RFR(S): 8005079: fix LogCompilation for incremental inlining

[Roland Westrelin]

Hi Vladimir,

Thanks for taking another look.

> Need CICountOSR check, shift compile_id by 32 and use bit 31 to indicate OSR when needed (I doubt we get unique() with bit 31 set):
> 
>     jlong id = ((jlong)unique()) + ((jlong)compile_id())<<32 + (CICountOSR && is_osr_compilation() ? 1<<31 : 0);
> 
> Otherwise good.

Can you explain why this is better?
I don’t see why the test for CICountOSR is needed. Without the test for CICountOSR, the generated id is unique as well, whether CICountOSR is on or off.
The most important part is that the id be unique within a compilation otherwise the LogCompilation tool can be confused. I played it extra safe by keeping the lower part for unique() which is what makes the id unique within a compilation. Why put the compile id in its own 32 bit half? What problem does it solve?

Roland.


> 
> Thanks,
> Vladimir
> 
> On 3/25/14 7:00 AM, Roland Westrelin wrote:
>> Hi Vladimir,
>> 
>>>>> It is good.
>>>> 
>>>> Thanks for the review.
>>>> 
>>>>> One thing you may need to change is C->log_inline_id((jlong)this).
>>>>> Address is not good id when you look on log file and it could be the same between compilations.
>>>>> I think some combination of compile_id<<shift+(adjustment for OSR when CICountOSR=true)+(unique node number at time when cg was created or other sequential number).
>>>> 
>>>> I don’t understand why it matters. The id is only used within a single compilation by the LogCompilation tool to correctly match a call site at which we stopped inlining with a call site at which we start to inline again later on.
>>> 
>>> It will be confusing when you search in a log file for such id and it matches ids from other compilations.
>> 
>> I followed your suggestion:
>> http://cr.openjdk.java.net/~roland/8005079/webrev.04/
>> 
>> Roland.
>> 
>>> 
>>> Vladimir
>>> 
>>>> 
>>>> Roland.
>>>> 
>>>>> Thanks,
>>>>> vladimir
>>>>> 
>>>>> On 3/21/14 2:04 AM, Roland Westrelin wrote:
>>>>>>>> http://cr.openjdk.java.net/~roland/8005079/webrev.02/
>>>>>>> 
>>>>>>> In order for equals to be correct you have to do an instanceof check.
>>>>>> 
>>>>>> Ok.
>>>>>> 
>>>>>> http://cr.openjdk.java.net/~roland/8005079/webrev.03/
>>>>>> 
>>>>>> Roland.
>>>>>> 
>>>> 
>>