int128_have_intrinsic.inc 9.0 KB

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  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. // This file contains :int128 implementation details that depend on internal
  16. // representation when Y_ABSL_HAVE_INTRINSIC_INT128 is defined. This file is
  17. // included by int128.h and relies on Y_ABSL_INTERNAL_WCHAR_T being defined.
  18. namespace int128_internal {
  19. // Casts from unsigned to signed while preserving the underlying binary
  20. // representation.
  21. constexpr __int128 BitCastToSigned(unsigned __int128 v) {
  22. // Casting an unsigned integer to a signed integer of the same
  23. // width is implementation defined behavior if the source value would not fit
  24. // in the destination type. We step around it with a roundtrip bitwise not
  25. // operation to make sure this function remains constexpr. Clang and GCC
  26. // optimize this to a no-op on x86-64.
  27. return v & (static_cast<unsigned __int128>(1) << 127)
  28. ? ~static_cast<__int128>(~v)
  29. : static_cast<__int128>(v);
  30. }
  31. } // namespace int128_internal
  32. inline int128& int128::operator=(__int128 v) {
  33. v_ = v;
  34. return *this;
  35. }
  36. constexpr uint64_t Int128Low64(int128 v) {
  37. return static_cast<uint64_t>(v.v_ & ~uint64_t{0});
  38. }
  39. constexpr int64_t Int128High64(int128 v) {
  40. // Initially cast to unsigned to prevent a right shift on a negative value.
  41. return int128_internal::BitCastToSigned(
  42. static_cast<uint64_t>(static_cast<unsigned __int128>(v.v_) >> 64));
  43. }
  44. constexpr int128::int128(int64_t high, uint64_t low)
  45. // Initially cast to unsigned to prevent a left shift that overflows.
  46. : v_(int128_internal::BitCastToSigned(static_cast<unsigned __int128>(high)
  47. << 64) |
  48. low) {}
  49. constexpr int128::int128(int v) : v_{v} {}
  50. constexpr int128::int128(long v) : v_{v} {} // NOLINT(runtime/int)
  51. constexpr int128::int128(long long v) : v_{v} {} // NOLINT(runtime/int)
  52. constexpr int128::int128(__int128 v) : v_{v} {}
  53. constexpr int128::int128(unsigned int v) : v_{v} {}
  54. constexpr int128::int128(unsigned long v) : v_{v} {} // NOLINT(runtime/int)
  55. // NOLINTNEXTLINE(runtime/int)
  56. constexpr int128::int128(unsigned long long v) : v_{v} {}
  57. constexpr int128::int128(unsigned __int128 v) : v_{static_cast<__int128>(v)} {}
  58. inline int128::int128(float v) {
  59. v_ = static_cast<__int128>(v);
  60. }
  61. inline int128::int128(double v) {
  62. v_ = static_cast<__int128>(v);
  63. }
  64. inline int128::int128(long double v) {
  65. v_ = static_cast<__int128>(v);
  66. }
  67. constexpr int128::int128(uint128 v) : v_{static_cast<__int128>(v)} {}
  68. constexpr int128::operator bool() const { return static_cast<bool>(v_); }
  69. constexpr int128::operator char() const { return static_cast<char>(v_); }
  70. constexpr int128::operator signed char() const {
  71. return static_cast<signed char>(v_);
  72. }
  73. constexpr int128::operator unsigned char() const {
  74. return static_cast<unsigned char>(v_);
  75. }
  76. constexpr int128::operator char16_t() const {
  77. return static_cast<char16_t>(v_);
  78. }
  79. constexpr int128::operator char32_t() const {
  80. return static_cast<char32_t>(v_);
  81. }
  82. constexpr int128::operator Y_ABSL_INTERNAL_WCHAR_T() const {
  83. return static_cast<Y_ABSL_INTERNAL_WCHAR_T>(v_);
  84. }
  85. constexpr int128::operator short() const { // NOLINT(runtime/int)
  86. return static_cast<short>(v_); // NOLINT(runtime/int)
  87. }
  88. constexpr int128::operator unsigned short() const { // NOLINT(runtime/int)
  89. return static_cast<unsigned short>(v_); // NOLINT(runtime/int)
  90. }
  91. constexpr int128::operator int() const {
  92. return static_cast<int>(v_);
  93. }
  94. constexpr int128::operator unsigned int() const {
  95. return static_cast<unsigned int>(v_);
  96. }
  97. constexpr int128::operator long() const { // NOLINT(runtime/int)
  98. return static_cast<long>(v_); // NOLINT(runtime/int)
  99. }
  100. constexpr int128::operator unsigned long() const { // NOLINT(runtime/int)
  101. return static_cast<unsigned long>(v_); // NOLINT(runtime/int)
  102. }
  103. constexpr int128::operator long long() const { // NOLINT(runtime/int)
  104. return static_cast<long long>(v_); // NOLINT(runtime/int)
  105. }
  106. constexpr int128::operator unsigned long long() const { // NOLINT(runtime/int)
  107. return static_cast<unsigned long long>(v_); // NOLINT(runtime/int)
  108. }
  109. constexpr int128::operator __int128() const { return v_; }
  110. constexpr int128::operator unsigned __int128() const {
  111. return static_cast<unsigned __int128>(v_);
  112. }
  113. // Clang on PowerPC sometimes produces incorrect __int128 to floating point
  114. // conversions. In that case, we do the conversion with a similar implementation
  115. // to the conversion operators in int128_no_intrinsic.inc.
