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

[Ashutosh Mehra]

On Thu, 12 Sep 2024 17:09:50 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> Andrew Dinn has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   only check UseCompatibleCompressedOops on 64 bit builds
>
> src/hotspot/cpu/aarch64/aarch64.ad line 5175:
> 
>> 5173: operand indirectN(iRegN reg)
>> 5174: %{
>> 5175:   predicate(CompressedOops::shift() == 0 && !SCCache::is_on_for_write());
> 
> Does it imply that with SCC is on_write we will not have the shift == 0?

No, this is to prevent the match when compiling AOT code. We don't want to generate any AOT code which depends on shift == 0 as it may change during runtime.

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PR Review Comment: https://git.openjdk.org/leyden/pull/20#discussion_r1757538416