buildtools/gcc/mpfr/tests/tget_ld_2exp.c
Fredrik Holmqvist 974e12c1f0 Upgrade mpfr to 4.0.1
Old version was 3.1.2 and is quite old: 2013-03-13
A lot has happened since then 4.0.1 is from 2018-02-07
2018-07-04 20:21:01 +02:00

143 lines
3.6 KiB
C

/* Test mpfr_get_ld_2exp.
Copyright 2006-2018 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 <float.h>
#include "mpfr-test.h"
/* Check that hardware rounding doesn't make mpfr_get_ld_2exp return a value
outside its defined range. */
static void
check_round (void)
{
static const unsigned long data[] = {1, 32, 53, 54, 63, 64, 65, 127, 128, 256, 512 };
mpfr_t f;
long double got;
long got_exp;
int i, rnd_mode, neg;
mpfr_init2 (f, 1024L);
for (rnd_mode = 0; rnd_mode < MPFR_RND_MAX ; rnd_mode++)
{
for (i = 0; i < (int) numberof (data); i++)
{
mpfr_set_ui (f, 1L, MPFR_RNDZ);
mpfr_mul_2exp (f, f, data[i], MPFR_RNDZ);
mpfr_sub_ui (f, f, 1L, MPFR_RNDZ);
for (neg = 0; neg <= 1; neg++)
{
got = mpfr_get_ld_2exp (&got_exp, f, (mpfr_rnd_t) rnd_mode);
if (neg == 0
? (got < 0.5 || got >= 1.0)
: (got <= -1.0 || got > -0.5))
{
printf ("mpfr_get_ld_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]);
printf (" f ");
mpfr_out_str (stdout, 2, 0, f, MPFR_RNDN);
printf ("\n");
d_trace (" got ", got);
printf (" got exp %ld\n", got_exp);
exit(1);
}
mpfr_neg (f, f, MPFR_RNDZ);
}
}
}
mpfr_clear (f);
}
static void
check_inf_nan (void)
{
#if !defined(MPFR_ERRDIVZERO)
mpfr_t x;
double d;
long exp;
mpfr_init2 (x, 123);
mpfr_set_inf (x, 1);
d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ);
MPFR_ASSERTN (d > 0);
MPFR_ASSERTN (DOUBLE_ISINF (d));
mpfr_set_inf (x, -1);
d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ);
MPFR_ASSERTN (d < 0);
MPFR_ASSERTN (DOUBLE_ISINF (d));
mpfr_set_nan (x);
d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ);
MPFR_ASSERTN (DOUBLE_ISNAN (d));
mpfr_clear (x);
#endif
}
static void
bug20090520 (void)
{
mpfr_t x;
long double d, e;
int i;
mpfr_init (x);
mpfr_set_ui (x, 1, MPFR_RNDN);
d = 1.0;
mpfr_div_2exp (x, x, 16383, MPFR_RNDN);
for (i = 0; i < 16383; i++)
d *= 0.5;
e = mpfr_get_ld (x, MPFR_RNDN);
if (e != d)
{
printf ("mpfr_get_ld(1e-16383) failed\n");
printf ("expected %.20Le\n", d);
printf ("got %.20Le\n", e);
exit (1);
}
mpfr_clear (x);
}
int
main (void)
{
tests_start_mpfr ();
mpfr_test_init ();
bug20090520 ();
check_round ();
check_inf_nan ();
tests_end_mpfr ();
return 0;
}