src/share/vm/opto/loopTransform.cpp

*** 925,934 ****
--- 925,935 ----
  
    Node *x = NULL;               // If required, a clone of 'n'
    // Check for 'n' being pinned in the backedge.
    if( n->in(0) && n->in(0) == back_ctrl ) {
      assert(clones.find(n->_idx) == NULL, "dead loop");
+     assert(n->Opcode() != Op_ShenandoahWriteBarrier, "no wbs yet");
      x = n->clone();             // Clone a copy of 'n' to preheader
      clones.push(x, n->_idx);
      x->set_req( 0, preheader_ctrl ); // Fix x's control input to preheader
    }