From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14209 invoked by alias); 22 Feb 2006 15:24:46 -0000 Received: (qmail 14185 invoked by alias); 22 Feb 2006 15:24:42 -0000 Date: Wed, 22 Feb 2006 15:24:00 -0000 Message-ID: <20060222152442.14184.qmail@sourceware.org> X-Bugzilla-Reason: CC References: Subject: [Bug tree-optimization/26406] Fowardprop does harm for VRP to figure out if a point is non zero In-Reply-To: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "law at redhat dot com" 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 X-SW-Source: 2006-02/txt/msg02529.txt.bz2 List-Id: ------- Comment #9 from law at redhat dot com 2006-02-22 15:24 ------- Subject: Re: Fowardprop does harm for VRP to figure out if a point is non zero On Wed, 2006-02-22 at 10:32 +0000, rguenth at gcc dot gnu dot org wrote: > > ------- Comment #4 from rguenth at gcc dot gnu dot org 2006-02-22 10:32 ------- > find_equivalent_equality_comparison through simplify_cond, > forward_propagate_into_cond does this. I have a patch which restricts forwprop > to using single-use names. Though I wonder if this is appropriate and we > rather should teach VRP to infer range information for D.2354_2 from a_3. Please don't. I'm already aware of this issue and looking at a better solution. jeff -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26406