1 /* Test mpfr_get_ld_2exp. 2 3 Copyright 2006-2018 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 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 <float.h> 24 25 #include "mpfr-test.h" 26 27 /* Check that hardware rounding doesn't make mpfr_get_ld_2exp return a value 28 outside its defined range. */ 29 static void 30 check_round (void) 31 { 32 static const unsigned long data[] = {1, 32, 53, 54, 63, 64, 65, 127, 128, 256, 512 }; 33 mpfr_t f; 34 long double got; 35 long got_exp; 36 int i, rnd_mode, neg; 37 38 mpfr_init2 (f, 1024L); 39 40 for (rnd_mode = 0; rnd_mode < MPFR_RND_MAX ; rnd_mode++) 41 { 42 for (i = 0; i < (int) numberof (data); i++) 43 { 44 mpfr_set_ui (f, 1L, MPFR_RNDZ); 45 mpfr_mul_2exp (f, f, data[i], MPFR_RNDZ); 46 mpfr_sub_ui (f, f, 1L, MPFR_RNDZ); 47 48 for (neg = 0; neg <= 1; neg++) 49 { 50 got = mpfr_get_ld_2exp (&got_exp, f, (mpfr_rnd_t) rnd_mode); 51 52 if (neg == 0 53 ? (got < 0.5 || got >= 1.0) 54 : (got <= -1.0 || got > -0.5)) 55 { 56 printf ("mpfr_get_ld_2exp wrong on 2**%lu-1\n", data[i]); 57 printf ("result out of range, expect 0.5 <= got < 1.0\n"); 58 printf (" rnd_mode = %d\n", rnd_mode); 59 printf (" data[i] = %lu\n", data[i]); 60 printf (" f "); 61 mpfr_out_str (stdout, 2, 0, f, MPFR_RNDN); 62 printf ("\n"); 63 d_trace (" got ", got); 64 printf (" got exp %ld\n", got_exp); 65 exit(1); 66 } 67 68 mpfr_neg (f, f, MPFR_RNDZ); 69 } 70 } 71 } 72 73 mpfr_clear (f); 74 } 75 76 77 static void 78 check_inf_nan (void) 79 { 80 #if !defined(MPFR_ERRDIVZERO) 81 mpfr_t x; 82 double d; 83 long exp; 84 85 mpfr_init2 (x, 123); 86 87 mpfr_set_inf (x, 1); 88 d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ); 89 MPFR_ASSERTN (d > 0); 90 MPFR_ASSERTN (DOUBLE_ISINF (d)); 91 92 mpfr_set_inf (x, -1); 93 d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ); 94 MPFR_ASSERTN (d < 0); 95 MPFR_ASSERTN (DOUBLE_ISINF (d)); 96 97 mpfr_set_nan (x); 98 d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ); 99 MPFR_ASSERTN (DOUBLE_ISNAN (d)); 100 101 mpfr_clear (x); 102 #endif 103 } 104 105 static void 106 bug20090520 (void) 107 { 108 mpfr_t x; 109 long double d, e; 110 int i; 111 112 mpfr_init (x); 113 mpfr_set_ui (x, 1, MPFR_RNDN); 114 d = 1.0; 115 mpfr_div_2exp (x, x, 16383, MPFR_RNDN); 116 for (i = 0; i < 16383; i++) 117 d *= 0.5; 118 e = mpfr_get_ld (x, MPFR_RNDN); 119 if (e != d) 120 { 121 printf ("mpfr_get_ld(1e-16383) failed\n"); 122 printf ("expected %.20Le\n", d); 123 printf ("got %.20Le\n", e); 124 exit (1); 125 } 126 mpfr_clear (x); 127 } 128 129 int 130 main (void) 131 { 132 tests_start_mpfr (); 133 mpfr_test_init (); 134 135 bug20090520 (); 136 137 check_round (); 138 check_inf_nan (); 139 140 tests_end_mpfr (); 141 return 0; 142 } 143