looking-at-p slower than looking-at

[Nicolas Richard]

Marcin Borkowski <mbork@mbork.pl> writes:

> You might also (depending on your use-case) want to use looking-at-p,
> which is marginally slower than looking-at, but does not modify match
> data.

Why is it slower and how much slower is it ? I don't see how it can
happen from its implementation:

(defsubst looking-at-p (regexp)
  "\
Same as `looking-at' except this function does not change the match data."
  (let ((inhibit-changing-match-data t))
    (looking-at regexp)))

thanks,

-- 
Nico.