Loop strip mining to decreases safepoint poll frequency

[Aleksey Shipilev]

On 02/28/2017 02:41 PM, Roland Westrelin wrote:
> 
>> I would like to keep UseCLS to pretend to be "independent". E.g. UseCLS enables
>> safepoints in counted loops, and LSM>1 additionally strip mines the loops.
>> Regardless what the actual implementation is doing, the saner interface seems
>> better if done like that.
> 
> So what I suggested in my previous email is ok, right?

Yes. Looks like it. I'd probably forbid some combinations. For user settings,
this is the behavior I would expect:

 -UseCLS:         no safepoints, no mining
 -UseCLS LSM=0:   no safepoints, no mining
 -UseCLS LSM>=1:  illegal?
 +UseCLS:         safepoints + mining
 +UseCLS LSM=0:   illegal?
 +UseCLS LSM=1:   safepoints, but no mining
 +UseCLS LSM>=1:  safepoints + mining

-Aleksey