src/mpfr-3.1.4/tests/tget_flt.c

/* Test file for mpfr_get_flt and mpfr_set_flt

Copyright 2009-2016 Free Software Foundation, Inc.
Contributed by the AriC and Caramba projects, INRIA.

This file is part of the GNU MPFR Library.

The GNU 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 3 of the License, or (at your
option) any later version.

The GNU 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 GNU MPFR Library; see the file COPYING.LESSER.  If not, see
http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */

#include <stdlib.h>
#include <float.h>     /* for FLT_MIN */
#include "mpfr-test.h"

int
main (void)
{
  mpfr_t x, y;
  float f, g;
  int i;
#if !defined(MPFR_ERRDIVZERO)
  float infp;
#endif

  tests_start_mpfr ();

#if !defined(MPFR_ERRDIVZERO)
  /* The definition of DBL_POS_INF involves a division by 0. This makes
     "clang -O2 -fsanitize=undefined -fno-sanitize-recover" fail. */
  infp = (float) DBL_POS_INF;
  if (infp * 0.5 != infp)
    {
      fprintf (stderr, "Error, FLT_MAX + FLT_MAX does not yield INFP\n");
      fprintf (stderr, "(this is probably a compiler bug, please report)\n");
      exit (1);
    }
#endif

  mpfr_init2 (x, 24);
  mpfr_init2 (y, 24);

#if !defined(MPFR_ERRDIVZERO)
  mpfr_set_nan (x);
  f = mpfr_get_flt (x, MPFR_RNDN);
  if (! DOUBLE_ISNAN (f))
    {
      printf ("Error for mpfr_get_flt(NaN)\n");
      printf ("got f=%f\n", f);
      exit (1);
    }
  mpfr_set_flt (x, f, MPFR_RNDN);
  if (mpfr_nan_p (x) == 0)
    {
      printf ("Error for mpfr_set_flt(NaN)\n");
      exit (1);
    }

  mpfr_set_inf (x, 1);
  f = mpfr_get_flt (x, MPFR_RNDN);
  mpfr_set_flt (x, f, MPFR_RNDN);
  if (mpfr_inf_p (x) == 0 || mpfr_sgn (x) < 0)
    {
      printf ("Error for mpfr_set_flt(mpfr_get_flt(+Inf)):\n");
      printf ("f=%f, expected -Inf\n", f);
      printf ("got "); mpfr_dump (x);
      exit (1);
    }

  mpfr_set_inf (x, -1);
  f = mpfr_get_flt (x, MPFR_RNDN);
  mpfr_set_flt (x, f, MPFR_RNDN);
  if (mpfr_inf_p (x) == 0 || mpfr_sgn (x) > 0)
    {
      printf ("Error for mpfr_set_flt(mpfr_get_flt(-Inf)):\n");
      printf ("f=%f, expected -Inf\n", f);
      printf ("got "); mpfr_dump (x);
      exit (1);
    }
#endif

  mpfr_set_ui (x, 0, MPFR_RNDN);
  f = mpfr_get_flt (x, MPFR_RNDN);
  mpfr_set_flt (x, f, MPFR_RNDN);
  if (mpfr_zero_p (x) == 0 || MPFR_SIGN (x) < 0)
    {
      printf ("Error for mpfr_set_flt(mpfr_get_flt(+0))\n");
      exit (1);
    }

#ifdef HAVE_SIGNEDZ
  mpfr_set_ui (x, 0, MPFR_RNDN);
  mpfr_neg (x, x, MPFR_RNDN);
  f = mpfr_get_flt (x, MPFR_RNDN);
  mpfr_set_flt (x, f, MPFR_RNDN);
  if (mpfr_zero_p (x) == 0 || MPFR_SIGN (x) > 0)
    {
      printf ("Error for mpfr_set_flt(mpfr_get_flt(-0))\n");
      exit (1);
    }
#endif  /* HAVE_SIGNEDZ */

  mpfr_set_ui (x, 17, MPFR_RNDN);
  f = mpfr_get_flt (x, MPFR_RNDN);
  mpfr_set_flt (x, f, MPFR_RNDN);
  if (mpfr_cmp_ui (x, 17) != 0)
    {
      printf ("Error for mpfr_set_flt(mpfr_get_flt(17))\n");
      printf ("expected 17\n");
      printf ("got      ");
      mpfr_dump (x);
      exit (1);
    }

  mpfr_set_si (x, -42, MPFR_RNDN);
  f = mpfr_get_flt (x, MPFR_RNDN);
  mpfr_set_flt (x, f, MPFR_RNDN);
  if (mpfr_cmp_si (x, -42) != 0)
    {
      printf ("Error for mpfr_set_flt(mpfr_get_flt(-42))\n");
      printf ("expected -42\n");
      printf ("got      ");
      mpfr_dump (x);
      exit (1);
    }

