The Java bytecode stores it, however the Java language normally does not expose it. Having the compiler select the correct overload based on return type would most likely add a lot of complexity to the language itself ( have you seen the current overload resolution rules? ) without much benefit.

I think the compiler actually has to work around that when you narrow the return type of an overriden function: A method Object Base::get() overriden with Integer Child::get() will result in an additional compiler generated Object Child::get() in the bytecode.

The bytecode for method invocation does store the type of the method (which includes the return type), and it is quite valid for a class file to contain multiple methods that are only distinguishable by their return type. You can't normally do this visibly in Java, but I think it's used for bridge methods and a few other things by the compiler.