RFR: Load coops base shift from AOTRuntimeConstants in AOT code [v2]

[Vladimir Kozlov]

On Wed, 11 Sep 2024 14:45:58 GMT, Andrew Dinn <adinn at openjdk.org> wrote:

>> This PR modifies AOT compiled method code to load compressed oops base and shift constants via the AOTRuntimeConstants area rather than encode them as immediates. It also unlatches the currently forced setting of UseCompatibleCompressedOops, allowing the heap to be allocated wherever it will fit.
>
> Andrew Dinn has updated the pull request incrementally with one additional commit since the last revision:
> 
>   only check UseCompatibleCompressedOops on 64 bit builds

Thinking more.

On other hand, only AOT code will suffer. Recompiled code will be optimal which is good for peak performance.
And with UseCompatibleCompressedOops recompiled code will also suffer.

I need to see numbers how it affect performance of AOT code.  I hope CPU's prefetcher will keep these values nearby.

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PR Comment: https://git.openjdk.org/leyden/pull/20#issuecomment-2347393402