On Fri, Apr 05, 2024 at 03:46:30PM -0600, Jeff Law wrote:
>
>
> On 4/5/24 3:27 PM, Segher Boessenkool wrote:
> > Hi!
> >
> > On Wed, Apr 03, 2024 at 01:07:41PM +0200, Richard Biener wrote:
> > > The following avoids re-walking and re-combining the instructions
> > > between i2 and i3 when the pattern of i2 doesn't change.
> > >
> > > Bootstrap and regtest running ontop of a reversal of
> > > r14-9692-g839bc42772ba7a.
> >
> > Please include that in the patch (or series, preferably).
> >
> > > It brings down memory use frmo 9GB to 400MB and compile-time from
> > > 80s to 3.5s. r14-9692-g839bc42772ba7a does better in both metrics
> > > but has shown code generation regressions across acrchitectures.
> > >
> > > OK to revert r14-9692-g839bc42772ba7a?
> >
> > No.
> >
> > The patch solved a very real problem. How does your replacement handle
> > that? You don't say. It looks like it only battles symptoms a bit,
> > instead :-(
> But that patch very clearly created new problems in the process. I would
> argue that it was a step backwards given that we're in stage4.
Yeah. E.g. PR114518 and PR114522, both P1s.
Jakub
