kc3-lang/gnulib/tests/test-count-trailing-zeros.c

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• Hash : 7b089321
  Author :
  Date : 2025-01-01T09:24:36
  

  maint: run 'make update-copyright'
  

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• tests/test-count-trailing-zeros.c

• /* Test counting of trailing zeros.
     Copyright (C) 2013-2025 Free Software Foundation, Inc.
  
     This program 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.
  
     This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */
  
  /* Written by Paul Eggert.  */
  
  #include <config.h>
  
  #include "count-trailing-zeros.h"
  
  #include <limits.h>
  #include <stdio.h>
  
  #include "macros.h"
  
  #define UINT_BIT (sizeof (unsigned int) * CHAR_BIT)
  #define ULONG_BIT (sizeof (unsigned long int) * CHAR_BIT)
  #define ULLONG_BIT (sizeof (unsigned long long int) * CHAR_BIT)
  
  int
  main (int argc, char *argv[])
  {
    int i, j;
  
  #define TEST_COUNT_TRAILING_ZEROS(FUNC, TYPE, BITS, MAX, ONE) \
    ASSERT (FUNC (0) == BITS);                                  \
    for (i = 0; i < BITS; i++)                                  \
      {                                                         \
        ASSERT (FUNC (ONE << i) == i);                          \
        for (j = 0; j < i; j++)                                 \
          ASSERT (FUNC ((ONE << i) | (ONE << j)) == j);         \
      }                                                         \
    for (i = 0; i < 1000; i++)                                  \
      {                                                         \
        /* RAND_MAX is most often 0x7fff or 0x7fffffff.  */     \
        TYPE value =                                            \
          (RAND_MAX <= 0xffff                                   \
           ? ((TYPE) rand () >> 3)                              \
             ^ (((TYPE) rand () >> 3) << 12)                    \
             ^ (((TYPE) rand () >> 3) << 24)                    \
             ^ (((TYPE) rand () >> 3) << 30 << 6)               \
             ^ (((TYPE) rand () >> 3) << 30 << 18)              \
             ^ (((TYPE) rand () >> 3) << 30 << 30)              \
           : ((TYPE) rand () >> 3)                              \
             ^ (((TYPE) rand () >> 3) << 22)                    \
             ^ (((TYPE) rand () >> 3) << 22 << 22));            \
        int count = 0;                                          \
        for (j = BITS - 1; 0 <= j; j--)                         \
          if (value & (ONE << j))                               \
            count = j;                                          \
        ASSERT (count == FUNC (value));                         \
      }                                                         \
    ASSERT (FUNC (MAX) == 0);
  
    TEST_COUNT_TRAILING_ZEROS (count_trailing_zeros, unsigned int,
                               UINT_BIT, UINT_MAX, 1U);
    TEST_COUNT_TRAILING_ZEROS (count_trailing_zeros_l, unsigned long int,
                               ULONG_BIT, ULONG_MAX, 1UL);
    TEST_COUNT_TRAILING_ZEROS (count_trailing_zeros_ll, unsigned long long int,
                               ULLONG_BIT, ULLONG_MAX, 1ULL);
  
    return test_exit_status;
  }
  

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