1 //===-- Unittests for math_extras -----------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "src/__support/integer_literals.h" 10 #include "src/__support/macros/config.h" 11 #include "src/__support/math_extras.h" 12 #include "src/__support/uint128.h" // UInt<128> 13 #include "test/UnitTest/Test.h" 14 15 namespace LIBC_NAMESPACE_DECL { 16 17 // TODO: add UInt<128> support. 18 using UnsignedTypesNoBigInt = testing::TypeList< 19 #if defined(LIBC_TYPES_HAS_INT128) 20 __uint128_t, 21 #endif // LIBC_TYPES_HAS_INT128 22 unsigned char, unsigned short, unsigned int, unsigned long, 23 unsigned long long, UInt<128>>; 24 25 TEST(LlvmLibcBlockMathExtrasTest, mask_trailing_ones) { 26 EXPECT_EQ(0_u8, (mask_leading_ones<uint8_t, 0>())); 27 EXPECT_EQ(0_u8, (mask_trailing_ones<uint8_t, 0>())); 28 EXPECT_EQ(0_u16, (mask_leading_ones<uint16_t, 0>())); 29 EXPECT_EQ(0_u16, (mask_trailing_ones<uint16_t, 0>())); 30 EXPECT_EQ(0_u32, (mask_leading_ones<uint32_t, 0>())); 31 EXPECT_EQ(0_u32, (mask_trailing_ones<uint32_t, 0>())); 32 EXPECT_EQ(0_u64, (mask_leading_ones<uint64_t, 0>())); 33 EXPECT_EQ(0_u64, (mask_trailing_ones<uint64_t, 0>())); 34 35 EXPECT_EQ(0x00000003_u32, (mask_trailing_ones<uint32_t, 2>())); 36 EXPECT_EQ(0xC0000000_u32, (mask_leading_ones<uint32_t, 2>())); 37 38 EXPECT_EQ(0x000007FF_u32, (mask_trailing_ones<uint32_t, 11>())); 39 EXPECT_EQ(0xFFE00000_u32, (mask_leading_ones<uint32_t, 11>())); 40 41 EXPECT_EQ(0xFFFFFFFF_u32, (mask_trailing_ones<uint32_t, 32>())); 42 EXPECT_EQ(0xFFFFFFFF_u32, (mask_leading_ones<uint32_t, 32>())); 43 EXPECT_EQ(0xFFFFFFFFFFFFFFFF_u64, (mask_trailing_ones<uint64_t, 64>())); 44 EXPECT_EQ(0xFFFFFFFFFFFFFFFF_u64, (mask_leading_ones<uint64_t, 64>())); 45 46 EXPECT_EQ(0x0000FFFFFFFFFFFF_u64, (mask_trailing_ones<uint64_t, 48>())); 47 EXPECT_EQ(0xFFFFFFFFFFFF0000_u64, (mask_leading_ones<uint64_t, 48>())); 48 49 EXPECT_EQ(0_u128, (mask_trailing_ones<UInt128, 0>())); 50 EXPECT_EQ(0_u128, (mask_leading_ones<UInt128, 0>())); 51 52 EXPECT_EQ(0x00000000000000007FFFFFFFFFFFFFFF_u128, 53 (mask_trailing_ones<UInt128, 63>())); 54 EXPECT_EQ(0xFFFFFFFFFFFFFFFE0000000000000000_u128, 55 (mask_leading_ones<UInt128, 63>())); 56 57 EXPECT_EQ(0x0000000000000000FFFFFFFFFFFFFFFF_u128, 58 (mask_trailing_ones<UInt128, 64>())); 59 EXPECT_EQ(0xFFFFFFFFFFFFFFFF0000000000000000_u128, 60 (mask_leading_ones<UInt128, 64>())); 61 62 EXPECT_EQ(0x0000000000000001FFFFFFFFFFFFFFFF_u128, 63 (mask_trailing_ones<UInt128, 65>())); 64 EXPECT_EQ(0xFFFFFFFFFFFFFFFF8000000000000000_u128, 65 (mask_leading_ones<UInt128, 65>())); 66 67 EXPECT_EQ(0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF_u128, 68 (mask_trailing_ones<UInt128, 128>())); 69 EXPECT_EQ(0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF_u128, 70 (mask_leading_ones<UInt128, 128>())); 71 } 72 73 TYPED_TEST(LlvmLibcBitTest, FirstLeadingZero, UnsignedTypesNoBigInt) { 74 EXPECT_EQ(first_leading_zero<T>(cpp::numeric_limits<T>::max()), 0); 75 