tset_d.c

a very popular packet of cryptography tools,it encloses the most common used algorithm and protocols

/* Test file for mpfr_set_d and mpfr_get_d.

Copyright 1999, 2000, 2001, 2002 Free Software Foundation, Inc.

This file is part of the MPFR Library.

The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.

The MPFR Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the MPFR Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */

#include <float.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "gmp.h"
#include "mpfr.h"
#include "mpfr-test.h"

int
main (int argc, char *argv[])
{
  mpfr_t x, y, z;
  unsigned long k, n;
  double d, dd;
  
  mpfr_test_init ();

  mpfr_init2 (x, 2);

  /* checks that denormalized are not flushed to zero */
  d = DBL_MIN; /* 2^(-1022) */
  for (n=0; n<52; n++, d /= 2.0)
    if (d != 0.0) /* should be 2^(-1022-n) */
      {
        mpfr_set_d (x, d, GMP_RNDN);
        if (mpfr_cmp_ui_2exp (x, 1, -1022-n))
          {
            fprintf (stderr, "Wrong result for d=2^(%ld), ", -1022-n);
            fprintf (stderr, "got ");
            mpfr_out_str (stderr, 10, 10, x, GMP_RNDN);
            fprintf (stderr, "\n");
            mpfr_print_binary (x); putchar ('\n');
            exit (1);
          }
      }

   /* checks that rounds to nearest sets the last
     bit to zero in case of equal distance */
   mpfr_set_d (x, 5.0, GMP_RNDN);
   if (mpfr_get_d1 (x) != 4.0)
     {
       fprintf (stderr, "Error in tset_d: got %g instead of 4.0\n",
	       mpfr_get_d1 (x));
       exit (1);
     }
   mpfr_set_d (x, -5.0, GMP_RNDN);
   if (mpfr_get_d1 (x) != -4.0)
     {
       fprintf (stderr, "Error in tset_d: got %g instead of -4.0\n",
	       mpfr_get_d1 (x));
       exit (1);
     }

   mpfr_set_d (x, 9.84891017624509146344e-01, GMP_RNDU); 
   if (mpfr_get_d1 (x) != 1.0)
     {
       fprintf (stderr, "Error in tset_d: got %g instead of 1.0\n",
		mpfr_get_d1 (x));
       exit (1);
     }

  mpfr_init2(z, 32);
  mpfr_set_d(z, 1.0, 0);
  if (mpfr_get_d1 (z) != 1.0) {
    mpfr_print_binary(z); putchar('\n');
    printf("Error: 1.0 != 1.0\n"); exit(1);
  }
  mpfr_set_prec(x, 53); mpfr_init2(y, 53);
  mpfr_set_d(x, d=-1.08007920352320089721e+150, 0);
  if (mpfr_get_d1 (x) != d) {
    mpfr_print_binary(x); putchar('\n');
    printf("Error: get_d o set_d <> identity for d = %1.20e %1.20e\n",d,
	   mpfr_get_d1 (x)); exit(1);
  }

  SEED_RAND (time(NULL));
  mpfr_set_d(x, 8.06294740693074521573e-310, 0); 
  d = -6.72658901114033715233e-165;
  mpfr_set_d(x, d, 0);
  if (d != mpfr_get_d1 (x)) {
    mpfr_print_binary(x); putchar('\n');
    printf("Error: get_d o set_d <> identity for d = %1.20e %1.20e\n",d,
	   mpfr_get_d1 (x)); exit(1);
  }
  n = (argc==1) ? 1000000 : atoi(argv[1]);
  for (k = 1; k <= n; k++)
    {      
      do
	{
	  d = drand();
	}
#ifdef HAVE_DENORMS
      while (0);
#else
      while (ABS(d) <= 2.2e-307);
#endif
      mpfr_set_d (x, d, 0);
      dd = mpfr_get_d1 (x);
      if (d != dd && (!isnan(d) || !isnan(dd)))
	{ 
	  fprintf(stderr, 
		  "Mismatch on : %1.18g != %1.18g\n", d, mpfr_get_d1 (x)); 
	  mpfr_print_binary(x); putchar('\n');
	  exit(1);
	}
    }

  mpfr_clear(x); mpfr_clear(y); mpfr_clear(z);

  return 0; 
}