On Thu, 12 Sep 2024 15:42:59 GMT, Thomas Stuefe <stu...@openjdk.org> wrote:
>> src/hotspot/share/opto/machnode.cpp line 390:
>>
>>> 388: t = t->make_ptr();
>>> 389: }
>>> 390: if (t->isa_narrowklass() && CompressedKlassPointers::shift() == 0) {
>>
>> Does this change have any effect? `UseCompressedClassPointers` should be
>> implied by `t->isa_narrowklass()`.
>
> I don't remember if this change was a reaction to an error or if I just
> guarded `CompressedKlassPointers::shift()` with +UseCCP because that is the
> prerequisite now. Probably the latter. I can remove this. Probably should
> assert then for +UseCCP.
@tstuefe @rkennke what do you think about this suggestion? If there is a known
case where `t->isa_narrowklass() && !UseCompressedClassPointers` holds, it
should be investigated because it might be a symptom of a larger problem. If
there is no such a case, I think the explicit `UseCompressedClassPointers` test
should be removed to avoid confusion.
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PR Review Comment: https://git.openjdk.org/jdk/pull/20677#discussion_r1778724120
