Explicitly rely on pthreads if possible

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 1d5bc5f7c844edae9337c367510e01ae60401ae2..ba13680cecbb1e4ade4f3a6264218a2d9679e740 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -939,15 +939,11 @@ namespace {
             }
     }
 
-    // Step 11. Internal iterative deepening (~1 Elo)
-    if (depth >= 7 && !ttMove)
-    {
-        search<NT>(pos, ss, alpha, beta, depth - 7, cutNode);
-
-        tte = TT.probe(posKey, ttHit);
-        ttValue = ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE;
-        ttMove = ttHit ? tte->move() : MOVE_NONE;
-    }
+    // Step 11. If the position is not in TT, decrease depth by 2
+    if (   PvNode
+        && depth >= 6
+        && !ttMove)
+        depth -= 2;
 
 moves_loop: // When in check, search starts from here
 
@@ -1122,6 +1118,11 @@ moves_loop: // When in check, search starts from here
                && (pos.is_discovery_check_on_king(~us, move) || pos.see_ge(move)))
           extension = 1;
 
+      // Last captures extension
+      else if (   PieceValue[EG][pos.captured_piece()] > PawnValueEg
+               && pos.non_pawn_material() <= 2 * RookValueMg)
+          extension = 1;
+
       // Castling extension
       if (   type_of(move) == CASTLING
           && popcount(pos.pieces(us) & ~pos.pieces(PAWN) & (to_sq(move) & KingSide ? KingSide : QueenSide)) <= 2)