Run results for: hashin' nums

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:56.0) Gecko/20100101 Firefox/56.0.1 Waterfox/56.0.1

Browser: Firefox 56

Operating system: Windows 7

Device Platform: Other

Date tested: 2024 years ago

Test name	Executions per second
h1	184.5 Ops/sec
h2	27777.7 Ops/sec
h3	9040.5 Ops/sec
h4	26079.9 Ops/sec

HTML Preparation code:

<script>
'use strict';

const float64 = (a, b) => {
	let x = new Uint32Array(2);
	let y = new Float64Array(x.buffer);
	x[0] = a|0;
	x[1] = b|0;
	return y[0];
};

const float32 = (a) => {
	let x = new Uint32Array(1);
	let y = new Float64Array(x.buffer);
	x[0] = a|0;
	return y[0];
};

const floatParts = (n) => {
	let x = new Uint32Array(2);
	let y = new Float64Array(x.buffer);
	y[0] = n;
	return [...x];
};

const randNum = () =>
	float64(
		(Math.random() * 0xffffffff)|0,
		(Math.random() * 0xffffffff)|0);

const randSpecial = () =>
	float64(
		(Math.random() * 0xffffffff)|0,
		(Math.random() * 0xffffffff)|0b01111111111100000000000000000000);

const nums = [...Array(5000)]
	.map(randNum)
	.concat([NaN, Infinity, -Infinity, -0, +0]);

const h1 = function(n) {
  	'use strict';
	const x = new Uint32Array(2);
	const y = new Float64Array(x.buffer);
	y[0] = n;
	return x[0] ^ x[1];
};

const h2x = new Uint32Array(2);
const h2y = new Float64Array(h2x.buffer);
const h2 = function(n) {
  	'use strict';
	h2y[0] = n;
	return h2x[0] ^ h2x[1];
};
  
  	const h3x = new Uint32Array(2);
	const h3y = new DataView(h3x.buffer);
	const h3 = function(n) {
  		'use strict';
		h3y.setFloat64(0, n, true);
		return h3x[0] ^ h3x[1];
	};
  
const h4 = {
  f(n) {
  	'use strict';
	this.floatArr[0] = n;
	return this.intArr[0] ^ this.intArr[1];
  }
};

h4.intArr = new Uint32Array(2);
h4.floatArr = new Float64Array(h4.intArr.buffer);

  
	const hashModule = function(stdlib, foreign, buffer) {
		'use asm';

		const u32s = new stdlib.Uint32Array(buffer);
		const f64s = new stdlib.Float64Array(buffer);

		function hash(n) {
			n = +n;
			f64s[0] = n;
			return u32s[0] ^ u32s[1];
		};

		return {hash : hash};
	};

	const asmjsHash = hashModule(window, null, new ArrayBuffer(2**16)).hash;

</script>

Tests:

h1
let sum = 0; for (let i = 0, len = nums.length; i < len; ++i) { sum += h1(nums[i]); };
h2
let sum = 0; for (let i = 0, len = nums.length; i < len; ++i) { sum += h2(nums[i]); };
h3
let sum = 0; for (let i = 0, len = nums.length; i < len; ++i) { sum += h3(nums[i]); };
h4
let sum = 0; for (let i = 0, len = nums.length; i < len; ++i) { sum += h4.f(nums[i]); };
asm.js
let sum = 0; for (let i = 0, len = nums.length; i < len; ++i) { sum += asmjsHash(nums[i]); };

Run results for: hashin' nums

h1

h2

h3

h4

asm.js