From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31932 invoked by alias); 25 Jan 2005 11:02:59 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 31888 invoked by alias); 25 Jan 2005 11:02:49 -0000 Date: Tue, 25 Jan 2005 11:02:00 -0000 Message-ID: <20050125110249.31887.qmail@sourceware.org> From: "sebastian dot pop at cri dot ensmp dot fr" To: gcc-bugs@gcc.gnu.org In-Reply-To: <20041121145949.18595.pinskia@gcc.gnu.org> References: <20041121145949.18595.pinskia@gcc.gnu.org> Reply-To: gcc-bugzilla@gcc.gnu.org Subject: [Bug tree-optimization/18595] [4.0 Regression] IV-OPTS is O(N^3) X-Bugzilla-Reason: CC X-SW-Source: 2005-01/txt/msg03661.txt.bz2 List-Id: ------- Additional Comments From sebastian dot pop at cri dot ensmp dot fr 2005-01-25 11:02 ------- Subject: Re: [4.0 Regression] IV-OPTS is O(N^3) rakdver at atrey dot karlin dot mff dot cuni dot cz wrote: > > (*) I hope; scev is a mess of mutualy recursive functions -- > analyze_scalar_evolution calling number_of_iterations calling > instantiate_parameters calling analyze_scalar_evolution again, with > instantiate_parameters hacked so that the infinite cycle cannot occur is > my favourite one. Nobody can say anything sure about behavior of scev > -- it is not even well defined what analyze_scalar_evolutions will > return to you, It returns to you an evolution that might contain SSA_NAMEs. > unless you call instantiate_parameters or resolve_mixers > on the result. > And once you call instantiate_parameters on the result you're guaranteed that what you get does contain only determined constants, or otherwise the result is chrec_dont_know. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18595