// TT value, so we use a different position key in case of an excluded move.
excludedMove = ss->excludedMove;
posKey = excludedMove ? pos.get_exclusion_key() : pos.get_key();
-
tte = TT.probe(posKey);
ttMove = tte ? tte->move() : MOVE_NONE;
if (move == excludedMove)
continue;
- // At PV and SpNode nodes we want the moves to be legal
+ // At PV and SpNode nodes we want all moves to be legal since the beginning
if ((PvNode || SpNode) && !pos.pl_move_is_legal(move, ci.pinned))
continue;
cout << "info" << speed_to_uci(pos.nodes_searched()) << endl;
}
- // For long searches send to GUI current move
+ // For long searches send current move info to GUI
if (current_search_time() > 2000)
cout << "info" << depth_to_uci(depth)
<< " currmove " << move << " currmovenumber " << moveCount << endl;
}
// At Root and at first iteration do a PV search on all the moves to score root moves
- isPvMove = (PvNode && moveCount <= (RootNode ? depth <= ONE_PLY ? MAX_MOVES : MultiPV : 1));
+ isPvMove = (PvNode && moveCount <= (!RootNode ? 1 : depth <= ONE_PLY ? MAX_MOVES : MultiPV));
givesCheck = pos.move_gives_check(move, ci);
captureOrPromotion = pos.move_is_capture_or_promotion(move);
}
ss->currentMove = move;
+ if (!SpNode && !captureOrPromotion)
+ movesSearched[playedMoveCount++] = move;
// Step 14. Make the move
pos.do_move(move, st, ci, givesCheck);
- if (!SpNode && !captureOrPromotion)
- movesSearched[playedMoveCount++] = move;
-
// Step extra. pv search (only in PV nodes)
// The first move in list is the expected PV
if (isPvMove)
// Step 15. Reduced depth search
// If the move fails high will be re-searched at full depth.
bool doFullDepthSearch = true;
- alpha = SpNode ? sp->alpha : alpha;
if ( depth > 3 * ONE_PLY
&& !captureOrPromotion
&& !dangerous
&& !move_is_castle(move)
&& ss->killers[0] != move
- && ss->killers[1] != move)
+ && ss->killers[1] != move
+ && (ss->reduction = reduction<PvNode>(depth, moveCount)) != DEPTH_ZERO)
{
- ss->reduction = reduction<PvNode>(depth, moveCount);
- if (ss->reduction)
- {
- Depth d = newDepth - ss->reduction;
- value = d < ONE_PLY ? -qsearch<NonPV>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
- : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d);
- doFullDepthSearch = (value > alpha);
- }
- ss->reduction = DEPTH_ZERO; // Restore original reduction
+ Depth d = newDepth - ss->reduction;
+ alpha = SpNode ? sp->alpha : alpha;
+
+ value = d < ONE_PLY ? -qsearch<NonPV>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
+ : - search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d);
+
+ ss->reduction = DEPTH_ZERO;
+ doFullDepthSearch = (value > alpha);
}
// Step 16. Full depth search
alpha = sp->alpha;
}
- if (value > bestValue && !(SpNode && thread.cutoff_occurred()))
+ if (value > bestValue)
{
bestValue = value;
+ ss->bestMove = move;
- if (SpNode)
- sp->bestValue = value;
+ if ( !RootNode
+ && PvNode
+ && value > alpha
+ && value < beta) // We want always alpha < beta
+ alpha = value;
- if (!RootNode && value > alpha)
+ if (SpNode && !thread.cutoff_occurred())
{
- if (PvNode && value < beta) // We want always alpha < beta
- {
- alpha = value;
-
- if (SpNode)
- sp->alpha = value;
- }
- else if (SpNode)
- sp->is_betaCutoff = true;
-
- ss->bestMove = move;
-
- if (SpNode)
- sp->ss->bestMove = move;
+ sp->bestValue = value;
+ sp->ss->bestMove = move;
+ sp->alpha = alpha;
+ sp->is_betaCutoff = (value >= beta);
}
}
if (isPvMove || value > alpha)
{
// Update PV
- ss->bestMove = move;
mp.current().pv_score = value;
mp.current().extract_pv_from_tt(pos);