1 /* Test file for mpfr_ui_sub. 2 3 Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. 4 Contributed by the Arenaire and Cacao 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 http://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 <stdio.h> 24 #include <stdlib.h> 25 #include <float.h> 26 27 #include "mpfr-test.h" 28 29 static void 30 special (void) 31 { 32 mpfr_t x, y, res; 33 int inexact; 34 35 mpfr_init (x); 36 mpfr_init (y); 37 mpfr_init (res); 38 39 mpfr_set_prec (x, 24); 40 mpfr_set_prec (y, 24); 41 mpfr_set_str_binary (y, "0.111100110001011010111"); 42 inexact = mpfr_ui_sub (x, 1, y, MPFR_RNDN); 43 if (inexact) 44 { 45 printf ("Wrong inexact flag: got %d, expected 0\n", inexact); 46 exit (1); 47 } 48 49 mpfr_set_prec (x, 24); 50 mpfr_set_prec (y, 24); 51 mpfr_set_str_binary (y, "0.111100110001011010111"); 52 if ((inexact = mpfr_ui_sub (x, 38181761, y, MPFR_RNDN)) >= 0) 53 { 54 printf ("Wrong inexact flag: got %d, expected -1\n", inexact); 55 exit (1); 56 } 57 58 mpfr_set_prec (x, 63); 59 mpfr_set_prec (y, 63); 60 mpfr_set_str_binary (y, "0.111110010010100100110101101010001001100101110001000101110111111E-1"); 61 if ((inexact = mpfr_ui_sub (x, 1541116494, y, MPFR_RNDN)) <= 0) 62 { 63 printf ("Wrong inexact flag: got %d, expected +1\n", inexact); 64 exit (1); 65 } 66 67 mpfr_set_prec (x, 32); 68 mpfr_set_prec (y, 32); 69 mpfr_set_str_binary (y, "0.11011000110111010001011100011100E-1"); 70 if ((inexact = mpfr_ui_sub (x, 2000375416, y, MPFR_RNDN)) >= 0) 71 { 72 printf ("Wrong inexact flag: got %d, expected -1\n", inexact); 73 exit (1); 74 } 75 76 mpfr_set_prec (x, 24); 77 mpfr_set_prec (y, 24); 78 mpfr_set_str_binary (y, "0.110011011001010011110111E-2"); 79 if ((inexact = mpfr_ui_sub (x, 927694848, y, MPFR_RNDN)) <= 0) 80 { 81 printf ("Wrong inexact flag: got %d, expected +1\n", inexact); 82 exit (1); 83 } 84 85 /* bug found by Mathieu Dutour, 12 Apr 2001 */ 86 mpfr_set_prec (x, 5); 87 mpfr_set_prec (y, 5); 88 mpfr_set_prec (res, 5); 89 mpfr_set_str_binary (x, "1e-12"); 90 91 mpfr_ui_sub (y, 1, x, MPFR_RNDD); 92 mpfr_set_str_binary (res, "0.11111"); 93 if (mpfr_cmp (y, res)) 94 { 95 printf ("Error in mpfr_ui_sub (y, 1, x, MPFR_RNDD) for x=2^(-12)\nexpected 1.1111e-1, got "); 96 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN); 97 printf ("\n"); 98 exit (1); 99 } 100 101 mpfr_ui_sub (y, 1, x, MPFR_RNDU); 102 mpfr_set_str_binary (res, "1.0"); 103 if (mpfr_cmp (y, res)) 104 { 105 printf ("Error in mpfr_ui_sub (y, 1, x, MPFR_RNDU) for x=2^(-12)\n" 106 "expected 1.0, got "); 107 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN); 