Exemplo n.º 1
0
void subg(giant a, giant b)
/* b := b - a, any signs, any result. */
{
	int 		asgn = a->sign, bsgn = b->sign;

	if (asgn == 0)
		return;
	if (bsgn == 0)
	{
		gtog(a, b);
		negg(b);
		return;
	}
	if ((asgn < 0) != (bsgn < 0))
	{
		if (bsgn > 0)
		{
			negg(a);
			normal_addg(a, b);
			negg(a);
			return;
		}
		negg(b);
		normal_addg(a, b);
		negg(b);
		return;
	}
	if (bsgn > 0)
	{
		if (gcompg(b, a) >= 0)
		{
			normal_subg(a, b);
			return;
		}
		reverse_subg(a, b);
		negg(b);
		return;
	}
	negg(a);
	negg(b);
	if (gcompg(b, a) >= 0)
	{
		normal_subg(a, b);
		negg(a);
		negg(b);
		return;
	}
	reverse_subg(a, b);
	negg(a);
	return;
}
Exemplo n.º 2
0
void addg(giant a, giant b)
/* b := b + a, any signs any result. */
{   int asgn = a->sign, bsgn = b->sign;
    if(asgn == 0) return;
    if(bsgn == 0) {
    	gtog(a,b);
	return;
    }
    if((asgn < 0) == (bsgn < 0)) {
    	if(bsgn > 0) {
		normal_addg(a,b);
		return;
	}
	negg(a); if(a != b) negg(b); normal_addg(a,b);  /* Fix REC 1 Dec 98. */
	negg(a); if(a != b) negg(b); return;  /* Fix REC 1 Dec 98. */
    }
    if(bsgn > 0) {
        negg(a);
	if(gcompg(b,a) >= 0) {
		normal_subg(a,b);
		negg(a);
		return;
	}
	reverse_subg(a,b);
	negg(a);
	negg(b);
	return;
    }
    negg(b);
    if(gcompg(b,a) < 0) {
    	reverse_subg(a,b);
	return;
    }
    normal_subg(a,b);
    negg(b);
    return;
}