From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 83811 invoked by alias); 12 Oct 2015 23:27:32 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 83798 invoked by uid 89); 12 Oct 2015 23:27:31 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 12 Oct 2015 23:27:30 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 58AD28F2E4; Mon, 12 Oct 2015 23:27:29 +0000 (UTC) Received: from bigtime.twiddle.net (ovpn-113-98.phx2.redhat.com [10.3.113.98]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t9CNRRHU026211; Mon, 12 Oct 2015 19:27:28 -0400 Subject: Re: [PATCH 8/9] Add TARGET_ADDR_SPACE_ZERO_ADDRESS_VALID To: Richard Biener References: <1444280375-20866-1-git-send-email-rth@redhat.com> <1444280375-20866-9-git-send-email-rth@redhat.com> <5616DBBE.9080309@redhat.com> Cc: GCC Patches From: Richard Henderson Message-ID: <561C41DD.5000505@redhat.com> Date: Mon, 12 Oct 2015 23:27:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2015-10/txt/msg01184.txt.bz2 On 10/12/2015 09:10 PM, Richard Biener wrote: >>> The check_loadstore change should instead have adjusted the >>> flag_delete_null_pointer_checks guard in >>> infer_nonnull_range_by_dereference. >> >> >> Nope, that doesn't work. You have to wait until you see the actual MEM >> being dereferenced before you can look at it's address space. > > Well, as we are explicitely looking for the pointer 'op' we know the > address-space > beforehand, no? TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (op)))? No. We don't even know what type we're looking for; we're merely looking for any use of NULL within any memory reference within STMT. Specifically, when we're not looking for a specific SSA_NAME (which would be properly typed), we always pass in a plain (void *)0: bool by_dereference = infer_nonnull_range_by_dereference (stmt, null_pointer_node); r~