private static int CompareBaseBits(int bitsPerDigit, long n)
{ //middle digit <= n * (base - 1) ^ 2 + [2^(128 - bitsPerDigit)] <= P - 1
ulong[] value = new ulong[1];
ulong[] square = new ulong[value.Length * 2];
ulong[] multiplier = new ulong[square.Length];
ulong[] result = new ulong[square.Length * 2];
ulong[] adder = new ulong[result.Length];
value[0] = (1UL << bitsPerDigit) - 1;
multiplier[0] = (ulong)n;
AsmX64Operations.Square(value, square, value.Length);
AsmX64Operations.Multiply(square, multiplier, result, square.Length);
if (128 - bitsPerDigit < 64)
{
adder[0] = 1UL << (128 - bitsPerDigit);
}
else
{
adder[1] = 1UL << (64 - bitsPerDigit);
}
AsmX64Operations.Add(result, adder, result, 0, result.Length);
if (result[2] > 0 || result[3] > 0 || (result[0] >= FourierPoint.PrimeModulo.Low && result[1] == ulong.MaxValue))
{
return(1);
}
if (result[0] == FourierPoint.PrimeModulo.Low - 1 && result[1] == ulong.MaxValue)
{
return(0);
}
return(-1);
}
public static IntegerNumber operator +(IntegerNumber number1, IntegerNumber number2)
{
if (number1.IsNegative != number2.IsNegative)
{
return(number2.IsZero ? number1 : number1 - (-number2));
}
IntegerNumber source1 = number1.ExtendTo(number2.Digits);
IntegerNumber source2 = number2.ExtendTo(number1.Digits);
ulong[] result = new ulong[source1.Digits];
byte carry = AsmX64Operations.Add(source1.bits, source2.bits, result, 0, result.Length);
if (carry != (byte)(result[result.Length - 1] >> 63))
{
Array.Resize(ref result, result.Length + 1);
result[result.Length - 1] = carry == 0 ? 0UL : ulong.MaxValue;
}
return(new IntegerNumber(result, false));
}