for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i) 76 EXPECT_EQ(first_leading_zero<T>(~(T(1) << i)), 77 cpp::numeric_limits<T>::digits - i); 78 } 79 80 TYPED_TEST(LlvmLibcBitTest, FirstLeadingOne, UnsignedTypesNoBigInt) { 81 EXPECT_EQ(first_leading_one<T>(static_cast<T>(0)), 0); 82 for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i) 83 EXPECT_EQ(first_leading_one<T>(T(1) << i), 84 cpp::numeric_limits<T>::digits - i); 85 } 86 87 TYPED_TEST(LlvmLibcBitTest, FirstTrailingZero, UnsignedTypesNoBigInt) { 88 EXPECT_EQ(first_trailing_zero<T>(cpp::numeric_limits<T>::max()), 0); 89 for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i) 90 EXPECT_EQ(first_trailing_zero<T>(~(T(1) << i)), i + 1); 91 } 92 93 TYPED_TEST(LlvmLibcBitTest, FirstTrailingOne, UnsignedTypesNoBigInt) { 94 EXPECT_EQ(first_trailing_one<T>(cpp::numeric_limits<T>::max()), 0); 95 for (int i = 0U; i != cpp::numeric_limits<T>::digits; ++i) 96 EXPECT_EQ(first_trailing_one<T>(T(1) << i), i + 1); 97 } 98 99 TYPED_TEST(LlvmLibcBitTest, CountZeros, UnsignedTypesNoBigInt) { 100 EXPECT_EQ(count_zeros(T(0)), cpp::numeric_limits<T>::digits); 101 for (int i = 0; i != cpp::numeric_limits<T>::digits; ++i) 102 EXPECT_EQ(count_zeros<T>(cpp::numeric_limits<T>::max() >> i), i); 103 } 104 105 using UnsignedTypes = testing::TypeList< 106 #if defined(LIBC_TYPES_HAS_INT128) 107 __uint128_t, 108 #endif 109 unsigned char, unsigned short, unsigned int, unsigned long, 110 unsigned long long>; 111 112 TYPED_TEST(LlvmLibcBlockMathExtrasTest, add_overflow, UnsignedTypes) { 113 constexpr T ZERO = cpp::numeric_limits<T>::min(); 114 constexpr T ONE(1); 115 constexpr T MAX = cpp::numeric_limits<T>::max(); 116 constexpr T BEFORE_MAX = MAX - 1; 117 118 const struct { 119 T lhs; 120 T rhs; 121 T sum; 122 bool carry; 123 } TESTS[] = { 124 {ZERO, ONE, ONE, false}, // 0x00 + 0x01 = 0x01 125 {BEFORE_MAX, ONE, MAX, false}, // 0xFE + 0x01 = 0xFF 126 {MAX, ONE, ZERO, true}, // 0xFF + 0x01 = 0x00 (carry) 127 {MAX, MAX, BEFORE_MAX, true}, // 0xFF + 0xFF = 0xFE (carry) 128 }; 129 for (auto tc : TESTS) { 130 T sum; 131 bool carry = add_overflow<T>(tc.lhs, tc.rhs, sum); 132 EXPECT_EQ(sum, tc.sum); 133 EXPECT_EQ(carry, tc.carry); 134 } 135 } 136 137 TYPED_TEST(LlvmLibcBlockMathExtrasTest, sub_overflow, UnsignedTypes) { 138 constexpr T ZERO = cpp::numeric_limits<T>::min(); 139 constexpr T ONE(1); 140 constexpr T MAX = cpp::numeric_limits<T>::max(); 141 constexpr T BEFORE_MAX = MAX - 1; 142 143 const struct { 144 T lhs; 145 T rhs; 146 T sub; 147 bool carry; 148 } TESTS[] = { 149 {ONE, ZERO, ONE, false}, // 0x01 - 0x00 = 0x01 150 {MAX, MAX, ZERO, false}, // 0xFF - 0xFF = 0x00 151 {ZERO, ONE, MAX, true}, // 0x00 - 0x01 = 0xFF (carry) 152 {BEFORE_MAX, MAX, MAX, true}, // 0xFE - 0xFF = 0xFF (carry) 153 }; 154 for (auto tc : TESTS) { 155 T sub; 156 bool carry = sub_overflow<T>(tc.lhs, tc.rhs, sub); 157 EXPECT_EQ(sub, tc.sub); 158 EXPECT_EQ(carry, tc.carry); 159 } 160 } 161 162 } // namespace LIBC_NAMESPACE_DECL 163