From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFEEAC2D0C6 for ; Wed, 11 Dec 2019 13:56:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5324222C4 for ; Wed, 11 Dec 2019 13:56:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729690AbfLKN4T (ORCPT ); Wed, 11 Dec 2019 08:56:19 -0500 Received: from www62.your-server.de ([213.133.104.62]:38504 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727554AbfLKN4T (ORCPT ); Wed, 11 Dec 2019 08:56:19 -0500 Received: from [2001:1620:665:0:5795:5b0a:e5d5:5944] (helo=localhost) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1if2TP-0007p8-I9; Wed, 11 Dec 2019 14:56:15 +0100 Date: Wed, 11 Dec 2019 14:56:15 +0100 From: Daniel Borkmann To: Russell King Cc: Shubham Bansal , Alexei Starovoitov , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ARM: net: bpf: improve prologue code sequence Message-ID: <20191211135615.GA25011@linux.fritz.box> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.101.4/25660/Wed Dec 11 10:47:07 2019) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Dec 09, 2019 at 11:17:30AM +0000, Russell King wrote: > Improve the prologue code sequence to be able to take advantage of > 64-bit stores, changing the code from: > > push {r4, r5, r6, r7, r8, r9, fp, lr} > mov fp, sp > sub ip, sp, #80 ; 0x50 > sub sp, sp, #600 ; 0x258 > str ip, [fp, #-100] ; 0xffffff9c > mov r6, #0 > str r6, [fp, #-96] ; 0xffffffa0 > mov r4, #0 > mov r3, r4 > mov r2, r0 > str r4, [fp, #-104] ; 0xffffff98 > str r4, [fp, #-108] ; 0xffffff94 > > to the tighter: > > push {r4, r5, r6, r7, r8, r9, fp, lr} > mov fp, sp > mov r3, #0 > sub r2, sp, #80 ; 0x50 > sub sp, sp, #600 ; 0x258 > strd r2, [fp, #-100] ; 0xffffff9c > mov r2, #0 > strd r2, [fp, #-108] ; 0xffffff94 > mov r2, r0 > > resulting in a saving of three instructions. > > Signed-off-by: Russell King Applied, thanks!