1 // Copyright 2017 The Abseil Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "absl/numeric/int128.h"
16
17 #include <algorithm>
18 #include <limits>
19 #include <random>
20 #include <type_traits>
21 #include <utility>
22 #include <vector>
23
24 #include "gtest/gtest.h"
25 #include "absl/base/internal/cycleclock.h"
26 #include "absl/hash/hash_testing.h"
27 #include "absl/meta/type_traits.h"
28 #include "absl/types/compare.h"
29
30 #define MAKE_INT128(HI, LO) absl::MakeInt128(static_cast<int64_t>(HI), LO)
31
32 namespace {
33
34 template <typename T>
35 class Uint128IntegerTraitsTest : public ::testing::Test {};
36 typedef ::testing::Types<bool, char, signed char, unsigned char, char16_t,
37 char32_t, wchar_t,
38 short, // NOLINT(runtime/int)
39 unsigned short, // NOLINT(runtime/int)
40 int, unsigned int,
41 long, // NOLINT(runtime/int)
42 unsigned long, // NOLINT(runtime/int)
43 long long, // NOLINT(runtime/int)
44 unsigned long long> // NOLINT(runtime/int)
45 IntegerTypes;
46
47 template <typename T>
48 class Uint128FloatTraitsTest : public ::testing::Test {};
49 typedef ::testing::Types<float, double, long double> FloatingPointTypes;
50
51 TYPED_TEST_SUITE(Uint128IntegerTraitsTest, IntegerTypes);
52
TYPED_TEST(Uint128IntegerTraitsTest,ConstructAssignTest)53 TYPED_TEST(Uint128IntegerTraitsTest, ConstructAssignTest) {
54 static_assert(std::is_constructible<absl::uint128, TypeParam>::value,
55 "absl::uint128 must be constructible from TypeParam");
56 static_assert(std::is_assignable<absl::uint128&, TypeParam>::value,
57 "absl::uint128 must be assignable from TypeParam");
58 static_assert(!std::is_assignable<TypeParam&, absl::uint128>::value,
59 "TypeParam must not be assignable from absl::uint128");
60 }
61
62 TYPED_TEST_SUITE(Uint128FloatTraitsTest, FloatingPointTypes);
63
TYPED_TEST(Uint128FloatTraitsTest,ConstructAssignTest)64 TYPED_TEST(Uint128FloatTraitsTest, ConstructAssignTest) {
65 static_assert(std::is_constructible<absl::uint128, TypeParam>::value,
66 "absl::uint128 must be constructible from TypeParam");
67 static_assert(!std::is_assignable<absl::uint128&, TypeParam>::value,
68 "absl::uint128 must not be assignable from TypeParam");
69 static_assert(!std::is_assignable<TypeParam&, absl::uint128>::value,
70 "TypeParam must not be assignable from absl::uint128");
71 }
72
73 #ifdef ABSL_HAVE_INTRINSIC_INT128
74 // These type traits done separately as TYPED_TEST requires typeinfo, and not
75 // all platforms have this for __int128 even though they define the type.
TEST(Uint128,IntrinsicTypeTraitsTest)76 TEST(Uint128, IntrinsicTypeTraitsTest) {
77 static_assert(std::is_constructible<absl::uint128, __int128>::value,
78 "absl::uint128 must be constructible from __int128");
79 static_assert(std::is_assignable<absl::uint128&, __int128>::value,
80 "absl::uint128 must be assignable from __int128");
81 static_assert(!std::is_assignable<__int128&, absl::uint128>::value,
82 "__int128 must not be assignable from absl::uint128");
83
84 static_assert(std::is_constructible<absl::uint128, unsigned __int128>::value,
85 "absl::uint128 must be constructible from unsigned __int128");
86 static_assert(std::is_assignable<absl::uint128&, unsigned __int128>::value,
87 "absl::uint128 must be assignable from unsigned __int128");
88 static_assert(!std::is_assignable<unsigned __int128&, absl::uint128>::value,
89 "unsigned __int128 must not be assignable from absl::uint128");
90 }
91 #endif // ABSL_HAVE_INTRINSIC_INT128
92
TEST(Uint128,TrivialTraitsTest)93 TEST(Uint128, TrivialTraitsTest) {
94 static_assert(absl::is_trivially_default_constructible<absl::uint128>::value,
95 "");
96 static_assert(absl::is_trivially_copy_constructible<absl::uint128>::value,
97 "");
98 static_assert(absl::is_trivially_copy_assignable<absl::uint128>::value, "");
99 static_assert(std::is_trivially_destructible<absl::uint128>::value, "");
100 }
101
TEST(Uint128,AllTests)102 TEST(Uint128, AllTests) {
103 absl::uint128 zero = 0;
104 absl::uint128 one = 1;
105 absl::uint128 one_2arg = absl::MakeUint128(0, 1);
106 absl::uint128 two = 2;
107 absl::uint128 three = 3;
108 absl::uint128 big = absl::MakeUint128(2000, 2);
109 absl::uint128 big_minus_one = absl::MakeUint128(2000, 1);
110 absl::uint128 bigger = absl::MakeUint128(2001, 1);
111 absl::uint128 biggest = absl::Uint128Max();
112 absl::uint128 high_low = absl::MakeUint128(1, 0);
113 absl::uint128 low_high =
114 absl::MakeUint128(0, std::numeric_limits<uint64_t>::max());
115 EXPECT_LT(one, two);
116 EXPECT_GT(two, one);
117 EXPECT_LT(one, big);
118 EXPECT_LT(one, big);
119 EXPECT_EQ(one, one_2arg);
120 EXPECT_NE(one, two);
121 EXPECT_GT(big, one);
122 EXPECT_GE(big, two);
123 EXPECT_GE(big, big_minus_one);
124 EXPECT_GT(big, big_minus_one);
125 EXPECT_LT(big_minus_one, big);
126 EXPECT_LE(big_minus_one, big);
127 EXPECT_NE(big_minus_one, big);
128 EXPECT_LT(big, biggest);
129 EXPECT_LE(big, biggest);
130 EXPECT_GT(biggest, big);
131 EXPECT_GE(biggest, big);
132 EXPECT_EQ(big, ~~big);
133 EXPECT_EQ(one, one | one);
134 EXPECT_EQ(big, big | big);
135 EXPECT_EQ(one, one | zero);
136 EXPECT_EQ(one, one & one);
137 EXPECT_EQ(big, big & big);
138 EXPECT_EQ(zero, one & zero);
139 EXPECT_EQ(zero, big & ~big);
140 EXPECT_EQ(zero, one ^ one);
141 EXPECT_EQ(zero, big ^ big);
142 EXPECT_EQ(one, one ^ zero);
143
144 // Shift operators.
145 EXPECT_EQ(big, big << 0);
146 EXPECT_EQ(big, big >> 0);
147 EXPECT_GT(big << 1, big);
148 EXPECT_LT(big >> 1, big);
149 EXPECT_EQ(big, (big << 10) >> 10);
150 EXPECT_EQ(big, (big >> 1) << 1);
151 EXPECT_EQ(one, (one << 80) >> 80);
152 EXPECT_EQ(zero, (one >> 80) << 80);
153
154 // Shift assignments.