108 printf ("\n"); 109 exit (1); 110 } 111 112 mpfr_ui_sub (y, 1, x, MPFR_RNDN); 113 mpfr_set_str_binary (res, "1.0"); 114 if (mpfr_cmp (y, res)) 115 { 116 printf ("Error in mpfr_ui_sub (y, 1, x, MPFR_RNDN) for x=2^(-12)\n" 117 "expected 1.0, got "); 118 mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN); 119 printf ("\n"); 120 exit (1); 121 } 122 123 mpfr_set_prec (x, 10); 124 mpfr_set_prec (y, 10); 125 mpfr_urandomb (x, RANDS); 126 mpfr_ui_sub (y, 0, x, MPFR_RNDN); 127 if (MPFR_IS_ZERO(x)) 128 MPFR_ASSERTN(MPFR_IS_ZERO(y)); 129 else 130 MPFR_ASSERTN(mpfr_cmpabs (x, y) == 0 && mpfr_sgn (x) != mpfr_sgn (y)); 131 132 mpfr_set_prec (x, 73); 133 mpfr_set_str_binary (x, "0.1101111010101011011011100011010000000101110001011111001011011000101111101E-99"); 134 mpfr_ui_sub (x, 1, x, MPFR_RNDZ); 135 mpfr_nextabove (x); 136 MPFR_ASSERTN(mpfr_cmp_ui (x, 1) == 0); 137 138 mpfr_clear (x); 139 mpfr_clear (y); 140 mpfr_clear (res); 141 } 142 143 /* checks that (y-x) gives the right results with 53 bits of precision */ 144 static void 145 check (unsigned long y, const char *xs, mpfr_rnd_t rnd_mode, const char *zs) 146 { 147 mpfr_t xx, zz; 148 149 mpfr_inits2 (53, xx, zz, (mpfr_ptr) 0); 150 mpfr_set_str1 (xx, xs); 151 mpfr_ui_sub (zz, y, xx, rnd_mode); 152 if (mpfr_cmp_str1 (zz, zs) ) 153 { 154 printf ("expected difference is %s, got\n",zs); 155 mpfr_out_str(stdout, 10, 0, zz, MPFR_RNDN); 156 printf ("mpfr_ui_sub failed for y=%lu x=%s with rnd_mode=%s\n", 157 y, xs, mpfr_print_rnd_mode (rnd_mode)); 158 exit (1); 159 } 160 mpfr_clears (xx, zz, (mpfr_ptr) 0); 161 } 162 163 /* if u = o(x-y), v = o(u-x), w = o(v+y), then x-y = u-w */ 164 static void 165 check_two_sum (mpfr_prec_t p) 166 { 167 unsigned int x; 168 mpfr_t y, u, v, w; 169 mpfr_rnd_t rnd; 170 int inexact; 171 172 mpfr_inits2 (p, y, u, v, w, (mpfr_ptr) 0); 173 do 174 { 175 x = randlimb (); 176 } 177 while (x < 1); 178 mpfr_urandomb (y, RANDS); 179 rnd = MPFR_RNDN; 180 inexact = mpfr_ui_sub (u, x, y, rnd); 181 mpfr_sub_ui (v, u, x, rnd); 182 mpfr_add (w, v, y, rnd); 183 /* as u = (x-y) + w, we should have inexact and w of same sign */ 184 if (((inexact == 0) && mpfr_cmp_ui (w, 0)) || 185 ((inexact > 0) && (mpfr_cmp_ui (w, 0) <= 0)) || 186 ((inexact < 0) && (mpfr_cmp_ui (w, 0) >= 0))) 187 { 188 printf ("Wrong inexact flag for prec=%u, rnd=%s\n", 189 (unsigned int) p, mpfr_print_rnd_mode (rnd)); 190 printf ("x=%u\n", x); 191 printf ("y="); mpfr_print_binary(y); puts (""); 192 printf ("u="); mpfr_print_binary(u); puts (""); 193 printf ("v="); mpfr_print_binary(v); puts (""); 194 printf ("w="); mpfr_print_binary(w); puts (""); 195 printf ("inexact = %d\n", inexact); 196 exit (1); 197 } 198 mpfr_clears (y, u, v, w, (mpfr_ptr) 0); 199 } 200 201 static void 202 check_nans (void) 203 { 204 mpfr_t x, y; 205 206 mpfr_init2 (x, 123L); 207 mpfr_init2 (y, 123L); 208 209 /* 1 - nan == nan */ 210 mpfr_set_nan (x); 211 mpfr_ui_sub (y, 1L, x, MPFR_RNDN); 212 MPFR_ASSERTN (mpfr_nan_p (y)); 213 214 /* 1 - +inf == -inf */ 215 mpfr_set_inf (x, 1); 216 mpfr_ui_sub (y, 1L, x, MPFR_RNDN); 217 MPFR_ASSERTN (mpfr_inf_p (y)); 218 MPFR_ASSERTN (mpfr_sgn (y) < 0); 219 220 /* 1 - -inf == +inf */ 221 mpfr_set_inf (x, -1); 222 mpfr_ui_sub (y, 1L, x, MPFR_RNDN); 223 MPFR_ASSERTN (mpfr_inf_p (y)); 224 MPFR_ASSERTN (mpfr_sgn (y) > 0); 225 226 mpfr_clear (x); 227 mpfr_clear (y); 228 } 229 230 /* Check mpfr_ui_sub with u = 0 (unsigned). */ 231 static void check_neg (void) 232 { 233 mpfr_t x, yneg, ysub; 234 int i, s; 235 int r; 236 237 mpfr_init2 (x, 64); 238 mpfr_init2 (yneg, 32); 239 mpfr_init2 (ysub, 32); 240 241 for (i = 0; i <= 25; i++) 242 { 243 mpfr_sqrt_ui (x, i, MPFR_RNDN); 244 for (s = 0; s <= 1; s++) 245 { 246 RND_LOOP (r) 247 { 248 int tneg, tsub; 249 250 tneg = mpfr_neg (yneg, x, (mpfr_rnd_t) r); 251 tsub = mpfr_ui_sub (ysub, 0, x, (mpfr_rnd_t) r); 252 MPFR_ASSERTN (mpfr_equal_p (yneg, ysub)); 253 MPFR_ASSERTN (!(MPFR_IS_POS (yneg) ^ MPFR_IS_POS (ysub))); 254 MPFR_ASSERTN (tneg == tsub); 255 } 256 mpfr_neg (x, x, MPFR_RNDN); 257 } 258 } 259 260 mpfr_clear (x); 261 mpfr_clear (yneg); 262 mpfr_clear (ysub); 263 } 264 265 int 266 main (int argc, char *argv[]) 267 { 268 mpfr_prec_t p; 269 unsigned k; 270 271 tests_start_mpfr (); 272 273 check_nans (); 274 275 special (); 276 for (p=2; p<100; p++) 277 for (k=0; k<100; k++) 278 check_two_sum (p); 279 280 check(1196426492, "1.4218093058435347e-3", MPFR_RNDN, 281 "1.1964264919985781e9"); 282 check(1092583421, "-1.0880649218158844e9", MPFR_RNDN, 283 "2.1806483428158845901e9"); 284 check(948002822, "1.22191250737771397120e+20", MPFR_RNDN, 285 "-1.2219125073682338611e20"); 286 check(832100416, "4.68311314939691330000e-215", MPFR_RNDD, 287 "8.3210041599999988079e8"); 288 check(1976245324, "1.25296395864546893357e+232", MPFR_RNDZ, 289 "-1.2529639586454686577e232"); 290 check(2128997392, "-1.08496826129284207724e+187", MPFR_RNDU, 291 "1.0849682612928422704e187"); 292 check(293607738, "-1.9967571564050541e-5", MPFR_RNDU, 293 "2.9360773800002003e8"); 294 check(354270183, "2.9469161763489528e3", MPFR_RNDN, 295 "3.5426723608382362e8"); 296 297 check_neg (); 298 299 tests_end_mpfr (); 300 return 0; 301 } 302