1 /* Test file for mpfr_ui_sub.
2
3 Copyright 2000-2023 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 <float.h>
24
25 #include "mpfr-test.h"
26
27 static void
28 special (void)
29 {
30 mpfr_t x, y, res;
31 int inexact;
32
33 mpfr_init (x);
34 mpfr_init (y);
35 mpfr_init (res);
36
37 mpfr_set_prec (x, 24);
38 mpfr_set_prec (y, 24);
39 mpfr_set_str_binary (y, "0.111100110001011010111");
40 inexact = mpfr_ui_sub (x, 1, y, MPFR_RNDN);
41 if (inexact)
42 {
43 printf ("Wrong inexact flag: got %d, expected 0\n", inexact);
44 exit (1);
45 }
46
47 mpfr_set_prec (x, 24);
48 mpfr_set_prec (y, 24);
49 mpfr_set_str_binary (y, "0.111100110001011010111");
50 if ((inexact = mpfr_ui_sub (x, 38181761, y, MPFR_RNDN)) >= 0)
51 {
52 printf ("Wrong inexact flag: got %d, expected -1\n", inexact);
53 exit (1);
54 }
55
56 mpfr_set_prec (x, 63);
57 mpfr_set_prec (y, 63);
58 mpfr_set_str_binary (y, "0.111110010010100100110101101010001001100101110001000101110111111E-1");
59 if ((inexact = mpfr_ui_sub (x, 1541116494, y, MPFR_RNDN)) <= 0)
60 {
61 printf ("Wrong inexact flag: got %d, expected +1\n", inexact);
62 exit (1);
63 }
64
65 mpfr_set_prec (x, 32);
66 mpfr_set_prec (y, 32);
67 mpfr_set_str_binary (y, "0.11011000110111010001011100011100E-1");
68 if ((inexact = mpfr_ui_sub (x, 2000375416, y, MPFR_RNDN)) >= 0)
69 {
70 printf ("Wrong inexact flag: got %d, expected -1\n", inexact);
71 exit (1);
72 }
73
74 mpfr_set_prec (x, 24);
75 mpfr_set_prec (y, 24);
76 mpfr_set_str_binary (y, "0.110011011001010011110111E-2");
77 if ((inexact = mpfr_ui_sub (x, 927694848, y, MPFR_RNDN)) <= 0)
78 {
79 printf ("Wrong inexact flag: got %d, expected +1\n", inexact);
80 exit (1);
81 }
82
83 /* bug found by Mathieu Dutour, 12 Apr 2001 */
84 mpfr_set_prec (x, 5);
85 mpfr_set_prec (y, 5);
86 mpfr_set_prec (res, 5);
87 mpfr_set_str_binary (x, "1e-12");
88
89 mpfr_ui_sub (y, 1, x, MPFR_RNDD);
90 mpfr_set_str_binary (res, "0.11111");
91 if (mpfr_cmp (y, res))
92 {
93 printf ("Error in mpfr_ui_sub (y, 1, x, MPFR_RNDD) for x=2^(-12)\nexpected 1.1111e-1, got ");
94 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN);
95 printf ("\n");
96 exit (1);
97 }
98
99 mpfr_ui_sub (y, 1, x, MPFR_RNDU);
100 mpfr_set_str_binary (res, "1.0");
101 if (mpfr_cmp (y, res))
102 {
103 printf ("Error in mpfr_ui_sub (y, 1, x, MPFR_RNDU) for x=2^(-12)\n"
104 "expected 1.0, got ");
105 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN);
106 printf ("\n");
107 exit (1);
108 }
109
110 mpfr_ui_sub (y, 1, x, MPFR_RNDN);
111 mpfr_set_str_binary (res, "1.0");
112 if (mpfr_cmp (y, res))
113 {
114 printf ("Error in mpfr_ui_sub (y, 1, x, MPFR_RNDN) for x=2^(-12)\n"
115 "expected 1.0, got ");
116 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN);
117 printf ("\n");
118 exit (1);
119 }
120
121 mpfr_set_prec (x, 10);
122 mpfr_set_prec (y, 10);
123 mpfr_urandomb (x, RANDS);
124 mpfr_ui_sub (y, 0, x, MPFR_RNDN);
125 if (MPFR_IS_ZERO(x))
126 MPFR_ASSERTN(MPFR_IS_ZERO(y));
127 else
