pos.undo_null_move();
- if (value_is_mate(nullValue))
- {
- if (nullValue == value_mated_in(ply + 2))
- mateThreat = true;
-
- /* Do not return unproven mates */
- }
- else if (nullValue >= beta)
+ if (nullValue >= beta)
{
if (depth < 6 * OnePly)
return beta;
// move which was reduced. If a connection is found, return a fail
// low score (which will cause the reduced move to fail high in the
// parent node, which will trigger a re-search with full depth).
+ if (nullValue == value_mated_in(ply + 2))
+ mateThreat = true;
+
ss[ply].threatMove = ss[ply + 1].currentMove;
if ( depth < ThreatDepth
&& ss[ply - 1].reduction
assert(m != MOVE_NONE);
Depth result = Depth(0);
- *dangerous = check || singleReply || mateThreat;
+ *dangerous = check | singleReply | mateThreat;
- if (check)
- result += CheckExtension[pvNode];
+ if (*dangerous)
+ {
+ if (check)
+ result += CheckExtension[pvNode];
- if (singleReply)
- result += SingleReplyExtension[pvNode];
+ if (singleReply)
+ result += SingleReplyExtension[pvNode];
- if (mateThreat)
- result += MateThreatExtension[pvNode];
+ if (mateThreat)
+ result += MateThreatExtension[pvNode];
+ }
if (pos.type_of_piece_on(move_from(m)) == PAWN)
{