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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 A042CC3A5A2 for ; Tue, 3 Sep 2019 08:24:28 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6CDEC2053B for ; Tue, 3 Sep 2019 08:24:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="xTBddTOD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6CDEC2053B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:42768 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i5471-00078u-Hy for qemu-devel@archiver.kernel.org; Tue, 03 Sep 2019 04:24:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49720) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i546A-0006b7-8a for qemu-devel@nongnu.org; Tue, 03 Sep 2019 04:23:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i5469-0007pT-7L for qemu-devel@nongnu.org; Tue, 03 Sep 2019 04:23:34 -0400 Received: from mail-ot1-x344.google.com ([2607:f8b0:4864:20::344]:38226) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1i5469-0007p0-0a for qemu-devel@nongnu.org; Tue, 03 Sep 2019 04:23:33 -0400 Received: by mail-ot1-x344.google.com with SMTP id r20so15890084ota.5 for ; Tue, 03 Sep 2019 01:23:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Pi/PZdCdGJ+rlQ9IDqkNpKakJT+tNtOHVf3SZ43tHQU=; b=xTBddTODmCAvn1d1CsVgwM/HUlXd2LTcWzfFwMF4bMYb0CAhN1RjAPy9teIWTWyFyi masWI8b+SKQ4sHr8q584E8Re4cHtqsQtBd+weh9t/eiAZ653jqasLrjXxd49lnERjmWG GD4SLTuN25L2gcW7Kny2iKIVdRK2YR2oKgn+Nk5QxqaD8juW00xEPTSUr+fiqY34mzbT T0+ymrqrW3d+M3p4eeyckEccHHmW3P4rO6oWKSZLK8c7G7/eJbXJBBP66RkPdPpac/Xe C2ktVm9BVDGKqnXw5U+fOXu2QHKDeNqOuB2/FOlZx32aAMPZjtfJjADfRV3GPpvBvavD zFhw== 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=Pi/PZdCdGJ+rlQ9IDqkNpKakJT+tNtOHVf3SZ43tHQU=; b=Qu0W6BkLsU2dec8ugiG7B2ohf13i9IG7T0oA8JYhelQ3Y7Cj5RWz1zTuM3zPmwvdh5 iH5i9mtYQ4ae3eK8VBLA3JdZCSU6hNnKfqqbXh+81yoDSEBLUMGMKxiWy7T0BeC1m3yg T0Wc2TRXqqbV48W5VIj0zKUOuHkzZzy6f2Z9X/OT8XmQNiaO7xdWJMwZACnw4/WA3hTC AvZ+SJXHoQKFrqfPsE7vM3fyM6t14qKaO1ZhPfjyLaSEJLozni0+UUhSmeITtpH0LAqm SVbubzV29YHryHEq6ty9waamEdkcPHiVBp0pKKk7lpKxOT7ndYBsOVyebD0dUmfkTPGS 5JSw== X-Gm-Message-State: APjAAAUMuePkxWIb/WW84VQJ5mglIn/SZmdrXjlgdmMF0S5KQOccxxIA uONhg2tr0EDBf4llT+F3KKBcjK/aV5ytDrVNunCYJA== X-Google-Smtp-Source: APXvYqzzL3uRhF2R5f+dZdbeZ4ZkdR6tEcpTWtHk7dPrIzII3TJ2Tbb1DCMb0sVLNN/tciicMIb//5DQeKapIAZN5Rs= X-Received: by 2002:a05:6830:1015:: with SMTP id a21mr28050474otp.232.1567499012188; Tue, 03 Sep 2019 01:23:32 -0700 (PDT) MIME-Version: 1.0 References: <20190819213755.26175-1-richard.henderson@linaro.org> <20190819213755.26175-67-richard.henderson@linaro.org> <7f4eac6e-486a-3d99-b533-5fd4ac41864d@linaro.org> In-Reply-To: <7f4eac6e-486a-3d99-b533-5fd4ac41864d@linaro.org> From: Peter Maydell Date: Tue, 3 Sep 2019 09:23:21 +0100 Message-ID: To: Richard Henderson Content-Type: text/plain; charset="UTF-8" X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:4864:20::344 Subject: Re: [Qemu-devel] [PATCH v2 66/68] target/arm: Convert T16, long branches X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-arm , QEMU Developers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 28 Aug 2019 at 01:07, Richard Henderson wrote: > > On 8/27/19 2:34 AM, Peter Maydell wrote: > >> + tcg_gen_andi_i32(tmp, tmp, -4); > > > > Minor nit, but can we use 0xfffffffc like the old code did, > > to avoid the reader having to do 2s-complement arithmetic > > in their head to figure out that we're clearing the low 2 bits? > > I always preferred "x & -c" for exactly the same reason: > to avoid the reader having to do 2s compliment arithmetic > in their head to figure out that we're aligning to c. I guess this is mostly a personal thing -- I don't have in my head any idea of what doing a logical operation on a negative number does, so I always have to convert it back to "what are the actual bits here" before I understand it. thanks -- PMM