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Diffstat (limited to 'absl/numeric/int128_test.cc')
| -rw-r--r-- | absl/numeric/int128_test.cc | 743 |
1 files changed, 743 insertions, 0 deletions
diff --git a/absl/numeric/int128_test.cc b/absl/numeric/int128_test.cc index 5e1b5ec352b0..bc86c714acce 100644 --- a/absl/numeric/int128_test.cc +++ b/absl/numeric/int128_test.cc @@ -479,4 +479,747 @@ TEST(Uint128, Hash) { })); } + +TEST(Int128Uint128, ConversionTest) { + absl::int128 nonnegative_signed_values[] = { + 0, + 1, + 0xffeeddccbbaa9988, + absl::MakeInt128(0x7766554433221100, 0), + absl::MakeInt128(0x1234567890abcdef, 0xfedcba0987654321), + absl::Int128Max()}; + for (absl::int128 value : nonnegative_signed_values) { + EXPECT_EQ(value, absl::int128(absl::uint128(value))); + + absl::uint128 assigned_value; + assigned_value = value; + EXPECT_EQ(value, absl::int128(assigned_value)); + } + + absl::int128 negative_values[] = { + -1, -0x1234567890abcdef, + absl::MakeInt128(-0x5544332211ffeedd, 0), + -absl::MakeInt128(0x76543210fedcba98, 0xabcdef0123456789)}; + for (absl::int128 value : negative_values) { + EXPECT_EQ(absl::uint128(-value), -absl::uint128(value)); + + absl::uint128 assigned_value; + assigned_value = value; + EXPECT_EQ(absl::uint128(-value), -assigned_value); + } +} + +template <typename T> +class Int128IntegerTraitsTest : public ::testing::Test {}; + +TYPED_TEST_SUITE(Int128IntegerTraitsTest, IntegerTypes); + +TYPED_TEST(Int128IntegerTraitsTest, ConstructAssignTest) { + static_assert(std::is_constructible<absl::int128, TypeParam>::value, + "absl::int128 must be constructible from TypeParam"); + static_assert(std::is_assignable<absl::int128&, TypeParam>::value, + "absl::int128 must be assignable from TypeParam"); + static_assert(!std::is_assignable<TypeParam&, absl::int128>::value, + "TypeParam must not be assignable from absl::int128"); +} + +template <typename T> +class Int128FloatTraitsTest : public ::testing::Test {}; + +TYPED_TEST_SUITE(Int128FloatTraitsTest, FloatingPointTypes); + +TYPED_TEST(Int128FloatTraitsTest, ConstructAssignTest) { + static_assert(std::is_constructible<absl::int128, TypeParam>::value, + "absl::int128 must be constructible from TypeParam"); + static_assert(!std::is_assignable<absl::int128&, TypeParam>::value, + "absl::int128 must not be assignable from TypeParam"); + static_assert(!std::is_assignable<TypeParam&, absl::int128>::value, + "TypeParam must not be assignable from absl::int128"); +} + +#ifdef ABSL_HAVE_INTRINSIC_INT128 +// These type traits done separately as TYPED_TEST requires typeinfo, and not +// all platforms have this for __int128 even though they define the type. +TEST(Int128, IntrinsicTypeTraitsTest) { + static_assert(std::is_constructible<absl::int128, __int128>::value, + "absl::int128 must be constructible from __int128"); + static_assert(std::is_assignable<absl::int128&, __int128>::value, + "absl::int128 must be assignable from __int128"); + static_assert(!std::is_assignable<__int128&, absl::int128>::value, + "__int128 must not be assignable from absl::int128"); + + static_assert(std::is_constructible<absl::int128, unsigned __int128>::value, + "absl::int128 must be constructible from unsigned __int128"); + static_assert(!std::is_assignable<absl::int128&, unsigned __int128>::value, + "absl::int128 must be assignable from unsigned __int128"); + static_assert(!std::is_assignable<unsigned __int128&, absl::int128>::value, + "unsigned __int128 must not be assignable from absl::int128"); +} +#endif // ABSL_HAVE_INTRINSIC_INT128 + +TEST(Int128, TrivialTraitsTest) { + static_assert(absl::is_trivially_default_constructible<absl::int128>::value, + ""); + static_assert(absl::is_trivially_copy_constructible<absl::int128>::value, ""); + static_assert(absl::is_trivially_copy_assignable<absl::int128>::value, ""); + static_assert(std::is_trivially_destructible<absl::int128>::value, ""); +} + +TEST(Int128, BoolConversionTest) { + EXPECT_FALSE(absl::int128(0)); + for (int i = 0; i < 64; ++i) { + EXPECT_TRUE(absl::MakeInt128(0, uint64_t{1} << i)); + } + for (int i = 0; i < 63; ++i) { + EXPECT_TRUE(absl::MakeInt128(int64_t{1} << i, 0)); + } + EXPECT_TRUE(absl::Int128Min()); + + EXPECT_EQ(absl::int128(1), absl::int128(true)); + EXPECT_EQ(absl::int128(0), absl::int128(false)); +} + +template <typename T> +class Int128IntegerConversionTest : public ::testing::Test {}; + +TYPED_TEST_SUITE(Int128IntegerConversionTest, IntegerTypes); + +TYPED_TEST(Int128IntegerConversionTest, RoundTripTest) { + EXPECT_EQ(TypeParam{0}, static_cast<TypeParam>(absl::int128(0))); + EXPECT_EQ(std::numeric_limits<TypeParam>::min(), + static_cast<TypeParam>( + absl::int128(std::numeric_limits<TypeParam>::min()))); + EXPECT_EQ(std::numeric_limits<TypeParam>::max(), + static_cast<TypeParam>( + absl::int128(std::numeric_limits<TypeParam>::max()))); +} + +template <typename T> +class Int128FloatConversionTest : public ::testing::Test {}; + +TYPED_TEST_SUITE(Int128FloatConversionTest, FloatingPointTypes); + +TYPED_TEST(Int128FloatConversionTest, ConstructAndCastTest) { + // Conversions where the floating point values should be exactly the same. + // 0x9f5b is a randomly chosen small value. + for (int i = 0; i < 110; ++i) { // 110 = 126 - #bits in 0x9f5b + SCOPED_TRACE(::testing::Message() << "i = " << i); + + TypeParam float_value = std::ldexp(static_cast<TypeParam>(0x9f5b), i); + absl::int128 int_value = absl::int128(0x9f5b) << i; + + EXPECT_EQ(float_value, static_cast<TypeParam>(int_value)); + EXPECT_EQ(-float_value, static_cast<TypeParam>(-int_value)); + EXPECT_EQ(int_value, absl::int128(float_value)); + EXPECT_EQ(-int_value, absl::int128(-float_value)); + } + + // Round trip conversions with a small sample of randomly generated uint64_t + // values (less than int64_t max so that value * 2^64 fits into int128). + uint64_t values[] = {0x6d4492c24fb86199, 0x26ead65e4cb359b5, + 0x2c43407433ba3fd1, 0x3b574ec668df6b55, + 0x1c750e55a29f4f0f}; + for (uint64_t value : values) { + for (int i = 0; i <= 64; ++i) { + SCOPED_TRACE(::testing::Message() + << "value = " << value << "; i = " << i); + + TypeParam fvalue = std::ldexp(static_cast<TypeParam>(value), i); + EXPECT_DOUBLE_EQ(fvalue, static_cast<TypeParam>(absl::int128(fvalue))); + EXPECT_DOUBLE_EQ(-fvalue, static_cast<TypeParam>(-absl::int128(fvalue))); + EXPECT_DOUBLE_EQ(-fvalue, static_cast<TypeParam>(absl::int128(-fvalue))); + EXPECT_DOUBLE_EQ(fvalue, static_cast<TypeParam>(-absl::int128(-fvalue))); + } + } + + // Round trip conversions with a small sample of random large positive values. + absl::int128 large_values[] = { + absl::MakeInt128(0x5b0640d96c7b3d9f, 0xb7a7189e51d18622), + absl::MakeInt128(0x34bed042c6f65270, 0x73b236570669a089), + absl::MakeInt128(0x43deba9e6da12724, 0xf7f0f83da686797d), + absl::MakeInt128(0x71e8d383be4e5589, 0x75c3f96fb00752b6)}; + for (absl::int128 value : large_values) { + // Make value have as many significant bits as can be represented by + // the mantissa, also making sure the highest and lowest bit in the range + // are set. + value >>= (127 - std::numeric_limits<TypeParam>::digits); + value |= absl::int128(1) << (std::numeric_limits<TypeParam>::digits - 1); + value |= 1; + for (int i = 0; i < 127 - std::numeric_limits<TypeParam>::digits; ++i) { + absl::int128 int_value = value << i; + EXPECT_EQ(int_value, + static_cast<absl::int128>(static_cast<TypeParam>(int_value))); + EXPECT_EQ(-int_value, + static_cast<absl::int128>(static_cast<TypeParam>(-int_value))); + } + } + + // Small sample of checks that rounding is toward zero + EXPECT_EQ(0, absl::int128(TypeParam(0.1))); + EXPECT_EQ(17, absl::int128(TypeParam(17.8))); + EXPECT_EQ(0, absl::int128(TypeParam(-0.8))); + EXPECT_EQ(-53, absl::int128(TypeParam(-53.1))); + EXPECT_EQ(0, absl::int128(TypeParam(0.5))); + EXPECT_EQ(0, absl::int128(TypeParam(-0.5))); + TypeParam just_lt_one = std::nexttoward(TypeParam(1), TypeParam(0)); + EXPECT_EQ(0, absl::int128(just_lt_one)); + TypeParam just_gt_minus_one = std::nexttoward(TypeParam(-1), TypeParam(0)); + EXPECT_EQ(0, absl::int128(just_gt_minus_one)); + + // Check limits + EXPECT_DOUBLE_EQ(std::ldexp(static_cast<TypeParam>(1), 127), + static_cast<TypeParam>(absl::Int128Max())); + EXPECT_DOUBLE_EQ(-std::ldexp(static_cast<TypeParam>(1), 127), + static_cast<TypeParam>(absl::Int128Min())); +} + +TEST(Int128, FactoryTest) { + EXPECT_EQ(absl::int128(-1), absl::MakeInt128(-1, -1)); + EXPECT_EQ(absl::int128(-31), absl::MakeInt128(-1, -31)); + EXPECT_EQ(absl::int128(std::numeric_limits<int64_t>::min()), + absl::MakeInt128(-1, std::numeric_limits<int64_t>::min())); + EXPECT_EQ(absl::int128(0), absl::MakeInt128(0, 0)); + EXPECT_EQ(absl::int128(1), absl::MakeInt128(0, 1)); + EXPECT_EQ(absl::int128(std::numeric_limits<int64_t>::max()), + absl::MakeInt128(0, std::numeric_limits<int64_t>::max())); +} + +TEST(Int128, HighLowTest) { + struct HighLowPair { + int64_t high; + uint64_t low; + }; + HighLowPair values[]{{0, 0}, {0, 1}, {1, 0}, {123, 456}, {-654, 321}}; + for (const HighLowPair& pair : values) { + absl::int128 value = absl::MakeInt128(pair.high, pair.low); + EXPECT_EQ(pair.low, absl::Int128Low64(value)); + EXPECT_EQ(pair.high, absl::Int128High64(value)); + } +} + +TEST(Int128, LimitsTest) { + EXPECT_EQ(absl::MakeInt128(0x7fffffffffffffff, 0xffffffffffffffff), + absl::Int128Max()); + EXPECT_EQ(absl::Int128Max(), ~absl::Int128Min()); +} + +#if defined(ABSL_HAVE_INTRINSIC_INT128) +TEST(Int128, IntrinsicConversionTest) { + __int128 intrinsic = + (static_cast<__int128>(0x3a5b76c209de76f6) << 64) + 0x1f25e1d63a2b46c5; + absl::int128 custom = + absl::MakeInt128(0x3a5b76c209de76f6, 0x1f25e1d63a2b46c5); + + EXPECT_EQ(custom, absl::int128(intrinsic)); + EXPECT_EQ(intrinsic, static_cast<__int128>(custom)); +} +#endif // ABSL_HAVE_INTRINSIC_INT128 + +TEST(Int128, ConstexprTest) { + constexpr absl::int128 zero = absl::int128(); + constexpr absl::int128 one = 1; + constexpr absl::int128 minus_two = -2; + constexpr absl::int128 min = absl::Int128Min(); + constexpr absl::int128 max = absl::Int128Max(); + EXPECT_EQ(zero, absl::int128(0)); + EXPECT_EQ(one, absl::int128(1)); + EXPECT_EQ(minus_two, absl::MakeInt128(-1, -2)); + EXPECT_GT(max, one); + EXPECT_LT(min, minus_two); +} + +TEST(Int128, ComparisonTest) { + struct TestCase { + absl::int128 smaller; + absl::int128 larger; + }; + TestCase cases[] = { + {absl::int128(0), absl::int128(123)}, + {absl::MakeInt128(-12, 34), absl::MakeInt128(12, 34)}, + {absl::MakeInt128(1, 1000), absl::MakeInt128(1000, 1)}, + {absl::MakeInt128(-1000, 1000), absl::MakeInt128(-1, 1)}, + }; + for (const TestCase& pair : cases) { + SCOPED_TRACE(::testing::Message() << "pair.smaller = " << pair.smaller + << "; pair.larger = " << pair.larger); + + EXPECT_TRUE(pair.smaller == pair.smaller); // NOLINT(readability/check) + EXPECT_TRUE(pair.larger == pair.larger); // NOLINT(readability/check) + EXPECT_FALSE(pair.smaller == pair.larger); // NOLINT(readability/check) + + EXPECT_TRUE(pair.smaller != pair.larger); // NOLINT(readability/check) + EXPECT_FALSE(pair.smaller != pair.smaller); // NOLINT(readability/check) + EXPECT_FALSE(pair.larger != pair.larger); // NOLINT(readability/check) + + EXPECT_TRUE(pair.smaller < pair.larger); // NOLINT(readability/check) + EXPECT_FALSE(pair.larger < pair.smaller); // NOLINT(readability/check) + + EXPECT_TRUE(pair.larger > pair.smaller); // NOLINT(readability/check) + EXPECT_FALSE(pair.smaller > pair.larger); // NOLINT(readability/check) + + EXPECT_TRUE(pair.smaller <= pair.larger); // NOLINT(readability/check) + EXPECT_FALSE(pair.larger <= pair.smaller); // NOLINT(readability/check) + EXPECT_TRUE(pair.smaller <= pair.smaller); // NOLINT(readability/check) + EXPECT_TRUE(pair.larger <= pair.larger); // NOLINT(readability/check) + + EXPECT_TRUE(pair.larger >= pair.smaller); // NOLINT(readability/check) + EXPECT_FALSE(pair.smaller >= pair.larger); // NOLINT(readability/check) + EXPECT_TRUE(pair.smaller >= pair.smaller); // NOLINT(readability/check) + EXPECT_TRUE(pair.larger >= pair.larger); // NOLINT(readability/check) + } +} + +TEST(Int128, UnaryNegationTest) { + int64_t values64[] = {0, 1, 12345, 0x4000000000000000, + std::numeric_limits<int64_t>::max()}; + for (int64_t value : values64) { + SCOPED_TRACE(::testing::Message() << "value = " << value); + + EXPECT_EQ(absl::int128(-value), -absl::int128(value)); + EXPECT_EQ(absl::int128(value), -absl::int128(-value)); + EXPECT_EQ(absl::MakeInt128(-value, 0), -absl::MakeInt128(value, 0)); + EXPECT_EQ(absl::MakeInt128(value, 0), -absl::MakeInt128(-value, 0)); + } +} + +TEST(Int128, LogicalNotTest) { + EXPECT_TRUE(!absl::int128(0)); + for (int i = 0; i < 64; ++i) { + EXPECT_FALSE(!absl::MakeInt128(0, uint64_t{1} << i)); + } + for (int i = 0; i < 63; ++i) { + EXPECT_FALSE(!absl::MakeInt128(int64_t{1} << i, 0)); + } +} + +TEST(Int128, AdditionSubtractionTest) { + // 64 bit pairs that will not cause overflow / underflow. These test negative + // carry; positive carry must be checked separately. + std::pair<int64_t, int64_t> cases[]{ + {0, 0}, // 0, 0 + {0, 2945781290834}, // 0, + + {1908357619234, 0}, // +, 0 + {0, -1204895918245}, // 0, - + {-2957928523560, 0}, // -, 0 + {89023982312461, 98346012567134}, // +, + + {-63454234568239, -23456235230773}, // -, - + {98263457263502, -21428561935925}, // +, - + {-88235237438467, 15923659234573}, // -, + + }; + for (const auto& pair : cases) { + SCOPED_TRACE(::testing::Message() + << "pair = {" << pair.first << ", " << pair.second << '}'); + + EXPECT_EQ(absl::int128(pair.first + pair.second), + absl::int128(pair.first) + absl::int128(pair.second)); + EXPECT_EQ(absl::int128(pair.second + pair.first), + absl::int128(pair.second) += absl::int128(pair.first)); + + EXPECT_EQ(absl::int128(pair.first - pair.second), + absl::int128(pair.first) - absl::int128(pair.second)); + EXPECT_EQ(absl::int128(pair.second - pair.first), + absl::int128(pair.second) -= absl::int128(pair.first)); + + EXPECT_EQ( + absl::MakeInt128(pair.second + pair.first, 0), + absl::MakeInt128(pair.second, 0) + absl::MakeInt128(pair.first, 0)); + EXPECT_EQ( + absl::MakeInt128(pair.first + pair.second, 0), + absl::MakeInt128(pair.first, 0) += absl::MakeInt128(pair.second, 0)); + + EXPECT_EQ( + absl::MakeInt128(pair.second - pair.first, 0), + absl::MakeInt128(pair.second, 0) - absl::MakeInt128(pair.first, 0)); + EXPECT_EQ( + absl::MakeInt128(pair.first - pair.second, 0), + absl::MakeInt128(pair.first, 0) -= absl::MakeInt128(pair.second, 0)); + } + + // check positive carry + EXPECT_EQ(absl::MakeInt128(31, 0), + absl::MakeInt128(20, 1) + + absl::MakeInt128(10, std::numeric_limits<uint64_t>::max())); +} + +TEST(Int128, IncrementDecrementTest) { + absl::int128 