155 absl::uint128 big_copy = big;
156 EXPECT_EQ(big << 0, big_copy <<= 0);
157 big_copy = big;
158 EXPECT_EQ(big >> 0, big_copy >>= 0);
159 big_copy = big;
160 EXPECT_EQ(big << 1, big_copy <<= 1);
161 big_copy = big;
162 EXPECT_EQ(big >> 1, big_copy >>= 1);
163 big_copy = big;
164 EXPECT_EQ(big << 10, big_copy <<= 10);
165 big_copy = big;
166 EXPECT_EQ(big >> 10, big_copy >>= 10);
167 big_copy = big;
168 EXPECT_EQ(big << 64, big_copy <<= 64);
169 big_copy = big;
170 EXPECT_EQ(big >> 64, big_copy >>= 64);
171 big_copy = big;
172 EXPECT_EQ(big << 73, big_copy <<= 73);
173 big_copy = big;
174 EXPECT_EQ(big >> 73, big_copy >>= 73);
175
176 EXPECT_EQ(absl::Uint128High64(biggest), std::numeric_limits<uint64_t>::max());
177 EXPECT_EQ(absl::Uint128Low64(biggest), std::numeric_limits<uint64_t>::max());
178 EXPECT_EQ(zero + one, one);
179 EXPECT_EQ(one + one, two);
180 EXPECT_EQ(big_minus_one + one, big);
181 EXPECT_EQ(one - one, zero);
182 EXPECT_EQ(one - zero, one);
183 EXPECT_EQ(zero - one, biggest);
184 EXPECT_EQ(big - big, zero);
185 EXPECT_EQ(big - one, big_minus_one);
186 EXPECT_EQ(big + std::numeric_limits<uint64_t>::max(), bigger);
187 EXPECT_EQ(biggest + 1, zero);
188 EXPECT_EQ(zero - 1, biggest);
189 EXPECT_EQ(high_low - one, low_high);
190 EXPECT_EQ(low_high + one, high_low);
191 EXPECT_EQ(absl::Uint128High64((absl::uint128(1) << 64) - 1), 0);
192 EXPECT_EQ(absl::Uint128Low64((absl::uint128(1) << 64) - 1),
193 std::numeric_limits<uint64_t>::max());
194 EXPECT_TRUE(!!one);
195 EXPECT_TRUE(!!high_low);
196 EXPECT_FALSE(!!zero);
197 EXPECT_FALSE(!one);
198 EXPECT_FALSE(!high_low);
199 EXPECT_TRUE(!zero);
200 EXPECT_TRUE(zero == 0); // NOLINT(readability/check)
201 EXPECT_FALSE(zero != 0); // NOLINT(readability/check)
202 EXPECT_FALSE(one == 0); // NOLINT(readability/check)
203 EXPECT_TRUE(one != 0); // NOLINT(readability/check)
204 EXPECT_FALSE(high_low == 0); // NOLINT(readability/check)
205 EXPECT_TRUE(high_low != 0); // NOLINT(readability/check)
206
207 absl::uint128 test = zero;
208 EXPECT_EQ(++test, one);
209 EXPECT_EQ(test, one);
210 EXPECT_EQ(test++, one);
211 EXPECT_EQ(test, two);
212 EXPECT_EQ(test -= 2, zero);
213 EXPECT_EQ(test, zero);
214 EXPECT_EQ(test += 2, two);
215 EXPECT_EQ(test, two);
216 EXPECT_EQ(--test, one);
217 EXPECT_EQ(test, one);
218 EXPECT_EQ(test--, one);
219 EXPECT_EQ(test, zero);
220 EXPECT_EQ(test |= three, three);
221 EXPECT_EQ(test &= one, one);
222 EXPECT_EQ(test ^= three, two);
223 EXPECT_EQ(test >>= 1, one);
224 EXPECT_EQ(test <<= 1, two);
225
226 EXPECT_EQ(big, +big);
227 EXPECT_EQ(two, +two);
228 EXPECT_EQ(absl::Uint128Max(), +absl::Uint128Max());
229 EXPECT_EQ(zero, +zero);
230
231 EXPECT_EQ(big, -(-big));
232 EXPECT_EQ(two, -((-one) - 1));
233 EXPECT_EQ(absl::Uint128Max(), -one);
234 EXPECT_EQ(zero, -zero);
235 }
236
TEST(Int128,RightShiftOfNegativeNumbers)237 TEST(Int128, RightShiftOfNegativeNumbers) {
238 absl::int128 minus_six = -6;
239 absl::int128 minus_three = -3;
240 absl::int128 minus_two = -2;
241 absl::int128 minus_one = -1;
242 if ((-6 >> 1) == -3) {
243 // Right shift is arithmetic (sign propagates)
244 EXPECT_EQ(minus_six >> 1, minus_three);
245 EXPECT_EQ(minus_six >> 2, minus_two);
246 EXPECT_EQ(minus_six >> 65, minus_one);
247 } else {
248 // Right shift is logical (zeros shifted in at MSB)
249 EXPECT_EQ(minus_six >> 1, absl::int128(absl::uint128(minus_six) >> 1));
250 EXPECT_EQ(minus_six >> 2, absl::int128(absl::uint128(minus_six) >> 2));
251 EXPECT_EQ(minus_six >> 65, absl::int128(absl::uint128(minus_six) >> 65));
252 }
253 }
254
TEST(Uint128,ConversionTests)255 TEST(Uint128, ConversionTests) {
256 EXPECT_TRUE(absl::MakeUint128(1, 0));
257
258 #ifdef ABSL_HAVE_INTRINSIC_INT128
259 unsigned __int128 intrinsic =
260 (static_cast<unsigned __int128>(0x3a5b76c209de76f6) << 64) +
261 0x1f25e1d63a2b46c5;
262 absl::uint128 custom =
263 absl::MakeUint128(0x3a5b76c209de76f6, 0x1f25e1d63a2b46c5);
264
265 EXPECT_EQ(custom, absl::uint128(intrinsic));
266 EXPECT_EQ(custom, absl::uint128(static_cast<__int128>(intrinsic)));
267 EXPECT_EQ(intrinsic, static_cast<unsigned __int128>(custom));
268 EXPECT_EQ(intrinsic, static_cast<__int128>(custom));
269 #endif // ABSL_HAVE_INTRINSIC_INT128
270
271 // verify that an integer greater than 2**64 that can be stored precisely
272 // inside a double is converted to a absl::uint128 without loss of
273 // information.
274 double precise_double = 0x530e * std::pow(2.0, 64.0) + 0xda74000000000000;
275 absl::uint128 from_precise_double(precise_double);
276 absl::uint128 from_precise_ints =
277 absl::MakeUint128(0x530e, 0xda74000000000000);
278 EXPECT_EQ(from_precise_double, from_precise_ints);
279 EXPECT_DOUBLE_EQ(static_cast<double>(from_precise_ints), precise_double);
280
281 double approx_double =
282 static_cast<double>(0xffffeeeeddddcccc) * std::pow(2.0, 64.0) +
283 static_cast<double>(0xbbbbaaaa99998888);
284 absl::uint128 from_approx_double(approx_double);
285 EXPECT_DOUBLE_EQ(static_cast<double>(from_approx_double), approx_double);
286
287 double round_to_zero = 0.7;
288 double round_to_five = 5.8;
289 double round_to_nine = 9.3;
290 EXPECT_EQ(static_cast<absl::uint128>(round_to_zero), 0);
291 EXPECT_EQ(static_cast<absl::uint128>(round_to_five), 5);
292 EXPECT_EQ(static_cast<absl::uint128>(round_to_nine), 9);
293
294 absl::uint128 highest_precision_in_long_double =
295 ~absl::uint128{} >> (128 - std::numeric_limits<long double>::digits);
296 EXPECT_EQ(highest_precision_in_long_double,
297 static_cast<absl::uint128>(
298 static_cast<long double>(highest_precision_in_long_double)));
299 // Apply a mask just to make sure all the bits are the right place.
300 const absl::uint128 arbitrary_mask =
301 absl::MakeUint128(0xa29f622677ded751, 0xf8ca66add076f468);
302 EXPECT_EQ(highest_precision_in_long_double & arbitrary_mask,
303 static_cast<absl::uint128>(static_cast<long double>(
304 highest_precision_in_long_double & arbitrary_mask)));
305
306 EXPECT_EQ(static_cast<absl::uint128>(-0.1L), 0);
307 }
308
TEST(Uint128,OperatorAssignReturnRef)309 TEST(Uint128, OperatorAssignReturnRef) {
310 absl::uint128 v(1);
311 (v += 4) -= 3;
312 EXPECT_EQ(2, v);
313 }
314
TEST(Uint128,Multiply)315 TEST(Uint128, Multiply) {
316 absl::uint128 a, b, c;
317
318 // Zero test.
319 a = 0;
320 b = 0;
321 c = a * b;
322 EXPECT_EQ(0, c);
323
324 // Max carries.
325 a = absl::uint128(0) - 1;
326 b = absl::uint128(0) - 1;
327 c = a * b;
328 EXPECT_EQ(1, c);
329
330 // Self-operation with max carries.
331 c = absl::uint128(0) - 1;
332 c *= c;
333 EXPECT_EQ(1, c);
334
335 // 1-bit x 1-bit.
336 for (int i = 0; i < 64; ++i) {
337 for (int j = 0; j < 64; ++j) {
338 a = absl::uint128(1) << i;
339 b = absl::uint128(1) << j;
340 c = a * b;
341 EXPECT_EQ(absl::uint128(1) << (i + j), c);
342 }
343 }
344
345 // Verified with dc.
346 a = absl::MakeUint128(0xffffeeeeddddcccc, 0xbbbbaaaa99998888);
347 b = absl::MakeUint128(0x7777666655554444, 0x3333222211110000);
348 c = a * b;
349 EXPECT_EQ(absl::MakeUint128(0x530EDA741C71D4C3, 0xBF25975319080000), c);
350 EXPECT_EQ(0, c - b * a);
351 EXPECT_EQ(a*a - b*b, (a+b) * (a-b));
352
353 // Verified with dc.
