Request for reviews (M): 7105605: Use EA info to optimize pointers compare

[Tom Rodriguez]

I like the renaming you did in optimize_ptr_compare.  This comment:

+   // Check if one set has only not escaping allocations.

seems like it needs more detail explaining why that's important.  I presume it's because if they are all non-escaping then they must be disjoint from the other set.  Is that right?  Does the _scalar_replaceable flag change any of this?  I thought if that was false then we might lose track of the identity of the object.

How effective is this at eliminating compares?  Is it useful even if there aren't non-escaping object?

tom

On Nov 8, 2011, at 8:27 PM, Vladimir Kozlov wrote:

> http://cr.openjdk.java.net/~kvn/7105605/webrev
> 
> 7105605: Use EA info to optimize pointers compare
> 
> EA Connection Graph can help to optimize pointers compare for non escaping allocations.
> 
> Tested with CTW, jtreg, NSK, refworkload.
> 
> Thanks,
> Vladimir