/* Test file for mpfr_div_ui.
Copyright 1999-2017 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 <float.h>
#include "mpfr-test.h"
static void
check (const char *ds, unsigned long u, mpfr_rnd_t rnd, const char *es)
{
mpfr_t x, y;
mpfr_init2 (x, 53);
mpfr_init2 (y, 53);
mpfr_set_str1 (x, ds);
mpfr_div_ui (y, x, u, rnd);
if (mpfr_cmp_str1 (y, es))
{
printf ("mpfr_div_ui failed for x=%s, u=%lu, rnd=%s\n", ds, u,
mpfr_print_rnd_mode (rnd));
printf ("expected result is %s, got", es);
mpfr_out_str(stdout, 10, 0, y, MPFR_RNDN);
exit (1);
}
mpfr_clear (x);
mpfr_clear (y);
}
static void
special (void)
{
mpfr_t x, y;
unsigned xprec, yprec;
mpfr_init (x);
mpfr_init (y);
mpfr_set_prec (x, 32);
mpfr_set_prec (y, 32);
mpfr_set_ui (x, 1, MPFR_RNDN);
mpfr_div_ui (y, x, 3, MPFR_RNDN);
mpfr_set_prec (x, 100);
mpfr_set_prec (y, 100);
mpfr_urandomb (x, RANDS);
mpfr_div_ui (y, x, 123456, MPFR_RNDN);
mpfr_set_ui (x, 0, MPFR_RNDN);
mpfr_div_ui (y, x, 123456789, MPFR_RNDN);
if (mpfr_cmp_ui (y, 0))
{
printf ("mpfr_div_ui gives non-zero for 0/ui\n");
exit (1);
}
/* bug found by Norbert Mueller, 21 Aug 2001 */
mpfr_set_prec (x, 110);
mpfr_set_prec (y, 60);
mpfr_set_str_binary (x, "0.110101110011111110011111001110011001110111000000111110001000111011000011E-44");
mpfr_div_ui (y, x, 17, MPFR_RNDN);
mpfr_set_str_binary (x, "0.11001010100101100011101110000001100001010110101001010011011E-48");
if (mpfr_cmp (x, y))
{
printf ("Error in x/17 for x=1/16!\n");
printf ("Expected ");
mpfr_out_str (stdout, 2, 0, x, MPFR_RNDN);
printf ("\nGot ");
mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN);
printf ("\n");
exit (1);
}
/* corner case */
mpfr_set_prec (x, 2 * mp_bits_per_limb);
mpfr_set_prec (y, 2);
mpfr_set_ui (x, 4, MPFR_RNDN);
mpfr_nextabove (x);
mpfr_div_ui (y, x, 2, MPFR_RNDN); /* exactly in the middle */
MPFR_ASSERTN(mpfr_cmp_ui (y, 2) == 0);
mpfr_set_prec (x, 3 * mp_bits_per_limb);
mpfr_set_prec (y, 2);
mpfr_set_ui (x, 2, MPFR_RNDN);
mpfr_nextabove (x);
mpfr_div_ui (y, x, 2, MPFR_RNDN);
MPFR_ASSERTN(mpfr_cmp_ui (y, 1) == 0);
mpfr_set_prec (x, 3 * mp_bits_per_limb);
mpfr_set_prec (y, 2);
mpfr_set_si (x, -4, MPFR_RNDN);
mpfr_nextbelow (x);
mpfr_div_ui (y, x, 2, MPFR_RNDD);
MPFR_ASSERTN(mpfr_cmp_si (y, -3) == 0);
for (xprec = 53; xprec <= 128; xprec++)
{
mpfr_set_prec (x, xprec);
mpfr_set_str_binary (x, "0.1100100100001111110011111000000011011100001100110111E2");
for (yprec = 53; yprec <= 128; yprec++)
{
mpfr_set_prec (y, yprec);
mpfr_div_ui (y, x, 1, MPFR_RNDN);
if (mpfr_cmp(x,y))
{
printf ("division by 1.0 fails for xprec=%u, yprec=%u\n", xprec, yprec);
printf ("expected "); mpfr_print_binary (x); puts ("");
printf ("got "); mpfr_print_binary (y); puts ("");
exit (1);
}
}
}
/* Bug reported by Mark Dickinson, 6 Nov 2007 */
mpfr_set_si (x, 0, MPFR_RNDN);
mpfr_set_si (y, -1, MPFR_RNDN);
mpfr_div_ui (y, x, 4, MPFR_RNDN);
MPFR_ASSERTN(MPFR_IS_ZERO(y) && MPFR_IS_POS(y));
mpfr_clear (x);
mpfr_clear (y);
}
static void
check_inexact (void)
{
mpfr_t x, y, z;
mpfr_prec_t px, py;
int inexact, cmp;
unsigned long int u;
int rnd;
mpfr_init (x);
mpfr_init (y);
mpfr_init (z);
for (px=2; px<300; px++)
{
mpfr_set_prec (x, px);
mpfr_urandomb (x, RANDS);
do
{
u = randlimb ();
}
while (u == 0);
for (py=2; py<300; py++)
{
mpfr_set_prec (y, py);
mpfr_set_prec (z, py + mp_bits_per_limb);
for (rnd = 0; rnd < MPFR_RND_MAX; rnd++)
{
inexact = mpfr_div_ui (y, x, u, (mpfr_rnd_t) rnd);
if (mpfr_mul_ui (z, y, u, (mpfr_rnd_t) rnd))
{
printf ("z <- y * u should be exact for u=%lu\n", u);
printf ("y="); mpfr_print_binary (y); puts ("");
printf ("z="); mpfr_print_binary (z); puts ("");
exit (1);
}
cmp = mpfr_cmp (z, x);
if (((inexact == 0) && (cmp != 0)) ||
((inexact > 0) && (cmp <= 0)) ||
((inexact < 0) && (cmp >= 0)))
{
printf ("Wrong inexact flag for u=%lu, rnd=%s\n", u,
mpfr_print_rnd_mode ((mpfr_rnd_t) rnd));
printf ("x="); mpfr_print_binary (x); puts ("");
printf ("y="); mpfr_print_binary (y); puts ("");
exit (1);
}
}
}
}
mpfr_clear (x);
mpfr_clear (y);
mpfr_clear (z);
}
#define TEST_FUNCTION mpfr_div_ui
#define ULONG_ARG2
#define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS)
#include "tgeneric.c"
int
main (int argc, char **argv)
{
mpfr_t x;
tests_start_mpfr ();
special ();
check_inexact ();
check("1.0", 3, MPFR_RNDN, "3.3333333333333331483e-1");
check("1.0", 3, MPFR_RNDZ, "3.3333333333333331483e-1");
check("1.0", 3, MPFR_RNDU, "3.3333333333333337034e-1");
check("1.0", 3, MPFR_RNDD, "3.3333333333333331483e-1");
check("1.0", 2116118, MPFR_RNDN, "4.7256343927890600483e-7");
check("1.098612288668109782", 5, MPFR_RNDN, "0.21972245773362195087");
mpfr_init2 (x, 53);
mpfr_set_ui (x, 3, MPFR_RNDD);
mpfr_log (x, x, MPFR_RNDD);
mpfr_div_ui (x, x, 5, MPFR_RNDD);
if (mpfr_cmp_str1 (x, "0.21972245773362189536"))
{
printf ("Error in mpfr_div_ui for x=ln(3), u=5\n");
exit (1);
}
mpfr_clear (x);
test_generic (2, 200, 100);
tests_end_mpfr ();
return 0;
}