354 a = absl::MakeUint128(0x0123456789abcdef, 0xfedcba9876543210);
355 b = absl::MakeUint128(0x02468ace13579bdf, 0xfdb97531eca86420);
356 c = a * b;
357 EXPECT_EQ(absl::MakeUint128(0x97a87f4f261ba3f2, 0x342d0bbf48948200), c);
358 EXPECT_EQ(0, c - b * a);
359 EXPECT_EQ(a*a - b*b, (a+b) * (a-b));
360 }
361
TEST(Uint128,AliasTests)362 TEST(Uint128, AliasTests) {
363 absl::uint128 x1 = absl::MakeUint128(1, 2);
364 absl::uint128 x2 = absl::MakeUint128(2, 4);
365 x1 += x1;
366 EXPECT_EQ(x2, x1);
367
368 absl::uint128 x3 = absl::MakeUint128(1, static_cast<uint64_t>(1) << 63);
369 absl::uint128 x4 = absl::MakeUint128(3, 0);
370 x3 += x3;
371 EXPECT_EQ(x4, x3);
372 }
373
TEST(Uint128,DivideAndMod)374 TEST(Uint128, DivideAndMod) {
375 using std::swap;
376
377 // a := q * b + r
378 absl::uint128 a, b, q, r;
379
380 // Zero test.
381 a = 0;
382 b = 123;
383 q = a / b;
384 r = a % b;
385 EXPECT_EQ(0, q);
386 EXPECT_EQ(0, r);
387
388 a = absl::MakeUint128(0x530eda741c71d4c3, 0xbf25975319080000);
389 q = absl::MakeUint128(0x4de2cab081, 0x14c34ab4676e4bab);
390 b = absl::uint128(0x1110001);
391 r = absl::uint128(0x3eb455);
392 ASSERT_EQ(a, q * b + r); // Sanity-check.
393
394 absl::uint128 result_q, result_r;
395 result_q = a / b;
396 result_r = a % b;
397 EXPECT_EQ(q, result_q);
398 EXPECT_EQ(r, result_r);
399
400 // Try the other way around.
401 swap(q, b);
402 result_q = a / b;
403 result_r = a % b;
404 EXPECT_EQ(q, result_q);
405 EXPECT_EQ(r, result_r);
406 // Restore.
407 swap(b, q);
408
409 // Dividend < divisor; result should be q:0 r:<dividend>.
410 swap(a, b);
411 result_q = a / b;
412 result_r = a % b;
413 EXPECT_EQ(0, result_q);
414 EXPECT_EQ(a, result_r);
415 // Try the other way around.
416 swap(a, q);
417 result_q = a / b;
418 result_r = a % b;
419 EXPECT_EQ(0, result_q);
420 EXPECT_EQ(a, result_r);
421 // Restore.
422 swap(q, a);
423 swap(b, a);
424
425 // Try a large remainder.
426 b = a / 2 + 1;
427 absl::uint128 expected_r =
428 absl::MakeUint128(0x29876d3a0e38ea61, 0xdf92cba98c83ffff);
429 // Sanity checks.
430 ASSERT_EQ(a / 2 - 1, expected_r);
431 ASSERT_EQ(a, b + expected_r);
432 result_q = a / b;
433 result_r = a % b;
434 EXPECT_EQ(1, result_q);
435 EXPECT_EQ(expected_r, result_r);
436 }
437
TEST(Uint128,DivideAndModRandomInputs)438 TEST(Uint128, DivideAndModRandomInputs) {
439 const int kNumIters = 1 << 18;
440 std::minstd_rand random(testing::UnitTest::GetInstance()->random_seed());
441 std::uniform_int_distribution<uint64_t> uniform_uint64;
442 for (int i = 0; i < kNumIters; ++i) {
443 const absl::uint128 a =
444 absl::MakeUint128(uniform_uint64(random), uniform_uint64(random));
445 const absl::uint128 b =
446 absl::MakeUint128(uniform_uint64(random), uniform_uint64(random));
447 if (b == 0) {
448 continue; // Avoid a div-by-zero.
449 }
450 const absl::uint128 q = a / b;
451 const absl::uint128 r = a % b;
452 ASSERT_EQ(a, b * q + r);
453 }
454 }
455
TEST(Uint128,ConstexprTest)456 TEST(Uint128, ConstexprTest) {
457 constexpr absl::uint128 zero = absl::uint128();
458 constexpr absl::uint128 one = 1;
459 constexpr absl::uint128 minus_two = -2;
460 EXPECT_EQ(zero, absl::uint128(0));
461 EXPECT_EQ(one, absl::uint128(1));
462 EXPECT_EQ(minus_two, absl::MakeUint128(-1, -2));
463 }
464
TEST(Uint128,NumericLimitsTest)465 TEST(Uint128, NumericLimitsTest) {
466 static_assert(std::numeric_limits<absl::uint128>::is_specialized, "");
467 static_assert(!std::numeric_limits<absl::uint128>::is_signed, "");
468 static_assert(std::numeric_limits<absl::uint128>::is_integer, "");
469 EXPECT_EQ(static_cast<int>(128 * std::log10(2)),
470 std::numeric_limits<absl::uint128>::digits10);
471 EXPECT_EQ(0, std::numeric_limits<absl::uint128>::min());
472 EXPECT_EQ(0, std::numeric_limits<absl::uint128>::lowest());
473 EXPECT_EQ(absl::Uint128Max(), std::numeric_limits<absl::uint128>::max());
474 }
475
TEST(Uint128,Hash)476 TEST(Uint128, Hash) {
477 EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly({
478 // Some simple values
479 absl::uint128{0},
480 absl::uint128{1},
481 ~absl::uint128{},
482 // 64 bit limits
483 absl::uint128{std::numeric_limits<int64_t>::max()},
484 absl::uint128{std::numeric_limits<uint64_t>::max()} + 0,
485 absl::uint128{std::numeric_limits<uint64_t>::max()} + 1,
486 absl::uint128{std::numeric_limits<uint64_t>::max()} + 2,
487 // Keeping high same
488 absl::uint128{1} << 62,
489 absl::uint128{1} << 63,
490 // Keeping low same
491 absl::uint128{1} << 64,
492 absl::uint128{1} << 65,
493 // 128 bit limits
494 std::numeric_limits<absl::uint128>::max(),
495 std::numeric_limits<absl::uint128>::max() - 1,
496 std::numeric_limits<absl::uint128>::min() + 1,
497 std::numeric_limits<absl::uint128>::min(),
498 }));
499 }
500
501
TEST(Int128Uint128,ConversionTest)502 TEST(Int128Uint128, ConversionTest) {
503 absl::int128 nonnegative_signed_values[] = {
504 0,
505 1,
506 0xffeeddccbbaa9988,
507 absl::MakeInt128(0x7766554433221100, 0),
508 absl::MakeInt128(0x1234567890abcdef, 0xfedcba0987654321),
509 absl::Int128Max()};
510 for (absl::int128 value : nonnegative_signed_values) {
511 EXPECT_EQ(value, absl::int128(absl::uint128(value)));
512
513 absl::uint128 assigned_value;
514 assigned_value = value;
515 EXPECT_EQ(value, absl::int128(assigned_value));
516 }
517
518 absl::int128 negative_values[] = {
519 -1, -0x1234567890abcdef,
520 absl::MakeInt128(-0x5544332211ffeedd, 0),
521 -absl::MakeInt128(0x76543210fedcba98, 0xabcdef0123456789)};
522 for (absl::int128 value : negative_values) {
523 EXPECT_EQ(absl::uint128(-value), -absl::uint128(value));
524
525 absl::uint128 assigned_value;
526 assigned_value = value;
527 EXPECT_EQ(absl::uint128(-value), -assigned_value);
528 }
529 }
530
531 template <typename T>
532 class Int128IntegerTraitsTest : public ::testing::Test {};
533
534 TYPED_TEST_SUITE(Int128IntegerTraitsTest, IntegerTypes);
535
TYPED_TEST(Int128IntegerTraitsTest,ConstructAssignTest)536 TYPED_TEST(Int128IntegerTraitsTest, ConstructAssignTest) {
537 static_assert(std::is_constructible<absl::int128, TypeParam>::value,
538 "absl::int128 must be constructible from TypeParam");
539 static_assert(std::is_assignable<absl::int128&, TypeParam>::value,
540 "absl::int128 must be assignable from TypeParam");
541 static_assert(!std::is_assignable<TypeParam&, absl::int128>::value,
542 "TypeParam must not be assignable from absl::int128");
543 }
544
545 template <typename T>
546 class Int128FloatTraitsTest : public ::testing::Test {};
547
548 TYPED_TEST_SUITE(Int128FloatTraitsTest, FloatingPointTypes);
549
TYPED_TEST(Int128FloatTraitsTest,ConstructAssignTest)550 TYPED_TEST(Int128FloatTraitsTest, ConstructAssignTest) {
551 static_assert(std::is_constructible<absl::int128, TypeParam>::value,
552 "absl::int128 must be constructible from TypeParam");
553 static_assert(!std::is_assignable<absl::int128&, TypeParam>::value,
554 "absl::int128 must not be assignable from TypeParam");
555 static_assert(!std::is_assignable<TypeParam&, absl::int128>::value,
556 "TypeParam must not be assignable from absl::int128");
557 }
558
559 #ifdef ABSL_HAVE_INTRINSIC_INT128
560 // These type traits done separately as TYPED_TEST requires typeinfo, and not
561 // all platforms have this for __int128 even though they define the type.
