Simple WebAssembly fibonacci performance test

README.md

Simple, quick performance demo / test comparing JavaScript and WebAssembly. Uses fibonacci (n = 40) with 31 runs.

Convert fib.wat to wasm using wat2wasm tool and download as fib.wasm.

Use Node.js 10.

Run:

node index.js

Sample result:

[WASM] total: 21083.41 ms average: 680.11 ms
[JS] total: 38589.46 ms average: 1244.82 ms

fib.wat

(module
 (export "fib" (func $fib))
 (func $fib (param $n i32) (result i32)
  (if
   (i32.lt_s
    (get_local $n)
    (i32.const 2)
   )
   (return
    (i32.const 1)
   )
  )
  (return
   (i32.add
    (call $fib
     (i32.sub
      (get_local $n)
      (i32.const 2)
     )
    )
    (call $fib
     (i32.sub
      (get_local $n)
      (i32.const 1)
     )
    )
   )
  )
 )
)

index.js

const fs = require('fs')
const util = require('util')
const path = require('path')
const readFile = util.promisify(fs.readFile)
const { PerformanceObserver, performance } = require('perf_hooks')

async function main () {
  const buf = await readFile(path.resolve(__dirname, './fib.wasm'))

  const res = await WebAssembly.instantiate(new Uint8Array(buf.buffer))

  const { fib } = res.instance.exports

  bench('WASM', fib)
  bench('JS', fibonacci)
}

function bench (label, fn) {
  const N_ITERS = 30

  const observations = []
  const obs = new PerformanceObserver(list => {
    const entries = list.getEntries()
    observations.push(...entries)
    performance.clearMarks()
  })

  obs.observe({ entryTypes: ['measure'] })

  for (let i = 0; i <= N_ITERS; ++i) {
    performance.mark('A')
    fn(40)
    performance.mark('B')
    performance.measure('A to B', 'A', 'B')
  }

  const total = observations.reduce((total, e) => total + e.duration, 0)
  const avg = total / observations.length
  const totalFx = Number.parseFloat(total).toFixed(2)
  const avgFx = Number.parseFloat(avg).toFixed(2)
  console.log(`[${label}] total: ${totalFx} ms average: ${avgFx} ms`)
}

function fibonacci (num) {
  if (num <= 1) return 1

  return fibonacci(num - 1) + fibonacci(num - 2)
}

main()