1/* Test file for mpfr_pow.
2
3Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
4Contributed by the Arenaire and Cacao 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
20http://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 <stdio.h>
24#include <limits.h>
25#include <stdlib.h>
26
27#include "mpfr-test.h"
28
29
30int
31main (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