TEST(Int128,IntrinsicTypeTraitsTest)562 TEST(Int128, IntrinsicTypeTraitsTest) {
563 static_assert(std::is_constructible<absl::int128, __int128>::value,
564 "absl::int128 must be constructible from __int128");
565 static_assert(std::is_assignable<absl::int128&, __int128>::value,
566 "absl::int128 must be assignable from __int128");
567 static_assert(!std::is_assignable<__int128&, absl::int128>::value,
568 "__int128 must not be assignable from absl::int128");
569
570 static_assert(std::is_constructible<absl::int128, unsigned __int128>::value,
571 "absl::int128 must be constructible from unsigned __int128");
572 static_assert(!std::is_assignable<absl::int128&, unsigned __int128>::value,
573 "absl::int128 must be assignable from unsigned __int128");
574 static_assert(!std::is_assignable<unsigned __int128&, absl::int128>::value,
575 "unsigned __int128 must not be assignable from absl::int128");
576 }
577 #endif // ABSL_HAVE_INTRINSIC_INT128
578
TEST(Int128,TrivialTraitsTest)579 TEST(Int128, TrivialTraitsTest) {
580 static_assert(absl::is_trivially_default_constructible<absl::int128>::value,
581 "");
582 static_assert(absl::is_trivially_copy_constructible<absl::int128>::value, "");
583 static_assert(absl::is_trivially_copy_assignable<absl::int128>::value, "");
584 static_assert(std::is_trivially_destructible<absl::int128>::value, "");
585 }
586
TEST(Int128,BoolConversionTest)587 TEST(Int128, BoolConversionTest) {
588 EXPECT_FALSE(absl::int128(0));
589 for (int i = 0; i < 64; ++i) {
590 EXPECT_TRUE(absl::MakeInt128(0, uint64_t{1} << i));
591 }
592 for (int i = 0; i < 63; ++i) {
593 EXPECT_TRUE(absl::MakeInt128(int64_t{1} << i, 0));
594 }
595 EXPECT_TRUE(absl::Int128Min());
596
597 EXPECT_EQ(absl::int128(1), absl::int128(true));
598 EXPECT_EQ(absl::int128(0), absl::int128(false));
599 }
600
601 template <typename T>
602 class Int128IntegerConversionTest : public ::testing::Test {};
603
604 TYPED_TEST_SUITE(Int128IntegerConversionTest, IntegerTypes);
605
TYPED_TEST(Int128IntegerConversionTest,RoundTripTest)606 TYPED_TEST(Int128IntegerConversionTest, RoundTripTest) {
607 EXPECT_EQ(TypeParam{0}, static_cast<TypeParam>(absl::int128(0)));
608 EXPECT_EQ(std::numeric_limits<TypeParam>::min(),
609 static_cast<TypeParam>(
610 absl::int128(std::numeric_limits<TypeParam>::min())));
611 EXPECT_EQ(std::numeric_limits<TypeParam>::max(),
612 static_cast<TypeParam>(
613 absl::int128(std::numeric_limits<TypeParam>::max())));
614 }
615
616 template <typename T>
617 class Int128FloatConversionTest : public ::testing::Test {};
618
619 TYPED_TEST_SUITE(Int128FloatConversionTest, FloatingPointTypes);
620
TYPED_TEST(Int128FloatConversionTest,ConstructAndCastTest)621 TYPED_TEST(Int128FloatConversionTest, ConstructAndCastTest) {
622 // Conversions where the floating point values should be exactly the same.
623 // 0x9f5b is a randomly chosen small value.
624 for (int i = 0; i < 110; ++i) { // 110 = 126 - #bits in 0x9f5b
625 SCOPED_TRACE(::testing::Message() << "i = " << i);
626
627 TypeParam float_value = std::ldexp(static_cast<TypeParam>(0x9f5b), i);
628 absl::int128 int_value = absl::int128(0x9f5b) << i;
629
630 EXPECT_EQ(float_value, static_cast<TypeParam>(int_value));
631 EXPECT_EQ(-float_value, static_cast<TypeParam>(-int_value));
632 EXPECT_EQ(int_value, absl::int128(float_value));
633 EXPECT_EQ(-int_value, absl::int128(-float_value));
634 }
635
636 // Round trip conversions with a small sample of randomly generated uint64_t
637 // values (less than int64_t max so that value * 2^64 fits into int128).
638 uint64_t values[] = {0x6d4492c24fb86199, 0x26ead65e4cb359b5,
639 0x2c43407433ba3fd1, 0x3b574ec668df6b55,
640 0x1c750e55a29f4f0f};
641 for (uint64_t value : values) {
642 for (int i = 0; i <= 64; ++i) {
643 SCOPED_TRACE(::testing::Message()
644 << "value = " << value << "; i = " << i);
645
646 TypeParam fvalue = std::ldexp(static_cast<TypeParam>(value), i);
647 EXPECT_DOUBLE_EQ(fvalue, static_cast<TypeParam>(absl::int128(fvalue)));
648 EXPECT_DOUBLE_EQ(-fvalue, static_cast<TypeParam>(-absl::int128(fvalue)));
649 EXPECT_DOUBLE_EQ(-fvalue, static_cast<TypeParam>(absl::int128(-fvalue)));
650 EXPECT_DOUBLE_EQ(fvalue, static_cast<TypeParam>(-absl::int128(-fvalue)));
651 }
652 }
653
654 // Round trip conversions with a small sample of random large positive values.
655 absl::int128 large_values[] = {
656 absl::MakeInt128(0x5b0640d96c7b3d9f, 0xb7a7189e51d18622),
657 absl::MakeInt128(0x34bed042c6f65270, 0x73b236570669a089),
658 absl::MakeInt128(0x43deba9e6da12724, 0xf7f0f83da686797d),
659 absl::MakeInt128(0x71e8d383be4e5589, 0x75c3f96fb00752b6)};
660 for (absl::int128 value : large_values) {
661 // Make value have as many significant bits as can be represented by
662 // the mantissa, also making sure the highest and lowest bit in the range
663 // are set.
