xref: /netbsd-src/external/lgpl3/mpfr/dist/tests/tlog2p1.c (revision 8e33eff89e26cf71871ead62f0d5063e1313c33a)
1 /* Test file for mpfr_log2p1.
2 
3 Copyright 2001-2023 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 #define TEST_FUNCTION mpfr_log2p1
26 #define TEST_RANDOM_EMAX 80
27 #include "tgeneric.c"
28 
29 static void
30 special (void)
31 {
32   mpfr_t x;
33   int inex;
34 
35   mpfr_init2 (x, MPFR_PREC_MIN);
36 
37   mpfr_set_nan (x);
38   mpfr_clear_flags ();
39   inex = mpfr_log2p1 (x, x, MPFR_RNDN);
40   MPFR_ASSERTN (mpfr_nan_p (x) && inex == 0);
41   MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_NAN);
42 
43   mpfr_set_inf (x, -1);
44   mpfr_clear_flags ();
45   inex = mpfr_log2p1 (x, x, MPFR_RNDN);
46   MPFR_ASSERTN (mpfr_nan_p (x) && inex == 0);
47   MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_NAN);
48 
49   mpfr_set_inf (x, 1);
50   mpfr_clear_flags ();
51   inex = mpfr_log2p1 (x, x, MPFR_RNDN);
52   MPFR_ASSERTN (mpfr_inf_p (x) && mpfr_sgn (x) > 0 && inex == 0);
53   MPFR_ASSERTN (__gmpfr_flags == 0);
54 
55   mpfr_set_ui (x, 0, MPFR_RNDN);
56   mpfr_clear_flags ();
57   inex = mpfr_log2p1 (x, x, MPFR_RNDN);
58   MPFR_ASSERTN (mpfr_cmp_ui (x, 0) == 0 && MPFR_IS_POS (x) && inex == 0);
59   MPFR_ASSERTN (__gmpfr_flags == 0);
60   mpfr_neg (x, x, MPFR_RNDN);
61   mpfr_clear_flags ();
62   inex = mpfr_log2p1 (x, x, MPFR_RNDN);
63   MPFR_ASSERTN (mpfr_cmp_ui (x, 0) == 0 && MPFR_IS_NEG (x) && inex == 0);
64   MPFR_ASSERTN (__gmpfr_flags == 0);
65 
66   mpfr_set_si (x, -1, MPFR_RNDN);
67   mpfr_clear_flags ();
68   inex = mpfr_log2p1 (x, x, MPFR_RNDN);
69   MPFR_ASSERTN (mpfr_inf_p (x) && mpfr_sgn (x) < 0 && inex == 0);
70   MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_DIVBY0);
71 
72   mpfr_set_si (x, -2, MPFR_RNDN);
73   mpfr_clear_flags ();
74   inex = mpfr_log2p1 (x, x, MPFR_RNDN);
75   MPFR_ASSERTN (mpfr_nan_p (x) && inex == 0);
76   MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_NAN);
77 
78   /* include one hard-coded test */
79   mpfr_set_prec (x, 32);
80   mpfr_set_ui (x, 17, MPFR_RNDN);
81   inex = mpfr_log2p1 (x, x, MPFR_RNDN);
82   MPFR_ASSERTN (mpfr_cmp_ui_2exp (x, 1119355719UL, -28) == 0);
83   MPFR_ASSERTN (inex < 0);
84 
85   mpfr_clear (x);
86 }
87 
88 /* check exact cases, when 1+x = 2^k */
89 static void
90 check_exact (void)
91 {
92   mpfr_exp_t k;
93   mpfr_t x;
94   int inex, r;
95 
96 #define KMAX 100
97   mpfr_init2 (x, KMAX);
98   for (k = -KMAX; k <= KMAX; k++)
99     RND_LOOP (r)
100       {
101         mpfr_set_ui_2exp (x, 1, k, (mpfr_rnd_t) r);
102         inex = mpfr_sub_ui (x, x, 1, (mpfr_rnd_t) r);
103         MPFR_ASSERTN(inex == 0);
104         inex = mpfr_log2p1 (x, x, (mpfr_rnd_t) r);
105         MPFR_ASSERTN(mpfr_cmp_si0 (x, k) == 0);
106         MPFR_ASSERTN(inex == 0);
107       }
108   mpfr_clear (x);
109 }
110 
111 int
112 main (int argc, char *argv[])
113 {
114   tests_start_mpfr ();
115 
116   special ();
117 
118   check_exact ();
119 
120   test_generic (MPFR_PREC_MIN, 100, 50);
121 
122   tests_end_mpfr ();
123   return 0;
124 }
125