From mboxrd@z Thu Jan  1 00:00:00 1970
X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/3625
Path: news.gmane.org!not-for-mail
From: Rich Felker <dalias@aerifal.cx>
Newsgroups: gmane.linux.lib.musl.general
Subject: Re: Thinking about release
Date: Thu, 11 Jul 2013 00:33:48 -0400
Message-ID: <20130711043348.GM29800@brightrain.aerifal.cx>
References: <20130613012517.GA5859@brightrain.aerifal.cx>
 <CAPfzE3a0h=2NFqgnBqXj3J2q7VgYjqZ19Ab=0LAe5u5SvWXHaA@mail.gmail.com>
 <20130613014314.GC29800@brightrain.aerifal.cx>
 <CAPfzE3aerGrdmTkj15o0CTVtt8TZpTyAnSAj1Joau+Jb_cNGUA@mail.gmail.com>
 <20130709053711.GO29800@brightrain.aerifal.cx>
 <CAPfzE3ZTxynUeJjq7KWijZGhsV==NymW4vqLhnQbEYCXRxVf-g@mail.gmail.com>
 <CAL3m8eA-D==UjssLjxbFNpisQM=xaTo=KQHRmzcp1S-=XOnfOw@mail.gmail.com>
Reply-To: musl@lists.openwall.com
NNTP-Posting-Host: plane.gmane.org
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Trace: ger.gmane.org 1373517242 30119 80.91.229.3 (11 Jul 2013 04:34:02 GMT)
X-Complaints-To: usenet@ger.gmane.org
NNTP-Posting-Date: Thu, 11 Jul 2013 04:34:02 +0000 (UTC)
To: musl@lists.openwall.com
Original-X-From: musl-return-3629-gllmg-musl=m.gmane.org@lists.openwall.com Thu Jul 11 06:34:04 2013
Return-path: <musl-return-3629-gllmg-musl=m.gmane.org@lists.openwall.com>
Envelope-to: gllmg-musl@plane.gmane.org
Original-Received: from mother.openwall.net ([195.42.179.200])
	by plane.gmane.org with smtp (Exim 4.69)
	(envelope-from <musl-return-3629-gllmg-musl=m.gmane.org@lists.openwall.com>)
	id 1Ux8Zt-0004gU-IM
	for gllmg-musl@plane.gmane.org; Thu, 11 Jul 2013 06:34:01 +0200
Original-Received: (qmail 5531 invoked by uid 550); 11 Jul 2013 04:34:01 -0000
Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm
Precedence: bulk
List-Post: <mailto:musl@lists.openwall.com>
List-Help: <mailto:musl-help@lists.openwall.com>
List-Unsubscribe: <mailto:musl-unsubscribe@lists.openwall.com>
List-Subscribe: <mailto:musl-subscribe@lists.openwall.com>
Original-Received: (qmail 5523 invoked from network); 11 Jul 2013 04:34:00 -0000
Content-Disposition: inline
In-Reply-To: <CAL3m8eA-D==UjssLjxbFNpisQM=xaTo=KQHRmzcp1S-=XOnfOw@mail.gmail.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Xref: news.gmane.org gmane.linux.lib.musl.general:3625
Archived-At: <http://permalink.gmane.org/gmane.linux.lib.musl.general/3625>

On Wed, Jul 10, 2013 at 11:30:47PM -0500, Strake wrote:
> On 09/07/2013, Andre Renaud <andre@bluewatersys.com> wrote:
> > I wasn't too sure on memmove, but I've seen a reasonable amount of
> > code which just uses memmove as standard (rather than memcpy), to
> > avoid the possibility of overlapping regions. Not a great policy
> 
> Why? What loss with memmove? That it takes 1.0125 times as long as
> memcpy, other than when memcpy might just trash the array or summon
> nasal demons anyhow?

If you're performing a copy between objects that overlap, or if you're
not sure whether you might be, then it's very likely that you'd doing
something wrong. Or at least that's my opinion.

Anyway I have no objection to an optimized memmove, but I do think
starting with just memcpy is easier for review and
cleanup/optimization.

Rich