review for 7121073: secondary_super_cache memory slice has incorrect bounds in flatten_alias_type

[Vladimir Kozlov]

Good.

Thanks,
Vladimir

Tom Rodriguez wrote:
> On Dec 15, 2011, at 12:44 PM, Vladimir Kozlov wrote:
> 
>> Tom,
>>
>> Can you updated related comments? Otherwise looks good.
> 
> How about this:
> 
>     // If we are referencing a field within a Klass, we need
>     // to assume the worst case of an Object.  Both exact and
>     // inexact types must flatten to the same alias class so
>     // use NotNull as the PTR.
> 
> tom
> 
>> Thanks,
>> Vladimir
>>
>> Tom Rodriguez wrote:
>>> http://cr.openjdk.java.net/~never/7121073
>>> 7 lines changed: 2 ins; 0 del; 5 mod; 3239 unchg
>>> 7121073: secondary_super_cache memory slice has incorrect bounds in flatten_alias_type
>>> Reviewed-by:
>>> To ensure that memory operations for type checks are properly ordered,
>>> several fields are smeared together into the same alias slice.  The
>>> existing logic is sloppy and includes a slightly larger chunk of
>>> memory than intended.  Currently this is fine but changes to the shape
>>> of Klass can invalidate it.  The fix is to properly test the
>>> boundaries.  Additionally I changed the logic for setting the PTR to
>>> use NotNull instead of Constant to be consisten with all the following
>>> logic which uses NotNull.  Tested with full CTW.
>