davidaurelio/index.html

## index.html
<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8"/>
	<title>count bits</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
</head>
<body>
	<h1>Open the console to view the results</h1>
	<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
</body>
</html>

## suite.js
"use strict";

(function (factory) {
	if (typeof Benchmark !== "undefined") {
		factory(Benchmark);
	} else {
		factory(require("benchmark"));
	}
})(function (Benchmark) {
	var suite = new Benchmark.Suite;

	Benchmark.prototype.setup = function () {
		const table = new Int32Array(256);
		for (let i = 0; i < table.length; ++i) table[i] = (i & 1) + table[i / 2];

		function tableLookup(n) {
		    return table[n & 0xff] + table[(n >>> 8) & 0xff] + table[(n >>> 16) & 0xff] + table[n >>> 24];
		}

		function bitFiddling(v) {
		    v = v - ((v >>> 1) & 0x55555555);
		    v = (v & 0x33333333) + ((v >>> 2) & 0x33333333);
		    return ((v + (v >>> 4) & 0xF0F0F0F) * 0x1010101) >>> 24;
		}

		function naive(v) {
		    let bits = 0;
		    while (v) {
		        bits += v & 1;
		        v >>>= 1;
		    }
		    return bits;
		}

		function assert(condition, message) {
		    if (!condition) throw new Error(message);
		}

		const int32s = [
		    0,
		    1, -1, -2, -1061915544, -1555347375,
		    1120351692, -563428345,
		    863023321, -1455766619,
		    1090078114,
		    1545926896,
		    353401604,
		    1926705176,
		    2066963906,
		    1310154921,
		    794500772, -293685467,
		    635914052, -696870554, -685960877, -1564768615, -908098734,
		    1997198644, -1696246300,
		    787069003, -773953043, -235755836,
		    1825707196, -1413376694, -1332116542,
		    810036644, -1837823121, -722610458, -97543692,
		    1086944003, -1247712344,
		    104166236, -705871200, -544442644, -67279285,
		    842775500,
		    798080844, -557572388, -262737337, -1203086408, -127658972, -1045852068, -1457067762, -1410023778, -1096304808, -315755944,
		    889378202,
		    34525992,
		    773371328, -521213376, -495050220,
		    385953520,
		    1720432991,
		    2082574462,
		    1062332896,
		    769181290,
		    144354176,
		    1145499621, -653353083,
		    1488676250,
		    408064013,
		    219026518, -850128992,
		    1989039182,
		    503186529, -869520878,
		    1344526480, -331372343,
		    22089576,
		    326802570, -1798031256,
		    2083475736, -1045800478, -429869316, -287023120, -1897640640, -108797603, -509689151, -1979205164, -591203265, -1236105036,
		    1730724752, -1479716844, -1509702343,
		    1822319432, -1993357146, -664865913, -1269187636,
		    484933660, -968168341,
		    1387535965, -1226749615, -574704542,
		    1162372512, -1852546033,
		    991446254, -266798208,
		    1868632965,
		    1718674624, -1342068840,
		    334601446,
		    1845086418,
		    2078681314, -1572654006, -909790936, -1051593787, -727234566, -220199360, -1238855763,
		    962218858,
		    193290686,
		    1320017958,
		    477544672,
		    699625336,
		    1876829198, -405126864,
		    1605412660, -1679238464, -1489968018,
		    692546469, -559532124,
		    1511711040
		];

		const expected = int32s.map(naive);
		const results = int32s.slice().fill(NaN);
	};

	Benchmark.prototype.teardown = function () {
		int32s.forEach((n, i) => assert(results[i] === expected[i], `Wrong result for ${n}`));
	};

	suite.add("for (let i = 0, n = int32s.length; i < n; ++n)", function () {
		for (let i = 0, n = int32s.length; i < n; ++n)
		  results[i] = tableLookup(int32s[i]);
	});

	suite.add("for (let i = 0, n = int32s.length; i < n; ++n)", function () {
		for (let i = 0, n = int32s.length; i < n; ++n)
		  results[i] = bitFiddling(int32s[i]);
	});

	suite.add("for (let i = 0, n = int32s.length; i < n; ++n)", function () {
		for (let i = 0, n = int32s.length; i < n; ++n)
		  results[i] = naive(int32s[i]);
	});

	suite.on("cycle", function (evt) {
		console.log(" - " + evt.target);
	});

	suite.on("complete", function (evt) {
		console.log(new Array(30).join("-"));

		var results = evt.currentTarget.sort(function (a, b) {
			return b.hz - a.hz;
		});

		results.forEach(function (item) {
			console.log((idx + 1) + ". " + item);
		});
	});

	console.log("count bits");
	console.log(new Array(30).join("-"));
	suite.run();
});
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8"/>
	<title>count bits</title>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>
	<script src="./suite.js"></script>
	</head>
	<body>
	<h1>Open the console to view the results</h1>
	<h2><code>cmd + alt + j</code> or <code>ctrl + alt + j</code></h2>
	</body>
	</html>
	"use strict";

