jsPerf.app is an online JavaScript performance benchmark test runner & jsperf.com mirror. It is a complete rewrite in homage to the once excellent jsperf.com now with hopefully a more modern & maintainable codebase.
jsperf.com URLs are mirrored at the same path, e.g:
https://jsperf.com/negative-modulo/2
Can be accessed at:
https://jsperf.app/negative-modulo/2
My implementation is based on the observation that Javascript is not limited to exactly to 32-bit integers. Rather, it internally represents integers as double-precision floats. Therefore it is limited to 52-bit integers (the mantissa length). 52 bits is enough to contain 48 bits and therefore it is able to contain the result of multiplying 32-bit and 16-bit numbers without loss of lower bits. This observation enables the algorithm to be implemented so that it requires less operations to emulate 32-bit multiplications, as compared to an algorithm that uses 16-bit multiplications to emulate 32-bit multiplications. Also because of that, addition of 32-bit operands can be performed simpler.
The code of my version can be downloaded at https://github.com/levitation/murmurhash-js
/**
* JS Implementation of MurmurHash3 (r136) (as of May 20, 2011)
*
* @author <a href="mailto:gary.court@gmail.com">Gary Court</a>
* @see http://github.com/garycourt/murmurhash-js
* @author <a href="mailto:aappleby@gmail.com">Austin Appleby</a>
* @see http://sites.google.com/site/murmurhash/
*
* @param {string} key ASCII only
* @param {number} seed Positive integer only
* @return {number} 32-bit positive integer hash
*/
function murmurhash3_32_gc(key, seed) {
var remainder, bytes, h1, h1b, c1, c1b, c2, c2b, k1, i;
remainder = key.length & 3; // key.length % 4
bytes = key.length - remainder;
h1 = seed;
c1 = 0xcc9e2d51;
c2 = 0x1b873593;
i = 0;
while (i < bytes) {
k1 =
((key.charCodeAt(i) & 0xff)) |
((key.charCodeAt(++i) & 0xff) << 8) |
((key.charCodeAt(++i) & 0xff) << 16) |
((key.charCodeAt(++i) & 0xff) << 24);
++i;
k1 = ((((k1 & 0xffff) * c1) + ((((k1 >>> 16) * c1) & 0xffff) << 16))) & 0xffffffff;
k1 = (k1 << 15) | (k1 >>> 17);
k1 = ((((k1 & 0xffff) * c2) + ((((k1 >>> 16) * c2) & 0xffff) << 16))) & 0xffffffff;
h1 ^= k1;
h1 = (h1 << 13) | (h1 >>> 19);
h1b = ((((h1 & 0xffff) * 5) + ((((h1 >>> 16) * 5) & 0xffff) << 16))) & 0xffffffff;
h1 = (((h1b & 0xffff) + 0x6b64) + ((((h1b >>> 16) + 0xe654) & 0xffff) << 16));
}
k1 = 0;
switch (remainder) {
case 3: k1 ^= (key.charCodeAt(i + 2) & 0xff) << 16;
case 2: k1 ^= (key.charCodeAt(i + 1) & 0xff) << 8;
case 1: k1 ^= (key.charCodeAt(i) & 0xff);
k1 = (((k1 & 0xffff) * c1) + ((((k1 >>> 16) * c1) & 0xffff) << 16)) & 0xffffffff;
k1 = (k1 << 15) | (k1 >>> 17);
k1 = (((k1 & 0xffff) * c2) + ((((k1 >>> 16) * c2) & 0xffff) << 16)) & 0xffffffff;
h1 ^= k1;
}
h1 ^= key.length;
h1 ^= h1 >>> 16;
h1 = (((h1 & 0xffff) * 0x85ebca6b) + ((((h1 >>> 16) * 0x85ebca6b) & 0xffff) << 16)) & 0xffffffff;
h1 ^= h1 >>> 13;
