/* Check that hardware rounding doesn't make mpz_get_d_2exp return a value
outside its defined range. */
static void
check_round (void)
{
static const unsigned long data[] = { 1, 32, 53, 54, 64, 128, 256, 512 };
mpz_t z;
double got;
long got_exp;
int i, rnd_mode, old_rnd_mode;
mpz_init (z);
old_rnd_mode = tests_hardware_getround ();
for (rnd_mode = 0; rnd_mode < 4; rnd_mode++)
{
tests_hardware_setround (rnd_mode);
for (i = 0; i < numberof (data); i++)
{
mpz_set_ui (z, 1L);
mpz_mul_2exp (z, z, data[i]);
mpz_sub_ui (z, z, 1L);
got = mpz_get_d_2exp (&got_exp, z);
if (got < 0.5 || got >= 1.0)
{
printf ("mpz_get_d_2exp wrong on 2**%lu-1\n", data[i]);
printf ("result out of range, expect 0.5 <= got < 1.0\n");
printf (" rnd_mode = %d\n", rnd_mode);
printf (" data[i] = %lu\n", data[i]);
mpz_trace (" z ", z);
d_trace (" got ", got);
printf (" got exp %ld\n", got_exp);
abort();
}
mpz_neg (z, z);
got = mpz_get_d_2exp (&got_exp, z);
if (got <= -1.0 || got > -0.5)
{
printf ("mpz_get_d_2exp wrong on -2**%lu-1\n", data[i]);
printf ("result out of range, expect -1.0 < got <= -0.5\n");
printf (" rnd_mode = %d\n", rnd_mode);
printf (" data[i] = %lu\n", data[i]);
mpz_trace (" z ", z);
d_trace (" got ", got);
printf (" got exp %ld\n", got_exp);
abort();
}
}
}
mpz_clear (z);
tests_hardware_setround (old_rnd_mode);
}
static void
check_onebit (void)
{
static const unsigned long data[] = {
1, 32, 52, 53, 54, 63, 64, 65, 128, 256, 511, 512, 513
};
mpz_t z;
double got, want;
long got_exp, want_exp;
int i;
mpz_init (z);
for (i = 0; i < numberof (data); i++)
{
mpz_set_ui (z, 1L);
mpz_mul_2exp (z, z, data[i]);
want = 0.5;
want_exp = data[i] + 1;
got = mpz_get_d_2exp (&got_exp, z);
if (got != want || got_exp != want_exp)
{
printf ("mpz_get_d_2exp wrong on 2**%ld\n", data[i]);
mpz_trace (" z ", z);
d_trace (" want ", want);
d_trace (" got ", got);
printf (" want exp %ld\n", want_exp);
printf (" got exp %ld\n", got_exp);
abort();
}
mpz_set_si (z, -1L);
mpz_mul_2exp (z, z, data[i]);
want = -0.5;
want_exp = data[i] + 1;
got = mpz_get_d_2exp (&got_exp, z);
if (got != want || got_exp != want_exp)
{
printf ("mpz_get_d_2exp wrong on -2**%ld\n", data[i]);
mpz_trace (" z ", z);
d_trace (" want ", want);
d_trace (" got ", got);
printf (" want exp %ld\n", want_exp);
printf (" got exp %ld\n", got_exp);
abort();
}
}
mpz_clear (z);
}
/* rslt is always integral due to ceiling operation */
void
mpz_logbase2cl (sli_t * rslt, mpz_t n)
{
if (mpz_get_d_2exp (rslt, n) == 0.5)
{
--(*rslt);
}
}
double
fmpz_dlog(const fmpz_t x)
{
if (!COEFF_IS_MPZ(*x))
{
return log(*x);
}
else
{
double s;
slong e;
#if defined(__MPIR_VERSION)
s = mpz_get_d_2exp(&e, COEFF_TO_PTR(*x));
#else
s = mpz_get_d_2exp((long *) &e, COEFF_TO_PTR(*x));
#endif
return log(s) + e * 0.69314718055994530942;
}
}
static void
check_rand (void)
{
gmp_randstate_ptr rands = RANDS;
int i;
mpz_t z;
double got;
long got_exp;
unsigned long bits;
mpz_init (z);
for (i = 0; i < 200; i++)
{
bits = gmp_urandomm_ui (rands, 512L);
mpz_urandomb (z, rands, bits);
got = mpz_get_d_2exp (&got_exp, z);
if (mpz_sgn (z) == 0)
continue;
bits = mpz_sizeinbase (z, 2);
if (got < 0.5 || got >= 1.0)
{
printf ("mpz_get_d_2exp out of range, expect 0.5 <= got < 1.0\n");
mpz_trace (" z ", z);
d_trace (" got ", got);
printf (" got exp %ld\n", got_exp);
abort();
}
/* FIXME: If mpz_get_d_2exp rounds upwards we might have got_exp ==
bits+1, so leave this test disabled until we decide if that's what
should happen, or not. */
#if 0
if (got_exp != bits)
{
printf ("mpz_get_d_2exp wrong exponent\n", i);
mpz_trace (" z ", z);
d_trace (" bits ", bits);
d_trace (" got ", got);
printf (" got exp %ld\n", got_exp);
abort();
}
#endif
}
mpz_clear (z);
}
/* Convert bignum to a `double`, truncating if necessary
* (i.e. rounding towards zero).
*
* sign of mp_size_t argument controls sign of converted double
*/
HsDouble
integer_gmp_mpn_get_d (const mp_limb_t sp[], const mp_size_t sn,
const HsInt exponent)
{
if (mp_limb_zero_p(sp, sn))
return 0.0;
const mpz_t mpz = CONST_MPZ_INIT(sp, sn);
if (!exponent)
return mpz_get_d(mpz);
long e = 0;
double d = mpz_get_d_2exp (&e, mpz);
// TODO: over/underflow handling?
return ldexp(d, e+exponent);
}