RFR: 8267356: AArch64: Vector API SVE codegen support

[Ningsheng Jian]

Hi Paul,

Thanks for the clarification about JEP process.

On 5/21/21 6:30 AM, Paul Sandoz wrote:
> Hi Ningsheng,
> 
> Thank you for doing this work and preparing a review.
> 
> We might have our wires crossed a little with regards to JEPs, or we just need to clarify the intent.
> 
> I think this important work needs to be part of a Vector API JEP, it being a relevant new feature (in this case with a large contribution of code). That approach has been applied to the SVML support on x86 which is currently part of JEP 414, in addition to the API enhancements. I don’t think we can skip the JEP process for such a feature, and especially so since this is an incubating feature.
> 
> The reason I did not included SVE support in JEP 414, as we discussed, was because it may be too late to get the code properly reviewed in time by 17 RDP 1 (feature freeze on 2021/06/10).
> (Note that JEP 414 currently explicitly calls out SVE support as future work.)
> 
> It's not that the JEP process takes time, it's that code reviews can take time, especially closer to RDP 1 as reviewers are often very busy.
> 
> If you and the reviewers think the code can be reviewed by 17 RDP 1 then we can update JEP 414 and include it. But, I strongly recommend we should include it in a further JEP we can plan and propose to target for 18 (I can prepare a new draft JEP after JEP 414 integrates).
> 

Agree that this SVE support feature needs to be included in Vector API 
JEP. I am not familiar with the JEP process, but it seems to me that 
updating JEP 414 at the last minute is risky. So, I am happy to defer 
the integration until 18, with another Vector API JEP.

> However, to be clear, that does not negate starting the code review process now as you have done, in fact that’s a good thing :-) being prepared for a proposed release early in that release cycle reduces risk and increases chances of integration.
> 

Yes, review comments for this patch are welcome. :-) I have set the "Fix 
Version" to 18 in JBS.

Thanks,
Ningsheng