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