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Date: Mon, 05 Nov 2007 00:33:00 -0000
From: "Andrew Pinski" <pinskia@gmail.com>
To: "Jakub Jelinek" <jakub@redhat.com>
Subject: Re: [PATCH] Allow DCE of const or pure calls
Cc: "Mark Mitchell" <mark@codesourcery.com>,  	"Eric Botcazou" <ebotcazou@libertysurf.fr>, gcc-patches@gcc.gnu.org
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On 11/4/07, Jakub Jelinek <jakub@redhat.com> wrote:
> On Sun, Nov 04, 2007 at 04:11:11PM -0800, Mark Mitchell wrote:
> > Eric Botcazou wrote:
> > >> 2007-11-02  Jakub Jelinek  <jakub@redhat.com>
> > >>
> > >>    * dce.c (deletable_insn_p): Make const or pure calls deletable.
> > >
> > > Note that flow.c didn't delete these calls (unless inside libcalls) so I'm not
> > > sure we want this for 4.3.

At one point, we used to put pure/const functions in libcalls but we
don't after:
http://gcc.gnu.org/ml/gcc-patches/2005-07/msg01198.html

So I think this is fixing a regression from 3.4 on a RTL level optimization.

-- Pnski