assert(0 <= ss->ply && ss->ply < MAX_PLY);
ss->currentMove = ss->ttMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
- (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
+ (ss+1)->skipEarlyPruning = false; (ss+1)->reduction = DEPTH_ZERO;
(ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
// Step 4. Transposition table lookup
TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval);
}
+ if (ss->skipEarlyPruning)
+ goto moves_loop;
+
if ( !pos.captured_piece_type()
&& ss->staticEval != VALUE_NONE
&& (ss-1)->staticEval != VALUE_NONE
// Step 7. Futility pruning: child node (skipped when in check)
if ( !PvNode
- && !ss->skipNullMove
&& depth < 7 * ONE_PLY
&& eval - futility_margin(depth) >= beta
&& eval < VALUE_KNOWN_WIN // Do not return unproven wins
// Step 8. Null move search with verification search (is omitted in PV nodes)
if ( !PvNode
- && !ss->skipNullMove
&& depth >= 2 * ONE_PLY
&& eval >= beta
&& pos.non_pawn_material(pos.side_to_move()))
Depth R = (3 + depth / 4 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
pos.do_null_move(st);
- (ss+1)->skipNullMove = true;
+ (ss+1)->skipEarlyPruning = 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 = false;
+ (ss+1)->skipEarlyPruning = false;
pos.undo_null_move();
if (nullValue >= beta)
return nullValue;
// Do verification search at high depths
- ss->skipNullMove = true;
+ ss->skipEarlyPruning = true;
Value v = depth-R < ONE_PLY ? qsearch<NonPV, false>(pos, ss, beta-1, beta, DEPTH_ZERO)
: search<NonPV, false>(pos, ss, beta-1, beta, depth-R, false);
- ss->skipNullMove = false;
+ ss->skipEarlyPruning = false;
if (v >= beta)
return nullValue;
// prune the previous move.
if ( !PvNode
&& depth >= 5 * ONE_PLY
- && !ss->skipNullMove
&& abs(beta) < VALUE_MATE_IN_MAX_PLY)
{
Value rbeta = std::min(beta + 200, VALUE_INFINITE);
&& (PvNode || ss->staticEval + 256 >= beta))
{
Depth d = 2 * (depth - 2 * ONE_PLY) - (PvNode ? DEPTH_ZERO : depth / 2);
- ss->skipNullMove = true;
+ ss->skipEarlyPruning = true;
search<PvNode ? PV : NonPV, false>(pos, ss, alpha, beta, d / 2, true);
- ss->skipNullMove = false;
+ ss->skipEarlyPruning = false;
tte = TT.probe(posKey);
ttMove = tte ? tte->move() : MOVE_NONE;
{
Value rBeta = ttValue - 2 * depth / ONE_PLY;
ss->excludedMove = move;
- ss->skipNullMove = true;
+ ss->skipEarlyPruning = true;
value = search<NonPV, false>(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode);
- ss->skipNullMove = false;
+ ss->skipEarlyPruning = false;
ss->excludedMove = MOVE_NONE;
if (value < rBeta)