typedef std::vector<RootMove> Base;
RootMoveList(Position& pos, Move searchMoves[]);
- void set_non_pv_scores(const Position& pos);
+ void set_non_pv_scores(const Position& pos, Move ttm, SearchStack* ss);
void sort() { insertion_sort<RootMove, Base::iterator>(begin(), end()); }
- void sort_multipv(int n) { insertion_sort<RootMove, Base::iterator>(begin(), begin() + n + 1); }
+ void sort_multipv(int n) { insertion_sort<RootMove, Base::iterator>(begin(), begin() + n); }
};
bool connected_threat(const Position& pos, Move m, Move threat);
Value refine_eval(const TTEntry* tte, Value defaultEval, int ply);
void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount);
- void update_killers(Move m, SearchStack* ss);
+ void update_killers(Move m, Move killers[]);
void update_gains(const Position& pos, Move move, Value before, Value after);
int current_search_time();
/// perft() is our utility to verify move generation is bug free. All the legal
/// moves up to given depth are generated and counted and the sum returned.
-int perft(Position& pos, Depth depth)
+int64_t perft(Position& pos, Depth depth)
{
MoveStack mlist[MOVES_MAX];
StateInfo st;
Move m;
- int sum = 0;
+ int64_t sum = 0;
// Generate all legal moves
MoveStack* last = generate_moves(pos, mlist);
Value root_search(Position& pos, SearchStack* ss, Value alpha,
Value beta, Depth depth, RootMoveList& rml) {
StateInfo st;
+ Move movesSearched[MOVES_MAX];
CheckInfo ci(pos);
int64_t nodes;
Move move;
Depth ext, newDepth;
Value value, oldAlpha;
- bool isCheck, moveIsCheck, captureOrPromotion, dangerous;
- int researchCountFH, researchCountFL;
+ RootMoveList::iterator rm;
+ bool isCheck, moveIsCheck, captureOrPromotion, dangerous, isPvMove;
+ int moveCount, researchCountFH, researchCountFL;
researchCountFH = researchCountFL = 0;
oldAlpha = alpha;
while (1)
{
// Sort the moves before to (re)search
- rml.set_non_pv_scores(pos);
+ rml.set_non_pv_scores(pos, rml[0].pv[0], ss);
rml.sort();
+ moveCount = 0;
// Step 10. Loop through all moves in the root move list
- for (int i = 0; i < (int)rml.size() && !StopRequest; i++)
+ for (rm = rml.begin(); rm != rml.end() && !StopRequest; ++rm)
{
// This is used by time management
- FirstRootMove = (i == 0);
+ FirstRootMove = (rm == rml.begin());
// Save the current node count before the move is searched
nodes = pos.nodes_searched();
// Pick the next root move, and print the move and the move number to
// the standard output.
- move = ss->currentMove = rml[i].pv[0];
+ move = ss->currentMove = rm->pv[0];
+ movesSearched[moveCount++] = move;
+ isPvMove = (moveCount <= MultiPV);
if (current_search_time() >= 1000)
cout << "info currmove " << move
- << " currmovenumber " << i + 1 << endl;
+ << " currmovenumber " << moveCount << endl;
moveIsCheck = pos.move_is_check(move);
captureOrPromotion = pos.move_is_capture_or_promotion(move);
pos.do_move(move, st, ci, moveIsCheck);
// Step extra. pv search
- // We do pv search for first moves (i < MultiPV)
- // and for fail high research (value > alpha)
- if (i < MultiPV || value > alpha)
+ // We do pv search for PV moves and when failing high
+ if (isPvMove || value > alpha)
{
// Aspiration window is disabled in multi-pv case
if (MultiPV > 1)
&& !captureOrPromotion
&& !move_is_castle(move))
{
- ss->reduction = reduction<PV>(depth, i - MultiPV + 2);
+ ss->reduction = reduction<PV>(depth, moveCount - MultiPV + 1);
if (ss->reduction)
{
assert(newDepth-ss->reduction >= ONE_PLY);
// We are failing high and going to do a research. It's important to update
// the score before research in case we run out of time while researching.
