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

[Vladimir Kozlov]

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.

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