path: root/tests/tmul_ui.c

/* Test file for mpfr_mul_ui.

Copyright 1999-2020 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
https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */

#include "mpfr-test.h"

static void
check_inexact (mpfr_prec_t p)
{
  mpfr_t x, y, z;
  unsigned long u;
  mpfr_prec_t q;
  int inexact, cmp;
  int rnd;

  mpfr_init2 (x, p);
  mpfr_init (y);
  mpfr_init2 (z, p + mp_bits_per_limb);
  mpfr_urandomb (x, RANDS);
  u = randlimb ();
  if (mpfr_mul_ui (z, x, u, MPFR_RNDN))
    {
      printf ("Error: result should be exact\n");
      exit (1);
    }

  for (q = MPFR_PREC_MIN; q <= p; q++)
    for (rnd = 0; rnd < MPFR_RND_MAX; rnd++)
      {
        if (rnd == MPFR_RNDF)
          continue; /* inexact is undefined */

        mpfr_set_prec (y, q);
        inexact = mpfr_mul_ui (y, x, u, (mpfr_rnd_t) rnd);
        cmp = mpfr_cmp (y, z);
        if (((inexact == 0) && (cmp != 0)) ||
            ((inexact < 0) && (cmp >= 0)) ||
            ((inexact > 0) && (cmp <= 0)))
          {
            printf ("Wrong inexact flag for p=%u, q=%u, rnd=%s\n",
                    (unsigned int) p, (unsigned int) q,
                    mpfr_print_rnd_mode ((mpfr_rnd_t) rnd));
            exit (1);
          }
      }

  mpfr_set_prec (x, 2);
  mpfr_set_ui (x, 1, MPFR_RNDN);
  if (mpfr_mul_ui (x, x, 5, MPFR_RNDZ) == 0)
    {
      printf ("mul_ui(1, 5) cannot be exact with prec=2\n");
      exit (1);
    }

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

#define TEST_FUNCTION mpfr_mul_ui
#define ULONG_ARG2
#define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS)
#include "tgeneric.c"

int
main (int argc, char *argv[])
{
  mpfr_t x, y;
  unsigned int xprec, yprec, i;
  mpfr_prec_t p;
  mpfr_exp_t emax;

  tests_start_mpfr ();

  for (p=2; p<100; p++)
    for (i=1; i<50; i++)
      check_inexact (p);

  mpfr_init2 (x, 53);
  mpfr_init2 (y, 53);

  /* checks that result is normalized */
  mpfr_set_str (y, "6.93147180559945286227e-01", 10, MPFR_RNDZ);
  mpfr_mul_ui (x, y, 1, MPFR_RNDZ);
  if (MPFR_MANT(x)[MPFR_PREC(x)/mp_bits_per_limb] >> (mp_bits_per_limb-1) == 0)
    {
      printf ("Error in mpfr_mul_ui: result not normalized\n");
      exit (1);
    }
  if (mpfr_cmp (x, y))
    {
      printf ("Error in mpfr_mul_ui: 1*y != y\n");
      printf ("y=  "); mpfr_dump (y);
      printf ("1*y="); mpfr_dump (x);
      exit (1);
    }

  mpfr_set_inf (x, 1);
  mpfr_mul_ui (x, x, 3, MPFR_RNDU);
  if (!mpfr_inf_p (x) || (mpfr_sgn (x) <= 0))
    {
      printf ("Error in mpfr_mul_ui: +Inf*3 does not give +Inf\n");
      exit (1);
    }

  mpfr_set_inf (x, -1);
  mpfr_mul_ui (x, x, 3, MPFR_RNDU);
  if (!mpfr_inf_p (x) || (mpfr_sgn (x) >= 0))
    {
      printf ("Error in mpfr_mul_ui: -Inf*3 does not give -Inf\n");
      exit (1);
    }

  mpfr_set_nan (x);
  mpfr_mul_ui (x, x, 3, MPFR_RNDU);
  if (!mpfr_nan_p(x))
    {
      printf ("Error in mpfr_mul_ui: NaN*3 does not give NaN\n");
      exit (1);
    }

  mpfr_set_inf (x, 1);
  mpfr_mul_ui (x, x, 0, MPFR_RNDU);
  MPFR_ASSERTN(mpfr_nan_p (x));

  mpfr_set_ui (x, 1, MPFR_RNDU);
  mpfr_mul_ui (x, x, 0, MPFR_RNDU);
  MPFR_ASSERTN(mpfr_cmp_ui (x, 0) == 0 && MPFR_IS_POS(x));

  emax = mpfr_get_emax ();
  set_emax (0);
  mpfr_set_str_binary (x, "0.1E0");
  (mpfr_mul_ui) (x, x, 2, MPFR_RNDN);
  MPFR_ASSERTN(mpfr_inf_p (x) && MPFR_IS_POS(x));
  set_emax (emax);

  /* To check the macros call */
  mpfr_set_ui (x, 1, MPFR_RNDN);
  mpfr_mul_ui (x, x, 2, MPFR_RNDN);
  MPFR_ASSERTN(mpfr_cmp_ui(x, 2) == 0);
  mpfr_mul_si (x, x, 4, MPFR_RNDN);
  MPFR_ASSERTN(mpfr_cmp_ui(x, 8) == 0);

  mpfr_set_str (x, /*1.0/3.0*/
                "0.333333333333333333333333333333333", 10, MPFR_RNDZ);
  mpfr_mul_ui (x, x, 3, MPFR_RNDU);
  if (mpfr_cmp_ui (x, 1))
    {
      printf ("Error in mpfr_mul_ui: U(Z(1/3)*3) does not give 1\n");
      exit (1);
    }

