Position RootPos;
Time::point SearchTime;
StateStackPtr SetupStates;
- int TBCardinality;
- uint64_t TBHits;
+}
+
+namespace Tablebases {
+
+ int Cardinality;
+ uint64_t Hits;
bool RootInTB;
- bool TB50MoveRule;
- Depth TBProbeDepth;
- Value TBScore;
+ bool UseRule50;
+ Depth ProbeDepth;
+ Value Score;
}
+namespace TB = Tablebases;
+
using std::string;
using Eval::evaluate;
using namespace Search;
void Search::think() {
TimeMgr.init(Limits, RootPos.game_ply(), RootPos.side_to_move());
- TBHits = TBCardinality = 0;
- RootInTB = false;
int cf = Options["Contempt"] * PawnValueEg / 100; // From centipawns
DrawValue[ RootPos.side_to_move()] = VALUE_DRAW - Value(cf);
DrawValue[~RootPos.side_to_move()] = VALUE_DRAW + Value(cf);
+ TB::Hits = 0;
+ TB::RootInTB = false;
+ TB::UseRule50 = Options["Syzygy50MoveRule"];
+ TB::ProbeDepth = Options["SyzygyProbeDepth"] * ONE_PLY;
+ TB::Cardinality = Options["SyzygyProbeLimit"];
+
+ // Skip TB probing when no TB found: !TBLargest -> !TB::Cardinality
+ if (TB::Cardinality > TB::TBLargest)
+ {
+ TB::Cardinality = TB::TBLargest;
+ TB::ProbeDepth = DEPTH_ZERO;
+ }
+
if (RootMoves.empty())
{
RootMoves.push_back(MOVE_NONE);
}
else
{
- // Check Tablebases at root
- int piecesCnt = RootPos.count<ALL_PIECES>(WHITE) + RootPos.count<ALL_PIECES>(BLACK);
- TBCardinality = Options["SyzygyProbeLimit"];
- TBProbeDepth = Options["SyzygyProbeDepth"] * ONE_PLY;
- if (TBCardinality > Tablebases::TBLargest)
- {
- TBCardinality = Tablebases::TBLargest;
- TBProbeDepth = 0 * ONE_PLY;
- }
- TB50MoveRule = Options["Syzygy50MoveRule"];
-
- if (piecesCnt <= TBCardinality)
+ if (TB::Cardinality >= RootPos.count<ALL_PIECES>(WHITE)
+ + RootPos.count<ALL_PIECES>(BLACK))
{
- TBHits = RootMoves.size();
-
// If the current root position is in the tablebases then RootMoves
// contains only moves that preserve the draw or win.
- RootInTB = Tablebases::root_probe(RootPos, TBScore);
+ TB::RootInTB = Tablebases::root_probe(RootPos, TB::Score);
- if (RootInTB)
- {
- TBCardinality = 0; // Do not probe tablebases during the search
-
- // It might be a good idea to mangle the hash key (xor it
- // with a fixed value) in order to "clear" the hash table of
- // the results of previous probes. However, that would have to
- // be done from within the Position class, so we skip it for now.
+ if (TB::RootInTB)
+ TB::Cardinality = 0; // Do not probe tablebases during the search
- // Optional: decrease target time.
