From: Peter Zijlstra <peterz@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>,
LKML <linux-kernel@vger.kernel.org>,
Jamie Lokier <jamie@shareable.org>,
Roland Dreier <rdreier@cisco.com>,
Al Viro <viro@ZenIV.linux.org.uk>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 2/5] bitops: compile time optimization for hweight_long(CONSTANT)
Date: Wed, 03 Feb 2010 16:15:57 +0100 [thread overview]
Message-ID: <1265210157.24455.646.camel@laptop> (raw)
In-Reply-To: <20100203070825.e36b3932.akpm@linux-foundation.org>
On Wed, 2010-02-03 at 07:08 -0800, Andrew Morton wrote:
> On Wed, 3 Feb 2010 21:39:51 +0800 Wu Fengguang <fengguang.wu@intel.com> wrote:
>
> > Is there an official lowest GCC version that Linux supports?
>
> Documentation/Changes says gcc-3.2.
Anyway, its not like that macro I used isn't straight forward. Not much
a builtin can do better.
The only benefit the builtin has is possibly use machine popcnt
instructions but we already deal with that in the kernel.
next prev parent reply other threads:[~2010-02-03 15:16 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-30 9:45 [PATCH 0/5] [RESEND] FMODE_NONOTIFY and FMODE_NEG_OFFSET bits Wu Fengguang
2010-01-30 9:45 ` [PATCH 1/5] fanotify: fix FMODE_NONOTIFY bit number Wu Fengguang
2010-02-01 20:44 ` Andrew Morton
2010-01-30 9:45 ` [PATCH 2/5] bitops: compile time optimization for hweight_long(CONSTANT) Wu Fengguang
2010-02-01 20:48 ` Andrew Morton
2010-02-03 13:39 ` Wu Fengguang
2010-02-03 15:08 ` Andrew Morton
2010-02-03 15:15 ` Peter Zijlstra [this message]
2010-02-03 15:42 ` Andrew Morton
2010-02-03 15:47 ` Peter Zijlstra
2010-02-03 17:11 ` H. Peter Anvin
2010-02-03 18:14 ` Borislav Petkov
2010-02-03 18:47 ` Peter Zijlstra
2010-02-03 19:49 ` H. Peter Anvin
2010-02-04 15:10 ` Borislav Petkov
2010-02-04 15:13 ` Peter Zijlstra
2010-02-04 15:54 ` Borislav Petkov
2010-02-04 16:04 ` Peter Zijlstra
2010-02-05 12:11 ` Borislav Petkov
2010-02-05 12:14 ` Peter Zijlstra
2010-02-05 21:54 ` H. Peter Anvin
2010-02-06 9:36 ` Borislav Petkov
2010-02-07 1:55 ` H. Peter Anvin
2010-02-08 9:28 ` Borislav Petkov
2010-02-08 9:35 ` H. Peter Anvin
2010-02-08 9:59 ` Borislav Petkov
2010-02-11 17:24 ` Borislav Petkov
2010-02-11 17:33 ` H. Peter Anvin
2010-02-12 17:06 ` Borislav Petkov
2010-02-12 17:28 ` H. Peter Anvin
2010-02-12 17:47 ` Borislav Petkov
2010-02-12 19:05 ` H. Peter Anvin
2010-02-17 13:57 ` Michal Marek
2010-02-17 17:20 ` Borislav Petkov
2010-02-17 17:31 ` Michal Marek
2010-02-17 17:34 ` Borislav Petkov
2010-02-17 17:39 ` Michal Marek
2010-02-18 6:19 ` Borislav Petkov
2010-02-19 14:22 ` [PATCH] x86: Add optimized popcnt variants Borislav Petkov
2010-02-19 16:06 ` H. Peter Anvin
2010-02-19 16:45 ` Borislav Petkov
2010-02-19 16:53 ` H. Peter Anvin
2010-02-22 14:17 ` Borislav Petkov
2010-02-22 17:21 ` H. Peter Anvin
2010-02-22 18:49 ` Borislav Petkov
2010-02-22 19:55 ` H. Peter Anvin
2010-02-23 6:37 ` Borislav Petkov
2010-02-23 15:58 ` Borislav Petkov
2010-02-23 17:34 ` H. Peter Anvin
2010-02-23 17:54 ` Borislav Petkov
2010-02-23 18:17 ` H. Peter Anvin
2010-02-23 19:06 ` Borislav Petkov
2010-02-26 5:27 ` H. Peter Anvin
2010-02-26 7:47 ` Borislav Petkov
2010-02-26 17:48 ` H. Peter Anvin
2010-02-27 8:28 ` Borislav Petkov
2010-02-27 20:00 ` H. Peter Anvin
2010-03-09 15:36 ` Borislav Petkov
2010-03-09 15:50 ` Peter Zijlstra
2010-03-09 16:23 ` Borislav Petkov
2010-03-09 16:32 ` Peter Zijlstra
2010-03-09 17:32 ` Borislav Petkov
2010-03-09 17:37 ` Peter Zijlstra
2010-03-18 11:17 ` Borislav Petkov
2010-03-18 11:19 ` [PATCH 1/2] bitops: Optimize hweight() by making use of compile-time evaluation Borislav Petkov
2010-03-18 11:20 ` [PATCH 2/2] x86: Add optimized popcnt variants Borislav Petkov
2010-02-18 10:51 ` [PATCH 2/5] bitops: compile time optimization for hweight_long(CONSTANT) Peter Zijlstra
2010-02-18 11:51 ` Borislav Petkov
2010-02-14 10:12 ` Peter Zijlstra
2010-02-14 11:24 ` Borislav Petkov
2010-02-14 12:23 ` Peter Zijlstra
2010-02-14 14:19 ` Borislav Petkov
2010-02-14 18:36 ` H. Peter Anvin
2010-02-14 20:28 ` Borislav Petkov
2010-02-14 22:13 ` H. Peter Anvin
2010-02-04 15:16 ` H. Peter Anvin
2010-02-04 15:39 ` Brian Gerst
2010-02-03 17:10 ` H. Peter Anvin
2010-01-30 9:45 ` [PATCH 3/5] vfs: O_* bit numbers uniqueness check Wu Fengguang
2010-01-30 9:45 ` [PATCH 4/5] vfs: introduce FMODE_NEG_OFFSET for allowing negative f_pos Wu Fengguang
2010-01-30 9:45 ` [PATCH 5/5] devmem: dont allow seek to last page Wu Fengguang
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=1265210157.24455.646.camel@laptop \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=fengguang.wu@intel.com \
--cc=hpa@zytor.com \
--cc=jamie@shareable.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=rdreier@cisco.com \
--cc=viro@ZenIV.linux.org.uk \
/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).