/
int.hpp
394 lines (365 loc) · 10.2 KB
/
int.hpp
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
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
#ifndef GRNXX_DATA_TYPES_SCALAR_INT_HPP
#define GRNXX_DATA_TYPES_SCALAR_INT_HPP
#include <cstdint>
#include <limits>
#include "grnxx/features.hpp"
#include "grnxx/data_types/na.hpp"
namespace grnxx {
// NOTE: This implementation assumes two's complement.
class Int {
public:
Int() = default;
~Int() = default;
constexpr Int(const Int &) = default;
Int &operator=(const Int &) = default;
explicit constexpr Int(int64_t value) : value_(value) {}
explicit constexpr Int(NA) : value_(na_value()) {}
constexpr int64_t value() const {
return value_;
}
constexpr bool is_min() const {
return value_ == min_value();
}
constexpr bool is_max() const {
return value_ == max_value();
}
constexpr bool is_na() const {
return value_ == na_value();
}
// -- Unary operators --
constexpr Int operator+() const {
return *this;
}
// NOTE: This implementation assumes that -na_value() returns na_value(),
// although -na_value() in two's complement causes an overflow and
// the behavior is undefined in C/C++.
// If this assumption is wrong, N/A must be excluded.
constexpr Int operator-() const {
return Int(-value_);
}
constexpr Int operator~() const {
return is_na() ? na() : Int(~value_);
}
Int &operator++() & {
if (!is_na()) {
++value_;
}
return *this;
}
Int operator++(int) & {
if (is_na()) {
return na();
}
return Int(value_++);
}
Int &operator--() & {
if (!is_na()) {
--value_;
}
return *this;
}
Int operator--(int) & {
if (is_na()) {
return na();
}
return Int(value_--);
}
// -- Binary operators --
constexpr Int operator&(Int rhs) const {
return (is_na() || rhs.is_na()) ? na() : Int(value_ & rhs.value_);
}
constexpr Int operator|(Int rhs) const {
return (is_na() || rhs.is_na()) ? na() : Int(value_ | rhs.value_);
}
constexpr Int operator^(Int rhs) const {
return (is_na() || rhs.is_na()) ? na() : Int(value_ ^ rhs.value_);
}
Int &operator&=(Int rhs) & {
if (!is_na()) {
value_ = rhs.is_na() ? na_value() : (value_ & rhs.value_);
}
return *this;
}
Int &operator|=(Int rhs) & {
if (!is_na()) {
value_ = rhs.is_na() ? na_value() : (value_ | rhs.value_);
}
return *this;
}
Int &operator^=(Int rhs) & {
if (!is_na()) {
value_ = rhs.is_na() ? na_value() : (value_ ^ rhs.value_);
}
return *this;
}
// -- Bitwise shift operators --
constexpr Int operator<<(Int rhs) const {
return (is_na() || rhs.is_na() ||
(static_cast<uint64_t>(rhs.value_) >= 64)) ?
na() : Int(value_ << rhs.value_);
}
// NOTE: This is an arithmetic shift.
constexpr Int operator>>(Int rhs) const {
return arithmetic_right_shift(rhs);
}
Int &operator<<=(Int rhs) & {
if (!is_na()) {
if (rhs.is_na() || (static_cast<uint64_t>(rhs.value_) >= 64)) {
value_ = na_value();
} else {
value_ <<= rhs.value_;
}
}
return *this;
}
// NOTE: This is an arithmetic shift.
Int &operator>>=(Int rhs) & {
if (!is_na()) {
if (rhs.is_na() || (static_cast<uint64_t>(rhs.value_) >= 64)) {
value_ = na_value();
} else {
value_ >>= rhs.value_;
}
}
return *this;
}
constexpr Int arithmetic_right_shift(Int rhs) const {
return (is_na() || rhs.is_na() ||
(static_cast<uint64_t>(rhs.value_) >= 64)) ?
na() : Int(value_ >> rhs.value_);
}
constexpr Int logical_right_shift(Int rhs) const {
return (is_na() || rhs.is_na() ||
(static_cast<uint64_t>(rhs.value_) >= 64)) ?
na() : Int(static_cast<uint64_t>(value_) >> rhs.value_);
}
// -- Arithmetic operators --
// NOTE: C++11 does not allow `if` in constexpr function, but C++14 does.
Int operator+(Int rhs) const {
return add(*this, rhs);
}
Int operator-(Int rhs) const {
return subtract(*this, rhs);
}
Int operator*(Int rhs) const {
return multiply(*this, rhs);
};
Int operator/(Int rhs) const {
return (is_na() || rhs.is_na() || (rhs.value_ == 0)) ?
na() : Int(value_ / rhs.value_);
}
Int operator%(Int rhs) const {
return (is_na() || rhs.is_na() || (rhs.value_ == 0)) ?
na() : Int(value_ % rhs.value_);
}
Int &operator+=(Int rhs) & {
return *this = operator+(rhs);
}
Int &operator-=(Int rhs) & {
return *this = operator-(rhs);
}
Int &operator*=(Int rhs) & {
return *this = operator*(rhs);
}
Int &operator/=(Int rhs) &{
if (!is_na()) {
value_ = (rhs.is_na() || (rhs.value_ == 0)) ?
na_value() : (value_ / rhs.value_);
}
return *this;
}
Int &operator%=(Int rhs) &{
if (!is_na()) {
value_ = (rhs.is_na() || (rhs.value_ == 0)) ?
