void idle_loop(int threadID, SplitPoint* sp);
template <bool Fake>
- void split(const Position& pos, SearchStack* ss, Value* alpha, const Value beta, Value* bestValue,
+ void split(const Position& pos, SearchStack* ss, int ply, Value* alpha, const Value beta, Value* bestValue,
Depth depth, bool mateThreat, int* moveCount, MovePicker* mp, bool pvNode);
private:
const Value EasyMoveMargin = Value(0x200);
// Last seconds noise filtering (LSN)
- const bool UseLSNFiltering = true;
- const int LSNTime = 4000; // In milliseconds
+ const bool UseLSNFiltering = false;
+ const int LSNTime = 100; // In milliseconds
const Value LSNValue = value_from_centipawns(200);
bool loseOnTime = false;
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);
+ Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply);
template <NodeType PvNode>
- Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth);
+ Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply);
template <NodeType PvNode>
void sp_search(SplitPoint* sp, int threadID);
// Init futility margins array
for (d = 0; d < 16; d++) for (mc = 0; mc < 64; mc++)
- FutilityMarginsMatrix[d][mc] = 112 * int(log(double(d * d) / 2) / log(2.0) + 1) - 8 * mc + 45;
+ FutilityMarginsMatrix[d][mc] = 112 * int(log(double(d * d) / 2) / log(2.0) + 1.001) - 8 * mc + 45;
// Init futility move count array
for (d = 0; d < 32; d++)
}
-// SearchStack::init() initializes a search stack. Used at the beginning of a
-// new search from the root.
+// SearchStack::init() initializes a search stack entry.
+// Called at the beginning of search() when starting to examine a new node.
void SearchStack::init() {
- pv[0] = pv[1] = MOVE_NONE;
+ pv[0] = pv[1] = bestMove = MOVE_NONE;
currentMove = threatMove = MOVE_NONE;
reduction = Depth(0);
eval = VALUE_NONE;
}
+// SearchStack::initKillers() initializes killers for a search stack entry
void SearchStack::initKillers() {
mateKiller = MOVE_NONE;
H.clear();
init_ss_array(ss, PLY_MAX_PLUS_2);
ValueByIteration[1] = rml.get_move_score(0);
- p.reset_ply();
Iteration = 1;
// Is one move significantly better than others after initial scoring ?
alpha = -VALUE_INFINITE;
// Full depth PV search, done on first move or after a fail high
- value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth);
+ value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, 1);
}
else
{
assert(newDepth-ss->reduction >= OnePly);
// Reduced depth non-pv search using alpha as upperbound
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, 1);
doFullDepthSearch = (value > alpha);
}
assert(newDepth - OnePly >= OnePly);
ss->reduction = OnePly;
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, 1);
doFullDepthSearch = (value > alpha);
}
ss->reduction = Depth(0); // Restore original reduction
if (doFullDepthSearch)
{
// Full depth non-pv search using alpha as upperbound
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth, 1);
// 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+1, -beta, -alpha, newDepth);
+ value = -search<PV>(pos, ss+1, -beta, -alpha, newDepth, 1);
}
}
// 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) {
+ Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) {
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta > alpha && beta <= VALUE_INFINITE);
assert(PvNode || alpha == beta - 1);
- assert(pos.ply() > 0 && pos.ply() < PLY_MAX);
+ assert(ply > 0 && ply < PLY_MAX);
assert(pos.thread() >= 0 && pos.thread() < TM.active_threads());
Move movesSearched[256];
bool mateThreat = false;
int moveCount = 0;
int threadID = pos.thread();
- int ply = pos.ply();
refinedValue = bestValue = value = -VALUE_INFINITE;
oldAlpha = alpha;
TT.store(posKey, ss->eval, VALUE_TYPE_EXACT, Depth(-127*OnePly), MOVE_NONE, ss->eval, ei.kingDanger[pos.side_to_move()]);
Value rbeta = beta - razor_margin(depth);
- Value v = qsearch<NonPV>(pos, ss, rbeta-1, rbeta, Depth(0));
+ Value v = qsearch<NonPV>(pos, ss, rbeta-1, rbeta, Depth(0), ply);
if (v < rbeta)
// Logically we should return (v + razor_margin(depth)), but
// surprisingly this did slightly weaker in tests.
