VM_Atom a = (VM_Atom)Htype;
String a = (String)Htype;
  private void phiHelper (OPT_Instruction s, OPT_BasicBlock b) {    // for phi function, we dont' register implicit defs and uses    // since they're explicit in the instruction    /*    Object result = Phi.getResult(s);    if (!(result instanceof OPT_HeapOperand))      return;    OPT_HeapOperand H = (OPT_HeapOperand)Phi.getResult(s);    Object Htype = H.getHeapType();    if (Htype instanceof VM_Type) {      VM_Type t = (VM_Type)Htype;      registerDef(s, b, t);    }     else if (Htype instanceof VM_Field) {      VM_Field f = (VM_Field)Htype;      registerDef(s, b, f);    }    else {      VM_Atom a = (VM_Atom)Htype;      registerDef(s, b, a);    }    for (int i = 0; i < Phi.getNumberOfValues(s); i++) {      OPT_HeapOperand U = (OPT_HeapOperand)Phi.getValue(s, i);      Object Utype = U.getHeapType();      if (Utype instanceof VM_Type) {        VM_Type t = (VM_Type)Utype;        registerUse(s, t);      }       else if (Utype instanceof VM_Field) {        VM_Field f = (VM_Field)Utype;        registerUse(s, f);      } else {        VM_Atom a = (VM_Atom)Utype;        registerUse(s, a);      }    }  */  }