On Thu, 12 Sep 2024 15:42:59 GMT, Thomas Stuefe <[email protected]> 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.
I see, thanks. In that case, I would suggest removing the explicit
`UseCompressedClassPointers` test, since it should be implied by
`t->isa_narrowklass()`. `check_init()` within
`CompressedKlassPointers::shift()` would already fail for the unexpected case
where `t->isa_narrowklass() && !UseCompressedClassPointers`, no?
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/20677#discussion_r1758270661
