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/* Test of integer_length().
Copyright (C) 2011-2023 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/>. */
#include <config.h>
#include "integer_length.h"
#include <limits.h>
#include "macros.h"
#define NBITS (sizeof (unsigned int) * CHAR_BIT)
static int
naive (unsigned int x)
{
int j;
for (j = NBITS - 1; j >= 0; j--)
if (x & (1U << j))
return j + 1;
return 0;
}
int
main (int argc, char *argv[])
{
unsigned int x;
int i;
for (x = 0; x <= 256; x++)
ASSERT (integer_length (x) == naive (x));
for (i = 0; i < NBITS; i++)
{
ASSERT (integer_length (1U << i) == naive (1U << i));
ASSERT (integer_length (1U << i) == i + 1);
ASSERT (integer_length (-1U << i) == NBITS);
}
for (i = 0; i < NBITS - 1; i++)
ASSERT (integer_length (3U << i) == i + 2);
for (i = 0; i < NBITS - 2; i++)
ASSERT (integer_length (-3U << i) == NBITS);
for (i = 0; i < NBITS - 2; i++)
{
ASSERT (integer_length (5U << i) == i + 3);
ASSERT (integer_length (7U << i) == i + 3);
}
for (i = 0; i < NBITS - 3; i++)
{
ASSERT (integer_length (-5U << i) == NBITS);
ASSERT (integer_length (-7U << i) == NBITS);
}
return 0;
}
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