664 value >>= (127 - std::numeric_limits<TypeParam>::digits);
665 value |= absl::int128(1) << (std::numeric_limits<TypeParam>::digits - 1);
666 value |= 1;
667 for (int i = 0; i < 127 - std::numeric_limits<TypeParam>::digits; ++i) {
668 absl::int128 int_value = value << i;
669 EXPECT_EQ(int_value,
670 static_cast<absl::int128>(static_cast<TypeParam>(int_value)));
671 EXPECT_EQ(-int_value,
672 static_cast<absl::int128>(static_cast<TypeParam>(-int_value)));
673 }
674 }
675
676 // Small sample of checks that rounding is toward zero
677 EXPECT_EQ(0, absl::int128(TypeParam(0.1)));
678 EXPECT_EQ(17, absl::int128(TypeParam(17.8)));
679 EXPECT_EQ(0, absl::int128(TypeParam(-0.8)));
680 EXPECT_EQ(-53, absl::int128(TypeParam(-53.1)));
681 EXPECT_EQ(0, absl::int128(TypeParam(0.5)));
682 EXPECT_EQ(0, absl::int128(TypeParam(-0.5)));
683 TypeParam just_lt_one = std::nexttoward(TypeParam(1), TypeParam(0));
684 EXPECT_EQ(0, absl::int128(just_lt_one));
685 TypeParam just_gt_minus_one = std::nexttoward(TypeParam(-1), TypeParam(0));
686 EXPECT_EQ(0, absl::int128(just_gt_minus_one));
687
688 // Check limits
689 EXPECT_DOUBLE_EQ(std::ldexp(static_cast<TypeParam>(1), 127),
690 static_cast<TypeParam>(absl::Int128Max()));
691 EXPECT_DOUBLE_EQ(-std::ldexp(static_cast<TypeParam>(1), 127),
692 static_cast<TypeParam>(absl::Int128Min()));
693 }
694
TEST(Int128,FactoryTest)695 TEST(Int128, FactoryTest) {
696 EXPECT_EQ(absl::int128(-1), absl::MakeInt128(-1, -1));
697 EXPECT_EQ(absl::int128(-31), absl::MakeInt128(-1, -31));
698 EXPECT_EQ(absl::int128(std::numeric_limits<int64_t>::min()),
699 absl::MakeInt128(-1, std::numeric_limits<int64_t>::min()));
700 EXPECT_EQ(absl::int128(0), absl::MakeInt128(0, 0));
701 EXPECT_EQ(absl::int128(1), absl::MakeInt128(0, 1));
702 EXPECT_EQ(absl::int128(std::numeric_limits<int64_t>::max()),
703 absl::MakeInt128(0, std::numeric_limits<int64_t>::max()));
704 }
705
TEST(Int128,HighLowTest)706 TEST(Int128, HighLowTest) {
707 struct HighLowPair {
708 int64_t high;
709 uint64_t low;
710 };
711 HighLowPair values[]{{0, 0}, {0, 1}, {1, 0}, {123, 456}, {-654, 321}};
712 for (const HighLowPair& pair : values) {
713 absl::int128 value = absl::MakeInt128(pair.high, pair.low);
714 EXPECT_EQ(pair.low, absl::Int128Low64(value));
715 EXPECT_EQ(pair.high, absl::Int128High64(value));
716 }
717 }
718
TEST(Int128,LimitsTest)719 TEST(Int128, LimitsTest) {
720 EXPECT_EQ(absl::MakeInt128(0x7fffffffffffffff, 0xffffffffffffffff),
721 absl::Int128Max());
722 EXPECT_EQ(absl::Int128Max(), ~absl::Int128Min());
723 }
724
725 #if defined(ABSL_HAVE_INTRINSIC_INT128)
TEST(Int128,IntrinsicConversionTest)726 TEST(Int128, IntrinsicConversionTest) {
727 __int128 intrinsic =
728 (static_cast<__int128>(0x3a5b76c209de76f6) << 64) + 0x1f25e1d63a2b46c5;
729 absl::int128 custom =
730 absl::MakeInt128(0x3a5b76c209de76f6, 0x1f25e1d63a2b46c5);
731
732 EXPECT_EQ(custom, absl::int128(intrinsic));
733 EXPECT_EQ(intrinsic, static_cast<__int128>(custom));
734 }
735 #endif // ABSL_HAVE_INTRINSIC_INT128
736
TEST(Int128,ConstexprTest)737 TEST(Int128, ConstexprTest) {
738 constexpr absl::int128 zero = absl::int128();
739 constexpr absl::int128 one = 1;
740 constexpr absl::int128 minus_two = -2;
741 constexpr absl::int128 min = absl::Int128Min();
742 constexpr absl::int128 max = absl::Int128Max();
743 EXPECT_EQ(zero, absl::int128(0));
744 EXPECT_EQ(one, absl::int128(1));
745 EXPECT_EQ(minus_two, absl::MakeInt128(-1, -2));
746 EXPECT_GT(max, one);
747 EXPECT_LT(min, minus_two);
748 }
749
TEST(Int128,ComparisonTest)750 TEST(Int128, ComparisonTest) {
751 struct TestCase {
752 absl::int128 smaller;
753 absl::int128 larger;
754 };
755 TestCase cases[] = {
756 {absl::int128(0), absl::int128(123)},
757 {absl::MakeInt128(-12, 34), absl::MakeInt128(12, 34)},
758 {absl::MakeInt128(1, 1000), absl::MakeInt128(1000, 1)},
759 {absl::MakeInt128(-1000, 1000), absl::MakeInt128(-1, 1)},
760 };
761 for (const TestCase& pair : cases) {
762 SCOPED_TRACE(::testing::Message() << "pair.smaller = " << pair.smaller
763 << "; pair.larger = " << pair.larger);
764
765 EXPECT_TRUE(pair.smaller == pair.smaller); // NOLINT(readability/check)
766 EXPECT_TRUE(pair.larger == pair.larger); // NOLINT(readability/check)
767 EXPECT_FALSE(pair.smaller == pair.larger); // NOLINT(readability/check)
768
769 EXPECT_TRUE(pair.smaller != pair.larger); // NOLINT(readability/check)
770 EXPECT_FALSE(pair.smaller != pair.smaller); // NOLINT(readability/check)
771 EXPECT_FALSE(pair.larger != pair.larger); // NOLINT(readability/check)
772
773 EXPECT_TRUE(pair.smaller < pair.larger); // NOLINT(readability/check)
774 EXPECT_FALSE(pair.larger < pair.smaller); // NOLINT(readability/check)
775
776 EXPECT_TRUE(pair.larger > pair.smaller); // NOLINT(readability/check)
777 EXPECT_FALSE(pair.smaller > pair.larger); // NOLINT(readability/check)
778
779 EXPECT_TRUE(pair.smaller <= pair.larger); // NOLINT(readability/check)
780 EXPECT_FALSE(pair.larger <= pair.smaller); // NOLINT(readability/check)
781 EXPECT_TRUE(pair.smaller <= pair.smaller); // NOLINT(readability/check)
782 EXPECT_TRUE(pair.larger <= pair.larger); // NOLINT(readability/check)
783
784 EXPECT_TRUE(pair.larger >= pair.smaller); // NOLINT(readability/check)
785 EXPECT_FALSE(pair.smaller >= pair.larger); // NOLINT(readability/check)
786 EXPECT_TRUE(pair.smaller >= pair.smaller); // NOLINT(readability/check)
787 EXPECT_TRUE(pair.larger >= pair.larger); // NOLINT(readability/check)
788
789 #ifdef __cpp_impl_three_way_comparison
790 EXPECT_EQ(pair.smaller <=> pair.larger, absl::strong_ordering::less);
791 EXPECT_EQ(pair.larger <=> pair.smaller, absl::strong_ordering::greater);
792 EXPECT_EQ(pair.smaller <=> pair.smaller, absl::strong_ordering::equal);
793 EXPECT_EQ(pair.larger <=> pair.larger, absl::strong_ordering::equal);
794 #endif
795 }
796 }
797
TEST(Int128,UnaryPlusTest)798 TEST(Int128, UnaryPlusTest) {
799 int64_t values64[] = {0, 1, 12345, 0x4000000000000000,
800 std::numeric_limits<int64_t>::max()};
801 for (int64_t value : values64) {
802 SCOPED_TRACE(::testing::Message() << "value = " << value);
803
804 EXPECT_EQ(absl::int128(value), +absl::int128(value));
805 EXPECT_EQ(absl::int128(-value), +absl::int128(-value));
806 EXPECT_EQ(absl::MakeInt128(value, 0), +absl::MakeInt128(value, 0));
807 EXPECT_EQ(absl::MakeInt128(-value, 0), +absl::MakeInt128(-value, 0));
808 }
809 }
810
TEST(Int128,UnaryNegationTest)811 TEST(Int128, UnaryNegationTest) {
812 int64_t values64[] = {0, 1, 12345, 0x4000000000000000,
813 std::numeric_limits<int64_t>::max()};
814 for (int64_t value : values64) {
815 SCOPED_TRACE(::testing::Message() << "value = " << value);
816
817 EXPECT_EQ(absl::int128(-value), -absl::int128(value));
818 EXPECT_EQ(absl::int128(value), -absl::int128(-value));
819 EXPECT_EQ(absl::MakeInt128(-value, 0), -absl::MakeInt128(value, 0));
820 EXPECT_EQ(absl::MakeInt128(value, 0), -absl::MakeInt128(-value, 0));
821 }
822 }
823
TEST(Int128,LogicalNotTest)824 TEST(Int128, LogicalNotTest) {
825 EXPECT_TRUE(!absl::int128(0));
826 for (int i = 0; i < 64; ++i) {
827 EXPECT_FALSE(!absl::MakeInt128(0, uint64_t{1} << i));
828 }
829 for (int i = 0; i < 63; ++i) {
830 EXPECT_FALSE(!absl::MakeInt128(int64_t{1} << i, 0));
831 }
832 }
833
TEST(Int128,AdditionSubtractionTest)834 TEST(Int128, AdditionSubtractionTest) {
835 // 64 bit pairs that will not cause overflow / underflow. These test negative
836 // carry; positive carry must be checked separately.
