Comment by kazinator

You can declaim inline a toplevel function. That doesn't necessarily mean that it will be integrated into callers. Among the possible effects is that the dynamism of reference can be culled away. If a function A calls B where B is declaimed inline then A can be compiled to assume that B definition. (Such that if B is redefined at run-time, A can keep calling the old B, not going through the #'B function binding lookup.).

I seem to remember that Common Lisp compilers are allowed to do this for functions that are in the same file even if they are not declaimed inline. If A and B are in the same file, and B is not declaimed notinline (the opposite of inline), then A can be translated to assume the B definition.

So all your helper functions in a Lisp module are allowed to be called more efficiently, not having to go through the function binding of the symbol.