xref: /netbsd-src/external/lgpl3/mpfr/dist/tests/tai.c (revision ba125506a622fe649968631a56eba5d42ff57863)
1 /* Test file for mpfr_ai.
2 
3 Copyright 2010-2023 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_ai
26 #define TEST_RANDOM_EMIN -5
27 #define TEST_RANDOM_EMAX 5
28 #define REDUCE_EMAX 7 /* this is to avoid that test_generic() calls mpfr_ai
29                          with too large inputs. FIXME: remove this once
30                          mpfr_ai can handle large inputs */
31 #include "tgeneric.c"
32 
33 static void
check_large(void)34 check_large (void)
35 {
36   mpfr_t x, y, z;
37 
38   mpfr_init2 (x, 38);
39   mpfr_init2 (y, 110);
40   mpfr_init2 (z, 110);
41   mpfr_set_str_binary (x, "-1E8");
42   mpfr_ai (y, x, MPFR_RNDN);
43   mpfr_set_str_binary (z, "-10001110100001011111110001100011101100011100010000110100100101011111011100000101110101010010000000101110011111E-112");
44   if (mpfr_equal_p (y, z) == 0)
45     {
46       printf ("Error in mpfr_ai for x=-2^8\n");
47       exit (1);
48     }
49 #if 0 /* disabled since mpfr_ai does not currently handle large arguments */
50   mpfr_set_str_binary (x, "-1E26");
51   mpfr_ai (y, x, MPFR_RNDN);
52   mpfr_set_str_binary (z, "-110001111100000011001010010101001101001011001011101011001010100100001110001101101101000010000011001000001011E-118");
53   if (mpfr_equal_p (y, z) == 0)
54     {
55       printf ("Error in mpfr_ai for x=-2^26\n");
56       exit (1);
57     }
58   mpfr_set_str_binary (x, "-0.11111111111111111111111111111111111111E1073741823");
59   mpfr_ai (y, x, MPFR_RNDN);
60   /* FIXME: compute the correctly rounded value we should get for Ai(x),
61      and check we get this value */
62 #endif
63   mpfr_clear (x);
64   mpfr_clear (y);
65   mpfr_clear (z);
66 }
67 
68 static void
check_zero(void)69 check_zero (void)
70 {
71   mpfr_t x, y, r;
72 
73   mpfr_init2 (x, 53);
74   mpfr_init2 (y, 53);
75   mpfr_init2 (r, 53);
76 
77   mpfr_set_str_binary (r, "10110101110001100011110010110001001110001010110111E-51");
78 
79   mpfr_set_ui (x, 0, MPFR_RNDN);
80   mpfr_ai (y, x, MPFR_RNDN);
81   if (mpfr_equal_p (y, r) == 0)
82     {
83       printf ("Error in mpfr_ai for x=0\n");
84       printf ("Expected "); mpfr_dump (r);
85       printf ("Got      "); mpfr_dump (y);
86       exit (1);
87     }
88   mpfr_clear (x);
89   mpfr_clear (y);
90   mpfr_clear (r);
91 }
92 
93 static void
bug20180107(void)94 bug20180107 (void)
95 {
96   mpfr_t x, y, z;
97   mpfr_exp_t emin;
98   int inex;
99   mpfr_flags_t flags;
100 
101   mpfr_init2 (x, 152);
102   mpfr_init2 (y, 11);
103   mpfr_init2 (z, 11);
104   mpfr_set_str_binary (x, "0.11010101100111000111001001010110101001100001011110101111000010100111011101011110000100111011101100100100001010000110100011001000111010010001110000011100E5");
105   emin = mpfr_get_emin ();
106   set_emin (-134);
107   mpfr_clear_flags ();
108   inex = mpfr_ai (y, x, MPFR_RNDA);
109   flags = __gmpfr_flags;
110   /* result should be 0.10011100000E-135 with unlimited exponent range,
111      and thus should be rounded to 0.1E-134 */
112   mpfr_set_str_binary (z, "0.1E-134");
113   MPFR_ASSERTN (mpfr_equal_p (y, z));
114   MPFR_ASSERTN (inex > 0);
115   MPFR_ASSERTN (flags == (MPFR_FLAGS_UNDERFLOW | MPFR_FLAGS_INEXACT));
116 
117   mpfr_set_prec (x, 2);
118   mpfr_set_str_binary (x, "0.11E7");
119   mpfr_set_prec (y, 2);
120   mpfr_clear_flags ();
121   inex = mpfr_ai (y, x, MPFR_RNDA);
122   flags = __gmpfr_flags;
123   /* result should be 1.0E-908 with unlimited exponent range,
124      and thus should be rounded to 0.1E-134 */
