defend it.
if ( pos.is_capture(threat)
- && ( PieceValueMidgame[pos.piece_on(tfrom)] >= PieceValueMidgame[pos.piece_on(tto)]
+ && ( PieceValue[Mg][pos.piece_on(tfrom)] >= PieceValue[Mg][pos.piece_on(tto)]
|| type_of(pos.piece_on(tfrom)) == KING)
&& pos.move_attacks_square(m, tto))
return true;
static RKISS rk;
// PRNG sequence should be not deterministic
- for (int i = Time::current_time().msec() % 50; i > 0; i--)
+ for (int i = Time::now() % 50; i > 0; i--)
rk.rand<unsigned>();
// RootMoves are already sorted by score in descending order
size_t size = std::min(MultiPV, RootMoves.size());
- int variance = std::min(RootMoves[0].score - RootMoves[size - 1].score, PawnValueMidgame);
+ int variance = std::min(RootMoves[0].score - RootMoves[size - 1].score, PawnValueMg);
int weakness = 120 - 2 * SkillLevel;
int max_s = -VALUE_INFINITE;
Move best = MOVE_NONE;
int s = RootMoves[i].score;
// Don't allow crazy blunders even at very low skills
- if (i > 0 && RootMoves[i-1].score > s + EasyMoveMargin)
+ if (i > 0 && RootMoves[i-1].score > s + 2 * PawnValueMg)
break;
// This is our magic formula
string uci_pv(const Position& pos, int depth, Value alpha, Value beta) {
std::stringstream s;
- int t = SearchTime.elapsed();
+ Time::point elaspsed = Time::now() - SearchTime + 1;
int selDepth = 0;
- for (int i = 0; i < Threads.size(); i++)
+ for (size_t i = 0; i < Threads.size(); i++)
if (Threads[i].maxPly > selDepth)
selDepth = Threads[i].maxPly;
s << "\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 " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0)
- << " time " << t
- << " multipv " << i + 1
+ << " seldepth " << selDepth
+ << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
+ << " nodes " << pos.nodes_searched()
+ << " nps " << pos.nodes_searched() * 1000 / elaspsed
+ << " time " << elaspsed
+ << " multipv " << i + 1
<< " pv";
for (size_t j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++)
}
-/// Thread::idle_loop() is where the thread is parked when it has no work to do.
-/// The parameter 'master_sp', if non-NULL, is a pointer to an active SplitPoint
-/// object for which the thread is the master.
+/// Thread::idle_loop() is where the thread is parked when it has no work to do
-void Thread::idle_loop(SplitPoint* sp_master) {
+void Thread::idle_loop() {
+
+ // Pointer 'sp_master', if non-NULL, points to the active SplitPoint
+ // object for which the thread is the master.
+ const SplitPoint* sp_master = splitPointsCnt ? curSplitPoint : NULL;
+
+ assert(!sp_master || (sp_master->master == this && is_searching));
// 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.
}
// Grab the lock to avoid races with Thread::wake_up()
- lock_grab(sleepLock);
+ mutex.lock();
// If we are master and all slaves have finished don't go to sleep
if (sp_master && !sp_master->slavesMask)
{
- lock_release(sleepLock);
+ mutex.unlock();
break;
}
// 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)
- cond_wait(sleepCond, sleepLock);
+ sleepCondition.wait(mutex);
- lock_release(sleepLock);
+ mutex.unlock();
}
// If this thread has been assigned work, launch a search
{
assert(!do_sleep && !do_exit);
- lock_grab(Threads.splitLock);
+ Threads.mutex.lock();
assert(is_searching);
SplitPoint* sp = curSplitPoint;
- lock_release(Threads.splitLock);
+ Threads.mutex.unlock();
Stack ss[MAX_PLY_PLUS_2];
Position pos(*sp->pos, this);
memcpy(ss, sp->ss - 1, 4 * sizeof(Stack));
(ss+1)->sp = sp;
- lock_grab(sp->lock);
+ sp->mutex.lock();
+
+ assert(sp->activePositions[idx] == NULL);
+
+ sp->activePositions[idx] = &pos;
if (sp->nodeType == Root)
search<SplitPointRoot>(pos, ss+1, sp->alpha, sp->beta, sp->depth);
assert(is_searching);
is_searching = false;
+ sp->activePositions[idx] = NULL;
sp->slavesMask &= ~(1ULL << idx);
sp->nodes += pos.nodes_searched();
// case we are the last slave of the split point.
if ( Threads.use_sleeping_threads()
&& this != sp->master
- && !sp->master->is_searching)
+ && !sp->slavesMask)
+ {
+ assert(!sp->master->is_searching);
sp->master->wake_up();
+ }
// After releasing the lock we cannot access anymore any SplitPoint
// related data in a safe way becuase it could have been released under
// our feet by the sp master. Also accessing other Thread objects is
// unsafe because if we are exiting there is a chance are already freed.
- lock_release(sp->lock);
+ sp->mutex.unlock();
}
}
}
void check_time() {
- static Time lastInfoTime = Time::current_time();
+ static Time::point lastInfoTime = Time::now();
+ int64_t nodes = 0; // Workaround silly 'uninitialized' gcc warning
- if (lastInfoTime.elapsed() >= 1000)
+ if (Time::now() - lastInfoTime >= 1000)
{
- lastInfoTime.restart();
+ lastInfoTime = Time::now();
dbg_print();
}
if (Limits.ponder)
return;
- int e = SearchTime.elapsed();
+ if (Limits.nodes)
+ {
+ Threads.mutex.lock();
+
+ nodes = RootPosition.nodes_searched();
+
+ // Loop across all split points and sum accumulated SplitPoint nodes plus
+ // all the currently active slaves positions.
+ for (size_t i = 0; i < Threads.size(); i++)
+ for (int j = 0; j < Threads[i].splitPointsCnt; j++)
+ {
+ SplitPoint& sp = Threads[i].splitPoints[j];
+
+ sp.mutex.lock();
+
+ nodes += sp.nodes;
+ Bitboard sm = sp.slavesMask;
+ while (sm)
+ {
+ Position* pos = sp.activePositions[pop_lsb(&sm)];
+ nodes += pos ? pos->nodes_searched() : 0;
+ }
+
+ sp.mutex.unlock();
+ }
+
+ Threads.mutex.unlock();
+ }
+
+ Time::point elapsed = Time::now() - SearchTime;
bool stillAtFirstMove = Signals.firstRootMove
&& !Signals.failedLowAtRoot
- && e > TimeMgr.available_time();
+ && elapsed > TimeMgr.available_time();
- bool noMoreTime = e > TimeMgr.maximum_time() - 2 * TimerResolution
+ bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerResolution
|| stillAtFirstMove;
if ( (Limits.use_time_management() && noMoreTime)
- || (Limits.movetime && e >= Limits.movetime))
+ || (Limits.movetime && elapsed >= Limits.movetime)
+ || (Limits.nodes && nodes >= Limits.nodes))
Signals.stop = true;
}
projects / stockfish / blobdiff