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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 6EE1D3858D28 for ; Tue, 23 Nov 2021 16:20:04 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6EE1D3858D28 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-317-hnMzz2KJMYarSRCThOtDDQ-1; Tue, 23 Nov 2021 11:19:58 -0500 X-MC-Unique: hnMzz2KJMYarSRCThOtDDQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4839C10168C7; Tue, 23 Nov 2021 16:19:57 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E3F3E19C59; Tue, 23 Nov 2021 16:19:56 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.16.1/8.16.1) with ESMTPS id 1ANGJsbq2111816 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 23 Nov 2021 17:19:54 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.16.1/8.16.1/Submit) id 1ANGJrqc2111815; Tue, 23 Nov 2021 17:19:53 +0100 Date: Tue, 23 Nov 2021 17:19:53 +0100 From: Jakub Jelinek To: Siddhesh Poyarekar Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH 06/10] tree-object-size: Support dynamic sizes in conditions Message-ID: <20211123161953.GC2646553@tucnak> Reply-To: Jakub Jelinek References: <20211109190137.1107736-1-siddhesh@gotplt.org> <20211109190137.1107736-7-siddhesh@gotplt.org> <20211123151252.GZ2646553@tucnak> <773d3a85-b78c-c67e-c190-b9b128d3738b@gotplt.org> <20211123155254.GA2646553@tucnak> <7207a9c6-f134-651d-b9d6-e72bb2d8b0be@gotplt.org> MIME-Version: 1.0 In-Reply-To: <7207a9c6-f134-651d-b9d6-e72bb2d8b0be@gotplt.org> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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=-5.7 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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, 23 Nov 2021 16:20:05 -0000 On Tue, Nov 23, 2021 at 09:30:30PM +0530, Siddhesh Poyarekar wrote: > On 11/23/21 21:22, Jakub Jelinek wrote: > > Evaluating __bdos in both passes is undesirable, certainly for the same > > SSA_NAME, but even for different SSA_NAMEs, if everything is done in a > > single pass it can easily share temporaries (object sizes for SSA_NAMEs it > > uses), while if some __bdos is evaluated early and other late, we'll need to > > hope further optimizations CSE those. > > OK, then treat __bdos like __bos in objsz1, adding MIN?MAX for subobjects > and full evaluation in objsz2? Yes. It is not perfect, but unfortunately it is hard to get perfect results. The subobject stuff for __bos has been designed when GCC wasn't doing such optimizations, later MEM_REF has been introduced and we really can't prevent all those optimizations just because there could be a subobject __bos somewhere that cares about that. Jakub