From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21828 invoked by alias); 1 Nov 2012 23:00:38 -0000 Received: (qmail 21040 invoked by uid 48); 1 Nov 2012 23:00:08 -0000 From: "ebotcazou at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/55142] [4.8 Regression] internal compiler error: in plus_constant, at explow.c:88 Date: Thu, 01 Nov 2012 23:00:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ebotcazou at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: ebotcazou at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.8.0 X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2012-11/txt/msg00090.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55142 --- Comment #16 from Eric Botcazou 2012-11-01 23:00:06 UTC --- > The patch compiles testcase, but totally miscompiles glibc. Ouch. Then this means that the existing non-PIC code is wrong as well. > I think the bug is in unsigned array index computation as > shown in Comment 7. dyn->d_tag is signed type and Pmode > != ptr_mode here. Possibly, you must be extra careful with these kinds of awkward setups. We already had similar issues in the past (MEM_REF expansion on SPARC64, array indexes on IA-64/VMS) but the bugs were in the RTL expansion. I'll dig.