From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Subject: Re: Testsuite failures on sparc64 due to unaligned access since 1.5.0 Date: Fri, 11 Dec 2020 09:41:58 -0500 Message-ID: <20201211144158.GX32272@bill-the-cat> References: <10d4dbcb-506c-df88-cd71-f3ad27254341@physik.fu-berlin.de> <4e3cdb1c-87c4-810b-513d-eaae64456d36@physik.fu-berlin.de> <20201211010739.GB4874@yekko.fritz.box> <3b237853-dd8c-99b7-e258-7c51e9970560@physik.fu-berlin.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="9OC2iooDHtHJ1Xen" Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=konsulko.com; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=d7jIkTA53ONtVp84vYhVQU2rrFVELCGZFTTrNdjDGLk=; b=NG4+OOYgOGxUn1JwTlvj7S06CT+a1JWtw6I3CB6eszAbEuYzq6V09Y/ZJ8uttBPgsA kPM9l4fLPBnMrLb5ViHY8y2J/KtUKi/S7AeStx1zPGJ9xJ77oYc+wxuKkE7/a1W2k5s7 0q5m/GBmIzs1jCEnHmKTDwZsAjADOTNhXFcnw= Content-Disposition: inline In-Reply-To: <3b237853-dd8c-99b7-e258-7c51e9970560-1Olz3AKvcsuAKZTfuerNgRvVK+yQ3ZXh@public.gmane.org> List-ID: To: John Paul Adrian Glaubitz Cc: David Gibson , devicetree-compiler-u79uwXL29TY76Z2rM5mHXA@public.gmane.org --9OC2iooDHtHJ1Xen Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Dec 11, 2020 at 03:14:26PM +0100, John Paul Adrian Glaubitz wrote: > Hi! >=20 > On 12/11/20 2:07 AM, David Gibson wrote: > > Right, alignment issues have been a perennial problem. We find some > > platform that has alignment constraints that break, fix that, then > > someone finds the alignment fixups cause horrible performance > > problems, repeat ad nauseum. >=20 > From my discussions with GCC developers I have learnt that it shouldn't > be a problem to use memcpy() in such cases to avoid aliasing problems > resulting in unaligned access. >=20 > GCC will just optimize memcpy() in cases where an unaligned access is > faster. >=20 > > There's been another round of this pretty recently, which is probably > > the cause of the fixup. I just hope the re-optimizations that Tom > > Rini has in his pipeline don't break things again for you. >=20 > The GCC compile farm has two fast SPARC servers [1] running Debian unstab= le, > so I suggest testing such changes there before merging them. It's just restoring the historical behavior, and Rob was just saying this was a change in dtc and not libfdt, so should be fine. I sent out v3 last night, but I don't see it in the archives yet, if I sent it to you directly would you be able to give it a quick spin? Thanks! --=20 Tom --9OC2iooDHtHJ1Xen Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQGzBAABCgAdFiEEGjx/cOCPqxcHgJu/FHw5/5Y0tywFAl/ThSsACgkQFHw5/5Y0 tyyUVwwAoFz7c6yo0qfT+52vYVud9GeoS/ytrCnVXAzalCi5pJGhanTtQX9+ooYl RF8dLrjciOhdOFv84BvsTKcHk1Srgs4RcJ/11wTT4YnWYPLc6qFmGkDKhyZ9dm23 mehXuK5oqZONQJ2efPWyv541lXXvBYJa7zBpOrSpGRvxhuI59vX2jFnwcDEOWwsG 43E7XBTrRyBmwsAg8OyhJ67IVHNUNUqr82d9RRhTuIJszKDDzR4L2Shjm/UC7Vk5 NrvT6WaRJjM9fDoahi+JwFoGy4i7Kp5Hh/NbbDx6o8J7r8tdYTBYt3HDD2sYQmlA 2QxOyge+4l3ejwnF9hS0G/IfC2g3J3FkIIAw2hRIHn3vfYhM+tviNNTnt6nN33lt HZy8YHzklFB0h70+hrpfWu12f4RIRv9KP/d1bs16FHNQ8gOHZ4CWYnK2h2kQ6m4i wLT5/9WCan3OIkdsuT27i9U785LMT5x7qzRJK0D2nupf5UgCulLWoVPsy33rjeph m4x8L/uC =2nAk -----END PGP SIGNATURE----- --9OC2iooDHtHJ1Xen--