review (M) for 6892658: C2 should optimize some stringbuilder patterns

[Vladimir Kozlov]

Tom Rodriguez wrote:
>> You use fetch_static_field() only to read Integer.sizeTable. Does it need
>> to be so generalized? But you can keep it as it is.
> 
> Originally I was going to read some other fields so I needed something general.  It's based on do_get_xxx and I don't see any reason to simplify it.  I could move it over into GraphKit.
> 

OK.

>> In int_stringSize(), I think, TypeAryPtr::INTS memory should be used instead of
>> TypeAryPtr::CHARS (for final_mem) and int_adr_idx (needs to add it) instead
>> of char_adr_idx.
> 
> Actually there are no stores so it's not needed at all.  I'd added some debugging code that did a runtime call and needed the phi but I think I can remove it completely now.
> 

OK.

>> Why 6 is limit for constant strings? Add some comments.
> 
> Ok. It's just a number.  6 seems like an ok code space vs. speed tradeoff.

May be we should have it as flag or definition to be more visible?

Thanks,
Vladimir

> 
> tom
> 
>>
>> Vladimir
>>
>> Tom Rodriguez wrote:
>>> http://cr.openjdk.java.net/~never/6892658/
>