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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 9E140C76186 for ; Mon, 29 Jul 2019 20:48:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 702D32070B for ; Mon, 29 Jul 2019 20:48:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bqYg2vf6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387988AbfG2UsA (ORCPT ); Mon, 29 Jul 2019 16:48:00 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:40403 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387816AbfG2UsA (ORCPT ); Mon, 29 Jul 2019 16:48:00 -0400 Received: by mail-wr1-f67.google.com with SMTP id r1so63304125wrl.7 for ; Mon, 29 Jul 2019 13:47:58 -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:in-reply-to:user-agent; bh=RDzvvOLuO0FrlKWxE2OmL3qzW6ImORMj+8bQNrB211w=; b=bqYg2vf6S77RfIIDwmBpPvt98JMouraDjU/7gkOw4RUdkILM9kHRrxPCO1GPEiAfrB 8k7HgMX7cALTWMIvmrVFh6Z7j8UypTjrSThLnoXQzgJQEUXYLwVrpd/FYWZ3uJol2rHH Kl+IJS7l+LdQCn41iD/kRCqtErAV//frDl3lYXeMfyWBR94TF9FzeDw0owWo+OEEHPSG 8uwvF5QvbEjNHE17mrI6MRB4xoeMNHwwsqAISapLtlap5lQkdueROuTAewOxp+Z9mS11 6fPixvDgOIu7s/zq1LWwASsumNqNj8nmbp+waUiGMVX33yO5DWFgPQnkrzaBnVoeHVTY E4VQ== 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:in-reply-to:user-agent; bh=RDzvvOLuO0FrlKWxE2OmL3qzW6ImORMj+8bQNrB211w=; b=SrOym6XetfqUS9Mygsf5BZE597IYprN+KIUKN0E+MCzdt7v4DAf95nVeyzuO+4T1BX JSLmCrGLav6yps5ERjm8IbfNz2xYTy+4PcTfZJDv5Qktwl8ouK8c7Q41MCTHgaa0u09Q S4VigcIMsfwEhAMCSc0XZBkJg8ypfgm4/voqYebI1F+xK8ZbTThyiBGq3O9eLU8HBcM6 W4KtKGWLd0m461GsRqgoBy+mAn+SveLRd3Tkwkk6tgD8/tpJTq2D5sjRFh1LjEdEmbWz Gu7pDGmO8OU5Kr0QN0cRdEfOAbBkw5R9gqKNOPIKEOR91teJ32Q+Zfp8wFYj1rI1r3O5 txcA== X-Gm-Message-State: APjAAAVROinU6BxmxTaLRuM9YmXztWU7cK41/0LmS7VkOWKgprJcqlwH ObUe9/m5ToB6A6/0gYKBteI= X-Google-Smtp-Source: APXvYqz0cYI4K316CGTDakDGyEqSptDOdhcM8y/dijSRlDVX+fk7T3qYCFFRPauHBHOlOJ6IkHwRUg== X-Received: by 2002:a5d:6a52:: with SMTP id t18mr20910659wrw.178.1564433277503; Mon, 29 Jul 2019 13:47:57 -0700 (PDT) Received: from archlinux-threadripper ([2a01:4f8:222:2f1b::2]) by smtp.gmail.com with ESMTPSA id s188sm51874539wmf.40.2019.07.29.13.47.56 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 29 Jul 2019 13:47:57 -0700 (PDT) Date: Mon, 29 Jul 2019 13:47:55 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Michael Ellerman , Christophe Leroy , Segher Boessenkool , Arnd Bergmann , kbuild test robot , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, LKML , clang-built-linux Subject: Re: [PATCH] powerpc: workaround clang codegen bug in dcbz Message-ID: <20190729204755.GA118622@archlinux-threadripper> References: <20190729202542.205309-1-ndesaulniers@google.com> <20190729203246.GA117371@archlinux-threadripper> 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) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 29, 2019 at 01:45:35PM -0700, Nick Desaulniers wrote: > On Mon, Jul 29, 2019 at 1:32 PM Nathan Chancellor > wrote: > > > > On Mon, Jul 29, 2019 at 01:25:41PM -0700, Nick Desaulniers wrote: > > > But I'm not sure how the inlined code generated would be affected. > > > > For the record: > > > > https://godbolt.org/z/z57VU7 > > > > This seems consistent with what Michael found so I don't think a revert > > is entirely unreasonable. > > Thanks for debugging/reporting/testing and the Godbolt link which > clearly shows that the codegen for out of line versions is no > different. The case I can't comment on is what happens when those > `static inline` functions get inlined (maybe the original patch > improves those cases?). > -- > Thanks, > ~Nick Desaulniers I'll try to build with various versions of GCC and compare the disassembly of the one problematic location that I found and see what it looks like. 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charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnd Bergmann , LKML , clang-built-linux , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, kbuild test robot Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Jul 29, 2019 at 01:45:35PM -0700, Nick Desaulniers wrote: > On Mon, Jul 29, 2019 at 1:32 PM Nathan Chancellor > wrote: > > > > On Mon, Jul 29, 2019 at 01:25:41PM -0700, Nick Desaulniers wrote: > > > But I'm not sure how the inlined code generated would be affected. > > > > For the record: > > > > https://godbolt.org/z/z57VU7 > > > > This seems consistent with what Michael found so I don't think a revert > > is entirely unreasonable. > > Thanks for debugging/reporting/testing and the Godbolt link which > clearly shows that the codegen for out of line versions is no > different. The case I can't comment on is what happens when those > `static inline` functions get inlined (maybe the original patch > improves those cases?). > -- > Thanks, > ~Nick Desaulniers I'll try to build with various versions of GCC and compare the disassembly of the one problematic location that I found and see what it looks like. Cheers, Nathan