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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 0397BC004E4 for ; Wed, 13 Jun 2018 03:58:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 592C720693 for ; Wed, 13 Jun 2018 03:58:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 592C720693 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933998AbeFMD61 convert rfc822-to-8bit (ORCPT ); Tue, 12 Jun 2018 23:58:27 -0400 Received: from ozlabs.org ([203.11.71.1]:35803 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933696AbeFMD60 (ORCPT ); Tue, 12 Jun 2018 23:58:26 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPSA id 415Cf84zfqz9s2g; Wed, 13 Jun 2018 13:58:24 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au From: Michael Ellerman To: Christophe LEROY , Segher Boessenkool Cc: Benjamin Herrenschmidt , Paul Mackerras , wei.guo.simon@gmail.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v6 3/4] powerpc/lib: implement strlen() in assembly In-Reply-To: References: <85de16f5629ac9f4a815230cced361908758b53a.1528791416.git.christophe.leroy@c-s.fr> <8b89f2e21f7e3a865105eeeeda509243db393454.1528791416.git.christophe.leroy@c-s.fr> <20180612145315.GJ27520@gate.crashing.org> Date: Wed, 13 Jun 2018 13:58:24 +1000 Message-ID: <877en3tk0v.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christophe LEROY writes: > Le 12/06/2018 à 16:53, Segher Boessenkool a écrit : >> On Tue, Jun 12, 2018 at 09:14:53AM +0000, Christophe Leroy wrote: >>> --- >>> Not tested on PPC64. >> >> It won't be acceptable until that happens. It also is likely quite bad >> performance on all 64-bit CPUs from the last fifteen years or so. Or you >> did nothing to prove otherwise, at least. > > Will it be as bad as the generic implementation which does it byte per > byte ? > > I don't have any 64 bits target, can someone test it using the test app > I have added in selftests ? I /can/ but I won't have time this week. > Or should I just leave it as is for 64 bits and just do the > implementation for 32 bits until someone wants to try and do it for PPC64 ? That's probably best yeah. cheers