value = 0; + EXPECT_EQ(0, value++); + EXPECT_EQ(1, value); + EXPECT_EQ(1, value--); + EXPECT_EQ(0, value); + EXPECT_EQ(-1, --value); + EXPECT_EQ(-1, value); + EXPECT_EQ(0, ++value); + EXPECT_EQ(0, value); +} + +TEST(Int128, MultiplicationTest) { + // 1 bit x 1 bit, and negative combinations + for (int i = 0; i < 64; ++i) { + for (int j = 0; j < 127 - i; ++j) { + SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j); + absl::int128 a = absl::int128(1) << i; + absl::int128 b = absl::int128(1) << j; + absl::int128 c = absl::int128(1) << (i + j); + + EXPECT_EQ(c, a * b); + EXPECT_EQ(-c, -a * b); + EXPECT_EQ(-c, a * -b); + EXPECT_EQ(c, -a * -b); + + EXPECT_EQ(c, absl::int128(a) *= b); + EXPECT_EQ(-c, absl::int128(-a) *= b); + EXPECT_EQ(-c, absl::int128(a) *= -b); + EXPECT_EQ(c, absl::int128(-a) *= -b); + } + } + + // Pairs of random values that will not overflow signed 64-bit multiplication + std::pair<int64_t, int64_t> small_values[] = { + {0x5e61, 0xf29f79ca14b4}, // +, + + {0x3e033b, -0x612c0ee549}, // +, - + {-0x052ce7e8, 0x7c728f0f}, // -, + + {-0x3af7054626, -0xfb1e1d}, // -, - + }; + for (const std::pair<int64_t, int64_t>& pair : small_values) { + SCOPED_TRACE(::testing::Message() + << "pair = {" << pair.first << ", " << pair.second << '}'); + + EXPECT_EQ(absl::int128(pair.first * pair.second), + absl::int128(pair.first) * absl::int128(pair.second)); + EXPECT_EQ(absl::int128(pair.first * pair.second), + absl::int128(pair.first) *= absl::int128(pair.second)); + + EXPECT_EQ(absl::MakeInt128(pair.first * pair.second, 0), + absl::MakeInt128(pair.first, 0) * absl::int128(pair.second)); + EXPECT_EQ(absl::MakeInt128(pair.first * pair.second, 0), + absl::MakeInt128(pair.first, 0) *= absl::int128(pair.second)); + } + + // Pairs of positive random values that will not overflow 64-bit + // multiplication and can be left shifted by 32 without overflow + std::pair<int64_t, int64_t> small_values2[] = { + {0x1bb0a110, 0x31487671}, + {0x4792784e, 0x28add7d7}, + {0x7b66553a, 0x11dff8ef}, + }; + for (const std::pair<int64_t, int64_t>& pair : small_values2) { + SCOPED_TRACE(::testing::Message() + << "pair = {" << pair.first << ", " << pair.second << '}'); + + absl::int128 a = absl::int128(pair.first << 32); + absl::int128 b = absl::int128(pair.second << 32); + absl::int128 c = absl::MakeInt128(pair.first * pair.second, 0); + + EXPECT_EQ(c, a * b); + EXPECT_EQ(-c, -a * b); + EXPECT_EQ(-c, a * -b); + EXPECT_EQ(c, -a * -b); + + EXPECT_EQ(c, absl::int128(a) *= b); + EXPECT_EQ(-c, absl::int128(-a) *= b); + EXPECT_EQ(-c, absl::int128(a) *= -b); + EXPECT_EQ(c, absl::int128(-a) *= -b); + } + + // check 0, 1, and -1 behavior with large values + absl::int128 large_values[] = { + {absl::MakeInt128(0xd66f061af02d0408, 0x727d2846cb475b53)}, + {absl::MakeInt128(0x27b8d5ed6104452d, 0x03f8a33b0ee1df4f)}, + {-absl::MakeInt128(0x621b6626b9e8d042, 0x27311ac99df00938)}, + {-absl::MakeInt128(0x34e0656f1e95fb60, 0x4281cfd731257a47)}, + }; + for (absl::int128 value : large_values) { + EXPECT_EQ(0, 0 * value); + EXPECT_EQ(0, value * 0); + EXPECT_EQ(0, absl::int128(0) *= value); + EXPECT_EQ(0, value *= 0); + + EXPECT_EQ(value, 1 * value); + EXPECT_EQ(value, value * 1); + EXPECT_EQ(value, absl::int128(1) *= value); + EXPECT_EQ(value, value *= 1); + + EXPECT_EQ(-value, -1 * value); + EXPECT_EQ(-value, value * -1); + EXPECT_EQ(-value, absl::int128(-1) *= value); + EXPECT_EQ(-value, value *= -1); + } + + // Manually calculated random large value cases + EXPECT_EQ(absl::MakeInt128(0xcd0efd3442219bb, 0xde47c05bcd9df6e1), + absl::MakeInt128(0x7c6448, 0x3bc4285c47a9d253) * 0x1a6037537b); + EXPECT_EQ(-absl::MakeInt128(0x1f8f149850b1e5e6, 