summaryrefslogtreecommitdiff
path: root/absl/numeric/int128_have_intrinsic.inc
blob: 6f1ac644141e937baaf8b95aa6662bba4cd0d36a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
//
// Copyright 2017 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// This file contains :int128 implementation details that depend on internal
// representation when ABSL_HAVE_INTRINSIC_INT128 is defined. This file is
// included by int128.h and relies on ABSL_INTERNAL_WCHAR_T being defined.

namespace int128_internal {

// Casts from unsigned to signed while preserving the underlying binary
// representation.
constexpr __int128 BitCastToSigned(unsigned __int128 v) {
  // Casting an unsigned integer to a signed integer of the same
  // width is implementation defined behavior if the source value would not fit
  // in the destination type. We step around it with a roundtrip bitwise not
  // operation to make sure this function remains constexpr. Clang and GCC
  // optimize this to a no-op on x86-64.
  return v & (static_cast<unsigned __int128>(1) << 127)
             ? ~static_cast<__int128>(~v)
             : static_cast<__int128>(v);
}

}  // namespace int128_internal

inline int128& int128::operator=(__int128 v) {
  v_ = v;
  return *this;
}

constexpr uint64_t Int128Low64(int128 v) {
  return static_cast<uint64_t>(v.v_ & ~uint64_t{0});
}

constexpr int64_t Int128High64(int128 v) {
  // Initially cast to unsigned to prevent a right shift on a negative value.
  return int128_internal::BitCastToSigned(
      static_cast<uint64_t>(static_cast<unsigned __int128>(v.v_) >> 64));
}

constexpr int128::int128(int64_t high, uint64_t low)
    // Initially cast to unsigned to prevent a left shift that overflows.
    : v_(int128_internal::BitCastToSigned(static_cast<unsigned __int128>(high)
                                           << 64) |
         low) {}


constexpr int128::int128(int v) : v_{v} {}

constexpr int128::int128(long v) : v_{v} {}       // NOLINT(runtime/int)

constexpr int128::int128(long long v) : v_{v} {}  // NOLINT(runtime/int)

constexpr int128::int128(__int128 v) : v_{v} {}

constexpr int128::int128(unsigned int v) : v_{v} {}

constexpr int128::int128(unsigned long v) : v_{v} {}  // NOLINT(runtime/int)

// NOLINTNEXTLINE(runtime/int)
constexpr int128::int128(unsigned long long v) : v_{v} {}

constexpr int128::int128(unsigned __int128 v) : v_{static_cast<__int128>(v)} {}

inline int128::int128(float v) {
  v_ = static_cast<__int128>(v);
}

inline int128::int128(double v) {
  v_ = static_cast<__int128>(v);
}

inline int128::int128(long double v) {
  v_ = static_cast<__int128>(v);
}

constexpr int128::int128(uint128 v) : v_{static_cast<__int128>(v)} {}

constexpr int128::operator bool() const { return static_cast<bool>(v_); }

constexpr int128::operator char() const { return static_cast<char>(v_); }

constexpr int128::operator signed char() const {
  return static_cast<signed char>(v_);
}

constexpr int128::operator unsigned char() const {
  return static_cast<unsigned char>(v_);
}

constexpr int128::operator char16_t() const {
  return static_cast<char16_t>(v_);
}

constexpr int128::operator char32_t() const {
  return static_cast<char32_t>(v_);
}

constexpr int128::operator ABSL_INTERNAL_WCHAR_T() const {
  return static_cast<ABSL_INTERNAL_WCHAR_T>(v_);
}

constexpr int128::operator short() const {  // NOLINT(runtime/int)
  return static_cast<short>(v_);            // NOLINT(runtime/int)
}

constexpr int128::operator unsigned short() const {  // NOLINT(runtime/int)
  return static_cast<unsigned short>(v_);            // NOLINT(runtime/int)
}

constexpr int128::operator int() const {
  return static_cast<int>(v_);
}

constexpr int128::operator unsigned int() const {
  return static_cast<unsigned int>(v_);
}

constexpr int128::operator long() const {  // NOLINT(runtime/int)
  return static_cast<long>(v_);            // NOLINT(runtime/int)
}

constexpr int128::operator unsigned long() const {  // NOLINT(runtime/int)
  return static_cast<unsigned long>(v_);            // NOLINT(runtime/int)
}

constexpr int128::operator long long() const {  // NOLINT(runtime/int)
  return static_cast<long long>(v_);            // NOLINT(runtime/int)
}

constexpr int128::operator unsigned long long() const {  // NOLINT(runtime/int)
  return static_cast<unsigned long long>(v_);            // NOLINT(runtime/int)
}

constexpr int128::operator __int128() const { return v_; }

constexpr int128::operator unsigned __int128() const {
  return static_cast<unsigned __int128>(v_);
}

