github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/tests/mpz/t-invert.c (about)

     1  /* Test mpz_invert.
     2  
     3  Copyright 1991, 1993, 1994, 1996, 1997, 2000-2005, 2008, 2009, 2012, 2014 Free
     4  Software Foundation, Inc.
     5  
     6  This file is part of the GNU MP Library test suite.
     7  
     8  The GNU MP Library test suite is free software; you can redistribute it
     9  and/or modify it under the terms of the GNU General Public License as
    10  published by the Free Software Foundation; either version 3 of the License,
    11  or (at your option) any later version.
    12  
    13  The GNU MP Library test suite is distributed in the hope that it will be
    14  useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
    15  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
    16  Public License for more details.
    17  
    18  You should have received a copy of the GNU General Public License along with
    19  the GNU MP Library test suite.  If not, see https://www.gnu.org/licenses/.  */
    20  
    21  #include <stdio.h>
    22  #include <stdlib.h>
    23  
    24  #include "gmp.h"
    25  #include "gmp-impl.h"
    26  #include "tests.h"
    27  
    28  int
    29  main (int argc, char **argv)
    30  {
    31    mpz_t a, m, ainv, t;
    32    int test, r;
    33    gmp_randstate_ptr rands;
    34    mpz_t bs;
    35    unsigned long bsi, size_range;
    36    int reps = 1000;
    37  
    38    tests_start ();
    39    TESTS_REPS (reps, argv, argc);
    40  
    41    rands = RANDS;
    42  
    43    mpz_init (bs);
    44    mpz_init (a);
    45    mpz_init (m);
    46    mpz_init (ainv);
    47    mpz_init (t);
    48  
    49    for (test = 0; test < reps; test++)
    50      {
    51        mpz_urandomb (bs, rands, 32);
    52        size_range = mpz_get_ui (bs) % 16 + 2;
    53  
    54        mpz_urandomb (bs, rands, size_range);
    55        mpz_rrandomb (a, rands, mpz_get_ui (bs));
    56        do {
    57  	mpz_urandomb (bs, rands, size_range);
    58  	mpz_rrandomb (m, rands, mpz_get_ui (bs));
    59        } while (mpz_sgn (m) == 0);
    60  
    61        mpz_urandomb (bs, rands, 8);
    62        bsi = mpz_get_ui (bs);
    63  
    64        if ((bsi & 1) != 0)
    65  	mpz_neg (a, a);
    66        if ((bsi & 2) != 0)
    67  	mpz_neg (m, m);
    68  
    69        r = mpz_invert (ainv, a, m);
    70        if (r != 0)
    71  	{
    72  	  MPZ_CHECK_FORMAT (ainv);
    73  
    74  	  if (mpz_cmp_ui (ainv, 0) < 0 || mpz_cmpabs (ainv, m) >= 0)
    75  	    {
    76  	      fprintf (stderr, "ERROR in test %d\n", test);
    77  	      gmp_fprintf (stderr, "Inverse out of range.\n");
    78  	      gmp_fprintf (stderr, "a = %Zx\n", a);
    79  	      gmp_fprintf (stderr, "1/a = %Zx\n", ainv);
    80  	      gmp_fprintf (stderr, "m = %Zx\n", m);
    81  	      abort ();
    82  	    }
    83  
    84  	  mpz_mul (t, ainv, a);
    85  	  mpz_mod (t, t, m);
    86  
    87  	  if (mpz_cmp_ui (t, mpz_cmpabs_ui (m, 1) != 0) != 0)
    88  	    {
    89  	      fprintf (stderr, "ERROR in test %d\n", test);
    90  	      gmp_fprintf (stderr, "a^(-1)*a != 1 (mod m)\n");
    91  	      gmp_fprintf (stderr, "a = %Zx\n", a);
    92  	      gmp_fprintf (stderr, "m = %Zx\n", m);
    93  	      abort ();
    94  	    }
    95  	}
    96        else /* Inverse deos not exist */
    97  	{
    98  	  if (mpz_cmpabs_ui (m, 1) <= 0)
    99  	    continue; /* OK */
   100  
   101  	  mpz_gcd (t, a, m);
   102  	  if (mpz_cmp_ui (t, 1) == 0)
   103  	    {
   104  	      fprintf (stderr, "ERROR in test %d\n", test);
   105  	      gmp_fprintf (stderr, "Inverse exists, but was not found.\n");
   106  	      gmp_fprintf (stderr, "a = %Zx\n", a);
   107  	      gmp_fprintf (stderr, "m = %Zx\n", m);
   108  	      abort ();
   109  	    }
   110  	}
   111      }
   112  
   113    mpz_clear (bs);
   114    mpz_clear (a);
   115    mpz_clear (m);
   116    mpz_clear (ainv);
   117    mpz_clear (t);
   118  
   119    tests_end ();
   120    exit (0);
   121  }