Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752621AbbHUIBt (ORCPT ); Fri, 21 Aug 2015 04:01:49 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:38735 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751597AbbHUIBr (ORCPT ); Fri, 21 Aug 2015 04:01:47 -0400 Message-ID: <55D6DAE5.20304@ti.com> Date: Fri, 21 Aug 2015 11:01:41 +0300 From: Tomi Valkeinen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: yalin wang CC: , , , open list Subject: Re: [RFC] fbdev/riva:change to use generice function to implement reverse_order() References: <55D5B3A9.6040901@ti.com> <867D66CD-9A3B-4536-B537-8C065C85E497@gmail.com> <55D6C812.6080400@ti.com> <4DCC50F3-9B6D-4A3A-9693-E7A7196564A8@gmail.com> In-Reply-To: <4DCC50F3-9B6D-4A3A-9693-E7A7196564A8@gmail.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="PBjJ09ID8wXspKNAgmniaObit7tISXhnK" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2142 Lines: 62 --PBjJ09ID8wXspKNAgmniaObit7tISXhnK Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 21/08/15 10:46, yalin wang wrote: >>> i investigate on arm64 platforms: >> >> Ok. So is any arm64 platform actually using these devices? If these >> devices are mostly used by 32bit x86 platforms, optimizing them for >> arm64 doesn't make any sense. >> >> Possibly the patches are still good for x86 also, but that needs to be= >> proven. >> > not exactly, because x86_64 don=92t have hardware instruction to do rbi= t OP, > i compile by test : For old drivers i386 may be more relevant than x86_64. So you don't have the actual HW? These kind of optimizations should have some real world measurements, not just compiling, looking at the assembly and guessing whether it's faster or not. Tomi --PBjJ09ID8wXspKNAgmniaObit7tISXhnK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJV1trlAAoJEPo9qoy8lh71cDIP+wbZJDah/jhN9ZGMjDFzhrqe zYmS++S7+l8mFPEuSWYuhRmyI+6NZ3tNQpXz/xoH8ZsEsTaxhzZtT0KTLmYDa/m+ XbtnUmm8VrB7IcMSJtqYQbnWzU+0ra+YOHFRJQzFKVkf20d2NnlE+UPvNCUkkjtQ v743XUgA4bxusfcsnES36PC3LPGyCt94hH1Rs0QXwxJVyeq+bqdJ2XnCWHa9RJPV YZ8DCi7bO1WiBcu8lALo+LBhnKaG0o2mTR59/zwzRsrinw62o7BTXGGOkZh179aa awKZUnMW6JRH3P8d23148Lht3QNBM1xvRIy7tMNszk7ApjzXz/+egkj6y/mlYJ7K HMlPYHB9yOaIuiESSxYiGkQO4qyRQUEf5RmgyLkOzZOHARzPcUgNijgqhkCC1S6u dZVWiwYnpDvFqvEX52jxyrGsn5JvkIWgk9Uln/UInnOtglP/p2yA5PwMJWzjRhjL pdu2yHR1EcrnqpmHxo6I55mWchvs0e+X0Lk0eMPN8vctN+EmjeUbmiN9U/ec3e6h bfpj/sq5HZ3pDfzksx+U0ShARmXegZca89eajhdHuEComjO3I9L8CO1wOlRHkEA7 4j1NWjoAQ9jVIAMGh3hH4g6rzlUytMgBjTioVVcERl7CYrELouKag3/OWerdvvoJ FdiSETaeqoooB7nZbrHw =sB5t -----END PGP SIGNATURE----- --PBjJ09ID8wXspKNAgmniaObit7tISXhnK-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/