RFR (S) 8150669: C1 intrinsic for Class.isPrimitive

[Christian Thalinger]

> On Feb 25, 2016, at 10:56 AM, Aleksey Shipilev <aleksey.shipilev at oracle.com> wrote:
> 
> Hi,
> 
> I would like to amend C1 with handling Class.isPrimitive intrinsic:
>  http://cr.openjdk.java.net/~shade/8150669/webrev.01/
>  https://bugs.openjdk.java.net/browse/JDK-8150669
> 
> Through a long chain of dependencies, it would benefit String
> concatenation, possibly startup (lots of usages in java.lang.invoke, and
> who knows how many other places in JDK that use reflective meddling),
> and also, for a fun of it, fastdebug builds.

Can you explain the fastdebug comment a bit?  Have we seen real issues or is this just a nice side-effect?

> 
> Performance data shows we improve all interesting cases:
>  http://cr.openjdk.java.net/~shade/8150669/notes.txt
> 
> Testing: new test; targeted benchmarks; JPRT -testset hotspot
> 
> Thanks,
> -Aleksey
>