From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 6ED803854098 for ; Mon, 12 Dec 2022 14:53:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6ED803854098 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1670856800; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=r3EOZEYPbwcxBSEd1xvWoKdV1qDiD/+ORACb9Qe5iVs=; b=II+4eTCwq5MWEJSAIHrfLvlen8c5O0/qv9cdplWq/nJHr7Rx9jolQWWVN4niekH2KkVr1S qBoKCOqf+TvbIL3mBfJlW6h0bBsWQsdz2DPI6E066FKT2np7ejl+OnUGEwjTfyhqsxtgSr vvAdz1cKIoiBO4NFVr91+OyH7EZag94= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-624-PBQSG7oQMNmRNzmZ6RQ9JA-1; Mon, 12 Dec 2022 09:53:17 -0500 X-MC-Unique: PBQSG7oQMNmRNzmZ6RQ9JA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9885F29AA384; Mon, 12 Dec 2022 14:53:16 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.195.114]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 56B4214152F4; Mon, 12 Dec 2022 14:53:16 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 2BCErBLt4143338 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 12 Dec 2022 15:53:11 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 2BCErA9b4143336; Mon, 12 Dec 2022 15:53:10 +0100 Date: Mon, 12 Dec 2022 15:53:09 +0100 From: Jakub Jelinek To: Jonathan Wakely Cc: Alejandro Colomar , Martin =?utf-8?B?TGnFoWth?= , gcc@gcc.gnu.org, GNU C Library Subject: Re: Missing optimization: mempcpy(3) vs memcpy(3) Message-ID: Reply-To: Jakub Jelinek References: <8f9d61cf-14a5-4099-e2b6-7c8cac47a28b@suse.cz> <2baeaa96-b111-1f1c-ddf5-928edc8b3588@gmail.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Mon, Dec 12, 2022 at 02:48:35PM +0000, Jonathan Wakely wrote: > On Mon, 12 Dec 2022 at 14:09, Alejandro Colomar wrote: > > On 12/12/22 14:56, Jakub Jelinek wrote: > > > > I think that is the case, plus the question if one can use a non-standard > > > function to implement a standard function (and if it would be triggered > > > by seeing an expected prototype for the non-standard function). > > > > I guess implementing a standard function by calling a non-standard one is fine. > > The implementation is free to do what it pleases, as long as it provides the > > expected interface. > > Even if the program provides a function called mempcpy? And even does something completely different... Jakub