/**
* Returns the number of bits used to store this number. Non-singicant upper bits are not counted.
*
* @param MathAdapterInterface $adapter
* @param int|string $x
* @return number
*
* @link https://www.openssl.org/docs/crypto/BN_num_bytes.html
*/
public static function bnNumBits(MathAdapterInterface $adapter, $x)
{
if ($adapter->cmp($x, '0') == 0) {
return 0;
}
$log2 = 0;
while ($x = $adapter->rightShift($x, 1)) {
$log2++;
}
return $log2 + 1;
}
/**
* @param $integer
* @param $bitSize
* @return bool
*/
public function isNegative($integer, $bitSize)
{
return $this->math->cmp($this->math->rightShift($integer, $this->fixSize($bitSize)), '1') == 0;
}