na_value() : (value_ % rhs.value_);
}
return *this;
}
// -- Comparison operators --
constexpr Bool operator==(Int rhs) const {
return (is_na() || rhs.is_na()) ? Bool::na() : Bool(value_ == rhs.value_);
}
constexpr Bool operator!=(Int rhs) const {
return (is_na() || rhs.is_na()) ? Bool::na() : Bool(value_ != rhs.value_);
}
constexpr Bool operator<(Int rhs) const {
return (is_na() || rhs.is_na()) ? Bool::na() : Bool(value_ < rhs.value_);
}
constexpr Bool operator>(Int rhs) const {
return (is_na() || rhs.is_na()) ? Bool::na() : Bool(value_ > rhs.value_);
}
constexpr Bool operator<=(Int rhs) const {
return (is_na() || rhs.is_na()) ? Bool::na() : Bool(value_ <= rhs.value_);
}
constexpr Bool operator>=(Int rhs) const {
return (is_na() || rhs.is_na()) ? Bool::na() : Bool(value_ >= rhs.value_);
}
static constexpr Int min() {
return Int(min_value());
}
static constexpr Int max() {
return Int(max_value());
}
static constexpr Int na() {
return Int(NA());
}
static constexpr int64_t min_value() {
return std::numeric_limits<int64_t>::min() + 1;
}
static constexpr int64_t max_value() {
return std::numeric_limits<int64_t>::max();
}
static constexpr int64_t na_value() {
return std::numeric_limits<int64_t>::min();
}
private:
int64_t value_;
#if defined(GRNXX_GNUC) && defined(GRNXX_X86_64)
// TODO: Implementations for MSC should be written.
// NOTE: These implementations use x86_64 instructions for speed.
static Int add(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
__asm__ ("ADD %1, %0;"
"JNO GRNXX_INT_ADD_OVERFLOW%=;"
"MOV %2, %0;"
"GRNXX_INT_ADD_OVERFLOW%=:"
: "+r" (lhs.value_)
: "r" (rhs.value_), "r" (na_value())
: "cc");
return lhs;
}
static Int subtract(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
__asm__ ("SUB %1, %0;"
"JNO GRNXX_INT_SUBTRACT_OVERFLOW%=;"
"MOV %2, %0;"
"GRNXX_INT_SUBTRACT_OVERFLOW%=:"
: "+r" (lhs.value_)
: "r" (rhs.value_), "r" (na_value())
: "cc");
return lhs;
}
static Int multiply(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
__asm__ ("IMUL %1, %0;"
"JNO GRNXX_INT_MULTIPLY_OVERFLOW%=;"
"MOV %2, %0;"
"GRNXX_INT_MULTIPLY_OVERFLOW%=:"
: "+r" (lhs.value_)
: "r" (rhs.value_), "r" (na_value())
: "cc");
return lhs;
}
#elif defined(GRNXX_WRAP_AROUND)
// TODO: The following implementations should be used if the above
// implementations are not available.
// NOTE: These implementations assume silent two's complement wrap-around.
// The C/C++ standards say that a signed integer overflow causes
// undefined behavior.
static Int add(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
int64_t result_value = lhs.value_ + rhs.value_;
lhs.value_ ^= result_value;
rhs.value_ ^= result_value;
if (static_cast<uint64_t>(lhs.value_ & rhs.value_) >> 63) {
return na();
}
return Int(result_value);
}
static Int subtract(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
int64_t result_value = lhs.value_ - rhs.value_;
lhs.value_ ^= result_value;
rhs.value_ ^= result_value;
if (static_cast<uint64_t>(lhs.value_ & rhs.value_) >> 63) {
return na();
}
return Int(result_value);
}
static Int multiply(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
if (rhs.value_ == 0) {
return Int(0);
}
int64_t result = lhs.value_ * rhs.value_;
if ((result / rhs.value_) != lhs.value_) {
return na();
}
return Int(result);
}
# else // defined(GRNXX_WRAP_AROUND)
// NOTE: These implementations are portable but slow.
static Int add(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
if (lhs.value_ >= 0) {
if (rhs.value_ > (max_value() - lhs.value_)) {
return na();
}
} else {
if (rhs.value_ < (min_value() - lhs.value_)) {
return na();
}
}
return Int(lhs.value_ + rhs.value_);
}
static Int subtract(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
if (rhs.value_ >= 0) {
if (lhs.value_ < (min_value() + rhs.value_)) {
return na();
}
} else {
if (lhs.value_ > (max_value() + rhs.value_)) {
return na();
}
}
return Int(lhs.value_ - rhs.value_);
}
static Int multiply(Int lhs, Int rhs) {
if (lhs.is_na() || rhs.is_na()) {
return na();
}
if (rhs.value_ == 0) {
return Int(0);
}
if (lhs.value_ >= 0) {
if (rhs.value_ > 0) {
if (lhs.value_ > (max_value() / rhs.value_)) {
return na();
}
} else {
if (lhs.value_ > (min_value() / rhs.value_)) {
return na();
}
}
} else if (rhs.value_ > 0) {
if (lhs.value_ < (min_value() / rhs.value_)) {
return na();
}
} else {
if (lhs.value_ < (max_value() / rhs.value_)) {
return na();
}
}
return Int(lhs.value_ * rhs.value_);
}
# endif // GRNXX_WRAP_AROUND
};
} // namespace grnxx
#endif // GRNXX_DATA_TYPES_SCALAR_INT_HPP