X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=e63d72e85e4d1e08602701e3c006ca17aae0718d;hp=f4e1da977990f18d2b77e988cbbc4c1c0798370e;hb=9dc6d270fc207d6715578b57a1cdf655527ec5fe;hpb=4b88bea4fcd5c4cb931610f97460615dd71ff35b

diff --git a/src/search.cpp b/src/search.cpp
index f4e1da97..e63d72e8 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -948,8 +948,8 @@ moves_loop: // When in check, search starts from here
                &&  pos.see_ge(move))
           extension = ONE_PLY;
 
-      else if (   pos.can_castle(us) // Extension for king moves that change castling rights
-               && type_of(movedPiece) == KING)
+      // Extension if castling
+      else if (type_of(move) == CASTLING)
           extension = ONE_PLY;
 
       // Calculate new depth for this move
@@ -1190,6 +1190,12 @@ moves_loop: // When in check, search starts from here
         // Extra penalty for a quiet TT move in previous ply when it gets refuted
         if ((ss-1)->moveCount == 1 && !pos.captured_piece())
             update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
+
+        // Extra penalty for killer move in previous ply when it gets refuted
+        else if (  (ss-1)->killers[0]
+                && (ss-1)->currentMove == (ss-1)->killers[0]
+                && !pos.captured_piece())
+            update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth));
     }
     // Bonus for prior countermove that caused the fail low
     else if (   (depth >= 3 * ONE_PLY || PvNode)
@@ -1395,21 +1401,15 @@ moves_loop: // When in check, search starts from here
 
           if (value > alpha)
           {
+              bestMove = move;
+
               if (PvNode) // Update pv even in fail-high case
                   update_pv(ss->pv, move, (ss+1)->pv);
 
               if (PvNode && value < beta) // Update alpha here!
-              {
                   alpha = value;
-                  bestMove = move;
-              }
-              else // Fail high
-              {
-                  tte->save(posKey, value_to_tt(value, ss->ply), BOUND_LOWER,
-                            ttDepth, move, ss->staticEval);
-
-                  return value;
-              }
+              else
+                  break; // Fail high
           }
        }
     }
@@ -1420,7 +1420,8 @@ moves_loop: // When in check, search starts from here
         return mated_in(ss->ply); // Plies to mate from the root
 
     tte->save(posKey, value_to_tt(bestValue, ss->ply),
-              PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER,
+              bestValue >= beta ? BOUND_LOWER :
+              PvNode && bestValue > oldAlpha  ? BOUND_EXACT : BOUND_UPPER,
               ttDepth, bestMove, ss->staticEval);
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);