837 std::pair<int64_t, int64_t> cases[]{
838 {0, 0}, // 0, 0
839 {0, 2945781290834}, // 0, +
840 {1908357619234, 0}, // +, 0
841 {0, -1204895918245}, // 0, -
842 {-2957928523560, 0}, // -, 0
843 {89023982312461, 98346012567134}, // +, +
844 {-63454234568239, -23456235230773}, // -, -
845 {98263457263502, -21428561935925}, // +, -
846 {-88235237438467, 15923659234573}, // -, +
847 };
848 for (const auto& pair : cases) {
849 SCOPED_TRACE(::testing::Message()
850 << "pair = {" << pair.first << ", " << pair.second << '}');
851
852 EXPECT_EQ(absl::int128(pair.first + pair.second),
853 absl::int128(pair.first) + absl::int128(pair.second));
854 EXPECT_EQ(absl::int128(pair.second + pair.first),
855 absl::int128(pair.second) += absl::int128(pair.first));
856
857 EXPECT_EQ(absl::int128(pair.first - pair.second),
858 absl::int128(pair.first) - absl::int128(pair.second));
859 EXPECT_EQ(absl::int128(pair.second - pair.first),
860 absl::int128(pair.second) -= absl::int128(pair.first));
861
862 EXPECT_EQ(
863 absl::MakeInt128(pair.second + pair.first, 0),
864 absl::MakeInt128(pair.second, 0) + absl::MakeInt128(pair.first, 0));
865 EXPECT_EQ(
866 absl::MakeInt128(pair.first + pair.second, 0),
867 absl::MakeInt128(pair.first, 0) += absl::MakeInt128(pair.second, 0));
868
869 EXPECT_EQ(
870 absl::MakeInt128(pair.second - pair.first, 0),
871 absl::MakeInt128(pair.second, 0) - absl::MakeInt128(pair.first, 0));
872 EXPECT_EQ(
873 absl::MakeInt128(pair.first - pair.second, 0),
874 absl::MakeInt128(pair.first, 0) -= absl::MakeInt128(pair.second, 0));
875 }
876
877 // check positive carry
878 EXPECT_EQ(absl::MakeInt128(31, 0),
879 absl::MakeInt128(20, 1) +
880 absl::MakeInt128(10, std::numeric_limits<uint64_t>::max()));
881 }
882
TEST(Int128,IncrementDecrementTest)883 TEST(Int128, IncrementDecrementTest) {
884 absl::int128 value = 0;
885 EXPECT_EQ(0, value++);
886 EXPECT_EQ(1, value);
887 EXPECT_EQ(1, value--);
888 EXPECT_EQ(0, value);
889 EXPECT_EQ(-1, --value);
890 EXPECT_EQ(-1, value);
891 EXPECT_EQ(0, ++value);
892 EXPECT_EQ(0, value);
893 }
894
TEST(Int128,MultiplicationTest)895 TEST(Int128, MultiplicationTest) {
896 // 1 bit x 1 bit, and negative combinations
897 for (int i = 0; i < 64; ++i) {
898 for (int j = 0; j < 127 - i; ++j) {
899 SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j);
900 absl::int128 a = absl::int128(1) << i;
901 absl::int128 b = absl::int128(1) << j;
902 absl::int128 c = absl::int128(1) << (i + j);
903
904 EXPECT_EQ(c, a * b);
905 EXPECT_EQ(-c, -a * b);
906 EXPECT_EQ(-c, a * -b);
907 EXPECT_EQ(c, -a * -b);
908
909 EXPECT_EQ(c, absl::int128(a) *= b);
910 EXPECT_EQ(-c, absl::int128(-a) *= b);
911 EXPECT_EQ(-c, absl::int128(a) *= -b);
912 EXPECT_EQ(c, absl::int128(-a) *= -b);
913 }
914 }
915
916 // Pairs of random values that will not overflow signed 64-bit multiplication
917 std::pair<int64_t, int64_t> small_values[] = {
918 {0x5e61, 0xf29f79ca14b4}, // +, +
919 {0x3e033b, -0x612c0ee549}, // +, -
920 {-0x052ce7e8, 0x7c728f0f}, // -, +
921 {-0x3af7054626, -0xfb1e1d}, // -, -
922 };
923 for (const std::pair<int64_t, int64_t>& pair : small_values) {
924 SCOPED_TRACE(::testing::Message()
925 << "pair = {" << pair.first << ", " << pair.second << '}');
926
927 EXPECT_EQ(absl::int128(pair.first * pair.second),
928 absl::int128(pair.first) * absl::int128(pair.second));
929 EXPECT_EQ(absl::int128(pair.first * pair.second),
930 absl::int128(pair.first) *= absl::int128(pair.second));
931
932 EXPECT_EQ(absl::MakeInt128(pair.first * pair.second, 0),
933 absl::MakeInt128(pair.first, 0) * absl::int128(pair.second));
934 EXPECT_EQ(absl::MakeInt128(pair.first * pair.second, 0),
935 absl::MakeInt128(pair.first, 0) *= absl::int128(pair.second));
936 }
937
938 // Pairs of positive random values that will not overflow 64-bit
939 // multiplication and can be left shifted by 32 without overflow
940 std::pair<int64_t, int64_t> small_values2[] = {
941 {0x1bb0a110, 0x31487671},
942 {0x4792784e, 0x28add7d7},
943 {0x7b66553a, 0x11dff8ef},
944 };
945 for (const std::pair<int64_t, int64_t>& pair : small_values2) {
946 SCOPED_TRACE(::testing::Message()
947 << "pair = {" << pair.first << ", " << pair.second << '}');
948
949 absl::int128 a = absl::int128(pair.first << 32);
950 absl::int128 b = absl::int128(pair.second << 32);
951 absl::int128 c = absl::MakeInt128(pair.first * pair.second, 0);
952
953 EXPECT_EQ(c, a * b);
954 EXPECT_EQ(-c, -a * b);
955 EXPECT_EQ(-c, a * -b);
956 EXPECT_EQ(c, -a * -b);
957
958 EXPECT_EQ(c, absl::int128(a) *= b);
959 EXPECT_EQ(-c, absl::int128(-a) *= b);
960 EXPECT_EQ(-c, absl::int128(a) *= -b);
961 EXPECT_EQ(c, absl::int128(-a) *= -b);
962 }
963
964 // check 0, 1, and -1 behavior with large values
965 absl::int128 large_values[] = {
966 {absl::MakeInt128(0xd66f061af02d0408, 0x727d2846cb475b53)},
967 {absl::MakeInt128(0x27b8d5ed6104452d, 0x03f8a33b0ee1df4f)},
968 {-absl::MakeInt128(0x621b6626b9e8d042, 0x27311ac99df00938)},
969 {-absl::MakeInt128(0x34e0656f1e95fb60, 0x4281cfd731257a47)},
970 };
971 for (absl::int128 value : large_values) {
972 EXPECT_EQ(0, 0 * value);
973 EXPECT_EQ(0, value * 0);
974 EXPECT_EQ(0, absl::int128(0) *= value);
975 EXPECT_EQ(0, value *= 0);
976
977 EXPECT_EQ(value, 1 * value);
978 EXPECT_EQ(value, value * 1);
979 EXPECT_EQ(value, absl::int128(1) *= value);
980 EXPECT_EQ(value, value *= 1);
981
982 EXPECT_EQ(-value, -1 * value);
983 EXPECT_EQ(-value, value * -1);
984 EXPECT_EQ(-value, absl::int128(-1) *= value);
985 EXPECT_EQ(-value, value *= -1);
986 }
987
988 // Manually calculated random large value cases
989 EXPECT_EQ(absl::MakeInt128(0xcd0efd3442219bb, 0xde47c05bcd9df6e1),
990 absl::MakeInt128(0x7c6448, 0x3bc4285c47a9d253) * 0x1a6037537b);
991 EXPECT_EQ(-absl::MakeInt128(0x1f8f149850b1e5e6, 0x1e50d6b52d272c3e),
992 -absl::MakeInt128(0x23, 0x2e68a513ca1b8859) * 0xe5a434cd14866e);
993 EXPECT_EQ(-absl::MakeInt128(0x55cae732029d1fce, 0xca6474b6423263e4),
994 0xa9b98a8ddf66bc * -absl::MakeInt128(0x81, 0x672e58231e2469d7));
995 EXPECT_EQ(absl::MakeInt128(0x19c8b7620b507dc4, 0xfec042b71a5f29a4),
996 -0x3e39341147 * -absl::MakeInt128(0x6a14b2, 0x5ed34cca42327b3c));
997
998 EXPECT_EQ(absl::MakeInt128(0xcd0efd3442219bb, 0xde47c05bcd9df6e1),
999 absl::MakeInt128(0x7c6448, 0x3bc4285c47a9d253) *= 0x1a6037537b);
1000 EXPECT_EQ(-absl::MakeInt128(0x1f8f149850b1e5e6, 0x1e50d6b52d272c3e),
1001 -absl::MakeInt128(0x23, 0x2e68a513ca1b8859) *= 0xe5a434cd14866e);
1002 EXPECT_EQ(-absl::MakeInt128(0x55cae732029d1fce, 0xca6474b6423263e4),
1003 absl::int128(0xa9b98a8ddf66bc) *=
1004 -absl::MakeInt128(0x81, 0x672e58231e2469d7));
1005 EXPECT_EQ(absl::MakeInt128(0x19c8b7620b507dc4, 0xfec042b71a5f29a4),
1006 absl::int128(-0x3e39341147) *=
1007 -absl::MakeInt128(0x6a14b2, 0x5ed34cca42327b3c));
1008 }
1009
TEST(Int128,DivisionAndModuloTest)1010 TEST(Int128, DivisionAndModuloTest) {
1011 // Check against 64 bit division and modulo operators with a sample of
1012 // randomly generated pairs.
