I want "use asm" as a way of getting extra 'compile time' checking.
If I say "use asm" and do something that isn't optimizable by mistake, it should give me an error rather than silently falling back to slow code.
If I say "use asm" and do something that isn't optimizable by mistake, it should give me an error rather than silently falling back to slow code.
Interestingly enough, this makes the V8 approach all the more welcome since it doesn't break backwards compatibility.
Firefox will warn about asm.js validation errors, but those are just warnings in the web console. They do not affect semantics of execution at all, and are undetectable by the running code. So the code will run identically in all browsers regardless of whether it happens to fall in the asm.js subset or not.