// evaluation of the position is more than NullMoveMargin below beta.
const Value NullMoveMargin = Value(0x300);
+ //Null move search refutes move when Nullvalue >= Beta - Delta. Index is depth
+ //in full plies. Last index is 9+.
+ const Value NullMoveDeltaMidgame[] =
+ { Value(-8), Value( 6), Value(-15), Value( 9), Value(21),
+ Value(34), Value(54), Value( 59), Value(61), Value(61) };
+
+ const Value NullMoveDeltaEndgame[] =
+ { Value( 6), Value( 0), Value(-13), Value(-9), Value(-35),
+ Value(12), Value(24), Value( 9), Value( 5), Value( 5) };
+
// Pruning criterions. See the code and comments in ok_to_prune() to
// understand their precise meaning.
const bool PruneEscapeMoves = false;
Depth depth, int ply, int threadID);
void sp_search(SplitPoint *sp, int threadID);
void sp_search_pv(SplitPoint *sp, int threadID);
- void init_search_stack(SearchStack& ss);
- void init_search_stack(SearchStack ss[]);
void init_node(const Position &pos, SearchStack ss[], int ply, int threadID);
void update_pv(SearchStack ss[], int ply);
void sp_update_pv(SearchStack *pss, SearchStack ss[], int ply);
bool thread_is_available(int slave, int master);
bool idle_thread_exists(int master);
bool split(const Position &pos, SearchStack *ss, int ply,
- Value *alpha, Value *beta, Value *bestValue, Depth depth,
- int *moves, MovePicker *mp, int master, bool pvNode);
+ Value *alpha, Value *beta, Value *bestValue, Depth depth, int *moves,
+ MovePicker *mp, Bitboard dcCandidates, int master, bool pvNode);
void wake_sleeping_threads();
#if !defined(_MSC_VER)
SearchStack EmptySearchStack;
+// SearchStack::init() initializes a search stack. Used at the beginning of a
+// new search from the root.
+void SearchStack::init(int ply) {
+
+ pv[ply] = pv[ply + 1] = MOVE_NONE;
+ currentMove = threatMove = MOVE_NONE;
+ reduction = Depth(0);
+ currentMoveCaptureValue = Value(0);
+}
+
+void SearchStack::initKillers() {
+
+ mateKiller = MOVE_NONE;
+ for (int i = 0; i < KILLER_MAX; i++)
+ killers[i] = MOVE_NONE;
+}
+
+
////
//// Functions
////
}
// Init also the empty search stack
- init_search_stack(EmptySearchStack);
+ EmptySearchStack.init(0);
+ EmptySearchStack.initKillers();
}
// Initialize
TT.new_search();
H.clear();
- init_search_stack(ss);
-
+ for (int i = 0; i < 3; i++)
+ {
+ ss[i].init(i);
+ ss[i].initKillers();
+ }
ValueByIteration[0] = Value(0);
ValueByIteration[1] = rml.get_move_score(0);
Iteration = 1;
if (dbg_show_hit_rate)
dbg_print_hit_rate(LogFile);
- UndoInfo u;
+ StateInfo st;
LogFile << "Nodes: " << nodes_searched() << std::endl
<< "Nodes/second: " << nps() << std::endl
<< "Best move: " << move_to_san(p, ss[0].pv[0]) << std::endl;
- p.do_move(ss[0].pv[0], u);
+ p.do_move(ss[0].pv[0], st);
LogFile << "Ponder move: " << move_to_san(p, ss[0].pv[1])
<< std::endl << std::endl;
}
Value alpha = -VALUE_INFINITE;
Value beta = VALUE_INFINITE, value;
+ Bitboard dcCandidates = pos.discovered_check_candidates(pos.side_to_move());
// Loop through all the moves in the root move list
for (int i = 0; i < rml.move_count() && !AbortSearch; i++)
{
int64_t nodes;
Move move;
- UndoInfo u;
+ StateInfo st;
Depth ext, newDepth;
RootMoveNumber = i + 1;
newDepth = (Iteration - 2) * OnePly + ext + InitialDepth;
// Make the move, and search it
- pos.do_move(move, u);
+ pos.do_move(move, st, dcCandidates);
if (i < MultiPV)
{
Move move, movesSearched[256];
int moveCount = 0;
Value value, bestValue = -VALUE_INFINITE;
+ Bitboard dcCandidates = mp.discovered_check_candidates();
Color us = pos.side_to_move();
bool isCheck = pos.is_check();
bool mateThreat = pos.has_mate_threat(opposite_color(us));
assert(move_is_ok(move));
bool singleReply = (isCheck && mp.number_of_moves() == 1);
- bool moveIsCheck = pos.move_is_check(move);
+ bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
movesSearched[moveCount++] = ss[ply].currentMove = move;
Depth newDepth = depth - OnePly + ext;
// Make and search the move
- UndoInfo u;
- pos.do_move(move, u);
+ StateInfo st;
+ pos.do_move(move, st, dcCandidates);
if (moveCount == 1) // The first move in list is the PV
value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID);
&& !AbortSearch
&& !thread_should_stop(threadID)
&& split(pos, ss, ply, &alpha, &beta, &bestValue, depth,
- &moveCount, &mp, threadID, true))
+ &moveCount, &mp, dcCandidates, threadID, true))
break;
}
&& ok_to_do_nullmove(pos)
&& approximateEval >= beta - NullMoveMargin)
{
+ //Calculate correct delta. Idea and tuning from Joona Kiiski.
