You can't really have bytecode instructions for the vector API functions because they're generic. They're instead methods, which the JIT compiler can handle specially if it so chooses to. Effectively, for pure computational operations (i.e. not ones doing complex stack operations or jumps), there's no real difference between a method call and a new bytecode (except that adding a new bytecode is a lot more work because everything must be updated to support it, whereas a new method is just a new method).