[aarch64-port-dev ] RFR (XXL): 8223347: Integration of Vector API (Incubator): AArch64 backend changes

[Yang Zhang]

> But to my earlier question. please: can the new instructions be moved into jdk head first, and then merged into the Panama branch, or not?

The new instructions can be classified as:
1. Instructions that can be matched with NEON instructions directly.
MulVB and SqrtVF have been merged into jdk master already. The patch of AbsV is in review [1].

2. Instructions that Jdk master has middle end support for, but they cannot be matched with NEON instructions directly.
Such as AddReductionVL, MulReductionVL, And/Or/XorReductionV
These new instructions can be moved into jdk master first, but for auto-vectorization, the performance might not get improved.
May I have a new patch for these? 

3. Panama/Vector API specific  instructions
Such as Load/StoreVector ( 16 bits), VectorReinterpret, VectorMaskCmp, MaxV/MinV, VectorBlend etc. 
These instructions cannot be moved into jdk master first because there isn't middle-end support.

Regards
Yang

[1] https://mail.openjdk.java.net/pipermail/aarch64-port-dev/2020-May/008861.html

-----Original Message-----
From: Andrew Haley <aph at redhat.com> 
Sent: Tuesday, May 26, 2020 4:25 PM
To: Yang Zhang <Yang.Zhang at arm.com>; Paul Sandoz <paul.sandoz at oracle.com>
Cc: hotspot-compiler-dev at openjdk.java.net; hotspot-dev at openjdk.java.net; core-libs-dev at openjdk.java.net; aarch64-port-dev at openjdk.java.net; nd <nd at arm.com>
Subject: Re: [aarch64-port-dev ] RFR (XXL): 8223347: Integration of Vector API (Incubator): AArch64 backend changes

On 25/05/2020 09:26, Yang Zhang wrote:
> In jdk master, what we need to do is that writing m4 file for existing 
> vector instructions and placed them to a new file aarch64_neon.ad.
> If no question, I will do it right away.

I'm not entirely sure that such a change is necessary now. In particular, reorganizing the existing vector instructions is IMO excessive, but I admit that it might be an improvement.

But to my earlier question. please: can the new instructions be moved into jdk head first, and then merged into the Panama branch, or not?
It'd help if this was possible.

--
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com> https://keybase.io/andrewhaley
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671