1  /* Test file for mpfr_mul_d
       2  
       3  Copyright 2007-2023 Free Software Foundation, Inc.
       4  Contributed by the AriC and Caramba projects, INRIA.
       5  
       6  This file is part of the GNU MPFR Library.
       7  
       8  The GNU MPFR Library is free software; you can redistribute it and/or modify
       9  it under the terms of the GNU Lesser General Public License as published by
      10  the Free Software Foundation; either version 3 of the License, or (at your
      11  option) any later version.
      12  
      13  The GNU MPFR Library is distributed in the hope that it will be useful, but
      14  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
      15  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
      16  License for more details.
      17  
      18  You should have received a copy of the GNU Lesser General Public License
      19  along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
      20  https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
      21  51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
      22  
      23  #include <float.h>
      24  
      25  #include "mpfr-test.h"
      26  
      27  static void
      28  check_nans (void)
      29  {
      30    mpfr_t  x, y;
      31    int inexact;
      32  
      33    mpfr_init2 (x, 123);
      34    mpfr_init2 (y, 123);
      35  
      36    /* nan * 1.0 is nan */
      37    mpfr_set_nan (x);
      38    mpfr_clear_flags();
      39    inexact = mpfr_mul_d (y, x, 1.0, MPFR_RNDN);
      40    MPFR_ASSERTN (inexact == 0);
      41    MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_NAN);
      42    MPFR_ASSERTN (mpfr_nan_p (y));
      43  
      44    /* +inf * 1.0 == +inf */
      45    mpfr_set_inf (x, 1);
      46    mpfr_clear_flags();
      47    inexact = mpfr_mul_d (y, x, 1.0, MPFR_RNDN);
      48    MPFR_ASSERTN (inexact == 0);
      49    MPFR_ASSERTN (__gmpfr_flags == 0);
      50    MPFR_ASSERTN (mpfr_inf_p (y));
      51    MPFR_ASSERTN (MPFR_IS_POS (y));
      52  
      53    /* +inf * 0.0 is nan */
      54    mpfr_clear_flags();
      55    inexact = mpfr_mul_d (y, x, 0.0, MPFR_RNDN);
      56    MPFR_ASSERTN (inexact == 0);
      57    MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_NAN);
      58    MPFR_ASSERTN (mpfr_nan_p (y));
      59  
      60    /* -inf * 1.0 == -inf */
      61    mpfr_set_inf (x, -1);
      62    mpfr_clear_flags();
      63    inexact = mpfr_mul_d (y, x, 1.0, MPFR_RNDN);
      64    MPFR_ASSERTN (inexact == 0);
      65    MPFR_ASSERTN (__gmpfr_flags == 0);
      66    MPFR_ASSERTN (mpfr_inf_p (y));
      67    MPFR_ASSERTN (MPFR_IS_NEG (y));
      68  
      69    mpfr_clear (x);
      70    mpfr_clear (y);
      71  }
      72  
      73  static void
      74  bug20171218 (void)
      75  {
      76    mpfr_t a, b;
      77    mpfr_init2 (a, 22);
      78    mpfr_init2 (b, 1312);
      79    mpfr_set_str (b, "1.ffffffffffffffffffc3e0007ffe000700fff8001fff800000000007e0fffe0007fffffff00001f800000003ffffffe1fc00000003fffe7c03ffffffffffffffe000000fffffffff83f0000007ffc03ffffffffc0007ff0000ffcfffffe00000f80000000003c007ffffffff3ff807ffffffffff000000000000001fc000fffe000600000ff0003ffe00fffffffc00001ffc0fffffffffff00000807fe03ffffffc01ffe", 16, MPFR_RNDN);
      80    mpfr_mul_d (a, b, 0.5, MPFR_RNDF);
      81    /* a should be 1 or nextbelow(1) */
      82    if (mpfr_cmp_ui (a, 1) != 0)
      83      {
      84        mpfr_nextabove (a);
      85        MPFR_ASSERTN(mpfr_cmp_ui (a, 1) == 0);
      86      }
      87    mpfr_clear (a);
      88    mpfr_clear (b);
      89  }
      90  
      91  #define TEST_FUNCTION mpfr_mul_d
      92  #define DOUBLE_ARG2
      93  #define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS)
      94  #include "tgeneric.c"
      95  
      96  int
      97  main (void)
      98  {
      99    mpfr_t x, y, z;
     100    double d;
     101    int inexact;
     102  
     103    tests_start_mpfr ();
     104  
     105    bug20171218 ();
     106  
     107    /* check with enough precision */
     108    mpfr_init2 (x, IEEE_DBL_MANT_DIG);
     109    mpfr_init2 (y, IEEE_DBL_MANT_DIG);
     110    mpfr_init2 (z, IEEE_DBL_MANT_DIG);
     111  
     112    mpfr_set_str (y, "4096", 10, MPFR_RNDN);
     113    d = 0.125;
     114    mpfr_clear_flags ();
     115    inexact = mpfr_mul_d (x, y, d, MPFR_RNDN);
     116    if (inexact != 0)
     117      {
     118        printf ("Inexact flag error in mpfr_mul_d\n");
     119        exit (1);
     120      }
     121    mpfr_set_str (z, "512", 10, MPFR_RNDN);
     122    if (mpfr_cmp (z, x))
     123      {
     124        printf ("Error in mpfr_mul_d (");
     125        mpfr_out_str (stdout, 10, 0, y, MPFR_RNDN);
     126        printf (" + %.20g)\nexpected ", d);
     127        mpfr_out_str (stdout, 10, 0, z, MPFR_RNDN);
     128        printf ("\ngot     ");
     129        mpfr_out_str (stdout, 10, 0, x, MPFR_RNDN);
     130        printf ("\n");
     131        exit (1);
     132      }
     133    mpfr_clears (x, y, z, (mpfr_ptr) 0);
     134  
     135    check_nans ();
     136  
     137    test_generic (MPFR_PREC_MIN, 1000, 100);
     138  
     139    tests_end_mpfr ();
     140    return 0;
     141  }