From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 63.mail-out.ovh.net ([91.121.185.56]) by linuxtogo.org with smtp (Exim 4.69) (envelope-from ) id 1PE5Gy-0003Kv-K5 for openembedded-devel@lists.openembedded.org; Thu, 04 Nov 2010 20:14:57 +0100 Received: (qmail 17508 invoked by uid 503); 4 Nov 2010 19:43:50 -0000 Received: from b9.ovh.net (HELO mail239.ha.ovh.net) (213.186.33.59) by 63.mail-out.ovh.net with SMTP; 4 Nov 2010 19:43:50 -0000 Received: from b0.ovh.net (HELO queueout) (213.186.33.50) by b0.ovh.net with SMTP; 4 Nov 2010 21:14:06 +0200 Received: from tal33-3-82-233-81-124.fbx.proxad.net (HELO ?192.168.2.15?) (ebenard%eukrea.com@82.233.81.124) by ns0.ovh.net with SMTP; 4 Nov 2010 21:14:05 +0200 Message-ID: <4CD305FC.7070305@eukrea.com> Date: Thu, 04 Nov 2010 20:14:04 +0100 From: =?UTF-8?B?RXJpYyBCw6luYXJk?= User-Agent: Mozilla/5.0 (X11; U; Linux i686; fr; rv:1.9.2.12) Gecko/20101027 Thunderbird/3.1.6 MIME-Version: 1.0 To: openembedded-devel@lists.openembedded.org References: <1288864342-20973-1-git-send-email-eric@eukrea.com> <4CD2FAF0.4080905@freyther.de> In-Reply-To: <4CD2FAF0.4080905@freyther.de> X-Ovh-Tracer-Id: 431219664836406601 X-Ovh-Remote: 82.233.81.124 (tal33-3-82-233-81-124.fbx.proxad.net) X-Ovh-Local: 213.186.33.20 (ns0.ovh.net) X-SA-Exim-Connect-IP: 91.121.185.56 X-SA-Exim-Mail-From: eric@eukrea.com X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on discovery X-Spam-Level: X-Spam-Status: No, score=-2.6 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.2.5 X-SA-Exim-Version: 4.2.1 (built Wed, 25 Jun 2008 17:20:07 +0000) X-SA-Exim-Scanned: Yes (on linuxtogo.org) Subject: Re: [PATCH/RFC] qt4-embedded: tune QT_ARCH for armv6 X-BeenThere: openembedded-devel@lists.openembedded.org X-Mailman-Version: 2.1.11 Precedence: list Reply-To: openembedded-devel@lists.openembedded.org List-Id: Using the OpenEmbedded metadata to build Distributions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Nov 2010 19:14:57 -0000 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi, Le 04/11/2010 19:26, Holger Freyther a écrit : > On 11/04/2010 10:52 AM, Eric Bénard wrote: >> this is a RFC, I think it can also be used on qt 4.6.x and on armv7. >> Setting QT_ARCH to armv6 enable some asm optimized functions in QT. > > Do you know the consequences of this change? E.g. in the painting > engine unaligned memory access will be allowed. I am not sure that Nokia has > ever benchmarked what is faster (aligned/unaligned) access. So it would be > very interesting to know the perf difference. E.g. use qttracereply to measure it. > > Phil do you happen to know why unaligned access got allowed starting from > armv6? How fast will it be? > in the painting engine, from what I saw in the .h, the asm optimisations are only enabled when using ARM RCVT compiler and not when using gcc but I have not checked everywhere in the code so I'm not sure of this. Eric