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=-3.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 A78A9C388F7 for ; Tue, 10 Nov 2020 22:15:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 702EA20637 for ; Tue, 10 Nov 2020 22:15:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="K/LL2lfA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732240AbgKJWPP (ORCPT ); Tue, 10 Nov 2020 17:15:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731805AbgKJWPP (ORCPT ); Tue, 10 Nov 2020 17:15:15 -0500 Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 049DDC0613D1 for ; Tue, 10 Nov 2020 14:15:15 -0800 (PST) Received: by mail-qk1-x741.google.com with SMTP id y197so13176044qkb.7 for ; Tue, 10 Nov 2020 14:15:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=uIOzI8x2X1SZGvfM2NfEeGZjOdYhmoI7amgUKQgpunY=; b=K/LL2lfALMmOHYaFluLeF7ajWtNG/IZxN6cpjSQUl3oKYuF63EVb6hnPmRksiKpikc zDvm4gP8LZe6+aH1RbfsNB6+sxlL+B0R+KvW5rfZKSYa98ZYNCzi0sbUfyQAWvSrMu2t Q9H9n35b1vXgQvF1teMaaJLsdL1hOytCQujaFVLB+jZGuBaKBipBV9OtcFmzp6reMSHv U/le7QaCI6uxNFLwbK4l2INR/SQriinbei2NJXAyNLba8+eiI/zIzU5MFUfGonx1QLyL hkS6uhZxrnn3xzXvuYIdCMwqyj4vYDeg/ozt+G+2MKMR8lNcwYD6fVo7ZxUxwTN0Vo+1 1ujw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:date:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=uIOzI8x2X1SZGvfM2NfEeGZjOdYhmoI7amgUKQgpunY=; b=I1h7WESmj1koaBtReLkbItuBmDGd60/XeWExJ6lenOt6+LtA198zVVvOmPzmuGHJby EjM1e7Ztn0cyQuEKEKS7qsZjfOAbCDr6E4XoZAq46bVLXh+dZ6wl0k7BICPUB9y8FakH eAfi2zDu5uPzjE0++RpPJHqO0AO/SQRQNJ8ECleCkoaED28Wk1jt9L3cfeElocKqclrC 58YnH9zzXqqIaz9FfRg573ybpI/y7ooTkEwWKUW7XLRfIXmAo6mZRJGfYK8ciorAH+1d tfuLmWJJyRDvXBGW50/NJxV99HTf0LT2aD46Z0Bx5wbg7AImHDQK8ftndUw2/9K0Oglv ogqA== X-Gm-Message-State: AOAM530MRFyPeHCfzNV1mgXYwx+kW8g7OJH9AwGPk0kcBPRgv7bJ0sC/ uFVpSxvRFdT/pu/87PgwM4I= X-Google-Smtp-Source: ABdhPJxJVjhLD6VaxM0tXb7NyppHqncBfJwFgOko/fVzM69cKPtOKyHEp8DOvei2rH9hArmCIjlM5g== X-Received: by 2002:a37:7ac3:: with SMTP id v186mr21828124qkc.451.1605046514064; Tue, 10 Nov 2020 14:15:14 -0800 (PST) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id c76sm189612qkb.20.2020.11.10.14.15.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Nov 2020 14:15:13 -0800 (PST) Sender: Arvind Sankar From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Tue, 10 Nov 2020 17:15:11 -0500 To: Nick Desaulniers Cc: Adrian Ratiu , Nathan Chancellor , Arnd Bergmann , Linux ARM , clang-built-linux , Russell King , LKML , Collabora Kernel ML , Ard Biesheuvel Subject: Re: [PATCH 2/2] arm: lib: xor-neon: disable clang vectorization Message-ID: <20201110221511.GA1373528@rani.riverdale.lan> References: <20201106051436.2384842-1-adrian.ratiu@collabora.com> <20201106051436.2384842-3-adrian.ratiu@collabora.com> <20201106101419.GB3811063@ubuntu-m3-large-x86> <87wnyyvh56.fsf@collabora.com> <871rh2i9xg.fsf@iwork.i-did-not-set--mail-host-address--so-tickle-me> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 10, 2020 at 01:41:17PM -0800, Nick Desaulniers wrote: > On Mon, Nov 9, 2020 at 11:51 AM Adrian Ratiu wrote: > > > > On Fri, 06 Nov 2020, Nick Desaulniers > > wrote: > > > +#pragma clang loop vectorize(enable) > > > do { > > > p1[0] ^= p2[0] ^ p3[0] ^ p4[0] ^ p5[0]; p1[1] ^= > > > p2[1] ^ p3[1] ^ p4[1] ^ p5[1]; > > > ``` seems to generate the vectorized code. > > > > > > Why don't we find a way to make those pragma's more toolchain > > > portable, rather than open coding them like I have above rather > > > than this series? > > > > Hi again Nick, > > > > How did you verify the above pragmas generate correct vectorized > > code? Have you tested this specific use case? > > I read the disassembly before and after my suggested use of pragmas; > look for vld/vstr. You can also add -Rpass-missed=loop-vectorize to > CFLAGS_xor-neon.o in arch/arm/lib/Makefile and rebuild > arch/arm/lib/xor-neon.o with CONFIG_BTRFS enabled. > https://godbolt.org/z/1oo9M6 With the __restrict__ keywords added, clang seems to vectorize the loop, but still reports that vectorization wasn't beneficial -- any idea what's going on?