1 /*
2 * Copyright (c) 2018, Alliance for Open Media. All rights reserved.
3 *
4 * This source code is subject to the terms of the BSD 2 Clause License and
5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6 * was not distributed with this source code in the LICENSE file, you can
7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8 * Media Patent License 1.0 was not distributed with this source code in the
9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10 */
11
12 #include <limits.h>
13 #include <math.h>
14
15 #include "aom_ports/bitops.h"
16 #include "av1/common/entropymode.h"
17 #include "gtest/gtest.h"
18
TEST(Log2Test,GetMsb)19 TEST(Log2Test, GetMsb) {
20 // Test small numbers exhaustively.
21 for (unsigned int n = 1; n < 10000; n++) {
22 EXPECT_EQ(get_msb(n), static_cast<int>(floor(log2(n))));
23 }
24
25 // Test every power of 2 and the two adjacent numbers.
26 for (int exponent = 2; exponent < 32; exponent++) {
27 const unsigned int power_of_2 = 1U << exponent;
28 EXPECT_EQ(get_msb(power_of_2 - 1), exponent - 1);
29 EXPECT_EQ(get_msb(power_of_2), exponent);
30 EXPECT_EQ(get_msb(power_of_2 + 1), exponent);
31 }
32 }
33
TEST(Log2Test,Av1CeilLog2)34 TEST(Log2Test, Av1CeilLog2) {
35 // Test small numbers exhaustively.
36 EXPECT_EQ(av1_ceil_log2(0), 0);
37 for (int n = 1; n < 10000; n++) {
38 EXPECT_EQ(av1_ceil_log2(n), static_cast<int>(ceil(log2(n))));
39 }
40
41 // Test every power of 2 and the two adjacent numbers.
42 for (int exponent = 2; exponent < 31; exponent++) {
43 const int power_of_2 = 1 << exponent;
44 EXPECT_EQ(av1_ceil_log2(power_of_2 - 1), exponent);
45 EXPECT_EQ(av1_ceil_log2(power_of_2), exponent);
46 EXPECT_EQ(av1_ceil_log2(power_of_2 + 1), exponent + 1);
47 }
48
49 // INT_MAX = 2^31 - 1
50 EXPECT_EQ(av1_ceil_log2(INT_MAX), 31);
51 }
52