1/* Test file for mpfr_pow.
2
3Copyright 2001-2023 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 "mpfr-test.h"
24
25
26int
27main (int argc, char *argv[])
28{
29  mpfr_t x, y, z;
30
31  mpfr_prec_t prec, yprec;
32  mpfr_t t, s;
33  mpfr_rnd_t rnd;
34  int inexact, compare, compare2;
35  unsigned int n, err;
36
37  mpfr_prec_t p0=2, p1=100;
38  unsigned int N=25;
39
40  tests_start_mpfr ();
41
42  mpfr_init (x);
43  mpfr_init2 (y,sizeof(unsigned long int)*CHAR_BIT);
44  mpfr_init (z);
45
46  mpfr_init (s);
47  mpfr_init (t);
48
49  /* generic test */
50  for (prec = p0; prec <= p1; prec++)
51    {
52      mpfr_set_prec (x, prec);
53      mpfr_set_prec (s, sizeof(unsigned long int)*CHAR_BIT);
54      mpfr_set_prec (z, prec);
55      mpfr_set_prec (t, prec);
56      yprec = prec + 10;
57
58      for (n=0; n<N; n++)
59        {
60          mpfr_urandomb (x, RANDS);
61          mpfr_urandomb (s, RANDS);
62          if (RAND_BOOL ())
63            mpfr_neg (s, s, MPFR_RNDN);
64          rnd = RND_RAND_NO_RNDF ();
65          mpfr_set_prec (y, yprec);
66          compare = mpfr_pow (y, x, s, rnd);
67          err = (rnd == MPFR_RNDN) ? yprec + 1 : yprec;
68          if (mpfr_can_round (y, err, rnd, rnd, prec))
69            {
70              mpfr_set (t, y, rnd);
71              inexact = mpfr_pow (z, x, s, rnd);
72              if (mpfr_cmp (t, z))
73                {
74                  printf ("results differ for x^y with\n");
75                  printf ("  x=");
76                  mpfr_dump (x);
77                  printf ("  y=");
78                  mpfr_dump (s);
79                  printf ("  with prec=%u rnd_mode=%s\n", (unsigned int) prec,
80                          mpfr_print_rnd_mode (rnd));
81                  printf ("got      ");
82                  mpfr_dump (z);
83                  printf ("expected ");
84                  mpfr_dump (t);
85                  printf ("approx   ");
86                  mpfr_dump (y);
87                  exit (1);
88                }
89              compare2 = mpfr_cmp (t, y);
90              /* if rounding to nearest, cannot know the sign of t - f(x)
91                 because of composed rounding: y = o(f(x)) and t = o(y) */
92              if ((rnd != MPFR_RNDN) && (compare * compare2 >= 0))
93                compare = compare + compare2;
94              else
95                compare = inexact; /* cannot determine sign(t-f(x)) */
96              if (((inexact == 0) && (compare != 0)) ||
97                  ((inexact > 0) && (compare <= 0)) ||
98                  ((inexact < 0) && (compare >= 0)))
99                {
100                  printf ("Wrong inexact flag for rnd=%s: expected %d, got %d"
101                          "\n", mpfr_print_rnd_mode (rnd), compare, inexact);
102                  printf ("x="); mpfr_dump (x);
103                  printf ("y="); mpfr_dump (y);
104                  printf ("t="); mpfr_dump (t);
105                  exit (1);
106                }
107            }
108        }
109    }
110
111  mpfr_clear (s);
112  mpfr_clear (t);
113
114  mpfr_clear (x);
115  mpfr_clear (y);
116  mpfr_clear (z);
117
118  tests_end_mpfr ();
119  return 0;
120}
121