Request for review: 7132690 InstanceKlass:_reference_type should be u1 type

Vitaly Davidovich vitalyd at
Tue Jan 24 14:13:48 PST 2012

Hi Jiangli,

This is probably overly paranoid so feel free to ignore, but should the
setter in InstanceKlass assert that the passed in ReferenceType fits into a
u1 instead of silently narrowing it? Or change the setter to take a u1 and
make caller do the cast? This would prevent someone defining another member
of the enum with an explicit value that doesn't fit into u1.  Like I said,
paranoia ... :)


Sent from my phone
On Jan 24, 2012 3:06 PM, "Jiangli Zhou" <jiangli.zhou at> wrote:

> Hi,
> Please review the change for 7132690:
> It changes InstanceKlass::_reference_type from ReferenceType to u1. The
> ReferenceType is defined as an enum with 6 values (src/share/vm/utilities/
> **globalDefinitions.hpp). The change saves 4-byte for each class.
> Tested with runThese and ute vm.quick.testlist. Ran jprt.
> Thanks,
> Jiangli
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