asm.js

since 2013-03
source-to-source compiler
由 WebAssembly 替代 - 2017+
asm.js-specific optimizations
- Chrome 28+
- Firefox 22+
limiting language features to improve performance
"use asm"
参考
- Wikipedia:Asm.js
- asmjs.org/spec/latest

int f(int i) {
  return i + 1;
}

JavaScript

function f(i) {
  i = i | 0;
  return (i + 1) | 0;
}

JavaScript

const HEAP8 = new Int8Array(e);
const HEAP16 = new Int16Array(e);
const HEAP32 = new Int32Array(e);
const HEAPU8 = new Uint8Array(e);
const HEAPU16 = new Uint16Array(e);
const HEAPU32 = new Uint32Array(e);
const HEAPF32 = new Float32Array(e);
const HEAPF64 = new Float64Array(e);

关联信息

参考资料