CunninghamLengths PrimeTester::ProbablePrimeChainTest(const Bn& origin, PrimeChainType chainType) {
CunninghamLengths r;
Bn t(origin);
switch (chainType) {
case PrimeChainType::Cunningham1:
r.Cunningham1Length = ProbableCunninghamChainTest(t -= 1, 1);
break;
case PrimeChainType::Cunningham2:
r.Cunningham2Length = ProbableCunninghamChainTest(t += 1, -1);
break;
case PrimeChainType::Twin:
if ((r.Cunningham1Length = ProbableCunninghamChainTest(t -= 1, 1)) >= 1) {
r.Cunningham2Length = ProbableCunninghamChainTest(t += 2, -1);
r.TwinLength = floor(r.Cunningham1Length) > floor(r.Cunningham2Length)
? r.Cunningham2Length + 1 + floor(r.Cunningham2Length)
: r.Cunningham1Length + floor(r.Cunningham1Length);
}
break;
default:
r.Cunningham1Length = ProbableCunninghamChainTest(t -= 1, 1);
r.Cunningham2Length = ProbableCunninghamChainTest(t += 2, -1);
r.TwinLength = floor(r.Cunningham1Length) > floor(r.Cunningham2Length)
? r.Cunningham2Length + 1 + floor(r.Cunningham2Length)
: r.Cunningham1Length + floor(r.Cunningham1Length);
}
return r;
}
int ChainTest(int ChainType, vec_uint4 n[3], int *chainLength)
{
if (ChainType == CHAINTYPE_CC1)
{
return ProbableCunninghamChainTest(n, 1, 0, chainLength);
}
else if (ChainType == CHAINTYPE_CC2)
{
return ProbableCunninghamChainTest(n, 0, 0, chainLength);
}
else if (ChainType == CHAINTYPE_TWN)
{
vec_uint4 n2[3];
n2[0] = n[0];
n2[1] = n[1];
n2[2] = n[2];
int c1=0;
int c2=0;
if (ProbableCunninghamChainTest(n, 1, 0, &c1))
{
if (ProbableCunninghamChainTest(n2, 0, 0, &c2))
{
if (c1 > c2) *chainLength = c2+c2+1;
else *chainLength = c1+c1;
// printf("TWN: %d + %d = %d\n", c1, c2, *chainLength);
return 1;
}
}
}
return 0;
}