0x1e50d6b52d272c3e), + -absl::MakeInt128(0x23, 0x2e68a513ca1b8859) * 0xe5a434cd14866e); + EXPECT_EQ(-absl::MakeInt128(0x55cae732029d1fce, 0xca6474b6423263e4), + 0xa9b98a8ddf66bc * -absl::MakeInt128(0x81, 0x672e58231e2469d7)); + EXPECT_EQ(absl::MakeInt128(0x19c8b7620b507dc4, 0xfec042b71a5f29a4), + -0x3e39341147 * -absl::MakeInt128(0x6a14b2, 0x5ed34cca42327b3c)); + + EXPECT_EQ(absl::MakeInt128(0xcd0efd3442219bb, 0xde47c05bcd9df6e1), + absl::MakeInt128(0x7c6448, 0x3bc4285c47a9d253) *= 0x1a6037537b); + EXPECT_EQ(-absl::MakeInt128(0x1f8f149850b1e5e6, 0x1e50d6b52d272c3e), + -absl::MakeInt128(0x23, 0x2e68a513ca1b8859) *= 0xe5a434cd14866e); + EXPECT_EQ(-absl::MakeInt128(0x55cae732029d1fce, 0xca6474b6423263e4), + absl::int128(0xa9b98a8ddf66bc) *= + -absl::MakeInt128(0x81, 0x672e58231e2469d7)); + EXPECT_EQ(absl::MakeInt128(0x19c8b7620b507dc4, 0xfec042b71a5f29a4), + absl::int128(-0x3e39341147) *= + -absl::MakeInt128(0x6a14b2, 0x5ed34cca42327b3c)); +} + +TEST(Int128, DivisionAndModuloTest) { + // Check against 64 bit division and modulo operators with a sample of + // randomly generated pairs. + std::pair<int64_t, int64_t> small_pairs[] = { + {0x15f2a64138, 0x67da05}, {0x5e56d194af43045f, 0xcf1543fb99}, + {0x15e61ed052036a, -0xc8e6}, {0x88125a341e85, -0xd23fb77683}, + {-0xc06e20, 0x5a}, {-0x4f100219aea3e85d, 0xdcc56cb4efe993}, + {-0x168d629105, -0xa7}, {-0x7b44e92f03ab2375, -0x6516}, + }; + for (const std::pair<int64_t, int64_t>& pair : small_pairs) { + SCOPED_TRACE(::testing::Message() + << "pair = {" << pair.first << ", " << pair.second << '}'); + + absl::int128 dividend = pair.first; + absl::int128 divisor = pair.second; + int64_t quotient = pair.first / pair.second; + int64_t remainder = pair.first % pair.second; + + EXPECT_EQ(quotient, dividend / divisor); + EXPECT_EQ(quotient, absl::int128(dividend) /= divisor); + EXPECT_EQ(remainder, dividend % divisor); + EXPECT_EQ(remainder, absl::int128(dividend) %= divisor); + } + + // Test behavior with 0, 1, and -1 with a sample of randomly generated large + // values. + absl::int128 values[] = { + absl::MakeInt128(0x63d26ee688a962b2, 0x9e1411abda5c1d70), + absl::MakeInt128(0x152f385159d6f986, 0xbf8d48ef63da395d), + -absl::MakeInt128(0x3098d7567030038c, 0x14e7a8a098dc2164), + -absl::MakeInt128(0x49a037aca35c809f, 0xa6a87525480ef330), + }; + for (absl::int128 value : values) { + SCOPED_TRACE(::testing::Message() << "value = " << value); + + EXPECT_EQ(0, 0 / value); + EXPECT_EQ(0, absl::int128(0) /= value); + EXPECT_EQ(0, 0 % value); + EXPECT_EQ(0, absl::int128(0) %= value); + + EXPECT_EQ(value, value / 1); + EXPECT_EQ(value, absl::int128(value) /= 1); + EXPECT_EQ(0, value % 1); + EXPECT_EQ(0, absl::int128(value) %= 1); + + EXPECT_EQ(-value, value / -1); + EXPECT_EQ(-value, absl::int128(value) /= -1); + EXPECT_EQ(0, value % -1); + EXPECT_EQ(0, absl::int128(value) %= -1); + } + + // Min and max values + EXPECT_EQ(0, absl::Int128Max() / absl::Int128Min()); + EXPECT_EQ(absl::Int128Max(), absl::Int128Max() % absl::Int128Min()); + EXPECT_EQ(-1, absl::Int128Min() / absl::Int128Max()); + EXPECT_EQ(-1, absl::Int128Min() % absl::Int128Max()); + + // Power of two division and modulo of random large dividends + absl::int128 positive_values[] = { + absl::MakeInt128(0x21e1a1cc69574620, 0xe7ac447fab2fc869), + absl::MakeInt128(0x32c2ff3ab89e66e8, 0x03379a613fd1ce74), + absl::MakeInt128(0x6f32ca786184dcaf, 0x046f9c9ecb3a9ce1), + absl::MakeInt128(0x1aeb469dd990e0ee, 0xda2740f243cd37eb), + }; + for (absl::int128 value : positive_values) { + for (int i = 0; i < 127; ++i) { + SCOPED_TRACE(::testing::Message() + << "value = " << value << "; i = " << i); + absl::int128 power_of_two = absl::int128(1) << i; + + EXPECT_EQ(value >> i, value / power_of_two); + EXPECT_EQ(value >> i, absl::int128(value) /= power_of_two); + EXPECT_EQ(value & (power_of_two - 1), value % power_of_two); + EXPECT_EQ(value & (power_of_two - 1), + absl::int128(value) %= power_of_two); + } + } + + // Manually calculated cases with random large dividends + struct DivisionModCase { + absl::int128 dividend; + absl::int128 divisor; + absl::int128 quotient; + absl::int128 remainder; + }; + DivisionModCase manual_cases[] = { + {absl::MakeInt128(0x6ada48d489007966, 0x3c9c5c98150d5d69), + absl::MakeInt128(0x8bc308fb, 0x8cb9cc9a3b803344), 0xc3b87e08, + absl::MakeInt128(0x1b7db5e1, 0xd9eca34b7af04b49)}, + {absl::MakeInt128(0xd6946511b5b, 0x4886c5c96546bf5f), + -absl::MakeInt128(0x263b, 0xfd516279efcfe2dc), -0x59cbabf0, + absl::MakeInt128(0x622, 0xf462909155651d1f)}, + {-absl::MakeInt128(0x33db734f9e8d1399, 0x8447ac92482bca4d), 0x37495078240, + -absl::MakeInt128(0xf01f1, 0xbc0368bf9a77eae8), -0x21a508f404d}, + {-absl::MakeInt128(0x13f837b409a07e7d, 0x7fc8e248a7d73560), -0x1b9f, + absl::MakeInt128(0xb9157556d724, 0xb14f635714d7563e), -0x1ade}, + }; + for (const DivisionModCase test_case : manual_cases) { + EXPECT_EQ(test_case.quotient, test_case.dividend / test_case.divisor); + EXPECT_EQ(test_case.quotient, + absl::int128(test_case.dividend) /= test_case.divisor); + EXPECT_EQ(test_case.remainder, test_case.dividend % test_case.divisor); + EXPECT_EQ(test_case.remainder, + absl::int128(test_case.dividend) %= test_case.divisor); + } +} + +TEST(Int128, BitwiseLogicTest) { + EXPECT_EQ(absl::int128(-1), ~absl::int128(0)); + + absl::int128 values[]{ + 0, -1, 0xde400bee05c3ff6b, absl::MakeInt128(0x7f32178dd81d634a, 0), + absl::MakeInt128(0xaf539057055613a9, 0x7d104d7d946c2e4d)}; + for (absl::int128 value : values) { + EXPECT_EQ(value, ~~value); + + EXPECT_EQ(value, value | value); + EXPECT_EQ(value, value & value); + EXPECT_EQ(0, value ^ value); + + EXPECT_EQ(value, absl::int128(value) |= value); + EXPECT_EQ(value, absl::int128(value) &= value); + EXPECT_EQ(0, absl::int128(value) ^= value); + + EXPECT_EQ(value, value | 0); + EXPECT_EQ(0, value & 0); + EXPECT_EQ(value, value ^ 0); + + EXPECT_EQ(absl::int128(-1), value | absl::int128(-1)); + EXPECT_EQ(value, value & absl::int128(-1)); + EXPECT_EQ(~value, value ^ absl::int128(-1)); + } + + // small sample of randomly generated int64_t's + std::pair<int64_t, int64_t> pairs64[]{ + {0x7f86797f5e991af4, 0x1ee30494fb007c97}, + {0x0b278282bacf01af, 0x58780e0a57a49e86}, + {0x059f266ccb93a666, 0x3d5b731bae9286f5}, + {0x63c0c4820f12108c, 0x58166713c12e1c3a}, + {0x381488bb2ed2a66e, 0x2220a3eb76a3698c}, + {0x2a0a0dfb81e06f21, 0x4b60585927f5523c}, + {0x555b1c3a03698537, 0x25478cd19d8e53cb}, + {0x4750f6f27d779225, 0x16397553c6ff05fc}, + }; + for (const std::pair<int64_t, int64_t>& pair : pairs64) { + SCOPED_TRACE(::testing::Message() + << "pair = {" << pair.first << ", " << pair.second << '}'); + + EXPECT_EQ(absl::MakeInt128(~pair.first, ~pair.second), + ~absl::MakeInt128(pair.first, pair.second)); + + EXPECT_EQ(absl::int128(pair.first & pair.second), + absl::int128(pair.first) & absl::int128(pair.second)); + EXPECT_EQ(absl::int128(pair.first | pair.second), + absl::int128(pair.first) | absl::int128(pair.second)); + EXPECT_EQ(absl::int128(pair.first ^ pair.second), + absl::int128(pair.first) ^ absl::int128(pair.second)); + + EXPECT_EQ(absl::int128(pair.first & pair.second), + absl::int128(pair.first) &= absl::int128(pair.second)); + EXPECT_EQ(absl::int128(pair.first | pair.second), + absl::int128(pair.first) |= absl::int128(pair.second)); + EXPECT_EQ(absl::int128(pair.first ^ pair.second), + absl::int128(pair.first) ^= absl::int128(pair.second)); + + EXPECT_EQ( + absl::MakeInt128(pair.first & pair.second, 0), + absl::MakeInt128(pair.first, 0) & absl::MakeInt128(pair.second, 0)); + EXPECT_EQ( + absl::MakeInt128(pair.first | pair.second, 0), + absl::MakeInt128(pair.first, 0) | absl::MakeInt128(pair.second, 0)); + EXPECT_EQ( + absl::MakeInt128(pair.first ^ pair.second, 0), + absl::MakeInt128(pair.first, 0) ^ absl::MakeInt128(pair.second, 0)); + + EXPECT_EQ( + absl::MakeInt128(pair.first & pair.second, 0), + absl::MakeInt128(pair.first, 0) &= absl::MakeInt128(pair.second, 0)); + EXPECT_EQ( + absl::MakeInt128(pair.first | pair.second, 0), + absl::MakeInt128(pair.first, 0) |= absl::MakeInt128(pair.second, 0)); + EXPECT_EQ( + absl::MakeInt128(pair.first ^ pair.second, 0), + absl::MakeInt128(pair.first, 0) ^= absl::MakeInt128(pair.second, 0)); + } +} + +TEST(Int128, BitwiseShiftTest) { + for (int i = 0; i < 64; ++i) { + for (int j = 0; j <= i; ++j) { + // Left shift from j-th bit to i-th bit. + SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j); + EXPECT_EQ(uint64_t{1} << i, absl::int128(uint64_t{1} << j) << (i - j)); + EXPECT_EQ(uint64_t{1} << i, absl::int128(uint64_t{1} << j) <<= (i - j)); + } + } + for (int i = 0; i < 63; ++i) { + for (int j = 0; j < 64; ++j) { + // Left shift from j-th bit to (i + 64)-th bit. + SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j); + EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0), + absl::int128(uint64_t{1} << j) << (i + 64 - j)); + EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0), + absl::int128(uint64_t{1} << j) <<= (i + 64 - j)); + } + for (int j = 0; j <= i; ++j) { + // Left shift from (j + 64)-th bit to (i + 64)-th bit. + SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j); + EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0), + absl::MakeInt128(uint64_t{1} << j, 0) << (i - j)); + EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0), + absl::MakeInt128(uint64_t{1} << j, 0) <<= (i - j)); + } + } + + for (int i = 0; i < 64; ++i) { + for (int j = i; j < 64; ++j) { + // Right shift from j-th bit to i-th bit. + SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j); + EXPECT_EQ(uint64_t{1} << i, absl::int128(uint64_t{1} << j) >> (j - i)); + EXPECT_EQ(uint64_t{1} << i, absl::int128(uint64_t{1} << j) >>= (j - i)); + } + for (int j = 0; j < 63; ++j) { + // Right shift from (j + 64)-th bit to i-th bit. + SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j); + EXPECT_EQ(uint64_t{1} << i, + absl::MakeInt128(uint64_t{1} << j, 0) >> (j + 64 - i)); + EXPECT_EQ(uint64_t{1} << i, + absl::MakeInt128(uint64_t{1} << j, 0) >>= (j + 64 - i)); + } + } + for (int i = 0; i < 63; ++i) { + for (int j = i; j < 63; ++j) { + // Right shift from (j + 64)-th bit to (i + 64)-th bit. + SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j); + EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0), + absl::MakeInt128(uint64_t{1} << j, 0) >> (j - i)); + EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0), + absl::MakeInt128(uint64_t{1} << j, 0) >>= (j - i)); + } + } +} + +TEST(Int128, NumericLimitsTest) { + static_assert(std::numeric_limits<absl::int128>::is_specialized, ""); + static_assert(std::numeric_limits<absl::int128>::is_signed, ""); + static_assert(std::numeric_limits<absl::int128>::is_integer, ""); + EXPECT_EQ(static_cast<int>(127 * std::log10(2)), + std::numeric_limits<absl::int128>::digits10); + EXPECT_EQ(absl::Int128Min(), std::numeric_limits<absl::int128>::min()); + EXPECT_EQ(absl::Int128Min(), std::numeric_limits<absl::int128>::lowest()); + EXPECT_EQ(absl::Int128Max(), std::numeric_limits<absl::int128>::max()); +} + } // namespace |