code: function packIEEE754(value, mLen, nBytes) {
    var buffer = Array(nBytes);
    var eLen = nBytes * 8 - mLen - 1;
    var eMax = (1 << eLen) - 1;
    var eBias = eMax >> 1;
    var rt = mLen === 23 ? pow(2, -24) - pow(2, -77) : 0;
    var i = 0;
    var s = value < 0 || value === 0 && 1 / value < 0 ? 1 : 0;
    var e, m, c;
    value = abs(value);
    // eslint-disable-next-line no-self-compare
    if (value != value || value === Infinity) {
      // eslint-disable-next-line no-self-compare
      m = value != value ? 1 : 0;
      e = eMax;
    } else {
      e = floor(log(value) / LN2);
      if (value * (c = pow(2, -e)) < 1) {
        e--;
        c *= 2;
      }
      if (e + eBias >= 1) {
        value += rt / c;
      } else {
        value += rt * pow(2, 1 - eBias);
      }
      if (value * c >= 2) {
        e++;
        c /= 2;
      }
      if (e + eBias >= eMax) {
        m = 0;
        e = eMax;
      } else if (e + eBias >= 1) {
        m = (value * c - 1) * pow(2, mLen);
        e = e + eBias;
      } else {
        m = value * pow(2, eBias - 1) * pow(2, mLen);
        e = 0;
      }
    }
    for (; mLen >= 8; buffer[i++] = m & 255, m /= 256, mLen -= 8);
    e = e << mLen | m;
    eLen += mLen;
    for (; eLen > 0; buffer[i++] = e & 255, e /= 256, eLen -= 8);
    buffer[--i] |= s * 128;
    return buffer;
  }
docs: IEEE754 conversions based on https://github.com/feross/ieee754