// Find out minimum score and reset votes for moves which can be voted
for (Thread* th: Threads)
- {
minScore = std::min(minScore, th->rootMoves[0].score);
- votes[th->rootMoves[0].pv[0]] = 0;
- }
// Vote according to score and depth
- auto square = [](int64_t x) { return x * x; };
for (Thread* th : Threads)
- votes[th->rootMoves[0].pv[0]] += 200 + (square(th->rootMoves[0].score - minScore + 1)
- * int64_t(th->completedDepth));
+ {
+ int64_t s = th->rootMoves[0].score - minScore + 1;
+ votes[th->rootMoves[0].pv[0]] += 200 + s * s * int(th->completedDepth);
+ }
// Select best thread
- int64_t bestVote = votes[this->rootMoves[0].pv[0]];
+ auto bestVote = votes[this->rootMoves[0].pv[0]];
for (Thread* th : Threads)
- {
if (votes[th->rootMoves[0].pv[0]] > bestVote)
{
bestVote = votes[th->rootMoves[0].pv[0]];
bestThread = th;
}
- }
}
previousScore = bestThread->rootMoves[0].score;
Move ttMove, move, excludedMove, bestMove;
Depth extension, newDepth;
Value bestValue, value, ttValue, eval, maxValue, pureStaticEval;
- bool ttHit, pvHit, inCheck, givesCheck, improving;
+ bool ttHit, ttPv, inCheck, givesCheck, improving;
bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture;
Piece movedPiece;
int moveCount, captureCount, quietCount;
ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
ttMove = rootNode ? thisThread->rootMoves[thisThread->pvIdx].pv[0]
: ttHit ? tte->move() : MOVE_NONE;
- pvHit = (ttHit && tte->pv_hit()) || (PvNode && depth > 4 * ONE_PLY);
+ ttPv = (ttHit && tte->is_pv()) || (PvNode && depth > 4 * ONE_PLY);
// At non-PV nodes we check for an early TT cutoff
if ( !PvNode
if ( b == BOUND_EXACT
|| (b == BOUND_LOWER ? value >= beta : value <= alpha))
{
- tte->save(posKey, value_to_tt(value, ss->ply), pvHit, b,
+ tte->save(posKey, value_to_tt(value, ss->ply), ttPv, b,
std::min(DEPTH_MAX - ONE_PLY, depth + 6 * ONE_PLY),
MOVE_NONE, VALUE_NONE);
else
ss->staticEval = eval = pureStaticEval = -(ss-1)->staticEval + 2 * Eval::Tempo;
- tte->save(posKey, VALUE_NONE, pvHit, BOUND_NONE, DEPTH_NONE, MOVE_NONE, pureStaticEval);
+ tte->save(posKey, VALUE_NONE, ttPv, BOUND_NONE, DEPTH_NONE, MOVE_NONE, pureStaticEval);
}
// Step 7. Razoring (~2 Elo)
else if (cutNode && singularBeta > beta)
return beta;
}
- else if ( givesCheck // Check extension (~2 Elo)
- && pos.see_ge(move))
+
+ // Check extension (~2 Elo)
+ else if ( givesCheck
+ && (pos.blockers_for_king(~us) & from_sq(move) || pos.see_ge(move)))
extension = ONE_PLY;
- // Extension if castling
+ // Castling extension
else if (type_of(move) == CASTLING)
extension = ONE_PLY;
Depth r = reduction<PvNode>(improving, depth, moveCount);
// Decrease reduction if position is or has been on the PV
- if (pvHit)
+ if (ttPv)
r -= ONE_PLY;
// Decrease reduction if opponent's move count is high (~10 Elo)
bestValue = std::min(bestValue, maxValue);
if (!excludedMove)
- tte->save(posKey, value_to_tt(bestValue, ss->ply), pvHit,
+ tte->save(posKey, value_to_tt(bestValue, ss->ply), ttPv,
bestValue >= beta ? BOUND_LOWER :
PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
depth, bestMove, pureStaticEval);
tte = TT.probe(posKey, ttHit);
ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE;
ttMove = ttHit ? tte->move() : MOVE_NONE;
- pvHit = ttHit && tte->pv_hit();
+ pvHit = ttHit && tte->is_pv();
if ( !PvNode
&& ttHit