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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 EB393C1B0F1 for ; Tue, 19 Jun 2018 21:55:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F68020652 for ; Tue, 19 Jun 2018 21:55:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8F68020652 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967312AbeFSVzQ (ORCPT ); Tue, 19 Jun 2018 17:55:16 -0400 Received: from smtprelay0226.hostedemail.com ([216.40.44.226]:33145 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755466AbeFSVzJ (ORCPT ); Tue, 19 Jun 2018 17:55:09 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay03.hostedemail.com (Postfix) with ESMTP id 6C589837F24C; Tue, 19 Jun 2018 21:55:08 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: quiet96_2c9ff3dede142 X-Filterd-Recvd-Size: 2447 Received: from XPS-9350.home (unknown [47.151.150.235]) (Authenticated sender: joe@perches.com) by omf05.hostedemail.com (Postfix) with ESMTPA; Tue, 19 Jun 2018 21:55:06 +0000 (UTC) Message-ID: <951ccf2a257fb8f8827f88e1c17ce64d23173e94.camel@perches.com> Subject: Re: [PATCH] kvm: x86: mmu: Add cast to negated bitmasks in update_permission_bitmask() From: Joe Perches To: Matthias Kaehlcke Cc: Paolo Bonzini , Nick Desaulniers , rkrcmar@redhat.com, Thomas Gleixner , hpa@zytor.com, x86@kernel.org, kvm@vger.kernel.org, LKML , Masahiro Yamada Date: Tue, 19 Jun 2018 14:55:05 -0700 In-Reply-To: <20180619211019.GE169030@google.com> References: <20180615182945.GN88063@google.com> <66b5e5c3ed82a5e1559419deb841c57bf0751fd3.camel@perches.com> <20180619183622.GB169030@google.com> <7547dfd4045a5acf23505887065bc228e65f2ff9.camel@perches.com> <20180619211019.GE169030@google.com> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.28.1-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-06-19 at 14:10 -0700, Matthias Kaehlcke wrote: > On Tue, Jun 19, 2018 at 12:11:27PM -0700, Joe Perches wrote: > > -Wconstant-conversion is only issued when a *constant value* is assigned to > an incompatible type. > > > Trying to allow a "make W=3" to be compiler warning message free > > is also silly. > > > > I think it's better to make the warning emitted only at a W=3 > > level instead. > > Another difference with -Wsign-conversion is that enabling it would > probably result in thousands of warnings. Do you have evidence that > there is a significant number of spurious -Wconstant-conversion > warnings? Not my issue really. You're advocating for making the code more complex/ugly for a condition where the result is identical. Do you have evidence this is the only location in an allyesconfig compilation?