From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yi0-f47.google.com ([209.85.218.47]) by linuxtogo.org with esmtp (Exim 4.72) (envelope-from ) id 1QwGAV-0000t5-3v for openembedded-core@lists.openembedded.org; Wed, 24 Aug 2011 18:19:07 +0200 Received: by yia28 with SMTP id 28so953307yia.6 for ; Wed, 24 Aug 2011 09:14:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=cvuHzAt/TB0eWkJVkZo0ccOa9RLc+s2pxT6eIwHAuy0=; b=QzYBq9u2NpD2omiiS7Ks7Dv7HEk7fTK18UAbln1WJgzmW+W9BcoaTWy5HctW0s9f2X zV/w0BG0sik1fwSqeFnG6NTot3ycNDSh9Ov3Bh958rrwS59oC9htJ1T+tkTWDNOoNUmQ fOL6G4w4zWUosZh7/2vNKY8ua/89IfFFRaHAI= Received: by 10.101.54.20 with SMTP id g20mr5076299ank.69.1314202459540; Wed, 24 Aug 2011 09:14:19 -0700 (PDT) Received: from [192.168.1.70] (99-57-141-118.lightspeed.sntcca.sbcglobal.net [99.57.141.118]) by mx.google.com with ESMTPS id v6sm1011556anq.28.2011.08.24.09.14.18 (version=SSLv3 cipher=OTHER); Wed, 24 Aug 2011 09:14:18 -0700 (PDT) Message-ID: <4E552357.3070609@gmail.com> Date: Wed, 24 Aug 2011 09:14:15 -0700 From: Khem Raj User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:6.0) Gecko/20110812 Thunderbird/6.0 MIME-Version: 1.0 To: openembedded-core@lists.openembedded.org References: <0597F428-97F2-461F-804B-FE793E911BD4@kernel.crashing.org> <1314183168.19905.6.camel@phil-desktop> In-Reply-To: <1314183168.19905.6.camel@phil-desktop> Subject: Re: why do we poison -Os? X-BeenThere: openembedded-core@lists.openembedded.org X-Mailman-Version: 2.1.11 Precedence: list Reply-To: Patches and discussions about the oe-core layer List-Id: Patches and discussions about the oe-core layer List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Aug 2011 16:19:07 -0000 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit On 8/24/2011 3:52 AM, Phil Blundell wrote: > On Wed, 2011-08-24 at 09:47 +0800, Xu, Dongxiao wrote: >> My understanding is that, if GCC is not configured with the ability of code space optimization, target recipes will not have code size benefit even if adding "-Os" option. > > No, that's incorrect. All that --enable-target-optspace does is change > the definition of CFLAGS_FOR_TARGET, which causes the GCC support > libraries (i.e. libgcc, libstdc++, etc) to be built with -Os rather than > -O2. It has no effect on the functionality of the compiler itself. > thats correct. this options is only for making gcc runtime to be built with Os. It does not make gcc to use -Os by default. The problem for ppc however is that if you built with Os then gcc depends upon functions from libgcc.a which needs libgcc.so to be a linker script stub rather than a symlink as it used to be but this has been fixed > p. > > > > _______________________________________________ > Openembedded-core mailing list > Openembedded-core@lists.openembedded.org > http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/openembedded-core