private boolean expectsBoxed(Call call, Node arg) {
// implicit this argument also is present
if (call.target() == arg)
return isBoxedType(call.target().type()); // targets of primitive types are unboxed
int i = call.arguments().indexOf(arg);
if (i < 0) throw new InternalCompilerError("BoxingPropagator: cannot find argument in call");
Type type = call.methodInstance().def().formalTypes().get(i).get();
return isBoxedType(type);
}