From: Noah Goldstein <goldstein.w.n@gmail.com>
To: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
Cc: GNU C Library <libc-alpha@sourceware.org>
Subject: Re: [PATCH 3/7] Remove atomic_bit_set/bit_test_set
Date: Wed, 6 Jul 2022 12:51:46 -0700 [thread overview]
Message-ID: <CAFUsyf+H5A1NqTBxwvvfVd7TzXJ8-J8HtUmUg8P9KVwEQYk9SQ@mail.gmail.com> (raw)
In-Reply-To: <AM5PR0801MB1668B2BB6C6560CCA3BA5E3083809@AM5PR0801MB1668.eurprd08.prod.outlook.com>
On Wed, Jul 6, 2022 at 12:37 PM Wilco Dijkstra <Wilco.Dijkstra@arm.com> wrote:
>
> Hi Noah,
>
> > For non-constant shift values it needs to be like atomic_or4/atomic_or5.
> >
> > Since this needs to be set up in a particular way it seems worth it to
> > keep it as a macro that will do it properly. Fine with replacing the underlying
> > atomic op with a compiler intrinsic.
>
> This was only one use in GLIBC so how does adding a private macro help other
> software? This idiom doesn't appear common, particularly with a non-constant bit,
> but in principle the compiler could be fixed so that it optimizes do_atomic_or2/3
> as well.
The usage in this patch is fine. Just seems having an internal API for
it provides
value given that in the future there may be a need for atomic_bit_set
w.o a constant
bit and there are non-obvious tricks necessary for doing it right.
>
> Cheers,
> Wilco
next prev parent reply other threads:[~2022-07-06 19:51 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-06 15:14 Wilco Dijkstra
2022-07-06 16:14 ` Noah Goldstein
2022-07-06 18:25 ` Noah Goldstein
2022-07-06 18:59 ` Wilco Dijkstra
2022-07-06 19:14 ` Noah Goldstein
2022-07-06 19:30 ` H.J. Lu
2022-07-06 19:36 ` Wilco Dijkstra
2022-07-06 19:51 ` Noah Goldstein [this message]
2022-07-06 19:56 ` Noah Goldstein
2022-07-06 20:14 ` Wilco Dijkstra
2022-07-06 20:30 ` Noah Goldstein
2022-07-06 20:56 ` H.J. Lu
2022-07-12 17:47 ` Adhemerval Zanella Netto
2022-07-12 18:09 ` H.J. Lu
2022-07-12 18:44 ` Wilco Dijkstra
2022-07-12 19:11 ` H.J. Lu
2022-07-12 19:18 ` Noah Goldstein
2022-07-12 20:39 ` Wilco Dijkstra
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
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAFUsyf+H5A1NqTBxwvvfVd7TzXJ8-J8HtUmUg8P9KVwEQYk9SQ@mail.gmail.com \
--to=goldstein.w.n@gmail.com \
--cc=Wilco.Dijkstra@arm.com \
--cc=libc-alpha@sourceware.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).