/// <summary>
/// Shifts and optionally precision-extends the arguments to prepare for Div_32
/// </summary>
/// <param name="n1"></param>
/// <param name="n2"></param>
private static int MakeSafeDiv(BigInt n1, BigInt n2)
{
int shift = n2.GetDivBitshift();
int n1MSD = n1.GetMSD();
uint temp = n1.digitArray[n1MSD];
if (n1MSD == n1.digitArray.Length - 1 && ((temp << shift) >> shift) != n1.digitArray[n1MSD])
{
//Precision-extend n1 and n2 if necessary
int digits = n1.digitArray.Length;
n1.SetNumDigits(digits + 1);
n2.SetNumDigits(digits + 1);
}
//Logical left-shift n1 and n2
n1.LSH(shift);
n2.LSH(shift);
return shift;
}