This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: CFG branch merge 5 - remove PROP_ALLOW_CFG_CHANGES
- From: Jan Hubicka <jh at suse dot cz>
- To: Richard Henderson <rth at redhat dot com>, Jan Hubicka <jh at suse dot cz>, gcc-patches at gcc dot gnu dot org, gcc-pdo at atrey dot karlin dot mff dot cuni dot cz, patches at x86-64 dot org
- Date: Wed, 13 Mar 2002 21:24:35 +0100
- Subject: Re: CFG branch merge 5 - remove PROP_ALLOW_CFG_CHANGES
- References: <20020226163447.GC14496@atrey.karlin.mff.cuni.cz> <20020227123506.E29553@redhat.com> <20020228082658.GB706@atrey.karlin.mff.cuni.cz> <20020228093856.C30215@redhat.com> <20020228201152.GA20347@atrey.karlin.mff.cuni.cz> <20020228122856.A30448@redhat.com> <20020228203114.GB20347@atrey.karlin.mff.cuni.cz> <20020228130853.A30470@redhat.com>
> On Thu, Feb 28, 2002 at 09:31:14PM +0100, Jan Hubicka wrote:
> > Would this be OK if I mplement the loop at cfg_cleanup time?
>
> I don't thinnk I know quite what you're suggesting.
> Show me the patch.
>
> > I just felt that the optimization is bit expensive given the benefit
> > it brings. What kind of problems it brought to pa except the pesimized
> > code?
>
> My memory is apparently faulty. I thought it was submitted
> to address some problem other than performance, but no.
>
> http://gcc.gnu.org/ml/gcc-patches/2001-07/msg01832.html
OK, this issue should be tracked down by last cfg_cleanup changes.
Hope that now this patch is ready for review. (it saves quite some
time from liveness rebuilds on combine.c)
Honza
>
> Although I do seem to recall problems in, e.g. if_convert
> dealing with empty basic blocks, I can't find anything
> more specific.
>
>
> r~