xref: /llvm-project/libc/test/src/__support/big_int_test.cpp (revision 88f0dc48d6f46e1677dc679ae649e9b291140b13)
1 //===-- Unittests for the UInt integer class ------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "src/__support/CPP/optional.h"
10 #include "src/__support/big_int.h"
11 #include "src/__support/integer_literals.h"        // parse_unsigned_bigint
12 #include "src/__support/macros/config.h"
13 #include "src/__support/macros/properties/types.h" // LIBC_TYPES_HAS_INT128
14 
15 #include "hdr/math_macros.h" // HUGE_VALF, HUGE_VALF
16 #include "test/UnitTest/Test.h"
17 
18 namespace LIBC_NAMESPACE_DECL {
19 
20 enum Value { ZERO, ONE, TWO, MIN, MAX };
21 
22 template <typename T> auto create(Value value) {
23   switch (value) {
24   case ZERO:
25     return T(0);
26   case ONE:
27     return T(1);
28   case TWO:
29     return T(2);
30   case MIN:
31     return T::min();
32   case MAX:
33     return T::max();
34   }
35   __builtin_unreachable();
36 }
37 
38 using Types = testing::TypeList< //
39 #ifdef LIBC_TYPES_HAS_INT64
40     BigInt<64, false, uint64_t>, // 64-bits unsigned (1 x uint64_t)
41     BigInt<64, true, uint64_t>,  // 64-bits   signed (1 x uint64_t)
42 #endif
43 #ifdef LIBC_TYPES_HAS_INT128
44     BigInt<128, false, __uint128_t>, // 128-bits unsigned (1 x __uint128_t)
45     BigInt<128, true, __uint128_t>,  // 128-bits   signed (1 x __uint128_t)
46 #endif
47     BigInt<16, false, uint16_t>, // 16-bits unsigned (1 x uint16_t)
48     BigInt<16, true, uint16_t>,  // 16-bits   signed (1 x uint16_t)
49     BigInt<64, false, uint16_t>, // 64-bits unsigned (4 x uint16_t)
50     BigInt<64, true, uint16_t>   // 64-bits   signed (4 x uint16_t)
51     >;
52 
53 #define ASSERT_SAME(A, B) ASSERT_TRUE((A) == (B))
54 
55 TYPED_TEST(LlvmLibcUIntClassTest, Additions, Types) {
56   ASSERT_SAME(create<T>(ZERO) + create<T>(ZERO), create<T>(ZERO));
57   ASSERT_SAME(create<T>(ONE) + create<T>(ZERO), create<T>(ONE));
58   ASSERT_SAME(create<T>(ZERO) + create<T>(ONE), create<T>(ONE));
59   ASSERT_SAME(create<T>(ONE) + create<T>(ONE), create<T>(TWO));
60   // 2's complement addition works for signed and unsigned types.
61   // - unsigned : 0xff + 0x01 = 0x00 (255 + 1 = 0)
62   // -   signed : 0xef + 0x01 = 0xf0 (127 + 1 = -128)
63   ASSERT_SAME(create<T>(MAX) + create<T>(ONE), create<T>(MIN));
64 }
65 
66 TYPED_TEST(LlvmLibcUIntClassTest, Subtraction, Types) {
67   ASSERT_SAME(create<T>(ZERO) - create<T>(ZERO), create<T>(ZERO));
68   ASSERT_SAME(create<T>(ONE) - create<T>(ONE), create<T>(ZERO));
69   ASSERT_SAME(create<T>(ONE) - create<T>(ZERO), create<T>(ONE));
70   // 2's complement subtraction works for signed and unsigned types.
71   // - unsigned : 0x00 - 0x01 = 0xff (   0 - 1 = 255)
72   // -   signed : 0xf0 - 0x01 = 0xef (-128 - 1 = 127)
73   ASSERT_SAME(create<T>(MIN) - create<T>(ONE), create<T>(MAX));
74 }
75 
76 TYPED_TEST(LlvmLibcUIntClassTest, Multiplication, Types) {
77   ASSERT_SAME(create<T>(ZERO) * create<T>(ZERO), create<T>(ZERO));
78   ASSERT_SAME(create<T>(ZERO) * create<T>(ONE), create<T>(ZERO));
79   ASSERT_SAME(create<T>(ONE) * create<T>(ZERO), create<T>(ZERO));
80   ASSERT_SAME(create<T>(ONE) * create<T>(ONE), create<T>(ONE));
81   ASSERT_SAME(create<T>(ONE) * create<T>(TWO), create<T>(TWO));
82   ASSERT_SAME(create<T>(TWO) * create<T>(ONE), create<T>(TWO));
83   // - unsigned : 0xff x 0xff = 0x01 (mod 0xff)
84   // -   signed : 0xef x 0xef = 0x01 (mod 0xff)
85   ASSERT_SAME(create<T>(MAX) * create<T>(MAX), create<T>(ONE));
86 }
87 
88 template <typename T> void print(const char *msg, T value) {
89   testing::tlog << msg;
90   IntegerToString<T, radix::Hex> buffer(value);
91   testing::tlog << buffer.view() << "\n";
92 }
93 
94 TEST(LlvmLibcUIntClassTest, SignedAddSub) {
95   // Computations performed by https://www.wolframalpha.com/
96   using T = BigInt<128, true, uint32_t>;
97   const T a = parse_bigint<T>("1927508279017230597");
98   const T b = parse_bigint<T>("278789278723478925");
99   const T s = parse_bigint<T>("2206297557740709522");
100   // Addition
101   ASSERT_SAME(a + b, s);
102   ASSERT_SAME(b + a, s); // commutative
103   // Subtraction
104   ASSERT_SAME(a - s, -b);
105   ASSERT_SAME(s - a, b);
106 }
107 
108 TEST(LlvmLibcUIntClassTest, SignedMulDiv) {
109   // Computations performed by https://www.wolframalpha.com/
110   using T = BigInt<128, true, uint16_t>;
111   struct {
112     const char *a;
113     const char *b;
114     const char *mul;
115   } const test_cases[] = {{"-4", "3", "-12"},
116                           {"-3", "-3", "9"},
117                           {"1927508279017230597", "278789278723478925",
118                            "537368642840747885329125014794668225"}};
119   for (auto tc : test_cases) {
120     const T a = parse_bigint<T>(tc.a);
121     const T b = parse_bigint<T>(tc.b);
122     const T mul = parse_bigint<T>(tc.mul);
123     // Multiplication
124     ASSERT_SAME(a * b, mul);
125     ASSERT_SAME(b * a, mul);   // commutative
126     ASSERT_SAME(a * -b, -mul); // sign
127     ASSERT_SAME(-a * b, -mul); // sign
128     ASSERT_SAME(-a * -b, mul); // sign
129     // Division
130     ASSERT_SAME(mul / a, b);
131     ASSERT_SAME(mul / b, a);
132     ASSERT_SAME(-mul / a, -b); // sign
133     ASSERT_SAME(mul / -a, -b); // sign
134     ASSERT_SAME(-mul / -a, b); // sign
135   }
136 }
137 
138 TYPED_TEST(LlvmLibcUIntClassTest, Division, Types) {
139   ASSERT_SAME(create<T>(ZERO) / create<T>(ONE), create<T>(ZERO));
140   ASSERT_SAME(create<T>(MAX) / create<T>(ONE), create<T>(MAX));
141   ASSERT_SAME(create<T>(MAX) / create<T>(MAX), create<T>(ONE));
142   ASSERT_SAME(create<T>(ONE) / create<T>(ONE), create<T>(ONE));
143   if constexpr (T::SIGNED) {
144     // Special case found by fuzzing.
