On 03/21/2013 08:31 PM, Krystal Mo wrote:
> Hi Jochen,
>
> At least with the current tip version of HotSpot, the
> mh.invokeWithArguments() callsite is not likely to get its actual target
> inlined into the caller; we depended a lot on being able to prove that
> the MethodHandle is a (JIT-)compiled-time constant to be able to do
> inlining across the MethodHandle.invoke/invokeExact boundary.
>
> I'm working on adding profiling support for
> MethodHandle.invoke/invokeExact (which invokeWithArguments() will call),
> and it looks at what MethodHandles get passed in.
> When that work lands in HotSpot, your example will be a source of
> profile pollution just like the well-known megamorphic callsites in the
> old days, so I wouldn't suggest doing that.
I suppose you take a look to the instances.
You can do something similar actually by using invokedynamic +
a guardWithTest that checks already seen instances instead of doing a
plain mh.invoke*
I think Duncan and Georges do something like that in Magik.
>
> More details on my work-in-progress will be send to this list later.
>
> - Kris
Rémi
>
> On 2013/3/21 1:23, Jochen Theodorou wrote:
>> Hi all,
>>
>> assuming I have in Java a method:
>>
>> public static Object invoke(MethodHandle mh, Object[] args) {
>> try {
>> return mv.invokeWithArguments(args);
>> } catch (Throwable th) {
>> ExceptionUtils.sneakyThrow(th);
>> }
>> }
>>
>> (sneakyThrow is to work around checked exceptions and does basically
>> just throw the throwable again without declaring it)
>>
>> I am wondering if the call site in this method can become megamorphic or
>> not. And assuming it does not, I further assume the call to this method
>> cannot become megamorphic as well... so my next question is if that can
>> be always be potentially inlined then.
>>
>> bye blackdrag
>>
> _______________________________________________
> mlvm-dev mailing list
> mlvm-dev@openjdk.java.net
> http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
_______________________________________________
mlvm-dev mailing list
mlvm-dev@openjdk.java.net
http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