pos.do_null_move(st);
(ss+1)->skipNullMove = true;
- nullValue = depth-R*OnePly < OnePly ? -qsearch<NonPV>(pos, ss+1, -beta, -alpha, Depth(0))
- : - search<NonPV>(pos, ss+1, -beta, -alpha, depth-R*OnePly);
+ nullValue = depth-R*OnePly < OnePly ? -qsearch<NonPV>(pos, ss+1, -beta, -alpha, Depth(0), ply+1)
+ : - search<NonPV>(pos, ss+1, -beta, -alpha, depth-R*OnePly, ply+1);
(ss+1)->skipNullMove = false;
pos.undo_null_move();
return nullValue;
ss->skipNullMove = true;
- Value v = search<NonPV>(pos, ss, alpha, beta, depth-5*OnePly);
+ Value v = search<NonPV>(pos, ss, alpha, beta, depth-5*OnePly, ply);
ss->skipNullMove = false;
if (v >= beta)
// Step 9. Internal iterative deepening
if ( depth >= IIDDepth[PvNode]
- && (ttMove == MOVE_NONE || (PvNode && tte->depth() <= depth - 4 * OnePly))
+ && ttMove == MOVE_NONE
&& (PvNode || (!isCheck && ss->eval >= beta - IIDMargin)))
{
Depth d = (PvNode ? depth - 2 * OnePly : depth / 2);
ss->skipNullMove = true;
- search<PvNode>(pos, ss, alpha, beta, d);
+ search<PvNode>(pos, ss, alpha, beta, d, ply);
ss->skipNullMove = false;
- ttMove = ss->pv[0];
+ ttMove = ss->bestMove;
tte = TT.retrieve(posKey);
}
Value b = ttValue - SingularExtensionMargin;
ss->excludedMove = move;
ss->skipNullMove = true;
- Value v = search<NonPV>(pos, ss, b - 1, b, depth / 2);
+ Value v = search<NonPV>(pos, ss, b - 1, b, depth / 2, ply);
ss->skipNullMove = false;
ss->excludedMove = MOVE_NONE;
-
if (v < ttValue - SingularExtensionMargin)
ext = OnePly;
}
// Step extra. pv search (only in PV nodes)
// The first move in list is the expected PV
if (PvNode && moveCount == 1)
- value = newDepth < OnePly ? -qsearch<PV>(pos, ss+1, -beta, -alpha, Depth(0))
- : - search<PV>(pos, ss+1, -beta, -alpha, newDepth);
+ value = newDepth < OnePly ? -qsearch<PV>(pos, ss+1, -beta, -alpha, Depth(0), ply+1)
+ : - search<PV>(pos, ss+1, -beta, -alpha, newDepth, ply+1);
else
{
// Step 14. Reduced depth search
if (ss->reduction)
{
Depth d = newDepth - ss->reduction;
- value = d < OnePly ? -qsearch<NonPV>(pos, ss+1, -(alpha+1), -alpha, Depth(0))
- : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d);
+ value = d < OnePly ? -qsearch<NonPV>(pos, ss+1, -(alpha+1), -alpha, Depth(0), ply+1)
+ : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, ply+1);
doFullDepthSearch = (value > alpha);
}
assert(newDepth - OnePly >= OnePly);
ss->reduction = OnePly;
- value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction);
+ value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth-ss->reduction, ply+1);
doFullDepthSearch = (value > alpha);
}
ss->reduction = Depth(0); // Restore original reduction
// Step 15. Full depth search
if (doFullDepthSearch)
{
- value = newDepth < OnePly ? -qsearch<NonPV>(pos, ss+1, -(alpha+1), -alpha, Depth(0))
- : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth);
+ value = newDepth < OnePly ? -qsearch<NonPV>(pos, ss+1, -(alpha+1), -alpha, Depth(0), ply+1)
+ : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, newDepth, ply+1);
// 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 = newDepth < OnePly ? -qsearch<PV>(pos, ss+1, -beta, -alpha, Depth(0))
- : - search<PV>(pos, ss+1, -beta, -alpha, newDepth);
+ value = newDepth < OnePly ? -qsearch<PV>(pos, ss+1, -beta, -alpha, Depth(0), ply+1)
+ : - search<PV>(pos, ss+1, -beta, -alpha, newDepth, ply+1);
}
}
&& !AbortSearch
&& !TM.thread_should_stop(threadID)
&& Iteration <= 99)
- TM.split<FakeSplit>(pos, ss, &alpha, beta, &bestValue, depth,
+ TM.split<FakeSplit>(pos, ss, ply, &alpha, beta, &bestValue, depth,
mateThreat, &moveCount, &mp, PvNode);
}
if (AbortSearch || TM.thread_should_stop(threadID))
return bestValue;
- if (bestValue <= oldAlpha)
- TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, depth, MOVE_NONE, ss->eval, ei.kingDanger[pos.side_to_move()]);
+ ValueType f = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT);
+ move = (bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove);
+ TT.store(posKey, value_to_tt(bestValue, ply), f, depth, move, ss->eval, ei.kingDanger[pos.side_to_move()]);
- else if (bestValue >= beta)
+ // Update killers and history only for non capture moves that fails high
+ if (bestValue >= beta)
{
TM.incrementBetaCounter(pos.side_to_move(), depth, threadID);
- move = ss->pv[0];
- 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);
}
}
- else
- TT.store(posKey, value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, depth, ss->pv[0], ss->eval, ei.kingDanger[pos.side_to_move()]);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
// less than OnePly).
