X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=c80a064dfde82ba15f1eb98550d9eda5ebf11107;hp=35160b9665a39d6ed99bae69da65940ebf9f049b;hb=239d7b3fd144d2b493bb47ea97a436cec8ae5990;hpb=47f988f05fb86b0cd9187885b1cfa942addbeee6

diff --git a/src/search.cpp b/src/search.cpp
index 35160b96..c80a064d 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -62,10 +62,6 @@ namespace {
   // Different node types, used as template parameter
   enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV };
 
-  // Lookup table to check if a Piece is a slider and its access function
-  const bool Slidings[18] = { 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1 };
-  inline bool piece_is_slider(Piece p) { return Slidings[p]; }
-
   // Dynamic razoring margin based on depth
   inline Value razor_margin(Depth d) { return Value(512 + 16 * int(d)); }
 
@@ -222,7 +218,7 @@ void Search::think() {
   if (Options["Use Search Log"])
   {
       Log log(Options["Search Log Filename"]);
-      log << "\nSearching: "  << RootPos.to_fen()
+      log << "\nSearching: "  << RootPos.fen()
           << "\ninfinite: "   << Limits.infinite
           << " ponder: "      << Limits.ponder
           << " time: "        << Limits.time[RootColor]
@@ -1020,8 +1016,12 @@ split_point_start: // At split points actual search starts from here
           &&  depth >= Threads.min_split_depth()
           &&  bestValue < beta
           &&  Threads.available_slave_exists(thisThread))
+      {
           bestValue = Threads.split<FakeSplit>(pos, ss, alpha, beta, bestValue, &bestMove,
                                                depth, threatMove, moveCount, mp, NT);
+          if (bestValue >= beta)
+              break;
+      }
     }
 
     if (SpNode)
@@ -1101,12 +1101,17 @@ split_point_start: // At split points actual search starts from here
     const TTEntry* tte;
     Key posKey;
     Move ttMove, move, bestMove;
-    Value bestValue, value, ttValue, futilityValue, futilityBase;
-    bool givesCheck, enoughMaterial, evasionPrunable;
+    Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
+    bool givesCheck, enoughMaterial, evasionPrunable, fromNull;
     Depth ttDepth;
 
+    // To flag BOUND_EXACT a node with eval above alpha and no available moves
+    if (PvNode)
+        oldAlpha = alpha;
+
     ss->currentMove = bestMove = MOVE_NONE;
     ss->ply = (ss-1)->ply + 1;
+    fromNull = (ss-1)->currentMove == MOVE_NULL;
 
     // Check for an instant draw or maximum ply reached
     if (pos.is_draw<false, false>() || ss->ply > MAX_PLY)
@@ -1144,7 +1149,12 @@ split_point_start: // At split points actual search starts from here
     }
     else
     {
-        if (tte)
+        if (fromNull)
+        {
+            ss->staticEval = bestValue = -(ss-1)->staticEval;
+            ss->evalMargin = VALUE_ZERO;
+        }
+        else if (tte)
         {
             assert(tte->static_value() != VALUE_NONE || Threads.size() > 1);
 
@@ -1192,6 +1202,7 @@ split_point_start: // At split points actual search starts from here
       if (   !PvNode
           && !InCheck
           && !givesCheck
+          && !fromNull
           &&  move != ttMove
           &&  enoughMaterial
           &&  type_of(move) != PROMOTION
@@ -1284,7 +1295,7 @@ split_point_start: // At split points actual search starts from here
         return mated_in(ss->ply); // Plies to mate from the root
 
     TT.store(posKey, value_to_tt(bestValue, ss->ply),
-             PvNode && bestMove != MOVE_NONE ? BOUND_EXACT : BOUND_UPPER,
+             PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER,
              ttDepth, bestMove, ss->staticEval, ss->evalMargin);
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
@@ -1437,10 +1448,8 @@ split_point_start: // At split points actual search starts from here
             return true;
     }
 
-    // If the threat piece is a slider, don't prune safe moves which block it
-    if (    piece_is_slider(pos.piece_on(tfrom))
-        && (between_bb(tfrom, tto) & mto)
-        &&  pos.see_sign(move) >= 0)
+    // Don't prune safe moves which block the threat path
+    if ((between_bb(tfrom, tto) & mto) && pos.see_sign(move) >= 0)
         return true;
 
     return false;