1/* Test mpz_set_d and mpz_init_set_d. 2 3Copyright 2000, 2001, 2002, 2003, 2006 Free Software Foundation, Inc. 4 5This file is part of the GNU MP Library. 6 7The GNU MP Library is free software; you can redistribute it and/or modify 8it under the terms of the GNU Lesser General Public License as published by 9the Free Software Foundation; either version 3 of the License, or (at your 10option) any later version. 11 12The GNU MP Library is distributed in the hope that it will be useful, but 13WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15License for more details. 16 17You should have received a copy of the GNU Lesser General Public License 18along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 19 20#include <stdio.h> 21#include <stdlib.h> 22#include "gmp.h" 23#include "gmp-impl.h" 24#include "tests.h" 25 26 27void 28check_data (void) 29{ 30 static const struct { 31 double d; 32 mp_size_t want_size; 33 mp_limb_t want_data[2]; 34 } data[] = { 35 36 { 0.0, 0 }, 37 { 1.0, 1, { 1 } }, 38 { -1.0, -1, { 1 } }, 39 40 { 123.0, 1, { 123 } }, 41 { -123.0, -1, { 123 } }, 42 43 { 1e-1, 0, { 0 } }, 44 { -1e-1, 0, { 0 } }, 45 { 2.328306436538696e-10, 0, { 0 } }, 46 { -2.328306436538696e-10, 0, { 0 } }, 47 { 5.421010862427522e-20, 0, { 0 } }, 48 { -5.421010862427522e-20, 0, { 0 } }, 49 { 2.938735877055719e-39, 0, { 0 } }, 50 { -2.938735877055719e-39, 0, { 0 } }, 51 }; 52 53 mpz_t z; 54 int i; 55 56 for (i = 0; i < numberof (data); i++) 57 { 58 mpz_init (z); 59 mpz_set_d (z, data[i].d); 60 MPZ_CHECK_FORMAT (z); 61 if (z->_mp_size != data[i].want_size 62 || refmpn_cmp_allowzero (z->_mp_d, data[i].want_data, 63 ABS (data[i].want_size)) != 0) 64 { 65 printf ("mpz_set_d wrong on data[%d]\n", i); 66 bad: 67 d_trace (" d ", data[i].d); 68 printf (" got size %ld\n", (long) z->_mp_size); 69 printf (" want size %ld\n", (long) data[i].want_size); 70 mpn_trace (" got z", z->_mp_d, z->_mp_size); 71 mpn_trace (" want z", data[i].want_data, data[i].want_size); 72 abort(); 73 } 74 mpz_clear (z); 75 76 mpz_init_set_d (z, data[i].d); 77 MPZ_CHECK_FORMAT (z); 78 if (z->_mp_size != data[i].want_size 79 || refmpn_cmp_allowzero (z->_mp_d, data[i].want_data, 80 ABS (data[i].want_size)) != 0) 81 { 82 printf ("mpz_init_set_d wrong on data[%d]\n", i); 83 goto bad; 84 } 85 mpz_clear (z); 86 } 87} 88 89/* Try mpz_set_d on values 2^i+1, while such a value fits a double. */ 90void 91check_2n_plus_1 (void) 92{ 93 volatile double p, d, diff; 94 mpz_t want, got; 95 int i; 96 97 mpz_init (want); 98 mpz_init (got); 99 100 p = 1.0; 101 mpz_set_ui (want, 2L); /* gives 3 on first step */ 102 103 for (i = 1; i < 500; i++) 104 { 105 mpz_mul_2exp (want, want, 1L); 106 mpz_sub_ui (want, want, 1L); /* want = 2^i+1 */ 107 108 p *= 2.0; /* p = 2^i */ 109 d = p + 1.0; 110 diff = d - p; 111 if (diff != 1.0) 112 break; /* rounding occurred, stop now */ 113 114 mpz_set_d (got, d); 115 MPZ_CHECK_FORMAT (got); 116 if (mpz_cmp (got, want) != 0) 117 { 118 printf ("mpz_set_d wrong on 2^%d+1\n", i); 119 d_trace (" d ", d); 120 mpz_trace (" got ", got); 121 mpz_trace (" want ", want); 122 abort (); 123 } 124 } 125 126 mpz_clear (want); 127 mpz_clear (got); 128} 129 130int 131main (void) 132{ 133 tests_start (); 134 135 check_data (); 136 check_2n_plus_1 (); 137 138 tests_end (); 139 exit (0); 140} 141