/* Test mpn_get_d.
Copyright 2002-2004 Free Software Foundation, Inc.
This file is part of the GNU MP Library test suite.
The GNU MP Library test suite is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of the License,
or (at your option) any later version.
The GNU MP Library test suite is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.
You should have received a copy of the GNU General Public License along with
the GNU MP Library test suite. If not, see https://www.gnu.org/licenses/. */
#include "config.h"
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include "gmp.h"
#include "gmp-impl.h"
#include "tests.h"
#ifndef _GMP_IEEE_FLOATS
#define _GMP_IEEE_FLOATS 0
#endif
/* Exercise various 2^n values, with various exponents and positive and
negative. */
void
check_onebit (void)
{
static const int bit_table[] = {
0, 1, 2, 3,
GMP_NUMB_BITS - 2, GMP_NUMB_BITS - 1,
GMP_NUMB_BITS,
GMP_NUMB_BITS + 1, GMP_NUMB_BITS + 2,
2 * GMP_NUMB_BITS - 2, 2 * GMP_NUMB_BITS - 1,
2 * GMP_NUMB_BITS,
2 * GMP_NUMB_BITS + 1, 2 * GMP_NUMB_BITS + 2,
3 * GMP_NUMB_BITS - 2, 3 * GMP_NUMB_BITS - 1,
3 * GMP_NUMB_BITS,
3 * GMP_NUMB_BITS + 1, 3 * GMP_NUMB_BITS + 2,
4 * GMP_NUMB_BITS - 2, 4 * GMP_NUMB_BITS - 1,
4 * GMP_NUMB_BITS,
4 * GMP_NUMB_BITS + 1, 4 * GMP_NUMB_BITS + 2,
5 * GMP_NUMB_BITS - 2, 5 * GMP_NUMB_BITS - 1,
5 * GMP_NUMB_BITS,
5 * GMP_NUMB_BITS + 1, 5 * GMP_NUMB_BITS + 2,
6 * GMP_NUMB_BITS - 2, 6 * GMP_NUMB_BITS - 1,
6 * GMP_NUMB_BITS,
6 * GMP_NUMB_BITS + 1, 6 * GMP_NUMB_BITS + 2,
};
static const int exp_table[] = {
0, -100, -10, -1, 1, 10, 100,
};
/* FIXME: It'd be better to base this on the float format. */
#if defined (__vax) || defined (__vax__)
int limit = 127; /* vax fp numbers have limited range */
#else
int limit = 511;
#endif
int bit_i, exp_i, i;
double got, want;
mp_size_t nsize, sign;
long bit, exp, want_bit;
mp_limb_t np[20];
for (bit_i = 0; bit_i < numberof (bit_table); bit_i++)
{
bit = bit_table[bit_i];
nsize = BITS_TO_LIMBS (bit+1);
refmpn_zero (np, nsize);
np[bit/GMP_NUMB_BITS] = CNST_LIMB(1) << (bit % GMP_NUMB_BITS);
for (exp_i = 0; exp_i < numberof (exp_table); exp_i++)
{
exp = exp_table[exp_i];
want_bit = bit + exp;
if (want_bit >= limit || want_bit <= -limit)
continue;
want = 1.0;
for (i = 0; i < want_bit; i++)
want *= 2.0;
for (i = 0; i > want_bit; i--)
want *= 0.5;
for (sign = 0; sign >= -1; sign--, want = -want)
{
got = mpn_get_d (np, nsize, sign, exp);
if (got != want)
{
printf ("mpn_get_d wrong on 2^n\n");
printf (" bit %ld\n", bit);
printf (" exp %ld\n", exp);
printf (" want_bit %ld\n", want_bit);
printf (" sign %ld\n", (long) sign);
mpn_trace (" n ", np, nsize);
printf (" nsize %ld\n", (long) nsize);
d_trace (" want ", want);
d_trace (" got ", got);
abort();
}
}
}
}
}
/* Exercise values 2^n+1, while such a value fits the mantissa of a double. */
void
check_twobit (void)
{
int i, mant_bits;
double got, want;
mp_size_t nsize, sign;
mp_ptr np;
mant_bits = tests_dbl_mant_bits ();
if (mant_bits == 0)
return;
np = refmpn_malloc_limbs (BITS_TO_LIMBS (mant_bits));
want = 3.0;
for (i = 1; i < mant_bits; i++)
{
nsize = BITS_TO_LIMBS (i+1);
refmpn_zero (np, nsize);
np[i/GMP_NUMB_BITS] = CNST_LIMB(1) << (i % GMP_NUMB_BITS);
np[0] |= 1;
for (sign = 0; sign >= -1; sign--)
{
got = mpn_get_d (np, nsize, sign, 0);
if (got != want)
{
printf ("mpn_get_d wrong on 2^%d + 1\n", i);
printf (" sign %ld\n", (long) sign);
mpn_trace (" n ", np, nsize);
printf (" nsize %ld\n", (long) nsize);
d_trace (" want ", want);
d_trace (" got ", got);
abort();
}
want = -want;
}
want = 2.0 * want - 1.0;
}
free (np);
}
/* Expect large negative exponents to underflow to 0.0.
Some systems might have hardware traps for such an underflow (though
usually it's not the default), so watch out for SIGFPE. */
void
check_underflow (void)
{
static const long exp_table[] = {
-999999L, LONG_MIN,
};
static const mp_limb_t np[1] = { 1 };
static long exp;
mp_size_t nsize, sign;
double got;
int exp_i;
nsize = numberof (np);
if (tests_setjmp_sigfpe() == 0)
{
for (exp_i = 0; exp_i < numberof (exp_table); exp_i++)
{
exp = exp_table[exp_i];
for (sign = 0; sign >= -1; sign--)
{
got = mpn_get_d (np, nsize, sign, exp);
if (got != 0.0)
{
printf ("mpn_get_d wrong, didn't get 0.0 on underflow\n");
printf (" nsize %ld\n", (long) nsize);
printf (" exp %ld\n", exp);
printf (" sign %ld\n", (long) sign);
d_trace (" got ", got);
abort ();
}
}
}
}
else
{
printf ("Warning, underflow to zero tests skipped due to SIGFPE (exp=%ld)\n", exp);
}
tests_sigfpe_done ();
}
/* Expect large values to result in +/-inf, on IEEE systems. */
void
check_inf (void)
{
static const long exp_table[] = {
999999L, LONG_MAX,
};
static const mp_limb_t np[4] = { 1, 1, 1, 1 };
long exp;
mp_size_t nsize, sign, got_sign;
double got;
int exp_i;
if (! _GMP_IEEE_FLOATS)
return;
for (nsize = 1; nsize <= numberof (np); nsize++)
{
for (exp_i = 0; exp_i < numberof (exp_table); exp_i++)
{
exp = exp_table[exp_i];
for (sign = 0; sign >= -1; sign--)
{
got = mpn_get_d (np, nsize, sign, exp);
got_sign = (got >= 0 ? 0 : -1);
if (! tests_isinf (got))
{
printf ("mpn_get_d wrong, didn't get infinity\n");
bad:
printf (" nsize %ld\n", (long) nsize);
printf (" exp %ld\n", exp);
printf (" sign %ld\n", (long) sign);
d_trace (" got ", got);
printf (" got sign %ld\n", (long) got_sign);
abort ();
}
if (got_sign != sign)
{
printf ("mpn_get_d wrong sign on infinity\n");
goto bad;
}
}
}
}
}
/* Check values 2^n approaching and into IEEE denorm range.
Some systems might not support denorms, or might have traps setup, so
watch out for SIGFPE. */
void
check_ieee_denorm (void)
{
static long exp;
mp_limb_t n = 1;
long i;
mp_size_t sign;
double want, got;
if (! _GMP_IEEE_FLOATS)
return;
if (tests_setjmp_sigfpe() == 0)
{
exp = -1020;
want = 1.0;
for (i = 0; i > exp; i--)
want *= 0.5;
for ( ; exp > -1500 && want != 0.0; exp--)
{
for (sign = 0; sign >= -1; sign--)
{
got = mpn_get_d (&n, (mp_size_t) 1, sign, exp);
if (got != want)
{
printf ("mpn_get_d wrong on denorm\n");
printf (" n=1\n");
printf (" exp %ld\n", exp);
printf (" sign %ld\n", (long) sign);
d_trace (" got ", got);
d_trace (" want ", want);
abort ();
}
want = -want;
}
want *= 0.5;
FORCE_DOUBLE (want);
}
}
else
{
printf ("Warning, IEEE denorm tests skipped due to SIGFPE (exp=%ld)\n", exp);
}
tests_sigfpe_done ();
}
/* Check values 2^n approaching exponent overflow.
