Request for review: JDK-715889: Non-zero padding is still not allowed in the tableswitch/lookupswitch instructions

[harold seigel]

Hi Vladimir,

Thanks for your comments.

I'll take a look at that code, but it needs to work with relaxed padding 
in order to be JVM spec compliant.

Harold

On 2/21/2013 6:18 PM, Vladimir Kozlov wrote:
> Harold,
>
> What about code in runtime/relocator.cpp ? Also 
> TemplateTable::*switch() in templateTable_<arch>.?pp and other places 
> where we process switches? Will they work if we relax padding?
>
> Thanks,
> Vladimir
>
> On 2/21/13 12:25 PM, harold seigel wrote:
>> Hi,
>>
>> Please review the following change to fix bug 7154889.
>>
>> Summary:
>> The JVM spec was changed to allow nonzero padding bytes for
>> lookupswitch/tableswitch bytecodes.  This fix implements this change by
>> suppressing the check for non-zero padding bytecodes for classfile
>> versions 51 and higher.  This fix is implemented in both verifiers.
>> Hence, there are two webrevs.
>>
>> The fix was tested with the JCK vm and lang tests and with a test that
>> had nonzero padding bytes in classes with classfile versions 50, 51, and
>> 52.
>>
>> Open webrevs at:
>> http://cr.openjdk.java.net/~hseigel/bug_7154889_split_vfr/
>> <http://cr.openjdk.java.net/%7Ehseigel/bug_7154889_split_vfr/>
>> http://cr.openjdk.java.net/~hseigel/bug_7154889_old_vfr/
>> <http://cr.openjdk.java.net/%7Ehseigel/bug_7154889_old_vfr/>
>>
>> Bug link at http://bugs.sun.com/view_bug.do?bug_id=7154889
>>
>> Thanks!  Harold