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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 04CFBC12002 for ; Wed, 21 Jul 2021 18:56:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1A8561221 for ; Wed, 21 Jul 2021 18:56:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232008AbhGUSPg (ORCPT ); Wed, 21 Jul 2021 14:15:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231787AbhGUSPe (ORCPT ); Wed, 21 Jul 2021 14:15:34 -0400 Received: from mail-lf1-x131.google.com (mail-lf1-x131.google.com [IPv6:2a00:1450:4864:20::131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7BB62C061757 for ; Wed, 21 Jul 2021 11:56:09 -0700 (PDT) Received: by mail-lf1-x131.google.com with SMTP id f30so4663929lfv.10 for ; Wed, 21 Jul 2021 11:56:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=aJkW/Rt80/ziMvbn4832hKqXFcNOrBwlbkHciUUuUEQ=; b=h3o4hzJQWX+TGJxM1Jtx5rcowiFdFpFGP1bJrbF2mhXZ6Iahjbd/JUD501V9ekEXeH AKH+TPFtDIlarocczD/aWA1pu8wLGBLaRHpy4i/siBaSki9h5jCAgNQpFt/qJnD1htBB mATXWGOEBa84HmjBZUdJpk8shmsNjxHoAmmV8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=aJkW/Rt80/ziMvbn4832hKqXFcNOrBwlbkHciUUuUEQ=; b=DtAZrtQATGBHDoFWEKp5GUUSCZfKtX3BUbZUIUZZ8myiLiDHPosaUx1dPSL77ZkegN whs5EtEaeqFQ8Tp4q5zIDn4pC4M9hfNRJqzLV//lrQGjqGcPeeTXPSrrJeAHJohvWCHa TV1vADaF/6sRGXct49gjDq2pgJOHOwJ06ttxUgOY0Is9KcYtw5cVe9EMvR7zmBW19+My 0T0AeXaR15j2vJSMDrKM4nzDZW6nqLEwMU1tA1zIrYhoQaA/aAJny4j6RAwo5k+C2Kii B4TxCIMi2DKySKLiq9UUW0mljrn9I3PiEQsc/TOk8cU17sI4Avk7NVsQKMbrsEselcF3 Ytyw== X-Gm-Message-State: AOAM530hGA6zsrfrqkJpNpVwhOLnO3VAA0wSv++bTub8EAtor+7m/Gle 6gLkzn1972ZV81FlGLX9rcU9u5CiyitD8xrI X-Google-Smtp-Source: ABdhPJyOZJ7qEpYoUPgBAuObSTWXt3uTzLiBsXrCN/gCmpS3ej8V59hsAuuUCdeluQYvcGOMUjapPQ== X-Received: by 2002:a19:771c:: with SMTP id s28mr25948903lfc.358.1626893767646; Wed, 21 Jul 2021 11:56:07 -0700 (PDT) Received: from mail-lf1-f42.google.com (mail-lf1-f42.google.com. [209.85.167.42]) by smtp.gmail.com with ESMTPSA id c5sm2892977ljj.17.2021.07.21.11.56.06 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 Jul 2021 11:56:07 -0700 (PDT) Received: by mail-lf1-f42.google.com with SMTP id u13so4653038lfs.11 for ; Wed, 21 Jul 2021 11:56:06 -0700 (PDT) X-Received: by 2002:a05:6512:404:: with SMTP id u4mr25898153lfk.40.1626893766677; Wed, 21 Jul 2021 11:56:06 -0700 (PDT) MIME-Version: 1.0 References: <20210721135926.602840-1-nborisov@suse.com> In-Reply-To: From: Linus Torvalds Date: Wed, 21 Jul 2021 11:55:50 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] lib/string: Bring optimized memcmp from glibc To: Nikolay Borisov Cc: Linux Kernel Mailing List , Nick Desaulniers , linux-fsdevel , Dave Chinner Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 21, 2021 at 11:45 AM Linus Torvalds wrote: > > - the code generation is actually quite good with both gcc and clang. Side note: I only looked at whether the code looked good, I didn't check whether it looked *correct*. So caveat emptor. It looks trivially correct both on the source and assembly level, but it's entirely untested, which probably means that it has some stupid bug. Linus