size_t Search::perft(Position& pos, Depth depth) {
- // At the last ply just return the number of legal moves (leaf nodes)
- if (depth == ONE_PLY)
- return MoveList<LEGAL>(pos).size();
-
StateInfo st;
size_t cnt = 0;
CheckInfo ci(pos);
+ const bool leaf = depth == 2 * ONE_PLY;
for (MoveList<LEGAL> it(pos); *it; ++it)
{
pos.do_move(*it, st, ci, pos.move_gives_check(*it, ci));
- cnt += perft(pos, depth - ONE_PLY);
+ cnt += leaf ? MoveList<LEGAL>(pos).size() : perft(pos, depth - ONE_PLY);
pos.undo_move(*it);
}
-
return cnt;
}
&& tte
&& tte->depth() >= depth
&& ttValue != VALUE_NONE // Only in case of TT access race
- && ( PvNode ? tte->type() == BOUND_EXACT
- : ttValue >= beta ? (tte->type() & BOUND_LOWER)
- : (tte->type() & BOUND_UPPER)))
+ && ( PvNode ? tte->bound() == BOUND_EXACT
+ : ttValue >= beta ? (tte->bound() & BOUND_LOWER)
+ : (tte->bound() & BOUND_UPPER)))
{
TT.refresh(tte);
ss->currentMove = ttMove; // Can be MOVE_NONE
// Can ttValue be used as a better position evaluation?
if (ttValue != VALUE_NONE)
- if ( ((tte->type() & BOUND_LOWER) && ttValue > eval)
- || ((tte->type() & BOUND_UPPER) && ttValue < eval))
+ if ( ((tte->bound() & BOUND_LOWER) && ttValue > eval)
+ || ((tte->bound() & BOUND_UPPER) && ttValue < eval))
eval = ttValue;
}
else
&& depth >= 5 * ONE_PLY
&& !inCheck
&& !ss->skipNullMove
- && excludedMove == MOVE_NONE
&& abs(beta) < VALUE_MATE_IN_MAX_PLY)
{
Value rbeta = beta + 200;
&& depth >= (PvNode ? 6 * ONE_PLY : 8 * ONE_PLY)
&& ttMove != MOVE_NONE
&& !excludedMove // Recursive singular search is not allowed
- && (tte->type() & BOUND_LOWER)
+ && (tte->bound() & BOUND_LOWER)
&& tte->depth() >= depth - 3 * ONE_PLY;
// Step 11. Loop through moves
&& move != ss->killers[1])
{
ss->reduction = reduction<PvNode>(depth, moveCount);
+
+ if (!PvNode && cutNode)
+ ss->reduction += ONE_PLY;
+
if (move == countermoves[0] || move == countermoves[1])
ss->reduction = std::max(DEPTH_ZERO, ss->reduction-ONE_PLY);
if ( tte
&& tte->depth() >= ttDepth
&& ttValue != VALUE_NONE // Only in case of TT access race
- && ( PvNode ? tte->type() == BOUND_EXACT
- : ttValue >= beta ? (tte->type() & BOUND_LOWER)
- : (tte->type() & BOUND_UPPER)))
+ && ( PvNode ? tte->bound() == BOUND_EXACT
+ : ttValue >= beta ? (tte->bound() & BOUND_LOWER)
+ : (tte->bound() & BOUND_UPPER)))
{
ss->currentMove = ttMove; // Can be MOVE_NONE
return ttValue;
void RootMove::extract_pv_from_tt(Position& pos) {
StateInfo state[MAX_PLY_PLUS_2], *st = state;
- TTEntry* tte;
+ const TTEntry* tte;
int ply = 0;
Move m = pv[0];
void RootMove::insert_pv_in_tt(Position& pos) {
StateInfo state[MAX_PLY_PLUS_2], *st = state;
- TTEntry* tte;
+ const TTEntry* tte;
int ply = 0;
do {