// If the TT move is at least SingleReplyMargin better then the
// remaining ones we will extend it.
- const Value SingleReplyMargin = Value(0x64);
+ const Value SingleReplyMargin = Value(0x20);
// Margins for futility pruning in the quiescence search, and at frontier
// and near frontier nodes.
const Value FutilityMarginQS = Value(0x80);
// Each move futility margin is decreased
- const Value IncrementalFutilityMargin = Value(0x4);
+ const Value IncrementalFutilityMargin = Value(0x8);
- // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply
- const Value FutilityMargins[12] = { Value(0x100), Value(0x120), Value(0x200), Value(0x220), Value(0x250), Value(0x270),
- // 4 ply 4.5 ply 5 ply 5.5 ply 6 ply 6.5 ply
- Value(0x2A0), Value(0x2C0), Value(0x340), Value(0x360), Value(0x3A0), Value(0x3C0) };
// Razoring
const Depth RazorDepth = 4*OnePly;
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);
Problem = false;
ExactMaxTime = maxTime;
+ if (button_was_pressed("New Game"))
+ loseOnTime = false; // reset at the beginning of a new game
+
// Read UCI option values
TT.set_size(get_option_value_int("Hash"));
if (button_was_pressed("Clear Hash"))
- {
TT.clear();
- loseOnTime = false; // reset at the beginning of a new game
- }
bool PonderingEnabled = get_option_value_bool("Ponder");
MultiPV = get_option_value_int("MultiPV");
// searchMoves are verified, copied, scored and sorted
RootMoveList rml(p, searchMoves);
+ if (rml.move_count() == 0)
+ {
+ if (PonderSearch)
+ wait_for_stop_or_ponderhit();
+
+ return pos.is_check()? -VALUE_MATE : VALUE_DRAW;
+ }
+
// Print RootMoveList c'tor startup scoring to the standard output,
// so that we print information also for iteration 1.
std::cout << "info depth " << 1 << "\ninfo depth " << 1
if (tte && ok_to_use_TT(tte, depth, beta, ply))
{
- ss[ply].currentMove = ttMove; // can be MOVE_NONE
+ ss[ply].currentMove = ttMove; // Can be MOVE_NONE
return value_from_tt(tte->value(), ply);
}
futilityValue = VALUE_NONE;
useFutilityPruning = depth < SelectiveDepth && !isCheck;
+ // Calculate depth dependant futility pruning parameters
+ const int FutilityMoveCountMargin = 3 + (1 << (3 * int(depth) / 8));
+ const int FutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2);
+
// Avoid calling evaluate() if we already have the score in TT
if (tte && (tte->type() & VALUE_TYPE_EVAL))
- futilityValue = value_from_tt(tte->value(), ply) + FutilityMargins[int(depth) - 2];
-
- // Move count pruning limit
- const int MCLimit = 3 + (1 << (3*int(depth)/8));
-
- /*
- for (int d = 2; d < 16; d++)
- std::cout << d << " -> " << 56*(0+2*bitScanReverse32(1 * int(d) * int(d) / 2)) << std::endl;
- //std::cout << d << " -> " << 32*(1+3*bitScanReverse32(1 * int(d) * int(d))) << std::endl;
- */
+ futilityValue = value_from_tt(tte->value(), ply) + FutilityValueMargin;
// Loop through all legal moves until no moves remain or a beta cutoff occurs
while ( bestValue < beta
&& !captureOrPromotion
&& move != ttMove)
{
- // History pruning. See ok_to_prune() definition
- if ( moveCount >= MCLimit
- && ok_to_prune(pos, move, ss[ply].threatMove, depth)
+ // Move count based pruning
+ if ( moveCount >= FutilityMoveCountMargin
+ && ok_to_prune(pos, move, ss[ply].threatMove)
&& bestValue > value_mated_in(PLY_MAX))
continue;
// Value based pruning
- if (approximateEval < beta)
- {//dbg_before();
- if (futilityValue == VALUE_NONE)
- futilityValue = evaluate(pos, ei, threadID)
- + 56*(0+2*bitScanReverse32(1 * int(depth) * int(depth) / 2));
+ if (futilityValue == VALUE_NONE)
+ futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin;
- futilityValueScaled = futilityValue - moveCount * IncrementalFutilityMargin;
+ futilityValueScaled = futilityValue - moveCount * IncrementalFutilityMargin;
- if (futilityValueScaled < beta)
- {
- if (futilityValueScaled > bestValue)
- bestValue = futilityValueScaled;
- continue;
- }
- //dbg_after(); // 36% (inc == 8), 40% (inc == 4), 37%(56)
+ if (futilityValueScaled < beta)
+ {
+ if (futilityValueScaled > bestValue)
+ bestValue = futilityValueScaled;
+ continue;
}
}
value = -search(pos, ss, -(beta-1), newDepth-OnePly, ply+1, true, threadID);
}
else
- value = beta; // Just to trigger next condition
+ value = beta; // Just to trigger next condition
if (value >= beta) // Go with full depth non-pv search
{
// New best move?
if (value > bestValue)
{
- bestValue = value;
- if (value >= beta)
- update_pv(ss, ply);
+ bestValue = value;
+ if (value >= beta)
+ update_pv(ss, ply);
- if (value == value_mate_in(ply + 1))
- ss[ply].mateKiller = move;
+ if (value == value_mate_in(ply + 1))
+ ss[ply].mateKiller = move;
}
// Split?
&& !thread_should_stop(threadID)
&& split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue, approximateEval,
depth, &moveCount, &mp, threadID, false))
- break;
+ break;
}
// All legal moves have been searched. A special case: If there were
}
ttMove = (tte ? tte->move() : MOVE_NONE);
- // Evaluate the position statically
isCheck = pos.is_check();
ei.futilityMargin = Value(0); // Manually initialize futilityMargin
+ // Evaluate the position statically
if (isCheck)
staticValue = -VALUE_INFINITE;
// Use the cached evaluation score if possible
assert(ei.futilityMargin == Value(0));
- staticValue = tte->value();
+ staticValue = value_from_tt(tte->value(), ply);
}
else
staticValue = evaluate(pos, ei, threadID);
bool useFutilityPruning = sp->depth < SelectiveDepth
&& !isCheck;
+ const int FutilityValueMargin = 112 * bitScanReverse32(int(sp->depth) * int(sp->depth) / 2);
+
while ( sp->bestValue < sp->beta
&& !thread_should_stop(threadID)
&& (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE)
&& !dangerous
&& !captureOrPromotion)
{
- // History pruning. See ok_to_prune() definition
+ // Move count based pruning
if ( moveCount >= 2 + int(sp->depth)
- && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth)
+ && ok_to_prune(pos, move, ss[sp->ply].threatMove)
&& sp->bestValue > value_mated_in(PLY_MAX))
continue;
if (sp->futilityValue == VALUE_NONE)
{
EvalInfo ei;
- sp->futilityValue = evaluate(pos, ei, threadID)
- + FutilityMargins[int(sp->depth) - 2];
+ sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin;
}
if (sp->futilityValue < sp->beta)
// 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));
&& 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
Value v = value_from_tt(tte->value(), ply);
return ( tte->depth() >= depth
- || v >= Max(value_mate_in(100), beta)
- || v < Min(value_mated_in(100), beta))
+ || v >= Max(value_mate_in(PLY_MAX), beta)
+ || v < Min(value_mated_in(PLY_MAX), beta))
&& ( (is_lower_bound(tte->type()) && v >= beta)
|| (is_upper_bound(tte->type()) && v < beta));
{
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