[wongarsu]

I think using the polyfill as a baseline in the benchmark is misleading. Of course implementing SIMD is faster than emulating it in JavaScript, but nobody cares about that. What everyone is interested in is: How much faster is their SIMD implementation over a normal everyday non-SIMD implementation of the same algorithm. The whole article doesn't even acknowledge that question.

Given that SIMD should bring about a 4 times speedup and yet the polyfill is 17 times slower than the Ion SIMD version and 40 times slower than the asm.js SIMD version, it seem likely that an implementation of the same algorithm without SIMD or polyfill would vastly outperform the polyfill too.

[TazeTSchnitzel]

I was going to say the same. A polyfill will be more complex than, say:

  a[0] *= b[0];
  a[1] *= b[1];
  a[2] *= b[2];
  a[3] *= b[3];