/* this-=Q */
public void Sub(ECP Q)
{
ECP NQ = new ECP(Q);
NQ.Neg();
Add(NQ);
}
/* Constant time select from pre-computed table */
private void Select(ECP[] W, int b)
{
ECP MP = new ECP();
int m = b >> 31;
int babs = (b ^ m) - m;
babs = (babs - 1) / 2;
CMove(W[0], Teq(babs, 0)); // conditional move
CMove(W[1], Teq(babs, 1));
CMove(W[2], Teq(babs, 2));
CMove(W[3], Teq(babs, 3));
CMove(W[4], Teq(babs, 4));
CMove(W[5], Teq(babs, 5));
CMove(W[6], Teq(babs, 6));
CMove(W[7], Teq(babs, 7));
MP.Copy(this);
MP.Neg();
CMove(MP, (int)(m & 1));
}
