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=-10.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 B675CC606B0 for ; Tue, 9 Jul 2019 06:49:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86463216FD for ; Tue, 9 Jul 2019 06:49:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Djoi1z+O" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726403AbfGIGt5 (ORCPT ); Tue, 9 Jul 2019 02:49:57 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:39204 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726055AbfGIGt4 (ORCPT ); Tue, 9 Jul 2019 02:49:56 -0400 Received: by mail-wr1-f65.google.com with SMTP id x4so19658034wrt.6 for ; Mon, 08 Jul 2019 23:49:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=Nb0pkc+k4Qz3CzHqObu3Bzh+hOHM655Cn2712+LoHC0=; b=Djoi1z+OJdSQcbc/LHWSmwd9/9O9pkUGvPL14F6N7LW+l0FNebr+OsMd06cuG1vmiq 9pmmo5vgmdUxRkJ/ClYyBf8TXiMy45EGTo8PjW1nO5ACH5Nlswhavg1yZP2f1sB/6Jt+ bLiVFFTFIwWIYSFgwBCk4pMUiUgXnPOn+YFGc2ujMYz+xBJkxJn9NuZV5Aw4R4Rdvrj4 xsHkHQ8G3CD0OJjE+Cr+HjCIKVjIUAVeUOjGWWlAF/WrAEP9Ymvqb6I3xRcGp3nhdQp9 0HQ2MXRlz4O1ffK9GMUfoJx+7rBFQJQ/e4EB2xbgCcw8VLKhe+FWoVe/B3h1EXh1PG1w TZLQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=Nb0pkc+k4Qz3CzHqObu3Bzh+hOHM655Cn2712+LoHC0=; b=TfSDVWZTgl1LjhT0UHsoyeeLfdYsWcXHbUPaMekCxixV8qRfaeoth1B4BSkdUJDd4M xISWD2ADf/Qh8KBcFst25jC3rW+mVwF2Yg1ka5X2J/QxSnngcH6pAZ7UGVBVRa+zHxE/ bZWRcArEU6Y+9f2Ozxsebbg43va5kDGVc9cbdDjqqngrepnHENfsWFjV3xNKqfPbF2xt FytUrZLGapqcuzGkEmcEOMtB0/0I5PYoUOS9tsVp6nErNwN/RpTSsXpVEOCQkh2AF4a8 8lE742WIdPIwK05jSKoJTGS++1N7WawBBAbx20AjzHDDGfO9KaU/LJ5dcF5q6yhssAWf hUww== X-Gm-Message-State: APjAAAVAVEGRLWjema5TVLpqkwwedlb6kBq1Scl9H8lEQaUxPXO+WYGN aDd8fneDUTo1byMGt88vlJk= X-Google-Smtp-Source: APXvYqxbWBP22Hj6gv+5vEr97/SBM8AtFOB6BACIXVuXsQzH0yNmZQ/xlOJZPUbpeE4pwgOrMQHNug== X-Received: by 2002:adf:dd51:: with SMTP id u17mr21977289wrm.218.1562654994345; Mon, 08 Jul 2019 23:49:54 -0700 (PDT) Received: from archlinux-threadripper ([2a01:4f8:222:2f1b::2]) by smtp.gmail.com with ESMTPSA id n3sm10904758wrt.31.2019.07.08.23.49.53 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 08 Jul 2019 23:49:53 -0700 (PDT) Date: Mon, 8 Jul 2019 23:49:52 -0700 From: Nathan Chancellor To: Christophe Leroy Cc: Michael Ellerman , Segher Boessenkool , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH v2] powerpc: slightly improve cache helpers Message-ID: <20190709064952.GA40851@archlinux-threadripper> References: <45hnfp6SlLz9sP0@ozlabs.org> <20190708191416.GA21442@archlinux-threadripper> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 09, 2019 at 07:04:43AM +0200, Christophe Leroy wrote: > > > Le 08/07/2019 à 21:14, Nathan Chancellor a écrit : > > On Mon, Jul 08, 2019 at 11:19:30AM +1000, Michael Ellerman wrote: > > > On Fri, 2019-05-10 at 09:24:48 UTC, Christophe Leroy wrote: > > > > Cache instructions (dcbz, dcbi, dcbf and dcbst) take two registers > > > > that are summed to obtain the target address. Using 'Z' constraint > > > > and '%y0' argument gives GCC the opportunity to use both registers > > > > instead of only one with the second being forced to 0. > > > > > > > > Suggested-by: Segher Boessenkool > > > > Signed-off-by: Christophe Leroy > > > > > > Applied to powerpc next, thanks. > > > > > > https://git.kernel.org/powerpc/c/6c5875843b87c3adea2beade9d1b8b3d4523900a > > > > > > cheers > > > > This patch causes a regression with clang: > > Is that a Clang bug ? No idea, it happens with clang-8 and clang-9 though (pretty sure there were fixes for PowerPC in clang-8 so something before it probably won't work but I haven't tried). > > Do you have a disassembly of the code both with and without this patch in > order to compare ? I can give you whatever disassembly you want (or I can upload the raw files if that is easier). Cheers, Nathan > > Segher, any idea ? > > Christophe > > > > > https://travis-ci.com/ClangBuiltLinux/continuous-integration/jobs/213944668 > > > > I've attached my local bisect/build log. > > > > Cheers, > > Nathan > >