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/* Test mpz_get_d_2exp.
Copyright 2002, 2003, 2012 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 <stdio.h>
#include <stdlib.h>
#include "gmp-impl.h"
#include "tests.h"
static void
check_zero (void)
{
mpz_t z;
double got, want;
long got_exp, want_exp;
mpz_init_set_ui (z, 0);
want = 0.0;
want_exp = 0;
got = mpz_get_d_2exp (&got_exp, z);
if (got != want || got_exp != want_exp)
{
printf ("mpz_get_d_2exp wrong on zero\n");
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);
}
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);
}
/* 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_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);
}
int
main (void)
{
tests_start ();
mp_trace_base = -16;
check_zero ();
check_onebit ();
check_round ();
check_rand ();
tests_end ();
exit (0);
}
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