Subject: bug#64735: 29.0.92; find invocations are ~15x slower because of ignores

From: Eli Zaretskii <[email-masked]>
Date: Fri, 21 Jul 2023 15:46:26 +0300

> From: Ihor Radchenko <[email-masked]>
> Cc: [email-masked], Eli Zaretskii <[email-masked]>, [email-masked],
>  [email-masked]
> Date: Fri, 21 Jul 2023 12:25:29 +0000
> 
> Ihor Radchenko <[email-masked]> writes:
> 
> > The question is: what is more costly
> > (a) matching complex regexp && call function or
> > (b) call function (lambda (fn) (when (and foo (match-string- ... fn)) ...))
> 
> (benchmark-run-compiled 10000000 (string-match-p (caar file-name-handler-alist) "/path/to/very/deep/file"))
> ;; => (1.495432981 0 0.0)
> (benchmark-run-compiled 10000000 (funcall (lambda (fn) (and nil (string-match-p (caar file-name-handler-alist) fn))) "/path/to/very/deep/file"))
> ;; => (0.42053276500000003 0 0.0)
> 
> Looks like even funcall overheads are not as bad as invoking regexp search.

But "nil" is not a faithful emulation of the real test which will have
to be put there, is it?