/* Test file for mpfr_subnormalize.
Copyright 2005-2017 Free Software Foundation, Inc.
Contributed by the AriC and Caramba projects, INRIA.
This file is part of the GNU MPFR Library.
The GNU MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser 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 MPFR Library 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 Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include "mpfr-test.h"
static const struct {
const char *in;
int i;
mpfr_rnd_t rnd;
const char *out;
int j;
} tab[] = { /* 4th field: use the mpfr_dump format, in case of error. */
{"1E1", 0, MPFR_RNDN, "0.100000000E2", 0},
{"1E1", -1, MPFR_RNDZ, "0.100000000E2", -1},
{"1E1", -1, MPFR_RNDD, "0.100000000E2", -1},
{"1E1", 1, MPFR_RNDU, "0.100000000E2", 1},
{"0.10000E-10", 0, MPFR_RNDN, "0.100000000E-10", 0},
{"0.10001E-10", 0, MPFR_RNDN, "0.100000000E-10", -1},
{"0.11001E-10", 0, MPFR_RNDN, "0.100000000E-9", 1},
{"0.11001E-10", 0, MPFR_RNDZ, "0.100000000E-10", -1},
{"0.11001E-10", 0, MPFR_RNDU, "0.100000000E-9", 1},
{"0.11000E-10", 0, MPFR_RNDN, "0.100000000E-9", 1},
{"0.11000E-10", -1, MPFR_RNDN, "0.100000000E-9", 1},
{"0.11000E-10", 1, MPFR_RNDN, "0.100000000E-10", -1},
{"0.11111E-8", 0, MPFR_RNDN, "0.100000000E-7", 1},
{"0.10111E-8", 0, MPFR_RNDN, "0.110000000E-8", 1},
{"0.11110E-8", -1, MPFR_RNDN, "0.100000000E-7", 1},
{"0.10110E-8", 1, MPFR_RNDN, "0.101000000E-8", -1}
};
static void
check1 (void)
{
mpfr_t x;
int i, j, k, s, old_inex, tiny, expj;
mpfr_exp_t emin, emax;
unsigned int expflags, flags;
emin = mpfr_get_emin ();
emax = mpfr_get_emax ();
mpfr_set_default_prec (9);
mpfr_set_emin (-10);
mpfr_set_emax (10);
mpfr_init (x);
for (i = 0; i < (sizeof (tab) / sizeof (tab[0])); i++)
for (s = 0; s <= (tab[i].rnd == MPFR_RNDN); s++)
for (k = 0; k <= 1; k++)
{
mpfr_set_str (x, tab[i].in, 2, MPFR_RNDN);
old_inex = tab[i].i;
expj = tab[i].j;
if (s)
{
mpfr_neg (x, x, MPFR_RNDN);
old_inex = - old_inex;
expj = - expj;
}
if (k && old_inex)
old_inex = old_inex < 0 ? INT_MIN : INT_MAX;
tiny = MPFR_GET_EXP (x) <= -3;
mpfr_clear_flags ();
j = mpfr_subnormalize (x, old_inex, tab[i].rnd);
expflags =
(tiny ? MPFR_FLAGS_UNDERFLOW : 0) |
(expj ? MPFR_FLAGS_INEXACT : 0);
flags = __gmpfr_flags;
if (s)
mpfr_neg (x, x, MPFR_RNDN);
if (mpfr_cmp_str (x, tab[i].out, 2, MPFR_RNDN) != 0 ||
flags != expflags || ! SAME_SIGN (j, expj))
{
const char *sgn = s ? "-" : "";
printf ("Error for i = %d (old_inex = %d), k = %d, x = %s%s\n"
"Expected: %s%s\nGot: ", i, old_inex, k,
sgn, tab[i].in, sgn, tab[i].out);
if (s)
mpfr_neg (x, x, MPFR_RNDN);
mpfr_dump (x);
printf ("Expected flags = %u, got %u\n", expflags, flags);
printf ("Expected ternary value = %d, got %d\n", expj, j);
exit (1);
}
}
mpfr_clear (x);
