1/* Test file for mpfr_sub_ui 2 3Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. 4Contributed by the Arenaire and Cacao 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/* checks that x-y gives the right results with 53 bits of precision */ 30static void 31check3 (const char *xs, unsigned long y, mpfr_rnd_t rnd_mode, const char *zs) 32{ 33 mpfr_t xx,zz; 34 35 mpfr_inits2 (53, xx, zz, (mpfr_ptr) 0); 36 mpfr_set_str1 (xx, xs); 37 mpfr_sub_ui (zz, xx, y, rnd_mode); 38 if (mpfr_cmp_str1(zz, zs)) 39 { 40 printf ("expected sum is %s, got ", zs); 41 mpfr_print_binary(zz); 42 printf ("\nmpfr_sub_ui failed for x=%s y=%lu with rnd_mode=%s\n", 43 xs, y, mpfr_print_rnd_mode (rnd_mode)); 44 exit (1); 45 } 46 mpfr_clears (xx, zz, (mpfr_ptr) 0); 47} 48 49/* FastTwoSum: if EXP(x) >= EXP(y), u = o(x+y), v = o(u-x), w = o(y-v), 50 then x + y = u + w 51thus if u = o(y-x), v = o(u+x), w = o(v-y), then y-x = u-w */ 52static void 53check_two_sum (mpfr_prec_t p) 54{ 55 unsigned int x; 56 mpfr_t y, u, v, w; 57 mpfr_rnd_t rnd; 58 int inexact; 59 60 mpfr_inits2 (p, y, u, v, w, (mpfr_ptr) 0); 61 do 62 { 63 x = randlimb (); 64 } 65 while (x < 1); 66 mpfr_urandomb (y, RANDS); 67 rnd = MPFR_RNDN; 68 inexact = mpfr_sub_ui (u, y, x, rnd); 69 mpfr_add_ui (v, u, x, rnd); 70 mpfr_sub (w, v, y, rnd); 71 /* as u - (y-x) = w, we should have inexact and w of same sign */ 72 if (((inexact == 0) && mpfr_cmp_ui (w, 0)) || 73 ((inexact > 0) && (mpfr_cmp_ui (w, 0) <= 0)) || 74 ((inexact < 0) && (mpfr_cmp_ui (w, 0) >= 0))) 75 { 76 printf ("Wrong inexact flag for prec=%u, rnd=%s\n", 77 (unsigned int) p, mpfr_print_rnd_mode (rnd)); 78 printf ("x=%u\n", x); 79 printf ("y="); mpfr_print_binary(y); puts (""); 80 printf ("u="); mpfr_print_binary(u); puts (""); 81 printf ("v="); mpfr_print_binary(v); puts (""); 82 printf ("w="); mpfr_print_binary(w); puts (""); 83 printf ("inexact = %d\n", inexact); 84 exit (1); 85 } 86 mpfr_clears (y, u, v, w, (mpfr_ptr) 0); 87} 88 89static void 90check_nans (void) 91{ 92 mpfr_t x, y; 93 94 mpfr_init2 (x, 123L); 95 mpfr_init2 (y, 123L); 96 97 /* nan - 1 == nan */ 98 mpfr_set_nan (x); 99 mpfr_sub_ui (y, x, 1L, MPFR_RNDN); 100 MPFR_ASSERTN (mpfr_nan_p (y)); 101 102 /* +inf - 1 == +inf */ 103 mpfr_set_inf (x, 1); 104 mpfr_sub_ui (y, x, 1L, MPFR_RNDN); 105 MPFR_ASSERTN (mpfr_inf_p (y)); 106 MPFR_ASSERTN (mpfr_sgn (y) > 0); 107 108 /* -inf - 1 == -inf */ 109 mpfr_set_inf (x, -1); 110 mpfr_sub_ui (y, x, 1L, MPFR_RNDN); 111 MPFR_ASSERTN (mpfr_inf_p (y)); 112 MPFR_ASSERTN (mpfr_sgn (y) < 0); 113 114 mpfr_clear (x); 115 mpfr_clear (y); 116} 117 118#define TEST_FUNCTION mpfr_sub_ui 119#define INTEGER_TYPE unsigned long 120#define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS) 121#include "tgeneric_ui.c" 122 123int 124main (int argc, char *argv[]) 125{ 126 mpfr_prec_t p; 127 int k; 128 129 tests_start_mpfr (); 130 131 check_nans (); 132 133 for (p=2; p<200; p++) 134 for (k=0; k<200; k++) 135 check_two_sum (p); 136 137 check3 ("0.9999999999", 1, MPFR_RNDN, 138 "-10000000827403709990903735160827636718750e-50"); 139 140 test_generic_ui (2, 1000, 100); 141 142 tests_end_mpfr (); 143 return 0; 144} 145