1013 std::pair<int64_t, int64_t> small_pairs[] = {
1014 {0x15f2a64138, 0x67da05}, {0x5e56d194af43045f, 0xcf1543fb99},
1015 {0x15e61ed052036a, -0xc8e6}, {0x88125a341e85, -0xd23fb77683},
1016 {-0xc06e20, 0x5a}, {-0x4f100219aea3e85d, 0xdcc56cb4efe993},
1017 {-0x168d629105, -0xa7}, {-0x7b44e92f03ab2375, -0x6516},
1018 };
1019 for (const std::pair<int64_t, int64_t>& pair : small_pairs) {
1020 SCOPED_TRACE(::testing::Message()
1021 << "pair = {" << pair.first << ", " << pair.second << '}');
1022
1023 absl::int128 dividend = pair.first;
1024 absl::int128 divisor = pair.second;
1025 int64_t quotient = pair.first / pair.second;
1026 int64_t remainder = pair.first % pair.second;
1027
1028 EXPECT_EQ(quotient, dividend / divisor);
1029 EXPECT_EQ(quotient, absl::int128(dividend) /= divisor);
1030 EXPECT_EQ(remainder, dividend % divisor);
1031 EXPECT_EQ(remainder, absl::int128(dividend) %= divisor);
1032 }
1033
1034 // Test behavior with 0, 1, and -1 with a sample of randomly generated large
1035 // values.
1036 absl::int128 values[] = {
1037 absl::MakeInt128(0x63d26ee688a962b2, 0x9e1411abda5c1d70),
1038 absl::MakeInt128(0x152f385159d6f986, 0xbf8d48ef63da395d),
1039 -absl::MakeInt128(0x3098d7567030038c, 0x14e7a8a098dc2164),
1040 -absl::MakeInt128(0x49a037aca35c809f, 0xa6a87525480ef330),
1041 };
1042 for (absl::int128 value : values) {
1043 SCOPED_TRACE(::testing::Message() << "value = " << value);
1044
1045 EXPECT_EQ(0, 0 / value);
1046 EXPECT_EQ(0, absl::int128(0) /= value);
1047 EXPECT_EQ(0, 0 % value);
1048 EXPECT_EQ(0, absl::int128(0) %= value);
1049
1050 EXPECT_EQ(value, value / 1);
1051 EXPECT_EQ(value, absl::int128(value) /= 1);
1052 EXPECT_EQ(0, value % 1);
1053 EXPECT_EQ(0, absl::int128(value) %= 1);
1054
1055 EXPECT_EQ(-value, value / -1);
1056 EXPECT_EQ(-value, absl::int128(value) /= -1);
1057 EXPECT_EQ(0, value % -1);
1058 EXPECT_EQ(0, absl::int128(value) %= -1);
1059 }
1060
1061 // Min and max values
1062 EXPECT_EQ(0, absl::Int128Max() / absl::Int128Min());
1063 EXPECT_EQ(absl::Int128Max(), absl::Int128Max() % absl::Int128Min());
1064 EXPECT_EQ(-1, absl::Int128Min() / absl::Int128Max());
1065 EXPECT_EQ(-1, absl::Int128Min() % absl::Int128Max());
1066
1067 // Power of two division and modulo of random large dividends
1068 absl::int128 positive_values[] = {
1069 absl::MakeInt128(0x21e1a1cc69574620, 0xe7ac447fab2fc869),
1070 absl::MakeInt128(0x32c2ff3ab89e66e8, 0x03379a613fd1ce74),
1071 absl::MakeInt128(0x6f32ca786184dcaf, 0x046f9c9ecb3a9ce1),
1072 absl::MakeInt128(0x1aeb469dd990e0ee, 0xda2740f243cd37eb),
1073 };
1074 for (absl::int128 value : positive_values) {
1075 for (int i = 0; i < 127; ++i) {
1076 SCOPED_TRACE(::testing::Message()
1077 << "value = " << value << "; i = " << i);
1078 absl::int128 power_of_two = absl::int128(1) << i;
1079
1080 EXPECT_EQ(value >> i, value / power_of_two);
1081 EXPECT_EQ(value >> i, absl::int128(value) /= power_of_two);
1082 EXPECT_EQ(value & (power_of_two - 1), value % power_of_two);
1083 EXPECT_EQ(value & (power_of_two - 1),
1084 absl::int128(value) %= power_of_two);
1085 }
1086 }
1087
1088 // Manually calculated cases with random large dividends
1089 struct DivisionModCase {
1090 absl::int128 dividend;
1091 absl::int128 divisor;
1092 absl::int128 quotient;
1093 absl::int128 remainder;
1094 };
1095 DivisionModCase manual_cases[] = {
1096 {absl::MakeInt128(0x6ada48d489007966, 0x3c9c5c98150d5d69),
1097 absl::MakeInt128(0x8bc308fb, 0x8cb9cc9a3b803344), 0xc3b87e08,
1098 absl::MakeInt128(0x1b7db5e1, 0xd9eca34b7af04b49)},
1099 {absl::MakeInt128(0xd6946511b5b, 0x4886c5c96546bf5f),
1100 -absl::MakeInt128(0x263b, 0xfd516279efcfe2dc), -0x59cbabf0,
1101 absl::MakeInt128(0x622, 0xf462909155651d1f)},
1102 {-absl::MakeInt128(0x33db734f9e8d1399, 0x8447ac92482bca4d), 0x37495078240,
1103 -absl::MakeInt128(0xf01f1, 0xbc0368bf9a77eae8), -0x21a508f404d},
1104 {-absl::MakeInt128(0x13f837b409a07e7d, 0x7fc8e248a7d73560), -0x1b9f,
1105 absl::MakeInt128(0xb9157556d724, 0xb14f635714d7563e), -0x1ade},
1106 };
1107 for (const DivisionModCase test_case : manual_cases) {
1108 EXPECT_EQ(test_case.quotient, test_case.dividend / test_case.divisor);
1109 EXPECT_EQ(test_case.quotient,
1110 absl::int128(test_case.dividend) /= test_case.divisor);
1111 EXPECT_EQ(test_case.remainder, test_case.dividend % test_case.divisor);
1112 EXPECT_EQ(test_case.remainder,
1113 absl::int128(test_case.dividend) %= test_case.divisor);
1114 }
1115 }
1116
TEST(Int128,BitwiseLogicTest)1117 TEST(Int128, BitwiseLogicTest) {
1118 EXPECT_EQ(absl::int128(-1), ~absl::int128(0));
1119
1120 absl::int128 values[]{
1121 0, -1, 0xde400bee05c3ff6b, absl::MakeInt128(0x7f32178dd81d634a, 0),
1122 absl::MakeInt128(0xaf539057055613a9, 0x7d104d7d946c2e4d)};
1123 for (absl::int128 value : values) {
1124 EXPECT_EQ(value, ~~value);
1125
1126 EXPECT_EQ(value, value | value);
1127 EXPECT_EQ(value, value & value);
1128 EXPECT_EQ(0, value ^ value);
1129
1130 EXPECT_EQ(value, absl::int128(value) |= value);
1131 EXPECT_EQ(value, absl::int128(value) &= value);
1132 EXPECT_EQ(0, absl::int128(value) ^= value);
1133
1134 EXPECT_EQ(value, value | 0);
1135 EXPECT_EQ(0, value & 0);
1136 EXPECT_EQ(value, value ^ 0);
1137
1138 EXPECT_EQ(absl::int128(-1), value | absl::int128(-1));
1139 EXPECT_EQ(value, value & absl::int128(-1));
1140 EXPECT_EQ(~value, value ^ absl::int128(-1));
1141 }
1142
1143 // small sample of randomly generated int64_t's
1144 std::pair<int64_t, int64_t> pairs64[]{
1145 {0x7f86797f5e991af4, 0x1ee30494fb007c97},
1146 {0x0b278282bacf01af, 0x58780e0a57a49e86},
1147 {0x059f266ccb93a666, 0x3d5b731bae9286f5},
1148 {0x63c0c4820f12108c, 0x58166713c12e1c3a},
1149 {0x381488bb2ed2a66e, 0x2220a3eb76a3698c},
1150 {0x2a0a0dfb81e06f21, 0x4b60585927f5523c},
1151 {0x555b1c3a03698537, 0x25478cd19d8e53cb},
1152 {0x4750f6f27d779225, 0x16397553c6ff05fc},
1153 };
1154 for (const std::pair<int64_t, int64_t>& pair : pairs64) {
1155 SCOPED_TRACE(::testing::Message()
