void _fmpq_poly_set_length(fmpq_poly_t poly, long len)
{
long i;
for (i = len; i < poly->length; i++)
_fmpz_demote(poly->coeffs + i);
poly->length = len;
}
void fmpq_poly_clear(fmpq_poly_t poly)
{
if (poly->coeffs)
{
slong i;
for (i = 0; i < poly->alloc; i++)
_fmpz_demote(poly->coeffs + i);
flint_free(poly->coeffs);
}
fmpz_clear(poly->den);
}
void
fmpz_set(fmpz_t f, const fmpz_t g)
{
if (f == g)
return; /* aliased inputs */
if (!COEFF_IS_MPZ(*g)) /* g is small */
{
_fmpz_demote(f);
*f = *g;
}
else /* g is large */
{
__mpz_struct *mpz_ptr = _fmpz_promote(f);
mpz_set(mpz_ptr, COEFF_TO_PTR(*g));
}
}
void
mag_set_d_lower(mag_t z, double c)
{
if (c < 0.0)
c = -c;
if (c == 0.0 || (c != c))
{
mag_zero(z);
}
else if (c == D_INF)
{
mag_inf(z);
}
else
{
_fmpz_demote(MAG_EXPREF(z));
MAG_SET_D_2EXP_LOWER(MAG_MAN(z), MAG_EXP(z), c, 0);
}
}
void
mag_rfac_ui(mag_t z, ulong n)
{
if (n < MAG_FAC_TABLE_NUM)
{
_fmpz_demote(MAG_EXPREF(z));
MAG_EXP(z) = mag_rfac_tab[n * 2];
MAG_MAN(z) = mag_rfac_tab[n * 2 + 1];
}
else
{
double x = n;
x = ceil((((x+0.5)*mag_d_log_lower_bound(x) - x) * 1.4426950408889634074) * -0.9999999);
/* x + 1 could round down for huge x, but this doesn't matter
as long as the value was perturbed up above */
fmpz_set_d(MAG_EXPREF(z), x + 1);
MAG_MAN(z) = MAG_ONE_HALF;
}
}
void
fmpz_randtest_unsigned(fmpz_t f, flint_rand_t state, mp_bitcnt_t bits)
{
ulong m;
m = n_randlimb(state);
bits = n_randint(state, bits + 1);
if (bits <= FLINT_BITS - 2)
{
_fmpz_demote(f);
if (m & UWORD(3))
*f = n_randtest_bits(state, bits);
else
{
m >>= 2;
if (bits == 0)
*f = 0;
else if (bits < FLINT_BITS - 2)
*f = m & UWORD(1);
else
*f = COEFF_MAX;
}
}
void fmpz_powm_ui(fmpz_t f, const fmpz_t g, ulong e, const fmpz_t m)
{
if (fmpz_sgn(m) <= 0)
{
printf("Exception (fmpz_powm_ui). Modulus is less than 1.\n");
abort();
}
if (fmpz_is_one(m))
{
fmpz_zero(f);
}
else if (e == 0)
{
fmpz_one(f);
}
else /* e != 0, m > 0 */
{
fmpz g2 = *g;
fmpz m2 = *m;
if (!COEFF_IS_MPZ(m2)) /* m is small */
{
if (!COEFF_IS_MPZ(g2)) /* g is small */
{
mp_limb_t minv = n_preinvert_limb(m2);
_fmpz_demote(f);
if (g2 >= 0)
{
g2 = n_mod2_preinv(g2, m2, minv);
*f = n_powmod2_preinv(g2, e, m2, minv);
}
else
{
g2 = n_mod2_preinv(-g2, m2, minv);
*f = n_powmod2_preinv(g2, e, m2, minv);
if ((e & 1UL))
*f = n_negmod(*f, m2);
}
}
else /* g is large */
{
__mpz_struct *ptr = _fmpz_promote(f);
mpz_t m3;
mpz_init_set_ui(m3, m2);
mpz_powm_ui(ptr, COEFF_TO_PTR(g2), e, m3);
mpz_clear(m3);
_fmpz_demote_val(f);
}
}
else /* m is large */
{
if (!COEFF_IS_MPZ(g2)) /* g is small */
{
__mpz_struct *ptr = _fmpz_promote(f);
mpz_t g3;
mpz_init_set_si(g3, g2);
mpz_powm_ui(ptr, g3, e, COEFF_TO_PTR(m2));
mpz_clear(g3);
_fmpz_demote_val(f);
}
else /* g is large */
{
__mpz_struct *ptr = _fmpz_promote(f);
mpz_powm_ui(ptr, COEFF_TO_PTR(g2), e, COEFF_TO_PTR(m2));
_fmpz_demote_val(f);
}
}
}
}
