From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8025 invoked by alias); 3 Mar 2008 20:55:51 -0000 Received: (qmail 8016 invoked by uid 22791); 3 Mar 2008 20:55:50 -0000 X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 03 Mar 2008 20:55:33 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id m23KtU2o015582; Mon, 3 Mar 2008 15:55:30 -0500 Received: from omfg.slc.redhat.com (vpn-14-45.rdu.redhat.com [10.11.14.45]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m23KtSLB030550; Mon, 3 Mar 2008 15:55:29 -0500 Message-ID: <47CC6550.1090209@redhat.com> Date: Mon, 03 Mar 2008 20:55:00 -0000 From: Jeff Law User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Peter Bergner CC: Richard Sandiford , gcc-patches , "H.J. Lu" Subject: Re: [PATCH] PR35371 GCSE loses track of REG_POINTER attribute References: <20080225222624.GA26857@vervain.rchland.ibm.com> <87skzfzkvh.fsf@firetop.home> <1204052325.7014.2.camel@otta> <47C467BA.1090308@redhat.com> <1204240130.7376.16.camel@otta> <47CC4E4D.5040706@redhat.com> <1204573308.6969.8.camel@otta> In-Reply-To: <1204573308.6969.8.camel@otta> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org X-SW-Source: 2008-03/txt/msg00164.txt.bz2 Peter Bergner wrote: > On Mon, 2008-03-03 at 12:15 -0700, Jeff Law wrote: >>> Do you mean fix it up and then call it from more than just CSE? >>> Currently, the only call to reg_scan() isn't in a location that >>> will help me. >> No. I mean make it smarter. If you read the code it's amazingly >> simplistic and punts propagation of REG_POINTER for any pseudo >> that is set more than once. >> >> It shouldn't be terribly difficult to build a simple propagation >> engine that handles multiple sets. > > Sorry, making it "smarter" is what I meant by "fix it up". > My problem with it, as I mentioned in my previous note, is that > the only location it is currently called doesn't help me. > I guess what I was asking was there shouldn't be a problem > with me calling it from another location, correct? Ah. A misunderstanding on my part. I do recall some problems with passes substituting a pseudo without REG_POINTER set for a register with REG_POINTER set, so if you run it early, you might lose some REG_POINTER attributes. That's not a fatal problem -- the PA backend already knows to cope with this issue. And if the pass is safe, you ought to be able to just run it twice. Ideally propagation of REG_POINTER would use both the assignment to the pseudo and the use of the pseudo to try and determine if it's a pointer. Jeff