"I want to play around with what is essentially profile guided optimization, but with runtime type information. So you get a partially specialized (at least as

"I want to play around with what is essentially profile guided optimization, but with runtime type information. So you get a partially specialized (at least as much as the static compilation can give you) implementation, which then records type information at runtime." Very advanced optimizations. Emscripten doesn't do that (not yet, but LLVM has PGO).