tsub_d.c revision 1.1.1.5 
1/* Test file for mpfr_sub_d
2
3Copyright 2007-2020 Free Software Foundation, Inc.
4Contributed by the AriC and Caramba projects, INRIA.
5
6This file is part of the GNU MPFR Library.
7
8The GNU MPFR Library is free software; you can redistribute it and/or modify
9it under the terms of the GNU Lesser General Public License as published by
10the Free Software Foundation; either version 3 of the License, or (at your
11option) any later version.
12
13The GNU MPFR Library is distributed in the hope that it will be useful, but
14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
16License for more details.
17
18You should have received a copy of the GNU Lesser General Public License
19along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
20https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
2151 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
22
23#include <float.h>
24
25#include "mpfr-test.h"
26
27static void
28check_nans (void)
29{
30  mpfr_t  x, y;
31  int inexact;
32
33  mpfr_init2 (x, 123);
34  mpfr_init2 (y, 123);
35
36  /* nan - 1.0 is nan */
37  mpfr_set_nan (x);
38  mpfr_clear_flags ();
39  inexact = mpfr_sub_d (y, x, 1.0, MPFR_RNDN);
40  MPFR_ASSERTN (inexact == 0);
41  MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_NAN);
42  MPFR_ASSERTN (mpfr_nan_p (y));
43
44  /* +inf - 1.0 == +inf */
45  mpfr_set_inf (x, 1);
46  mpfr_clear_flags ();
47  inexact = mpfr_sub_d (y, x, 1.0, MPFR_RNDN);
48  MPFR_ASSERTN (inexact == 0);
49  MPFR_ASSERTN (__gmpfr_flags == 0);
50  MPFR_ASSERTN (mpfr_inf_p (y));
51  MPFR_ASSERTN (MPFR_IS_POS (y));
52
53  /* -inf - 1.0 == -inf */
54  mpfr_set_inf (x, -1);
55  mpfr_clear_flags ();
56  inexact = mpfr_sub_d (y, x, 1.0, MPFR_RNDN);
57  MPFR_ASSERTN (inexact == 0);
58  MPFR_ASSERTN (__gmpfr_flags == 0);
59  MPFR_ASSERTN (mpfr_inf_p (y));
60  MPFR_ASSERTN (MPFR_IS_NEG (y));
61
62  mpfr_clear (x);
63  mpfr_clear (y);
64}
65
66#define TEST_FUNCTION mpfr_sub_d
67#define DOUBLE_ARG2
68#define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS)
69#include "tgeneric.c"
70
71int
72main (void)
73{
74  mpfr_t x, y, z;
75  double d;
76  int inexact;
77
78  tests_start_mpfr ();
79
80  /* check with enough precision */
81  mpfr_init2 (x, IEEE_DBL_MANT_DIG);
82  mpfr_init2 (y, IEEE_DBL_MANT_DIG);
83  mpfr_init2 (z, IEEE_DBL_MANT_DIG);
84
85  mpfr_set_str (y, "4096", 10, MPFR_RNDN);
86  d = 0.125;
87  mpfr_clear_flags ();
88  inexact = mpfr_sub_d (x, y, d, MPFR_RNDN);
89  if (inexact != 0)
90    {
91      printf ("Inexact flag error in mpfr_sub_d\n");
92      exit (1);
93    }
94  mpfr_set_str (z, "4095.875", 10, MPFR_RNDN);
95  if (mpfr_cmp (z, x))
96    {
97      printf ("Error in mpfr_sub_d (");
98      mpfr_out_str (stdout, 10, 7, y, MPFR_RNDN);
99      printf (" + %.20g)\nexpected ", d);
100      mpfr_out_str (stdout, 10, 0, z, MPFR_RNDN);
101      printf ("\ngot     ");
102      mpfr_out_str (stdout, 10, 0, x, MPFR_RNDN);
103      printf ("\n");
104      exit (1);
105    }
106  mpfr_clears (x, y, z, (mpfr_ptr) 0);
107
108  check_nans ();
109
110  test_generic (MPFR_PREC_MIN, 1000, 100);
111
112  tests_end_mpfr ();
113  return 0;
114}
115