// Extensions. Configurable UCI options
// Array index 0 is used at non-PV nodes, index 1 at PV nodes.
- Depth CheckExtension[2], SingleEvasionExtension[2], PawnPushTo7thExtension[2];
- Depth PassedPawnExtension[2], PawnEndgameExtension[2], MateThreatExtension[2];
+ Depth CheckExtension[2], PawnPushTo7thExtension[2], PassedPawnExtension[2];
+ Depth PawnEndgameExtension[2], MateThreatExtension[2];
// Minimum depth for use of singular extension
const Depth SingularExtensionDepth[2] = { 8 * ONE_PLY /* non-PV */, 6 * ONE_PLY /* PV */};
template <NodeType PV>
inline Depth reduction(Depth d, int mn) { return (Depth) ReductionMatrix[PV][Min(d / 2, 63)][Min(mn, 63)]; }
- // Common adjustments
-
- // Search depth at iteration 1
- const Depth InitialDepth = ONE_PLY;
-
// Easy move margin. An easy move candidate must be at least this much
// better than the second best move.
const Value EasyMoveMargin = Value(0x200);
}
template <NodeType PvNode>
- Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool singleEvasion, bool mateThreat, bool* dangerous);
+ Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool mateThreat, bool* dangerous);
bool check_is_dangerous(Position &pos, Move move, Value futilityBase, Value beta, Value *bValue);
bool connected_moves(const Position& pos, Move m1, Move m2);
void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount);
void update_killers(Move m, Move killers[]);
void update_gains(const Position& pos, Move move, Value before, Value after);
+ void qsearch_scoring(Position& pos, MoveStack* mlist, MoveStack* last);
int current_search_time();
std::string value_to_uci(Value v);
return rm != Rml.end() ? rm->pv[0] : MOVE_NONE;
}
- int number_of_evasions() const { return (int)Rml.size(); }
RootMoveList::iterator rm;
bool firstCall;
CheckExtension[1] = Options["Check Extension (PV nodes)"].value<Depth>();
CheckExtension[0] = Options["Check Extension (non-PV nodes)"].value<Depth>();
- SingleEvasionExtension[1] = Options["Single Evasion Extension (PV nodes)"].value<Depth>();
- SingleEvasionExtension[0] = Options["Single Evasion Extension (non-PV nodes)"].value<Depth>();
PawnPushTo7thExtension[1] = Options["Pawn Push to 7th Extension (PV nodes)"].value<Depth>();
PawnPushTo7thExtension[0] = Options["Pawn Push to 7th Extension (non-PV nodes)"].value<Depth>();
PassedPawnExtension[1] = Options["Passed Pawn Extension (PV nodes)"].value<Depth>();
return MOVE_NONE;
}
- // Send initial scoring (iteration 1)
- cout << set960(pos.is_chess960()) // Is enough to set once at the beginning
- << "info depth " << iteration
- << "\n" << Rml[0].pv_info_to_uci(pos, ONE_PLY, alpha, beta) << endl;
-
// Is one move significantly better than others after initial scoring ?
if ( Rml.size() == 1
|| Rml[0].pv_score > Rml[1].pv_score + EasyMoveMargin)
easyMove = Rml[0].pv[0];
// Iterative deepening loop
- while (++iteration <= PLY_MAX && (!MaxDepth || iteration <= MaxDepth) && !StopRequest)
+ while (++iteration <= PLY_MAX && !StopRequest)
{
- cout << "info depth " << iteration << endl;
-
Rml.bestMoveChanges = researchCountFL = researchCountFH = 0;
- depth = (iteration - 2) * ONE_PLY + InitialDepth;
+ depth = (iteration - 1) * ONE_PLY;
+
+ if (MaxDepth && depth > MaxDepth * ONE_PLY)
+ break;
+
+ cout << "info depth " << depth / ONE_PLY << endl;
// Calculate dynamic aspiration window based on previous iterations
if (MultiPV == 1 && iteration >= 6 && abs(bestValues[iteration - 1]) < VALUE_KNOWN_WIN)
int prevDelta1 = bestValues[iteration - 1] - bestValues[iteration - 2];
int prevDelta2 = bestValues[iteration - 2] - bestValues[iteration - 3];
- aspirationDelta = Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16);
+ aspirationDelta = Min(Max(abs(prevDelta1) + abs(prevDelta2) / 2, 16), 24);
aspirationDelta = (aspirationDelta + 7) / 8 * 8; // Round to match grainSize
alpha = Max(bestValues[iteration - 1] - aspirationDelta, -VALUE_INFINITE);
// Search starting from ss+1 to allow calling update_gains()
value = search<PV, false, true>(pos, ss+1, alpha, beta, depth, 0);
- // Write PV lines to transposition table, in case the relevant entries
- // have been overwritten during the search.
+ // Send PV line to GUI and write to transposition table in case the
+ // relevant entries have been overwritten during the search.
for (int i = 0; i < Min(MultiPV, (int)Rml.size()); i++)
+ {
Rml[i].insert_pv_in_tt(pos);
+ cout << set960(pos.is_chess960())
+ << Rml[i].pv_info_to_uci(pos, depth, alpha, beta, i) << endl;
+ }
// Value cannot be trusted. Break out immediately!
if (StopRequest)
ValueType vt;
Value bestValue, value, oldAlpha;
Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific
- bool isPvMove, isCheck, singleEvasion, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous;
+ bool isPvMove, isCheck, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
int moveCount = 0, playedMoveCount = 0;
int threadID = pos.thread();
tte = TT.retrieve(posKey);
ttMove = tte ? tte->move() : MOVE_NONE;
- // At PV nodes, we don't use the TT for pruning, but only for move ordering.
