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/*
* Copyright (c) 2011, 2012 Nicira, Inc.
*
* 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 "byte-order.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();
}
}
/* Returns the sum of the squares of the first 'n' positive integers. */
static unsigned int
sum_of_squares(int n)
{
return n * (n + 1) * (2 * n + 1) / 6;
}
static void
check_bitwise_copy(void)
{
unsigned int n_loops;
int src_ofs;
int dst_ofs;
int n_bits;
n_loops = 0;
for (n_bits = 0; n_bits <= 64; n_bits++) {
for (src_ofs = 0; src_ofs < 64 - n_bits; src_ofs++) {
for (dst_ofs = 0; dst_ofs < 64 - n_bits; dst_ofs++) {
ovs_be64 src = htonll(random_uint64());
ovs_be64 dst = htonll(random_uint64());
ovs_be64 orig_dst = dst;
ovs_be64 expect;
if (n_bits == 64) {
expect = dst;
} else {
uint64_t mask = (UINT64_C(1) << n_bits) - 1;
expect = orig_dst & ~htonll(mask << dst_ofs);
expect |= htonll(((ntohll(src) >> src_ofs) & mask)
<< dst_ofs);
}
bitwise_copy(&src, sizeof src, src_ofs,
&dst, sizeof dst, dst_ofs,
n_bits);
if (expect != dst) {
fprintf(stderr,"copy_bits(0x%016"PRIx64",8,%d, "
"0x%016"PRIx64",8,%d, %d) yielded 0x%016"PRIx64" "
"instead of the expected 0x%016"PRIx64"\n",
ntohll(src), src_ofs,
ntohll(orig_dst), dst_ofs,
n_bits,
ntohll(dst), ntohll(expect));
abort();
}
n_loops++;
}
}
}
if (n_loops != sum_of_squares(64)) {
abort();
}
}
static void
check_bitwise_zero(void)
{
unsigned int n_loops;
int dst_ofs;
int n_bits;
n_loops = 0;
for (n_bits = 0; n_bits <= 64; n_bits++) {
for (dst_ofs = 0; dst_ofs < 64 - n_bits; dst_ofs++) {
ovs_be64 dst = htonll(random_uint64());
ovs_be64 orig_dst = dst;
ovs_be64 expect;
if (n_bits == 64) {
expect = htonll(0);
} else {
uint64_t mask = (UINT64_C(1) << n_bits) - 1;
expect = orig_dst & ~htonll(mask << dst_ofs);
}
bitwise_zero(&dst, sizeof dst, dst_ofs, n_bits);
if (expect != dst) {
fprintf(stderr,"bitwise_zero(0x%016"PRIx64",8,%d, %d) "
"yielded 0x%016"PRIx64" "
"instead of the expected 0x%016"PRIx64"\n",
ntohll(orig_dst), dst_ofs,
n_bits,
ntohll(dst), ntohll(expect));
abort();
}
n_loops++;
}
}
if (n_loops != 64 * (64 + 1) / 2) {
abort();
}
}
static void
check_bitwise_one(void)
{
unsigned int n_loops;
int dst_ofs;
int n_bits;
n_loops = 0;
for (n_bits = 0; n_bits <= 64; n_bits++) {
for (dst_ofs = 0; dst_ofs < 64 - n_bits; dst_ofs++) {
ovs_be64 dst = htonll(random_uint64());
ovs_be64 orig_dst = dst;
ovs_be64 expect;
if (n_bits == 64) {
expect = htonll(UINT64_MAX);
} else {
uint64_t mask = (UINT64_C(1) << n_bits) - 1;
expect = orig_dst | htonll(mask << dst_ofs);
}
bitwise_one(&dst, sizeof dst, dst_ofs, n_bits);
if (expect != dst) {
fprintf(stderr,"bitwise_one(0x%016"PRIx64",8,%d, %d) "
"yielded 0x%016"PRIx64" "
"instead of the expected 0x%016"PRIx64"\n",
ntohll(orig_dst), dst_ofs,
n_bits,
ntohll(dst), ntohll(expect));
abort();
}
n_loops++;
}
}
if (n_loops != 64 * (64 + 1) / 2) {
abort();
}
}
static void
check_bitwise_is_all_zeros(void)
{
int n_loops;
n_loops = 0;
for (n_loops = 0; n_loops < 100; n_loops++) {
ovs_be64 x = htonll(0);
int i;
for (i = 0; i < 64; i++) {
ovs_be64 bit;
int ofs, n;
/* Change a random 0-bit into a 1-bit. */
do {
bit = htonll(UINT64_C(1) << (random_uint32() % 64));
} while (x & bit);
x |= bit;
for (ofs = 0; ofs < 64; ofs++) {
for (n = 0; n <= 64 - ofs; n++) {
bool expect;
bool answer;
expect = (n == 64
? x == 0
: !(x & htonll(((UINT64_C(1) << n) - 1)
<< ofs)));
answer = bitwise_is_all_zeros(&x, sizeof x, ofs, n);
if (expect != answer) {
fprintf(stderr,
"bitwise_is_all_zeros(0x%016"PRIx64",8,%d,%d "
"returned %s instead of %s\n",
ntohll(x), ofs, n,
answer ? "true" : "false",
expect ? "true" : "false");
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);
check_bitwise_copy();
check_bitwise_zero();
check_bitwise_one();
check_bitwise_is_all_zeros();
return 0;
}
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