<AWT Dev> [OpenJDK 2D-Dev] RFR(XS): 8160721: Avoid deoptimizations in Font.equals.

Lindenmaier, Goetz goetz.lindenmaier at sap.com
Mon Jul 18 06:24:43 UTC 2016


Hi Volker, 

thanks for looking at this, and doing the test example!

Best regards,
  Goetz.

> -----Original Message-----
> From: Volker Simonis [mailto:volker.simonis at gmail.com]
> Sent: Freitag, 15. Juli 2016 12:09
> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
> Cc: Phil Race <philip.race at oracle.com>; awt-dev at openjdk.java.net; 2d-dev
> <2d-dev at openjdk.java.net>
> Subject: Re: [OpenJDK 2D-Dev] <AWT Dev> RFR(XS): 8160721: Avoid
> deoptimizations in Font.equals.
> 
> Hi Goetz,
> 
> it would be really interesting to see the use case where this has been
> a performance issue.
> 
> But even without that I agree with your comments in the bug. Phil's
> fear that you introduce an extra 'instanceof' check for the positive
> case is unfounded. I've attached a small example program to the bug
> which shows that the common case is the same for both version, only
> the uncommon version where the paramter is not a Font object is
> slightly more complicated in the original version because of the extra
> exception handling code.
> 
> So in general the change looks good!
> Please push it to the client repo.
> 
> Regards,
> Volker
> 
> 
> On Thu, Jul 7, 2016 at 9:04 AM, Lindenmaier, Goetz
> <goetz.lindenmaier at sap.com> wrote:
> > Hi,
> >
> > can I consider this reviewed?
> > Remi Forax and Phil Race had a look at this.
> >
> > Best regards,
> >  Goetz.
> >
> >> -----Original Message-----
> >> From: Lindenmaier, Goetz
> >> Sent: Montag, 4. Juli 2016 08:33
> >> To: 'Phil Race' <philip.race at oracle.com>; awt-dev at openjdk.java.net; 2d-
> dev
> >> <2d-dev at openjdk.java.net>
> >> Subject: RE: <AWT Dev> RFR(XS): 8160721: Avoid deoptimizations in
> >> Font.equals.
> >>
> >> Hi,
> >>
> >> Resending this to 2d-dev.
> >>
> >> Also, I made a new webrev considering Remi's comments:
> >> http://cr.openjdk.java.net/~goetz/wr16/8160721-deoptFont/webrev.02/
> >>
> >> Best regards,
> >>   Goetz.
> >>
> >>
> >> > -----Original Message-----
> >> > From: Phil Race [mailto:philip.race at oracle.com]
> >> > Sent: Freitag, 1. Juli 2016 19:35
> >> > To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; awt-
> >> > dev at openjdk.java.net
> >> > Subject: Re: <AWT Dev> RFR(XS): 8160721: Avoid deoptimizations in
> >> > Font.equals.
> >> >
> >> > Please resend this to 2d-dev. All font related API and implementation
> >> > is part of 2D, not AWT.
> >> >
> >> > -phil.
> >> >
> >> > On 7/1/2016 6:59 AM, Lindenmaier, Goetz wrote:
> >> > >
> >> > > Hi,
> >> > >
> >> > > This small fix improves performance of the C2 compiler.
> >> > >
> >> > > We see deoptimizations due to class casts in Font.equals.
> >> > > Use instanceof check instead of catching the exception.
> >> > >
> >> > > Please review this change:
> >> > >
> >> > > http://cr.openjdk.java.net/~goetz/wr16/8160721-deoptFont/
> >> > > <http://cr.openjdk.java.net/%7Egoetz/wr16/8160721-deoptFont/>
> >> > >
> >> > > Best regards,
> >> > >
> >> > >   Goetz.
> >> > >
> >


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