From: Arnd Bergmann <arnd@arndb.de>
To: Nathan Chancellor <natechancellor@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
James Y Knight <jyknight@google.com>,
clang-built-linux@googlegroups.com,
"# 3.4.x" <stable@vger.kernel.org>
Subject: Re: [PATCH] Makefile: Add '-fno-builtin-bcmp' to CLANG_FLAGS
Date: Wed, 13 Mar 2019 14:48:49 +0100 [thread overview]
Message-ID: <CAK8P3a344k=MDAX-d21U4+H+mv7Vcd9YhAN4NPEJm1CXv76tkw@mail.gmail.com> (raw)
In-Reply-To: <20190313134447.GA19066@archlinux-ryzen>
On Wed, Mar 13, 2019 at 2:44 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
> On Wed, Mar 13, 2019 at 09:13:11AM +0100, Rasmus Villemoes wrote:
> > Wouldn't it be better to just define bcmp as an alias for memcmp? They
> > seem to have compatible prototypes, and then somebody might someday sit
> > down and implement some word-at-a-time version of bcmp making use of the
> > weaker guarantees about the return value to gain some performance. But I
> > suppose that can also be done later.
>
> Thank you much for the review, I didn't even realize this was possible :)
>
> I'd certainly like to explore it as that is what glibc does. How would
> you suggest going about it here?
I suggested a possible implementation (likely contains bugs) and
an alias for architectures that require strict alignment, see
https://bugs.llvm.org/show_bug.cgi?id=41035#c11
We could start out with just the alias.
Arnd
next prev parent reply other threads:[~2019-03-13 13:49 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-12 21:52 [PATCH] Makefile: Add '-fno-builtin-bcmp' to CLANG_FLAGS Nathan Chancellor
2019-03-12 22:55 ` Nick Desaulniers
2019-03-13 8:13 ` Rasmus Villemoes
2019-03-13 10:58 ` Masahiro Yamada
2019-03-13 13:44 ` Nathan Chancellor
2019-03-13 13:48 ` Arnd Bergmann [this message]
2019-03-13 15:32 ` Nathan Chancellor
2019-03-13 17:21 ` Nick Desaulniers
2019-03-13 17:27 ` Nick Desaulniers
2019-03-13 18:02 ` [PATCH] lib/string.c: implement a basic bcmp Nick Desaulniers
2019-03-13 18:11 ` Nick Desaulniers
2019-03-13 18:17 ` [PATCH v2] " Nick Desaulniers
2019-03-13 18:40 ` Steven Rostedt
2019-03-13 18:51 ` Nick Desaulniers
2019-03-13 19:01 ` Steven Rostedt
2019-03-13 19:34 ` Rasmus Villemoes
2019-03-13 20:12 ` Steven Rostedt
2019-03-13 20:37 ` [PATCH v3] " Nick Desaulniers
2019-03-13 21:03 ` Steven Rostedt
2019-03-13 21:13 ` [PATCH v4] " Nick Desaulniers
2019-03-14 3:15 ` Nathan Chancellor
2019-03-14 5:00 ` Masahiro Yamada
2019-03-14 8:33 ` Andy Shevchenko
2019-03-14 9:57 ` David Laight
2019-03-14 11:07 ` Rasmus Villemoes
2019-03-21 2:11 ` Andrew Morton
2019-03-21 17:02 ` Nick Desaulniers
2019-03-21 17:20 ` Nick Desaulniers
2019-03-21 21:05 ` Andrew Morton
2019-03-22 7:17 ` Rasmus Villemoes
2019-03-22 7:43 ` Sedat Dilek
2019-03-13 19:38 ` [PATCH] Makefile: Add '-fno-builtin-bcmp' to CLANG_FLAGS Arnd Bergmann
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='CAK8P3a344k=MDAX-d21U4+H+mv7Vcd9YhAN4NPEJm1CXv76tkw@mail.gmail.com' \
--to=arnd@arndb.de \
--cc=clang-built-linux@googlegroups.com \
--cc=jyknight@google.com \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=michal.lkml@markovi.net \
--cc=natechancellor@gmail.com \
--cc=ndesaulniers@google.com \
--cc=stable@vger.kernel.org \
--cc=yamada.masahiro@socionext.com \
/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).