[8u] RFR for backport of JDK-8158012: Use SW prefetch instructions instead of BIS for allocation prefetches on SPARC Core C4

[Poonam Parhar]

Hello Muthu,

The changes look good. One minor nit - please remove '.' at the end of the comment at line 144 in vm_version_sparc.cpp:

144           // Use BIS instruction for TLAB allocation prefetch.
145           // on Niagara plus processors other than those based on CoreS4

Also, please update the copyright year for both the files.

Thanks,
Poonam

> -----Original Message-----
> From: Muthusamy Chinnathambi
> Sent: Tuesday, July 25, 2017 2:14 AM
> To: Vladimir Kozlov; hotspot-dev at openjdk.java.net
> Subject: RE: [8u] RFR for backport of JDK-8158012: Use SW prefetch
> instructions instead of BIS for allocation prefetches on SPARC Core C4
> 
> May I please get a second review for this change.
> 
> Thanks,
> Muthusamy C
> 
> -----Original Message-----
> From: Vladimir Kozlov
> Sent: Monday, July 24, 2017 9:52 PM
> To: Muthusamy Chinnathambi <muthusamy.chinnathambi at oracle.com>;
> hotspot-dev at openjdk.java.net
> Subject: Re: [8u] RFR for backport of JDK-8158012: Use SW prefetch
> instructions instead of BIS for allocation prefetches on SPARC Core C4
> 
> This looks good.
> 
> Thanks,
> Vladimir
> 
> On 7/23/17 11:56 PM, Muthusamy Chinnathambi wrote:
> > Hi Vladimir,
> >
> > Thanks for the review.
> > Please find the updated webrev at
> > http://cr.openjdk.java.net/~shshahma/Muthu/8158012/webrev.01/
> >
> > Regards,
> > Muthusamy C
> >
> > -----Original Message-----
> > From: Vladimir Kozlov
> > Sent: Friday, July 21, 2017 4:38 AM
> > To: Muthusamy Chinnathambi <muthusamy.chinnathambi at oracle.com>;
> > hotspot-dev at openjdk.java.net
> > Subject: Re: [8u] RFR for backport of JDK-8158012: Use SW prefetch
> > instructions instead of BIS for allocation prefetches on SPARC Core
> C4
> >
> > The indent for next comment line in vm_version_sparc.cpp is off:
> >
> > // Use BIS instr
> >
> > And AllocatePrefetchStyle set to 3 should be outside new check
> (should
> > be set for both cases). In JDK 9 there is following code which set it
> > for AllocatePrefetchInstr == 1 which JDK8 does not have:
> >
> >
> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/file/eebdc7acebd4/src/cpu
> > /sparc/vm/vm_version_sparc.cpp#l126
> >
> > thanks,
> > Vladimir
> >
> > On 7/20/17 12:24 AM, Muthusamy Chinnathambi wrote:
> >> Hi,
> >>
> >> Please review the backport of bug: "JDK-8158012: Use SW prefetch
> >> instructions instead of BIS for allocation prefetches on SPARC Core
> >> C4" to jdk8u-dev
> >>
> >> Please note that this is not a clean backport due to conflict in
> comments and slight re-order of code.
> >>
> >>
> >> Webrev:
> http://cr.openjdk.java.net/~shshahma/Muthu/8158012/webrev.00/
> >> jdk9 bug: https://bugs.openjdk.java.net/browse/JDK-8158012
> >> Original patch pushed to jdk9:
> >> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/eebdc7acebd4
> >>
> >> Test:  Ran jprt and jtreg.
> >>
> >> Regards,
> >> Muthusamy C
> >>