128 MPFR_ASSERTN(mpfr_cmpabs (x, y) == 0 && mpfr_sgn (x) != mpfr_sgn (y));
129
130 mpfr_set_prec (x, 73);
131 mpfr_set_str_binary (x, "0.1101111010101011011011100011010000000101110001011111001011011000101111101E-99");
132 mpfr_ui_sub (x, 1, x, MPFR_RNDZ);
133 mpfr_nextabove (x);
134 MPFR_ASSERTN(mpfr_cmp_ui (x, 1) == 0);
135
136 mpfr_clear (x);
137 mpfr_clear (y);
138 mpfr_clear (res);
139 }
140
141 /* checks that (y-x) gives the right results with 53 bits of precision */
142 static void
143 check (unsigned long y, const char *xs, mpfr_rnd_t rnd_mode, const char *zs)
144 {
145 mpfr_t xx, zz;
146
147 mpfr_inits2 (53, xx, zz, (mpfr_ptr) 0);
148 mpfr_set_str1 (xx, xs);
149 mpfr_ui_sub (zz, y, xx, rnd_mode);
150 if (mpfr_cmp_str1 (zz, zs) )
151 {
152 printf ("expected difference is %s, got\n",zs);
153 mpfr_out_str(stdout, 10, 0, zz, MPFR_RNDN);
154 printf ("mpfr_ui_sub failed for y=%lu x=%s with rnd_mode=%s\n",
155 y, xs, mpfr_print_rnd_mode (rnd_mode));
156 exit (1);
157 }
158 mpfr_clears (xx, zz, (mpfr_ptr) 0);
159 }
160
161 /* if u = o(x-y), v = o(u-x), w = o(v+y), then x-y = u-w */
162 static void
163 check_two_sum (mpfr_prec_t p)
164 {
165 unsigned int x;
166 mpfr_t y, u, v, w;
167 mpfr_rnd_t rnd;
168 int inexact, cmp;
169
170 mpfr_inits2 (p, y, u, v, w, (mpfr_ptr) 0);
171 do
172 {
173 x = randlimb ();
174 }
175 while (x < 1);
176 mpfr_urandomb (y, RANDS);
177 rnd = MPFR_RNDN;
178 inexact = mpfr_ui_sub (u, x, y, rnd);
179 mpfr_sub_ui (v, u, x, rnd);
180 mpfr_add (w, v, y, rnd);
181 cmp = mpfr_cmp_ui (w, 0);
182 /* as u = (x-y) + w, we should have inexact and w of same sign */
183 if (! SAME_SIGN (inexact, cmp))
184 {
185 printf ("Wrong inexact flag for prec=%u, rnd=%s\n",
186 (unsigned int) p, mpfr_print_rnd_mode (rnd));
187 printf ("x = %u\n", x);
188 printf ("y = "); mpfr_dump (y);
189 printf ("u = "); mpfr_dump (u);
190 printf ("v = "); mpfr_dump (v);
191 printf ("w = "); mpfr_dump (w);
192 printf ("inexact = %d\n", inexact);
193 exit (1);
194 }
195 mpfr_clears (y, u, v, w, (mpfr_ptr) 0);
196 }
197
198 static void
199 check_nans (void)
200 {
201 mpfr_t x, y;
202
203 mpfr_init2 (x, 123L);
204 mpfr_init2 (y, 123L);
205
206 /* 1 - nan == nan */
207 mpfr_set_nan (x);
208 mpfr_ui_sub (y, 1L, x, MPFR_RNDN);
209 MPFR_ASSERTN (mpfr_nan_p (y));
210
211 /* 1 - +inf == -inf */
212 mpfr_set_inf (x, 1);
213 mpfr_ui_sub (y, 1L, x, MPFR_RNDN);
214 MPFR_ASSERTN (mpfr_inf_p (y));
215 MPFR_ASSERTN (mpfr_sgn (y) < 0);
216
217 /* 1 - -inf == +inf */
218 mpfr_set_inf (x, -1);
219 mpfr_ui_sub (y, 1L, x, MPFR_RNDN);
220 MPFR_ASSERTN (mpfr_inf_p (y));
221 MPFR_ASSERTN (mpfr_sgn (y) > 0);
222
223 mpfr_clear (x);
224 mpfr_clear (y);
225 }
226
227 /* Check mpfr_ui_sub with u = 0 (unsigned). */
228 static void check_neg (void)
229 {
230 mpfr_t x, yneg, ysub;
231 int i, s;
232 int r;
233
234 mpfr_init2 (x, 64);
235 mpfr_init2 (yneg, 32);
236 mpfr_init2 (ysub, 32);
237
238 for (i = 0; i <= 25; i++)
239 {
240 mpfr_sqrt_ui (x, i, MPFR_RNDN);
241 for (s = 0; s <= 1; s++)
242 {
243 RND_LOOP (r)
