// Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply
const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) };
- // The main transposition table
- TranspositionTable TT;
-
/// Variables initialized by UCI options
void update_history(const Position& pos, Move m, Depth depth, Move movesSearched[], int moveCount);
void update_killers(Move m, SearchStack& ss);
void slowdown(const Position& pos);
- void build_pv(const Position& pos, Move pv[]);
bool fail_high_ply_1();
int current_search_time();
// Decide search depth for this move
bool moveIsCapture = pos.move_is_capture(move);
bool dangerous;
- ext = extension(pos, move, true, pos.move_is_capture(move), pos.move_is_check(move), false, false, &dangerous);
+ ext = extension(pos, move, true, moveIsCapture, pos.move_is_check(move), false, false, &dangerous);
newDepth = (Iteration - 2) * OnePly + ext + InitialDepth;
// Make the move, and search it
}
else
{
- if (newDepth >= 3*OnePly
- && i + MultiPV >= LMRPVMoves
+ if ( newDepth >= 3*OnePly
+ && i >= MultiPV + LMRPVMoves - 2 // Remove -2 and decrease LMRPVMoves instead ?
&& !dangerous
&& !moveIsCapture
&& !move_is_promotion(move)
{
ss[0].reduction = OnePly;
value = -search(pos, ss, -alpha, newDepth-OnePly, 1, true, 0);
- }
- else
+ } else
value = alpha + 1; // Just to trigger next condition
- if(value > alpha)
+
+ if (value > alpha)
{
value = -search(pos, ss, -alpha, newDepth, 1, true, 0);
if (value > alpha)
// Update PV
rml.set_move_score(i, value);
update_pv(ss, 0);
- build_pv(pos, ss[0].pv);
+ TT.extract_pv(pos, ss[0].pv);
rml.set_move_pv(i, ss[0].pv);
if (MultiPV == 1)
// Print search information to the standard output
std::cout << "info depth " << Iteration
<< " score " << value_to_string(value)
+ << ((value >= beta)?
+ " lowerbound" : ((value <= alpha)? " upperbound" : ""))
<< " time " << current_search_time()
<< " nodes " << nodes_searched()
<< " nps " << nps()
}
- // build_pv() extends a PV by adding moves from the transposition table at
- // the end. This should ensure that the PV is almost always at least two
- // plies long, which is important, because otherwise we will often get
- // single-move PVs when the search stops while failing high, and a
- // single-move PV means that we don't have a ponder move.
-
- void build_pv(const Position& pos, Move pv[]) {
- int ply;
- Position p(pos);
- StateInfo st[100];
-
- for (ply = 0; pv[ply] != MOVE_NONE; ply++)
- p.do_move(pv[ply], st[ply]);
-
- bool stop;
- const TTEntry* tte;
- for (stop = false, tte = TT.retrieve(p.get_key());
- tte && tte->move() != MOVE_NONE && !stop;
- tte = TT.retrieve(p.get_key()), ply++)
- {
- if (!move_is_legal(p, tte->move(), p.pinned_pieces(p.side_to_move())))
- break;
- pv[ply] = tte->move();
- p.do_move(pv[ply], st[ply]);
- for (int j = 0; j < ply; j++)
- if (st[j].key == p.get_key()) stop = true;
- }
- pv[ply] = MOVE_NONE;
- }
-
-
// fail_high_ply_1() checks if some thread is currently resolving a fail
// high at ply 1 at the node below the first root node. This information
// is used for time managment.