From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24220 invoked by alias); 10 May 2005 05:48:35 -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 23887 invoked by uid 48); 10 May 2005 05:48:02 -0000 Date: Tue, 10 May 2005 05:48:00 -0000 Message-ID: <20050510054802.23886.qmail@sourceware.org> From: "kazu at cs dot umass dot edu" To: gcc-bugs@gcc.gnu.org In-Reply-To: <20050509010537.21458.kazu@cs.umass.edu> References: <20050509010537.21458.kazu@cs.umass.edu> Reply-To: gcc-bugzilla@gcc.gnu.org Subject: [Bug tree-optimization/21458] VRP does not remove a conditional in a loop X-Bugzilla-Reason: CC X-SW-Source: 2005-05/txt/msg01292.txt.bz2 List-Id: ------- Additional Comments From kazu at cs dot umass dot edu 2005-05-10 05:47 ------- DOM leaves PHI nodes like # i_5 = PHI <1(0)>; Then SCEV gives a symbolic initial value like i_5 with the step being 1. So the information from SCEV is useless here. With a tcb-like pass ordering (running VRP after CCP, COPY-PROP, etc but before DOM), we don't see a degenerate PHI node like above. Then it's just a matter of making vrp_meet slightly aggressive on meeting two VR_RANGEs. -- What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|unassigned at gcc dot gnu |kazu at cs dot umass dot edu |dot org | Status|NEW |ASSIGNED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21458