  116. #if defined(__clang__) && !defined(__ppc64__)
  117. inline int128::operator float() const { return static_cast<float>(v_); }
  118. inline int128::operator double() const { return static_cast<double>(v_); }
  119. inline int128::operator long double() const {
  120. return static_cast<long double>(v_);
  121. }
  122. #else // Clang on PowerPC
  123. inline int128::operator float() const {
  124. // We must convert the absolute value and then negate as needed, because
  125. // floating point types are typically sign-magnitude. Otherwise, the
  126. // difference between the high and low 64 bits when interpreted as two's
  127. // complement overwhelms the precision of the mantissa.
  128. //
  129. // Also check to make sure we don't negate Int128Min()
  130. return v_ < 0 && *this != Int128Min()
  131. ? -static_cast<float>(-*this)
  132. : static_cast<float>(Int128Low64(*this)) +
  133. std::ldexp(static_cast<float>(Int128High64(*this)), 64);
  134. }
  135. inline int128::operator double() const {
  136. // See comment in int128::operator float() above.
  137. return v_ < 0 && *this != Int128Min()
  138. ? -static_cast<double>(-*this)
  139. : static_cast<double>(Int128Low64(*this)) +
  140. std::ldexp(static_cast<double>(Int128High64(*this)), 64);
  141. }
  142. inline int128::operator long double() const {
  143. // See comment in int128::operator float() above.
  144. return v_ < 0 && *this != Int128Min()
  145. ? -static_cast<long double>(-*this)
  146. : static_cast<long double>(Int128Low64(*this)) +
  147. std::ldexp(static_cast<long double>(Int128High64(*this)),
  148. 64);
  149. }
  150. #endif // Clang on PowerPC
  151. // Comparison operators.
  152. constexpr bool operator==(int128 lhs, int128 rhs) {
  153. return static_cast<__int128>(lhs) == static_cast<__int128>(rhs);
  154. }
  155. constexpr bool operator!=(int128 lhs, int128 rhs) {
  156. return static_cast<__int128>(lhs) != static_cast<__int128>(rhs);
  157. }
  158. constexpr bool operator<(int128 lhs, int128 rhs) {
  159. return static_cast<__int128>(lhs) < static_cast<__int128>(rhs);
  160. }
  161. constexpr bool operator>(int128 lhs, int128 rhs) {
  162. return static_cast<__int128>(lhs) > static_cast<__int128>(rhs);
  163. }
  164. constexpr bool operator<=(int128 lhs, int128 rhs) {
  165. return static_cast<__int128>(lhs) <= static_cast<__int128>(rhs);
  166. }
  167. constexpr bool operator>=(int128 lhs, int128 rhs) {
  168. return static_cast<__int128>(lhs) >= static_cast<__int128>(rhs);
  169. }
  170. // Unary operators.
  171. constexpr int128 operator-(int128 v) { return -static_cast<__int128>(v); }
  172. constexpr bool operator!(int128 v) { return !static_cast<__int128>(v); }
  173. constexpr int128 operator~(int128 val) { return ~static_cast<__int128>(val); }
  174. // Arithmetic operators.
  175. constexpr int128 operator+(int128 lhs, int128 rhs) {
  176. return static_cast<__int128>(lhs) + static_cast<__int128>(rhs);
  177. }
  178. constexpr int128 operator-(int128 lhs, int128 rhs) {
  179. return static_cast<__int128>(lhs) - static_cast<__int128>(rhs);
  180. }
  181. inline int128 operator*(int128 lhs, int128 rhs) {
  182. return static_cast<__int128>(lhs) * static_cast<__int128>(rhs);
  183. }
  184. inline int128 operator/(int128 lhs, int128 rhs) {
  185. return static_cast<__int128>(lhs) / static_cast<__int128>(rhs);
  186. }
  187. inline int128 operator%(int128 lhs, int128 rhs) {
  188. return static_cast<__int128>(lhs) % static_cast<__int128>(rhs);
  189. }
  190. inline int128 int128::operator++(int) {
  191. int128 tmp(*this);
  192. ++v_;
  193. return tmp;
  194. }
  195. inline int128 int128::operator--(int) {
  196. int128 tmp(*this);
  197. --v_;
  198. return tmp;
  199. }
  200. inline int128& int128::operator++() {
  201. ++v_;
  202. return *this;
  203. }
  204. inline int128& int128::operator--() {
  205. --v_;
  206. return *this;
  207. }
  208. constexpr int128 operator|(int128 lhs, int128 rhs) {
  209. return static_cast<__int128>(lhs) | static_cast<__int128>(rhs);
  210. }
  211. constexpr int128 operator&(int128 lhs, int128 rhs) {
  212. return static_cast<__int128>(lhs) & static_cast<__int128>(rhs);
  213. }
  214. constexpr int128 operator^(int128 lhs, int128 rhs) {
  215. return static_cast<__int128>(lhs) ^ static_cast<__int128>(rhs);
  216. }
  217. constexpr int128 operator<<(int128 lhs, int amount) {
  218. return static_cast<__int128>(lhs) << amount;
  219. }
  220. constexpr int128 operator>>(int128 lhs, int amount) {
  221. return static_cast<__int128>(lhs) >> amount;
  222. }