Specialize code generation for(build time) compiled Machines

[andreaTP]

Currently we pay the price of boxing and unboxing the arguments even if when not needed.

In the generated ModuleExports class we are invoking functions using the generic lookup mechanism:

instance.exports().function("xyz");

When the module is compiled(especially build-time), we can optimize and generate the direct invocation without boxing/unboxing, something like:

MyModuleMachineFuncGroup_0.func_123(arg0, arg1);

[chirino]

@andreaTP what would you like the interface to get that information look like? Maybe a json resource file:

Maybe something like:

namespace.MyModuleMachine.json:

{
    "function_groups": {
        "namespace.MyModuleMachineFuncGroup_0": {
           "func_123": {
               "index": 123,     
               "args": ["int", "long"],
               "return": "long"
           }
        }
    } 
}

[andreaTP]

Ideally we should not introduce extra dependencies ...
Maybe using a custom section and injecting it in the .meta file?
We already have the type info in the type section, the missing piece of information, I think, is only the Group number

[chirino]

So are you saying something like a .meta section that is an array of int where the index is the function id and value is the group number?

[andreaTP]

We are producing a .meta file which is a valid Wasm payload, we can write, in it, a Custom Section containing this information.
Haven't thought deeply about it ... just a proposal.

[chirino]

Started a branch at https://github.com/chirino/chicory/tree/func-group-section that adds that data the annotation processor would need.