RFR(S) 8075093: Enable UseFPUForSpilling support on SPARC

[Shrinivas Joshi]

Hi Dean,

Thanks for the review.

I only tried it on a micro-benchmark where a local variable in a tight 
loop was getting spilled to/filled from the stack. I noticed about 85% 
reduction in execution time.

-Shrinivas

On 9/2/2015 4:18 PM, Dean Long wrote:
> Looks fine.  Was there any measurable performance improvement?
>
> dl
>
> On 9/2/2015 12:51 PM, Vladimir Kozlov wrote:
>> https://bugs.openjdk.java.net/browse/JDK-8075093
>> http://cr.openjdk.java.net/~kvn/8075093/webrev
>>
>> SPARC S3 core and beyond have single-cycle MOV instructions (MOVdTOx, 
>> MOVxTOd) for FP-to-GP and GP-to-FP register moves. These when used 
>> under UseFPUForSpilling can help improve performance.
>>
>> Contributed-by: Shrinivas Joshi
>>
>> I reviewed changes.
>
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>