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/* Test file for mpfr_ui_sub.
Copyright 2000, 2001, 2002 Free Software Foundation.
This file is part of the MPFR Library.
The 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 2.1 of the License, or (at your
option) any later version.
The 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 MPFR Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <float.h>
#include <time.h>
#include "gmp.h"
#include "mpfr.h"
#include "mpfr-impl.h"
#include "mpfr-test.h"
void special _PROTO ((void));
void check _PROTO ((unsigned long, double, mp_rnd_t, double));
void check_two_sum _PROTO ((mp_prec_t));
void
special (void)
{
mpfr_t x, y, res;
int inexact;
mpfr_init (x);
mpfr_init (y);
mpfr_init (res);
mpfr_set_prec (x, 24);
mpfr_set_prec (y, 24);
mpfr_set_str_raw (y, "0.111100110001011010111");
inexact = mpfr_ui_sub (x, 1, y, GMP_RNDN);
if (inexact)
{
fprintf (stderr, "Wrong inexact flag: got %d, expected 0\n", inexact);
exit (1);
}
mpfr_set_prec (x, 24);
mpfr_set_prec (y, 24);
mpfr_set_str_raw (y, "0.111100110001011010111");
if ((inexact = mpfr_ui_sub (x, 38181761, y, GMP_RNDN)) >= 0)
{
fprintf (stderr, "Wrong inexact flag: got %d, expected -1\n", inexact);
exit (1);
}
mpfr_set_prec (x, 63);
mpfr_set_prec (y, 63);
mpfr_set_str_raw (y, "0.111110010010100100110101101010001001100101110001000101110111111E-1");
if ((inexact = mpfr_ui_sub (x, 1541116494, y, GMP_RNDN)) <= 0)
{
fprintf (stderr, "Wrong inexact flag: got %d, expected +1\n", inexact);
exit (1);
}
mpfr_set_prec (x, 32);
mpfr_set_prec (y, 32);
mpfr_set_str_raw (y, "0.11011000110111010001011100011100E-1");
if ((inexact = mpfr_ui_sub (x, 2000375416, y, GMP_RNDN)) >= 0)
{
fprintf (stderr, "Wrong inexact flag: got %d, expected -1\n", inexact);
exit (1);
}
mpfr_set_prec (x, 24);
mpfr_set_prec (y, 24);
mpfr_set_str_raw (y, "0.110011011001010011110111E-2");
if ((inexact = mpfr_ui_sub (x, 927694848, y, GMP_RNDN)) <= 0)
{
fprintf (stderr, "Wrong inexact flag: got %d, expected +1\n", inexact);
exit (1);
}
/* bug found by Mathieu Dutour, 12 Apr 2001 */
mpfr_set_prec (x, 5);
mpfr_set_prec (y, 5);
mpfr_set_prec (res, 5);
mpfr_set_str_raw (x, "1e-12");
mpfr_ui_sub (y, 1, x, GMP_RNDD);
mpfr_set_str_raw (res, "0.11111");
if (mpfr_cmp (y, res))
{
fprintf (stderr, "Error in mpfr_ui_sub (y, 1, x, GMP_RNDD) for x=2^(-12)\nexpected 1.1111e-1, got ");
mpfr_out_str (stderr, 2, 0, y, GMP_RNDN);
fprintf (stderr, "\n");
exit (1);
}
mpfr_ui_sub (y, 1, x, GMP_RNDU);
mpfr_set_str_raw (res, "1.0");
if (mpfr_cmp (y, res))
{
fprintf (stderr, "Error in mpfr_ui_sub (y, 1, x, GMP_RNDU) for x=2^(-12)\nexpected 1.0, got ");
mpfr_out_str (stderr, 2, 0, y, GMP_RNDN);
fprintf (stderr, "\n");
exit (1);
}
mpfr_ui_sub (y, 1, x, GMP_RNDN);
mpfr_set_str_raw (res, "1.0");
if (mpfr_cmp (y, res))
{
fprintf (stderr, "Error in mpfr_ui_sub (y, 1, x, GMP_RNDN) for x=2^(-12)\nexpected 1.0, got ");
