--- a/src/hotspot/share/opto/loopnode.cpp	Tue Jun 12 07:52:30 2018 -0700
+++ b/src/hotspot/share/opto/loopnode.cpp	Tue Jun 12 17:40:28 2018 +0200
@@ -25,6 +25,8 @@
 #include "precompiled.hpp"
 #include "ci/ciMethodData.hpp"
 #include "compiler/compileLog.hpp"
+#include "gc/shared/barrierSet.hpp"
+#include "gc/shared/c2/barrierSetC2.hpp"
 #include "libadt/vectset.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/resourceArea.hpp"
@@ -213,7 +215,8 @@
         if (nb_ctl_proj > 1) {
           break;
         }
-        assert(parent_ctl->is_Start() || parent_ctl->is_MemBar() || parent_ctl->is_Call(), "unexpected node");
+        assert(parent_ctl->is_Start() || parent_ctl->is_MemBar() || parent_ctl->is_Call() ||
+               BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(parent_ctl), "unexpected node");
         assert(idom(ctl) == parent_ctl, "strange");
         next = idom(parent_ctl);
       }
@@ -2635,7 +2638,7 @@
 //----------------------------build_and_optimize-------------------------------
 // Create a PhaseLoop.  Build the ideal Loop tree.  Map each Ideal Node to
 // its corresponding LoopNode.  If 'optimize' is true, do some loop cleanups.
-void PhaseIdealLoop::build_and_optimize(bool do_split_ifs, bool skip_loop_opts) {
+void PhaseIdealLoop::build_and_optimize(bool do_split_ifs, bool skip_loop_opts, bool last_round) {
   ResourceMark rm;
 
   int old_progress = C->major_progress();
@@ -2877,8 +2880,11 @@
   // that require basic-block info (like cloning through Phi's)
   if( SplitIfBlocks && do_split_ifs ) {
     visited.Clear();
-    split_if_with_blocks( visited, nstack );
+    split_if_with_blocks( visited, nstack, last_round );
     NOT_PRODUCT( if( VerifyLoopOptimizations ) verify(); );
+    if (last_round) {
+      C->set_major_progress();
+    }
   }
 
   if (!C->major_progress() && do_expensive_nodes && process_expensive_nodes()) {
@@ -4131,6 +4137,8 @@
     case Op_LoadL:
     case Op_LoadS:
     case Op_LoadP:
+    case Op_LoadBarrierSlowReg:
+    case Op_LoadBarrierWeakSlowReg:
     case Op_LoadN:
     case Op_LoadRange:
     case Op_LoadD_unaligned: