Great work on your emulator. I am also looking forward to use webassembly for my emulator when available. However, I don't expect much speed improvement. I guess you can speed up your emulator significantly by putting in some '|0' noops to prevent deoptimizations into double precision.
Primarily due to the use of asm.js. I intend to implement a JIT similar to QEMU's tcg as soon as Web Assembly supports it: https://github.com/WebAssembly/design/blob/master/FutureFeat...