1// 2// Copyright 2017 The Abseil Authors. 3// 4// Licensed under the Apache License, Version 2.0 (the "License"); 5// you may not use this file except in compliance with the License. 6// You may obtain a copy of the License at 7// 8// https://www.apache.org/licenses/LICENSE-2.0 9// 10// Unless required by applicable law or agreed to in writing, software 11// distributed under the License is distributed on an "AS IS" BASIS, 12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13// See the License for the specific language governing permissions and 14// limitations under the License. 15 16// This file contains :int128 implementation details that depend on internal 17// representation when ABSL_HAVE_INTRINSIC_INT128 is defined. This file is 18// included by int128.h and relies on ABSL_INTERNAL_WCHAR_T being defined. 19 20namespace int128_internal { 21 22// Casts from unsigned to signed while preserving the underlying binary 23// representation. 24constexpr __int128 BitCastToSigned(unsigned __int128 v) { 25 // Casting an unsigned integer to a signed integer of the same 26 // width is implementation defined behavior if the source value would not fit 27 // in the destination type. We step around it with a roundtrip bitwise not 28 // operation to make sure this function remains constexpr. Clang and GCC 29 // optimize this to a no-op on x86-64. 30 return v & (static_cast<unsigned __int128>(1) << 127) 31 ? ~static_cast<__int128>(~v) 32 : static_cast<__int128>(v); 33} 34 35} // namespace int128_internal 36 37inline int128& int128::operator=(__int128 v) { 38 v_ = v; 39 return *this; 40} 41 42constexpr uint64_t Int128Low64(int128 v) { 43 return static_cast<uint64_t>(v.v_ & ~uint64_t{0}); 44} 45 46constexpr int64_t Int128High64(int128 v) { 47 // Initially cast to unsigned to prevent a right shift on a negative value. 48 return int128_internal::BitCastToSigned( 49 static_cast<uint64_t>(static_cast<unsigned __int128>(v.v_) >> 64)); 50} 51 52constexpr int128::int128(int64_t high, uint64_t low) 53 // Initially cast to unsigned to prevent a left shift that overflows. 54 : v_(int128_internal::BitCastToSigned(static_cast<unsigned __int128>(high) 55 << 64) | 56 low) {} 57 58 59constexpr int128::int128(int v) : v_{v} {} 60 61constexpr int128::int128(long v) : v_{v} {} // NOLINT(runtime/int) 62 63constexpr int128::int128(long long v) : v_{v} {} // NOLINT(runtime/int) 64 65constexpr int128::int128(__int128 v) : v_{v} {} 66 67constexpr int128::int128(unsigned int v) : v_{v} {} 68 69constexpr int128::int128(unsigned long v) : v_{v} {} // NOLINT(runtime/int) 70 71// NOLINTNEXTLINE(runtime/int) 72constexpr int128::int128(unsigned long long v) : v_{v} {} 73 74constexpr int128::int128(unsigned __int128 v) : v_{static_cast<__int128>(v)} {} 75 76inline int128::int128(float v) { 77 v_ = static_cast<__int128>(v); 78} 79 80inline int128::int128(double v) { 81 v_ = static_cast<__int128>(v); 82} 83 84inline int128::int128(long double v) { 85 v_ = static_cast<__int128>(v); 86} 87 88constexpr int128::int128(uint128 v) : v_{static_cast<__int128>(v)} {} 89 90constexpr int128::operator bool() const { return static_cast<bool>(v_); } 91 92constexpr int128::operator char() const { return static_cast<char>(v_); } 93 94constexpr int128::operator signed char() const { 95 return static_cast<signed char>(v_); 96} 97 98constexpr int128::operator unsigned char() const { 99 return static_cast<unsigned char>(v_); 100} 101 102constexpr int128::operator char16_t() const { 103 return static_cast<char16_t>(v_); 104} 105 106constexpr int128::operator char32_t() const { 107 return static_cast<char32_t>(v_); 108} 109 110constexpr int128::operator ABSL_INTERNAL_WCHAR_T() const { 111 return static_cast<ABSL_INTERNAL_WCHAR_T>(v_); 112} 113 114constexpr int128::operator short() const { // NOLINT(runtime/int) 115 return static_cast<short>(v_); // NOLINT(runtime/int) 116} 117 118constexpr int128::operator unsigned short() const { // NOLINT(runtime/int) 119 return static_cast<unsigned short>(v_); // NOLINT(runtime/int) 120} 121 122constexpr int128::operator int() const { 123 return static_cast<int>(v_); 124} 125 126constexpr int128::operator unsigned int() const { 127 return static_cast<unsigned int>(v_); 128} 129 130constexpr int128::operator long() const { // NOLINT(runtime/int) 131 return static_cast<long>(v_); // NOLINT(runtime/int) 132} 133 134constexpr int128::operator unsigned long() const { // NOLINT(runtime/int) 135 return static_cast<unsigned long>(v_); // NOLINT(runtime/int) 136} 137 138constexpr int128::operator long long() const { // NOLINT(runtime/int) 139 return static_cast<long long>(v_); // NOLINT(runtime/int) 140} 141 142constexpr int128::operator unsigned long long() const { // NOLINT(runtime/int) 143 return static_cast<unsigned long long>(v_); // NOLINT(runtime/int) 144} 145 146constexpr int128::operator __int128() const { return