namespace {
- // Maximum number of allowed moves per position
- const int MOVES_MAX = 256;
-
// Types
enum NodeType { NonPV, PV };
// Dynamic razoring margin based on depth
inline Value razor_margin(Depth d) { return Value(0x200 + 0x10 * int(d)); }
- // Step 8. Null move search with verification search
-
- // Null move margin. A null move search will not be done if the static
- // evaluation of the position is more than NullMoveMargin below beta.
- const Value NullMoveMargin = Value(0x200);
-
// Maximum depth for use of dynamic threat detection when null move fails low
const Depth ThreatDepth = 5 * ONE_PLY;
const Value FutilityMarginQS = Value(0x80);
// Futility lookup tables (initialized at startup) and their getter functions
- int32_t FutilityMarginsMatrix[16][64]; // [depth][moveNumber]
+ Value FutilityMarginsMatrix[16][64]; // [depth][moveNumber]
int FutilityMoveCountArray[32]; // [depth]
- inline Value futility_margin(Depth d, int mn) { return Value(d < 7 * ONE_PLY ? FutilityMarginsMatrix[Max(d, 1)][Min(mn, 63)] : 2 * VALUE_INFINITE); }
+ inline Value futility_margin(Depth d, int mn) { return d < 7 * ONE_PLY ? FutilityMarginsMatrix[Max(d, 1)][Min(mn, 63)] : 2 * VALUE_INFINITE; }
inline int futility_move_count(Depth d) { return d < 16 * ONE_PLY ? FutilityMoveCountArray[d] : 512; }
// Step 14. Reduced search
// Init futility margins array
for (d = 1; d < 16; d++) for (mc = 0; mc < 64; mc++)
- FutilityMarginsMatrix[d][mc] = 112 * int(log(double(d * d) / 2) / log(2.0) + 1.001) - 8 * mc + 45;
+ FutilityMarginsMatrix[d][mc] = Value(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++)
- FutilityMoveCountArray[d] = 3 + (1 << (3 * d / 8));
+ FutilityMoveCountArray[d] = int(3.001 + 0.25 * pow(d, 2.0));
}
// Add some extra time if the best move has changed during the last two iterations
if (Iteration > 5 && Iteration <= 50)
- TimeMgr.pv_unstability(BestMoveChangesByIteration[Iteration],
+ TimeMgr.pv_instability(BestMoveChangesByIteration[Iteration],
BestMoveChangesByIteration[Iteration-1]);
// Stop search if most of MaxSearchTime is consumed at the end of the
Value root_search(Position& pos, SearchStack* ss, Move* pv, RootMoveList& rml, Value* alphaPtr, Value* betaPtr) {
- Value margins[2];
StateInfo st;
CheckInfo ci(pos);
int64_t nodes;
Move move;
Depth depth, ext, newDepth;
- Value value, alpha, beta;
+ Value value, evalMargin, alpha, beta;
bool isCheck, moveIsCheck, captureOrPromotion, dangerous;
int researchCountFH, researchCountFL;
// Step 5. Evaluate the position statically
// At root we do this only to get reference value for child nodes
- ss->eval = isCheck ? VALUE_NONE : evaluate(pos, margins);
+ ss->eval = isCheck ? VALUE_NONE : evaluate(pos, evalMargin);
// Step 6. Razoring (omitted at root)
// Step 7. Static null move pruning (omitted at root)
assert(pos.thread() >= 0 && pos.thread() < ThreadsMgr.active_threads());
Move movesSearched[MOVES_MAX];
- Value margins[2];
StateInfo st;
const TTEntry *tte;
Key posKey;
Move ttMove, move, excludedMove, threatMove;
Depth ext, newDepth;
- Value bestValue, value, oldAlpha;
+ Value bestValue, value, evalMargin, oldAlpha;
Value refinedValue, nullValue, futilityBase, futilityValueScaled; // Non-PV specific
bool isCheck, singleEvasion, singularExtensionNode, moveIsCheck, captureOrPromotion, dangerous;
bool mateThreat = false;
// Step 2. Check for aborted search and immediate draw
if (AbortSearch || ThreadsMgr.thread_should_stop(threadID))
- return VALUE_ZERO;
+ return VALUE_DRAW;
if (pos.is_draw() || ply >= PLY_MAX - 1)
return VALUE_DRAW;
// update gain statistics of parent move.