MPFR_ASSERTN (mpfr_get_emin () == -10);
MPFR_ASSERTN (mpfr_get_emax () == 10);
set_emin (emin);
set_emax (emax);
}
/* bug found by Kevin P. Rauch on 22 Oct 2007 */
static void
check2 (void)
{
mpfr_t x, y, z;
int tern;
mpfr_exp_t emin;
emin = mpfr_get_emin ();
mpfr_init2 (x, 32);
mpfr_init2 (y, 32);
mpfr_init2 (z, 32);
mpfr_set_ui (x, 0xC0000000U, MPFR_RNDN);
mpfr_neg (x, x, MPFR_RNDN);
mpfr_set_ui (y, 0xFFFFFFFEU, MPFR_RNDN);
mpfr_set_exp (x, 0);
mpfr_set_exp (y, 0);
mpfr_set_emin (-29);
tern = mpfr_mul (z, x, y, MPFR_RNDN);
/* z = -0.BFFFFFFE, tern > 0 */
tern = mpfr_subnormalize (z, tern, MPFR_RNDN);
/* z should be -0.75 */
MPFR_ASSERTN (tern < 0 && mpfr_cmp_si_2exp (z, -3, -2) == 0);
mpfr_clear (x);
mpfr_clear (y);
mpfr_clear (z);
MPFR_ASSERTN (mpfr_get_emin () == -29);
set_emin (emin);
}
/* bug found by Kevin P. Rauch on 22 Oct 2007 */
static void
check3 (void)
{
mpfr_t x, y, z;
int tern;
mpfr_exp_t emin;
emin = mpfr_get_emin ();
mpfr_init2 (x, 32);
mpfr_init2 (y, 32);
mpfr_init2 (z, 32);
mpfr_set_ui (x, 0xBFFFFFFFU, MPFR_RNDN); /* 3221225471/2^32 */
mpfr_set_ui (y, 0x80000001U, MPFR_RNDN); /* 2147483649/2^32 */
mpfr_set_exp (x, 0);
mpfr_set_exp (y, 0);
mpfr_set_emin (-1);
/* the exact product is 6917529028714823679/2^64, which is rounded to
3/8 = 0.375, which is smaller, thus tern < 0 */
tern = mpfr_mul (z, x, y, MPFR_RNDN);
MPFR_ASSERTN (tern < 0 && mpfr_cmp_ui_2exp (z, 3, -3) == 0);
tern = mpfr_subnormalize (z, tern, MPFR_RNDN);
/* since emin = -1, and EXP(z)=-1, z should be rounded to precision
EXP(z)-emin+1 = 1, i.e., z should be a multiple of the smallest possible
positive representable value with emin=-1, which is 1/4. The two
possible values are 1/4 and 2/4, which are at equal distance of z.
But since tern < 0, we should choose the largest value, i.e., 2/4. */
MPFR_ASSERTN (tern > 0 && mpfr_cmp_ui_2exp (z, 1, -1) == 0);
/* here is another test for the alternate case, where z was rounded up
first, thus we have to round down */
mpfr_set_str_binary (x, "0.11111111111010110101011011011011");
mpfr_set_str_binary (y, "0.01100000000001111100000000001110");
tern = mpfr_mul (z, x, y, MPFR_RNDN);
MPFR_ASSERTN (tern > 0 && mpfr_cmp_ui_2exp (z, 3, -3) == 0);
tern = mpfr_subnormalize (z, tern, MPFR_RNDN);
MPFR_ASSERTN (tern < 0 && mpfr_cmp_ui_2exp (z, 1, -2) == 0);
/* finally the case where z was exact, which we simulate here */
mpfr_set_ui_2exp (z, 3, -3, MPFR_RNDN);
tern = mpfr_subnormalize (z, 0, MPFR_RNDN);
MPFR_ASSERTN (tern > 0 && mpfr_cmp_ui_2exp (z, 1, -1) == 0);
mpfr_clear (x);
mpfr_clear (y);
mpfr_clear (z);
MPFR_ASSERTN (mpfr_get_emin () == -1);
set_emin (emin);
}
int
main (int argc, char *argv[])
{
tests_start_mpfr ();
check1 ();
check2 ();
check3 ();
tests_end_mpfr ();
return 0;
}