Request for reviews (S): 7050280: assert(u->as_Unlock()->is_eliminated()) failed: sanity

[Igor Veresov]

This seems ok.

igor

On 6/2/11 7:25 PM, Vladimir Kozlov wrote:
> http://cr.openjdk.java.net/~kvn/7050280/webrev
>
> Fixed 7050280: assert(u->as_Unlock()->is_eliminated()) failed: sanity
>
> Marking locks for elimination is done in IGVN. Unfortunately the order
> of IGVN worklist processing may affect this marking. Also during EA obj
> may point to several objects but after few ideal graph transformations
> (CCP) it may point to only one non escaping object (but still using
> phi), corresponding locks and unlocks will be marked for elimination.
> Later obj could be replaced with a new node (new phi) and will be no
> escape information about it. And later after some graph reshape other
> locks and unlocks (which were not marked for elimination before) are
> connected to this new obj but they still will not be marked for
> elimination since new obj has no escape information.
>
> Fix:
> Do first round of locks marking during EA after ConnectionGraph is
> constructed when all nodes have escape information. During Macro nodes
> expansion move creation of new eliminated BoxLock into new separate
> method which is called before locks elimination. Use this method to mark
> all associated (same box and obj) lock and unlock nodes which were not
> marked before (instead of the assert).
>
> Tested with failing case and full CTW.