1156 << "pair = {" << pair.first << ", " << pair.second << '}');
1157
1158 EXPECT_EQ(absl::MakeInt128(~pair.first, ~pair.second),
1159 ~absl::MakeInt128(pair.first, pair.second));
1160
1161 EXPECT_EQ(absl::int128(pair.first & pair.second),
1162 absl::int128(pair.first) & absl::int128(pair.second));
1163 EXPECT_EQ(absl::int128(pair.first | pair.second),
1164 absl::int128(pair.first) | absl::int128(pair.second));
1165 EXPECT_EQ(absl::int128(pair.first ^ pair.second),
1166 absl::int128(pair.first) ^ absl::int128(pair.second));
1167
1168 EXPECT_EQ(absl::int128(pair.first & pair.second),
1169 absl::int128(pair.first) &= absl::int128(pair.second));
1170 EXPECT_EQ(absl::int128(pair.first | pair.second),
1171 absl::int128(pair.first) |= absl::int128(pair.second));
1172 EXPECT_EQ(absl::int128(pair.first ^ pair.second),
1173 absl::int128(pair.first) ^= absl::int128(pair.second));
1174
1175 EXPECT_EQ(
1176 absl::MakeInt128(pair.first & pair.second, 0),
1177 absl::MakeInt128(pair.first, 0) & absl::MakeInt128(pair.second, 0));
1178 EXPECT_EQ(
1179 absl::MakeInt128(pair.first | pair.second, 0),
1180 absl::MakeInt128(pair.first, 0) | absl::MakeInt128(pair.second, 0));
1181 EXPECT_EQ(
1182 absl::MakeInt128(pair.first ^ pair.second, 0),
1183 absl::MakeInt128(pair.first, 0) ^ absl::MakeInt128(pair.second, 0));
1184
1185 EXPECT_EQ(
1186 absl::MakeInt128(pair.first & pair.second, 0),
1187 absl::MakeInt128(pair.first, 0) &= absl::MakeInt128(pair.second, 0));
1188 EXPECT_EQ(
1189 absl::MakeInt128(pair.first | pair.second, 0),
1190 absl::MakeInt128(pair.first, 0) |= absl::MakeInt128(pair.second, 0));
1191 EXPECT_EQ(
1192 absl::MakeInt128(pair.first ^ pair.second, 0),
1193 absl::MakeInt128(pair.first, 0) ^= absl::MakeInt128(pair.second, 0));
1194 }
1195 }
1196
TEST(Int128,BitwiseShiftTest)1197 TEST(Int128, BitwiseShiftTest) {
1198 for (int i = 0; i < 64; ++i) {
1199 for (int j = 0; j <= i; ++j) {
1200 // Left shift from j-th bit to i-th bit.
1201 SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j);
1202 EXPECT_EQ(uint64_t{1} << i, absl::int128(uint64_t{1} << j) << (i - j));
1203 EXPECT_EQ(uint64_t{1} << i, absl::int128(uint64_t{1} << j) <<= (i - j));
1204 }
1205 }
1206 for (int i = 0; i < 63; ++i) {
1207 for (int j = 0; j < 64; ++j) {
1208 // Left shift from j-th bit to (i + 64)-th bit.
1209 SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j);
1210 EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0),
1211 absl::int128(uint64_t{1} << j) << (i + 64 - j));
1212 EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0),
1213 absl::int128(uint64_t{1} << j) <<= (i + 64 - j));
1214 }
1215 for (int j = 0; j <= i; ++j) {
1216 // Left shift from (j + 64)-th bit to (i + 64)-th bit.
1217 SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j);
1218 EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0),
1219 absl::MakeInt128(uint64_t{1} << j, 0) << (i - j));
1220 EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0),
1221 absl::MakeInt128(uint64_t{1} << j, 0) <<= (i - j));
1222 }
1223 }
1224
1225 for (int i = 0; i < 64; ++i) {
1226 for (int j = i; j < 64; ++j) {
1227 // Right shift from j-th bit to i-th bit.
1228 SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j);
1229 EXPECT_EQ(uint64_t{1} << i, absl::int128(uint64_t{1} << j) >> (j - i));
1230 EXPECT_EQ(uint64_t{1} << i, absl::int128(uint64_t{1} << j) >>= (j - i));
1231 }
1232 for (int j = 0; j < 63; ++j) {
1233 // Right shift from (j + 64)-th bit to i-th bit.
1234 SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j);
1235 EXPECT_EQ(uint64_t{1} << i,
1236 absl::MakeInt128(uint64_t{1} << j, 0) >> (j + 64 - i));
1237 EXPECT_EQ(uint64_t{1} << i,
1238 absl::MakeInt128(uint64_t{1} << j, 0) >>= (j + 64 - i));
1239 }
1240 }
1241 for (int i = 0; i < 63; ++i) {
1242 for (int j = i; j < 63; ++j) {
1243 // Right shift from (j + 64)-th bit to (i + 64)-th bit.
1244 SCOPED_TRACE(::testing::Message() << "i = " << i << "; j = " << j);
1245 EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0),
1246 absl::MakeInt128(uint64_t{1} << j, 0) >> (j - i));
1247 EXPECT_EQ(absl::MakeInt128(uint64_t{1} << i, 0),
1248 absl::MakeInt128(uint64_t{1} << j, 0) >>= (j - i));
1249 }
1250 }
1251
1252 // Manually calculated cases with shift count for positive (val1) and negative
1253 // (val2) values
1254 absl::int128 val1 = MAKE_INT128(0x123456789abcdef0, 0x123456789abcdef0);
1255 absl::int128 val2 = MAKE_INT128(0xfedcba0987654321, 0xfedcba0987654321);
1256
1257 EXPECT_EQ(val1 << 63, MAKE_INT128(0x91a2b3c4d5e6f78, 0x0));
1258 EXPECT_EQ(val1 << 64, MAKE_INT128(0x123456789abcdef0, 0x0));
1259 EXPECT_EQ(val2 << 63, MAKE_INT128(0xff6e5d04c3b2a190, 0x8000000000000000));
1260 EXPECT_EQ(val2 << 64, MAKE_INT128(0xfedcba0987654321, 0x0));
1261
1262 EXPECT_EQ(val1 << 126, MAKE_INT128(0x0, 0x0));
1263 EXPECT_EQ(val2 << 126, MAKE_INT128(0x4000000000000000, 0x0));
1264
1265 EXPECT_EQ(val1 >> 63, MAKE_INT128(0x0, 0x2468acf13579bde0));
1266 EXPECT_EQ(val1 >> 64, MAKE_INT128(0x0, 0x123456789abcdef0));
1267 EXPECT_EQ(val2 >> 63, MAKE_INT128(0xffffffffffffffff, 0xfdb974130eca8643));
1268 EXPECT_EQ(val2 >> 64, MAKE_INT128(0xffffffffffffffff, 0xfedcba0987654321));
1269
1270 EXPECT_EQ(val1 >> 126, MAKE_INT128(0x0, 0x0));
1271 EXPECT_EQ(val2 >> 126, MAKE_INT128(0xffffffffffffffff, 0xffffffffffffffff));
1272 }
1273
TEST(Int128,NumericLimitsTest)1274 TEST(Int128, NumericLimitsTest) {
1275 static_assert(std::numeric_limits<absl::int128>::is_specialized, "");
1276 static_assert(std::numeric_limits<absl::int128>::is_signed, "");
1277 static_assert(std::numeric_limits<absl::int128>::is_integer, "");
1278 EXPECT_EQ(static_cast<int>(127 * std::log10(2)),
1279 std::numeric_limits<absl::int128>::digits10);
1280 EXPECT_EQ(absl::Int128Min(), std::numeric_limits<absl::int128>::min());
1281 EXPECT_EQ(absl::Int128Min(), std::numeric_limits<absl::int128>::lowest());
1282 EXPECT_EQ(absl::Int128Max(), std::numeric_limits<absl::int128>::max());
1283 }
1284
1285 } // namespace
1286