+ ScaleFactor factor[2] = { SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL };
+ Phase phase = pos.game_phase();
+ int i = Min(depth / OnePly, 9);
+ Value delta = scale_by_game_phase(NullMoveDeltaMidgame[i], NullMoveDeltaEndgame[i], phase, factor);
+
ss[ply].currentMove = MOVE_NULL;
- UndoInfo u;
- pos.do_null_move(u);
+ StateInfo st;
+ pos.do_null_move(st);
int R = (depth >= 4 * OnePly ? 4 : 3); // Null move dynamic reduction
- Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
+ Value nullValue = -search(pos, ss, -(beta-delta-1), depth-R*OnePly, ply+1, false, threadID);
// Check for a null capture artifact, if the value without the null capture
// is above beta then mark the node as a suspicious failed low. We will verify
&& pos.see(ss[ply + 1].currentMove) + nullValue >= beta)
nullDrivenIID = true;
- pos.undo_null_move(u);
+ pos.undo_null_move();
if (value_is_mate(nullValue))
{
/* Do not return unproven mates */
}
- else if (nullValue >= beta)
+ else if (nullValue >= beta - delta)
{
if (depth < 6 * OnePly)
return beta;
Move move, movesSearched[256];
int moveCount = 0;
Value value, bestValue = -VALUE_INFINITE;
+ Bitboard dcCandidates = mp.discovered_check_candidates();
Value futilityValue = VALUE_NONE;
bool useFutilityPruning = UseFutilityPruning
&& depth < SelectiveDepth
assert(move_is_ok(move));
bool singleReply = (isCheck && mp.number_of_moves() == 1);
- bool moveIsCheck = pos.move_is_check(move);
+ bool moveIsCheck = pos.move_is_check(move, dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
movesSearched[moveCount++] = ss[ply].currentMove = move;
}
// Make and search the move
- UndoInfo u;
- pos.do_move(move, u);
+ StateInfo st;
+ pos.do_move(move, st, dcCandidates);
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
&& !AbortSearch
&& !thread_should_stop(threadID)
&& split(pos, ss, ply, &beta, &beta, &bestValue, depth, &moveCount,
- &mp, threadID, false))
+ &mp, dcCandidates, threadID, false))
break;
}
MovePicker mp = MovePicker(pos, pvNode, MOVE_NONE, EmptySearchStack, depth, isCheck ? NULL : &ei);
Move move;
int moveCount = 0;
+ Bitboard dcCandidates = mp.discovered_check_candidates();
Color us = pos.side_to_move();
bool enoughMaterial = pos.non_pawn_material(us) > RookValueMidgame;
&& !isCheck
&& !pvNode
&& !move_promotion(move)
- && !pos.move_is_check(move)
+ && !pos.move_is_check(move, dcCandidates)
&& !pos.move_is_passed_pawn_push(move))
{
Value futilityValue = staticValue
continue;
// Make and search the move.
