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 B45563857B96 for ; Fri, 1 Jul 2022 18:53:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org B45563857B96 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-274-h1v0XE4bOgmLWbDwSJhIzA-1; Fri, 01 Jul 2022 14:53:17 -0400 X-MC-Unique: h1v0XE4bOgmLWbDwSJhIzA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 937A8101A58E; Fri, 1 Jul 2022 18:53:17 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.30]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4C776C4C7A0; Fri, 1 Jul 2022 18:53:17 +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 261IrET31652972 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Fri, 1 Jul 2022 20:53:15 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 261IrD6h1652971; Fri, 1 Jul 2022 20:53:13 +0200 Date: Fri, 1 Jul 2022 20:53:13 +0200 From: Jakub Jelinek To: Aldy Hernandez Cc: GCC patches , Andrew MacLeod , Richard Sandiford Subject: Re: [RFC] trailing_wide_ints with runtime variable lengths Message-ID: Reply-To: Jakub Jelinek References: <20220629092157.230287-1-aldyh@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 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=-3.8 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_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) 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: Fri, 01 Jul 2022 18:53:23 -0000 On Fri, Jul 01, 2022 at 07:43:28PM +0200, Aldy Hernandez wrote: > You can still say N=255 and things continue to work as they do now, since > m_len[] is still statically determined. The only difference is that before, > the size of the structure would be 2+1+255+sizeof(int) whereas now it would > be 1 more because of the byte I'm using for num_elements. So, what N do you want to use for SSA_NAME_RANGE_INFO? N=255 wouldn't be very space efficient especially if the common case is a single range or two. For such cases making e.g. m_len not an embedded array, but pointer to somewhere after the HOST_WIDE_INT array in the same allocation would be better. Jakub