1/* Test file for mpfr_log_ui.
2
3Copyright 2016-2023 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
25static void
26compare_with_log (unsigned long n, mpfr_prec_t p)
27{
28  mpfr_t x, y;
29  int inex1, inex2;
30  mpfr_flags_t flags1;
31
32  mpfr_init2 (x, sizeof (unsigned long) * CHAR_BIT);
33  mpfr_init2 (y, p);
34  inex1 = mpfr_set_ui (x, n, MPFR_RNDN);
35  MPFR_ASSERTN(inex1 == 0);
36  inex1 = mpfr_log (y, x, MPFR_RNDN);
37  flags1 = __gmpfr_flags;
38  mpfr_set_prec (x, p);
39  inex2 = mpfr_log_ui (x, n, MPFR_RNDN);
40  MPFR_ASSERTN(inex1 == inex2);
41  MPFR_ASSERTN(flags1 == __gmpfr_flags);
42  MPFR_ASSERTN(mpfr_equal_p (x, y));
43  mpfr_clears (x, y, (mpfr_ptr) 0);
44}
45
46#define TEST_FUNCTION mpfr_log_ui
47#define ONE_ARG
48#define ULONG_ARG1
49#define RAND_FUNCTION(x) mpfr_set_ui (x, randlimb (), MPFR_RNDN)
50#include "tgeneric.c"
51
52#define TEST_FUNCTION mpfr_log_ui
53
54int
55main (int argc, char *argv[])
56{
57  unsigned int prec, yprec;
58  int rnd;
59  mpfr_t x, y, z, t, v;
60  unsigned long m, n;
61  int inex;
62  mpfr_exp_t emin, emax;
63  int i;
64
65  tests_start_mpfr ();
66
67  emin = mpfr_get_emin ();
68  emax = mpfr_get_emax ();
69
70  mpfr_inits2 (53, x, y, z, t, (mpfr_ptr) 0);
71  mpfr_init2 (v, sizeof (unsigned long) * CHAR_BIT);
72
73  if (argc >= 3) /* tlog_ui n prec [rnd] */
74    {
75      mpfr_set_prec (x, strtoul (argv[2], NULL, 10));
76      TEST_FUNCTION (x, strtoul (argv[1], NULL, 10),
77                    argc > 3 ? (mpfr_rnd_t) atoi (argv[3]) : MPFR_RNDN);
78      mpfr_out_str (stdout, 10, 0, x, MPFR_RNDN);
79      printf ("\n");
80      goto clear_and_exit;
81    }
82
83  mpfr_set_prec (x, 33);
84  mpfr_set_prec (y, 33);
85  mpfr_log_ui (x, 3, MPFR_RNDZ);
86  mpfr_set_str_binary (y, "1.0001100100111110101001111010101");
87  if (mpfr_cmp (x, y))
88    {
89      printf ("Error for log(3), prec=33, MPFR_RNDZ\n");
90      printf ("expected "); mpfr_dump (y);
91      printf ("got      "); mpfr_dump (x);
92      exit (1);
93    }
94
95  mpfr_set_prec (x, 60);
96  mpfr_set_prec (y, 60);
97  mpfr_log_ui (x, 19, MPFR_RNDU);
98  mpfr_set_str_binary (y, "10.1111000111000110110000001100000010010110011001011000111010");
99  if (mpfr_cmp (x, y))
100    {
101      printf ("Error for log(19), prec=60, MPFR_RNDU\n");
102      printf ("expected "); mpfr_dump (y);
103      printf ("got      "); mpfr_dump (x);
104      exit (1);
105    }
106
107  mpfr_clear_flags ();
108  inex = mpfr_log_ui (x, 0, MPFR_RNDN);
109  MPFR_ASSERTN (inex == 0);
110  MPFR_ASSERTN (mpfr_inf_p (x));
111  MPFR_ASSERTN (mpfr_sgn (x) < 0);
112  MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_DIVBY0);
113
114  mpfr_clear_flags ();
115  inex = mpfr_log_ui (x, 1, MPFR_RNDN);
116  MPFR_ASSERTN (inex == 0);
117  MPFR_ASSERTN (mpfr_zero_p (x));
118  MPFR_ASSERTN (mpfr_signbit (x) == 0);
119  MPFR_ASSERTN (__gmpfr_flags == 0);
120
121  for (prec = MPFR_PREC_MIN; prec <= 100; prec++)
122    {
123      mpfr_set_prec (x, prec);
124      mpfr_set_prec (z, prec);
125      mpfr_set_prec (t, prec);
126      yprec = prec + 20;
127      mpfr_set_prec (y, yprec);
128
129      for (m = 2; m < 130; m++)
130        RND_LOOP (rnd)
131          {
132            /* Start with n = 2 to 49 (mpfr_can_round would fail for n < 2),
133               then around ULONG_MAX/3, then around LONG_MAX, then
134               ULONG_MAX down to ULONG_MAX-19. */
135            n = (m < 50 ? m :
136                 m < 80 ? ULONG_MAX/3 + m - 65 :
137                 m < 110 ? (unsigned long) LONG_MAX + m - 95 :
138                 ULONG_MAX - (m - 110));
139            inex = mpfr_set_ui (v, n, MPFR_RNDN);
140            MPFR_ASSERTN (inex == 0);
141            mpfr_log (y, v, MPFR_RNDN);
142            if (mpfr_can_round (y, yprec, MPFR_RNDN, MPFR_RNDZ, prec
143                                + (rnd == MPFR_RNDN)))
144              {
145                mpfr_set (t, y, (mpfr_rnd_t) rnd);
146                for (i = 0; i <= 1; i++)
147                  {
148                    if (i)
149                      {
150                        mpfr_exp_t e;
151
152                        if (MPFR_IS_SINGULAR (t))
153                          break;
154                        e = mpfr_get_exp (t);
155                        set_emin (e);
156                        set_emax (e);
157                      }
158                    TEST_FUNCTION (z, n, (mpfr_rnd_t) rnd);
159                    if (i)
160                      {
161                        set_emin (emin);
162                        set_emax (emax);
163                      }
164                    if (mpfr_cmp (t, z))
165                      {
166                        printf ("results differ for n = %lu, prec = %u,"
167                                " %s%s\n", n, prec,
168                                mpfr_print_rnd_mode ((mpfr_rnd_t) rnd),
169                                i ? ", reduced exponent range" : "");
170                        printf ("  got      ");
171                        mpfr_dump (z);
172                        printf ("  expected ");
173                        mpfr_dump (t);
174                        printf ("  approx   ");
175                        mpfr_dump (y);
176                        exit (1);
177                      }
178                  }
179              }
180            else
181              {
182                /* We are not doing random tests. The precision increase
183                   must have be chosen so that this case never occurs. */
184                printf ("mpfr_can_round failed for n = %lu, prec = %u, %s\n",
185                        n, prec, mpfr_print_rnd_mode ((mpfr_rnd_t) rnd));
186                exit (1);
187              }
188          }
189    }
190
191
192  test_generic (MPFR_PREC_MIN, 1000, 1);
193
194  for (n = 1; n < ULONG_MAX / 3; n *= 3)
195    compare_with_log (n, 10);
196
197 clear_and_exit:
198  mpfr_clears (x, y, z, t, v, (mpfr_ptr) 0);
199
200  tests_end_mpfr ();
201  return 0;
202}
203