Very cool, that's a decent performance bump.

It'd be nice to have some simple benchmarks that directly compare ignition, sparkplug and turbofan (and full-codegen too). And also time spent compiling.

It looks somewhat similar to context threading as I remember it:

http://www.cs.toronto.edu/~matz/pubs/demkea_context.pdf

but it's been a while...

Ha-ha, the stacks grow downwards button is priceless :-D