RFR(S) JDK-8206140 [lworld] Move return value null checks into the callee

[Tobias Hartmann]

Hi Ioi,

thanks for making these changes!

Your latest version of the patch looks good to me but I think we should hold off with pushing until
we know how to fix JDK-8207219 and fully understand if value attribute consistency checking is
strong enough to enable this optimization in all cases.

Thanks,
Tobias

On 12.07.2018 21:19, Ioi Lam wrote:
> I've simplified the runtime part of this patch after Harold pushed the "Add value types consistency
> checks" changes.
> 
> http://cr.openjdk.java.net/~iklam/valhalla/8206140_lworld_null_check_in_callee.v04/
> 
> Now Method::is_returning_vt() is initialized during class preparation time, and the run-time checks
> in the interpreter is kept to a minimum.
> 
> There's no change to the compiler part of the patch since the last webrev.
> 
> The test cases have been simplified since I no longer need to test for value types consistency.
> 
> Thanks
> 
> - Ioi
> 
> 
> 
> On 7/10/18 8:59 AM, Ioi Lam wrote:
>> Oops, will do :-)
>>
>> Thanks
>>
>> - Ioi
>>
>>
>> On 7/10/18 8:47 AM, Tobias Hartmann wrote:
>>> Hi Ioi,
>>>
>>> On 10.07.2018 17:33, Ioi Lam wrote:
>>>> http://cr.openjdk.java.net/~iklam/valhalla/8206140_lworld_null_check_in_callee.v03/
>>> Looks good to me but I think you need to add the copyright headers to the .jasm files (no new webrev
>>> required).
>>>
>>> Thanks,
>>> Tobias
>>
>