--- old/src/share/vm/opto/split_if.cpp	2015-10-08 22:15:55.363120217 +0200
+++ new/src/share/vm/opto/split_if.cpp	2015-10-08 22:15:55.314121388 +0200
@@ -32,6 +32,7 @@
 //------------------------------split_thru_region------------------------------
 // Split Node 'n' through merge point.
 Node *PhaseIdealLoop::split_thru_region( Node *n, Node *region ) {
+  assert(n->Opcode() != Op_ShenandoahWriteBarrier, "not with write barriers");
   uint wins = 0;
   assert( n->is_CFG(), "" );
   assert( region->is_Region(), "" );
@@ -73,7 +74,8 @@
   if( n->is_Phi() ) return false; // Local PHIs are expected
 
   // Recursively split-up inputs
-  for (uint i = 1; i < n->req(); i++) {
+  uint first_input = n->Opcode() == Op_ShenandoahWBMemProj ? 0 : 1;
+  for (uint i = first_input; i < n->req(); i++) {
     if( split_up( n->in(i), blk1, blk2 ) ) {
       // Got split recursively and self went dead?
       if (n->outcnt() == 0)
@@ -216,6 +218,7 @@
   register_new_node(phi, blk1);
 
   // Remove cloned-up value from optimizer; use phi instead
+  split_mem_thru_phi(n, blk1, phi);
   _igvn.replace_node( n, phi );
 
   // (There used to be a self-recursive call to split_up() here,