If you want to generate f1 and f2 "as is" then you need to make them to be entry points, that is,
codegen f1 -args {f1's args here} ...
codegen f2 -args {f2's args here} ...
or you can do in one go:
codegen f1 -args {...} f2 -args {...}
or you can also add top
codegen f1 -args {...} f2 -args {...} top -args {top's args}
There is no reliable way to generate code for top() as an entry point without f1, f2 being entry point as well, and have f1 and f2 have exactly the right signatures that you want.