  /* checks sign is correct */
  mpfr_set_si (x, -2, MPFR_RNDZ);
  mpfr_set_si (y, 3, MPFR_RNDZ);
  mpfr_mul_ui(x, y, 4, MPFR_RNDZ);
  if (mpfr_cmp_ui(x, 0) <= 0)
    {
      printf("Error in mpfr_mul_ui: 4*3.0 does not give a positive result:\n");
      mpfr_dump (x);
      printf("mpfr_cmp_ui(x, 0) = %d\n", mpfr_cmp_ui(x, 0));
      exit(1);
    }

  mpfr_set_prec (x, 9);
  mpfr_set_prec (y, 9);
  mpfr_set_str_binary (y, "0.100001111E9"); /* 271 */
  mpfr_mul_ui (x, y, 1335, MPFR_RNDN);
  mpfr_set_str_binary (y, "0.101100001E19"); /* 361472 */
  if (mpfr_cmp (x, y))
    {
      printf ("Error in mul_ui for 1335*(0.100001111E9)\n");
      printf ("got "); mpfr_dump (x);
      exit(1);
    }

  mpfr_set_prec(y, 100);
  mpfr_set_prec(x, 100);
  /* y = 1199781142214086656 */
  mpfr_set_str_binary(y, "0.1000010100110011110101001011110010101111000100001E61");
  mpfr_mul_ui(x, y, 121, MPFR_RNDD);
  /* 121*y = 145173518207904485376, representable exactly */
  mpfr_set_str_binary(y, "0.1111101111010101111111100011010010111010111110110011001E67");
  if (mpfr_cmp(x, y))
    {
      printf("Error for 121*y: expected result is:\n");
      mpfr_dump (y);
    }

  mpfr_set_prec (x, 32);
  mpfr_set_str_binary (x, "0.10000000000000000000000000000000E1");
  mpfr_set_prec (y, 93);
  mpfr_mul_ui (y, x, 1, MPFR_RNDN);

  mpfr_set_prec (x, 287);
  mpfr_set_str_binary (x, "0.1111E7");
  mpfr_set_prec (y, 289);
  mpfr_mul_ui (y, x, 6, MPFR_RNDN);
  mpfr_set_str_binary (x, "0.101101E10");
  if (mpfr_cmp (x, y))
    {
      printf ("Error for 6 * 120\n");
      exit (1);
    }

  mpfr_set_prec (x, 68);
  mpfr_set_prec (y, 64);
  mpfr_set_str (x, "2143861251406875.0", 10, MPFR_RNDN);
  mpfr_mul_ui (y, x, 23, MPFR_RNDN);
  mpfr_set_str_binary (x, "10101111001011100001100110101111110001010010011001101101.0");
  if (mpfr_cmp (x, y))
    {
      printf ("Error for 23 * 2143861251406875.0\n");
      printf ("expected "); mpfr_dump (x);
      printf ("got      "); mpfr_dump (y);
      exit (1);
    }


  for (xprec = 53; xprec <= 128; xprec++)
    {
      mpfr_set_prec (x, xprec);
      mpfr_set_str_binary (x, "0.1100100100001111110011111000000011011100001100110111E2");
      for (yprec = 53; yprec <= 128; yprec++)
        {
          mpfr_set_prec (y, yprec);
          mpfr_mul_ui (y, x, 1, MPFR_RNDN);
          if (mpfr_cmp(x,y))
            {
              printf ("multiplication by 1.0 fails for xprec=%u, yprec=%u\n",
                      xprec, yprec);
              printf ("expected "); mpfr_dump (x);
              printf ("got      "); mpfr_dump (y);
              exit (1);
            }
        }
    }

  mpfr_set_prec (x, 128);
  mpfr_set_ui (x, 17, MPFR_RNDN);
  mpfr_mul_ui (x, x, ULONG_HIGHBIT, MPFR_RNDN);
  mpfr_set_prec (y, 128);
  mpfr_set_ui (y, ULONG_HIGHBIT, MPFR_RNDN);
  mpfr_mul_ui (y, y, 17, MPFR_RNDN);
  if (mpfr_cmp (x, y))
    {
      printf ("Error for 17 * ULONG_HIGHBIT\n");
      exit (1);
    }

  /* Check regression */
  mpfr_set_prec (x, 32);
  mpfr_set_prec (y, 96);
  mpfr_set_ui (x, 1742175942, MPFR_RNDN);
  mpfr_mul_ui (y, x, 59, MPFR_RNDN);
  if (mpfr_cmp_str (y, "0.10111111011101010101000110111101000100000000000000"
                    "0000000000000000000000000000000000000000000000E37",
                    2, MPFR_RNDN))
    {
      printf ("Regression tested failed for x=1742175942 * 59\n");
      exit (1);
    }

  mpfr_clear(x);
  mpfr_clear(y);

  test_generic (MPFR_PREC_MIN, 500, 100);

  tests_end_mpfr ();
  return 0;
}