RFR(M): 8200303: C2 should leverage profiling for lookupswitch/tableswitch

[Vladimir Kozlov]

On 4/5/18 5:02 AM, Tobias Hartmann wrote:
> Hi Roland,
> 
> On 05.04.2018 11:54, Roland Westrelin wrote:
>> http://cr.openjdk.java.net/~roland/8200303/webrev.02/
> 
> Looks good to me. So far, testing looks good as well.

+1

Roland, did you perform any performance testing?

> 
>> I fixed the typo and added MachJump to vmstructs.
>>
>> I don't understand how the MachIfNode class in the SA is supposed to be
>> used. I tried dumping a graph that has a MachIfNode from clhsdb and the
>> MachIfNode shows up as unknown:
>>
>>   7      UnknownNode<0x00007fe79787c428> ===  9  8    [[ 6  28 ]]
>>   28     IfFalse ===  7  [[ 27 ]]
>>
>> So I'm not sure it's worth the trouble of adding a MachJumpNode.
> I agree. If so, we should fix this altogether (i.e. for existing nodes as well) but I'm not sure if
> anyone is using graph dumping via the SA.

I think we should fix it - it is good starter task for community. 
Please, file a bug.

Thanks,
Vladimir

> 
> Best regards,
> Tobias
>