[acqq]

They however got a small, just 50% speedup, which doesn't sound like any static types were really used. They'd be able to get something like 100 times faster FPU calculations, for example if they'd knew the variable is only used as the number and nothing else. I know that factor since I measured the overhead of CPython in FPU calculations, and you can also see http://shootout.alioth.debian.org/u32q/benchmark.php?test=al....

I guess they call everything that would be called for each variable reference in CPython (including checks like "is this a string or a number or...") and that they save more or less just in having the calls encoded one after another, and maybe some internal arguments needed for that, but not in knowing the types.