xref: /netbsd-src/external/lgpl3/mpfr/dist/tests/tsub_d.c (revision a4ddc2c8fb9af816efe3b1c375a5530aef0e89e9)
1 /* Test file for mpfr_sub_d
2 
3 Copyright 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4 Contributed by the Arenaire and Cacao projects, INRIA.
5 
6 This file is part of the GNU MPFR Library.
7 
8 The GNU MPFR Library is free software; you can redistribute it and/or modify
9 it under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or (at your
11 option) any later version.
12 
13 The GNU MPFR Library is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
16 License for more details.
17 
18 You should have received a copy of the GNU Lesser General Public License
19 along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
20 http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
21 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
22 
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <float.h>
26 
27 #include "mpfr-test.h"
28 
29 #if MPFR_VERSION >= MPFR_VERSION_NUM(2,4,0)
30 
31 static void
32 check_nans (void)
33 {
34   mpfr_t  x, y;
35   int inexact;
36 
37   mpfr_init2 (x, 123);
38   mpfr_init2 (y, 123);
39 
40   /* nan - 1.0 is nan */
41   mpfr_set_nan (x);
42   mpfr_clear_flags ();
43   inexact = mpfr_sub_d (y, x, 1.0, MPFR_RNDN);
44   MPFR_ASSERTN (inexact == 0);
45   MPFR_ASSERTN ((__gmpfr_flags ^ MPFR_FLAGS_NAN) == 0);
46   MPFR_ASSERTN (mpfr_nan_p (y));
47 
48   /* +inf - 1.0 == +inf */
49   mpfr_set_inf (x, 1);
50   mpfr_clear_flags ();
51   inexact = mpfr_sub_d (y, x, 1.0, MPFR_RNDN);
52   MPFR_ASSERTN (inexact == 0);
53   MPFR_ASSERTN (__gmpfr_flags == 0);
54   MPFR_ASSERTN (mpfr_inf_p (y));
55   MPFR_ASSERTN (MPFR_IS_POS (y));
56 
57   /* -inf - 1.0 == -inf */
58   mpfr_set_inf (x, -1);
59   mpfr_clear_flags ();
60   inexact = mpfr_sub_d (y, x, 1.0, MPFR_RNDN);
61   MPFR_ASSERTN (inexact == 0);
62   MPFR_ASSERTN (__gmpfr_flags == 0);
63   MPFR_ASSERTN (mpfr_inf_p (y));
64   MPFR_ASSERTN (MPFR_IS_NEG (y));
65 
66   mpfr_clear (x);
67   mpfr_clear (y);
68 }
69 
70 #define TEST_FUNCTION mpfr_sub_d
71 #define DOUBLE_ARG2
72 #define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS)
73 #include "tgeneric.c"
74 
75 int
76 main (void)
77 {
78   mpfr_t x, y, z;
79   double d;
80   int inexact;
81   tests_start_mpfr ();
82 
83   /* check with enough precision */
84   mpfr_init2 (x, IEEE_DBL_MANT_DIG);
85   mpfr_init2 (y, IEEE_DBL_MANT_DIG);
86   mpfr_init2 (z, IEEE_DBL_MANT_DIG);
87 
88   mpfr_set_str (y, "4096", 10, MPFR_RNDN);
89   d = 0.125;
90   mpfr_clear_flags ();
91   inexact = mpfr_sub_d (x, y, d, MPFR_RNDN);
92   if (inexact != 0)
93     {
94       printf ("Inexact flag error in mpfr_sub_d\n");
95       exit (1);
96     }
97   mpfr_set_str (z, "4095.875", 10, MPFR_RNDN);
98   if (mpfr_cmp (z, x))
99     {
100       printf ("Error in mpfr_sub_d (");
101       mpfr_out_str (stdout, 10, 7, y, MPFR_RNDN);
102       printf (" + %.20g)\nexpected ", d);
103       mpfr_out_str (stdout, 10, 0, z, MPFR_RNDN);
104       printf ("\ngot     ");
105       mpfr_out_str (stdout, 10, 0, x, MPFR_RNDN);
106       printf ("\n");
107       exit (1);
108     }
109   mpfr_clears (x, y, z, (mpfr_ptr) 0);
110 
111   check_nans ();
112 
113   test_generic (2, 1000, 100);
114 
115   tests_end_mpfr ();
116   return 0;
117 }
118 
119 #else
120 
121 int
122 main (void)
123 {
124   printf ("Warning! Test disabled for this MPFR version.\n");
125   return 0;
126 }
127 
128 #endif
129