3 ms·

On the other hand, you could compile well-behaved subsets of JavaScript into wasm. Kind of what asm.js was doing. Whether that's useful in practice is an open

by Yoric 9y ago

On the other hand, you could compile well-behaved subsets of JavaScript into wasm. Kind of what asm.js was doing. Whether that's useful in practice is an open question, but it's plausible.

sjrd 9y ago
asm.js was not a well-behaved subset of JavaScript. It was a well-behaved subset of assembly that happened to be encoded in JavaScript. There is virtually no human-written JS code that is amenable to compilation to wasm in a meaningful way. At the very least, you need a (mostly) sound type system to be able to compile to wasm with a positive expected ROI. The speed of wasm comes in a large part from the fact that it is entirely statically typed, which means we don't need the speculative optimizations (and their deoptimization guards) all over the place.
- jahewson 9y ago
  Exactly, plus in a dynamic environment a tracing JIT can outperform AOT compiled code. This is true for both the JVM and .NET CLR, both mature platforms.
- Zekio 9y ago
  Wonder if there will ever be a version of typescript that compiles to wasm
jahewson 9y ago
It’s really inaccurate to call that “JavaScript” any more. You’re talking about a subset of JS that would never need to perform a GC! Really just “the subset of JavaScript which also happens to be C”.