Fix moveCount after legality check delay

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 516ff100868655264da9f18a7f2b6282eb61a474..dc6ad98b10a937d07997f52f8cf5faed61e8914a 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -880,6 +880,7 @@ split_point_start: // At split points actual search starts from here
     // Initialize a MovePicker object for the current position
     MovePickerExt<SpNode, Root> mp(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta));
     CheckInfo ci(pos);
+    Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
     ss->bestMove = MOVE_NONE;
     futilityBase = ss->eval + ss->evalMargin;
     singularExtensionNode =   !Root
@@ -903,13 +904,18 @@ split_point_start: // At split points actual search starts from here
     {
       assert(move_is_ok(move));
 
+      if (move == excludedMove)
+          continue;
+
+      // At PV and SpNode nodes we want the moves to be legal
+      if ((PvNode || SpNode) && !pos.pl_move_is_legal(move, pinned))
+          continue;
+
       if (SpNode)
       {
           moveCount = ++sp->moveCount;
           lock_release(&(sp->lock));
       }
-      else if (move == excludedMove)
-          continue;
       else
           moveCount++;
 
@@ -949,6 +955,7 @@ split_point_start: // At split points actual search starts from here
       // a margin then we extend ttMove.
       if (   singularExtensionNode
           && move == ttMove
+          && pos.pl_move_is_legal(move, pinned)
           && ext < ONE_PLY)
       {
           Value ttValue = value_from_tt(tte->value(), ss->ply);
@@ -968,7 +975,6 @@ split_point_start: // At split points actual search starts from here
       }
 
       // Update current move (this must be done after singular extension search)
-      ss->currentMove = move;
       newDepth = depth - ONE_PLY + ext;
 
       // Step 12. Futility pruning (is omitted in PV nodes)
@@ -1023,6 +1029,15 @@ split_point_start: // At split points actual search starts from here
           }
       }
 
+      // Check for legality only before to do the move
+      if (!pos.pl_move_is_legal(move, pinned))
+      {
+          moveCount--;
+          continue;
+      }
+
+      ss->currentMove = move;
+
       // Step 13. Make the move
       pos.do_move(move, st, ci, givesCheck);
 
@@ -1325,6 +1340,7 @@ split_point_start: // At split points actual search starts from here
     // be generated.
     MovePicker mp(pos, ttMove, depth, H);
     CheckInfo ci(pos);
+    Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
 
     // Loop through the moves until no moves remain or a beta cutoff occurs
     while (   alpha < beta
@@ -1362,7 +1378,8 @@ split_point_start: // At split points actual search starts from here
       }
 
       // Detect non-capture evasions that are candidate to be pruned
-      evasionPrunable =   inCheck
+      evasionPrunable =   !PvNode
+                       && inCheck
                        && bestValue > VALUE_MATED_IN_PLY_MAX
                        && !pos.move_is_capture(move)
                        && !pos.can_castle(pos.side_to_move());
@@ -1391,6 +1408,10 @@ split_point_start: // At split points actual search starts from here
           continue;
       }
 
+      // Check for legality only before to do the move
+      if (!pos.pl_move_is_legal(move, pinned))
+          continue;
+
       // Update current move
       ss->currentMove = move;
 
@@ -1983,12 +2004,10 @@ split_point_start: // At split points actual search starts from here
 
     pos.do_move(pv[0], *st++);
 
-    Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
-
     while (   (tte = TT.probe(pos.get_key())) != NULL
            && tte->move() != MOVE_NONE
            && pos.move_is_pl(tte->move())
-           && pos.pl_move_is_legal(tte->move(), pinned)
+           && pos.pl_move_is_legal(tte->move(), pos.pinned_pieces(pos.side_to_move()))
            && ply < PLY_MAX
            && (!pos.is_draw() || ply < 2))
     {