template <NodeType PvNode>
- Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth) {
+ Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) {
assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
assert(PvNode || alpha == beta - 1);
assert(depth <= 0);
- assert(pos.ply() > 0 && pos.ply() < PLY_MAX);
+ assert(ply > 0 && ply < PLY_MAX);
assert(pos.thread() >= 0 && pos.thread() < TM.active_threads());
EvalInfo ei;
bool isCheck, deepChecks, enoughMaterial, moveIsCheck, evasionPrunable;
const TTEntry* tte;
Value oldAlpha = alpha;
- int ply = pos.ply();
TM.incrementNodeCounter(pos.thread());
- ss->pv[0] = ss->pv[1] = ss->currentMove = MOVE_NONE;
+ ss->pv[0] = ss->pv[1] = ss->bestMove = ss->currentMove = MOVE_NONE;
ss->eval = VALUE_NONE;
// Check for an instant draw or maximum ply reached
// Make and search the move
pos.do_move(move, st, ci, moveIsCheck);
- value = -qsearch<PvNode>(pos, ss+1, -beta, -alpha, depth-OnePly);
+ value = -qsearch<PvNode>(pos, ss+1, -beta, -alpha, depth-OnePly, ply+1);
pos.undo_move(move);
assert(value > -VALUE_INFINITE && value < VALUE_INFINITE);
// Update transposition table
Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1));
- if (bestValue <= oldAlpha)
- 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->pv[0];
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, move, ss->eval, ei.kingDanger[pos.side_to_move()]);
+ ValueType f = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), f, d, ss->bestMove, 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);
- }
- else
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EXACT, d, ss->pv[0], ss->eval, ei.kingDanger[pos.side_to_move()]);
+ // Update killers only for checking moves that fails high
+ if ( bestValue >= beta
+ && !pos.move_is_capture_or_promotion(ss->bestMove))
+ update_killers(ss->bestMove, ss);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
{
Value localAlpha = sp->alpha;
Depth d = newDepth - ss->reduction;
- value = d < OnePly ? -qsearch<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, Depth(0))
- : - search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, d);
+ value = d < OnePly ? -qsearch<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, Depth(0), sp->ply+1)
+ : - search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, d, sp->ply+1);
+
doFullDepthSearch = (value > localAlpha);
}
ss->reduction = OnePly;
Value localAlpha = sp->alpha;
- value = -search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth-ss->reduction);
+ value = -search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth-ss->reduction, sp->ply+1);
doFullDepthSearch = (value > localAlpha);
}
ss->reduction = Depth(0); // Restore original reduction
if (doFullDepthSearch)
{
Value localAlpha = sp->alpha;
- value = newDepth < OnePly ? -qsearch<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, Depth(0))
- : - search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth);
+ value = newDepth < OnePly ? -qsearch<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, Depth(0), sp->ply+1)
+ : - search<NonPV>(pos, ss+1, -(localAlpha+1), -localAlpha, newDepth, sp->ply+1);
// 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 > localAlpha && value < sp->beta)
- value = newDepth < OnePly ? -qsearch<PV>(pos, ss+1, -sp->beta, -sp->alpha, Depth(0))
- : - search<PV>(pos, ss+1, -sp->beta, -sp->alpha, newDepth);
+ value = newDepth < OnePly ? -qsearch<PV>(pos, ss+1, -sp->beta, -sp->alpha, Depth(0), sp->ply+1)
+ : - search<PV>(pos, ss+1, -sp->beta, -sp->alpha, newDepth, sp->ply+1);
}
// Step 16. Undo move
Move* src = (ss+1)->pv;
Move* dst = ss->pv;
- *dst = ss->currentMove;
+ *dst = ss->bestMove = ss->currentMove;
do
*++dst = *src;
Move* dst = ss->pv;
Move* pdst = pss->pv;
- *dst = *pdst = ss->currentMove;
+ *dst = *pdst = pss->bestMove = ss->bestMove = ss->currentMove;
do
*++dst = *++pdst = *src;
if (*dangerous)
{
- if (moveIsCheck)
+ if (moveIsCheck && pos.see_sign(m) >= 0)
result += CheckExtension[PvNode];
if (singleEvasion)
// 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, bool pvNode) {
+ void ThreadsManager::split(const Position& p, SearchStack* ss, int ply, Value* alpha,
+ const Value beta, Value* bestValue, Depth depth, bool mateThreat,
+ int* moveCount, MovePicker* mp, bool pvNode) {
assert(p.is_ok());
+ assert(ply > 0 && ply < PLY_MAX);
assert(*bestValue >= -VALUE_INFINITE);
assert(*bestValue <= *alpha);
assert(*alpha < beta);
// 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;
init_ss_array(ss, PLY_MAX_PLUS_2);
pos.do_move(cur->move, st);
moves[count].move = cur->move;
- moves[count].score = -qsearch<PV>(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, Depth(0));
+ moves[count].score = -qsearch<PV>(pos, ss+1, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1);
moves[count].pv[0] = cur->move;
moves[count].pv[1] = MOVE_NONE;
pos.undo_move(cur->move);
projects / stockfish / blobdiff