- }
else // If DTZ tables are missing, use WDL tables as a fallback
{
// Filter out moves that do not preserve a draw or win
- RootInTB = Tablebases::root_probe_wdl(RootPos, TBScore);
+ TB::RootInTB = Tablebases::root_probe_wdl(RootPos, TB::Score);
// Only probe during search if winning
- if (TBScore <= VALUE_DRAW)
- TBCardinality = 0;
+ if (TB::Score <= VALUE_DRAW)
+ TB::Cardinality = 0;
}
- if (!RootInTB)
+ if (TB::RootInTB)
{
- TBHits = 0;
- }
- else if (!TB50MoveRule)
- {
- TBScore = TBScore > VALUE_DRAW ? VALUE_MATE - MAX_PLY - 1
- : TBScore < VALUE_DRAW ? -VALUE_MATE + MAX_PLY + 1
- : TBScore;
+ TB::Hits = RootMoves.size();
+
+ if (!TB::UseRule50)
+ TB::Score = TB::Score > VALUE_DRAW ? VALUE_MATE - MAX_PLY - 1
+ : TB::Score < VALUE_DRAW ? -VALUE_MATE + MAX_PLY + 1
+ : VALUE_DRAW;
}
}
bool inCheck, givesCheck, singularExtensionNode, improving;
bool captureOrPromotion, dangerous, doFullDepthSearch;
int moveCount, quietCount;
- int piecesCnt;
// Step 1. Initialize node
Thread* thisThread = pos.this_thread();
}
// Step 4a. Tablebase probe
- piecesCnt = pos.count<ALL_PIECES>(WHITE) + pos.count<ALL_PIECES>(BLACK);
-
- if ( !RootNode
- && piecesCnt <= TBCardinality
- && (piecesCnt < TBCardinality || depth >= TBProbeDepth)
- && pos.rule50_count() == 0)
+ if (!RootNode && TB::Cardinality)
{
- int found, v = Tablebases::probe_wdl(pos, &found);
+ int piecesCnt = pos.count<ALL_PIECES>(WHITE) + pos.count<ALL_PIECES>(BLACK);
- if (found)
+ if ( piecesCnt <= TB::Cardinality
+ && (piecesCnt < TB::Cardinality || depth >= TB::ProbeDepth)
+ && pos.rule50_count() == 0)
{
- TBHits++;
+ int found, v = Tablebases::probe_wdl(pos, &found);
- if (TB50MoveRule) {
- value = v < -1 ? -VALUE_MATE + MAX_PLY + ss->ply
- : v > 1 ? VALUE_MATE - MAX_PLY - ss->ply
- : VALUE_DRAW + 2 * v;
- }
- else
+ if (found)
{
- value = v < 0 ? -VALUE_MATE + MAX_PLY + ss->ply
- : v > 0 ? VALUE_MATE - MAX_PLY - ss->ply
- : VALUE_DRAW;
- }
+ TB::Hits++;
- TT.store(posKey, value_to_tt(value, ss->ply), BOUND_EXACT,
- std::min(DEPTH_MAX - ONE_PLY, depth + 6 * ONE_PLY), MOVE_NONE, VALUE_NONE);
+ int drawScore = TB::UseRule50 ? 1 : 0;
- return value;
+ value = v < -drawScore ? -VALUE_MATE + MAX_PLY + ss->ply
+ : v > drawScore ? VALUE_MATE - MAX_PLY - ss->ply
+ : VALUE_DRAW + 2 * v * drawScore;
+
+ TT.store(posKey, value_to_tt(value, ss->ply), BOUND_EXACT,
+ std::min(DEPTH_MAX - ONE_PLY, depth + 6 * ONE_PLY),
+ MOVE_NONE, VALUE_NONE);
+
+ return value;
+ }
}
}
Depth d = updated ? depth : depth - ONE_PLY;
Value v = updated ? RootMoves[i].score : RootMoves[i].prevScore;
- bool tb = RootInTB && abs(v) < VALUE_MATE - MAX_PLY;
- v = tb ? TBScore : v;
+ bool tb = TB::RootInTB && abs(v) < VALUE_MATE - MAX_PLY;
+ v = tb ? TB::Score : v;
if (ss.rdbuf()->in_avail()) // Not at first line
ss << "\n";
<< " score " << ((!tb && i == PVIdx) ? UCI::format_value(v, alpha, beta) : UCI::format_value(v))
<< " nodes " << pos.nodes_searched()
<< " nps " << pos.nodes_searched() * 1000 / elapsed
- << " tbhits " << TBHits
+ << " tbhits " << TB::Hits
<< " time " << elapsed
<< " pv";