	(function (factory) {
	if (typeof Benchmark !== "undefined") {
	factory(Benchmark);
	} else {
	factory(require("benchmark"));
	}
	})(function (Benchmark) {
	var suite = new Benchmark.Suite;

	Benchmark.prototype.setup = function () {
	const table = new Int32Array(256);
	for (let i = 0; i < table.length; ++i) table[i] = (i & 1) + table[i / 2];

	function tableLookup(n) {
	return table[n & 0xff] + table[(n >>> 8) & 0xff] + table[(n >>> 16) & 0xff] + table[n >>> 24];
	}

	function bitFiddling(v) {
	v = v - ((v >>> 1) & 0x55555555);
	v = (v & 0x33333333) + ((v >>> 2) & 0x33333333);
	return ((v + (v >>> 4) & 0xF0F0F0F) * 0x1010101) >>> 24;
	}

	function naive(v) {
	let bits = 0;
	while (v) {
	bits += v & 1;
	v >>>= 1;
	}
	return bits;
	}

	function assert(condition, message) {
	if (!condition) throw new Error(message);
	}

	const int32s = [
	0,
	1, -1, -2, -1061915544, -1555347375,
	1120351692, -563428345,
	863023321, -1455766619,
	1090078114,
	1545926896,
	353401604,
	1926705176,
	2066963906,
	1310154921,
	794500772, -293685467,
	635914052, -696870554, -685960877, -1564768615, -908098734,
	1997198644, -1696246300,
	787069003, -773953043, -235755836,
	1825707196, -1413376694, -1332116542,
	810036644, -1837823121, -722610458, -97543692,
	1086944003, -1247712344,
	104166236, -705871200, -544442644, -67279285,
	842775500,
	798080844, -557572388, -262737337, -1203086408, -127658972, -1045852068, -1457067762, -1410023778, -1096304808, -315755944,
	889378202,
	34525992,
	773371328, -521213376, -495050220,
	385953520,
	1720432991,
	2082574462,
	1062332896,
	769181290,
	144354176,
	1145499621, -653353083,
	1488676250,
	408064013,
	219026518, -850128992,
	1989039182,
	503186529, -869520878,
	1344526480, -331372343,
	22089576,
	326802570, -1798031256,
	2083475736, -1045800478, -429869316, -287023120, -1897640640, -108797603, -509689151, -1979205164, -591203265, -1236105036,
	1730724752, -1479716844, -1509702343,
	1822319432, -1993357146, -664865913, -1269187636,
	484933660, -968168341,
	1387535965, -1226749615, -574704542,
	1162372512, -1852546033,
	991446254, -266798208,
	1868632965,
	1718674624, -1342068840,
	334601446,
	1845086418,
	2078681314, -1572654006, -909790936, -1051593787, -727234566, -220199360, -1238855763,
	962218858,
	193290686,
	1320017958,
	477544672,
	699625336,
	1876829198, -405126864,
	1605412660, -1679238464, -1489968018,
	692546469, -559532124,
	1511711040
	];

	const expected = int32s.map(naive);
	const results = int32s.slice().fill(NaN);
	};

	Benchmark.prototype.teardown = function () {
	int32s.forEach((n, i) => assert(results[i] === expected[i], `Wrong result for ${n}`));
	};

	suite.add("for (let i = 0, n = int32s.length; i < n; ++n)", function () {
	for (let i = 0, n = int32s.length; i < n; ++n)
	results[i] = tableLookup(int32s[i]);
	});

	suite.add("for (let i = 0, n = int32s.length; i < n; ++n)", function () {
	for (let i = 0, n = int32s.length; i < n; ++n)
	results[i] = bitFiddling(int32s[i]);
	});

	suite.add("for (let i = 0, n = int32s.length; i < n; ++n)", function () {
	for (let i = 0, n = int32s.length; i < n; ++n)
	results[i] = naive(int32s[i]);
	});

	suite.on("cycle", function (evt) {
	console.log(" - " + evt.target);
	});

	suite.on("complete", function (evt) {
	console.log(new Array(30).join("-"));

	var results = evt.currentTarget.sort(function (a, b) {
	return b.hz - a.hz;
	});

	results.forEach(function (item) {
	console.log((idx + 1) + ". " + item);
	});
	});

	console.log("count bits");
	console.log(new Array(30).join("-"));
	suite.run();
	});