bits_test.cc (3048B)
1 // Copyright (c) the JPEG XL Project Authors. All rights reserved. 2 // 3 // Use of this source code is governed by a BSD-style 4 // license that can be found in the LICENSE file. 5 6 #include "lib/jxl/base/bits.h" 7 8 #include "lib/jxl/testing.h" 9 10 namespace jxl { 11 namespace { 12 13 TEST(BitsTest, TestNumZeroBits) { 14 // Zero input is well-defined. 15 EXPECT_EQ(32u, Num0BitsAboveMS1Bit(0u)); 16 EXPECT_EQ(64u, Num0BitsAboveMS1Bit(0ull)); 17 EXPECT_EQ(32u, Num0BitsBelowLS1Bit(0u)); 18 EXPECT_EQ(64u, Num0BitsBelowLS1Bit(0ull)); 19 20 EXPECT_EQ(31u, Num0BitsAboveMS1Bit(1u)); 21 EXPECT_EQ(30u, Num0BitsAboveMS1Bit(2u)); 22 EXPECT_EQ(63u, Num0BitsAboveMS1Bit(1ull)); 23 EXPECT_EQ(62u, Num0BitsAboveMS1Bit(2ull)); 24 25 EXPECT_EQ(0u, Num0BitsBelowLS1Bit(1u)); 26 EXPECT_EQ(0u, Num0BitsBelowLS1Bit(1ull)); 27 EXPECT_EQ(1u, Num0BitsBelowLS1Bit(2u)); 28 EXPECT_EQ(1u, Num0BitsBelowLS1Bit(2ull)); 29 30 EXPECT_EQ(0u, Num0BitsAboveMS1Bit(0x80000000u)); 31 EXPECT_EQ(0u, Num0BitsAboveMS1Bit(0x8000000000000000ull)); 32 EXPECT_EQ(31u, Num0BitsBelowLS1Bit(0x80000000u)); 33 EXPECT_EQ(63u, Num0BitsBelowLS1Bit(0x8000000000000000ull)); 34 } 35 36 TEST(BitsTest, TestFloorLog2) { 37 // for input = [1, 7] 38 const size_t expected[7] = {0, 1, 1, 2, 2, 2, 2}; 39 for (uint32_t i = 1; i <= 7; ++i) { 40 EXPECT_EQ(expected[i - 1], FloorLog2Nonzero(i)) << " " << i; 41 EXPECT_EQ(expected[i - 1], FloorLog2Nonzero(static_cast<uint64_t>(i))) 42 << " " << i; 43 } 44 45 EXPECT_EQ(11u, FloorLog2Nonzero(0x00000fffu)); // 4095 46 EXPECT_EQ(12u, FloorLog2Nonzero(0x00001000u)); // 4096 47 EXPECT_EQ(12u, FloorLog2Nonzero(0x00001001u)); // 4097 48 49 EXPECT_EQ(31u, FloorLog2Nonzero(0x80000000u)); 50 EXPECT_EQ(31u, FloorLog2Nonzero(0x80000001u)); 51 EXPECT_EQ(31u, FloorLog2Nonzero(0xFFFFFFFFu)); 52 53 EXPECT_EQ(31u, FloorLog2Nonzero(0x80000000ull)); 54 EXPECT_EQ(31u, FloorLog2Nonzero(0x80000001ull)); 55 EXPECT_EQ(31u, FloorLog2Nonzero(0xFFFFFFFFull)); 56 57 EXPECT_EQ(63u, FloorLog2Nonzero(0x8000000000000000ull)); 58 EXPECT_EQ(63u, FloorLog2Nonzero(0x8000000000000001ull)); 59 EXPECT_EQ(63u, FloorLog2Nonzero(0xFFFFFFFFFFFFFFFFull)); 60 } 61 62 TEST(BitsTest, TestCeilLog2) { 63 // for input = [1, 7] 64 const size_t expected[7] = {0, 1, 2, 2, 3, 3, 3}; 65 for (uint32_t i = 1; i <= 7; ++i) { 66 EXPECT_EQ(expected[i - 1], CeilLog2Nonzero(i)) << " " << i; 67 EXPECT_EQ(expected[i - 1], CeilLog2Nonzero(static_cast<uint64_t>(i))) 68 << " " << i; 69 } 70 71 EXPECT_EQ(12u, CeilLog2Nonzero(0x00000fffu)); // 4095 72 EXPECT_EQ(12u, CeilLog2Nonzero(0x00001000u)); // 4096 73 EXPECT_EQ(13u, CeilLog2Nonzero(0x00001001u)); // 4097 74 75 EXPECT_EQ(31u, CeilLog2Nonzero(0x80000000u)); 76 EXPECT_EQ(32u, CeilLog2Nonzero(0x80000001u)); 77 EXPECT_EQ(32u, CeilLog2Nonzero(0xFFFFFFFFu)); 78 79 EXPECT_EQ(31u, CeilLog2Nonzero(0x80000000ull)); 80 EXPECT_EQ(32u, CeilLog2Nonzero(0x80000001ull)); 81 EXPECT_EQ(32u, CeilLog2Nonzero(0xFFFFFFFFull)); 82 83 EXPECT_EQ(63u, CeilLog2Nonzero(0x8000000000000000ull)); 84 EXPECT_EQ(64u, CeilLog2Nonzero(0x8000000000000001ull)); 85 EXPECT_EQ(64u, CeilLog2Nonzero(0xFFFFFFFFFFFFFFFFull)); 86 } 87 88 } // namespace 89 } // namespace jxl