[kivikakk]

> the subset that it optimized for would still be C

This doesn't mean to imply the subset is the entirety of C; it means the subset is part of the definition of C — just like you can say "'int x = 4;' is C", even though it's a (demonstration of a) subset of C.

The JavaScript which happens to be optimised under the name "asm.js" is still JavaScript that executes in any non-optimising runtime, and the semantics with those optimisations and without are the same.

[stoptalkingshit]

Javascript was the wrong design choice, and the asm.js people are very sensitive about this. Which is why they pretend it's "just Javascript". Nobody denies that it's backward compatible. But it is a new language, the rest is word games.