From: David Miller <davem@davemloft.net>
To: torvalds@linux-foundation.org
Cc: linux-arch@vger.kernel.org
Subject: Re: Mostly portable strnlen_user()
Date: Fri, 25 May 2012 19:41:25 -0400 (EDT) [thread overview]
Message-ID: <20120525.194125.1593753424815090718.davem@davemloft.net> (raw)
In-Reply-To: <CA+55aFxyno-mCNsJZzpW+5HAc0KA477ZeHGZ6=ONLcnHWiHaEA@mail.gmail.com>
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 25 May 2012 16:37:40 -0700
> On Fri, May 25, 2012 at 4:14 PM, David Miller <davem@davemloft.net> wrote:
>>
>> I suppose then I'd need to make BE's has_zero() a macro instead of a
>> function. Either that or we pass a pointer to this opaque typedef
>> thing.
>
> Gcc is *usually* pretty good about optimizing small structures on the
> stack, even if you pass a pointer (if the pointer then always gets
> dereferenced within that function). So I think you could try the
> "pointer to opaque thing" approach and see.
>
> But yeah, the macro approach obviously puts much less reliance on the
> optimizer getting things right, so it might be the way to go if it
> turns out that gcc screws up code generation.
I'm playing around with this now, I should have something for you
to look at in the next few hours.
next prev parent reply other threads:[~2012-05-25 23:41 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-25 22:35 Mostly portable strnlen_user() Linus Torvalds
2012-05-25 23:06 ` David Miller
2012-05-25 23:11 ` Linus Torvalds
2012-05-25 23:14 ` David Miller
2012-05-25 23:37 ` Linus Torvalds
2012-05-25 23:41 ` David Miller [this message]
2012-05-26 0:41 ` David Miller
2012-05-26 1:09 ` Linus Torvalds
2012-05-26 1:21 ` David Miller
2012-05-26 2:13 ` Linus Torvalds
2012-05-26 2:43 ` David Miller
2012-05-26 3:56 ` Linus Torvalds
2012-05-26 4:15 ` David Miller
2012-05-26 4:19 ` Linus Torvalds
2012-05-26 4:34 ` David Miller
2012-05-26 4:44 ` David Miller
2012-05-26 5:06 ` Linus Torvalds
2012-05-26 5:59 ` David Miller
2012-05-26 8:32 ` Jonas Bonn
2012-05-26 18:39 ` Linus Torvalds
2012-05-26 23:46 ` David Miller
2012-05-27 8:28 ` Jonas Bonn
2012-05-28 3:07 ` Paul Mackerras
2012-05-28 3:47 ` Linus Torvalds
2012-05-28 3:53 ` Linus Torvalds
2012-05-26 4:16 ` Linus Torvalds
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=20120525.194125.1593753424815090718.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=linux-arch@vger.kernel.org \
--cc=torvalds@linux-foundation.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 NNTP newsgroup(s).