// x = x/R mod m (HAC 14.32)
public void reduce(BigInteger x)
{
if (x == null)
{
return;
}
while (x.t <= this.mt2)
{
// pad x so am has enough room later
x.SetData(x.t++, 0);
}
for (int i = 0; i < this.m.t; ++i)
{
// faster way of calculating u0 = x[i]*mp mod DV
int j = x.datas[i] & 0x7fff;
int u0 = (j * this.mpl + (((j * this.mph + (x.datas[i] >> 15) * this.mpl) & this.um) << 15))
& x.DM;
// use am to combine the multiply-shift-add into one call
j = i + this.m.t;
x.datas[j] += this.m.am(0, u0, x.datas, i, 0, this.m.t);
// propagate carry
while (x.datas[j] >= x.DV)
{
x.datas[j] -= x.DV;
x.datas[++j]++;
}
}
x.clamp();
x.drShiftTo(this.m.t, x);
if (x.compareTo(this.m) >= 0)
{
x.subTo(this.m, x);
}
}
// (public) this mod a
public BigInteger mod(BigInteger a)
{
BigInteger r = new BigInteger();
this.abs().divRemTo(a, null, r);
if (this.s < 0 && r.compareTo(ZERO) > 0)
{
a.subTo(r, r);
}
return r;
}