xref: /netbsd-src/external/lgpl3/mpfr/dist/tests/texp10m1.c (revision ba125506a622fe649968631a56eba5d42ff57863)
1 /* Test file for mpfr_exp10m1.
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_exp10m1
26 #define TEST_RANDOM_EMIN -36
27 #define TEST_RANDOM_EMAX 36
28 #include "tgeneric.c"
29 
30 static void
special(void)31 special (void)
32 {
33   mpfr_t x, y;
34   int i;
35 
36   mpfr_init2 (x, 2);
37   mpfr_init2 (y, 2);
38 
39   mpfr_set_nan (x);
40   mpfr_exp10m1 (y, x, MPFR_RNDN);
41   if (!mpfr_nan_p (y))
42     {
43       printf ("Error for exp10m1(NaN)\n");
44       exit (1);
45     }
46 
47   mpfr_set_inf (x, 1);
48   mpfr_exp10m1 (y, x, MPFR_RNDN);
49   if (!mpfr_inf_p (y) || mpfr_sgn (y) < 0)
50     {
51       printf ("Error for exp10m1(+Inf)\n");
52       exit (1);
53     }
54 
55   mpfr_set_inf (x, -1);
56   mpfr_exp10m1 (y, x, MPFR_RNDN);
57   if (mpfr_cmp_si (y, -1) != 0)
58     {
59       printf ("Error for exp10m1(-Inf)\n");
60       exit (1);
61     }
62 
63   mpfr_set_ui (x, 0, MPFR_RNDN);
64   mpfr_exp10m1 (y, x, MPFR_RNDN);
65   if (MPFR_NOTZERO (y) || MPFR_IS_NEG (y))
66     {
67       printf ("Error for exp10m1(+0)\n");
68       exit (1);
69     }
70 
71   mpfr_neg (x, x, MPFR_RNDN);
72   mpfr_exp10m1 (y, x, MPFR_RNDN);
73   if (MPFR_NOTZERO (y) || MPFR_IS_POS (y))
74     {
75       printf ("Error for exp10m1(-0)\n");
76       exit (1);
77     }
78 
79   /* Check overflow of exp10m1(x) */
80   mpfr_clear_flags ();
81   mpfr_set_str_binary (x, "1.1E1000000000");
82   i = mpfr_exp10m1 (x, x, MPFR_RNDN);
83   MPFR_ASSERTN (MPFR_IS_INF (x) && MPFR_IS_POS (x));
84   MPFR_ASSERTN (mpfr_overflow_p ());
85   MPFR_ASSERTN (i > 0);
86 
87   mpfr_clear_flags ();
88   mpfr_set_str_binary (x, "1.1E1000000000");
89   i = mpfr_exp10m1 (x, x, MPFR_RNDU);
90   MPFR_ASSERTN (MPFR_IS_INF (x) && MPFR_IS_POS (x));
91   MPFR_ASSERTN (mpfr_overflow_p ());
92   MPFR_ASSERTN (i > 0);
93 
94   mpfr_clear_flags ();
95   mpfr_set_str_binary (x, "1.1E1000000000");
96   i = mpfr_exp10m1 (x, x, MPFR_RNDD);
97   MPFR_ASSERTN (!MPFR_IS_INF (x) && MPFR_IS_POS (x));
98   MPFR_ASSERTN (mpfr_overflow_p ());
99   MPFR_ASSERTN (i < 0);
100 
101   /* Check internal underflow of exp10m1 (x) */
102   mpfr_set_prec (x, 2);
103   mpfr_clear_flags ();
104   mpfr_set_str_binary (x, "-1.1E1000000000");
105   i = mpfr_exp10m1 (x, x, MPFR_RNDN);
106   MPFR_ASSERTN (mpfr_cmp_si (x, -1) == 0);
107   MPFR_ASSERTN (!mpfr_overflow_p () && !mpfr_underflow_p ());
108   MPFR_ASSERTN (i < 0);
109 
110   mpfr_set_str_binary (x, "-1.1E1000000000");
111   i = mpfr_exp10m1 (x, x, MPFR_RNDD);
112   MPFR_ASSERTN (mpfr_cmp_si (x, -1) == 0);
113   MPFR_ASSERTN (!mpfr_overflow_p () && !mpfr_underflow_p ());
114   MPFR_ASSERTN (i < 0);
115 
116   mpfr_set_str_binary (x, "-1.1E1000000000");
117   i = mpfr_exp10m1 (x, x, MPFR_RNDZ);
118   MPFR_ASSERTN (mpfr_cmp_str (x, "-0.11", 2, MPFR_RNDN) == 0);
