Add gas costs

[adlerjohn]

Opcodes currently don't have gas costs. These need to be specified.

[SilentCicero]

What is our current strategy for pricing?

Will it have to be based upon real world benchmarking?

[adlerjohn]

Run lots of benchmarks with as clean a setup as possible. That's really the only way.

[SilentCicero]

@adlerjohn can we placeholder some initial values for now, than adjust them based upon real world benchmarks?

This would help just for implementation and testing before we get to benchmarking.

[adlerjohn]

The implementation can just choose some sane values. There's no reason to pollute the specs with that.

[Voxelot]

@adlerjohn this could likely be closed, as we now have a gas schedule benchmarking framework that we are iterating on.

[otrho]

Don't we want them properly documented somewhere? If I wanted to know individual op costs (which I do when writing optimisers) where should I look?

[Voxelot]

We are working on a framework to autogenerate a yaml file of the costs based on bechmarks, and also generate a rust file which contains the instantiated gas costs.

As we expect the gas costs to change over time as we add more functionality like merkle trees or optimize the vm/client, I'm not sure if statically binding them to the specs is the best move right now.