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/*
* Copyright (c) 2011 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include "random.h"
#include "util.h"
static void
check_log_2_floor(uint32_t x, int n)
{
if (log_2_floor(x) != n) {
fprintf(stderr, "log_2_floor(%"PRIu32") is %d but should be %d\n",
x, log_2_floor(x), n);
abort();
}
}
static void
check_ctz(uint32_t x, int n)
{
if (ctz(x) != n) {
fprintf(stderr, "ctz(%"PRIu32") is %d but should be %d\n",
x, ctz(x), n);
abort();
}
}
int
main(void)
{
int n;
for (n = 0; n < 32; n++) {
/* Check minimum x such that f(x) == n. */
check_log_2_floor(1 << n, n);
check_ctz(1 << n, n);
/* Check maximum x such that f(x) == n. */
check_log_2_floor((1 << n) | ((1 << n) - 1), n);
check_ctz(UINT32_MAX << n, n);
/* Check a random value in the middle. */
check_log_2_floor((random_uint32() & ((1 << n) - 1)) | (1 << n), n);
check_ctz((random_uint32() | 1) << n, n);
}
/* Check ctz(0).
* (log_2_floor(0) is undefined.) */
check_ctz(0, 32);
return 0;
}
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