Copy killers in the movepicker

[stockfish] / src / movepick.cpp

diff --git a/src/movepick.cpp b/src/movepick.cpp
index cc79528027b25334be0316e2499137cd29c3c3e6..d0ea367a19e9bba7a64bafe1db06d88d6be30bc6 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -34,11 +34,11 @@ namespace {
     QSEARCH_RECAPTURES, QRECAPTURES
   };
 
-  // An insertion sort, which sorts moves in descending order up to and including a given limit.
-  // The order of moves smaller than the limit is left unspecified.
-  // To keep the implementation simple, *begin is always included in the list of sorted moves.
-  void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit)
-  {
+  // partial_insertion_sort() sorts moves in descending order up to and including
+  // a given limit. The order of moves smaller than the limit is left unspecified.
+  // To keep the implementation simple, *begin is always included in the sorted moves.
+  void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) {
+
     for (ExtMove *sortedEnd = begin + 1, *p = begin + 1; p < end; ++p)
         if (p->value >= limit)
         {
@@ -54,10 +54,10 @@ namespace {
   // pick_best() finds the best move in the range (begin, end) and moves it to
   // the front. It's faster than sorting all the moves in advance when there
   // are few moves, e.g., the possible captures.
-  Move pick_best(ExtMove* begin, ExtMove* end)
-  {
-      std::swap(*begin, *std::max_element(begin, end));
-      return *begin;
+  Move pick_best(ExtMove* begin, ExtMove* end) {
+
+    std::swap(*begin, *std::max_element(begin, end));
+    return *begin;
   }
 
 } // namespace
@@ -76,6 +76,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, Search::Stack* s)
 
   Square prevSq = to_sq((ss-1)->currentMove);
   countermove = pos.this_thread()->counterMoves[pos.piece_on(prevSq)][prevSq];
+  killers[0] = ss->killers[0];
+  killers[1] = ss->killers[1];
 
   stage = pos.checkers() ? EVASION : MAIN_SEARCH;
   ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE;
@@ -118,7 +120,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, Value th)
   ttMove =   ttm
           && pos.pseudo_legal(ttm)
           && pos.capture(ttm)
-          && pos.see_ge(ttm, threshold)? ttm : MOVE_NONE;
+          && pos.see_ge(ttm, threshold) ? ttm : MOVE_NONE;
 
   stage += (ttMove == MOVE_NONE);
 }
@@ -210,7 +212,7 @@ Move MovePicker::next_move(bool skipQuiets) {
       }
 
       ++stage;
-      move = ss->killers[0];  // First killer move
+      move = killers[0];  // First killer move
       if (    move != MOVE_NONE
           &&  move != ttMove
           &&  pos.pseudo_legal(move)
@@ -219,7 +221,7 @@ Move MovePicker::next_move(bool skipQuiets) {
 
   case KILLERS:
       ++stage;
-      move = ss->killers[1]; // Second killer move
+      move = killers[1]; // Second killer move
       if (    move != MOVE_NONE
           &&  move != ttMove
           &&  pos.pseudo_legal(move)
@@ -231,8 +233,8 @@ Move MovePicker::next_move(bool skipQuiets) {
       move = countermove;
       if (    move != MOVE_NONE
           &&  move != ttMove
-          &&  move != ss->killers[0]
-          &&  move != ss->killers[1]
+          &&  move != killers[0]
+          &&  move != killers[1]
           &&  pos.pseudo_legal(move)
           && !pos.capture(move))
           return move;
@@ -241,7 +243,6 @@ Move MovePicker::next_move(bool skipQuiets) {
       cur = endBadCaptures;
       endMoves = generate<QUIETS>(pos, cur);
       score<QUIETS>();
-
       partial_insertion_sort(cur, endMoves, -4000 * depth / ONE_PLY);
       ++stage;
 
@@ -252,8 +253,8 @@ Move MovePicker::next_move(bool skipQuiets) {
           move = *cur++;
 
           if (   move != ttMove
-              && move != ss->killers[0]
-              && move != ss->killers[1]
+              && move != killers[0]
+              && move != killers[1]
               && move != countermove)
               return move;
       }