RFR: 8340012: [C2] assert(KlassEncodingMetaspaceMax > pd) failed: change encoding max if new encoding after 8338526 [v2]

[Thomas Stuefe]

On Fri, 13 Sep 2024 15:49:06 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> src/hotspot/share/oops/compressedKlass.inline.hpp line 54:
>> 
>>> 52:   assert(check_alignment(v), "Address not aligned");
>>> 53:   uint64_t pd = (uint64_t)(pointer_delta(v, narrow_base, 1));
>>> 54:   assert(KlassEncodingMetaspaceMax > pd, "change encoding max if new encoding (Klass " PTR_FORMAT ", Base " PTR_FORMAT ")", p2i(v), p2i(narrow_base));
>> 
>> Would it be possible to leave this hunk out? I am in the process of rewriting large parts of this for Lilliput, so it won't survive in this current form. These things will be a lot better tested, and the assertion messages make more sense, too)
>
> Thanks for taking a look! It would be possible to revert this part. But I don't understand the benefit. Wouldn't it be better to have this extra output for the time being? I don't know when Lilliput will make it to jdk head. It seems to be not targeted, yet.
> Or will your new code be ready soon and contributed separately?

Okay, sure, maybe you are right. Merging it should be easy enough.

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PR Review Comment: https://git.openjdk.org/jdk/pull/20971#discussion_r1759117593