244 {
245 int tneg, tsub;
246
247 tneg = mpfr_neg (yneg, x, (mpfr_rnd_t) r);
248 tsub = mpfr_ui_sub (ysub, 0, x, (mpfr_rnd_t) r);
249 MPFR_ASSERTN (mpfr_equal_p (yneg, ysub));
250 MPFR_ASSERTN (!(MPFR_IS_POS (yneg) ^ MPFR_IS_POS (ysub)));
251 MPFR_ASSERTN (tneg == tsub);
252 }
253 mpfr_neg (x, x, MPFR_RNDN);
254 }
255 }
256
257 mpfr_clear (x);
258 mpfr_clear (yneg);
259 mpfr_clear (ysub);
260 }
261
262 static void
263 check_overflow (void)
264 {
265 mpfr_exp_t emin, emax;
266 mpfr_t x, y1, y2;
267 int inex1, inex2, rnd_mode;
268 mpfr_flags_t flags1, flags2;
269
270 emin = mpfr_get_emin ();
271 emax = mpfr_get_emax ();
272 set_emin (MPFR_EMIN_MIN);
273 set_emax (MPFR_EMAX_MAX);
274
275 mpfr_inits2 (32, x, y1, y2, (mpfr_ptr) 0);
276 mpfr_setmax (x, MPFR_EMAX_MAX);
277 mpfr_neg (x, x, MPFR_RNDN);
278 RND_LOOP_NO_RNDF (rnd_mode)
279 {
280 if (rnd_mode == MPFR_RNDU || rnd_mode == MPFR_RNDA)
281 {
282 inex1 = mpfr_overflow (y1, (mpfr_rnd_t) rnd_mode, 1);
283 flags1 = MPFR_FLAGS_OVERFLOW | MPFR_FLAGS_INEXACT;
284 }
285 else
286 {
287 mpfr_neg (y1, x, MPFR_RNDN);
288 inex1 = -1;
289 flags1 = MPFR_FLAGS_INEXACT;
290 }
291 mpfr_clear_flags ();
292 inex2 = mpfr_ui_sub (y2, 1, x, (mpfr_rnd_t) rnd_mode);
293 flags2 = __gmpfr_flags;
294 if (!(mpfr_equal_p (y1, y2) &&
295 SAME_SIGN (inex1, inex2) &&
296 flags1 == flags2))
297 {
298 printf ("Error in check_overflow for %s\n",
299 mpfr_print_rnd_mode ((mpfr_rnd_t) rnd_mode));
300 printf ("Expected ");
301 mpfr_dump (y1);
302 printf (" with inex = %d, flags =", inex1);
303 flags_out (flags1);
304 printf ("Got ");
305 mpfr_dump (y2);
306 printf (" with inex = %d, flags =", inex2);
307 flags_out (flags2);
308 exit (1);
309 }
310 }
311 mpfr_clears (x, y1, y2, (mpfr_ptr) 0);
312
313 set_emin (emin);
314 set_emax (emax);
315 }
316
317 #define TEST_FUNCTION mpfr_ui_sub
318 #define ULONG_ARG1
319 #include "tgeneric.c"
320
321 int
322 main (int argc, char *argv[])
323 {
324 mpfr_prec_t p;
325 unsigned k;
326
327 tests_start_mpfr ();
328
329 check_nans ();
330
331 special ();
332 for (p=2; p<100; p++)
333 for (k=0; k<100; k++)
334 check_two_sum (p);
335
336 check(1196426492, "1.4218093058435347e-3", MPFR_RNDN,
337 "1.1964264919985781e9");
338 check(1092583421, "-1.0880649218158844e9", MPFR_RNDN,
339 "2.1806483428158845901e9");
340 check(948002822, "1.22191250737771397120e+20", MPFR_RNDN,
341 "-1.2219125073682338611e20");
342 check(832100416, "4.68311314939691330000e-215", MPFR_RNDD,
343 "8.3210041599999988079e8");
344 check(1976245324, "1.25296395864546893357e+232", MPFR_RNDZ,
345 "-1.2529639586454686577e232");
346 check(2128997392, "-1.08496826129284207724e+187", MPFR_RNDU,
347 "1.0849682612928422704e187");
348 check(293607738, "-1.9967571564050541e-5", MPFR_RNDU,
349 "2.9360773800002003e8");
350 check(354270183, "2.9469161763489528e3", MPFR_RNDN,
351 "3.5426723608382362e8");
352 check_overflow ();
353
354 check_neg ();
355
356 test_generic (MPFR_PREC_MIN, 1000, 100);
357
358 tests_end_mpfr ();
359 return 0;
360 }