Run results for: BigInt to BigEndian Bytes (extended by trincot, v3)

Test name	Executions per second
✓ With split	11,788,106 Ops/sec
With split and forward assignment	11,554,508 Ops/sec
Direct Constructor	6,574,462 Ops/sec

Script Preparation code:

function bigIntToUint8ArrayDirectConstructor(value) {
    const result = new Uint8Array(8);
    result[7] = Number(value & 0xffn);
    result[6] = Number((value >> 8n) & 0xffn);
    result[5] = Number((value >> 16n) & 0xffn);
    result[4] = Number((value >> 24n) & 0xffn);
    result[3] = Number((value >> 32n) & 0xffn);
    result[2] = Number((value >> 40n) & 0xffn);
    result[1] = Number((value >> 48n) & 0xffn);
    result[0] = Number((value >> 56n) & 0xffn);
    return result;
}

// Added by trincot: first split BigInt into two numbers (32 bit), then work with those only
function bigIntToUint8ArrayDirectConstructor2(value) {
    const result = new Uint8Array(8);
    const low = Number(value & 0xffffffffn);
    const high = Number(value >> 32n);
    result[7] = low & 0xff;
    result[6] = (low >>> 8) & 0xff;
    result[5] = (low >>> 16) & 0xff;
    result[4] = low >>> 24;
    result[3] = high & 0xff;
    result[2] = (high >>> 8) & 0xff;
    result[1] = (high >>> 16) & 0xff;
    result[0] = high >>> 24;
    return result;
}

// Forward assignment instead of backward
function bigIntToUint8ArrayDirectConstructor3(value) {
    const result = new Uint8Array(8);
    const low = Number(value & 0xffffffffn);
    const high = Number(value >> 32n);
    result[0] = high >>> 24;
    result[1] = (high >>> 16) & 0xff;
    result[2] = (high >>> 8) & 0xff;
    result[3] = high & 0xff;
    result[4] = low >>> 24;
    result[5] = (low >>> 16) & 0xff;
    result[6] = (low >>> 8) & 0xff;
    result[7] = low & 0xff;
    return result;
}

Run results for: BigInt to BigEndian Bytes (extended by trincot, v3)

Direct Constructor

With split

With split and forward assignment