test/log2_test.cc

   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 <math.h>
  13
  14 #include "aom_ports/bitops.h"
  15 #include "av1/common/entropymode.h"
  16 #include "third_party/googletest/src/googletest/include/gtest/gtest.h"
  17
  18 TEST(Log2Test, GetMsb) {
  19   // Test small numbers exhaustively.
  20   for (unsigned int n = 1; n < 10000; n++) {
  21     EXPECT_EQ(get_msb(n), static_cast<int>(floor(log2(n))));
  22   }
  23
  24   // Test every power of 2 and the two adjacent numbers.
  25   for (int exponent = 2; exponent < 32; exponent++) {
  26     const unsigned int power_of_2 = 1U << exponent;
  27     EXPECT_EQ(get_msb(power_of_2 - 1), exponent - 1);
  28     EXPECT_EQ(get_msb(power_of_2), exponent);
  29     EXPECT_EQ(get_msb(power_of_2 + 1), exponent);
  30   }
  31 }
  32
  33 TEST(Log2Test, Av1CeilLog2) {
  34   // Test small numbers exhaustively.
  35   EXPECT_EQ(av1_ceil_log2(0), 0);
  36   for (int n = 1; n < 10000; n++) {
  37     EXPECT_EQ(av1_ceil_log2(n), static_cast<int>(ceil(log2(n))));
  38   }
  39
  40   // Test every power of 2 and the two adjacent numbers.
  41   for (int exponent = 2; exponent < 31; exponent++) {
  42     const int power_of_2 = 1 << exponent;
  43     EXPECT_EQ(av1_ceil_log2(power_of_2 - 1), exponent);
  44     EXPECT_EQ(av1_ceil_log2(power_of_2), exponent);
  45     // The current implementation of av1_ceil_log2 only works up to 2^30.
  46     if (exponent < 30) {
  47       EXPECT_EQ(av1_ceil_log2(power_of_2 + 1), exponent + 1);
  48     }
  49   }
  50 }