RFR: 8192123: Zero should use compiler built-ins for atomics on linux-arm

[coleen.phillimore at oracle.com]

On 11/29/17 10:04 AM, Andrew Haley wrote:
> On 29/11/17 14:08, John Paul Adrian Glaubitz wrote:
>> Since the compiler built-ins for cmpxchg() work exactly like the current ARM-specific
>> implementation in Zero, there is no need anymore to carry our own implementation but
>> rather rely on gcc which helps simplifying the code.
>>
>> I have successfully tested this change in the following targets:
>>
>> - Linux ARMv4T
>> - Linux ARMv7
>>
>> My change also removes a single empty line to make the formatting more
>> consistent. Hope this is ok.
> Hmm.  This doesn't fix a bug, and there's a non-zero probability of
> introducing one.  I guess it should be OK, but this is a combination
> of performance improvement (possibly) and cleanup.
>
Please save this change for JDK 11.
Thanks,
Coleen