Review request for JDK-8037534

[Hannes Wallnoefer]

Won't CompilationEnvironment.getOptimisticType() widen vars that have 
not been assigned yet to object type (since their value is undefined)? 
If not, why not?

Other than that the patch looks good.

Hannes

Am 2014-03-24 15:12, schrieb Attila Szegedi:
> Repeated request to please review this. Since I got no reviews first time around, I updated it in-place with further development -- see the JIRA issue. box2d is down to 377 recompilations by having the compiler do safe evaluation of certain expressions.
>
> http://cr.openjdk.java.net/~attila/8037534/webrev.01/index.html
>
> On Mar 19, 2014, at 5:34 PM, Attila Szegedi <attila.szegedi at oracle.com> wrote:
>
>> Actually, the link is http://cr.openjdk.java.net/~attila/8037534/webrev.01/index.html
>>
>> On Mar 19, 2014, at 5:33 PM, Attila Szegedi <attila.szegedi at oracle.com> wrote:
>>
>>> Please review JDK-8037534 at http://cr.openjdk.java.net/~attila/8037534/webrev.00
>>>
>>>  From the JIRA issue:
>>>
>>> "When doing on-demand compilation, we can use the current runtime scope to look up types of variables in scope; if they're already wider than the current optimistic assumption, we can use that type and cut down on number of recompilation."
>>>
>>> This cuts down warmup time with optimistic compilation. In Octane tests, box2d now does 1300 deoptimizations instead of 1552 while it warms up, and earley-boyer is down to 1577 from whopping 3028.
>>>
>>> Thanks,
>>> Attila.