AARCH64: 8064611: Changes to HotSpot shared code

[Andrew Haley]

On 11/19/2014 03:45 AM, Dean Long wrote:
> On 11/18/2014 7:03 PM, Vladimir Kozlov wrote:
>> Yes, we can hide AARCH64 using something similar to 
>> CODE_CACHE_SIZE_LIMIT macro which could be overwritten in platform 
>> specific files if needed: USE_STORE_RELEASE_FOR_VOLATILE.
>> Or slightly more complicated declaration similar to 
>> support_IRIW_for_not_multiple_copy_atomic_cpu boolean constant.
>>
>> Dean, will it help us if we do that? If yes, then we should do that.
>>
> Yes, this will help us.  Following the boolean constant example, we 
> would have something like:
> 
> #ifdef USE_STORE_RELEASE_FOR_VOLATILE
> const bool use_store_release_for_volatile = true;
> #else
> const bool use_store_release_for_volatile = false;
> #endif

The problem with this is that the AArch64 stlr instruction isn't
esactly store release, so is this #define rather misleading.  Other
processors have store release instructions, but none of them do quite
what the AArch64 does.

But really I just want this patch to move forward, so I'll agree to
anything which is not ridiculous.

Andrew.