From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/2871 Path: news.gmane.org!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: Re: [PATCH] Added ARM optimised memcpy implementation Date: Fri, 1 Mar 2013 08:26:17 +0100 Message-ID: <20130301072617.GP6181@port70.net> References: <1362101090-8525-1-git-send-email-andre@bluewatersys.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 1362122791 18692 80.91.229.3 (1 Mar 2013 07:26:31 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 1 Mar 2013 07:26:31 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-2872-gllmg-musl=m.gmane.org@lists.openwall.com Fri Mar 01 08:26:55 2013 Return-path: 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 ) id 1UBKMk-0005ta-U9 for gllmg-musl@plane.gmane.org; Fri, 01 Mar 2013 08:26:51 +0100 Original-Received: (qmail 30189 invoked by uid 550); 1 Mar 2013 07:26:29 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 30179 invoked from network); 1 Mar 2013 07:26:29 -0000 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Xref: news.gmane.org gmane.linux.lib.musl.general:2871 Archived-At: * nwmcsween@gmail.com [2013-02-28 19:14:28 -0800]: > Hmm what does this do that builtins cannot? What I'm asking is why is this more preformant than preload + word-at-a-time. > musl uses naive memcpy if src and dst are not congruent (src%4 != dst%4) the android asm takes care of that by fetching a 32bytes from src into registers and dumping it into dst with apropriate shifts and in the congruent case 32byte alignment is used (cacheline aligned)