// Use internal iterative deepening?
const bool UseIIDAtPVNodes = true;
- const bool UseIIDAtNonPVNodes = false;
+ const bool UseIIDAtNonPVNodes = true;
// Internal iterative deepening margin. At Non-PV moves, when
// UseIIDAtNonPVNodes is true, we do an internal iterative deepening
Depth ThreatDepth; // heavy SMP read access
// Last seconds noise filtering (LSN)
- const bool UseLSNFiltering = true;
+ const bool UseLSNFiltering = false;
const int LSNTime = 4000; // In milliseconds
const Value LSNValue = value_from_centipawns(200);
bool loseOnTime = false;
bool move_is_killer(Move m, const SearchStack& ss);
Depth extension(const Position& pos, Move m, bool pvNode, bool capture, bool check, bool singleReply, bool mateThreat, bool* dangerous);
bool ok_to_do_nullmove(const Position& pos);
- bool ok_to_prune(const Position& pos, Move m, Move threat, Depth d);
+ bool ok_to_prune(const Position& pos, Move m, Move threat);
bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply);
void update_history(const Position& pos, Move m, Depth depth, Move movesSearched[], int moveCount);
void update_killers(Move m, SearchStack& ss);
{
Move bookMove;
if (get_option_value_string("Book File") != OpeningBook.file_name())
- OpeningBook.open("book.bin");
+ OpeningBook.open(get_option_value_string("Book File"));
bookMove = OpeningBook.get_move(pos);
if (bookMove != MOVE_NONE)
// Write PV to transposition table, in case the relevant entries have
// been overwritten during the search.
- //TT.insert_pv(p, ss[0].pv);
+ TT.insert_pv(p, ss[0].pv);
if (AbortSearch)
break; // Value cannot be trusted. Break out immediately!
search_pv(pos, ss, alpha, beta, depth-2*OnePly, ply, threadID);
ttMove = ss[ply].pv[ply];
tte = TT.retrieve(pos.get_key());
-
- // If tte->move() != MOVE_NONE then it equals ttMove
- assert(!(tte && tte->move()) || tte->move() == ttMove);
}
// Initialize a MovePicker object for the current position, and prepare
// Go with internal iterative deepening if we don't have a TT move
if (UseIIDAtNonPVNodes && ttMove == MOVE_NONE && depth >= 8*OnePly &&
- evaluate(pos, ei, threadID) >= beta - IIDMargin)
+ !isCheck && evaluate(pos, ei, threadID) >= beta - IIDMargin)
{
search(pos, ss, beta, Min(depth/2, depth-2*OnePly), ply, false, threadID);
ttMove = ss[ply].pv[ply];
&& !captureOrPromotion
&& move != ttMove)
{
- // History pruning. See ok_to_prune() definition
+ // Move count based pruning
if ( moveCount >= FutilityMoveCountMargin
- && ok_to_prune(pos, move, ss[ply].threatMove, depth)
+ && ok_to_prune(pos, move, ss[ply].threatMove)
&& bestValue > value_mated_in(PLY_MAX))
continue;
bool useFutilityPruning = sp->depth < SelectiveDepth
&& !isCheck;
+ const int FutilityMoveCountMargin = 3 + (1 << (3 * int(sp->depth) / 8));
const int FutilityValueMargin = 112 * bitScanReverse32(int(sp->depth) * int(sp->depth) / 2);
while ( sp->bestValue < sp->beta
&& !dangerous
&& !captureOrPromotion)
{
- // History pruning. See ok_to_prune() definition
- if ( moveCount >= 2 + int(sp->depth)
- && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth)
+ // Move count based pruning
+ if ( moveCount >= FutilityMoveCountMargin
+ && ok_to_prune(pos, move, ss[sp->ply].threatMove)
&& sp->bestValue > value_mated_in(PLY_MAX))
continue;
// Value based pruning
- if (sp->approximateEval < sp->beta)
+ if (sp->futilityValue == VALUE_NONE)
{
- if (sp->futilityValue == VALUE_NONE)
- {
- EvalInfo ei;
- sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin;
- }
+ EvalInfo ei;
+ sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin;
+ }
- if (sp->futilityValue < sp->beta)
+ Value futilityValueScaled = sp->futilityValue - moveCount * IncrementalFutilityMargin;
+
+ if (futilityValueScaled < sp->beta)
+ {
+ if (futilityValueScaled > sp->bestValue) // Less then 1% of cases
{
- if (sp->futilityValue > sp->bestValue) // Less then 1% of cases
- {
- lock_grab(&(sp->lock));
- if (sp->futilityValue > sp->bestValue)
- sp->bestValue = sp->futilityValue;
- lock_release(&(sp->lock));
- }
- continue;
+ lock_grab(&(sp->lock));
+ if (futilityValueScaled > sp->bestValue)
+ sp->bestValue = futilityValueScaled;
+ lock_release(&(sp->lock));
}
+ continue;
}
}
// non-tactical moves late in the move list close to the leaves are
// candidates for pruning.
- bool ok_to_prune(const Position& pos, Move m, Move threat, Depth d) {
+ bool ok_to_prune(const Position& pos, Move m, Move threat) {
assert(move_is_ok(m));
assert(threat == MOVE_NONE || move_is_ok(threat));
assert(!pos.move_is_check(m));
assert(!pos.move_is_capture_or_promotion(m));
assert(!pos.move_is_passed_pawn_push(m));
- assert(d >= OnePly);
Square mfrom, mto, tfrom, tto;
&& pos.move_attacks_square(m, tto))
return false;
- // Case 4: Don't prune moves with good history
- if (!H.ok_to_prune(pos.piece_on(mfrom), mto, d))
- return false;
-
- // Case 5: If the moving piece in the threatened move is a slider, don't
+ // Case 4: If the moving piece in the threatened move is a slider, don't
// prune safe moves which block its ray.
if ( !PruneBlockingMoves
&& threat != MOVE_NONE
{
assert(m != movesSearched[i]);
if (!pos.move_is_capture_or_promotion(movesSearched[i]))
- H.failure(pos.piece_on(move_from(movesSearched[i])), move_to(movesSearched[i]));
+ H.failure(pos.piece_on(move_from(movesSearched[i])), move_to(movesSearched[i]), depth);
}
}
projects / stockfish / blobdiff