From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <mliska@suse.cz>
Received: from mx2.suse.de (mx2.suse.de [195.135.220.15])
 by sourceware.org (Postfix) with ESMTPS id 4F9C1383E809
 for <gcc-patches@gcc.gnu.org>; Mon, 29 Jun 2020 17:24:52 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 4F9C1383E809
Authentication-Results: sourceware.org;
 dmarc=none (p=none dis=none) header.from=suse.cz
Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mliska@suse.cz
X-Virus-Scanned: by amavisd-new at test-mx.suse.de
Received: from relay2.suse.de (unknown [195.135.221.27])
 by mx2.suse.de (Postfix) with ESMTP id 251AAAAC5;
 Mon, 29 Jun 2020 17:24:51 +0000 (UTC)
Subject: Re: PSA: Default C++ dialect is now C++17
To: Marek Polacek <polacek@redhat.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
References: <20200626193409.GB3394@redhat.com>
 <d7655b2a-fb53-6862-d1a3-bd77ec7ff8d2@suse.cz>
 <20200629145741.GG3394@redhat.com>
From: =?UTF-8?Q?Martin_Li=c5=a1ka?= <mliska@suse.cz>
Message-ID: <7d52eb4c-0016-1ba7-6d2a-af987df84585@suse.cz>
Date: Mon, 29 Jun 2020 19:24:50 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.9.0
MIME-Version: 1.0
In-Reply-To: <20200629145741.GG3394@redhat.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS,
 KAM_NUMSUBJECT, KAM_SHORT, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,
 SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on
 server2.sourceware.org
X-BeenThere: gcc-patches@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-patches mailing list <gcc-patches.gcc.gnu.org>
List-Unsubscribe: <http://gcc.gnu.org/mailman/options/gcc-patches>,
 <mailto:gcc-patches-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-patches/>
List-Post: <mailto:gcc-patches@gcc.gnu.org>
List-Help: <mailto:gcc-patches-request@gcc.gnu.org?subject=help>
List-Subscribe: <http://gcc.gnu.org/mailman/listinfo/gcc-patches>,
 <mailto:gcc-patches-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Mon, 29 Jun 2020 17:24:55 -0000

On 6/29/20 4:57 PM, Marek Polacek wrote:
> On Mon, Jun 29, 2020 at 09:51:57AM +0200, Martin Liška wrote:
>> On 6/26/20 9:34 PM, Marek Polacek via Gcc-patches wrote:
>>> As discussed last month:
>>> <https://gcc.gnu.org/pipermail/gcc-patches/2020-May/545879.html>
>>> it's time to change the C++ default to gnu++17.  I've committed the patch after
>>> testing x86_64-pc-linux-gnu and powerpc64le-unknown-linux-gnu.  Brace yourselves!
>>>
>>> Marek
>>>
>>
>> Just a small note that 510.parest_r SPEC 2017 benchmark can't be built now
>> with default changed to -std=c++17. The spec config needs to be adjusted.
> 
> Interesting, do you know why?  Does it use the register keyword?

Apparently it needs -fno-new-ttp-matching for successful compilation.
There's a reduced test-case I made:

cat fe.ii
template <int, int> class FiniteElement;
template <int, int> class DoFHandler;
class FETools {
   template <int dim, class InVector, class OutVector, int spacedim>
   void back_interpolate(const DoFHandler<dim, spacedim> &, const InVector &,
                         const FiniteElement<dim, spacedim> &, OutVector &);
   template <int dim, template <int> class DH, class InVector, class OutVector,
             int spacedim>
   void back_interpolate(const DH<dim> &, InVector,
                         const FiniteElement<dim, spacedim> &, OutVector);
};
template <int dim, int = dim> class DoFHandler;
template <int dim, int = dim> class FiniteElement;
template <int dim, class InVector, class OutVector, int spacedim>
void FETools::back_interpolate(const DoFHandler<dim, spacedim> &,
                                const InVector &,
                                const FiniteElement<dim, spacedim> &,
                                OutVector &) {}
template void FETools::back_interpolate(const DoFHandler<3> &, const float &,
                                         const FiniteElement<3> &, float &);

Martin

> 
> Marek
>