Request for reviews (S): 7071709: JSR 292: switchpoint invalidation should be pushed not pulled

[Tom Rodriguez]

On Aug 25, 2011, at 10:51 AM, Rémi Forax wrote:

> On 08/25/2011 06:55 PM, Tom Rodriguez wrote:
>> Why is this being done for VolatileCallSite?  There's no mechanism for falling back if the field is invalided too many times so we're just going to recompile over and over again which seems wrong.  Otherwise it looks ok.
> 
> Maybe because it can be invalidated only once from the API side.

The docs for VolatileCallSite suggest setTarget can be called whenever you feel like it, so it seems like it can be set many times.  MutableCallSite can be as well but the implication is that it's not updated very often.  I'm actually unclear what distinction is trying to be made with VolatileCallSite.

tom

> 
>> 
>> tom
> 
> Rémi
> 
>> 
>> On Aug 25, 2011, at 6:54 AM, Christian Thalinger wrote:
>> 
>>> http://cr.openjdk.java.net/~twisti/7071709/
>>> 
>>> 7071709: JSR 292: switchpoint invalidation should be pushed not pulled
>>> Reviewed-by:
>>> 
>>> SwitchPoints use a MutableCallSite for its implementation.  The fix is
>>> to treat the target field of constant CallSites as a compile time
>>> constant and add a dependence for invalidation of the optimization.
>>> 
>>> src/share/vm/opto/memnode.cpp
>>> src/share/vm/opto/parse3.cpp
>>> 
>