void fmpz_poly_q_canonicalise(fmpz_poly_q_t rop)
{
fmpz_poly_t gcd;
if (fmpz_poly_is_zero(rop->den))
{
flint_printf("Exception (fmpz_poly_q_canonicalise). Denominator is zero.\n");
abort();
}
if (fmpz_poly_is_one(rop->den))
return;
fmpz_poly_init(gcd);
fmpz_poly_gcd(gcd, rop->num, rop->den);
if (!fmpz_poly_is_unit(gcd))
{
fmpz_poly_div(rop->num, rop->num, gcd);
fmpz_poly_div(rop->den, rop->den, gcd);
}
fmpz_poly_clear(gcd);
if (fmpz_sgn(fmpz_poly_lead(rop->den)) < 0)
{
fmpz_poly_neg(rop->num, rop->num);
fmpz_poly_neg(rop->den, rop->den);
}
}
void fmpz_poly_q_mul(fmpz_poly_q_t rop,
const fmpz_poly_q_t op1, const fmpz_poly_q_t op2)
{
if (fmpz_poly_q_is_zero(op1) || fmpz_poly_q_is_zero(op2))
{
fmpz_poly_q_zero(rop);
return;
}
if (op1 == op2)
{
fmpz_poly_pow(rop->num, op1->num, 2);
fmpz_poly_pow(rop->den, op1->den, 2);
return;
}
if (rop == op1 || rop == op2)
{
fmpz_poly_q_t t;
fmpz_poly_q_init(t);
fmpz_poly_q_mul(t, op1, op2);
fmpz_poly_q_swap(rop, t);
fmpz_poly_q_clear(t);
return;
}
/*
From here on, we may assume that rop, op1 and op2 refer to distinct
objects in memory, and that op1 and op2 are non-zero
*/
/* Polynomials? */
if (fmpz_poly_length(op1->den) == 1 && fmpz_poly_length(op2->den) == 1)
{
const slong len1 = fmpz_poly_length(op1->num);
const slong len2 = fmpz_poly_length(op2->num);
fmpz_poly_fit_length(rop->num, len1 + len2 - 1);
if (len1 >= len2)
{
_fmpq_poly_mul(rop->num->coeffs, rop->den->coeffs,
op1->num->coeffs, op1->den->coeffs, len1,
op2->num->coeffs, op2->den->coeffs, len2);
}
else
{
_fmpq_poly_mul(rop->num->coeffs, rop->den->coeffs,
op2->num->coeffs, op2->den->coeffs, len2,
op1->num->coeffs, op1->den->coeffs, len1);
}
_fmpz_poly_set_length(rop->num, len1 + len2 - 1);
_fmpz_poly_set_length(rop->den, 1);
return;
}
fmpz_poly_gcd(rop->num, op1->num, op2->den);
if (fmpz_poly_is_one(rop->num))
{
fmpz_poly_gcd(rop->den, op2->num, op1->den);
if (fmpz_poly_is_one(rop->den))
{
fmpz_poly_mul(rop->num, op1->num, op2->num);
fmpz_poly_mul(rop->den, op1->den, op2->den);
}
else
{
fmpz_poly_div(rop->num, op2->num, rop->den);
fmpz_poly_mul(rop->num, op1->num, rop->num);
fmpz_poly_div(rop->den, op1->den, rop->den);
fmpz_poly_mul(rop->den, rop->den, op2->den);
}
}
else
{
fmpz_poly_gcd(rop->den, op2->num, op1->den);
if (fmpz_poly_is_one(rop->den))
{
fmpz_poly_div(rop->den, op2->den, rop->num);
fmpz_poly_mul(rop->den, op1->den, rop->den);
fmpz_poly_div(rop->num, op1->num, rop->num);
fmpz_poly_mul(rop->num, rop->num, op2->num);
}
else
{
fmpz_poly_t t, u;
fmpz_poly_init(t);
fmpz_poly_init(u);
fmpz_poly_div(t, op1->num, rop->num);
fmpz_poly_div(u, op2->den, rop->num);
fmpz_poly_div(rop->num, op2->num, rop->den);
fmpz_poly_mul(rop->num, t, rop->num);
fmpz_poly_div(rop->den, op1->den, rop->den);
fmpz_poly_mul(rop->den, rop->den, u);
fmpz_poly_clear(t);
fmpz_poly_clear(u);
}
}
}
int
main(void)
{
int i, result;
flint_rand_t state;
printf("gcd....");
fflush(stdout);
flint_randinit(state);
/* Check aliasing of a and b */
for (i = 0; i < 500; i++)
{
fmpz_poly_t a, b, c;
fmpz_poly_init(a);
fmpz_poly_init(b);
fmpz_poly_init(c);
fmpz_poly_randtest(b, state, n_randint(state, 40), 80);
fmpz_poly_randtest(c, state, n_randint(state, 40), 80);
fmpz_poly_gcd(a, b, c);
fmpz_poly_gcd(b, b, c);
result = (fmpz_poly_equal(a, b));
if (!result)
{
printf("FAIL (aliasing a and b):\n");
fmpz_poly_print(a), printf("\n\n");
fmpz_poly_print(b), printf("\n\n");
abort();
}
fmpz_poly_clear(a);
fmpz_poly_clear(b);
fmpz_poly_clear(c);
}
/* Check aliasing of a and c */
for (i = 0; i < 500; i++)
{
fmpz_poly_t a, b, c;
fmpz_poly_init(a);
fmpz_poly_init(b);
fmpz_poly_init(c);
fmpz_poly_randtest(b, state, n_randint(state, 40), 80);
fmpz_poly_randtest(c, state, n_randint(state, 40), 80);
fmpz_poly_gcd(a, b, c);
fmpz_poly_gcd(c, b, c);
result = (fmpz_poly_equal(a, c));
if (!result)
{
printf("FAIL (aliasing a and c):\n");
fmpz_poly_print(a), printf("\n\n");
fmpz_poly_print(c), printf("\n\n");
abort();
}
fmpz_poly_clear(a);
fmpz_poly_clear(b);
fmpz_poly_clear(c);
}
/* Check that a divides GCD(af, ag) */
for (i = 0; i < 500; i++)
{
fmpz_poly_t a, d, f, g, q, r;
fmpz_poly_init(a);
fmpz_poly_init(d);
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_init(q);
fmpz_poly_init(r);
fmpz_poly_randtest_not_zero(a, state, n_randint(state, 24) + 1, 24);
fmpz_poly_randtest(f, state, n_randint(state, 40), 80);
fmpz_poly_randtest(g, state, n_randint(state, 40), 80);
fmpz_poly_mul(f, a, f);
fmpz_poly_mul(g, a, g);
fmpz_poly_gcd(d, f, g);
fmpz_poly_divrem_divconquer(q, r, d, a);
result = (r->length == 0L);
if (!result)
{
printf("FAIL (check a | gcd(af, ag)):\n");
fmpz_poly_print(f), printf("\n");
fmpz_poly_print(g), printf("\n");
fmpz_poly_print(d), printf("\n");
abort();
}
fmpz_poly_clear(a);
fmpz_poly_clear(d);
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_poly_clear(q);
fmpz_poly_clear(r);
}
flint_randclear(state);
_fmpz_cleanup();
printf("PASS\n");
return 0;
}
