RFR(L) Valhalla support for AArch64 v.05

[Dmitry Samersoff]

Hi Ioi,

On 27.06.2019 22:00, Ioi Lam wrote:
> I’ll take a stab at refactoring the packing/unpacking code and will send out an RFR so you can check if it’s useful for you.

Thank you!

> I agree that a tag that marks the CRs that have platform specific code would be useful. Many of my changes have both a shared part and an x86 part, and it may not be easy to split them into separate changesets.

There is no need to split shared and platform specific parts. What I'm
looking for is an easy way to monitor changesets that require my
attention on CR level.

> Another way maybe to search the changes that have cpu/ in the list of files changed.

This is exactly what I am doing today, and this does not always help
because of upstream mergers.

-Dmitry

> 
>> On Jun 27, 2019, at 9:34 AM, Dmitry Samersoff <dms at samersoff.net> wrote:
>>
>> Ioi,
>>
>> I agree with you about value type pack/unpack logic.
>>
>> I'm not sure that it's possible to put it to shared code completely, but
>> at least we can consider moving the entire pack/unpack logic into a
>> separate function and re-use it rather than duplicate code.
>>
>>
>> Anther (not-technical) thing, that simplify porting is mark CR, which
>> touches platform-specific code, with some specific label.
>>
>> -Dmitry
>>
>>
>> Another (process) thing that can simplify porting is the CR tag, which
>> concerns the platform-specific code, a specific label.
>>
>>> On 27.06.19 19:09, Ioi Lam wrote:
>>> Hi Dmitry,
>>>
>>> During the port, have you found anything that should be refactored and
>>> put into shared code?
>>>
>>> One thing that I am thinking of doing is to refactor the code in
>>> macroAssembler_x86.cpp that deals with ValueTypePassFieldsAsArgs.
>>> Hopefully that will make the port to other architectures easier.
>>>
>>> Thanks
>>> - Ioi
>>>
>>>
>>>> On 6/27/19 12:43 AM, Dmitry Samersoff wrote:
>>>> Hello Everybody,
>>>>
>>>>
>>>> Please review v.05 of adding AArch64 support to lworld branch
>>>>
>>>> http://cr.openjdk.java.net/~dsamersoff/valhalla_lworld_aarch64/webrev.05/
>>>>
>>>> What was done:
>>>>
>>>>    Implemented Valhalla support for aarch64.
>>>>
>>>>    Support for ValueTypePassFieldsAsArgs and ValueTypeReturnedAsFields
>>>>    is not completed and is not included into this webrev
>>>>    to reduce review and rebasing efforts.
>>>>
>>>> Testing:
>>>>
>>>>     All tests in runtime/valhalla/valuetypes and in
>>>> compiler/valhalla/valuetypes/ are passed
>>>>
>>>>     compiler/valhalla/valuetypes/TestMethodHandles.java
>>>>     compiler/valhalla/valuetypes/TestBasicFunctionality.java
>>>>
>>>>     are passed after manually tweaking of output patterns, I have not
>>>> found a way to support both x86 and aarch64, so these tests remain
>>>> unchanged and run on x64 only.
>>>>
>>>>
>>>> -Dmitry
>>>
>