isCheck = pos.is_check();
if (isCheck)
- ss->eval = VALUE_NONE;
+ ss->eval = evalMargin = VALUE_NONE;
else if (tte)
{
assert(tte->static_value() != VALUE_NONE);
ss->eval = tte->static_value();
- margins[pos.side_to_move()] = tte->static_value_margin();
+ evalMargin = tte->static_value_margin();
refinedValue = refine_eval(tte, ss->eval, ply);
}
else
{
- refinedValue = ss->eval = evaluate(pos, margins);
- TT.store(posKey, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, MOVE_NONE, ss->eval, margins[pos.side_to_move()]);
+ refinedValue = ss->eval = evaluate(pos, evalMargin);
+ TT.store(posKey, VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
}
// Save gain for the parent non-capture move
return refinedValue - futility_margin(depth, 0);
// Step 8. Null move search with verification search (is omitted in PV nodes)
- // When we jump directly to qsearch() we do a null move only if static value is
- // at least beta. Otherwise we do a null move if static value is not more than
- // NullMoveMargin under beta.
if ( !PvNode
&& !ss->skipNullMove
&& depth > ONE_PLY
&& !isCheck
- && refinedValue >= beta - (depth >= 4 * ONE_PLY ? NullMoveMargin : 0)
+ && refinedValue >= beta
&& !value_is_mate(beta)
&& pos.non_pawn_material(pos.side_to_move()))
{
CheckInfo ci(pos);
ss->bestMove = MOVE_NONE;
singleEvasion = isCheck && mp.number_of_evasions() == 1;
- futilityBase = ss->eval + margins[pos.side_to_move()];
+ futilityBase = ss->eval + evalMargin;
singularExtensionNode = depth >= SingularExtensionDepth[PvNode]
&& tte
&& tte->move()
ValueType vt = (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), vt, depth, move, ss->eval, margins[pos.side_to_move()]);
+ TT.store(posKey, value_to_tt(bestValue, ply), vt, depth, move, ss->eval, evalMargin);
// Update killers and history only for non capture moves that fails high
if ( bestValue >= beta
assert(ply > 0 && ply < PLY_MAX);
assert(pos.thread() >= 0 && pos.thread() < ThreadsMgr.active_threads());
- Value margins[2];
StateInfo st;
Move ttMove, move;
- Value bestValue, value, futilityValue, futilityBase;
+ Value bestValue, value, evalMargin, futilityValue, futilityBase;
bool isCheck, deepChecks, enoughMaterial, moveIsCheck, evasionPrunable;
const TTEntry* tte;
Value oldAlpha = alpha;
if (isCheck)
{
bestValue = futilityBase = -VALUE_INFINITE;
- ss->eval = VALUE_NONE;
+ ss->eval = evalMargin = VALUE_NONE;
deepChecks = enoughMaterial = false;
}
else
{
assert(tte->static_value() != VALUE_NONE);
- margins[pos.side_to_move()] = tte->static_value_margin();
- bestValue = tte->static_value();
+ evalMargin = tte->static_value_margin();
+ ss->eval = bestValue = tte->static_value();
}
else
- bestValue = evaluate(pos, margins);
+ ss->eval = bestValue = evaluate(pos, evalMargin);
- ss->eval = bestValue;
update_gains(pos, (ss-1)->currentMove, (ss-1)->eval, ss->eval);
// Stand pat. Return immediately if static value is at least beta
if (bestValue >= beta)
{
if (!tte)
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, margins[pos.side_to_move()]);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
return bestValue;
}
deepChecks = (depth == -ONE_PLY && bestValue >= beta - PawnValueMidgame / 8);
// Futility pruning parameters, not needed when in check
- futilityBase = bestValue + FutilityMarginQS + margins[pos.side_to_move()];
+ futilityBase = ss->eval + evalMargin + FutilityMarginQS;
enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame;
}
}
}
- // Detect blocking evasions that are candidate to be pruned
