Re: Patch: Syntax and Hard Newlines

[Richard Stallman]

          (setq parse-sexp-lookup-properties t
                old-time (current-time))
          (emacs-lisp-mode)
          (setq time-diff (time-subtract (current-time)
                                         old-time))))

I don't think that is a real test, because merely enabling Emacs Lisp
mode does not parse anything.  You need to do some parsing
across the buffer.