RFR: JDK-8311035: CDS should not use dump time JVM narrow Klass encoding to pre-compute Klass ids [v8]

[Thomas Stuefe]

On Wed, 5 Jul 2023 14:44:35 GMT, Ashutosh Mehra <duke at openjdk.org> wrote:

>> Thomas Stuefe has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 12 commits:
>> 
>>  - Merge branch 'master' into fix-cleanup-CDS-nKlass-encoding
>>  - only build initializer functions for 64-bit
>>  - Consistently use runtime instead of future
>>  - Merge branch 'master' into fix-cleanup-CDS-nKlass-encoding
>>  - revert accidental change
>>  - Fix Windows build
>>  - Add alternative for !INCLUDE_CDS_JAVA_HEAP path
>>  - Merge branch 'master' into fix-cleanup-CDS-nKlass-encoding
>>  - fix comment
>>  - Merge
>>  - ... and 2 more: https://git.openjdk.org/jdk/compare/d6578bff...0ea2fa10
>
> src/hotspot/share/oops/compressedOops.cpp line 202:
> 
>> 200:   address encoding_range_end = requested_base + encoding_range_size;
>> 201: 
>> 202:   assert(requested_base <= addr && encoding_range_end >= end, "Encoding does not cover the full Klass range");
> 
> Is it possible for `requested_base` to ever be less than `addr`?

Not at the moment, no. Probably never. I separated those two mainly for cleanliness, since Klass range and encoding range are different things.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14688#discussion_r1253261336