Albert@Mar 2018

WebAssembly is a binary instruction format for a stack-based virtual

machine. WebAssembly is designed as a portable target for

compilation of high-level languages like C/C++/Rust, enabling

deployment on the web for client and server applications.

Define a portable, size- and load-time-efficient binary format to serve

as a compilation target which can be compiled to execute at native

speed by taking advantage of common hardware capabilities available

on a wide range of platforms, including mobile and IoT.

Parse

Compiling + optimizing

Re-optimize

Execut

https://webassembly.org/docs/binary-encoding/#why-a-binary-encoding-instead-of-a-

text-only-representation

https://webassembly.org/docs/use-cases/

Emen

source.c -----> target.js

Emen (with flag)

source.c -----> target.wasm

Binaryen WABT

math.js ---> math.wast ---> math.wasm

linear assembly

bytecode

Chrome: 打开 chrome://flags/#enable-webassembly，enable。

C/C++ >> WebAssembly

emcc math.c -Os -s WASM=1 -s SIDE_MODULE=1 -o math.wasm

C/C++ >> WebAssembly

C/C++ >> WASM

asm.js >> WASM

Binaryen WABT

math.js ---> math.wast ---> math.wasm

asm2wasm math.js -o math.wast

wast2wasm math.wast -o math.wasm

asm.js >> WASM

Binaryen WABT

math.js ---> math.wast ---> math.wasm

asm2wasm math.js -o math.wast

wast2wasm math.wast -o math.wasm

WASM + exit.js

new WebAssembly.Table(）

More Examples

Events.emit(‘Thanks’)

console.log(‘End’);