From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18929 invoked by alias); 13 May 2003 18:35:57 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 18690 invoked from network); 13 May 2003 18:35:54 -0000 Received: from unknown (HELO piper.synopsys.com) (204.176.21.196) by sources.redhat.com with SMTP; 13 May 2003 18:35:54 -0000 Received: (from jbuck@localhost) by piper.synopsys.com (8.11.6/8.11.6) id h4DIZij18892; Tue, 13 May 2003 11:35:44 -0700 Date: Tue, 13 May 2003 18:35:00 -0000 From: Joe Buck To: law@redhat.com Cc: Diego Novillo , Zack Weinberg , Michael Matz , "gcc@gcc.gnu.org" Subject: Re: Dead-code elimination can't remove string copy insns? Message-ID: <20030513113543.A18869@synopsys.com> References: <1052848240.27232.407.camel@frodo.toronto.redhat.com> <200305131802.h4DI25Ea012586@speedy.slc.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <200305131802.h4DI25Ea012586@speedy.slc.redhat.com>; from law@redhat.com on Tue, May 13, 2003 at 12:02:05PM -0600 X-SW-Source: 2003-05/txt/msg01341.txt.bz2 On Tue, May 13, 2003 at 12:02:05PM -0600, law@redhat.com wrote: > In message <1052848240.27232.407.camel@frodo.toronto.redhat.com>, Diego Novillo > writes: > >Now, if we could also get rid of those pesky labels. You mentioned > >something about that, but I forget what. > Well, it's simply a matter of building a use count for the labels. As > we remove GOTO_EXPRs we decrement the count. I don't know anything about the code in question, but is it certain that the cost of maintaining, incrementing, and decrementing reference counts is less than the cost of doing a sweep at the end to clean up unused cruft? Reference counting is not necessarily cheap.