Re: [PING][PATCH][REVISED] Fix PR middle-end/PR28690, modify swap_commutative_operands_p

["Richard Guenther" <richard dot guenther at gmail dot com>]

On 7/13/07, H.J. Lu <hjl@lucon.org> wrote:
> On Fri, Jul 13, 2007 at 11:43:22PM +0200, Paolo Bonzini wrote:
> >
> > >I don't know even know which changes should be guarded by a target
> > >macro since there are quite a few independent changes in that
> > >patch.
> >
> > Two hunks are bugfixes.  The other two (in rtlanal.c) are the only
> > targets that could affect performance but, again, it's just luck or bad
> > luck.
>
> Then bug fixes should be submitted with testcases separately from
> the performance change for Power 6.
>
> >
> > I don't see the addressing modes in x86 that well tuned.  Surely not the
> > tuning that Pat and Peter are doing, and not a kind of tuning that could
> > be incompatible.
> >
>
> We are working hard to make sure that gcc won't getting worse on
> x86 :-(.

There is more volatileness in x86 performance numbers already than
the predicted change by this.  For example I see both leslie3d and
GemmsFDTD dropped 30% / 20% around Jul 5th.  I would rather
wait for a quieter period to analyze the cummulative effect of all
the changes we piled up.  Fixing them afterwards is probably better
than trying to block changes that cannot definitely explain the
seen change.

Richard.