RFR: 8347901: C2 should remove unused leaf / pure runtime calls [v2]

[Emanuel Peter]

On Fri, 20 Jun 2025 08:10:54 GMT, Marc Chevalier <mchevalier at openjdk.org> wrote:

>> src/hotspot/share/opto/multnode.hpp line 113:
>> 
>>> 111:   const TypeTuple* _tf;
>>> 112: 
>>> 113:   template <typename... NN>
>> 
>> Does this need to be a template? Or would a type like `Node*` or `Node` suffice?
>
> The point is that it's a variadic template. Of course, ideally, I'd like it to be a pack of `Node*` but there isn't a simple way to write that. The upside is that one can write `TupleNode::make(some_type, input1, input2, input3, input4)` with how many input you want in a single construction. I prefer hiding the not nice here, to have compact and readable usages of TupleNode, rather than having every usage look like
> 
> TupleNode* tuple = new TupleNode(some_type);
> tuple.set_req(0, input1);
> tuple.set_req(1, input2);
> tuple.set_req(2, input3);
> tuple.set_req(3, input4);

Yes, it looks good enough :)

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PR Review Comment: https://git.openjdk.org/jdk/pull/25760#discussion_r2159042194