review (S) for 6982537: Crash in Node*step_through_mergemem

[Tom Rodriguez]

On Sep 22, 2010, at 10:59 AM, Vladimir Kozlov wrote:

> Thank you, Tom, for fixing this.
> 
> Few notes.
> In escape.cpp TypeInstPtr was not renamed in the comment.
> Also check for "memcpy" is not related to this changes.

That was a mistake during transplantation.  Fixed.

tom

> 
> Thanks,
> Vladimir
> 
> 
> Tom Rodriguez wrote:
>> http://cr.openjdk.java.net/~never/6982537
>> 6982537: Crash in Node*step_through_mergemem
>> Reviewed-by:
>> Code which was examining the type of memory was attempting to
>> introspect on the klass of TypeOopPtr but wasn't checking for NULL
>> which led to crashes when it looked at a primitive array type.  The
>> fix is to check for NULL.  I also updated similar code in escape.cpp
>> and corrected variable names to match the types.  Tested with failing
>> test from bug report.
>> src/share/vm/opto/memnode.cpp
>> src/share/vm/opto/escape.cpp