RFR: 8253049: Enhance itable_stub for AArch64 and x86_64

[Andrew Haley]

On 15/09/2020 10:02, Vladimir Ivanov wrote:
> And speaking of the overall approach (as it is implemented now), IMO 
> increased complexity doesn't worth it. If interface calls become a 
> bottleneck, the problem lies not in itable stub, but the overall design 
> which requires linear scan over itables. It's better to put the effort 
> there than micro-optimizing the stub.

Indeed. When I first came to HotSpot after working on GCJ for years
I was very surprised to see a linear scan used for interface dispatch.

The code improvements look to be fairly minor.

-- 
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