--- old/src/hotspot/share/gc/shared/c2/barrierSetC2.hpp	2018-11-27 14:44:44.546465106 +0100
+++ new/src/hotspot/share/gc/shared/c2/barrierSetC2.hpp	2018-11-27 14:44:39.089510276 +0100
@@ -61,6 +61,7 @@
 class IdealKit;
 class Node;
 class PhaseGVN;
+class PhaseIdealLoop;
 class PhaseMacroExpand;
 class Type;
 class TypePtr;
@@ -309,6 +310,7 @@
   virtual void igvn_add_users_to_worklist(PhaseIterGVN* igvn, Node* use) const {}
   virtual void ccp_analyze(PhaseCCP* ccp, Unique_Node_List& worklist, Node* use) const {}
 
+  virtual Node* split_if_pre(PhaseIdealLoop* phase, Node* n) const { return NULL; }
 };
 
 #endif // SHARE_GC_SHARED_C2_BARRIERSETC2_HPP
--- old/src/hotspot/share/opto/loopopts.cpp	2018-11-27 14:44:50.220418139 +0100
+++ new/src/hotspot/share/opto/loopopts.cpp	2018-11-27 14:44:44.651464237 +0100
@@ -887,6 +887,11 @@
 // Do the real work in a non-recursive function.  Data nodes want to be
 // cloned in the pre-order so they can feed each other nicely.
 Node *PhaseIdealLoop::split_if_with_blocks_pre( Node *n ) {
+  BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
+  Node* bs_res = bs->split_if_pre(this, n);
+  if (bs_res != NULL) {
+    return bs_res;
+  }
   // Cloning these guys is unlikely to win
   int n_op = n->Opcode();
   if( n_op == Op_MergeMem ) return n;