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=-2.4 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_MUTT 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 EA79FC04AB6 for ; Fri, 31 May 2019 20:26:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDC9B26EEB for ; Fri, 31 May 2019 20:26:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Xv43EpmE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727538AbfEaU0L (ORCPT ); Fri, 31 May 2019 16:26:11 -0400 Received: from mail-ed1-f66.google.com ([209.85.208.66]:42372 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727354AbfEaU0K (ORCPT ); Fri, 31 May 2019 16:26:10 -0400 Received: by mail-ed1-f66.google.com with SMTP id g24so6692552eds.9 for ; Fri, 31 May 2019 13:26:09 -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=Gkdrhj+L2y9Un3DqIxCBN2IczH3NAgr/P0YLMvWGg3k=; b=Xv43EpmEIYCOnqrcH6IC1jp47hvR8jTZmpsuMilbWt6IoPWH1ceBQLdNcwW1Ar1Tfc BaL/lNspAs5IRQaUY2ITsepMDgaj4bX36mXu8JbEV2gn5MfxqziePZ1goCdh5rxF2xRA ephcT0SA8NIjA9rlqzcqsDfFXVSRJ4VndZuCK5rnmo2R7Pa8KPARwxESCUxVSjFOQ1bw nn6Bxa61HWZ7m7UPLW9L54TSAB8QXfwRo79eIgjevEGPWCKOOxgF3+WGb9v93fCtZ3wH 8Y6Ye6iZTLO/yFY9AUWH/B6+RJj7c9Q/h8j3uw1AQaxu4kNzFkHkNhvxFovkT2M13MWh GCLw== 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=Gkdrhj+L2y9Un3DqIxCBN2IczH3NAgr/P0YLMvWGg3k=; b=tXJ1GZhzw5BiIgC13sg92xyCgSabkdg+JS5m5wVc1rQO+G2RSye4lA8I2qGCGU1j6J v1FZXgpBJ7fjf3HFIgP9wEKn7OoukosIIzL4rtgkW7JPjxkbrncnW1mHLNENAR7rW20c Ay+mNWnBzt1RKTnagBWzzBLudbwDsh4074gOZvH0wuqzpTmdf1fVyr5sEGHxPhNb55wR dNlgWudp1lGV/cS8B7SlPrQLHo8IV+m+kgit2694dRNsiZkjtXuE63pvrXpmojoLyFzq wGK7gGOv+0LxvU5ugm0zgk4RhFtMhysnxVkQ2ZoOWvTtNebMiotH3lZkDgbZDzaOhcX5 95ow== X-Gm-Message-State: APjAAAVzcHQrvYKI6yuUobnji9kUna1Lin3nh6compUUmwfPkJN1ey+e qkAbQIg94Y/jwenv2/Btx/w= X-Google-Smtp-Source: APXvYqxixZFEj5U32gsuL97OYf945hk0gTpmJ868WJqXPlesOklKj4GB4h8NEuJIo6Ibi7k6Kx9AYA== X-Received: by 2002:a17:906:a94c:: with SMTP id hh12mr11415070ejb.143.1559334368623; Fri, 31 May 2019 13:26:08 -0700 (PDT) Received: from archlinux-epyc ([2a01:4f9:2b:2b15::2]) by smtp.gmail.com with ESMTPSA id i45sm1892124eda.67.2019.05.31.13.26.07 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 31 May 2019 13:26:07 -0700 (PDT) Date: Fri, 31 May 2019 13:26:05 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Arnd Bergmann , Russell King , Nicolas Pitre , Stefan Agner , Linux ARM , Linux Kernel Mailing List , Ard Biesheuvel , clang-built-linux Subject: Re: [PATCH] ARM: xor-neon: Replace __GNUC__ checks with CONFIG_CC_IS_GCC Message-ID: <20190531202605.GA78113@archlinux-epyc> References: <20190528235742.105510-1-natechancellor@gmail.com> <20190531183227.GA34102@archlinux-epyc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 31, 2019 at 01:06:13PM -0700, Nick Desaulniers wrote: > On Fri, May 31, 2019 at 12:21 PM Arnd Bergmann wrote: > > clang, I would suggest dropping your patch then, and instead adding > > I disagree. The minimum version of gcc required to build the kernel > is 4.6, so the comment about older versions of gcc is irrelevant and > should be removed. > > Nathan's -Rpass warnings are warning that vectorization was not > calculated to be profitable **for 1 of the 4 functions** by LLVM. > Surely we wouldn't disable NEON opts for XOR because 1 of 4 was not > vectorized? Well I kept it short but clang warns that all of the loops are not profitable. However, the config option for xor-neon.c is CONFIG_XOR_BLOCKS, which also controls the arm64 implementation. We wouldn't want to disable it for clang altogether if it works on arm64 fine. If it turns out to be broken for both, I suppose I would be okay with disabling CONFIG_XOR_BLOCKS for clang but it should be done in a separate patch as this one should be applied regardless of clang working or not (because this warning will appear again when clang is fixed). Cheers, Nathan