// Clang on PowerPC sometimes produces incorrect __int128 to floating point
// conversions. In that case, we do the conversion with a similar implementation
// to the conversion operators in int128_no_intrinsic.inc.
#if defined(__clang__) && !defined(__ppc64__)
inline int128::operator float() const { return static_cast<float>(v_); }

inline int128::operator double() const { return static_cast<double>(v_); }

inline int128::operator long double() const {
  return static_cast<long double>(v_);
}

#else  // Clang on PowerPC

inline int128::operator float() const {
  // We must convert the absolute value and then negate as needed, because
  // floating point types are typically sign-magnitude. Otherwise, the
  // difference between the high and low 64 bits when interpreted as two's
  // complement overwhelms the precision of the mantissa.
  //
  // Also check to make sure we don't negate Int128Min()
  return v_ < 0 && *this != Int128Min()
             ? -static_cast<float>(-*this)
             : static_cast<float>(Int128Low64(*this)) +
                   std::ldexp(static_cast<float>(Int128High64(*this)), 64);
}

inline int128::operator double() const {
  // See comment in int128::operator float() above.
  return v_ < 0 && *this != Int128Min()
             ? -static_cast<double>(-*this)
             : static_cast<double>(Int128Low64(*this)) +
                   std::ldexp(static_cast<double>(Int128High64(*this)), 64);
}

inline int128::operator long double() const {
  // See comment in int128::operator float() above.
  return v_ < 0 && *this != Int128Min()
             ? -static_cast<long double>(-*this)
             : static_cast<long double>(Int128Low64(*this)) +
                   std::ldexp(static_cast<long double>(Int128High64(*this)),
                              64);
}
#endif  // Clang on PowerPC

// Comparison operators.

constexpr bool operator==(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) == static_cast<__int128>(rhs);
}

constexpr bool operator!=(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) != static_cast<__int128>(rhs);
}

constexpr bool operator<(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) < static_cast<__int128>(rhs);
}

constexpr bool operator>(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) > static_cast<__int128>(rhs);
}

constexpr bool operator<=(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) <= static_cast<__int128>(rhs);
}

constexpr bool operator>=(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) >= static_cast<__int128>(rhs);
}

// Unary operators.

constexpr int128 operator-(int128 v) { return -static_cast<__int128>(v); }

constexpr bool operator!(int128 v) { return !static_cast<__int128>(v); }

constexpr int128 operator~(int128 val) { return ~static_cast<__int128>(val); }

// Arithmetic operators.

constexpr int128 operator+(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) + static_cast<__int128>(rhs);
}

constexpr int128 operator-(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) - static_cast<__int128>(rhs);
}

inline int128 operator*(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) * static_cast<__int128>(rhs);
}

inline int128 operator/(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) / static_cast<__int128>(rhs);
}

inline int128 operator%(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) % static_cast<__int128>(rhs);
}

inline int128 int128::operator++(int) {
  int128 tmp(*this);
  ++v_;
  return tmp;
}

inline int128 int128::operator--(int) {
  int128 tmp(*this);
  --v_;
  return tmp;
}

inline int128& int128::operator++() {
  ++v_;
  return *this;
}

inline int128& int128::operator--() {
  --v_;
  return *this;
}

constexpr int128 operator|(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) | static_cast<__int128>(rhs);
}

constexpr int128 operator&(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) & static_cast<__int128>(rhs);
}

constexpr int128 operator^(int128 lhs, int128 rhs) {
  return static_cast<__int128>(lhs) ^ static_cast<__int128>(rhs);
}

constexpr int128 operator<<(int128 lhs, int amount) {
  return static_cast<__int128>(lhs) << amount;
}

constexpr int128 operator>>(int128 lhs, int amount) {
  return static_cast<__int128>(lhs) >> amount;
}