void
fmpr_divappr_abs_ubound(fmpr_t z, const fmpr_t x, const fmpr_t y, slong prec)
{
if (fmpr_is_special(x) || fmpr_is_special(y) || fmpz_is_pm1(fmpr_manref(y)))
{
fmpr_div(z, x, y, prec, FMPR_RND_UP);
fmpr_abs(z, z);
}
else
{
fmpz_t t, u;
slong xbits, ybits, tbits, ubits, shift;
xbits = fmpz_bits(fmpr_manref(x));
ybits = fmpz_bits(fmpr_manref(y));
fmpz_init(t);
fmpz_init(u);
ubits = FLINT_MIN(ybits, prec);
tbits = prec + ubits + 1;
/* upper bound for |x|, shifted */
if (xbits <= tbits)
{
fmpz_mul_2exp(t, fmpr_manref(x), tbits - xbits);
fmpz_abs(t, t);
}
else if (fmpz_sgn(fmpr_manref(x)) > 0)
{
fmpz_cdiv_q_2exp(t, fmpr_manref(x), xbits - tbits);
}
else
{
fmpz_fdiv_q_2exp(t, fmpr_manref(x), xbits - tbits);
fmpz_neg(t, t);
}
/* lower bound for |y|, shifted */
if (ybits <= ubits)
fmpz_mul_2exp(u, fmpr_manref(y), ubits - ybits);
else
fmpz_tdiv_q_2exp(u, fmpr_manref(y), ybits - ubits);
fmpz_abs(u, u);
fmpz_cdiv_q(fmpr_manref(z), t, u);
shift = (ubits - ybits) - (tbits - xbits);
fmpz_sub(fmpr_expref(z), fmpr_expref(x), fmpr_expref(y));
if (shift >= 0)
fmpz_add_ui(fmpr_expref(z), fmpr_expref(z), shift);
else
fmpz_sub_ui(fmpr_expref(z), fmpr_expref(z), -shift);
_fmpr_normalise(fmpr_manref(z), fmpr_expref(z), prec, FMPR_RND_UP);
fmpz_clear(t);
fmpz_clear(u);
}
}
/* quotient of absolute value, rounded up */
static __inline__ void
fmpz_cdiv_abs_q(fmpz_t q, const fmpz_t x, const fmpz_t y)
{
if (fmpz_sgn(x) == fmpz_sgn(y))
{
fmpz_cdiv_q(q, x, y);
}
else
{
fmpz_fdiv_q(q, x, y);
fmpz_neg(q, q);
}
}
int
main(void)
{
int i, result;
FLINT_TEST_INIT(state);
flint_printf("cdiv_q....");
fflush(stdout);
for (i = 0; i < 10000 * flint_test_multiplier(); i++)
{
fmpz_t a, b, c;
mpz_t d, e, f, g;
fmpz_init(a);
fmpz_init(b);
fmpz_init(c);
mpz_init(d);
mpz_init(e);
mpz_init(f);
mpz_init(g);
fmpz_randtest(a, state, 200);
fmpz_randtest_not_zero(b, state, 200);
fmpz_get_mpz(d, a);
fmpz_get_mpz(e, b);
fmpz_cdiv_q(c, a, b);
mpz_cdiv_q(f, d, e);
fmpz_get_mpz(g, c);
result = (mpz_cmp(f, g) == 0);
if (!result)
{
flint_printf("FAIL\n");
gmp_printf("d = %Zd, e = %Zd, f = %Zd, g = %Zd\n", d, e, f, g);
abort();
}
fmpz_clear(a);
fmpz_clear(b);
fmpz_clear(c);
mpz_clear(d);
mpz_clear(e);
mpz_clear(f);
mpz_clear(g);
}
/* Check aliasing of a and b */
for (i = 0; i < 10000 * flint_test_multiplier(); i++)
{
fmpz_t a, c;
mpz_t d, f, g;
fmpz_init(a);
fmpz_init(c);
mpz_init(d);
mpz_init(f);
mpz_init(g);
fmpz_randtest_not_zero(a, state, 200);
fmpz_get_mpz(d, a);
fmpz_cdiv_q(c, a, a);
mpz_cdiv_q(f, d, d);
fmpz_get_mpz(g, c);
result = (mpz_cmp(f, g) == 0);
if (!result)
{
flint_printf("FAIL\n");
gmp_printf("d = %Zd, f = %Zd, g = %Zd\n", d, f, g);
abort();
}
fmpz_clear(a);
fmpz_clear(c);
mpz_clear(d);
mpz_clear(f);
mpz_clear(g);
}
/* Test aliasing of a and c */
for (i = 0; i < 10000 * flint_test_multiplier(); i++)
{
fmpz_t a, b;
mpz_t d, e, f, g;
fmpz_init(a);
fmpz_init(b);
mpz_init(d);
mpz_init(e);
mpz_init(f);
mpz_init(g);
fmpz_randtest(a, state, 200);
fmpz_randtest_not_zero(b, state, 200);
fmpz_get_mpz(d, a);
fmpz_get_mpz(e, b);
fmpz_cdiv_q(a, a, b);
mpz_cdiv_q(f, d, e);
fmpz_get_mpz(g, a);
result = (mpz_cmp(f, g) == 0);
if (!result)
{
flint_printf("FAIL\n");
gmp_printf("d = %Zd, e = %Zd, f = %Zd, g = %Zd\n", d, e, f, g);
abort();
}
fmpz_clear(a);
fmpz_clear(b);
mpz_clear(d);
mpz_clear(e);
mpz_clear(f);
mpz_clear(g);
}
/* Test aliasing of b and c */
for (i = 0; i < 10000 * flint_test_multiplier(); i++)
{
fmpz_t a, b;
mpz_t d, e, f, g;
fmpz_init(a);
fmpz_init(b);
mpz_init(d);
mpz_init(e);
mpz_init(f);
mpz_init(g);
fmpz_randtest(a, state, 200);
fmpz_randtest_not_zero(b, state, 200);
fmpz_get_mpz(d, a);
fmpz_get_mpz(e, b);
fmpz_cdiv_q(b, a, b);
mpz_cdiv_q(f, d, e);
fmpz_get_mpz(g, b);
result = (mpz_cmp(f, g) == 0);
if (!result)
{
flint_printf("FAIL\n");
gmp_printf("d = %Zd, e = %Zd, f = %Zd, g = %Zd\n", d, e, f, g);
abort();
}
fmpz_clear(a);
fmpz_clear(b);
mpz_clear(d);
mpz_clear(e);
mpz_clear(f);
mpz_clear(g);
}
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return 0;
}
