From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by sourceware.org (Postfix) with ESMTP id 7BD94386F477 for ; Tue, 28 Apr 2020 15:16:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 7BD94386F477 Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-237-cFGIyZl9MACsE_A_T4RKhg-1; Tue, 28 Apr 2020 11:16:26 -0400 X-MC-Unique: cFGIyZl9MACsE_A_T4RKhg-1 Received: by mail-qv1-f71.google.com with SMTP id 65so22915290qva.17 for ; Tue, 28 Apr 2020 08:16:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=gJYd0DcS1A7ObnA4G+o/7IANYsy4bHINYNll1LyAiV4=; b=XK8v4AcgDQ6RX9/Q1eGcjo3WeAKJDl6pPBz4AXgDuYj5Wd2yEg4dWo0Ejv+desGEi/ qWBoHbQPVvjdF4W0/MKzbA11Ne1zPEj/Y2nmnYkk9HgwsvmMe7MM8jb63wd+mAOvmS/U N+AwIjZP+jcp0sMseU7FR2fHiZVANvHGpkwt/7ZVDZYo1m87b4jZ1oZS13IU5itZvOp4 1JEDJlp1CO5wNM0NcFBV7EOuLQYUOzduoGKyNzKCjMroZs4Acg8Yru/qUmrEJNeQgLbp nHEGIqZ6oLu7iG8lSVX6TsGbQ4JWtSCeAp8PoKdbCNuC7c44sHIjRwNjIJE3hA68R3hp z8OQ== X-Gm-Message-State: AGi0Pubi8tacEmZpDiQiztiIUC/XwXJ/ZnpIp0nM+KLlsaaGqoUXlbJE 52Nz0t2R4Wi2lfSNcNsB/BKMsFY3PcSimYggJKSRMYSrjD7avRf5JkcFy5a5dTxVD5P9jUyZ1+p pspNSjRCWrHigojuu9A== X-Received: by 2002:a37:6393:: with SMTP id x141mr26451787qkb.179.1588086985399; Tue, 28 Apr 2020 08:16:25 -0700 (PDT) X-Google-Smtp-Source: APiQypLrH8jHiH3mdhr7AftNJczVFYCtbcIqs5/mD8oSy1lWclutjxYRcPLlNXVpw+kvSxwnt//clQ== X-Received: by 2002:a37:6393:: with SMTP id x141mr26451722qkb.179.1588086984678; Tue, 28 Apr 2020 08:16:24 -0700 (PDT) Received: from [192.168.1.148] (209-6-216-142.s141.c3-0.smr-cbr1.sbo-smr.ma.cable.rcncustomer.com. [209.6.216.142]) by smtp.gmail.com with ESMTPSA id m40sm14692225qtc.33.2020.04.28.08.16.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Apr 2020 08:16:24 -0700 (PDT) Subject: Re: [PATCH] s390: Fix up -Wpsabi diagnostcs + analysis [PR94704] To: Jakub Jelinek , Andreas Krebbel Cc: gcc-patches@gcc.gnu.org, Ulrich.Weigand@de.ibm.com References: <20200428121302.GM2424@tucnak> <20200428143807.GQ2424@tucnak> From: Jason Merrill Message-ID: Date: Tue, 28 Apr 2020 11:16:23 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200428143807.GQ2424@tucnak> Content-Language: en-US X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-15.9 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Apr 2020 15:16:29 -0000 On 4/28/20 10:38 AM, Jakub Jelinek wrote: > On Tue, Apr 28, 2020 at 04:23:24PM +0200, Andreas Krebbel wrote: >> Our ABI doesn't specify anything regarding C++ so there is nothing in there which really conflicts >> with that. I assume these things will be part of a cross-platform C++ ABI instead? I don't see a way >> to add this to our platform ABI without introducing C++ in general there. >> >> Since "no_unique_address" is a new feature we want to pick whatever is most efficient and matches >> what other archs do. Passing F, G, J, K in FPRs looks reasonable to me. > > Ok, will tweak the patch then once the powerpc+generic one is finalized. > >> Given that this is something which hasn't been covered by the ABI so far I'm not sure we really need >> a -Wpsabi warning for that. > > But [[no_unique_address]] has been introduced already in GCC 9, so e.g. in > the powerpc64le patch I want to warn users about the ABI incompatibility > when padding those. > Your call though. Though C++20 support is still highly experimental, we're not trying to maintain compatibility. >> Btw. is the no_unique_address flag visible also in Dwarf? Probably it is enough for GDB to just >> observe the effect of it to decide how to pass arguments?! I agree that's probably enough. Jason