[azakai]

There are lots of issues, can take a while to find all the use cases in them (work has been ongoing for some time). But from memory I can recall that

https://github.com/johnmccutchan/ecmascript_simd/issues/59

is interesting here, it mentions, among other things, the major SIMD-using code portion from an important real-world codebase (IMVU).

Might also be relevant discussion on the emscripten repo,

https://github.com/kripken/emscripten/issues?q=is%3Aopen+is%...

as some debate happened there while implementing code generation that emits SIMD.js.