ss->bestMove = move;
- rml[i].pv_score = value;
- rml[i].extract_pv_from_tt(pos);
+ rm->pv_score = value;
+ rm->extract_pv_from_tt(pos);
+
+ // Update killers and history only for non capture moves that fails high
+ if (!pos.move_is_capture_or_promotion(move))
+ {
+ update_history(pos, move, depth, movesSearched, moveCount);
+ update_killers(move, ss->killers);
+ }
// Inform GUI that PV has changed
- cout << rml[i].pv_info_to_uci(pos, alpha, beta) << endl;
+ cout << rm->pv_info_to_uci(pos, alpha, beta) << endl;
// Prepare for a research after a fail high, each time with a wider window
beta = Min(beta + AspirationDelta * (1 << researchCountFH), VALUE_INFINITE);
break;
// Remember searched nodes counts for this move
- rml[i].nodes += pos.nodes_searched() - nodes;
+ rm->nodes += pos.nodes_searched() - nodes;
assert(value >= -VALUE_INFINITE && value <= VALUE_INFINITE);
assert(value < beta);
// Step 17. Check for new best move
- if (value <= alpha && i >= MultiPV)
- rml[i].pv_score = -VALUE_INFINITE;
+ if (!isPvMove && value <= alpha)
+ rm->pv_score = -VALUE_INFINITE;
else
{
// PV move or new best move!
// Update PV
ss->bestMove = move;
- rml[i].pv_score = value;
- rml[i].extract_pv_from_tt(pos);
+ rm->pv_score = value;
+ rm->extract_pv_from_tt(pos);
// We record how often the best move has been changed in each
// iteration. This information is used for time managment: When
// the best move changes frequently, we allocate some more time.
- if (MultiPV == 1 && i > 0)
+ if (!isPvMove && MultiPV == 1)
BestMoveChangesByIteration[Iteration]++;
// Inform GUI that PV has changed, in case of multi-pv UCI protocol
// requires we send all the PV lines properly sorted.
- rml.sort_multipv(i);
+ rml.sort_multipv(moveCount);
for (int j = 0; j < Min(MultiPV, (int)rml.size()); j++)
cout << rml[j].pv_info_to_uci(pos, alpha, beta, j) << endl;
alpha = value;
}
else // Set alpha equal to minimum score among the PV lines
- alpha = rml[Min(i, MultiPV - 1)].pv_score;
+ alpha = rml[Min(moveCount, MultiPV) - 1].pv_score; // FIXME why moveCount?
} // PV move or new best move
&& !pos.move_is_capture_or_promotion(move))
{
update_history(pos, move, depth, movesSearched, moveCount);
- update_killers(move, ss);
+ update_killers(move, ss->killers);
}
}
// update_killers() add a good move that produced a beta-cutoff
// among the killer moves of that ply.
- void update_killers(Move m, SearchStack* ss) {
+ void update_killers(Move m, Move killers[]) {
- if (m == ss->killers[0])
+ if (m == killers[0])
return;
- ss->killers[1] = ss->killers[0];
- ss->killers[0] = m;
+ killers[1] = killers[0];
+ killers[0] = m;
}
// This is the second order score that is used to compare the moves when
// the first order pv scores of both moves are equal.
- void RootMoveList::set_non_pv_scores(const Position& pos)
+ void RootMoveList::set_non_pv_scores(const Position& pos, Move ttm, SearchStack* ss)
{
Move move;
Value score = VALUE_ZERO;
- MovePicker mp(pos, MOVE_NONE, ONE_PLY, H);
+ MovePicker mp(pos, ttm, ONE_PLY, H, ss);
while ((move = mp.get_next_move()) != MOVE_NONE)
for (Base::iterator it = begin(); it != end(); ++it)