1  /*
       2  
       3  Copyright 2012, 2013 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 https://www.gnu.org/licenses/.  */
      19  
      20  #include <limits.h>
      21  #include <stdlib.h>
      22  #include <stdio.h>
      23  
      24  #include "testutils.h"
      25  
      26  #define MAXBITS 400
      27  #define COUNT 10000
      28  
      29  /* Called when s is supposed to be floor(root(u,z)), and r = u - s^z */
      30  static int
      31  rootrem_valid_p (const mpz_t u, const mpz_t s, const mpz_t r, unsigned long z)
      32  {
      33    mpz_t t;
      34  
      35    mpz_init (t);
      36    if (mpz_fits_ulong_p (s))
      37      mpz_ui_pow_ui (t, mpz_get_ui (s), z);
      38    else
      39      mpz_pow_ui (t, s, z);
      40    mpz_sub (t, u, t);
      41    if ((mpz_sgn (t) != mpz_sgn(u) && mpz_sgn (t) != 0) || mpz_cmp (t, r) != 0)
      42      {
      43        mpz_clear (t);
      44        return 0;
      45      }
      46    if (mpz_sgn (s) > 0)
      47      mpz_add_ui (t, s, 1);
      48    else
      49      mpz_sub_ui (t, s, 1);
      50    mpz_pow_ui (t, t, z);
      51    if (mpz_cmpabs (t, u) <= 0)
      52      {
      53        mpz_clear (t);
      54        return 0;
      55      }
      56  
      57    mpz_clear (t);
      58    return 1;
      59  }
      60  
      61  void
      62  testmain (int argc, char **argv)
      63  {
      64    unsigned i;
      65    unsigned long e;
      66    mpz_t u, s, r, bs;
      67  
      68    mpz_init (u);
      69    mpz_init (s);
      70    mpz_init (r);
      71    mpz_init (bs);
      72  
      73    for (i = 0; i < COUNT; i++)
      74      {
      75        mini_rrandomb (u, MAXBITS);
      76        mini_rrandomb (bs, 12);
      77        e = mpz_getlimbn (bs, 0) % mpz_sizeinbase (u, 2) + 1;
      78        if ((e & 1) && (mpz_getlimbn (bs, 0) & (1L<<10)))
      79  	mpz_neg (u, u);
      80        mpz_rootrem (s, r, u, e);
      81  
      82        if (!rootrem_valid_p (u, s, r, e))
      83  	{
      84  	  fprintf (stderr, "mpz_rootrem(%lu-th) failed:\n", e);
      85  	  dump ("u", u);
      86  	  dump ("root", s);
      87  	  dump ("rem", r);
      88  	  abort ();
      89  	}
      90      }
      91    mpz_clear (bs);
      92    mpz_clear (u);
      93    mpz_clear (s);
      94    mpz_clear (r);
      95  }