From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.pbcl.net ([88.198.119.4] helo=hetzner.pbcl.net) by linuxtogo.org with esmtp (Exim 4.72) (envelope-from ) id 1QtyUh-0008NU-Cg for openembedded-core@lists.openembedded.org; Thu, 18 Aug 2011 11:02:31 +0200 Received: from elite.brightsigndigital.co.uk ([81.142.160.137] helo=[172.30.1.145]) by hetzner.pbcl.net with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1QtyQ6-0000aB-CC for openembedded-core@lists.openembedded.org; Thu, 18 Aug 2011 10:57:46 +0200 From: Phil Blundell To: Patches and discussions about the oe-core layer Date: Thu, 18 Aug 2011 09:57:45 +0100 In-Reply-To: <4E4CAE28.8050600@linux.intel.com> References: <4E4CAE28.8050600@linux.intel.com> X-Mailer: Evolution 3.0.2- Message-ID: <1313657866.6733.237.camel@phil-desktop> Mime-Version: 1.0 Subject: Re: [PATCH][RFC] cortexa8: use hard floating point 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: Thu, 18 Aug 2011 09:02:31 -0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit On Wed, 2011-08-17 at 23:16 -0700, Darren Hart wrote: > From what I could gather, it makes sense to address using mfloat-abi=hard > for the beagleboard in the cortexa8 tune file. Before I submit this as a pull > request, I'd appreciate a sanity check from the Beagleboard experts. > >[...] > > mfloat-abi is currently set to soft for beagleboard (cortexa8) and needs to be > set to hard to take advantage of the floating point hardware. Have you benchmarked this change? It isn't really true to say that hf needs to be set to "take advantage" of the FP hardware; you will still get most of the benefit of the VFP without it. I would be surprised if this made much of a difference on any real-world workload. Changing -mfloat-abi is (obviously) an ABI change and is definitely not the sort of thing to do capriciously. If you apply the patch in its current form then it will make cortexa8 binaries incompatible with everything else by default, which is probably not going to be a good thing. I think this ought to be a DISTRO choice not a machine one. p.