/* Test mpf_sqrt_ui.

Copyright 2004, 2015 Free Software Foundation, Inc.

This file is part of the GNU MP Library test suite.

The GNU MP Library test suite is free software; you can redistribute it

and/or modify it under the terms of the GNU 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 MP Library test suite 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 General

Public License for more details.

You should have received a copy of the GNU General Public License along with

the GNU MP Library test suite.  If not, see https://www.gnu.org/licenses/.  */

#include <stdio.h>

#include <stdlib.h>

#include "gmp.h"

#include "gmp-impl.h"

#include "tests.h"

void

check_rand (void)

{

  unsigned long      max_prec = 15;

  unsigned long      min_prec = __GMPF_BITS_TO_PREC (1);

  gmp_randstate_ptr  rands = RANDS;

  unsigned long      x, prec;

  mpf_t              r, s;

  int                i;

  mpf_init (r);

  mpf_init (s);

  refmpf_set_prec_limbs (s, 2*max_prec+10);

  for (x = 0; x < 2; x++)

    {

      mpf_sqrt_ui (r, x);

      MPF_CHECK_FORMAT (r);

      if (mpf_cmp_ui (r, x) != 0)

	{

	  printf    ("mpf_sqrt_ui wrong for special case:\n");

          printf    ("  x=%lu\n", x);

          mpf_trace ("  r", r);

	  abort ();

	}

    }

  for (i = 0; i < 50; i++)

    {

      /* input, a random non-zero ulong, exponentially distributed */

      do {

        x = gmp_urandomb_ui (rands,

                             gmp_urandomm_ui (rands, BITS_PER_ULONG) + 1);

      } while (x <= 1);

      /* result precision */

      prec = gmp_urandomm_ui (rands, max_prec-min_prec) + min_prec;

      refmpf_set_prec_limbs (r, prec);

      mpf_sqrt_ui (r, x);

      MPF_CHECK_FORMAT (r);

      /* Expect to prec limbs of result.

         In the current implementation there's no stripping of low zero

         limbs in mpf_sqrt_ui, not even on perfect squares, so size should

         be exactly prec.  */

      if (SIZ(r) != prec)

        {

          printf ("mpf_sqrt_ui result not enough result limbs\n");

          printf    ("  x=%lu\n", x);

          printf    ("  want prec=%lu\n", prec);

          mpf_trace ("  r", r);

          printf    ("  r size %ld\n", (long) SIZ(r));

          printf    ("  r prec %ld\n", (long) PREC(r));

          abort ();

        }

      /* Must have r^2 <= x, since r has been truncated. */

      mpf_mul (s, r, r);

      if (! (mpf_cmp_ui (s, x) <= 0))

        {

          printf    ("mpf_sqrt_ui result too big\n");

          printf    ("  x=%lu\n", x);

          printf    ("  want prec=%lu\n", prec);

          mpf_trace ("  r", r);

          mpf_trace ("  s", s);

          abort ();

        }

      /* Must have (r+ulp)^2 > x.

         No overflow from refmpf_add_ulp since r is only prec limbs. */

      refmpf_add_ulp (r);

      mpf_mul (s, r, r);

      if (! (mpf_cmp_ui (s, x) > 0))

        {

          printf    ("mpf_sqrt_ui result too small\n");

          printf    ("  x=%lu\n", x);

          printf    ("  want prec=%lu\n", prec);

          mpf_trace ("  r+ulp", r);

          mpf_trace ("  s", s);

          abort ();

        }

    }

  mpf_clear (r);

  mpf_clear (s);

}

int

main (int argc, char **argv)

{

  tests_start ();

  mp_trace_base = -16;

  check_rand ();

  tests_end ();

  exit (0);

}