Why is LambdaMetafactory 10% slower than a static MethodHandle but 80% faster than a non-static MethodHandle?

[Jochen Theodorou]

On 19.02.2018 14:31, Vladimir Ivanov wrote:
[...]
> CallSites are the best you can get (JITs treat CallSite.target as 
> constant and aggressively inlines through them), but you have to bind 
> CallSite instance either to invokedynamic call site or put it into 
> static final field.

And that really extends to MutableCallsite? In a dynamic language where 
you depend on the instance types you cannot do all that much with a 
non-mutable callsite.

[...]
> The best thing you can do is to wrap method handle constant into a newly 
> created class (put it into constant pool or static final field) and 
> define a method which invokes the method handle constant (both indy & 
> MH.invokeExact() work). The method should either implement a method from 
> super-interface or overrides a method from a super-class (so there's a 
> way to directly reference it at use sites). The latter is preferable, 
> because invokevirtual is faster than invokeinterface. (LambdaMetafactory 
> does the former and that's the reason it can't beat MH.invokeExact() on 
> non-constant MH).

that is indeed something to try, nice idea. Now finding the time to 
actually do it :(

bye Jochen