From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4188 invoked by alias); 2 Jul 2010 19:49:48 -0000 Received: (qmail 3863 invoked by uid 48); 2 Jul 2010 19:49:24 -0000 Date: Fri, 02 Jul 2010 19:49:00 -0000 Message-ID: <20100702194924.3862.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug middle-end/44790] Bootstrap fails after MEM-REF merge In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "sje at cup dot hp dot com" 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: 2010-07/txt/msg00238.txt.bz2 ------- Comment #1 from sje at cup dot hp dot com 2010-07-02 19:49 ------- This may be related to &x + CST folding. The bug only happens at -O1 or above. I think I forgot to mention that in the original bug report. When I look at the expand dump and the comparision to 123 I see: (insn 17 16 18 3 x.c:8 (set (reg:DI 348) (zero_extend:DI (subreg/s/v:SI (reg/v/f:DI 339 [ ap+-4 ]) 4))) -1 (nil)) (insn 18 17 19 3 x.c:8 (set (reg/f:DI 347) (plus:DI (reg:DI 348) (const_int 4 [0x4]))) -1 (nil)) (insn 19 18 20 3 x.c:9 (set (reg:SI 349) (mem:SI (reg/f:DI 347) [0 MEM[(int *)ap_1 + 4B]+0 S4 A32])) -1 (nil)) (insn 20 19 21 3 x.c:9 (set (reg:BI 350) (eq:BI (reg:SI 349) (const_int 123 [0x7b]))) -1 (nil)) Instruction 17, where we set r348 to zero_extend of r339 looks wrong. We need to do a pointer extend here, I.e. (unspec 24) go generate an addp4. r349 is not a valid pointer after instruction 17 and this generates the fault. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44790