使用Javascript ArrayBuffer执行XOR的最快方法

Question

I have a class representing bits and it uses ArrayBuffers to store the binary data. I'm trying to figure out if there is a faster method to perform a xor between two ArrayBuffers .

Note The length of the ArrayBuffers are usually less than 10 bytes. But since the xor operation is performed millions, if not billions of times, every millisecond saved matters.

// my current/simple method
// assume 'buf1', 'buf2' & 'result' are ArrayBuffers
for (var i=0; i<result.length; i++) {
  result[i] = buf1[i] ^ buf2[i];
}

Note Seeking solution executable both locally and on browser.

Answer 1

I know of 4 ways to calculate XOR :

• the native ^ operator
• (n1+n2)%2
• n1+n2-2*n1*n2
• use a preset array: xor=[[0,1],[1,0]]

I ran the following code, you can see the results for yourself:

 buf1=new Array(10000).fill(1).map((x)=>Math.floor(Math.random()*2)); buf2=new Array(10000).fill(1).map((x)=>Math.floor(Math.random()*2)); console.time('go'); for (let i=0;i<10000;i++) r=buf1[i]^buf2[i]; console.timeEnd('go'); console.time('go'); for (let i=0;i<10000;i++) r=(buf1[i]+buf2[i])%2; console.timeEnd('go'); console.time('go'); for (let i=0;i<10000;i++) r=buf1[i]+buf2[i]-2*buf1[i]*buf2[i]; console.timeEnd('go'); xor=[[0,1],[1,0]]; console.time('go'); for (let i=0;i<10000;i++) r=xor[buf1[i]][buf2[i]]; console.timeEnd('go'); 

All the methods seem to give similar results.