RFR: 8277617: Optimize array copy and clear on x86_64

Tue Nov 23 02:48:09 UTC 2021

On Tue, 23 Nov 2021 02:14:46 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Currently 32-byte instructions are used for small array copy and clear. 
>> This can be optimized by using 64-byte instructions.
>> 
>> Please review.
>> 
>> Best Regards,
>> Sandhya
>
> Plus some performance numbers would be useful. Thanks

@dholmes-ora We see about 25% gain on a micro on our latest platform. There is no cpuid bit for this, so the closest was to check  for the new serialize ISA supported on this platform.

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PR: https://git.openjdk.java.net/jdk/pull/6512