From: David Miller <davem@davemloft.net>
To: dada1@cosmosbay.com
Cc: ak@suse.de, linux@horizon.com, akepner@sgi.com, netdev@vger.kernel.org
Subject: Re: [PATCH] NET : change layout of ehash table
Date: Fri, 09 Feb 2007 01:43:44 -0800 (PST) [thread overview]
Message-ID: <20070209.014344.63999119.davem@davemloft.net> (raw)
In-Reply-To: <200702091036.58474.dada1@cosmosbay.com>
From: Eric Dumazet <dada1@cosmosbay.com>
Date: Fri, 9 Feb 2007 10:36:58 +0100
> Thats strange, because pointer arithmetic is unsigned...
> I dont know when gcc started to use reciprocal division, maybe your gcc was
> very old ?
Yep, it was only on older gcc's.
And as the sparc gcc backend co-maintainer, I remember what the
problem was. The insn costs for multiply and divide were not set
properly on UltraSPARC, so it used the defaults, which made gcc think
divides were very cheap :-)
Current gcc does the right thing, even for weird sizes like 56 and 52
which expands to many IALU operations.
next prev parent reply other threads:[~2007-02-09 9:43 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-19 8:56 [PATCH] irlan: handle out of memory errors Akinobu Mita
2006-12-19 22:47 ` Samuel Ortiz
2007-02-07 8:12 ` David Miller
2007-02-07 10:59 ` [PATCH] NET : change layout of ehash table Eric Dumazet
2007-02-08 22:56 ` David Miller
2007-02-09 9:18 ` Andi Kleen
2007-02-09 8:40 ` David Miller
2007-02-09 8:57 ` Andi Kleen
2007-02-09 9:06 ` Eric Dumazet
2007-02-09 9:15 ` David Miller
2007-02-09 9:36 ` Eric Dumazet
2007-02-09 9:43 ` David Miller [this message]
2007-02-09 10:10 ` Andi Kleen
2007-02-09 17:44 ` [PATCH] NET : UDP can use sk_hash to speedup lookups Eric Dumazet
2007-02-09 23:45 ` David Miller
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=20070209.014344.63999119.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=ak@suse.de \
--cc=akepner@sgi.com \
--cc=dada1@cosmosbay.com \
--cc=linux@horizon.com \
--cc=netdev@vger.kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.