From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32212 invoked by alias); 3 Apr 2007 15:48:08 -0000 Received: (qmail 32153 invoked by alias); 3 Apr 2007 15:47:53 -0000 Date: Tue, 03 Apr 2007 15:48:00 -0000 Message-ID: <20070403154753.32152.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug debug/31412] [4.3] inf loop/long compile time, time spent in var-tracking.c In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "zadeck at naturalbridge 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: 2007-04/txt/msg00219.txt.bz2 ------- Comment #14 from zadeck at naturalbridge dot com 2007-04-03 16:47 ------- Subject: Re: [4.3] inf loop/long compile time, time spent in var-tracking.c steven at gcc dot gnu dot org wrote: > ------- Comment #13 from steven at gcc dot gnu dot org 2007-04-03 16:40 ------- > So this may be a non-monotonous dataflow problem...? > > Do we have the dataflow equations of the var-tracking problem somewhere? It'd > be interesting to check them against the actual implementation. > > > this is a pretty complex problem. I gave it a cursory once over and it looks like the problem may not terminate if the location (stack offset) of a variable is not the same on all paths into a block. (the code may be different than the comments and i did just scan this) I assume that this case has a "bug" where a variable appears to be at a different location coming across an exception edge. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31412