125   mpfr_set_str_binary (z, "0.1E-134");
126   MPFR_ASSERTN (mpfr_equal_p (y, z));
127   MPFR_ASSERTN (inex > 0);
128   MPFR_ASSERTN (flags == (MPFR_FLAGS_UNDERFLOW | MPFR_FLAGS_INEXACT));
129 
130   set_emin (emin);
131   mpfr_clear (x);
132   mpfr_clear (y);
133   mpfr_clear (z);
134 }
135 
136 /* exercise mpfr_ai near m*2^e, for precision p */
137 static void
test_near_m2e(long m,mpfr_exp_t e,mpfr_prec_t pmax)138 test_near_m2e (long m, mpfr_exp_t e, mpfr_prec_t pmax)
139 {
140   mpfr_t x, xx, y, yy;
141   mpfr_prec_t p;
142   int inex;
143 
144   mpfr_clear_flags ();
145 
146   /* first determine the smallest precision for which m*2^e is exact */
147   for (p = MPFR_PREC_MIN; p <= pmax; p++)
148     {
149       mpfr_init2 (x, p);
150       inex = mpfr_set_si_2exp (x, m, e, MPFR_RNDN);
151       mpfr_clear (x);
152       if (inex == 0)
153         break;
154     }
155 
156   mpfr_init2 (x, p);
157   inex = mpfr_set_si_2exp (x, m, e, MPFR_RNDN);
158   MPFR_ASSERTN(inex == 0);
159 
160   for (; p <= pmax; p++)
161     {
162       mpfr_init2 (y, p);
163       mpfr_init2 (xx, p);
164       mpfr_init2 (yy, p);
165       mpfr_prec_round (x, p, MPFR_RNDN);
166       mpfr_ai (y, x, MPFR_RNDN);
167       while (1)
168         {
169           mpfr_set (xx, x, MPFR_RNDN);
170           mpfr_nextbelow (xx);
171           mpfr_ai (yy, xx, MPFR_RNDN);
172           if (mpfr_cmpabs (yy, y) >= 0)
173             break;
174           else
175             {
176               mpfr_set (x, xx, MPFR_RNDN);
177               mpfr_set (y, yy, MPFR_RNDN);
178             }
179         }
180       while (1)
181         {
182           mpfr_set (xx, x, MPFR_RNDN);
183           mpfr_nextabove (xx);
184           mpfr_ai (yy, xx, MPFR_RNDN);
185           if (mpfr_cmpabs (yy, y) >= 0)
186             break;
187           else
188             {
189               mpfr_set (x, xx, MPFR_RNDN);
190               mpfr_set (y, yy, MPFR_RNDN);
191             }
192         }
193       mpfr_clear (y);
194       mpfr_clear (xx);
195       mpfr_clear (yy);
196     }
197 
198   mpfr_clear (x);
199 
200   /* Since some tests don't really check that the result is not NaN... */
201   MPFR_ASSERTN (! mpfr_nanflag_p ());
202 }
203 
204 /* example provided by Sylvain Chevillard, which exercises the case
205    wprec < err + 1, and thus correct_bits = 0, in src/ai.c */
206 static void
coverage(void)207 coverage (void)
208 {
209   mpfr_t x, y;
210   int inex;
211 
212   mpfr_init2 (x, 800);
213   mpfr_init2 (y, 20);
214   mpfr_set_str (x, "-2.3381074104597670384891972524467354406385401456723878524838544372136680027002836477821640417313293202847600938532659527752254668583598667448688987168197275409731526749911127480659996456283534915503672", 10, MPFR_RNDN);
215   inex = mpfr_ai (y, x, MPFR_RNDN);
216   MPFR_ASSERTN(inex < 0);
217   MPFR_ASSERTN(mpfr_cmp_ui_2exp (y, 593131, -682) == 0);
218 
219   mpfr_clear (x);
220   mpfr_clear (y);
221 }
222 
223 int
main(int argc,char * argv[])224 main (int argc, char *argv[])
225 {
226   tests_start_mpfr ();
227 
228   coverage ();
229   test_near_m2e (-5, -1, 100); /* exercise near -2.5 */
230   test_near_m2e (-4, 0, 100); /* exercise near -4 */
231   test_near_m2e (-11, -1, 100); /* exercise near -5.5 */
232   test_near_m2e (-27, -2, 100); /* exercise near -6.75 */
233   test_near_m2e (-31, -2, 100); /* exercise near -7.75 */
234   test_near_m2e (-15, -1, 100); /* exercise near -7.5 */
235   bug20180107 ();
236   check_large ();
237   check_zero ();
238 
239   test_generic (MPFR_PREC_MIN, 100, 5);
240 
241   tests_end_mpfr ();
242   return 0;
243 }
244