+ // Detect non-capture evasions that are candidate to be pruned
evasionPrunable = isCheck
&& bestValue > value_mated_in(PLY_MAX)
&& !pos.move_is_capture(move)
- && pos.type_of_piece_on(move_from(move)) != KING
&& !pos.can_castle(pos.side_to_move());
// Don't search moves with negative SEE values
// Update transposition table
Depth d = (depth == DEPTH_ZERO ? DEPTH_ZERO : DEPTH_ZERO - ONE_PLY);
ValueType vt = (bestValue <= oldAlpha ? VALUE_TYPE_UPPER : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT);
- TT.store(pos.get_key(), value_to_tt(bestValue, ply), vt, d, ss->bestMove, ss->eval, margins[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);
+ TT.store(pos.get_key(), value_to_tt(bestValue, ply), vt, d, ss->bestMove, ss->eval, evalMargin);
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
if (value > sp->bestValue && !ThreadsMgr.thread_should_stop(threadID))
{
sp->bestValue = value;
-
- if (sp->bestValue > sp->alpha)
+ if (value > sp->alpha)
{
if (!PvNode || value >= sp->beta)
sp->stopRequest = true;
- if (PvNode && value < sp->beta) // This guarantees that always: sp->alpha < sp->beta
+ if (PvNode && value < sp->beta) // We want always sp->alpha < sp->beta
sp->alpha = value;
sp->parentSstack->bestMove = ss->bestMove = move;
StateInfo st;
TTEntry* tte;
Position p(pos, pos.thread());
- Value margins[2];
- Value v;
+ Value v, m = VALUE_NONE;
for (int i = 0; pv[i] != MOVE_NONE; i++)
{
tte = TT.retrieve(p.get_key());
if (!tte || tte->move() != pv[i])
{
- v = (p.is_check() ? VALUE_NONE : evaluate(p, margins));
- TT.store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, pv[i], v, margins[pos.side_to_move()]);
+ v = (p.is_check() ? VALUE_NONE : evaluate(p, m));
+ TT.store(p.get_key(), VALUE_NONE, VALUE_TYPE_NONE, DEPTH_NONE, pv[i], v, m);
}
p.do_move(pv[i], st);
}
lock_grab(&(sp->lock));
lock_release(&(sp->lock));
+ // In helpful master concept a master can help only a sub-tree, and
+ // because here is all finished is not possible master is booked.
assert(threads[threadID].state == THREAD_AVAILABLE);
threads[threadID].state = THREAD_SEARCHING;
void ThreadsManager::exit_threads() {
- ActiveThreads = MAX_THREADS; // HACK
- AllThreadsShouldSleep = true; // HACK
+ ActiveThreads = MAX_THREADS; // Wake up all the threads
+ AllThreadsShouldExit = true; // Let the woken up threads to exit idle_loop()
+ AllThreadsShouldSleep = true; // Avoid an assert in wake_sleeping_threads()
wake_sleeping_threads();
- // This makes the threads to exit idle_loop()
- AllThreadsShouldExit = true;
-
// Wait for thread termination
for (int i = 1; i < MAX_THREADS; i++)
while (threads[i].state != THREAD_TERMINATED) {}
assert(threadID >= 0 && threadID < ActiveThreads);
- SplitPoint* sp;
+ SplitPoint* sp = threads[threadID].splitPoint;
- for (sp = threads[threadID].splitPoint; sp && !sp->stopRequest; sp = sp->parent) {}
+ for ( ; sp && !sp->stopRequest; sp = sp->parent) {}
return sp != NULL;
}
// Make a local copy to be sure doesn't change under our feet
int localActiveSplitPoints = threads[slave].activeSplitPoints;
- if (localActiveSplitPoints == 0)
- // No active split points means that the thread is available as
- // a slave for any other thread.
- return true;
-
- if (ActiveThreads == 2)
+ // No active split points means that the thread is available as
+ // a slave for any other thread.
+ if (localActiveSplitPoints == 0 || ActiveThreads == 2)
return true;
// Apply the "helpful master" concept if possible. Use localActiveSplitPoints
projects / stockfish / blobdiff