Hello Paul,

> (eval-and-compile
>   (defun my-func-eac (what)
>     (my-macro what)))
>
> (defun my-func-normal (what)
>   (my-macro what))
>
> (print (symbol-function 'my-func-eac))
> (print (symbol-function 'my-func-normal))
>
> `eval-and-compile' is advertised in Elisp manual to make
> byte-compilation of certain macros without prior loading
> possible. Looks strange that at the same time it can worsen
> performance of non-byte-compiled code.

Is the issue you want to draw attention to that an interpreted
`eval-and-compile' form doesn't macroexpand its body?

Michael.