1 /* Test mpf_get_d_2exp. 2 3 Copyright 2002, 2003 Free Software Foundation, Inc. 4 5 This file is part of the GNU MP Library test suite. 6 7 The GNU MP Library test suite is free software; you can redistribute it 8 and/or modify it under the terms of the GNU General Public License as 9 published by the Free Software Foundation; either version 3 of the License, 10 or (at your option) any later version. 11 12 The GNU MP Library test suite is distributed in the hope that it will be 13 useful, but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 15 Public License for more details. 16 17 You should have received a copy of the GNU General Public License along with 18 the GNU MP Library test suite. 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 27 static void 28 check_onebit (void) 29 { 30 static const long data[] = { 31 -513, -512, -511, -65, -64, -63, -32, -1, 32 0, 1, 32, 53, 54, 64, 128, 256, 511, 512, 513 33 }; 34 mpf_t f; 35 double got, want; 36 long got_exp, want_exp; 37 int i; 38 39 mpf_init2 (f, 1024L); 40 41 for (i = 0; i < numberof (data); i++) 42 { 43 mpf_set_ui (f, 1L); 44 if (data[i] >= 0) 45 mpf_mul_2exp (f, f, data[i]); 46 else 47 mpf_div_2exp (f, f, -data[i]); 48 want = 0.5; 49 want_exp = data[i] + 1; 50 51 got = mpf_get_d_2exp (&got_exp, f); 52 if (got != want || got_exp != want_exp) 53 { 54 printf ("mpf_get_d_2exp wrong on 2**%ld\n", data[i]); 55 mpf_trace (" f ", f); 56 d_trace (" want ", want); 57 d_trace (" got ", got); 58 printf (" want exp %ld\n", want_exp); 59 printf (" got exp %ld\n", got_exp); 60 abort(); 61 } 62 } 63 mpf_clear (f); 64 } 65 66 /* Check that hardware rounding doesn't make mpf_get_d_2exp return a value 67 outside its defined range. */ 68 static void 69 check_round (void) 70 { 71 static const unsigned long data[] = { 1, 32, 53, 54, 64, 128, 256, 512 }; 72 mpf_t f; 73 double got; 74 long got_exp; 75 int i, rnd_mode, old_rnd_mode; 76 77 mpf_init2 (f, 1024L); 78 old_rnd_mode = tests_hardware_getround (); 79 80 for (rnd_mode = 0; rnd_mode < 4; rnd_mode++) 81 { 82 tests_hardware_setround (rnd_mode); 83 84 for (i = 0; i < numberof (data); i++) 85 { 86 mpf_set_ui (f, 1L); 87 mpf_mul_2exp (f, f, data[i]); 88 mpf_sub_ui (f, f, 1L); 89 90 got = mpf_get_d_2exp (&got_exp, f); 91 if (got < 0.5 || got >= 1.0) 92 { 93 printf ("mpf_get_d_2exp bad on 2**%lu-1\n", data[i]); 94 printf ("result out of range, expect 0.5 <= got < 1.0\n"); 95 printf (" rnd_mode = %d\n", rnd_mode); 96 printf (" data[i] = %lu\n", data[i]); 97 mpf_trace (" f ", f); 98 d_trace (" got ", got); 99 printf (" got exp %ld\n", got_exp); 100 abort(); 101 } 102 } 103 } 104 105 mpf_clear (f); 106 tests_hardware_setround (old_rnd_mode); 107 } 108 109 110 int 111 main (void) 112 { 113 tests_start (); 114 mp_trace_base = 16; 115 116 check_onebit (); 117 check_round (); 118 119 tests_end (); 120 exit (0); 121 } 122