var size = 8 * 40;

var srcBuf8 = new ArrayBuffer(size);

var srcBufPtr8 = new Uint8Array(srcBuf8);

var srcBuf16 = new ArrayBuffer(size*2);

var srcBufPtr16 = new Uint16Array(srcBuf16);

var srcBuf32 = new ArrayBuffer(size*4);

var srcBufPtr32 = new Uint32Array(srcBuf32);

var srcBuf64 = new ArrayBuffer(size*8);

var srcBufPtr64 = new BigUint64Array(srcBuf64);

​

for (let i = 0; i < size; i++) {

    srcBufPtr8[i] = 100 * Math.random();

}

for (let i = 0; i < size; i++) {

    srcBufPtr16[i] = srcBufPtr8[i];

}

for (let i = 0; i < size; i++) {

    srcBufPtr32[i] = srcBufPtr8[i];

}

for (let i = 0; i < size; i++) {

    srcBufPtr64[i] = BigInt(srcBufPtr8[i]);

}