v_; } 147 148constexpr int128::operator unsigned __int128() const { 149 return static_cast<unsigned __int128>(v_); 150} 151 152// Clang on PowerPC sometimes produces incorrect __int128 to floating point 153// conversions. In that case, we do the conversion with a similar implementation 154// to the conversion operators in int128_no_intrinsic.inc. 155#if defined(__clang__) && !defined(__ppc64__) 156inline int128::operator float() const { return static_cast<float>(v_); } 157 158inline int128::operator double() const { return static_cast<double>(v_); } 159 160inline int128::operator long double() const { 161 return static_cast<long double>(v_); 162} 163 164#else // Clang on PowerPC 165// Forward declaration for conversion operators to floating point types. 166constexpr int128 operator-(int128 v); 167constexpr bool operator!=(int128 lhs, int128 rhs); 168 169inline int128::operator float() const { 170 // We must convert the absolute value and then negate as needed, because 171 // floating point types are typically sign-magnitude. Otherwise, the 172 // difference between the high and low 64 bits when interpreted as two's 173 // complement overwhelms the precision of the mantissa. 174 // 175 // Also check to make sure we don't negate Int128Min() 176 return v_ < 0 && *this != Int128Min() 177 ? -static_cast<float>(-*this) 178 : static_cast<float>(Int128Low64(*this)) + 179 std::ldexp(static_cast<float>(Int128High64(*this)), 64); 180} 181 182inline int128::operator double() const { 183 // See comment in int128::operator float() above. 184 return v_ < 0 && *this != Int128Min() 185 ? -static_cast<double>(-*this) 186 : static_cast<double>(Int128Low64(*this)) + 187 std::ldexp(static_cast<double>(Int128High64(*this)), 64); 188} 189 190inline int128::operator long double() const { 191 // See comment in int128::operator float() above. 192 return v_ < 0 && *this != Int128Min() 193 ? -static_cast<long double>(-*this) 194 : static_cast<long double>(Int128Low64(*this)) + 195 std::ldexp(static_cast<long double>(Int128High64(*this)), 196 64); 197} 198#endif // Clang on PowerPC 199 200// Comparison operators. 201 202constexpr bool operator==(int128 lhs, int128 rhs) { 203 return static_cast<__int128>(lhs) == static_cast<__int128>(rhs); 204} 205 206constexpr bool operator!=(int128 lhs, int128 rhs) { 207 return static_cast<__int128>(lhs) != static_cast<__int128>(rhs); 208} 209 210constexpr bool operator<(int128 lhs, int128 rhs) { 211 return static_cast<__int128>(lhs) < static_cast<__int128>(rhs); 212} 213 214constexpr bool operator>(int128 lhs, int128 rhs) { 215 return static_cast<__int128>(lhs) > static_cast<__int128>(rhs); 216} 217 218constexpr bool operator<=(int128 lhs, int128 rhs) { 219 return static_cast<__int128>(lhs) <= static_cast<__int128>(rhs); 220} 221 222constexpr bool operator>=(int128 lhs, int128 rhs) { 223 return static_cast<__int128>(lhs) >= static_cast<__int128>(rhs); 224} 225 226// Unary operators. 227 228constexpr int128 operator-(int128 v) { return -static_cast<__int128>(v); } 229 230constexpr bool operator!(int128 v) { return !static_cast<__int128>(v); } 231 232constexpr int128 operator~(int128 val) { return ~static_cast<__int128>(val); } 233 234// Arithmetic operators. 235 236constexpr int128 operator+(int128 lhs, int128 rhs) { 237 return static_cast<__int128>(lhs) + static_cast<__int128>(rhs); 238} 239 240constexpr int128 operator-(int128 lhs, int128 rhs) { 241 return static_cast<__int128>(lhs) - static_cast<__int128>(rhs); 242} 243 244inline int128 operator*(int128 lhs, int128 rhs) { 245 return static_cast<__int128>(lhs) * static_cast<__int128>(rhs); 246} 247 248inline int128 operator/(int128 lhs, int128 rhs) { 249 return static_cast<__int128>(lhs) / static_cast<__int128>(rhs); 250} 251 252inline int128 operator%(int128 lhs, int128 rhs) { 253 return static_cast<__int128>(lhs) % static_cast<__int128>(rhs); 254} 255 256inline int128 int128::operator++(int) { 257 int128 tmp(*this); 258 ++v_; 259 return tmp; 260} 261 262inline int128 int128::operator--(int) { 263 int128 tmp(*this); 264 --v_; 265 return tmp; 266} 267 268inline int128& int128::operator++() { 269 ++v_; 270 return *this; 271} 272 273inline int128& int128::operator--() { 274 --v_; 275 return *this; 276} 277 278constexpr int128 operator|(int128 lhs, int128 rhs) { 279 return static_cast<__int128>(lhs) | static_cast<__int128>(rhs); 280} 281 282constexpr int128 operator&(int128 lhs, int128 rhs) { 283 return static_cast<__int128>(lhs) & static_cast<__int128>(rhs); 284} 285 286constexpr int128 operator^(int128 lhs, int128 rhs) { 287 return static_cast<__int128>(lhs) ^ static_cast<__int128>(rhs); 288} 289 290constexpr int128 operator<<(int128 lhs, int amount) { 291 return static_cast<__int128>(lhs) << amount; 292} 293 294constexpr int128 operator>>(int128 lhs, int amount) { 295 return static_cast<__int128>(lhs) >> amount; 296} 297