/// <summary>Compute a*b and store the result to r.</summary>
/// <returns>r</returns>
internal static LongLong Multiplication(LongLong r, long a, long b)
{
/*
* final long x0 = a & LOWER_MASK;
* final long x1 = (a & UPPER_MASK) >> MID;
*
* final long y0 = b & LOWER_MASK;
* final long y1 = (b & UPPER_MASK) >> MID;
*
* final long t = (x0 + x1)*(y0 + y1);
* final long u = (x0 - x1)*(y0 - y1);
* final long v = x1*y1;
*
* final long tmp = (t - u)>>>1;
* result.d0 = ((t + u)>>>1) - v + ((tmp << MID) & FULL_MASK);;
* result.d1 = v + (tmp >> MID);
* return result;
*/
long a_lower = a & LowerMask;
long a_upper = (a & UpperMask) >> Mid;
long b_lower = b & LowerMask;
long b_upper = (b & UpperMask) >> Mid;
long tmp = a_lower * b_upper + a_upper * b_lower;
r.d0 = a_lower * b_lower + ((tmp << Mid) & FullMask);
r.d1 = a_upper * b_upper + (tmp >> Mid);
return(r);
}
internal static void VerifyMultiplication(long a, long b)
{
LongLong ll = LongLong.Multiplication(new LongLong(), a, b);
BigInteger bi = BigInteger.ValueOf(a).Multiply(BigInteger.ValueOf(b));
string s = string.Format("\na = %x\nb = %x\nll= " + ll + "\nbi= " + bi.ToString(16
) + "\n", a, b);
//System.out.println(s);
NUnit.Framework.Assert.AreEqual(s, bi, ll.ToBigInteger());
}
internal virtual long M(long c, long d)
{
LongLong.Multiplication(this.x, c, d);
// a = (x * N')&(R - 1) = ((x & R_1) * N') & R_1
long a = LongLong.Multiplication(this.xN_I, this.x.And(this._enclosing.R1), this.
_enclosing.NI).And(this._enclosing.R1);
LongLong.Multiplication(this.aN, a, this._enclosing.N);
long z = this.aN.PlusEqual(this.x).ShiftRight(this._enclosing.s);
return(z < this._enclosing.N ? z : z - this._enclosing.N);
}
internal static void VerifyRightShift(long a, long b)
{
LongLong ll = new LongLong().Set(a, b);
BigInteger bi = ll.ToBigInteger();
for (int i = 0; i < LongLong.Size >> 1; i++)
{
long result = ll.ShiftRight(i) & Mask;
long expected = bi.ShiftRight(i) & Mask;
string s = string.Format("\na = %x\nb = %x\nll= " + ll + "\nbi= " + bi.ToString(16
) + "\n", a, b);
NUnit.Framework.Assert.AreEqual(s, expected, result);
}
string s_1 = string.Format("\na = %x\nb = %x\nll= " + ll + "\nbi= " + bi.ToString
(16) + "\n", a, b);
//System.out.println(s);
NUnit.Framework.Assert.AreEqual(s_1, bi, ll.ToBigInteger());
}
/// <summary>Plus equal operation (+=).</summary>
internal virtual LongLong PlusEqual(LongLong that)
{
this.d0 += that.d0;
this.d1 += that.d1;
return(this);
}