  mpfr_set_si_2exp (x, 1, -126, MPFR_RNDN);
  for (i = -126; i < 128; i++)
    {
      f = mpfr_get_flt (x, MPFR_RNDN);
      mpfr_set_flt (y, f, MPFR_RNDN);
      if (mpfr_cmp (x, y) != 0)
        {
          printf ("Error for mpfr_set_flt(mpfr_get_flt(x))\n");
          printf ("expected "); mpfr_dump (x);
          printf ("got      "); mpfr_dump (y);
          exit (1);
        }
      mpfr_mul_2exp (x, x, 1, MPFR_RNDN);
    }

  mpfr_set_prec (x, 53);
  mpfr_set_si_2exp (x, 1, -126, MPFR_RNDN);
  for (i = -126; i < 128; i++)
    {
      mpfr_nextbelow (x);
      f = mpfr_get_flt (x, MPFR_RNDN);
      mpfr_nextabove (x);
      mpfr_set_flt (y, f, MPFR_RNDN);
      if (mpfr_cmp (x, y) != 0)
        {
          printf ("Error for mpfr_set_flt(mpfr_get_flt(x))\n");
          printf ("expected "); mpfr_dump (x);
          printf ("got      "); mpfr_dump (y);
          exit (1);
        }
      mpfr_mul_2exp (x, x, 1, MPFR_RNDN);
    }

  mpfr_set_prec (x, 53);
  mpfr_set_si_2exp (x, 1, -126, MPFR_RNDN);
  for (i = -126; i < 128; i++)
    {
      mpfr_nextabove (x);
      f = mpfr_get_flt (x, MPFR_RNDN);
      mpfr_nextbelow (x);
      mpfr_set_flt (y, f, MPFR_RNDN);
      if (mpfr_cmp (x, y) != 0)
        {
          printf ("Error for mpfr_set_flt(mpfr_get_flt(x))\n");
          printf ("expected "); mpfr_dump (x);
          printf ("got      "); mpfr_dump (y);
          exit (1);
        }
      mpfr_mul_2exp (x, x, 1, MPFR_RNDN);
    }

#ifdef HAVE_DENORMS
  mpfr_set_si_2exp (x, 1, -150, MPFR_RNDN);
  g = 0.0;
  f = mpfr_get_flt (x, MPFR_RNDN);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-150),RNDN)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDZ);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-150),RNDZ)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDD);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-150),RNDD)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  g = FLT_MIN * FLT_EPSILON;
  f = mpfr_get_flt (x, MPFR_RNDU);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-150),RNDU)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDA);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-150),RNDA)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }

  mpfr_set_si_2exp (x, 1, -151, MPFR_RNDN);
  g = 0.0;
  f = mpfr_get_flt (x, MPFR_RNDN);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-151),RNDN)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDZ);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-151),RNDZ)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDD);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-151),RNDD)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  g = FLT_MIN * FLT_EPSILON;
  f = mpfr_get_flt (x, MPFR_RNDU);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-151),RNDU)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDA);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-151),RNDA)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }

  mpfr_set_si_2exp (x, 1, -149, MPFR_RNDN);
  g = FLT_MIN * FLT_EPSILON;
  f = mpfr_get_flt (x, MPFR_RNDN);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-149),RNDN)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDZ);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-149),RNDZ)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDD);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-149),RNDD)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDU);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-149),RNDU)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDA);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^(-149),RNDA)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
#endif

  mpfr_set_si_2exp (x, 1, 128, MPFR_RNDN);
  g = FLT_MAX;
  f = mpfr_get_flt (x, MPFR_RNDZ);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128,RNDZ)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDD);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128,RNDD)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
#if !defined(MPFR_ERRDIVZERO)
  f = mpfr_get_flt (x, MPFR_RNDN); /* 2^128 rounds to itself with extended
                                      exponent range, we should get +Inf */
  g = infp;
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128,RNDN)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDU);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128,RNDU)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDA);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128,RNDA)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
#endif

  /* corner case: take x with 25 bits just below 2^128 */
  mpfr_set_prec (x, 25);
  mpfr_set_si_2exp (x, 1, 128, MPFR_RNDN);
  mpfr_nextbelow (x);
  g = FLT_MAX;
  f = mpfr_get_flt (x, MPFR_RNDZ);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128*(1-2^(-25)),RNDZ)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDD);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128*(1-2^(-25)),RNDD)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
#if !defined(MPFR_ERRDIVZERO)
  f = mpfr_get_flt (x, MPFR_RNDN); /* first round to 2^128 (even rule),
                                      thus we should get +Inf */
  g = infp;
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128*(1-2^(-25)),RNDN)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDU);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128*(1-2^(-25)),RNDU)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
  f = mpfr_get_flt (x, MPFR_RNDA);
  if (f != g)
    {
      printf ("Error for mpfr_get_flt(2^128*(1-2^(-25)),RNDA)\n");
      printf ("expected %.8e, got %.8e\n", g, f);
      exit (1);
    }
#endif

  mpfr_clear (x);
  mpfr_clear (y);

  tests_end_mpfr ();
  return 0;
}