Monomorphic vs megamorphic vs typed modes benchmark

result.txt

Monomorphic x 1,989 ops/sec ±1.90% (71 runs sampled)
Megamorphic x 47.27 ops/sec ±1.03% (58 runs sampled)
Typed x 2,550 ops/sec ±2.10% (57 runs sampled)

v8-optimization.bench.js

const Benchmark = require('benchmark');

const suite = new Benchmark.Suite;

// Test data set size
const n = process.env.SET_SIZE || 100000;
// Monomorhpic objects array
const mono = Array(n);
// Megamorphic objects array
const mega = Array(n);
// Typed objects array
const typed = Array(n);

function Type(i) {
    this.x =i;
    this.n = null;
}

// Pregenerate objects
for (let i = 0; i < n; i++) {
    mono[i] = {
        n: null, // Add n to balance memory usage
        x: i,
    };

    mega[i] = {};
    mega[i]['k' + i] = null;
    mega[i].x = i;

    typed[i] = new Type(i);
}

function monoform(x) {
    return x.x + x.x;
}

function megaform(x) {
    return x.x + x.x;
}

function typedform(x) {
    return x.x + x.x;
}

suite
.add('Monomorphic', function() {
    for (var i = 0; i < n; i++) {
        monoform(mono[i]);
    }
})
.add('Megamorphic', function() {
    for (var i = 0; i < n; i++) {
        megaform(mega[i]);
    }
})
.add('Typed', function() {
    for (var i = 0; i < n; i++) {
        typedform(typed[i]);
    }
})
.on('error', error => {
    console.error(error);
})
// add listeners
.on('cycle', function(event) {
  console.log(String(event.target));
})
.on('complete', function() {
  console.log('Fastest is ' + this.filter('fastest').map('name'));
})
// run async
.run({async: false});