RFR 8078563 - add profitability tests for reductions

[Vladimir Kozlov]

Testing shows no problems so I will push it.

Thanks,
Vladimir

On 4/29/15 2:47 PM, Vladimir Kozlov wrote:
> I want to test it with my and your tests when I have time.
>
> Thanks,
> Vladimir
>
> On 4/29/15 2:38 PM, Berg, Michael C wrote:
>> Vladimir, does this patch also look ok to you as well?
>>
>> I believe you have reviewed the changes.
>>
>> Thanks,
>>
>> Michael
>>
>> *From:*Christian Thalinger [mailto:christian.thalinger at oracle.com]
>> *Sent:* Wednesday, April 29, 2015 10:27 AM
>> *To:* Berg, Michael C
>> *Cc:* hotspot-compiler-dev at openjdk.java.net
>> *Subject:* Re: RFR 8078563 - add profitability tests for reductions
>>
>> I think this looks good but as I said I’m not an expert in this area.
>>   It would be good to have an additional reviewer.
>>
>>     On Apr 29, 2015, at 10:23 AM, Berg, Michael C
>>     <michael.c.berg at intel.com <mailto:michael.c.berg at intel.com>> wrote:
>>
>>     Christian, do you have any additional comments or does the code
>> look ok?
>>
>>     Thanks,
>>
>>     Michael
>>
>>     *From:*Christian Thalinger [mailto:christian.thalinger at oracle.com]
>>     *Sent:* Monday, April 27, 2015 9:49 AM
>>     *To:* Berg, Michael C
>>     *Cc:* hotspot-compiler-dev at openjdk.java.net
>>     <mailto:hotspot-compiler-dev at openjdk.java.net>
>>     *Subject:* Re: RFR 8078563 - add profitability tests for reductions
>>
>>     *+       // Length 2 reductions of INT/LONG do not offer
>> performance benefits*
>>
>>     *+       if (((arith_type->basic_type() == T_INT) ||
>> (arith_type->basic_type() == T_LONG)) && (size == 2)) {*
>>
>>     I don’t know that code very well but can there be reductions with
>>     size == 1?
>>
>>         On Apr 23, 2015, at 5:53 PM, Berg, Michael C
>>         <michael.c.berg at intel.com <mailto:michael.c.berg at intel.com>>
>> wrote:
>>
>>         Hi Folks,
>>
>>         We (Intel) would like to add profitability tests to superword to
>>         gate scenarios where reduction optimization overhead is roughly
>>         equal to the benefit gained by vectorization.
>>
>>         We would like to do this for all x86 enabled microarchitectures
>>         that support reductions and superword.  This new constraint was
>>         tested on SSE and AVX (1,2) enabled platforms.
>>         The contribution as referenced by RFR 8078563 is defined by the
>>         information at the links below.
>>
>>         Please review this bug entry and its code and comment as needed:
>>
>>         https://bugs.openjdk.java.net/browse/JDK-8078563
>>
>>         And its code and test addition (this is a small patch):
>>
>>         http://cr.openjdk.java.net/~kvn/8078563/webrev/
>>
>>
>>
>>         Vladimir Koslov has offered to sponsor this patch.
>>
>>         Thanks,
>>
>>         Michael
>>