xref: /netbsd-src/external/lgpl3/mpfr/dist/tests/tpow3.c (revision b49cc1491953ef2348eff9c84520ffd0678a5c8d)
1 /* Test file for mpfr_pow.
2 
3 Copyright 2001, 2002, 2003, 2004, 2005, 2006, 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 <limits.h>
25 #include <stdlib.h>
26 
27 #include "mpfr-test.h"
28 
29 
30 int
31 main (int argc, char *argv[])
32 {
33   mpfr_t x, y, z;
34 
35   mpfr_prec_t prec, yprec;
36   mpfr_t t, s;
37   mpfr_rnd_t rnd;
38   int inexact, compare, compare2;
39   unsigned int n, err;
40 
41   mpfr_prec_t p0=2, p1=100;
42   unsigned int N=25;
43 
44   tests_start_mpfr ();
45 
46   mpfr_init (x);
47   mpfr_init2 (y,sizeof(unsigned long int)*CHAR_BIT);
48   mpfr_init (z);
49 
50   mpfr_init (s);
51   mpfr_init (t);
52 
53   /* generic test */
54   for (prec = p0; prec <= p1; prec++)
55     {
56       mpfr_set_prec (x, prec);
57       mpfr_set_prec (s, sizeof(unsigned long int)*CHAR_BIT);
58       mpfr_set_prec (z, prec);
59       mpfr_set_prec (t, prec);
60       yprec = prec + 10;
61 
62       for (n=0; n<N; n++)
63         {
64           mpfr_urandomb (x, RANDS);
65           mpfr_urandomb (s, RANDS);
66           if (randlimb () % 2)
67             mpfr_neg (s, s, MPFR_RNDN);
68           rnd = RND_RAND ();
69           mpfr_set_prec (y, yprec);
70           compare = mpfr_pow (y, x, s, rnd);
71           err = (rnd == MPFR_RNDN) ? yprec + 1 : yprec;
72           if (mpfr_can_round (y, err, rnd, rnd, prec))
73             {
74               mpfr_set (t, y, rnd);
75               inexact = mpfr_pow (z, x, s, rnd);
76               if (mpfr_cmp (t, z))
77                 {
78                   printf ("results differ for x^y with x=");
79                   mpfr_out_str (stdout, 2, prec, x, MPFR_RNDN);
80                   printf (" y=");
81                   mpfr_out_str (stdout, 2, 0, s, MPFR_RNDN);
82                   printf (" prec=%u rnd_mode=%s\n", (unsigned int) prec,
83                           mpfr_print_rnd_mode (rnd));
84                   printf ("got      ");
85                   mpfr_out_str (stdout, 2, prec, z, MPFR_RNDN);
86                   puts ("");
87                   printf ("expected ");
88                   mpfr_out_str (stdout, 2, prec, t, MPFR_RNDN);
89                   puts ("");
90                   printf ("approx  ");
91                   mpfr_print_binary (y);
92                   puts ("");
93                   exit (1);
94                 }
95               compare2 = mpfr_cmp (t, y);
96               /* if rounding to nearest, cannot know the sign of t - f(x)
97                  because of composed rounding: y = o(f(x)) and t = o(y) */
98               if ((rnd != MPFR_RNDN) && (compare * compare2 >= 0))
99                 compare = compare + compare2;
100               else
101                 compare = inexact; /* cannot determine sign(t-f(x)) */
102               if (((inexact == 0) && (compare != 0)) ||
103                   ((inexact > 0) && (compare <= 0)) ||
104                   ((inexact < 0) && (compare >= 0)))
105                 {
106                   printf ("Wrong inexact flag for rnd=%s: expected %d, got %d"
107                           "\n", mpfr_print_rnd_mode (rnd), compare, inexact);
108                   printf ("x="); mpfr_print_binary (x); puts ("");
109                   printf ("y="); mpfr_print_binary (y); puts ("");
110                   printf ("t="); mpfr_print_binary (t); puts ("");
111                   exit (1);
112                 }
113             }
114         }
115     }
116 
117   mpfr_clear (s);
118   mpfr_clear (t);
119 
120   mpfr_clear (x);
121   mpfr_clear (y);
122   mpfr_clear (z);
123 
124   tests_end_mpfr ();
125   return 0;
126 }
127