RFR: several small changes including 8207040: [lworld] TestLWorld fails with "Meet Not Symmetric" with -Xcomp

[Tobias Hartmann]

Hi Roland,

okay, thanks for the clarifications. Looks good to me!

Tobias

On 16.07.2018 09:53, Roland Westrelin wrote:
> 
>>> http://cr.openjdk.java.net/~roland/8207040/webrev.00/
>>
>> Looks good to me.
> 
> Thanks for the review.
> 
>>> - checkcast buffers values when it's not needed. The change delays
>>>   allocation. I actually wonder if the path where we allocate is seen in
>>>   practice and if it is if we need to allocate at all.
>>
>> Did you try to add an assert and check if it's triggered with our test?
> 
> I tried it. That code path is executed at parse time.
> 
>>> - the Parse::merge_common sometimes buffers a value when there's no
>>>   merge point which is unnecessary so I changed that logic too.
>>
>> Looks like the checks you are added are the ones used further below (line 1767) but without the
>> control()->is_Region() check. Do you know why it's not needed?
> 
> I'm not sure but from the comment it doesn't seem to be part of the
> logic that detects multiple predecessors.
> 
>> Please run all compiler tests with and without -XX:CompileTreshold=100 before pushing.
> 
> Tests pass except for TestNewAcmp.java that fails with
> InvocationTargetException but that's a known issue.
> 
> Roland.
>