gcc/mpfr/tests/trec_sqrt.c

/* Test file for mpfr_rec_sqrt.

Copyright 2008, 2009 Free Software Foundation, Inc.
Contributed by the Arenaire and Cacao 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 2.1 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.LIB.  If not, write to
the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
MA 02110-1301, USA. */

#include <stdio.h>
#include <stdlib.h>

#include "mpfr-test.h"

#if MPFR_VERSION >= MPFR_VERSION_NUM(2,4,0)

#define TEST_FUNCTION mpfr_rec_sqrt
#define TEST_RANDOM_POS 8 /* 8/512 = 1/64 of the tested numbers are negative */
#include "tgeneric.c"

static void
special (void)
{
  mpfr_t x, y;
  int inex;

  mpfr_init (x);
  mpfr_init (y);

  /* rec_sqrt(NaN) = NaN */
  mpfr_set_nan (x);
  inex = mpfr_rec_sqrt (x, x, GMP_RNDN);
  MPFR_ASSERTN(mpfr_nan_p (x) && inex == 0);

  /* rec_sqrt(+Inf) = +0 */
  mpfr_set_inf (x, 1);
  inex = mpfr_rec_sqrt (x, x, GMP_RNDN);
  MPFR_ASSERTN(mpfr_zero_p (x) && MPFR_IS_POS(x) && inex == 0);

  /* rec_sqrt(-Inf) = NaN */
  mpfr_set_inf (x, -1);
  inex = mpfr_rec_sqrt (x, x, GMP_RNDN);
  MPFR_ASSERTN(mpfr_nan_p (x) && inex == 0);

  /* rec_sqrt(+0) = +Inf */
  mpfr_set_ui (x, 0, GMP_RNDN);
  inex = mpfr_rec_sqrt (x, x, GMP_RNDN);
  MPFR_ASSERTN(mpfr_inf_p (x) && MPFR_IS_POS(x) && inex == 0);

  /* rec_sqrt(-0) = +Inf */
  mpfr_set_ui (x, 0, GMP_RNDN);
  mpfr_neg (x, x, GMP_RNDN);
  inex = mpfr_rec_sqrt (x, x, GMP_RNDN);
  MPFR_ASSERTN(mpfr_inf_p (x) && MPFR_IS_POS(x) && inex == 0);

  /* rec_sqrt(-1) = NaN */
  mpfr_set_si (x, -1, GMP_RNDN);
  inex = mpfr_rec_sqrt (x, x, GMP_RNDN);
  MPFR_ASSERTN(mpfr_nan_p (x) && inex == 0);

  /* rec_sqrt(1) = 1 */
  mpfr_set_ui (x, 1, GMP_RNDN);
  inex = mpfr_rec_sqrt (x, x, GMP_RNDN);
  MPFR_ASSERTN((mpfr_cmp_ui (x, 1) == 0) && (inex == 0));

  mpfr_set_prec (x, 23);
  mpfr_set_prec (y, 33);
  mpfr_set_str_binary (x, "1.0001110110101001010100e-1");
  inex = mpfr_rec_sqrt (y, x, GMP_RNDU);
  mpfr_set_prec (x, 33);
  mpfr_set_str_binary (x, "1.01010110101110100100100101011");
  MPFR_ASSERTN (inex > 0 && mpfr_cmp (x, y) == 0);

  mpfr_clear (x);
  mpfr_clear (y);
}

/* Worst case incorrectly rounded in r5573, found with the bad_cases test */
static void
bad_case1 (void)
{
  mpfr_t x, y, z;

  mpfr_init2 (x, 72);
  mpfr_inits2 (6, y, z, (mpfr_ptr) 0);
  mpfr_set_str (x, "1.08310518720928b30e@-120", 16, GMP_RNDN);
  mpfr_set_str (z, "f.8@59", 16, GMP_RNDN);
  /* z = rec_sqrt(x) rounded on 6 bits toward 0, the exact value
     being ~= f.bffffffffffffffffa11@59. */
  mpfr_rec_sqrt (y, x, GMP_RNDZ);
  if (mpfr_cmp0 (y, z) != 0)
    {
      printf ("Error in bad_case1\nexpected ");
      mpfr_out_str (stdout, 16, 0, z, GMP_RNDN);
      printf ("\ngot      ");
      mpfr_out_str (stdout, 16, 0, y, GMP_RNDN);
      printf ("\n");
      exit (1);
    }
  mpfr_clears (x, y, z, (mpfr_ptr) 0);
}

static int
pm2 (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t rnd_mode)
{
  return mpfr_pow_si (y, x, -2, rnd_mode);
}

int
main (void)
{
  tests_start_mpfr ();

  special ();
  bad_case1 ();
  test_generic (2, 300, 15);

  data_check ("data/rec_sqrt", mpfr_rec_sqrt, "mpfr_rec_sqrt");
  bad_cases (mpfr_rec_sqrt, pm2, "mpfr_rec_sqrt", 8, -256, 255, 4, 128,
             800, 50);

  tests_end_mpfr ();
  return 0;
}

#else  /* MPFR_VERSION */

int
main (void)
{
  printf ("Warning! Test disabled for this MPFR version.\n");
  return 0;
}

#endif  /* MPFR_VERSION */