Enable Futility pruning in PV nodes

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 1f77e0aab3a3c94e114246d085bcbde10f741a85..7e3f6ca58bd550d8cd525a69f0b0a618bfddc795 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -632,7 +632,7 @@ namespace {
     }
 
     // Step 7. Futility pruning: child node (skipped when in check)
-    if (   !PvNode
+    if (   !RootNode
         &&  depth < 7 * ONE_PLY
         &&  eval - futility_margin(depth) >= beta
         &&  eval < VALUE_KNOWN_WIN  // Do not return unproven wins
@@ -829,9 +829,8 @@ moves_loop: // When in check and at SpNode search starts from here
       // Update the current move (this must be done after singular extension search)
       newDepth = depth - ONE_PLY + extension;
 
-      // Step 13. Pruning at shallow depth (exclude PV nodes)
-      if (   !PvNode
-          && !captureOrPromotion
+      // Step 13. Pruning at shallow depth
+      if (   !captureOrPromotion
           && !inCheck
           && !dangerous
           &&  bestValue > VALUE_MATED_IN_MAX_PLY)
@@ -906,7 +905,7 @@ moves_loop: // When in check and at SpNode search starts from here
           ss->reduction = reduction<PvNode>(improving, depth, moveCount);
 
           if (   (!PvNode && cutNode)
-              ||  History[pos.piece_on(to_sq(move))][to_sq(move)] < 0)
+              ||  History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO)
               ss->reduction += ONE_PLY;
 
           if (move == countermoves[0] || move == countermoves[1])
@@ -916,7 +915,7 @@ moves_loop: // When in check and at SpNode search starts from here
           if (   ss->reduction
               && type_of(move) == NORMAL
               && type_of(pos.piece_on(to_sq(move))) != PAWN
-              && pos.see(make_move(to_sq(move), from_sq(move))) < 0)
+              && pos.see(make_move(to_sq(move), from_sq(move))) < VALUE_ZERO)
               ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY);
 
           Depth d = std::max(newDepth - ss->reduction, ONE_PLY);