That's partly what I meant though, how fast is it at a longer running process? C doesn't require all that much semantic analysis so there usually isn't all that

That's partly what I meant though, how fast is it at a longer running process? C doesn't require all that much semantic analysis so there usually isn't all that much hot code in the compiler, so it would suit a simple-fast JIT whereas QEMU does do some basic optimizations. I've only ever really skimmed the TCG source code but it wouldn't surprise me if a new-er JIT could smack it's arse given that with these old C codebases (it's probably one of Bellard's few flaws) it's pretty hard to actually make true architectural changes. The Java/script (I think more Javascript but I'm hedging my bets by including jvms too) JITs are probably the cutting edge but I'd imagine still quite beatable for a few cases.