RFR 8078563 - add profitability tests for reductions

[Christian Thalinger]

+       // 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> 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 <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/ <http://cr.openjdk.java.net/~kvn/8078563/webrev/>
> 
> 
> Vladimir Koslov has offered to sponsor this patch.
>  
> Thanks,
> Michael

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