[monopede]

I don't think assemblers written in assembly were that bad. LuaJIT 2 uses direct threading (not new at all), register-based bytecode (relatively new), and manually optimised register assignment (perhaps new). AFAICT, the key innovations are that he did not use Lua 5.1's register-based bytecode format, but simplified it even further so it can be decoded efficiently on x86. The second key component is that he pre-decodes the following instruction in order to take advantage of out-of-order execution. This technique also required fixing some register's roles.

Don't get me wrong, I think LuaJIT2's interpreter is great, but interpreters before LuaJIT2 weren't complete crap, either. Many emulators, for example, have very good interpreters written in assembly (some aim to be cycle-accurate).

[pbiggar]

I was trying to describe how it looked from an academic standpoint. Direct threading and register bytecode was well known (register stuff is actually very old, but the jury was out until about 2003), but everything else Pall did was basically new to programming language researchers and implementers.