int
mpz_perfect_power_p (mpz_srcptr u)
{
unsigned long int prime;
unsigned long int n, n2;
int i;
unsigned long int rem;
mpz_t u2, q;
int exact;
mp_size_t uns;
mp_size_t usize = SIZ (u);
TMP_DECL;
if (mpz_cmpabs_ui (u, 1) <= 0)
return 1; /* -1, 0, and +1 are perfect powers */
n2 = mpz_scan1 (u, 0);
if (n2 == 1)
return 0; /* 2 divides exactly once. */
TMP_MARK;
uns = ABS (usize) - n2 / BITS_PER_MP_LIMB;
MPZ_TMP_INIT (q, uns);
MPZ_TMP_INIT (u2, uns);
mpz_tdiv_q_2exp (u2, u, n2);
mpz_abs (u2, u2);
if (mpz_cmp_ui (u2, 1) == 0)
{
TMP_FREE;
/* factoring completed; consistent power */
return ! (usize < 0 && POW2P(n2));
}
if (isprime (n2))
goto n2prime;
for (i = 1; primes[i] != 0; i++)
{
prime = primes[i];
if (mpz_cmp_ui (u2, prime) < 0)
break;
if (mpz_divisible_ui_p (u2, prime)) /* divisible by this prime? */
{
rem = mpz_tdiv_q_ui (q, u2, prime * prime);
if (rem != 0)
{
TMP_FREE;
return 0; /* prime divides exactly once, reject */
}
mpz_swap (q, u2);
for (n = 2;;)
{
rem = mpz_tdiv_q_ui (q, u2, prime);
if (rem != 0)
break;
mpz_swap (q, u2);
n++;
}
n2 = gcd (n2, n);
if (n2 == 1)
{
TMP_FREE;
return 0; /* we have multiplicity 1 of some factor */
}
if (mpz_cmp_ui (u2, 1) == 0)
{
TMP_FREE;
/* factoring completed; consistent power */
return ! (usize < 0 && POW2P(n2));
}
/* As soon as n2 becomes a prime number, stop factoring.
Either we have u=x^n2 or u is not a perfect power. */
if (isprime (n2))
goto n2prime;
}
}
if (n2 == 0)
{
/* We found no factors above; have to check all values of n. */
unsigned long int nth;
for (nth = usize < 0 ? 3 : 2;; nth++)
{
if (! isprime (nth))
continue;
#if 0
exact = mpz_padic_root (q, u2, nth, PTH);
if (exact)
#endif
exact = mpz_root (q, u2, nth);
if (exact)
{
TMP_FREE;
return 1;
}
if (mpz_cmp_ui (q, SMALLEST_OMITTED_PRIME) < 0)
{
TMP_FREE;
return 0;
}
}
}
else
{
unsigned long int nth;
if (usize < 0 && POW2P(n2))
{
TMP_FREE;
return 0;
}
/* We found some factors above. We just need to consider values of n
that divides n2. */
for (nth = 2; nth <= n2; nth++)
{
if (! isprime (nth))
continue;
if (n2 % nth != 0)
continue;
#if 0
exact = mpz_padic_root (q, u2, nth, PTH);
if (exact)
#endif
exact = mpz_root (q, u2, nth);
if (exact)
{
if (! (usize < 0 && POW2P(nth)))
{
TMP_FREE;
return 1;
}
}
if (mpz_cmp_ui (q, SMALLEST_OMITTED_PRIME) < 0)
{
TMP_FREE;
return 0;
}
}
TMP_FREE;
return 0;
}
n2prime:
if (usize < 0 && POW2P(n2))
{
TMP_FREE;
return 0;
}
exact = mpz_root (NULL, u2, n2);
TMP_FREE;
return exact;
}
/* TRUE if radix-r is ugly for size n */
int X(ct_uglyp)(INT min_n, INT v, INT n, INT r)
{
return (n <= min_n) || (POW2P(n) && (v * (n / r)) <= 4);
}
/* TRUE if radix-r is ugly for size n */
int fftwf_ct_uglyp(INT min_n, INT v, INT n, INT r)
{
return (n <= min_n) || (POW2P(n) && (v * (n / r)) <= 4);
}