- UndoInfo u;
- pos.do_move(move, u);
+ StateInfo st;
+ pos.do_move(move, st, dcCandidates);
Value value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID);
pos.undo_move(move);
{
assert(move_is_ok(move));
- bool moveIsCheck = pos.move_is_check(move);
+ bool moveIsCheck = pos.move_is_check(move, sp->dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
lock_grab(&(sp->lock));
continue;
// Make and search the move.
- UndoInfo u;
- pos.do_move(move, u);
+ StateInfo st;
+ pos.do_move(move, st, sp->dcCandidates);
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
&& !thread_should_stop(threadID)
&& (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE)
{
- bool moveIsCheck = pos.move_is_check(move);
+ bool moveIsCheck = pos.move_is_check(move, sp->dcCandidates);
bool moveIsCapture = pos.move_is_capture(move);
assert(move_is_ok(move));
Depth newDepth = sp->depth - OnePly + ext;
// Make and search the move.
- UndoInfo u;
- pos.do_move(move, u);
+ StateInfo st;
+ pos.do_move(move, st, sp->dcCandidates);
// Try to reduce non-pv search depth by one ply if move seems not problematic,
// if the move fails high will be re-searched at full depth.
if (includeMove)
{
// Find a quick score for the move
- UndoInfo u;
+ StateInfo st;
SearchStack ss[PLY_MAX_PLUS_2];
moves[count].move = mlist[i].move;
moves[count].nodes = 0ULL;
- pos.do_move(moves[count].move, u);
+ pos.do_move(moves[count].move, st);
moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE,
Depth(0), 1, 0);
pos.undo_move(moves[count].move);
}
- // init_search_stack() initializes a search stack at the beginning of a
- // new search from the root.
- void init_search_stack(SearchStack& ss) {
-
- ss.pv[0] = MOVE_NONE;
- ss.pv[1] = MOVE_NONE;
- ss.currentMove = MOVE_NONE;
- ss.threatMove = MOVE_NONE;
- ss.reduction = Depth(0);
- for (int j = 0; j < KILLER_MAX; j++)
- ss.killers[j] = MOVE_NONE;
- }
-
- void init_search_stack(SearchStack ss[]) {
-
- for (int i = 0; i < 3; i++)
- {
- ss[i].pv[i] = MOVE_NONE;
- ss[i].pv[i+1] = MOVE_NONE;
- ss[i].currentMove = MOVE_NONE;
- ss[i].threatMove = MOVE_NONE;
- ss[i].reduction = Depth(0);
- for (int j = 0; j < KILLER_MAX; j++)
- ss[i].killers[j] = MOVE_NONE;
- }
- }
-
-
// init_node() is called at the beginning of all the search functions
// (search(), search_pv(), qsearch(), and so on) and initializes the search
// stack object corresponding to the current node. Once every
NodesSincePoll = 0;
}
}
- ss[ply].pv[ply] = ss[ply].pv[ply+1] = ss[ply].currentMove = MOVE_NONE;
- ss[ply+2].mateKiller = MOVE_NONE;
- ss[ply].threatMove = MOVE_NONE;
- ss[ply].reduction = Depth(0);
- ss[ply].currentMoveCaptureValue = Value(0);
- for (int j = 0; j < KILLER_MAX; j++)
- ss[ply+2].killers[j] = MOVE_NONE;
+
+ ss[ply].init(ply);
+ ss[ply+2].initKillers();
if(Threads[threadID].printCurrentLine)
print_current_line(ss, ply, threadID);
// splitPoint->cpus becomes 0), split() returns true.
bool split(const Position &p, SearchStack *sstck, int ply,
- Value *alpha, Value *beta, Value *bestValue,
- Depth depth, int *moves, MovePicker *mp, int master, bool pvNode) {
+ Value *alpha, Value *beta, Value *bestValue, Depth depth, int *moves,
+ MovePicker *mp, Bitboard dcCandidates, int master, bool pvNode) {
+
assert(p.is_ok());
assert(sstck != NULL);
assert(ply >= 0 && ply < PLY_MAX);
splitPoint->alpha = pvNode? *alpha : (*beta - 1);
splitPoint->beta = *beta;
splitPoint->pvNode = pvNode;
+ splitPoint->dcCandidates = dcCandidates;
splitPoint->bestValue = *bestValue;
splitPoint->master = master;
splitPoint->mp = mp;
projects / stockfish / blobdiff