[PATCH] proper dataflow block visitation order

[Richard Guenther]

On Feb 9, 2008 5:22 PM, Kenneth Zadeck <zadeck@naturalbridge.com> wrote:
>
> Paolo Bonzini wrote:
> > Kenneth Zadeck wrote:
> >> Paolo Bonzini wrote:
> >>> Kenneth Zadeck wrote:
> >>>> Paolo Bonzini wrote:
> >>>>>> Bootstrapped on i686 with c/c++ and no regression.
> >>>>>> While this is not exactly a regression,
> >>>>>> I'd like to commit this to 4.3 -
> >>>>> The patch may be okay for 4.3 with the changes Steven suggested.
> >>>>> However, I'd like to see also an assembly language output comparison
> >>>>> for some .i files (e.g. cc1 or SPEC).
> >>>>>
> >>>>> Paolo
> >>>> we are in lock down mode.  i believe that only one of the release
> >>>> managers can approve this for 4.3.
> >>> It depends whether you consider it a regression.  All maintainers can
> >>> approve regression fixes.
> >>>
> >>> Paolo
> >> i tend to be more conservative here:   4 percent extra node visits is
> >> not significant.  there is no test case that will fail because of this
> >> issue, nor any code that will be generated any differently.
> >
> > I see -- indeed I asked for assembly language comparison because you
> > don't expect difference.  Mark in the past was more permissive for
> > compile-timgressions; the current release managers might disagree.
> >
> > Paolo
>
> note that seonbae claims a 4% difference in number of node visits.  this
> will translate into almost no significant difference in compile time.
>
> I am all for the patch going into 4.4 with stevens changes.   But I do
> not see the need for pushing this on what is now a compiler with no p1
> regressions.

Please do not apply this to trunk right now, but wait for stage1.  If it turns
out to be safe and worth it, you can consider backporting it for 4.3.1.

Thanks,
Richard.