1/* Test mpfr_get_ld_2exp. 2 3Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc. 4Contributed by the AriC and Caramel projects, INRIA. 5 6This file is part of the GNU MPFR Library. 7 8The GNU MPFR Library is free software; you can redistribute it and/or modify 9it under the terms of the GNU Lesser General Public License as published by 10the Free Software Foundation; either version 3 of the License, or (at your 11option) any later version. 12 13The GNU MPFR Library is distributed in the hope that it will be useful, but 14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 15or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 16License for more details. 17 18You should have received a copy of the GNU Lesser General Public License 19along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see 20http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., 2151 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/* Check that hardware rounding doesn't make mpfr_get_ld_2exp return a value 30 outside its defined range. */ 31static void 32check_round (void) 33{ 34 static const unsigned long data[] = {1, 32, 53, 54, 63, 64, 65, 127, 128, 256, 512 }; 35 mpfr_t f; 36 long double got; 37 long got_exp; 38 int i, rnd_mode, neg; 39 40 mpfr_init2 (f, 1024L); 41 42 for (rnd_mode = 0; rnd_mode < MPFR_RND_MAX ; rnd_mode++) 43 { 44 for (i = 0; i < (int) numberof (data); i++) 45 { 46 mpfr_set_ui (f, 1L, MPFR_RNDZ); 47 mpfr_mul_2exp (f, f, data[i], MPFR_RNDZ); 48 mpfr_sub_ui (f, f, 1L, MPFR_RNDZ); 49 50 for (neg = 0; neg <= 1; neg++) 51 { 52 got = mpfr_get_ld_2exp (&got_exp, f, (mpfr_rnd_t) rnd_mode); 53 54 if (neg == 0 55 ? (got < 0.5 || got >= 1.0) 56 : (got <= -1.0 || got > -0.5)) 57 { 58 printf ("mpfr_get_ld_2exp wrong on 2**%lu-1\n", data[i]); 59 printf ("result out of range, expect 0.5 <= got < 1.0\n"); 60 printf (" rnd_mode = %d\n", rnd_mode); 61 printf (" data[i] = %lu\n", data[i]); 62 printf (" f "); 63 mpfr_out_str (stdout, 2, 0, f, MPFR_RNDN); 64 printf ("\n"); 65 d_trace (" got ", got); 66 printf (" got exp %ld\n", got_exp); 67 exit(1); 68 } 69 70 mpfr_neg (f, f, MPFR_RNDZ); 71 } 72 } 73 } 74 75 mpfr_clear (f); 76} 77 78 79static void 80check_inf_nan (void) 81{ 82 /* only if nans and infs are available */ 83#if _GMP_IEEE_FLOATS 84 mpfr_t x; 85 double d; 86 long exp; 87 88 mpfr_init2 (x, 123); 89 90 mpfr_set_inf (x, 1); 91 d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ); 92 ASSERT_ALWAYS (d > 0); 93 ASSERT_ALWAYS (DOUBLE_ISINF (d)); 94 95 mpfr_set_inf (x, -1); 96 d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ); 97 ASSERT_ALWAYS (d < 0); 98 ASSERT_ALWAYS (DOUBLE_ISINF (d)); 99 100 mpfr_set_nan (x); 101 d = (double) mpfr_get_ld_2exp (&exp, x, MPFR_RNDZ); 102 ASSERT_ALWAYS (DOUBLE_ISNAN (d)); 103 104 mpfr_clear (x); 105#endif 106} 107 108static void 109bug20090520 (void) 110{ 111 mpfr_t x; 112 long double d, e; 113 int i; 114 115 mpfr_init (x); 116 mpfr_set_ui (x, 1, MPFR_RNDN); 117 d = 1.0; 118 mpfr_div_2exp (x, x, 16383, MPFR_RNDN); 119 for (i = 0; i < 16383; i++) 120 d *= 0.5; 121 e = mpfr_get_ld (x, MPFR_RNDN); 122 if (e != d) 123 { 124 printf ("mpfr_get_ld(1e-16383) failed\n"); 125 printf ("expected %.20Le\n", d); 126 printf ("got %.20Le\n", e); 127 exit (1); 128 } 129 mpfr_clear (x); 130} 131 132int 133main (void) 134{ 135 tests_start_mpfr (); 136 mpfr_test_init (); 137 138 bug20090520 (); 139 140 check_round (); 141 check_inf_nan (); 142 143 tests_end_mpfr (); 144 return 0; 145} 146