Don't insert pv back into tt

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 995204f34aab2bf4cca090eb3e66c41f1c857c8a..0b4125fcdd6ccf05279c848c1257eed89c042343 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -413,11 +413,6 @@ void Thread::search() {
               // search the already searched PV lines are preserved.
               std::stable_sort(rootMoves.begin() + PVIdx, rootMoves.end());
 
-              // Write PV back to the transposition table in case the relevant
-              // entries have been overwritten during the search.
-              for (size_t i = 0; i <= PVIdx; ++i)
-                  rootMoves[i].insert_pv_in_tt(rootPos);
-
               // If search has been stopped, break immediately. Sorting and
               // writing PV back to TT is safe because RootMoves is still
               // valid, although it refers to the previous iteration.
@@ -1564,33 +1559,6 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) {
 }
 
 
-/// RootMove::insert_pv_in_tt() is called at the end of a search iteration, and
-/// inserts the PV back into the TT. This makes sure the old PV moves are searched
-/// first, even if the old TT entries have been overwritten.
-
-void RootMove::insert_pv_in_tt(Position& pos) {
-
-  StateInfo state[MAX_PLY], *st = state;
-  bool ttHit;
-
-  for (Move m : pv)
-  {
-      assert(MoveList<LEGAL>(pos).contains(m));
-
-      TTEntry* tte = TT.probe(pos.key(), ttHit);
-
-      if (!ttHit || tte->move() != m) // Don't overwrite correct entries
-          tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE,
-                    m, VALUE_NONE, TT.generation());
-
-      pos.do_move(m, *st++, pos.gives_check(m, CheckInfo(pos)));
-  }
-
-  for (size_t i = pv.size(); i > 0; )
-      pos.undo_move(pv[--i]);
-}
-
-
 /// RootMove::extract_ponder_from_tt() is called in case we have no ponder move
 /// before exiting the search, for instance, in case we stop the search during a
 /// fail high at root. We try hard to have a ponder move to return to the GUI,