Merge Joona's increased static null pruning

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 267f5f8f4c64c87fbacc15f9184a16242dbcd394..0e68178147c7b2cbba34845c89e57218e6ea9b86 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -643,10 +643,10 @@ namespace {
         && !ss->skipNullMove
         &&  depth < 4 * ONE_PLY
         && !inCheck
         && !ss->skipNullMove
         &&  depth < 4 * ONE_PLY
         && !inCheck

-        &&  eval - futility_margin(depth, (ss-1)->futMc) >= beta
+        &&  eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta

         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         &&  pos.non_pawn_material(pos.side_to_move()))
         &&  abs(beta) < VALUE_MATE_IN_MAX_PLY
         &&  pos.non_pawn_material(pos.side_to_move()))

-        return eval - futility_margin(depth, (ss-1)->futMc);
+        return eval - futility_margin(depth, (ss-1)->futilityMoveCount);

 
     // Step 8. Null move search with verification search (is omitted in PV nodes)
     if (   !PvNode
 
     // Step 8. Null move search with verification search (is omitted in PV nodes)
     if (   !PvNode


@@ -806,6 +806,7 @@ split_point_start: // At split points actual search starts from here
                         << " currmovenumber " << moveCount + PVIdx << sync_endl;
       }
 
                         << " currmovenumber " << moveCount + PVIdx << sync_endl;
       }
 

+      ss->futilityMoveCount = 0;

       ext = DEPTH_ZERO;
       captureOrPromotion = pos.is_capture_or_promotion(move);
       givesCheck = pos.move_gives_check(move, ci);
       ext = DEPTH_ZERO;
       captureOrPromotion = pos.is_capture_or_promotion(move);
       givesCheck = pos.move_gives_check(move, ci);


@@ -852,8 +853,6 @@ split_point_start: // At split points actual search starts from here
       // Update current move (this must be done after singular extension search)
       newDepth = depth - ONE_PLY + ext;
 
       // Update current move (this must be done after singular extension search)
       newDepth = depth - ONE_PLY + ext;
 

-      ss->futMc = 0;
-

       // Step 13. Futility pruning (is omitted in PV nodes)
       if (   !PvNode
           && !captureOrPromotion
       // Step 13. Futility pruning (is omitted in PV nodes)
       if (   !PvNode
           && !captureOrPromotion


@@ -876,8 +875,6 @@ split_point_start: // At split points actual search starts from here
           // Value based pruning
           // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth,
           // but fixing this made program slightly weaker.
           // Value based pruning
           // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth,
           // but fixing this made program slightly weaker.

-          ss->futMc = moveCount;
-

           Depth predictedDepth = newDepth - reduction<PvNode>(depth, moveCount);
           futilityValue =  ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount)
                          + Gain[pos.piece_moved(move)][to_sq(move)];
           Depth predictedDepth = newDepth - reduction<PvNode>(depth, moveCount);
           futilityValue =  ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount)
                          + Gain[pos.piece_moved(move)][to_sq(move)];


@@ -904,6 +901,10 @@ split_point_start: // At split points actual search starts from here
 
               continue;
           }
 
               continue;
           }

+
+          // We have not pruned the move that will be searched, but remember how
+          // far in the move list we are to be more aggressive in the child node.
+          ss->futilityMoveCount = moveCount;

       }
 
       // Check for legality only before to do the move
       }
 
       // Check for legality only before to do the move