Filter root moves filter before copy to threads

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index a26a7bc41c6dbf717231afcd9da6d06fd0656e2a..995204f34aab2bf4cca090eb3e66c41f1c857c8a 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -261,19 +261,6 @@ void MainThread::search() {
   DrawValue[ us] = VALUE_DRAW - Value(contempt);
   DrawValue[~us] = VALUE_DRAW + Value(contempt);
 
-  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::MaxCardinality)
-  {
-      TB::Cardinality = TB::MaxCardinality;
-      TB::ProbeDepth = DEPTH_ZERO;
-  }
-
   if (rootMoves.empty())
   {
       rootMoves.push_back(RootMove(MOVE_NONE));
@@ -283,38 +270,6 @@ void MainThread::search() {
   }
   else
   {
-      if (    TB::Cardinality >=  rootPos.count<ALL_PIECES>(WHITE)
-                                + rootPos.count<ALL_PIECES>(BLACK)
-          && !rootPos.can_castle(ANY_CASTLING))
-      {
-          // If the current root position is in the tablebases, then RootMoves
-          // contains only moves that preserve the draw or the win.
-          TB::RootInTB = Tablebases::root_probe(rootPos, rootMoves, TB::Score);
-
-          if (TB::RootInTB)
-              TB::Cardinality = 0; // Do not probe tablebases during the search
-
-          else // If DTZ tables are missing, use WDL tables as a fallback
-          {
-              // Filter out moves that do not preserve the draw or the win.
-              TB::RootInTB = Tablebases::root_probe_wdl(rootPos, rootMoves, TB::Score);
-
-              // Only probe during search if winning
-              if (TB::Score <= VALUE_DRAW)
-                  TB::Cardinality = 0;
-          }
-
-          if (TB::RootInTB)
-          {
-              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;
-          }
-      }
-
       for (Thread* th : Threads)
           if (th != this)
               th->start_searching();
@@ -1661,3 +1616,49 @@ bool RootMove::extract_ponder_from_tt(Position& pos)
 
     return false;
 }
+
+void Tablebases::filter_root_moves(Position& pos, Search::RootMoves& rootMoves) {
+
+    Hits = 0;
+    RootInTB = false;
+    UseRule50 = Options["Syzygy50MoveRule"];
+    ProbeDepth = Options["SyzygyProbeDepth"] * ONE_PLY;
+    Cardinality = Options["SyzygyProbeLimit"];
+
+    // Skip TB probing when no TB found: !TBLargest -> !TB::Cardinality
+    if (Cardinality > MaxCardinality)
+    {
+        Cardinality = MaxCardinality;
+        ProbeDepth = DEPTH_ZERO;
+    }
+
+    if (Cardinality < popcount(pos.pieces()) || pos.can_castle(ANY_CASTLING))
+        return;
+
+    // If the current root position is in the tablebases, then RootMoves
+    // contains only moves that preserve the draw or the win.
+    RootInTB = root_probe(pos, rootMoves, TB::Score);
+
+    if (RootInTB)
+        Cardinality = 0; // Do not probe tablebases during the search
+
+    else // If DTZ tables are missing, use WDL tables as a fallback
+    {
+        // Filter out moves that do not preserve the draw or the win.
+        RootInTB = root_probe_wdl(pos, rootMoves, TB::Score);
+
+        // Only probe during search if winning
+        if (TB::Score <= VALUE_DRAW)
+            Cardinality = 0;
+    }
+
+    if (RootInTB)
+    {
+        Hits = rootMoves.size();
+
+        if (!UseRule50)
+            TB::Score =  TB::Score > VALUE_DRAW ?  VALUE_MATE - MAX_PLY - 1
+                       : TB::Score < VALUE_DRAW ? -VALUE_MATE + MAX_PLY + 1
+                                                :  VALUE_DRAW;
+    }
+}