On Tue, 10 Sep 2024 08:37:43 GMT, Roman Kennke <rken...@openjdk.org> wrote:
>>> could be any value that is not a valid field offset >> >> I understand that that "random value" needs to satisfy this condition. > > With compact headers, this value should only be used in C2, and not really as > an actual offset. An earlier version of the change had the value in > src/hotspot/share/opto/type.hpp instead, and only an assert(!UCOH) in > oopDesc::klass_offset_in_bytes(). I think this would be a better solution > overall, because it prevents accidental (and wrong) usage of the klass_offset > in the runtime. Back then it has been rejected by somebody (don't remember), > because it made the C2 diff a little messier, so I kept it like it is now. I > would prefer to reinstate it, though. > (Fwiw, the method is also used during Universe initialization). Yes, but only in the -UCOH branch. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20677#discussion_r1751604467
