RFR: 8255351: Add detection for Graviton 1 & 2 CPUs

[Vladimir Kozlov]

On Mon, 23 Nov 2020 22:06:39 GMT, Evgeny Astigeevich <github.com+42899633+eastig at openjdk.org> wrote:

>> src/hotspot/cpu/aarch64/vm_version_aarch64.cpp line 169:
>> 
>>> 167:   if (_cpu == CPU_ARM && (_model == 0xd08 || _model2 == 0xd08)) {
>>> 168:     if (FLAG_IS_DEFAULT(UseSIMDForMemoryOps)) {
>>> 169:       FLAG_SET_DEFAULT(UseSIMDForMemoryOps, true);
>> 
>> What about A73? Should this flag be true for it too?
>
> Hi Vladimir,
> Thank you for reviewing the changes.
> Yes, it can be enabled. However I found only HiKey960/970 by Linaro use A73. Other devices are phones.
> I can do this if Linaro engineers agree.

ARM ecosystem is really strange :)
In this case keep these changes as it is and let Linaro engineers add it later if they want.

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PR: https://git.openjdk.java.net/jdk/pull/1315