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=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, 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 67BCBC433B4 for ; Wed, 7 Apr 2021 08:33:20 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 1BFB9611EE for ; Wed, 7 Apr 2021 08:33:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BFB9611EE Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.106502.203662 (Exim 4.92) (envelope-from ) id 1lU3cc-0007QN-KS; Wed, 07 Apr 2021 08:33:10 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 106502.203662; Wed, 07 Apr 2021 08:33:10 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lU3cc-0007QG-HM; Wed, 07 Apr 2021 08:33:10 +0000 Received: by outflank-mailman (input) for mailman id 106502; Wed, 07 Apr 2021 08:33:09 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lU3cb-0007QB-Cp for xen-devel@lists.xenproject.org; Wed, 07 Apr 2021 08:33:09 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 4dd7cf2c-6911-46c3-bfe4-727186f81fd3; Wed, 07 Apr 2021 08:33:08 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 330F4AFCF; Wed, 7 Apr 2021 08:33:07 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 4dd7cf2c-6911-46c3-bfe4-727186f81fd3 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1617784387; h=from:from:reply-to: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=0Gr5nHKCKAIvSxhQXPgssSq0Wbe/7CEist10eX0tuEQ=; b=lAxUYMyo7e2+KVgE6rBLVg3UIRSxDvJWWHer0uszX2cX+1nTz2sLUVHJ8ZYtBii9YZh/2Q yQBOFn/X3/bTxB9UAi2HxYC/7CpWUgo9VRi6kDw55VVy7Z5lrETPkgBiHzm1J9NGMyj4TP yOc+ASnmD1XHuk4Rrgrp1gSdMD43vAE= Subject: Re: [PATCH 02/23] lib: move 64-bit div/mod compiler helpers To: Julien Grall Cc: Andrew Cooper , George Dunlap , Ian Jackson , Stefano Stabellini , Wei Liu , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , "xen-devel@lists.xenproject.org" References: <0fec827f-bb0b-4ea1-7757-9c27e9138be7@suse.com> <008a8b14-8f58-2127-9e97-87c696e07b5e@xen.org> <0ddcecbb-dc42-ba4e-fccc-6988c7e54456@suse.com> From: Jan Beulich Message-ID: <75299b2a-9610-57fb-95a3-c49d926af54b@suse.com> Date: Wed, 7 Apr 2021 10:33:07 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 06.04.2021 21:34, Julien Grall wrote: > Hi Jan, > > On 01/04/2021 16:23, Jan Beulich wrote: >> On 01.04.2021 16:56, Julien Grall wrote: >>> On 01/04/2021 11:19, Jan Beulich wrote: >>>> --- a/xen/common/lib.c >>>> +++ b/xen/lib/divmod.c >>>> @@ -40,7 +40,6 @@ >>>> * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF >>>> * SUCH DAMAGE. >>>> */ >>>> -#if BITS_PER_LONG == 32 >>> >>> In theory BITS_PER_LONG == 32 is not quite the same as 32-bit arch. Can >>> you clarify whether this code is necessary on 64-bit arch where long is >>> only 32-bit. >> >> Likely the compiler can get away without invoking these helpers, so >> the code would remain unused. I'm uncertain whether CONFIG_64BIT >> ought to be set for such an architecture, as we assume sizeof(long) >> == sizeof(void*), and hence pointers would then need to be 32-bit >> as well there. > > This is a fair point. Would you mind to add a sentence explaining that > in the commit message? I've added "Note that we imply "32-bit arch" to be the same as BITS_PER_LONG == 32, i.e. we aren't (not just here) prepared to have a 64-bit arch with BITS_PER_LONG == 32. Yet even if we supported such, likely the compiler would get away there without invoking these helpers, so the code would remain unused in practice." > With that: > > Acked-by: Julien Grall Thanks. Any chance to also get an ack on patch 1, so at least these two (or three, seeing that you also did ack patch 3) could go in before my re-posting of the series to add the one line commit message additions that you did ask for on all the str* and mem* patches? (Alternatively I could take the time and re-order the two.) Jan