From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.stusta.mhn.de (mail.stusta.mhn.de [141.84.69.5]) by mail.openembedded.org (Postfix) with ESMTP id 7811B7F8E9 for ; Tue, 17 Sep 2019 08:16:11 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by mail.stusta.mhn.de (Postfix) with ESMTPSA id 46XbXq3FgZz3S; Tue, 17 Sep 2019 10:16:11 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=stusta.de; s=default; t=1568708171; bh=3vIOD1ezhjNzKDs5dqRShGcbeto4EPdtx5ga7WZLTvk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=a/0X3FRumhaMxrm68w/QbkwFJSZW1amuZsJJ7xNnHLeH5Dzbn1og3YLlYj+eZef2z jlv+EBJbj/xa2p1oQbS9Ki43CSMRnUSdNvoHRRVwMOLHpBRiJGRIK4nrtbnrWJgjvZ Zahzxbc8fyYc3PmS2HT5G9wennAKP/c95UOoggfS5Pa4Ns/i3O1bKMajR6aqXk4JkI q5Bd9ihwlRO+EE8gyB4+JhvFEsKZSZHcq2U1SWMVGjkKjNBWQPKSC3hKs9/1jFAV7Q 6os5GAQyjzNs9D+JxexP3G0Fk4/I1/pjMICXlg9MD5HasUTwkrl+7m1x2tkuTWzMMd 89H8VSYEAw5Jp2bG69wlN7+4pbjI8GxxC9QEXLaYUzoFcDAFoEhUJUwGQKft2tweub Ou3YzeZRSMZb52GSWGN3z/luPlqMhjC5gzVNp2raqwCn+1G+IYBofnjNenHrHncjuF pEcPqgddA1mj6SRYP3bzkPk+VywGac+a+JNRNMVly1NoPRpWESXBw2LPBlaMowUPeq 7L1Ru1bcFeETUm72lCJLACQs0k7W/L3YYRQ24yIPlXqBzIeEVcRGgdlrhO0GBhnpma IqWUxOVrW0ln4YwcSiU1IKiIZmTRsS+6C4sVegb47iLfpK0xtmOA6M1Is3Xj3iPDrY lxL++F0oaxP/Ehpq2Uyfn+Ns= Date: Tue, 17 Sep 2019 11:16:09 +0300 From: Adrian Bunk To: Andre McCurdy Message-ID: <20190917081609.GA11168@localhost> References: <20190916192429.27294-1-armccurdy@gmail.com> <20190916192429.27294-4-armccurdy@gmail.com> <0a559d39-3699-4504-addc-89fe7252fbea@Spark> <20190916223454.GA27980@localhost> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Cc: OE Core mailing list Subject: Re: [PATCH 4/8] ffmpeg: don't rely on configure to correctly detect ARM vfp or neon X-BeenThere: openembedded-core@lists.openembedded.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Patches and discussions about the oe-core layer List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Sep 2019 08:16:11 -0000 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit On Mon, Sep 16, 2019 at 03:43:42PM -0700, Andre McCurdy wrote: > On Mon, Sep 16, 2019 at 3:34 PM Adrian Bunk wrote: > > > > On Mon, Sep 16, 2019 at 03:08:01PM -0700, Andre McCurdy wrote: > > > On Mon, Sep 16, 2019 at 2:33 PM Christopher Larson wrote: > > > > > > > > This seems like something that could do with a ‘why’ in the commit message and/or comments, to me. > > > > > > To be consistent with: > > > > > > https://git.openembedded.org/openembedded-core/commit/?id=1a563214caf6bd5b3a026ebe953f8c692ebd640a > > >... > > > > libwebp sets -mfpu=neon when autodetecting, > > is there a similar problem with ffmpeg? > > > > > > +# Do not trust configure to determine if ARM vfp or neon are available. > > > > +# > > > > +EXTRA_OECONF_ARM = " \ > > > > + ${@bb.utils.contains('TUNE_FEATURES','vfp','--enable-vfp','--disable-vfp', d)} \ > > > > + ${@bb.utils.contains("TUNE_FEATURES",'neon','--enable-neon','--disable-neon',d)} \ > > >... > > > > If we cannot trust the vfp autodetection, why can we trust that the > > autodetection of the vfp variant (vfpv2, vfpv3 or vfpv3-d16) and > > the exact architecture (e.g. armv5te, armv6, armv6k or armv6t2) > > are correct? > > In general we can't. However these are all corner cases which are > rarely (if ever) tested. > > For ffmpeg configuring with --enable-runtime-cpudetect (which I think > we effectively do by default) probably hides a lot of the configure > time misdetection too. >... Building with --disable-runtime-cpudetect for qemuarmv5 gives: ARCH arm (armv5te) big-endian no runtime cpu detection no ARMv5TE enabled yes ARMv6 enabled yes ARMv6T2 enabled yes VFP enabled yes NEON enabled yes These 4 misdetections are all affecting a certain range of CPUs, ARMv6T2 misdetection should affect more CPUs than VFP misdetection. There likely is a common root cause that should be fixed, instead of manually specifying every autodetected feature. cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed