1/*
2 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#include "precompiled.hpp"
26#include "utilities/count_leading_zeros.hpp"
27#include "utilities/globalDefinitions.hpp"
28#include "unittest.hpp"
29
30TEST(count_leading_zeros, one_or_two_set_bits) {
31 unsigned i = 0; // Position of a set bit.
32 for (uint32_t ix = 1; ix != 0; ix <<= 1, ++i) {
33 unsigned j = 0; // Position of a set bit.
34 for (uint32_t jx = 1; jx != 0; jx <<= 1, ++j) {
35 uint32_t value = ix | jx;
36 EXPECT_EQ(31u - MAX2(i, j), count_leading_zeros(value))
37 << "value = " << value;
38 }
39 }
40}
41
42TEST(count_leading_zeros, high_zeros_low_ones) {
43 unsigned i = 0; // Number of leading zeros
44 uint32_t value = ~(uint32_t)0;
45 for ( ; value != 0; value >>= 1, ++i) {
46 EXPECT_EQ(i, count_leading_zeros(value))
47 << "value = " << value;
48 }
49}
50
51TEST(count_leading_zeros, high_ones_low_zeros) {
52 uint32_t value = ~(uint32_t)0;
53 for ( ; value != 0; value <<= 1) {
54 EXPECT_EQ(0u, count_leading_zeros(value))
55 << "value = " << value;
56 }
57}
58