From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-return-71293-listarch-gcc=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 10037 invoked by alias); 1 Apr 2003 16:11:15 -0000
Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Archive: <http://gcc.gnu.org/ml/gcc/>
List-Post: <mailto:gcc@gcc.gnu.org>
List-Help: <http://gcc.gnu.org/ml/>
Sender: gcc-owner@gcc.gnu.org
Received: (qmail 10026 invoked from network); 1 Apr 2003 16:11:14 -0000
Received: from unknown (HELO gauvain.u-strasbg.fr) (130.79.74.5)
  by sources.redhat.com with SMTP; 1 Apr 2003 16:11:14 -0000
Received: from pop by gauvain.u-strasbg.fr with local (Exim 3.36 #1 (Debian))
	id 190OLw-0007Ht-00; Tue, 01 Apr 2003 18:11:12 +0200
Date: Tue, 01 Apr 2003 17:05:00 -0000
To: Jan Hubicka <jh@suse.cz>
Cc: gcc@gcc.gnu.org
Subject: Re: [RFC] CFG hooks for rtl/tree specificities
Message-ID: <20030401161112.GD24512@gauvain.u-strasbg.fr>
References: <20030401145007.GA25362@gauvain.u-strasbg.fr> <20030401154607.GF904@kam.mff.cuni.cz>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20030401154607.GF904@kam.mff.cuni.cz>
User-Agent: Mutt/1.4i
From: =?iso-8859-1?Q?Pop_S=E9bastian?= <pop@gauvain.u-strasbg.fr>
X-SW-Source: 2003-04/txt/msg00036.txt.bz2

On Tue, Apr 01, 2003 at 05:46:07PM +0200, Jan Hubicka wrote:
> 
> This looks nice.
> It would be interesting to think about what operations do we really need
> - for instance split_edge should be probably implementable already via
> the primitive operations (basic block creation, edge redirection).  Our

Yes, the split_edge function is trivially implemented at the tree level:

basic_block
tree_split_edge (edge_in)
     edge edge_in;
{
  basic_block new_bb, dest;
  
  /* Abnormal edges cannot be split.  */
  if (edge_in->flags & EDGE_ABNORMAL)
    abort ();
  
  dest = edge_in->dest;
  new_bb = create_bb ();
  redirect_edge_succ  (edge_in, new_bb);
  make_edge (new_bb, dest, EDGE_FALLTHRU);
  return new_bb;
}

except "create_bb" all the other functions are CFG generic, making the split_edge
a good candidate for the CFG API.  At RTL level the split_edge function deals
with insns at this moment.

> current API is not 100% ready for that so we will probably need cleanup
> on the way.
> 
> I would be happy about switching to the hooks first and leaving it to me
> to cleanup the APIs if you preffer.
> 
Yes, thanks.

Sebastian