145     ASSERT_SAME(create<T>(MIN) / create<T>(MIN), create<T>(ONE));
146   }
147   // - unsigned : 0xff / 0x02 = 0x7f
148   // -   signed : 0xef / 0x02 = 0x77
149   ASSERT_SAME(create<T>(MAX) / create<T>(TWO), (create<T>(MAX) >> 1));
150 
151   using word_type = typename T::word_type;
152   const T zero_one_repeated = T::all_ones() / T(0xff);
153   const word_type pattern = word_type(~0) / word_type(0xff);
154   for (const word_type part : zero_one_repeated.val) {
155     if constexpr (T::SIGNED == false) {
156       EXPECT_EQ(part, pattern);
157     }
158   }
159 }
160 
161 TYPED_TEST(LlvmLibcUIntClassTest, is_neg, Types) {
162   EXPECT_FALSE(create<T>(ZERO).is_neg());
163   EXPECT_FALSE(create<T>(ONE).is_neg());
164   EXPECT_FALSE(create<T>(TWO).is_neg());
165   EXPECT_EQ(create<T>(MIN).is_neg(), T::SIGNED);
166   EXPECT_FALSE(create<T>(MAX).is_neg());
167 }
168 
169 TYPED_TEST(LlvmLibcUIntClassTest, Masks, Types) {
170   if constexpr (!T::SIGNED) {
171     constexpr size_t BITS = T::BITS;
172     // mask_trailing_ones
173     ASSERT_SAME((mask_trailing_ones<T, 0>()), T::zero());
174     ASSERT_SAME((mask_trailing_ones<T, 1>()), T::one());
175     ASSERT_SAME((mask_trailing_ones<T, BITS - 1>()), T::all_ones() >> 1);
176     ASSERT_SAME((mask_trailing_ones<T, BITS>()), T::all_ones());
177     // mask_leading_ones
178     ASSERT_SAME((mask_leading_ones<T, 0>()), T::zero());
179     ASSERT_SAME((mask_leading_ones<T, 1>()), T::one() << (BITS - 1));
180     ASSERT_SAME((mask_leading_ones<T, BITS - 1>()), T::all_ones() - T::one());
181     ASSERT_SAME((mask_leading_ones<T, BITS>()), T::all_ones());
182     // mask_trailing_zeros
183     ASSERT_SAME((mask_trailing_zeros<T, 0>()), T::all_ones());
184     ASSERT_SAME((mask_trailing_zeros<T, 1>()), T::all_ones() - T::one());
185     ASSERT_SAME((mask_trailing_zeros<T, BITS - 1>()), T::one() << (BITS - 1));
186     ASSERT_SAME((mask_trailing_zeros<T, BITS>()), T::zero());
187     // mask_trailing_zeros
188     ASSERT_SAME((mask_leading_zeros<T, 0>()), T::all_ones());
189     ASSERT_SAME((mask_leading_zeros<T, 1>()), T::all_ones() >> 1);
190     ASSERT_SAME((mask_leading_zeros<T, BITS - 1>()), T::one());
191     ASSERT_SAME((mask_leading_zeros<T, BITS>()), T::zero());
192   }
193 }
194 
195 TYPED_TEST(LlvmLibcUIntClassTest, CountBits, Types) {
196   if constexpr (!T::SIGNED) {
197     for (size_t i = 0; i < T::BITS; ++i) {
198       const auto l_one = T::all_ones() << i; // 0b111...000
199       const auto r_one = T::all_ones() >> i; // 0b000...111
200       const int zeros = i;
201       const int ones = T::BITS - zeros;
202       ASSERT_EQ(cpp::countr_one(r_one), ones);
203       ASSERT_EQ(cpp::countl_one(l_one), ones);
204       ASSERT_EQ(cpp::countr_zero(l_one), zeros);
205       ASSERT_EQ(cpp::countl_zero(r_one), zeros);
206     }
207   }
208 }
209 
210 using LL_UInt16 = UInt<16>;
211 using LL_UInt64 = UInt<64>;
212 // We want to test UInt<128> explicitly. So, for
213 // convenience, we use a sugar which does not conflict with the UInt128 type
214 // which can resolve to __uint128_t if the platform has it.
215 using LL_UInt128 = UInt<128>;
216 using LL_UInt192 = UInt<192>;
217 using LL_UInt256 = UInt<256>;
218 using LL_UInt320 = UInt<320>;
219 using LL_UInt512 = UInt<512>;
220 using LL_UInt1024 = UInt<1024>;
221 
222 using LL_Int128 = Int<128>;
223 using LL_Int192 = Int<192>;
224 
225 TEST(LlvmLibcUIntClassTest, BitCastToFromDouble) {
226   static_assert(cpp::is_trivially_copyable<LL_UInt64>::value);
227   static_assert(sizeof(LL_UInt64) == sizeof(double));
228   const double inf = HUGE_VAL;
229   const double max = DBL_MAX;
230   const double array[] = {0.0, 0.1, 1.0, max, inf};
231   for (double value : array) {
232     LL_UInt64 back = cpp::bit_cast<LL_UInt64>(value);
233     double forth = cpp::bit_cast<double>(back);
234     EXPECT_TRUE(value == forth);
235   }
236 }
237 
238 #ifdef LIBC_TYPES_HAS_INT128
239 TEST(LlvmLibcUIntClassTest, BitCastToFromNativeUint128) {
240   static_assert(cpp::is_trivially_copyable<LL_UInt128>::value);
241   static_assert(sizeof(LL_UInt128) == sizeof(__uint128_t));
242   const __uint128_t array[] = {0, 1, ~__uint128_t(0)};
243   for (__uint128_t value : array) {
244     LL_UInt128 back = cpp::bit_cast<LL_UInt128>(value);
245     __uint128_t forth = cpp::bit_cast<__uint128_t>(back);
246     EXPECT_TRUE(value == forth);
247   }
248 }
249 #endif // LIBC_TYPES_HAS_INT128
250 
251 #ifdef LIBC_TYPES_HAS_FLOAT128
252 TEST(LlvmLibcUIntClassTest, BitCastToFromNativeFloat128) {
253   static_assert(cpp::is_trivially_copyable<LL_UInt128>::value);
254   static_assert(sizeof(LL_UInt128) == sizeof(float128));
255   const float128 array[] = {0, 0.1, 1};
256   for (float128 value : array) {
257     LL_UInt128 back = cpp::bit_cast<LL_UInt128>(value);
258     float128 forth = cpp::bit_cast<float128>(back);
259     EXPECT_TRUE(value == forth);
260   }
261 }
262 #endif // LIBC_TYPES_HAS_FLOAT128
263 
264 #ifdef LIBC_TYPES_HAS_FLOAT16
265 TEST(LlvmLibcUIntClassTest, BitCastToFromNativeFloat16) {
266   static_assert(cpp::is_trivially_copyable<LL_UInt16>::value);
267   static_assert(sizeof(LL_UInt16) == sizeof(float16));
268   const float16 array[] = {
269       static_cast<float16>(0.0),
270       static_cast<float16>(0.1),
271       static_cast<float16>(1.0),
272   };
273   for (float16 value : array) {
274     LL_UInt16 back = cpp::bit_cast<LL_UInt16>(value);
275     float16 forth = cpp::bit_cast<float16>(back);
276     EXPECT_TRUE(value == forth);
277   }
278 }
279 #endif // LIBC_TYPES_HAS_FLOAT16
280 
281 TEST(LlvmLibcUIntClassTest, BasicInit) {
282   LL_UInt128 half_val(12345);
283   LL_UInt128 full_val({12345, 67890});
284   ASSERT_TRUE(half_val != full_val);
285 }
286 
287 TEST(LlvmLibcUIntClassTest, AdditionTests) {
288   LL_UInt128 val1(12345);
289   LL_UInt128 val2(54321);
290   LL_UInt128 result1(66666);
291   EXPECT_EQ(val1 + val2, result1);
292   EXPECT_EQ((val1 + val2), (val2 + val1)); // addition is commutative
293 
294   // Test overflow
295   LL_UInt128 val3({0xf000000000000001, 0});
296   LL_UInt128 val4({0x100000000000000f, 0});
297   LL_UInt128 result2({0x10, 0x1});
298   EXPECT_EQ(val3 + val4, result2);
299   EXPECT_EQ(val3 + val4, val4 + val3);
300 
301   // Test overflow
302   LL_UInt128 val5({0x0123456789abcdef, 0xfedcba9876543210});
303   LL_UInt128 val6({0x1111222233334444, 0xaaaabbbbccccdddd});
304   LL_UInt128 result3({0x12346789bcdf1233, 0xa987765443210fed});
305   EXPECT_EQ(val5 + val6, result3);
306   EXPECT_EQ(val5 + val6, val6 + val5);
307 
308   // Test 192-bit addition
309   LL_UInt192 val7({0x0123456789abcdef, 0xfedcba9876543210, 0xfedcba9889abcdef});
310   LL_UInt192 val8({0x1111222233334444, 0xaaaabbbbccccdddd, 0xeeeeffffeeeeffff});
311   LL_UInt192 result4(
312       {0x12346789bcdf1233, 0xa987765443210fed, 0xedcbba98789acdef});
313   EXPECT_EQ(val7 + val8, result4);
314   EXPECT_EQ(val7 + val8, val8 + val7);
315 
316   // Test 256-bit addition
317   LL_UInt256 val9({0x1f1e1d1c1b1a1918, 0xf1f2f3f4f5f6f7f8, 0x0123456789abcdef,
318                    0xfedcba9876543210});
319   LL_UInt256 val10({0x1111222233334444, 0xaaaabbbbccccdddd, 0x1111222233334444,
320                     0xaaaabbbbccccdddd});
321   LL_UInt256 result5({0x302f3f3e4e4d5d5c, 0x9c9dafb0c2c3d5d5,
322                       0x12346789bcdf1234, 0xa987765443210fed});
323   EXPECT_EQ(val9 + val10, result5);
324   EXPECT_EQ(val9 + val10, val10 + val9);
325 }
326 
327 TEST(LlvmLibcUIntClassTest, SubtractionTests) {
328   LL_UInt128 val1(12345);
329   LL_UInt128 val2(54321);
330   LL_UInt128 result1({0xffffffffffff5c08, 0xffffffffffffffff});
331   LL_UInt128 result2(0xa3f8);
332   EXPECT_EQ(val1 - val2, result1);
333   EXPECT_EQ(val1, val2 + result1);
334   EXPECT_EQ(val2 - val1, result2);
335   EXPECT_EQ(val2, val1 + result2);
336 
337   LL_UInt128 val3({0xf000000000000001, 0});
338   LL_UInt128 val4({0x100000000000000f, 0});
339   LL_UInt128 result3(0xdffffffffffffff2);
340   LL_UInt128 result4({0x200000000000000e, 0xffffffffffffffff});
341   EXPECT_EQ(val3 - val4, result3);
342   EXPECT_EQ(val3, val4 + result3);
343   EXPECT_EQ(val4 - val3, result4);
344   EXPECT_EQ(val4, val3 + result4);
345 
346   LL_UInt128 val5({0x0123456789abcdef, 0xfedcba9876543210});
347   LL_UInt128 val6({0x1111222233334444, 0xaaaabbbbccccdddd});
348   LL_UInt128 result5({0xf0122345567889ab, 0x5431fedca9875432});
349   LL_UInt128 result6({0x0feddcbaa9877655, 0xabce01235678abcd});
350   EXPECT_EQ(val5 - val6, result5);
351   EXPECT_EQ(val5, val6 + result5);
352   EXPECT_EQ(val6 - val5, result6);
353   EXPECT_EQ(val6, val5 + result6);
354 }
355 
356 TEST(LlvmLibcUIntClassTest, MultiplicationTests) {
357   LL_UInt128 val1({5, 0});
358   LL_UInt128 val2({10, 0});
359   LL_UInt128 result1({50, 0});
360   EXPECT_EQ((val1 * val2), result1);
361   EXPECT_EQ((val1 * val2), (val2 * val1)); // multiplication is commutative
362 
363   // Check that the multiplication works accross the whole number
364   LL_UInt128 val3({0xf, 0});
365   LL_UInt128 val4({0x1111111111111111, 0x1111111111111111});
366   LL_UInt128 result2({0xffffffffffffffff, 0xffffffffffffffff});
367   EXPECT_EQ((val3 * val4), result2);
368   EXPECT_EQ((val3 * val4), (val4 * val3));
369 
370   // Check that multiplication doesn't reorder the bits.
371   LL_UInt128 val5({2, 0});
372   LL_UInt128 val6({0x1357024675316420, 0x0123456776543210});
373   LL_UInt128 result3({0x26ae048cea62c840, 0x02468aceeca86420});
374 
375   EXPECT_EQ((val5 * val6), result3);
376   EXPECT_EQ((val5 * val6), (val6 * val5));
377 
378   // Make sure that multiplication handles overflow correctly.
379   LL_UInt128 val7(2);
380   LL_UInt128 val8({0x8000800080008000, 0x8000800080008000});
381   LL_UInt128 result4({0x0001000100010000, 0x0001000100010001});
382   EXPECT_EQ((val7 * val8), result4);
383   EXPECT_EQ((val7 * val8), (val8 * val7));
384 
385   // val9 is the 128 bit mantissa of 1e60 as a float, val10 is the mantissa for
386   // 1e-60. They almost cancel on the high bits, but the result we're looking
387   // for is just the low bits. The full result would be
388   // 0x7fffffffffffffffffffffffffffffff3a4f32d17f40d08f917cf11d1e039c50
389   LL_UInt128 val9({0x01D762422C946590, 0x9F4F2726179A2245});
390   LL_UInt128 val10({0x3792F412CB06794D, 0xCDB02555653131B6});
391   LL_UInt128 result5({0x917cf11d1e039c50, 0x3a4f32d17f40d08f});
392   EXPECT_EQ((val9 * val10), result5);
393   EXPECT_EQ((val9 * val10), (val10 * val9));
394 
395   // Test 192-bit multiplication
396   LL_UInt192 val11(
397       {0xffffffffffffffff, 0x01D762422C946590, 0x9F4F2726179A2245});
398   LL_UInt192 val12(
399       {0xffffffffffffffff, 0x3792F412CB06794D, 0xCDB02555653131B6});
400 
401   LL_UInt192 result6(
402       {0x0000000000000001, 0xc695a9ab08652121, 0x5de7faf698d32732});
403   EXPECT_EQ((val11 * val12), result6);
404   EXPECT_EQ((val11 * val12), (val12 * val11));
405 
406   LL_UInt256 val13({0xffffffffffffffff, 0x01D762422C946590, 0x9F4F2726179A2245,
407                     0xffffffffffffffff});
408   LL_UInt256 val14({0xffffffffffffffff, 0xffffffffffffffff, 0x3792F412CB06794D,
409                     0xCDB02555653131B6});
410   LL_UInt256 result7({0x0000000000000001, 0xfe289dbdd36b9a6f,
411                       0x291de4c71d5f646c, 0xfd37221cb06d4978});
412   EXPECT_EQ((val13 * val14), result7);
413   EXPECT_EQ((val13 * val14), (val14 * val13));
414 }
415 
416 TEST(LlvmLibcUIntClassTest, DivisionTests) {
417   LL_UInt128 val1({10, 0});
418   LL_UInt128 val2({5, 0});
419   LL_UInt128 result1({2, 0});
420   EXPECT_EQ((val1 / val2), result1);
421   EXPECT_EQ((val1 / result1), val2);
422 
423   // Check that the division works accross the whole number
424   LL_UInt128 val3({0xffffffffffffffff, 0xffffffffffffffff});
425   LL_UInt128 val4({0xf, 0});
426   LL_UInt128 result2({0x1111111111111111, 0x1111111111111111});
427   EXPECT_EQ((val3 / val4), result2);
428   EXPECT_EQ((val3 / result2), val4);
429 
430   // Check that division doesn't reorder the bits.
431   LL_UInt128 val5({0x26ae048cea62c840, 0x02468aceeca86420});
432   LL_UInt128 val6({2, 0});
433   LL_UInt128 result3({0x1357024675316420, 0x0123456776543210});
434   EXPECT_EQ((val5 / val6), result3);
435   EXPECT_EQ((val5 / result3), val6);
436 
437   // Make sure that division handles inexact results correctly.
438   LL_UInt128 val7({1001, 0});
439   LL_UInt128 val8({10, 0});
440   LL_UInt128 result4({100, 0});
441   EXPECT_EQ((val7 / val8), result4);
442   EXPECT_EQ((val7 / result4), val8);
443 
444   // Make sure that division handles divisors of one correctly.
445   LL_UInt128 val9({0x1234567812345678, 0x9abcdef09abcdef0});
446   LL_UInt128 val10({1, 0});
447   LL_UInt128 result5({0x1234567812345678, 0x9abcdef09abcdef0});
448   EXPECT_EQ((val9 / val10), result5);
449   EXPECT_EQ((val9 / result5), val10);
450 
451   // Make sure that division handles results of slightly more than 1 correctly.
452   LL_UInt128 val11({1050, 0});
453   LL_UInt128 val12({1030, 0});
454   LL_UInt128 result6({1, 0});
455   EXPECT_EQ((val11 / val12), result6);
456 
457   // Make sure that division handles dividing by zero correctly.
458   LL_UInt128 val13({1234, 0});
459   LL_UInt128 val14({0, 0});
460   EXPECT_FALSE(val13.div(val14).has_value());
461 }
462 
463 TEST(LlvmLibcUIntClassTest, ModuloTests) {
464   LL_UInt128 val1({10, 0});
465   LL_UInt128 val2({5, 0});
466   LL_UInt128 result1({0, 0});
467   EXPECT_EQ((val1 % val2), result1);
468 
469   LL_UInt128 val3({101, 0});
470   LL_UInt128 val4({10, 0});
471   LL_UInt128 result2({1, 0});
472   EXPECT_EQ((val3 % val4), result2);
473 
474   LL_UInt128 val5({10000001, 0});
475   LL_UInt128 val6({10, 0});
476   LL_UInt128 result3({1, 0});
477   EXPECT_EQ((val5 % val6), result3);
478 
479   LL_UInt128 val7({12345, 10});
480   LL_UInt128 val8({0, 1});
481   LL_UInt128 result4({12345, 0});
482   EXPECT_EQ((val7 % val8), result4);
483 
484   LL_UInt128 val9({12345, 10});
485   LL_UInt128 val10({0, 11});
486   LL_UInt128 result5({12345, 10});
487   EXPECT_EQ((val9 % val10), result5);
488 
489   LL_UInt128 val11({10, 10});
490   LL_UInt128 val12({10, 10});
491   LL_UInt128 result6({0, 0});
492   EXPECT_EQ((val11 % val12), result6);
493 
494   LL_UInt128 val13({12345, 0});
495   LL_UInt128 val14({1, 0});
496   LL_UInt128 result7({0, 0});
497   EXPECT_EQ((val13 % val14), result7);
498 
499   LL_UInt128 val15({0xffffffffffffffff, 0xffffffffffffffff});
500   LL_UInt128 val16({0x1111111111111111, 0x111111111111111});
501   LL_UInt128 result8({0xf, 0});
502   EXPECT_EQ((val15 % val16), result8);
503 
504   LL_UInt128 val17({5076944270305263619, 54210108624}); // (10 ^ 30) + 3
505   LL_UInt128 val18({10, 0});
506   LL_UInt128 result9({3, 0});
507   EXPECT_EQ((val17 % val18), result9);
508 }
509 
510 TEST(LlvmLibcUIntClassTest, PowerTests) {
511   LL_UInt128 val1({10, 0});
512   val1.pow_n(30);
513   LL_UInt128 result1({5076944270305263616, 54210108624}); // (10 ^ 30)
514   EXPECT_EQ(val1, result1);
515 
516   LL_UInt128 val2({1, 0});
517   val2.pow_n(10);
518   LL_UInt128 result2({1, 0});
519   EXPECT_EQ(val2, result2);
520 
521   LL_UInt128 val3({0, 0});
522   val3.pow_n(10);
523   LL_UInt128 result3({0, 0});
524   EXPECT_EQ(val3, result3);
525 
526   LL_UInt128 val4({10, 0});
527   val4.pow_n(0);
528   LL_UInt128 result4({1, 0});
529   EXPECT_EQ(val4, result4);
530 
531   // Test zero to the zero. Currently it returns 1, since that's the easiest
532   // result.
533   LL_UInt128 val5({0, 0});
534   val5.pow_n(0);
535   LL_UInt128 result5({1, 0});
536   EXPECT_EQ(val5, result5);
537 
538   // Test a number that overflows. 100 ^ 20 is larger than 2 ^ 128.
539   LL_UInt128 val6({100, 0});
540   val6.pow_n(20);
541   LL_UInt128 result6({0xb9f5610000000000, 0x6329f1c35ca4bfab});
542   EXPECT_EQ(val6, result6);
543 
544   // Test that both halves of the number are being used.
545   LL_UInt128 val7({1, 1});
546   val7.pow_n(2);
547   LL_UInt128 result7({1, 2});
548   EXPECT_EQ(val7, result7);
549 
550   LL_UInt128 val_pow_two;
551   LL_UInt128 result_pow_two;
552   for (size_t i = 0; i < 128; ++i) {
553     val_pow_two = 2;
554     val_pow_two.pow_n(i);
555     result_pow_two = 1;
556     result_pow_two = result_pow_two << i;
557     EXPECT_EQ(val_pow_two, result_pow_two);
558   }
559 }
560 
561 TEST(LlvmLibcUIntClassTest, ShiftLeftTests) {
562   LL_UInt128 val1(0x0123456789abcdef);
563   LL_UInt128 result1(0x123456789abcdef0);
564   EXPECT_EQ((val1 << 4), result1);
565 
566   LL_UInt128 val2({0x13579bdf02468ace, 0x123456789abcdef0});
567   LL_UInt128 result2({0x02468ace00000000, 0x9abcdef013579bdf});
568   EXPECT_EQ((val2 << 32), result2);
569   LL_UInt128 val22 = val2;
570   val22 <<= 32;
571   EXPECT_EQ(val22, result2);
572 
573   LL_UInt128 result3({0, 0x13579bdf02468ace});
574   EXPECT_EQ((val2 << 64), result3);
575 
576   LL_UInt128 result4({0, 0x02468ace00000000});
577   EXPECT_EQ((val2 << 96), result4);
578 
579   LL_UInt128 result5({0, 0x2468ace000000000});
580   EXPECT_EQ((val2 << 100), result5);
581 
582   LL_UInt192 val3({1, 0, 0});
583   LL_UInt192 result7({0, 1, 0});
584   EXPECT_EQ((val3 << 64), result7);
585 }
586 
587 TEST(LlvmLibcUIntClassTest, ShiftRightTests) {
588   LL_UInt128 val1(0x0123456789abcdef);
589   LL_UInt128 result1(0x00123456789abcde);
590   EXPECT_EQ((val1 >> 4), result1);
591 
592   LL_UInt128 val2({0x13579bdf02468ace, 0x123456789abcdef0});
593   LL_UInt128 result2({0x9abcdef013579bdf, 0x0000000012345678});
594   EXPECT_EQ((val2 >> 32), result2);
595   LL_UInt128 val22 = val2;
596   val22 >>= 32;
597   EXPECT_EQ(val22, result2);
598 
599   LL_UInt128 result3({0x123456789abcdef0, 0});
600   EXPECT_EQ((val2 >> 64), result3);
601 
602   LL_UInt128 result4({0x0000000012345678, 0});
603   EXPECT_EQ((val2 >> 96), result4);
604 
605   LL_UInt128 result5({0x0000000001234567, 0});
606   EXPECT_EQ((val2 >> 100), result5);
607 
608   LL_UInt128 v1({0x1111222233334444, 0xaaaabbbbccccdddd});
609   LL_UInt128 r1({0xaaaabbbbccccdddd, 0});
610   EXPECT_EQ((v1 >> 64), r1);
611 
612   LL_UInt192 v2({0x1111222233334444, 0x5555666677778888, 0xaaaabbbbccccdddd});
613   LL_UInt192 r2({0x5555666677778888, 0xaaaabbbbccccdddd, 0});
614   LL_UInt192 r3({0xaaaabbbbccccdddd, 0, 0});
615   EXPECT_EQ((v2 >> 64), r2);
616   EXPECT_EQ((v2 >> 128), r3);
617   EXPECT_EQ((r2 >> 64), r3);
618 
619   LL_UInt192 val3({0, 0, 1});
620   LL_UInt192 result7({0, 1, 0});
621   EXPECT_EQ((val3 >> 64), result7);
622 }
623 
624 TEST(LlvmLibcUIntClassTest, AndTests) {
625   LL_UInt128 base({0xffff00000000ffff, 0xffffffff00000000});
626   LL_UInt128 val128({0xf0f0f0f00f0f0f0f, 0xff00ff0000ff00ff});
627   uint64_t val64 = 0xf0f0f0f00f0f0f0f;
628   int val32 = 0x0f0f0f0f;
629   LL_UInt128 result128({0xf0f0000000000f0f, 0xff00ff0000000000});
630   LL_UInt128 result64(0xf0f0000000000f0f);
631   LL_UInt128 result32(0x00000f0f);
632   EXPECT_EQ((base & val128), result128);
633   EXPECT_EQ((base & val64), result64);
634   EXPECT_EQ((base & val32), result32);
635 }
636 
637 TEST(LlvmLibcUIntClassTest, OrTests) {
638   LL_UInt128 base({0xffff00000000ffff, 0xffffffff00000000});
639   LL_UInt128 val128({0xf0f0f0f00f0f0f0f, 0xff00ff0000ff00ff});
640   uint64_t val64 = 0xf0f0f0f00f0f0f0f;
641   int val32 = 0x0f0f0f0f;
642   LL_UInt128 result128({0xfffff0f00f0fffff, 0xffffffff00ff00ff});
643   LL_UInt128 result64({0xfffff0f00f0fffff, 0xffffffff00000000});
644   LL_UInt128 result32({0xffff00000f0fffff, 0xffffffff00000000});
645   EXPECT_EQ((base | val128), result128);
646   EXPECT_EQ((base | val64), result64);
647   EXPECT_EQ((base | val32), result32);
648 }
649 
650 TEST(LlvmLibcUIntClassTest, CompoundAssignments) {
651   LL_UInt128 x({0xffff00000000ffff, 0xffffffff00000000});
652   LL_UInt128 b({0xf0f0f0f00f0f0f0f, 0xff00ff0000ff00ff});
653 
654   LL_UInt128 a = x;
655   a |= b;
656   LL_UInt128 or_result({0xfffff0f00f0fffff, 0xffffffff00ff00ff});
657   EXPECT_EQ(a, or_result);
658 
659   a = x;
660   a &= b;
661   LL_UInt128 and_result({0xf0f0000000000f0f, 0xff00ff0000000000});
662   EXPECT_EQ(a, and_result);
663 
664   a = x;
665   a ^= b;
666   LL_UInt128 xor_result({0x0f0ff0f00f0ff0f0, 0x00ff00ff00ff00ff});
667   EXPECT_EQ(a, xor_result);
668 
669   a = LL_UInt128(uint64_t(0x0123456789abcdef));
670   LL_UInt128 shift_left_result(uint64_t(0x123456789abcdef0));
671   a <<= 4;
672   EXPECT_EQ(a, shift_left_result);
673 
674   a = LL_UInt128(uint64_t(0x123456789abcdef1));
675   LL_UInt128 shift_right_result(uint64_t(0x0123456789abcdef));
676   a >>= 4;
677   EXPECT_EQ(a, shift_right_result);
678 
679   a = LL_UInt128({0xf000000000000001, 0});
680   b = LL_UInt128({0x100000000000000f, 0});
681   LL_UInt128 add_result({0x10, 0x1});
682   a += b;
683   EXPECT_EQ(a, add_result);
684 
685   a = LL_UInt128({0xf, 0});
686   b = LL_UInt128({0x1111111111111111, 0x1111111111111111});
687   LL_UInt128 mul_result({0xffffffffffffffff, 0xffffffffffffffff});
688   a *= b;
689   EXPECT_EQ(a, mul_result);
690 }
691 
692 TEST(LlvmLibcUIntClassTest, UnaryPredecrement) {
693   LL_UInt128 a = LL_UInt128({0x1111111111111111, 0x1111111111111111});
694   ++a;
695   EXPECT_EQ(a, LL_UInt128({0x1111111111111112, 0x1111111111111111}));
696 
697   a = LL_UInt128({0xffffffffffffffff, 0x0});
698   ++a;
699   EXPECT_EQ(a, LL_UInt128({0x0, 0x1}));
700 
701   a = LL_UInt128({0xffffffffffffffff, 0xffffffffffffffff});
702   ++a;
703   EXPECT_EQ(a, LL_UInt128({0x0, 0x0}));
704 }
705 
706 TEST(LlvmLibcUIntClassTest, EqualsTests) {
707   LL_UInt128 a1({0xffffffff00000000, 0xffff00000000ffff});
708   LL_UInt128 a2({0xffffffff00000000, 0xffff00000000ffff});
709   LL_UInt128 b({0xff00ff0000ff00ff, 0xf0f0f0f00f0f0f0f});
710   LL_UInt128 a_reversed({0xffff00000000ffff, 0xffffffff00000000});
711   LL_UInt128 a_upper(0xffff00000000ffff);
712   LL_UInt128 a_lower(0xffffffff00000000);
713   ASSERT_TRUE(a1 == a1);
714   ASSERT_TRUE(a1 == a2);
715   ASSERT_FALSE(a1 == b);
716   ASSERT_FALSE(a1 == a_reversed);
717   ASSERT_FALSE(a1 == a_lower);
718   ASSERT_FALSE(a1 == a_upper);
719   ASSERT_TRUE(a_lower != a_upper);
720 }
721 
722 TEST(LlvmLibcUIntClassTest, ComparisonTests) {
723   LL_UInt128 a({0xffffffff00000000, 0xffff00000000ffff});
724   LL_UInt128 b({0xff00ff0000ff00ff, 0xf0f0f0f00f0f0f0f});
725   EXPECT_GT(a, b);
726   EXPECT_GE(a, b);
727   EXPECT_LT(b, a);
728   EXPECT_LE(b, a);
729 
730   LL_UInt128 x(0xffffffff00000000);
731   LL_UInt128 y(0x00000000ffffffff);
732   EXPECT_GT(x, y);
733   EXPECT_GE(x, y);
734   EXPECT_LT(y, x);
735   EXPECT_LE(y, x);
736 
737   EXPECT_LE(a, a);
738   EXPECT_GE(a, a);
739 }
740 
741 TEST(LlvmLibcUIntClassTest, FullMulTests) {
742   LL_UInt128 a({0xffffffffffffffffULL, 0xffffffffffffffffULL});
743   LL_UInt128 b({0xfedcba9876543210ULL, 0xfefdfcfbfaf9f8f7ULL});
744   LL_UInt256 r({0x0123456789abcdf0ULL, 0x0102030405060708ULL,
745                 0xfedcba987654320fULL, 0xfefdfcfbfaf9f8f7ULL});
746   LL_UInt128 r_hi({0xfedcba987654320eULL, 0xfefdfcfbfaf9f8f7ULL});
747 
748   EXPECT_EQ(a.ful_mul(b), r);
749   EXPECT_EQ(a.quick_mul_hi(b), r_hi);
750 
751   LL_UInt192 c(
752       {0x7766554433221101ULL, 0xffeeddccbbaa9988ULL, 0x1f2f3f4f5f6f7f8fULL});
753   LL_UInt320 rr({0x8899aabbccddeeffULL, 0x0011223344556677ULL,
754                  0x583715f4d3b29171ULL, 0xffeeddccbbaa9988ULL,
755                  0x1f2f3f4f5f6f7f8fULL});
756 
757   EXPECT_EQ(a.ful_mul(c), rr);
758   EXPECT_EQ(a.ful_mul(c), c.ful_mul(a));
759 }
760 
761 #define TEST_QUICK_MUL_HI(Bits, Error)                                         \
762   do {                                                                         \
763     LL_UInt##Bits a = ~LL_UInt##Bits(0);                                       \
764     LL_UInt##Bits hi = a.quick_mul_hi(a);                                      \
765     LL_UInt##Bits trunc = static_cast<LL_UInt##Bits>(a.ful_mul(a) >> Bits);    \
766     uint64_t overflow = trunc.sub_overflow(hi);                                \
767     EXPECT_EQ(overflow, uint64_t(0));                                          \
768     EXPECT_LE(uint64_t(trunc), uint64_t(Error));                               \
769   } while (0)
770 
771 TEST(LlvmLibcUIntClassTest, QuickMulHiTests) {
772   TEST_QUICK_MUL_HI(128, 1);
773   TEST_QUICK_MUL_HI(192, 2);
774   TEST_QUICK_MUL_HI(256, 3);
775   TEST_QUICK_MUL_HI(512, 7);
776 }
777 
778 TEST(LlvmLibcUIntClassTest, ConstexprInitTests) {
779   constexpr LL_UInt128 add = LL_UInt128(1) + LL_UInt128(2);
780   ASSERT_EQ(add, LL_UInt128(3));
781   constexpr LL_UInt128 sub = LL_UInt128(5) - LL_UInt128(4);
782   ASSERT_EQ(sub, LL_UInt128(1));
783 }
784 
785 #define TEST_QUICK_DIV_UINT32_POW2(x, e)                                       \
786   do {                                                                         \
787     LL_UInt320 y({0x8899aabbccddeeffULL, 0x0011223344556677ULL,                \
788                   0x583715f4d3b29171ULL, 0xffeeddccbbaa9988ULL,                \
789                   0x1f2f3f4f5f6f7f8fULL});                                     \
790     LL_UInt320 d = LL_UInt320(x);                                              \
791     d <<= e;                                                                   \
792     LL_UInt320 q1 = y / d;                                                     \
793     LL_UInt320 r1 = y % d;                                                     \
794     LL_UInt320 r2 = *y.div_uint_half_times_pow_2(x, e);                        \
795     EXPECT_EQ(q1, y);                                                          \
796     EXPECT_EQ(r1, r2);                                                         \
797   } while (0)
798 
799 TEST(LlvmLibcUIntClassTest, DivUInt32TimesPow2Tests) {
800   for (size_t i = 0; i < 320; i += 32) {
801     TEST_QUICK_DIV_UINT32_POW2(1, i);
802     TEST_QUICK_DIV_UINT32_POW2(13151719, i);
803   }
804 
805   TEST_QUICK_DIV_UINT32_POW2(1, 75);
806   TEST_QUICK_DIV_UINT32_POW2(1, 101);
807 
808   TEST_QUICK_DIV_UINT32_POW2(1000000000, 75);
809   TEST_QUICK_DIV_UINT32_POW2(1000000000, 101);
810 }
811 
812 TEST(LlvmLibcUIntClassTest, ComparisonInt128Tests) {
813   LL_Int128 a(123);
814   LL_Int128 b(0);
815   LL_Int128 c(-1);
816 
817   ASSERT_TRUE(a == a);
818   ASSERT_TRUE(b == b);
819   ASSERT_TRUE(c == c);
820 
821   ASSERT_TRUE(a != b);
822   ASSERT_TRUE(a != c);
823   ASSERT_TRUE(b != a);
824   ASSERT_TRUE(b != c);
825   ASSERT_TRUE(c != a);
826   ASSERT_TRUE(c != b);
827 
828   ASSERT_TRUE(a > b);
829   ASSERT_TRUE(a >= b);
830   ASSERT_TRUE(a > c);
831   ASSERT_TRUE(a >= c);
832   ASSERT_TRUE(b > c);
833   ASSERT_TRUE(b >= c);
834 
835   ASSERT_TRUE(b < a);
836   ASSERT_TRUE(b <= a);
837   ASSERT_TRUE(c < a);
838   ASSERT_TRUE(c <= a);
839   ASSERT_TRUE(c < b);
840   ASSERT_TRUE(c <= b);
841 }
842 
843 TEST(LlvmLibcUIntClassTest, BasicArithmeticInt128Tests) {
844   LL_Int128 a(123);
845   LL_Int128 b(0);
846   LL_Int128 c(-3);
847 
848   ASSERT_EQ(a * a, LL_Int128(123 * 123));
849   ASSERT_EQ(a * c, LL_Int128(-369));
850   ASSERT_EQ(c * a, LL_Int128(-369));
851   ASSERT_EQ(c * c, LL_Int128(9));
852   ASSERT_EQ(a * b, b);
853   ASSERT_EQ(b * a, b);
854   ASSERT_EQ(b * c, b);
855   ASSERT_EQ(c * b, b);
856 }
857 
858 #ifdef LIBC_TYPES_HAS_INT128
859 
860 TEST(LlvmLibcUIntClassTest, ConstructorFromUInt128Tests) {
861   __uint128_t a = (__uint128_t(123) << 64) + 1;
862   __int128_t b = -static_cast<__int128_t>(a);
863   LL_Int128 c(a);
864   LL_Int128 d(b);
865 
866   LL_Int192 e(a);
867   LL_Int192 f(b);
868 
869   ASSERT_EQ(static_cast<int>(c), 1);
870   ASSERT_EQ(static_cast<int>(c >> 64), 123);
871   ASSERT_EQ(static_cast<uint64_t>(d), static_cast<uint64_t>(b));
872   ASSERT_EQ(static_cast<uint64_t>(d >> 64), static_cast<uint64_t>(b >> 64));
873   ASSERT_EQ(c + d, LL_Int128(a + b));
874 
875   ASSERT_EQ(static_cast<int>(e), 1);
876   ASSERT_EQ(static_cast<int>(e >> 64), 123);
877   ASSERT_EQ(static_cast<uint64_t>(f), static_cast<uint64_t>(b));
878   ASSERT_EQ(static_cast<uint64_t>(f >> 64), static_cast<uint64_t>(b >> 64));
879   ASSERT_EQ(LL_UInt192(e + f), LL_UInt192(a + b));
880 }
881 
882 TEST(LlvmLibcUIntClassTest, WordTypeUInt128Tests) {
883   using LL_UInt256_128 = BigInt<256, false, __uint128_t>;
884   using LL_UInt128_128 = BigInt<128, false, __uint128_t>;
885 
886   LL_UInt256_128 a(1);
887 
888   ASSERT_EQ(static_cast<int>(a), 1);
889   a = (a << 128) + 2;
890   ASSERT_EQ(static_cast<int>(a), 2);
891   ASSERT_EQ(static_cast<uint64_t>(a), uint64_t(2));
892   a = (a << 32) + 3;
893   ASSERT_EQ(static_cast<int>(a), 3);
894   ASSERT_EQ(static_cast<uint64_t>(a), uint64_t(0x2'0000'0003));
895   ASSERT_EQ(static_cast<int>(a >> 32), 2);
896   ASSERT_EQ(static_cast<int>(a >> (128 + 32)), 1);
897 
898   LL_UInt128_128 b(__uint128_t(1) << 127);
899   LL_UInt128_128 c(b);
900   a = b.ful_mul(c);
901 
902   ASSERT_EQ(static_cast<int>(a >> 254), 1);
903 
904   LL_UInt256_128 d = LL_UInt256_128(123) << 4;
905   ASSERT_EQ(static_cast<int>(d), 123 << 4);
906   LL_UInt256_128 e = a / d;
907   LL_UInt256_128 f = a % d;
908   LL_UInt256_128 r = *a.div_uint_half_times_pow_2(123, 4);
909   EXPECT_TRUE(e == a);
910   EXPECT_TRUE(f == r);
911 }
912 
913 #endif // LIBC_TYPES_HAS_INT128
914 
915 TEST(LlvmLibcUIntClassTest, OtherWordTypeTests) {
916   using LL_UInt96 = BigInt<96, false, uint32_t>;
917 
918   LL_UInt96 a(1);
919 
920   ASSERT_EQ(static_cast<int>(a), 1);
921   a = (a << 32) + 2;
922   ASSERT_EQ(static_cast<int>(a), 2);
923   ASSERT_EQ(static_cast<uint64_t>(a), uint64_t(0x1'0000'0002));
924   a = (a << 32) + 3;
925   ASSERT_EQ(static_cast<int>(a), 3);
926   ASSERT_EQ(static_cast<int>(a >> 32), 2);
927   ASSERT_EQ(static_cast<int>(a >> 64), 1);
928 }
929 
930 } // namespace LIBC_NAMESPACE_DECL
931