- // This is to avoid problems in the following areas:
- //
- // * Repetition draw detection
- // * Fifty move rule detection
- // * Searching for a mate
- // * Printing of full PV line
- if (!PvNode && tte && ok_to_use_TT(tte, depth, beta, ply))
+ // At PV nodes we check for exact scores, while at non-PV nodes we check for
+ // and return a fail high/low. Biggest advantage at probing at PV nodes is
+ // to have a smooth experience in analysis mode.
+ if ( !Root
+ && tte
+ && (PvNode ? tte->depth() >= depth && tte->type() == VALUE_TYPE_EXACT
+ : ok_to_use_TT(tte, depth, beta, ply)))
{
TT.refresh(tte);
ss->bestMove = ttMove; // Can be MOVE_NONE
MovePickerExt<SpNode, Root> mp(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta));
CheckInfo ci(pos);
ss->bestMove = MOVE_NONE;
- singleEvasion = !SpNode && isCheck && mp.number_of_evasions() == 1;
futilityBase = ss->eval + ss->evalMargin;
singularExtensionNode = !Root
&& !SpNode
captureOrPromotion = pos.move_is_capture_or_promotion(move);
// Step 11. Decide the new search depth
- ext = extension<PvNode>(pos, move, captureOrPromotion, moveIsCheck, singleEvasion, mateThreat, &dangerous);
+ ext = extension<PvNode>(pos, move, captureOrPromotion, moveIsCheck, mateThreat, &dangerous);
// Singular extension search. If all moves but one fail low on a search of (alpha-s, beta-s),
// and just one fails high on (alpha, beta), then that move is singular and should be extended.
if (!isPvMove && MultiPV == 1)
Rml.bestMoveChanges++;
- // Inform GUI that PV has changed, in case of multi-pv UCI protocol
- // requires we send all the PV lines properly sorted.
Rml.sort_multipv(moveCount);
- for (int j = 0; j < Min(MultiPV, (int)Rml.size()); j++)
- cout << Rml[j].pv_info_to_uci(pos, depth, alpha, beta, j) << endl;
-
// Update alpha. In multi-pv we don't use aspiration window, so
// set alpha equal to minimum score among the PV lines.
if (MultiPV > 1)
}
+ // qsearch_scoring() scores each move of a list using a qsearch() evaluation,
+ // it is used in RootMoveList to get an initial scoring.
+ void qsearch_scoring(Position& pos, MoveStack* mlist, MoveStack* last) {
+
+ SearchStack ss[PLY_MAX_PLUS_2];
+ StateInfo st;
+
+ memset(ss, 0, 4 * sizeof(SearchStack));
+ ss[0].eval = ss[0].evalMargin = VALUE_NONE;
+
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ {
+ ss[0].currentMove = cur->move;
+ pos.do_move(cur->move, st);
+ cur->score = -qsearch<PV>(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, DEPTH_ZERO, 1);
+ pos.undo_move(cur->move);
+ }
+ }
+
+
// check_is_dangerous() tests if a checking move can be pruned in qsearch().
// bestValue is updated only when returning false because in that case move
// will be pruned.
// extended, as example because the corresponding UCI option is set to zero,
// the move is marked as 'dangerous' so, at least, we avoid to prune it.
template <NodeType PvNode>
- Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck,
- bool singleEvasion, bool mateThreat, bool* dangerous) {
+ Depth extension(const Position& pos, Move m, bool captureOrPromotion,
+ bool moveIsCheck, bool mateThreat, bool* dangerous) {
assert(m != MOVE_NONE);
Depth result = DEPTH_ZERO;
- *dangerous = moveIsCheck | singleEvasion | mateThreat;
+ *dangerous = moveIsCheck | mateThreat;
if (*dangerous)
{
if (moveIsCheck && pos.see_sign(m) >= 0)
result += CheckExtension[PvNode];
- if (singleEvasion)
- result += SingleEvasionExtension[PvNode];
-
if (mateThreat)
result += MateThreatExtension[PvNode];
}
void RootMoveList::init(Position& pos, Move searchMoves[]) {
- SearchStack ss[PLY_MAX_PLUS_2];
MoveStack mlist[MOVES_MAX];
- StateInfo st;
Move* sm;
- // Initialize search stack
- memset(ss, 0, PLY_MAX_PLUS_2 * sizeof(SearchStack));
- ss[0].eval = ss[0].evalMargin = VALUE_NONE;
- bestMoveChanges = 0;
clear();
+ bestMoveChanges = 0;
- // Generate all legal moves
+ // Generate all legal moves and score them
MoveStack* last = generate<MV_LEGAL>(pos, mlist);
+ qsearch_scoring(pos, mlist, last);
// Add each move to the RootMoveList's vector
for (MoveStack* cur = mlist; cur != last; cur++)
if (searchMoves[0] && *sm != cur->move)
continue;
- // Find a quick score for the move and add to the list
- pos.do_move(cur->move, st);
-
RootMove rm;
- rm.pv[0] = ss[0].currentMove = cur->move;
+ rm.pv[0] = cur->move;
rm.pv[1] = MOVE_NONE;
- rm.pv_score = -qsearch<PV>(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, DEPTH_ZERO, 1);
+ rm.pv_score = Value(cur->score);
push_back(rm);
-
- pos.undo_move(cur->move);
}
sort();
}
projects / stockfish / blobdiff