From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20496 invoked by alias); 17 Oct 2007 16:59:35 -0000 Received: (qmail 20461 invoked by uid 48); 17 Oct 2007 16:59:26 -0000 Date: Wed, 17 Oct 2007 16:59:00 -0000 Message-ID: <20071017165926.20460.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/32921] [4.3 Regression] Revision 126326 causes 12% slowdown In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "pinskia at gcc dot gnu dot org" 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: 2007-10/txt/msg01550.txt.bz2 ------- Comment #13 from pinskia at gcc dot gnu dot org 2007-10-17 16:59 ------- Can someone explain this may_alias behavior: so we have in the IR: # VUSE D.892_19 = qav.data; D.893_20 = (real8[0:] *) D.892_19; in may_alias we get a constraint of: D.892_19 = qav D.893_20 = D.892_19 Isn't this wrong? D. 892_19 shouldn't just point to anywhere? Inside the loop we get: # VUSE D.903_30 = (*D.893_20)[D.902_29]; Which obviously shows that the vops are wrong. -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |dberlin at gcc dot gnu dot | |org Keywords| |missed-optimization http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32921