unofficial mirror of guile-devel@gnu.org 
 help / color / mirror / Atom feed
From: Andy Wingo <wingo@pobox.com>
To: ludo@gnu.org (Ludovic Courtès)
Cc: guile-devel@gnu.org
Subject: Re: Optimizing ‘string=’
Date: Tue, 22 Jun 2010 23:54:38 +0200	[thread overview]
Message-ID: <m339we91i9.fsf@pobox.com> (raw)
In-Reply-To: <87eifyhhxg.fsf@gnu.org> ("Ludovic Courtès"'s message of "Tue, 22 Jun 2010 23:32:43 +0200")

Greets,

On Tue 22 Jun 2010 23:32, ludo@gnu.org (Ludovic Courtès) writes:

> Andy Wingo <wingo@pobox.com> writes:
>
>> Nasty, but OK I guess if you need it. Why not also add a fast path for
>> scm_is_eq (s1, s2), or for comparing stringbufs, or something ?
>
> Hmm yes.  Though if there are too many fast paths the whole thing ends
> up being slow.  ;-)

> I don’t expect (eq? s1 s2) and (eq? (string-buf s1) (string-buf s2)) to
> be common enough to warrant a more specific special case, though.

Does it affect your original case at all?. In any event, it doesn't
involve a memory dereference, only a branch. It's a cheap check.

> Because it’s a top-level program, “string=” is looked up at each
> iteration.

Ah, right. Thanks for the explanation :)

Andy
-- 
http://wingolog.org/



  reply	other threads:[~2010-06-22 21:54 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-22 19:40 Optimizing ‘string=’ Ludovic Courtès
2010-06-22 20:43 ` Ludovic Courtès
2010-06-23  2:25   ` Mike Gran
2010-06-22 20:51 ` Andy Wingo
2010-06-22 21:32   ` Ludovic Courtès
2010-06-22 21:54     ` Andy Wingo [this message]
2010-07-02 13:32       ` Ludovic Courtès

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/guile/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=m339we91i9.fsf@pobox.com \
    --to=wingo@pobox.com \
    --cc=guile-devel@gnu.org \
    --cc=ludo@gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).