src/share/vm/opto/superword.cpp

*** 63,72 ****
--- 63,77 ----
  
    // Check for no control flow in body (other than exit)
    Node *cl_exit = cl->loopexit();
    if (cl_exit->in(0) != lpt->_head) return;
  
+   // Make sure the are no extra control users of the loop backedge
+   if (cl->back_control()->outcnt() != 1) {
+     return;
+   } 
+ 
    // Check for pre-loop ending with CountedLoopEnd(Bool(Cmp(x,Opaque1(limit))))
    CountedLoopEndNode* pre_end = get_pre_loop_end(cl);
    if (pre_end == NULL) return;
    Node *pre_opaq1 = pre_end->limit();
    if (pre_opaq1->Opcode() != Op_Opaque1) return;