Some systems might trap on overflow, so watch out for SIGFPE. */
void
check_ieee_overflow (void)
{
static long exp;
mp_limb_t n = 1;
long i;
mp_size_t sign;
double want, got;
if (! _GMP_IEEE_FLOATS)
return;
if (tests_setjmp_sigfpe() == 0)
{
exp = 1010;
want = 1.0;
for (i = 0; i < exp; i++)
want *= 2.0;
for ( ; exp < 1050; exp++)
{
for (sign = 0; sign >= -1; sign--)
{
got = mpn_get_d (&n, (mp_size_t) 1, sign, exp);
if (got != want)
{
printf ("mpn_get_d wrong on overflow\n");
printf (" n=1\n");
printf (" exp %ld\n", exp);
printf (" sign %ld\n", (long) sign);
d_trace (" got ", got);
d_trace (" want ", want);
abort ();
}
want = -want;
}
want *= 2.0;
FORCE_DOUBLE (want);
}
}
else
{
printf ("Warning, IEEE overflow tests skipped due to SIGFPE (exp=%ld)\n", exp);
}
tests_sigfpe_done ();
}
/* ARM gcc 2.95.4 was seen generating bad code for ulong->double
conversions, resulting in for instance 0x81c25113 incorrectly converted.
This test exercises that value, to see mpn_get_d has avoided the
problem. */
void
check_0x81c25113 (void)
{
#if GMP_NUMB_BITS >= 32
double want = 2176995603.0;
double got;
mp_limb_t np[4];
mp_size_t nsize;
long exp;
if (tests_dbl_mant_bits() < 32)
return;
for (nsize = 1; nsize <= numberof (np); nsize++)
{
refmpn_zero (np, nsize-1);
np[nsize-1] = CNST_LIMB(0x81c25113);
exp = - (nsize-1) * GMP_NUMB_BITS;
got = mpn_get_d (np, nsize, (mp_size_t) 0, exp);
if (got != want)
{
printf ("mpn_get_d wrong on 2176995603 (0x81c25113)\n");
printf (" nsize %ld\n", (long) nsize);
printf (" exp %ld\n", exp);
d_trace (" got ", got);
d_trace (" want ", want);
abort ();
}
}
#endif
}
void
check_rand (void)
{
gmp_randstate_ptr rands = RANDS;
int rep, i;
unsigned long mant_bits;
long exp, exp_min, exp_max;
double got, want, d;
mp_size_t nalloc, nsize, sign;
mp_limb_t nhigh_mask;
mp_ptr np;
mant_bits = tests_dbl_mant_bits ();
if (mant_bits == 0)
return;
/* Allow for vax D format with exponent 127 to -128 only.
FIXME: Do something to probe for a valid exponent range. */
exp_min = -100 - mant_bits;
exp_max = 100 - mant_bits;
/* space for mant_bits */
nalloc = BITS_TO_LIMBS (mant_bits);
np = refmpn_malloc_limbs (nalloc);
nhigh_mask = MP_LIMB_T_MAX
>> (GMP_NAIL_BITS + nalloc * GMP_NUMB_BITS - mant_bits);
for (rep = 0; rep < 200; rep++)
{
/* random exp_min to exp_max, inclusive */
exp = exp_min + (long) gmp_urandomm_ui (rands, exp_max - exp_min + 1);
/* mant_bits worth of random at np */
if (rep & 1)
mpn_random (np, nalloc);
else
mpn_random2 (np, nalloc);
nsize = nalloc;
np[nsize-1] &= nhigh_mask;
MPN_NORMALIZE (np, nsize);
if (nsize == 0)
continue;
sign = (mp_size_t) gmp_urandomb_ui (rands, 1L) - 1;
/* want = {np,nsize}, converting one bit at a time */
want = 0.0;
for (i = 0, d = 1.0; i < mant_bits; i++, d *= 2.0)
if (np[i/GMP_NUMB_BITS] & (CNST_LIMB(1) << (i%GMP_NUMB_BITS)))
want += d;
if (sign < 0)
want = -want;
/* want = want * 2^exp */
for (i = 0; i < exp; i++)
want *= 2.0;
for (i = 0; i > exp; i--)
want *= 0.5;
got = mpn_get_d (np, nsize, sign, exp);
if (got != want)
{
printf ("mpn_get_d wrong on random data\n");
printf (" sign %ld\n", (long) sign);
mpn_trace (" n ", np, nsize);
printf (" nsize %ld\n", (long) nsize);
printf (" exp %ld\n", exp);
d_trace (" want ", want);
d_trace (" got ", got);
abort();
}
}
free (np);
}
int
main (void)
{
tests_start ();
mp_trace_base = -16;
check_onebit ();
check_twobit ();
check_inf ();
check_underflow ();
check_ieee_denorm ();
check_ieee_overflow ();
check_0x81c25113 ();
#if ! (defined (__vax) || defined (__vax__))
check_rand ();
#endif
tests_end ();
exit (0);
}