xref: /netbsd-src/external/lgpl3/mpfr/dist/tests/tlog_ui.c (revision ba125506a622fe649968631a56eba5d42ff57863)
1 /* Test file for mpfr_log_ui.
2 
3 Copyright 2016-2023 Free Software Foundation, Inc.
4 Contributed by the AriC and Caramba 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 https://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 "mpfr-test.h"
24 
25 static void
compare_with_log(unsigned long n,mpfr_prec_t p)26 compare_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 
54 int
main(int argc,char * argv[])55 main (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