// root move, we store a score, a node count, and a PV (really a refutation
// in the case of moves which fail low).
- class RootMove {
+ struct RootMove {
- public:
RootMove();
+ bool operator<(const RootMove&); // used to sort
+
Move move;
Value score;
int64_t nodes, cumulativeNodes;
void set_move_nodes(int moveNum, int64_t nodes);
void set_move_pv(int moveNum, const Move pv[]);
Move get_move_pv(int moveNum, int i) const;
- int64_t get_move_cumulative_nodes(int moveNum);
+ int64_t get_move_cumulative_nodes(int moveNum) const;
int move_count() const;
Move scan_for_easy_move() const;
void sort();
void sort_multipv(int n);
private:
- static bool compare_root_moves(const RootMove &rm1, const RootMove &rm2);
static const int MaxRootMoves = 500;
RootMove moves[MaxRootMoves];
int count;
bool singleReply, bool mateThreat);
bool ok_to_do_nullmove(const Position &pos);
bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d);
+ bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply);
bool fail_high_ply_1();
int current_search_time();
// We're ready to start thinking. Call the iterative deepening loop
// function:
- id_loop(pos, searchMoves);
+ id_loop(pos, searchMoves);;
if(UseLogFile)
LogFile.close();
// Transposition table lookup. At PV nodes, we don't use the TT for
// pruning, but only for move ordering.
- Value ttValue;
- Depth ttDepth;
- Move ttMove = MOVE_NONE;
- ValueType ttValueType;
+ const TTEntry* tte = TT.retrieve(pos);
- TT.retrieve(pos, &ttValue, &ttDepth, &ttMove, &ttValueType);
+ Move ttMove = (tte ? tte->move() : MOVE_NONE);
- // Internal iterative deepening.
+ // Go with internal iterative deepening if we don't have a TT move.
if(UseIIDAtPVNodes && ttMove == MOVE_NONE && depth >= 5*OnePly) {
search_pv(pos, ss, alpha, beta, depth-2*OnePly, ply, threadID);
ttMove = ss[ply].pv[ply];
return beta-1;
// Transposition table lookup
- bool ttFound;
- Value ttValue;
- Depth ttDepth;
- Move ttMove = MOVE_NONE;
- ValueType ttValueType;
-
- ttFound = TT.retrieve(pos, &ttValue, &ttDepth, &ttMove, &ttValueType);
- if(ttFound) {
- ttValue = value_from_tt(ttValue, ply);
- if(ttDepth >= depth
- || ttValue >= Max(value_mate_in(100), beta)
- || ttValue < Min(value_mated_in(100), beta)) {
- if((is_lower_bound(ttValueType) && ttValue >= beta) ||
- (is_upper_bound(ttValueType) && ttValue < beta)) {
- ss[ply].currentMove = ttMove;
- return ttValue;
- }
- }
+ const TTEntry* tte = TT.retrieve(pos);
+
+ Move ttMove = (tte ? tte->move() : MOVE_NONE);
+
+ if (tte && ok_to_use_TT(tte, depth, beta, ply))
+ {
+ ss[ply].currentMove = ttMove; // can be MOVE_NONE ?
+ return value_from_tt(tte->value(), ply);
}
Value approximateEval = quick_evaluate(pos);
lock_release(&(sp->lock));
}
+ // ok_to_use_TT() returns true if a transposition table score
+ // can be used at a given point in search.
+
+ bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply) {
+
+ Value v = value_from_tt(tte->value(), ply);
+
+ return ( tte->depth() >= depth
+ || v >= Max(value_mate_in(100), beta)
+ || v < Min(value_mated_in(100), beta))
+
+ && ( (is_lower_bound(tte->type()) && v >= beta)
+ || (is_upper_bound(tte->type()) && v < beta));
+ }
/// The RootMove class
nodes = cumulativeNodes = 0ULL;
}
+ // RootMove::operator<() is the comparison function used when
+ // sorting the moves. A move m1 is considered to be better
+ // than a move m2 if it has a higher score, or if the moves
+ // have equal score but m1 has the higher node count.
+
+ bool RootMove::operator<(const RootMove& m) {
+
+ if (score != m.score)
+ return (score < m.score);
+
+ return nodes <= m.nodes;
+ }
/// The RootMoveList class
// Simple accessor methods for the RootMoveList class
- Move RootMoveList::get_move(int moveNum) const {
+ inline Move RootMoveList::get_move(int moveNum) const {
return moves[moveNum].move;
}
- Value RootMoveList::get_move_score(int moveNum) const {
+ inline Value RootMoveList::get_move_score(int moveNum) const {
return moves[moveNum].score;
}
- void RootMoveList::set_move_score(int moveNum, Value score) {
+ inline void RootMoveList::set_move_score(int moveNum, Value score) {
moves[moveNum].score = score;
}
- void RootMoveList::set_move_nodes(int moveNum, int64_t nodes) {
+ inline void RootMoveList::set_move_nodes(int moveNum, int64_t nodes) {
moves[moveNum].nodes = nodes;
moves[moveNum].cumulativeNodes += nodes;
}
moves[moveNum].pv[j] = MOVE_NONE;
}
- Move RootMoveList::get_move_pv(int moveNum, int i) const {
+ inline Move RootMoveList::get_move_pv(int moveNum, int i) const {
return moves[moveNum].pv[i];
}
- int64_t RootMoveList::get_move_cumulative_nodes(int moveNum) {
+ inline int64_t RootMoveList::get_move_cumulative_nodes(int moveNum) const {
return moves[moveNum].cumulativeNodes;
}
- int RootMoveList::move_count() const {
+ inline int RootMoveList::move_count() const {
return count;
}
return MOVE_NONE;
}
-
- // RootMoveList::compare_root_moves() is the comparison function used by
- // RootMoveList::sort when sorting the moves. A move m1 is considered to
- // be better than a move m2 if it has a higher score, or if the moves have
- // equal score but m1 has the higher node count.
-
- bool RootMoveList::compare_root_moves(const RootMove &rm1,
- const RootMove &rm2) {
- if (rm1.score != rm2.score)
- return (rm1.score < rm2.score);
-
- return rm1.nodes <= rm2.nodes;
- }
-
-
// RootMoveList::sort() sorts the root move list at the beginning of a new
// iteration.
- void RootMoveList::sort() {
- for(int i = 1; i < count; i++) {
- RootMove rm = moves[i];
- int j;
- for(j = i; j > 0 && compare_root_moves(moves[j-1], rm); j--)
- moves[j] = moves[j-1];
- moves[j] = rm;
- }
+ inline void RootMoveList::sort() {
+
+ sort_multipv(count - 1); // all items
}
// RootMoveList::sort_multipv() sorts the first few moves in the root move
- // list by their scores and depths. It is used to order the different PVs
+ // list by their scores and depths. It is used to order the different PVs
// correctly in MultiPV mode.
void RootMoveList::sort_multipv(int n) {
- for(int i = 1; i <= n; i++) {
+
+ for (int i = 1; i <= n; i++)
+ {
RootMove rm = moves[i];
int j;
- for(j = i; j > 0 && moves[j-1].score < rm.score; j--)
- moves[j] = moves[j-1];
+ for (j = i; j > 0 && moves[j-1] < rm; j--)
+ moves[j] = moves[j-1];
moves[j] = rm;
}
}