RFR(S): 8194740: Fix for: UseSubwordForMaxVector causes performance regression

[Vladimir Kozlov]

Hi Vivek,

Performance testing is finished and we see regressions.

SPECjvm2008-SOR.small with Parallel GC - 5-7% on all platfroms.
There is also 3-5% regression in MonteCarlo with G1 (we did not test 
with Praallel GC - it may also regress).

Please investigate it.

Thanks,
Vladimir

On 6/12/18 9:51 AM, Deshpande, Vivek R wrote:
> Hi Tobias
> 
> Thanks for testing it. I have changed the status to - In Progress.
> 
> Regards,
> Vivek
> 
> -----Original Message-----
> From: Tobias Hartmann [mailto:tobias.hartmann at oracle.com]
> Sent: Tuesday, June 12, 2018 2:48 AM
> To: Deshpande, Vivek R <vivek.r.deshpande at intel.com>; Vladimir Kozlov <vladimir.kozlov at oracle.com>; hotspot-compiler-dev at openjdk.java.net compiler <hotspot-compiler-dev at openjdk.java.net>
> Subject: Re: RFR(S): 8194740: Fix for: UseSubwordForMaxVector causes performance regression
> 
> Hi Vivek,
> 
> On 11.06.2018 20:51, Deshpande, Vivek R wrote:
>> http://cr.openjdk.java.net/~vdeshpande/SubwordFix/webrev.01/
> 
> This looks good to me as well. I've just submitted performance testing and premature results look great (+3.17% on SpecJVM2008 MPEG).
> 
> I'll let you know once the runs are completed. Please set the status of the bug to "In Progress".
> 
> Best regards,
> Tobias
>