namespace {
- // Set to true to force running with one thread. Used for debugging
- const bool FakeSplit = false;
-
// Different node types, used as template parameter
enum NodeType { Root, PV, NonPV };
return (Depth) Reductions[PvNode][i][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)];
}
- // Tempo bonus. Must be handled by search to preserve eval symmetry.
- const int Tempo = 17;
-
size_t MultiPV, PVIdx;
TimeManager TimeMgr;
double BestMoveChanges;
Value bestValue, alpha, beta, delta;
std::memset(ss-2, 0, 5 * sizeof(Stack));
- (ss-1)->currentMove = MOVE_NULL; // Hack to skip update gains
depth = 0;
BestMoveChanges = 0;
bestValue = -VALUE_INFINITE;
ss->currentMove = ss->ttMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
ss->ply = (ss-1)->ply + 1;
- (ss+1)->skipNullMove = (ss+1)->nullChild = false; (ss+1)->reduction = DEPTH_ZERO;
+ (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
(ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
// Used to send selDepth info to GUI
{
// Step 2. Check for aborted search and immediate draw
if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY)
- return ss->ply > MAX_PLY && !inCheck ? evaluate(pos) + Tempo : DrawValue[pos.side_to_move()];
+ return ss->ply > MAX_PLY && !inCheck ? evaluate(pos) : DrawValue[pos.side_to_move()];
// Step 3. Mate distance pruning. Even if we mate at the next move our score
// would be at best mate_in(ss->ply+1), but if alpha is already bigger because
{
// Never assume anything on values stored in TT
if ((ss->staticEval = eval = tte->eval_value()) == VALUE_NONE)
- eval = ss->staticEval = evaluate(pos) + Tempo;
+ eval = ss->staticEval = evaluate(pos);
// Can ttValue be used as a better position evaluation?
if (ttValue != VALUE_NONE)
}
else
{
- eval = ss->staticEval = ss->nullChild ? -(ss-1)->staticEval + 2 * Tempo : evaluate(pos) + Tempo;
+ eval = ss->staticEval =
+ (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo;
+
TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval);
}
&& ss->staticEval != VALUE_NONE
&& (ss-1)->staticEval != VALUE_NONE
&& (move = (ss-1)->currentMove) != MOVE_NULL
+ && move != MOVE_NONE
&& type_of(move) == NORMAL)
{
Square to = to_sq(move);
&& depth < 4 * ONE_PLY
&& eval + razor_margin(depth) <= alpha
&& ttMove == MOVE_NONE
- && abs(beta) < VALUE_MATE_IN_MAX_PLY
&& !pos.pawn_on_7th(pos.side_to_move()))
{
if ( depth <= ONE_PLY
&& !ss->skipNullMove
&& depth >= 2 * ONE_PLY
&& eval >= beta
- && abs(beta) < VALUE_MATE_IN_MAX_PLY
&& pos.non_pawn_material(pos.side_to_move()))
{
ss->currentMove = MOVE_NULL;
// Null move dynamic reduction based on depth and value
Depth R = 3 * ONE_PLY
+ depth / 4
- + int(eval - beta) / PawnValueMg * ONE_PLY;
+ + (abs(beta) < VALUE_KNOWN_WIN ? int(eval - beta) / PawnValueMg * ONE_PLY
+ : DEPTH_ZERO);
pos.do_null_move(st);
- (ss+1)->skipNullMove = (ss+1)->nullChild = true;
+ (ss+1)->skipNullMove = true;
nullValue = depth-R < ONE_PLY ? -qsearch<NonPV, false>(pos, ss+1, -beta, -beta+1, DEPTH_ZERO)
: - search<NonPV, false>(pos, ss+1, -beta, -beta+1, depth-R, !cutNode);
- (ss+1)->skipNullMove = (ss+1)->nullChild = false;
+ (ss+1)->skipNullMove = false;
pos.undo_null_move();
if (nullValue >= beta)
if (nullValue >= VALUE_MATE_IN_MAX_PLY)
nullValue = beta;
- if (depth < 12 * ONE_PLY)
+ if (depth < 12 * ONE_PLY && abs(beta) < VALUE_KNOWN_WIN)
return nullValue;
// Do verification search at high depths
singularExtensionNode = !RootNode
&& !SpNode
&& depth >= 8 * ONE_PLY
+ && abs(beta) < VALUE_KNOWN_WIN
&& ttMove != MOVE_NONE
+ /* && ttValue != VALUE_NONE Already implicit in the next condition */
+ && abs(ttValue) < VALUE_KNOWN_WIN
&& !excludedMove // Recursive singular search is not allowed
&& (tte->bound() & BOUND_LOWER)
&& tte->depth() >= depth - 3 * ONE_PLY;
if ( singularExtensionNode
&& move == ttMove
&& !ext
- && pos.legal(move, ci.pinned)
- && abs(ttValue) < VALUE_KNOWN_WIN)
+ && pos.legal(move, ci.pinned))
{
- assert(ttValue != VALUE_NONE);
-
Value rBeta = ttValue - int(depth);
ss->excludedMove = move;
ss->skipNullMove = true;
{
assert(bestValue > -VALUE_INFINITE && bestValue < beta);
- thisThread->split<FakeSplit>(pos, ss, alpha, beta, &bestValue, &bestMove,
- depth, moveCount, &mp, NT, cutNode);
+ thisThread->split(pos, ss, alpha, beta, &bestValue, &bestMove,
+ depth, moveCount, &mp, NT, cutNode);
if (Signals.stop || thisThread->cutoff_occurred())
return VALUE_ZERO;
// Check for an instant draw or if the maximum ply has been reached
if (pos.is_draw() || ss->ply > MAX_PLY)
- return ss->ply > MAX_PLY && !InCheck ? evaluate(pos) + Tempo : DrawValue[pos.side_to_move()];
+ return ss->ply > MAX_PLY && !InCheck ? evaluate(pos) : DrawValue[pos.side_to_move()];
// Decide whether or not to include checks: this fixes also the type of
// TT entry depth that we are going to use. Note that in qsearch we use
{
// Never assume anything on values stored in TT
if ((ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE)
- ss->staticEval = bestValue = evaluate(pos) + Tempo;
+ ss->staticEval = bestValue = evaluate(pos);
// Can ttValue be used as a better position evaluation?
if (ttValue != VALUE_NONE)
bestValue = ttValue;
}
else
- ss->staticEval = bestValue = ss->nullChild ? -(ss-1)->staticEval + 2 * Tempo : evaluate(pos) + Tempo;
+ ss->staticEval = bestValue =
+ (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) : -(ss-1)->staticEval + 2 * Eval::Tempo;
// Stand pat. Return immediately if static value is at least beta
if (bestValue >= beta)
projects / stockfish / blobdiff