if (op instanceof OPT_StringConstantOperand) return VM_TypeReference.JavaLangString; else return op.asRegister().type;
return op.getType();
  private VM_TypeReference getRefTypeOf(OPT_Operand op) {    if (VM.VerifyAssertions) VM._assert(!op.isDefinitelyNull());    // op must be a RegisterOperand or StringConstantOperand    if (op instanceof OPT_StringConstantOperand)      return VM_TypeReference.JavaLangString;     else       return op.asRegister().type;  }