h1 = ((((h1 & 0xffff) * 0xc2b2ae35) + ((((h1 >>> 16) * 0xc2b2ae35) & 0xffff) << 16))) & 0xffffffff;
h1 ^= h1 >>> 16;
return h1 >>> 0;
}
/**
* JS Implementation of MurmurHash3 (r152) (as of May 10, 2013)
*
* @author <a href="mailto:roland@simplify.ee">Roland Pihlakas</a>
* @see http://github.com/levitation/murmurhash-js
* @author <a href="mailto:aappleby@gmail.com">Austin Appleby</a>
* @see https://code.google.com/p/smhasher/
*
* @param {string} key ASCII only
* @param {number} seed positive integer only
* @return {number} 32-bit positive integer hash
*/
function murmurhash3_32_rp(key, seed) {
var keyLength, tailLength, bodyLength, h1, k1, i, c1_low, c1_high, c2_low, c2_high;
keyLength = key.length;
tailLength = keyLength & 3;
bodyLength = keyLength - tailLength;
h1 = seed;
//c1 = 0xcc9e2d51;
c1_low = 0x2d51;
c1_high = 0xcc9e0000;
//c2 = 0x1b873593;
c2_low = 0x3593;
c2_high = 0x1b870000;
//----------
// body
i = 0;
while (i < bodyLength) {
k1 =
((key.charCodeAt(i) & 0xff)) |
((key.charCodeAt(++i) & 0xff) << 8) |
((key.charCodeAt(++i) & 0xff) << 16) |
((key.charCodeAt(++i) & 0xff) << 24);
++i;
//k1 *= c1;
k1 = (c1_high * k1 | 0) + (c1_low * k1);
//k1 = ROTL32(k1,15);
k1 = (k1 << 15) | (k1 >> 17);
//k1 *= c2;
k1 = (c2_high * k1 | 0) + (c2_low * k1);
//h1 ^= k1;
h1 ^= k1;
//h1 = ROTL32(h1,13);
h1 = (h1 << 13) | (h1 >>> 19);
//h1 = h1*5+0xe6546b64;
h1 = h1 * 5 + 0xe6546b64;
} //while (i < bodyLength) {
//----------
// tail
k1 = 0;
switch (tailLength) {
case 3: k1 ^= (key.charCodeAt(i + 2) & 0xff) << 16;
case 2: k1 ^= (key.charCodeAt(i + 1) & 0xff) << 8;
case 1: k1 ^= (key.charCodeAt(i) & 0xff);
//k1 *= c1;
k1 = (c1_high * k1 | 0) + (c1_low * k1);
//k1 = ROTL32(k1,15);
k1 = (k1 << 15) | (k1 >> 17);
//k1 *= c2;
k1 = (c2_high * k1 | 0) + (c2_low * k1);
//h1 ^= k1;
h1 ^= k1;
} //switch (tailLength) {
//----------
// finalization
h1 ^= keyLength;
//h1 = fmix32(h1);
{
//h ^= h >> 16;
h1 ^= h1 >>> 16;
//h1 *= 0x85ebca6b;
h1 = (0x85eb0000 * h1 | 0) + (0xca6b * h1);
//h ^= h >> 13;
h1 ^= h1 >>> 13;
//h1 *= 0xc2b2ae35;
h1 = (0xc2b20000 * h1 | 0) + (0xae35 * h1);
//h ^= h >> 16;
h1 ^= h1 >>> 16;
}
return h1 >>> 0; //convert to unsigned int
} //function murmurhash3_32_rp(key, seed) {
var i, s10, s1k, s1m = "",
a10 = [], a1k = [];
a10.length = 10;
a1k.length = 1024;
s10 = String.fromCharCode.apply(null, a10.map(function() {
return ((Math.random() * 256) | 0);
}));
s1k = String.fromCharCode.apply(null, a1k.map(function() {
return ((Math.random() * 256) | 0);
}));
for (i = 0; i < 1024; i++) s1m = s1m.concat(s1k);Ready to run.
| Test | Ops/sec | |
|---|---|---|
| 10-char string: MurmurHash3 by Gary Court | | ready |
| 10-char string: MurmurHash3 by Roland Pihlakas | | ready |
| 1k string: MurmurHash3 by Gary Court | | ready |
| 1k string: MurmurHash3 by Roland Pihlakas | | ready |
| 1M string: MurmurHash3 by Gary Court | | ready |
| 1M string: MurmurHash3 by Roland Pihlakas | | ready |
You can edit these tests or add more tests to this page by appending /edit to the URL.