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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 8FE10C433DF for ; Thu, 28 May 2020 13:38:26 +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 56C52206F1 for ; Thu, 28 May 2020 13:38:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MFZgpZ1U" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 56C52206F1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:42574 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jeIjp-0000uO-JA for qemu-devel@archiver.kernel.org; Thu, 28 May 2020 09:38:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43516) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jeIjF-000096-C4 for qemu-devel@nongnu.org; Thu, 28 May 2020 09:37:49 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:32978 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jeIjD-0005V3-Ro for qemu-devel@nongnu.org; Thu, 28 May 2020 09:37:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590673065; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IkaZOOBjKKshBBjSRRMWXw/48nYmDJhhZzdR2EL7beY=; b=MFZgpZ1UhSmrdO8ucAvTrordBINVg31tvPc9jmxl9pFs40awLBthaIxrWkycDmwbQEGEnm 8olSeSNMwVQPIHd8NgIpHyo7Gbq/rezYZwQLyh5eZR8dKFtTvXEolHgNn9ALs6jZ8NhNnl 1JtXpyIPa4rPVIBYSG+NmtqZVGHq/x4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-157-hodvGw2HPMC8lfATVHRbKw-1; Thu, 28 May 2020 09:37:37 -0400 X-MC-Unique: hodvGw2HPMC8lfATVHRbKw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 06C8D1054F98; Thu, 28 May 2020 13:37:36 +0000 (UTC) Received: from [10.3.112.88] (ovpn-112-88.phx2.redhat.com [10.3.112.88]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E2C8360F88; Thu, 28 May 2020 13:37:34 +0000 (UTC) Subject: Re: [PATCH v2] fpu/softfloat: Silent 'bitwise negation of a boolean expression' warning To: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Thomas Huth , qemu-devel@nongnu.org References: <20200528084833.9531-1-philmd@redhat.com> <288fd554-67e2-bfd9-4b51-ac03e565161f@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <1809e3cf-5750-e21e-88bf-d27f9d1fb3c3@redhat.com> Date: Thu, 28 May 2020 08:37:34 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=eblake@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/28 03:11:04 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action 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: Richard Henderson , =?UTF-8?Q?Alex_Benn=c3=a9e?= , Aurelien Jarno , Peter Maydell Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 5/28/20 4:00 AM, Philippe Mathieu-Daudé wrote: > On 5/28/20 10:57 AM, Thomas Huth wrote: >> On 28/05/2020 10.48, Philippe Mathieu-Daudé wrote: >>> When building with clang version 10.0.0-4ubuntu1, we get: In the subject, I'd suggest s/Silent/Silence/ >>> >>> CC lm32-softmmu/fpu/softfloat.o >>> fpu/softfloat.c:3365:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation] >>> absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven ); >>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> >>> fpu/softfloat.c:3423:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation] >>> absZ0 &= ~ ( ( (uint64_t) ( absZ1<<1 ) == 0 ) & roundNearestEven ); >>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> Also, do you need to list all errors, or will just one or two representative errors be sufficient? >>> >>> Fix by rewriting the fishy bitwise AND of two bools as an int. >>> >>> Suggested-by: Eric Blake >>> Buglink: https://bugs.launchpad.net/bugs/1881004 >>> Signed-off-by: Philippe Mathieu-Daudé >>> --- >>> +++ b/fpu/softfloat.c >>> @@ -3362,7 +3362,9 @@ static int32_t roundAndPackInt32(bool zSign, uint64_t absZ, >>> } >>> roundBits = absZ & 0x7F; >>> absZ = ( absZ + roundIncrement )>>7; >>> - absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven ); >>> + if (((roundBits ^ 0x40) == 0) && roundNearestEven) { >>> + absZ &= ~1; >>> + } >> >> You could get rid of some more parentheses now: >> >> if ((roundBits ^ 0x40) == 0 && roundNearestEven) >> >> ... also in the other hunks. > > I first wrote > > if (!(roundBits ^ 0x40) && roundNearestEven) > > But then thought this would diverge from Eric suggestion, so I kept what > he wrote (which is a bit closer to the style of rest of this file). I don't mind the patch as-is for minimizing churn and matching existing style, but I also would not be opposed if you wanted to elide unnecessary (). > >> >> Anyway: >> Reviewed-by: Thomas Huth >> > > Thanks! > Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org