Request for review: 7102776 Pack instanceKlass boolean fields into single u1 field

[Dean Long]

OK thanks.

dl

On 11/14/2011 10:50 AM, Tom Rodriguez wrote:
> I don't know that there's a specific test which would have caught this.  The purpose of the flag is minimize the time spent searching around in the class hierarchy when rechecking dependencies.  Mostly it would have resulted in spending a little more time checking but I can't say for sure that it would  have been noticed.
>
> tom
>
> On Nov 14, 2011, at 10:33 AM, Dean Long wrote:
>
>> By the way, is there a test that would have caught that "set" was being called instead of "clear"?
>>
>> dl
>>
>> On 11/14/2011 10:20 AM, Jiangli Zhou wrote:
>>> Hi Bob,
>>>
>>> Sorry for the delay. Here is the updated webrev with dependencies.cpp fixed: http://cr.openjdk.java.net/~bobv/7102776/webrev.01/. Thanks for catching that!
>>>
>>> Thanks,
>>> Jiangli
>>>
>>>
>>> On 11/09/2011 02:13 PM, Bob Vandette wrote:
>>>> Jiangli,
>>>>
>>>> src/share/vm/code/dependencies.cpp:1636     instanceKlass::cast(d)->set_is_marked_dependent();
>>>>
>>>> Isn't this supposed to be clear_is_marked_dependent()?
>>>>
>>>> Bob.
>>>>
>>>>
>>>> On Nov 9, 2011, at 12:47 PM, Jiangli Zhou wrote:
>>>>
>>>>> Compact following 4 instanceKlass boolean fields into a signal u1 field. Each flag now uses 1-bit. The new field is placed after the _idnum_allocated_count field to utilize the unused 2-byte after _idnum_allocated_count. Compacting these fields saves 4-bytes for each loaded classes.
>>>>>
>>>>>   bool _is_marked_dependent; // used for marking during flushing and
>>>>>   deoptimization
>>>>>   bool _rewritten; // methods rewritten.
>>>>>   bool _has_nonstatic_fields; // for sizing with UseCompressedOops
>>>>>   bool _should_verify_class; // allow caching of preverification
>>>>>
>>>>> http://cr.openjdk.java.net/~bobv/7102776/webrev.00/
>>>>>
>>>>> Tested with runThese on ubuntu. Ran JPRT.
>>>>>
>>>>> Thanks,
>>>>> Jiangli