mpfr_out_str (stderr, 2, 0, y, GMP_RNDN);
fprintf (stderr, "\n");
exit (1);
}
mpfr_clear (x);
mpfr_clear (y);
mpfr_clear (res);
}
/* checks that y/x gives the same results in double
and with mpfr with 53 bits of precision */
void
check (unsigned long y, double x, mp_rnd_t rnd_mode, double z1)
{
double z2; mpfr_t xx, zz;
mpfr_init2(xx, 53);
mpfr_init2(zz, 53);
mpfr_set_d(xx, x, rnd_mode);
mpfr_ui_sub(zz, y, xx, rnd_mode);
z2 = mpfr_get_d1 (zz);
if (z1!=z2 && !(isnan(z1) && isnan(z2))) {
printf("expected difference is %1.20e, got %1.20e\n",z1,z2);
printf("mpfr_ui_sub failed for y=%lu x=%1.20e with rnd_mode=%s\n",
y, x, mpfr_print_rnd_mode(rnd_mode));
exit(1);
}
mpfr_clear(xx); mpfr_clear(zz);
}
/* if u = o(x-y), v = o(u-x), w = o(v+y), then x-y = u-w */
void
check_two_sum (mp_prec_t p)
{
unsigned int x;
mpfr_t y, u, v, w;
mp_rnd_t rnd;
int inexact;
mpfr_init2 (y, p);
mpfr_init2 (u, p);
mpfr_init2 (v, p);
mpfr_init2 (w, p);
do
{
x = LONG_RAND ();
}
while (x < 1);
mpfr_random (y);
rnd = LONG_RAND() % 4;
rnd = GMP_RNDN;
inexact = mpfr_ui_sub (u, x, y, GMP_RNDN);
mpfr_sub_ui (v, u, x, GMP_RNDN);
mpfr_add (w, v, y, GMP_RNDN);
/* as u = (x-y) + w, we should have inexact and w of same sign */
if (((inexact == 0) && mpfr_cmp_ui (w, 0)) ||
((inexact > 0) && (mpfr_cmp_ui (w, 0) <= 0)) ||
((inexact < 0) && (mpfr_cmp_ui (w, 0) >= 0)))
{
fprintf (stderr, "Wrong inexact flag for prec=%u, rnd=%s\n", (unsigned)p,
mpfr_print_rnd_mode (rnd));
printf ("x=%u\n", x);
printf ("y="); mpfr_print_binary(y); putchar('\n');
printf ("u="); mpfr_print_binary(u); putchar('\n');
printf ("v="); mpfr_print_binary(v); putchar('\n');
printf ("w="); mpfr_print_binary(w); putchar('\n');
printf ("inexact = %d\n", inexact);
exit (1);
}
mpfr_clear (y);
mpfr_clear (u);
mpfr_clear (v);
mpfr_clear (w);
}
int
main (int argc, char *argv[])
{
mp_prec_t p;
unsigned k;
tests_start_mpfr ();
special ();
for (p=2; p<100; p++)
for (k=0; k<100; k++)
check_two_sum (p);
#ifdef HAVE_INFS
check (1, DBL_POS_INF, GMP_RNDN, DBL_NEG_INF);
check (1, DBL_NEG_INF, GMP_RNDN, DBL_POS_INF);
check (1, DBL_NAN, GMP_RNDN, DBL_NAN);
#endif
check(1196426492, 1.4218093058435347e-3, GMP_RNDN, 1.1964264919985781e9);
check(1092583421, -1.0880649218158844e9, GMP_RNDN, 2.1806483428158845901e9);
check(948002822, 1.22191250737771397120e+20, GMP_RNDN,
-1.2219125073682338611e20);
check(832100416, 4.68311314939691330000e-215, GMP_RNDD,
8.3210041599999988079e8);
check(1976245324, 1.25296395864546893357e+232, GMP_RNDZ,
-1.2529639586454686577e232);
check(2128997392, -1.08496826129284207724e+187, GMP_RNDU,
1.0849682612928422704e187);
check(293607738, -1.9967571564050541e-5, GMP_RNDU, 2.9360773800002003e8);
check(354270183, 2.9469161763489528e3, GMP_RNDN, 3.5426723608382362e8);
tests_end_mpfr ();
return 0;
}
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