RFR(S): 8231291: C2: loop opts before EA should maximally unroll loops

[Vladimir Kozlov]

Looks good.

Thanks,
Vladimir K

On 12/20/19 8:48 AM, Roland Westrelin wrote:
> 
> Thanks for reviewing this, Vladimir.
> 
>> cfgnode.cpp - should we also check for is_top() to set `doit = false` and bailout?
> 
> This:
> 
> http://cr.openjdk.java.net/~roland/8231291/webrev.02/
> 
>> Why you added check in must_be_not_null()? It is used only in library_call.cpp and should not relate to this changes.
>> Did you find some issues?
> 
> I hit a crash when doing some CTW testing because an argument to
> must_be_not_null() was already known to be not null. I suppose it's
> unrelated to that change and something changed in the libraries instead.
> 
> Roland.
>