RFR: 8165661: SPECjvm2008-crypto.signverify regression in 9-b105

[Rahul Raghavan]

Hi,

Thanks for review Vladimir, Tobias, Roland.
Please note the required new enhancement is created and linked.
https://bugs.openjdk.java.net/browse/JDK-8168481

Thanks,
Rahul

> -----Original Message-----
> From: Tobias Hartmann
> Sent: Friday, October 21, 2016 11:57 AM
> To: Rahul Raghavan; hotspot-compiler-dev at openjdk.java.net
> Subject: Re: RFR: 8165661: SPECjvm2008-crypto.signverify regression in 9-b105
> 
> Hi Rahul,
> 
> On 20.10.2016 20:24, Rahul Raghavan wrote:
> > Hi,
> >
> > Please review following patch for JDK- 8165661.
> > <webrev.00> :  http://cr.openjdk.java.net/~rraghavan/8165661/webrev.00/
> >
> > 1. <bug details> : https://bugs.openjdk.java.net/browse/JDK-8165661
> > Performance regression reported with Internal run benchmark harness (SPECjvm2008-crypto.signverify) for x86_64 with JDK9-b105
> build onwards.
> >
> > 2. Found following change done as sub-part of old JDK-8145322 Enhancement is the root cause of the reported Performance
> regression -
> >         [the (CastII (AddI x const)) -> (AddI (CastII x) const) transformation change block in CastIINode::Ideal() - castnode.cpp]
> >
> >       (https://bugs.openjdk.java.net/browse/JDK-8145322 - Code generated from unsafe loops can be slightly improved)
> >       (http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/c8b709902e0e)
> >       (http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2015-December/020381.html)
> >
> > 3. Understood there was no performance numbers with old 8145322 fix.
> > But now with proposed <webrev.00> change (reverting old sub part of 8145322),
> >   got no jprt functional failures, no other performance regressions and confirmed reported signverify regression is solved.
> >
> > 4. So to go forward as Roland W suggested, request for review and approval of this proposed <webrev.00> to close this 8165661.
> > Afterwards I will create a  new separate enhancement CR to investigate
> >   why this reverted old 8145322 part caused issues and for a possible better version of the same.
> 
> Looks good to me! Please link the new enhancement to this bug.
> 
> Best regards,
> Tobias
> 
> >
> >
> > Thanks,
> > Rahul
> >