[master] RFR: 8301562: [Lilliput] Runtime flag to enable Lilliput

[Aleksey Shipilev]

On Thu, 2 Feb 2023 13:04:27 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

> This change introduces an experimental runtime flag -XX:[+/-]UseCompactObjectHeaders which can be used to disable Lilliput. The flag guards all the relevant places that directly affect the object layout and the accesses to Klass* etc. The change also restores the previous behaviour when -UseCompactObjectHeaders is selected.
> 
> Testing:
>  - [x] tier1 (x86_64, x86_32, aarch64) +UseCompactObjectHeaders
>  - [x] tier2 (x86_64, x86_32, aarch64) +UseCompactObjectHeaders
>  - [x] tier1 (x86_64, x86_32, aarch64) -UseCompactObjectHeaders
>  - [x] tier2 (x86_64, x86_32, aarch64) -UseCompactObjectHeaders

I can take a look at x86_32 stuff, if you need it.

-------------

PR: https://git.openjdk.org/lilliput/pull/70