119   MPFR_ASSERTN (!mpfr_overflow_p () && !mpfr_underflow_p ());
120   MPFR_ASSERTN (i > 0);
121 
122   mpfr_set_str_binary (x, "-1.1E1000000000");
123   i = mpfr_exp10m1 (x, x, MPFR_RNDU);
124   MPFR_ASSERTN (mpfr_cmp_str (x, "-0.11", 2, MPFR_RNDN) == 0);
125   MPFR_ASSERTN (!mpfr_overflow_p () && !mpfr_underflow_p ());
126   MPFR_ASSERTN (i > 0);
127 
128   /* hard-coded test */
129   mpfr_set_prec (x, 32);
130   mpfr_set_prec (y, 32);
131   mpfr_set_ui_2exp (x, 1686629713UL, -29, MPFR_RNDN); /* approximates Pi */
132   i = mpfr_exp10m1 (y, x, MPFR_RNDN);
133   MPFR_ASSERTN (mpfr_cmp_ui_2exp (y, 2903414105UL, -21) == 0);
134   MPFR_ASSERTN (i < 0);
135 
136   mpfr_clear (x);
137   mpfr_clear (y);
138 }
139 
140 /* test integer x, 1 <= x <= 64, where 10^x-1 is exact */
141 static void
test_exact(void)142 test_exact (void)
143 {
144   long k;
145   mpfr_t x, y, z;
146   mpz_t n;
147   mpfr_prec_t p;
148   int i, j, r;
149 
150   mpfr_init2 (x, 6); /* enough to represent exactly all integers <= 64 */
151   mpfr_init2 (y, MPFR_PREC_MIN);
152   mpfr_init2 (z, MPFR_PREC_MIN);
153   mpz_init_set_ui (n, 9);
154   for (k = 1; k <= 64; k++)
155     {
156       /* invariant: n = 10^k-1 */
157       /* 10^64 needs 213 bits */
158       for (p = MPFR_PREC_MIN; p <= 213; p++)
159         {
160           mpfr_set_prec (y, p);
161           mpfr_set_prec (z, p);
162           mpfr_set_si (x, k, MPFR_RNDN);
163           /* for RNDF, result may differ */
164           RND_LOOP_NO_RNDF(r)
165             {
166               i = mpfr_exp10m1 (y, x, (mpfr_rnd_t) r);
167               j = mpfr_set_z (z, n, (mpfr_rnd_t) r);
168               if (!mpfr_equal_p (y, z))
169                 {
170                   printf ("Error for mpfr_exp10m1, x=%ld, rnd=%s\n", k,
171                           mpfr_print_rnd_mode ((mpfr_rnd_t) r));
172                   printf ("expected "); mpfr_dump (z);
173                   printf ("got      "); mpfr_dump (y);
174                   exit (1);
175                 }
176               if ((i == 0 && j != 0) || (i != 0 && j == 0) || (i * j < 0))
177                 {
178                   printf ("Bar ternary value for mpfr_exp10m1, x=%ld, rnd=%s\n",
179                           k, mpfr_print_rnd_mode ((mpfr_rnd_t) r));
180                   printf ("expected %d\n", j);
181                   printf ("got      %d\n", i);
182                   exit (1);
183                 }
184             }
185         }
186       mpz_mul_ui (n, n, 10);
187       mpz_add_ui (n, n, 9);
188     }
189   mpfr_clear (x);
190   mpfr_clear (y);
191   mpfr_clear (z);
192   mpz_clear (n);
193 }
194 
195 int
main(int argc,char * argv[])196 main (int argc, char *argv[])
197 {
198   tests_start_mpfr ();
199 
200   special ();
201 
202   test_exact ();
203 
204   test_generic (MPFR_PREC_MIN, 100, 100);
205 
206   tests_end_mpfr ();
207   return 0;
208 }
209