int
mpz_probab_prime_p (mpz_srcptr n, int reps)
{
mp_limb_t r;
mpz_t n2;
/* Handle small and negative n. */
if (mpz_cmp_ui (n, 1000000L) <= 0)
{
if (mpz_cmpabs_ui (n, 1000000L) <= 0)
{
int is_prime;
unsigned long n0;
n0 = mpz_get_ui (n);
is_prime = n0 & (n0 > 1) ? isprime (n0) : n0 == 2;
return is_prime ? 2 : 0;
}
/* Negative number. Negate and fall out. */
PTR(n2) = PTR(n);
SIZ(n2) = -SIZ(n);
n = n2;
}
/* If n is now even, it is not a prime. */
if (mpz_even_p (n))
return 0;
#if defined (PP)
/* Check if n has small factors. */
#if defined (PP_INVERTED)
r = MPN_MOD_OR_PREINV_MOD_1 (PTR(n), (mp_size_t) SIZ(n), (mp_limb_t) PP,
(mp_limb_t) PP_INVERTED);
#else
r = mpn_mod_1 (PTR(n), (mp_size_t) SIZ(n), (mp_limb_t) PP);
#endif
if (r % 3 == 0
#if GMP_LIMB_BITS >= 4
|| r % 5 == 0
#endif
#if GMP_LIMB_BITS >= 8
|| r % 7 == 0
#endif
#if GMP_LIMB_BITS >= 16
|| r % 11 == 0 || r % 13 == 0
#endif
#if GMP_LIMB_BITS >= 32
|| r % 17 == 0 || r % 19 == 0 || r % 23 == 0 || r % 29 == 0
#endif
#if GMP_LIMB_BITS >= 64
|| r % 31 == 0 || r % 37 == 0 || r % 41 == 0 || r % 43 == 0
|| r % 47 == 0 || r % 53 == 0
#endif
)
{
return 0;
}
#endif /* PP */
/* Do more dividing. We collect small primes, using umul_ppmm, until we
overflow a single limb. We divide our number by the small primes product,
and look for factors in the remainder. */
{
unsigned long int ln2;
unsigned long int q;
mp_limb_t p1, p0, p;
unsigned int primes[15];
int nprimes;
nprimes = 0;
p = 1;
ln2 = mpz_sizeinbase (n, 2); /* FIXME: tune this limit */
for (q = PP_FIRST_OMITTED; q < ln2; q += 2)
{
if (isprime (q))
{
umul_ppmm (p1, p0, p, q);
if (p1 != 0)
{
r = MPN_MOD_OR_MODEXACT_1_ODD (PTR(n), (mp_size_t) SIZ(n), p);
while (--nprimes >= 0)
if (r % primes[nprimes] == 0)
{
ASSERT_ALWAYS (mpn_mod_1 (PTR(n), (mp_size_t) SIZ(n), (mp_limb_t) primes[nprimes]) == 0);
return 0;
}
p = q;
nprimes = 0;
}
else
{
p = p0;
}
primes[nprimes++] = q;
}
}
}
/* Perform a number of Miller-Rabin tests. */
return mpz_millerrabin (n, reps);
}
int
mpz_probab_prime_p (mpz_srcptr n, int reps)
{
mp_limb_t r;
/* Handle small and negative n. */
if (mpz_cmp_ui (n, 1000000L) <= 0)
{
int is_prime;
if (mpz_sgn (n) < 0)
{
/* Negative number. Negate and call ourselves. */
mpz_t n2;
mpz_init (n2);
mpz_neg (n2, n);
is_prime = mpz_probab_prime_p (n2, reps);
mpz_clear (n2);
return is_prime;
}
is_prime = isprime (mpz_get_ui (n));
return is_prime ? 2 : 0;
}
/* If n is now even, it is not a prime. */
if ((mpz_get_ui (n) & 1) == 0)
return 0;
#if defined (PP)
/* Check if n has small factors. */
#if defined (PP_INVERTED)
r = MPN_MOD_OR_PREINV_MOD_1 (PTR(n), SIZ(n), (mp_limb_t) PP,
(mp_limb_t) PP_INVERTED);
#else
r = mpn_mod_1 (PTR(n), SIZ(n), (mp_limb_t) PP);
#endif
if (r % 3 == 0
#if BITS_PER_MP_LIMB >= 4
|| r % 5 == 0
#endif
#if BITS_PER_MP_LIMB >= 8
|| r % 7 == 0
#endif
#if BITS_PER_MP_LIMB >= 16
|| r % 11 == 0 || r % 13 == 0
#endif
#if BITS_PER_MP_LIMB >= 32
|| r % 17 == 0 || r % 19 == 0 || r % 23 == 0 || r % 29 == 0
#endif
#if BITS_PER_MP_LIMB >= 64
|| r % 31 == 0 || r % 37 == 0 || r % 41 == 0 || r % 43 == 0
|| r % 47 == 0 || r % 53 == 0
#endif
)
{
return 0;
}
#endif /* PP */
/* Do more dividing. We collect small primes, using umul_ppmm, until we
overflow a single limb. We divide our number by the small primes product,
and look for factors in the remainder. */
{
unsigned long int ln2;
unsigned long int q;
mp_limb_t p1, p0, p;
unsigned int primes[15];
int nprimes;
nprimes = 0;
p = 1;
ln2 = mpz_sizeinbase (n, 2) / 30; ln2 = ln2 * ln2;
for (q = PP_FIRST_OMITTED; q < ln2; q += 2)
{
if (isprime (q))
{
umul_ppmm (p1, p0, p, q);
if (p1 != 0)
{
r = mpn_mod_1 (PTR(n), SIZ(n), p);
while (--nprimes >= 0)
if (r % primes[nprimes] == 0)
{
ASSERT_ALWAYS (mpn_mod_1 (PTR(n), SIZ(n), (mp_limb_t) primes[nprimes]) == 0);
return 0;
}
p = q;
nprimes = 0;
}
else
{
p = p0;
}
primes[nprimes++] = q;
}
}
}
/* Perform a number of Miller-Rabin tests. */
return mpz_millerrabin (n, reps);
}
