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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 8320DC4363A for ; Thu, 29 Oct 2020 14:42:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1947720E65 for ; Thu, 29 Oct 2020 14:42:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=amacapital-net.20150623.gappssmtp.com header.i=@amacapital-net.20150623.gappssmtp.com header.b="PffPZFVs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727811AbgJ2Omk (ORCPT ); Thu, 29 Oct 2020 10:42:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726251AbgJ2Omg (ORCPT ); Thu, 29 Oct 2020 10:42:36 -0400 Received: from mail-wr1-x442.google.com (mail-wr1-x442.google.com [IPv6:2a00:1450:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F84CC0613D3 for ; Thu, 29 Oct 2020 07:42:08 -0700 (PDT) Received: by mail-wr1-x442.google.com with SMTP id b8so3090346wrn.0 for ; Thu, 29 Oct 2020 07:42:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amacapital-net.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=fPw6NFmb8fLcJVP5lqOvf3z1qT6u6At9MFl+1mVTcr4=; b=PffPZFVsq5+Fxw6YFoSN+arrFKwsL3ZCw8i5ZB+fCUjccFIOjKssTOMKVBje4ALAxX TjHHoI9i2Wlb1JWSZ/aIofIzf5qJ7w8n9sw4QhGhNaMmxnbzfc1fUnTGTut6T1wI3QXp zaF/tzviyATa64rHxMoRA+TpDr/OdNrc6jZpJR6Ozio5v0fG1nVzbleMNhJaO+wFuNnU Ilxjk3/qznBbOBSb/GF8UeCPzIuu9w0SBEwXzW2OTxo/5iZGog1iXl/f8ImdzslhYmds 39xEKLJOI5Iz4bphpeGeWeD+EDOw8hEHLaZuw9oxbpNpG/9NqlT2FcwulV8zlTbSbU+H PlJQ== 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=fPw6NFmb8fLcJVP5lqOvf3z1qT6u6At9MFl+1mVTcr4=; b=jwuTR2YM06D+i/Y9ECLM8ipuX2SiJ7WpBNwaT+jDLP/UUL0EHbOscn5VQIrpBI4Lru EMVfMwvu+CMhuQT6+opO8W/oNOaUnbvbtpaX2XEDlaomieGjVAf3b0zgkvtUxK+PzVq7 Jptb5IlqVUT8cbYsG3SUH/+Rc4vmSugfX9HCeN+kn5guU2a872zu52LHmUgV3ZSJZclj 44T7X3inpW6OYxJDcFW6Zd0RI4AIL20kXGskrM4sSZIOaVVsTyPDpcGcBqhEblenchBu ew+odOGLighMmUdBRY6/t8m/lCRqlCuUdqofmMJef3m5nZG9nN/IkiXYWj0+OYc06hIt hsfw== X-Gm-Message-State: AOAM532DrhP1mefX6B0Wbdamcq78UFzBBWpcLhJbH2RoOfVJxIX61W9Y EfJKC8XKrIEJBrglaRtdVZzECt3m2l4T1Trc+TQ9/Q== X-Google-Smtp-Source: ABdhPJyx8OoVeVQA4V+c9XkOJaWG9rrSEmwjo721QTz3nJlHCfOnITXG0VX1t5Z/c6d365xIhg3LwA6ZSsdzQURjL6c= X-Received: by 2002:adf:ff86:: with SMTP id j6mr6013437wrr.184.1603982526911; Thu, 29 Oct 2020 07:42:06 -0700 (PDT) MIME-Version: 1.0 References: <20201029142915.131752-1-ubizjak@gmail.com> In-Reply-To: <20201029142915.131752-1-ubizjak@gmail.com> From: Andy Lutomirski Date: Thu, 29 Oct 2020 07:41:55 -0700 Message-ID: Subject: Re: [PATCH] x86/entry/64: Use TEST %reg,%reg instead of CMP $0,%reg To: Uros Bizjak Cc: X86 ML , LKML , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 29, 2020 at 7:29 AM Uros Bizjak wrote: > > Use TEST %reg,%reg which sets the zero flag in the same way > as CMP $0,%reg, but the encoding uses one byte less. This will make a Linux distro fit on an embedded device that previously had four bytes too little flash :) Reviewed-by: Andy Lutomirski