xref: /llvm-project/llvm/unittests/Support/MathExtrasTest.cpp (revision 0f52c1f86c62dadf69a7b732779abf59edea3d5c)
1 //===- unittests/Support/MathExtrasTest.cpp - math utils tests ------------===//
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 "llvm/Support/MathExtras.h"
10 #include "gtest/gtest.h"
11 
12 using namespace llvm;
13 
14 namespace {
15 
16 TEST(MathExtras, onesMask) {
17   EXPECT_EQ(0U, maskLeadingOnes<uint8_t>(0));
18   EXPECT_EQ(0U, maskTrailingOnes<uint8_t>(0));
19   EXPECT_EQ(0U, maskLeadingOnes<uint16_t>(0));
20   EXPECT_EQ(0U, maskTrailingOnes<uint16_t>(0));
21   EXPECT_EQ(0U, maskLeadingOnes<uint32_t>(0));
22   EXPECT_EQ(0U, maskTrailingOnes<uint32_t>(0));
23   EXPECT_EQ(0U, maskLeadingOnes<uint64_t>(0));
24   EXPECT_EQ(0U, maskTrailingOnes<uint64_t>(0));
25 
26   EXPECT_EQ(0x00000003U, maskTrailingOnes<uint32_t>(2U));
27   EXPECT_EQ(0xC0000000U, maskLeadingOnes<uint32_t>(2U));
28 
29   EXPECT_EQ(0x000007FFU, maskTrailingOnes<uint32_t>(11U));
30   EXPECT_EQ(0xFFE00000U, maskLeadingOnes<uint32_t>(11U));
31 
32   EXPECT_EQ(0xFFFFFFFFU, maskTrailingOnes<uint32_t>(32U));
33   EXPECT_EQ(0xFFFFFFFFU, maskLeadingOnes<uint32_t>(32U));
34   EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, maskTrailingOnes<uint64_t>(64U));
35   EXPECT_EQ(0xFFFFFFFFFFFFFFFFULL, maskLeadingOnes<uint64_t>(64U));
36 
37   EXPECT_EQ(0x0000FFFFFFFFFFFFULL, maskTrailingOnes<uint64_t>(48U));
38   EXPECT_EQ(0xFFFFFFFFFFFF0000ULL, maskLeadingOnes<uint64_t>(48U));
39 }
40 
41 TEST(MathExtras, isIntN) {
42   EXPECT_TRUE(isIntN(16, 32767));
43   EXPECT_FALSE(isIntN(16, 32768));
44 }
45 
46 TEST(MathExtras, isUIntN) {
47   EXPECT_TRUE(isUIntN(16, 65535));
48   EXPECT_FALSE(isUIntN(16, 65536));
49   EXPECT_TRUE(isUIntN(1, 0));
50   EXPECT_TRUE(isUIntN(6, 63));
51 }
52 
53 TEST(MathExtras, maxIntN) {
54   EXPECT_EQ(32767, maxIntN(16));
55   EXPECT_EQ(2147483647, maxIntN(32));
56   EXPECT_EQ(std::numeric_limits<int32_t>::max(), maxIntN(32));
57   EXPECT_EQ(std::numeric_limits<int64_t>::max(), maxIntN(64));
58 }
59 
60 TEST(MathExtras, minIntN) {
61   EXPECT_EQ(-32768LL, minIntN(16));
62   EXPECT_EQ(-64LL, minIntN(7));
63   EXPECT_EQ(std::numeric_limits<int32_t>::min(), minIntN(32));
64   EXPECT_EQ(std::numeric_limits<int64_t>::min(), minIntN(64));
65 }
66 
67 TEST(MathExtras, maxUIntN) {
68   EXPECT_EQ(0xffffULL, maxUIntN(16));
69   EXPECT_EQ(0xffffffffULL, maxUIntN(32));
70   EXPECT_EQ(0xffffffffffffffffULL, maxUIntN(64));
71   EXPECT_EQ(1ULL, maxUIntN(1));
72   EXPECT_EQ(0x0fULL, maxUIntN(4));
73 }
74 
75 TEST(MathExtras, reverseBits) {
76   uint8_t NZ8 = 42;
77   uint16_t NZ16 = 42;
78   uint32_t NZ32 = 42;
79   uint64_t NZ64 = 42;
80   EXPECT_EQ(0x54ULL, reverseBits(NZ8));
81   EXPECT_EQ(0x5400ULL, reverseBits(NZ16));
82   EXPECT_EQ(0x54000000ULL, reverseBits(NZ32));
83   EXPECT_EQ(0x5400000000000000ULL, reverseBits(NZ64));
84 }
85 
86 TEST(MathExtras, isShiftedMask_32) {
87   EXPECT_FALSE(isShiftedMask_32(0x01010101));
88   EXPECT_TRUE(isShiftedMask_32(0xf0000000));
89   EXPECT_TRUE(isShiftedMask_32(0xffff0000));
90   EXPECT_TRUE(isShiftedMask_32(0xff << 1));
91 
92   unsigned MaskIdx, MaskLen;
93   EXPECT_FALSE(isShiftedMask_32(0x01010101, MaskIdx, MaskLen));
94   EXPECT_TRUE(isShiftedMask_32(0xf0000000, MaskIdx, MaskLen));
95   EXPECT_EQ(28, (int)MaskIdx);
96   EXPECT_EQ(4, (int)MaskLen);
97   EXPECT_TRUE(isShiftedMask_32(0xffff0000, MaskIdx, MaskLen));
98   EXPECT_EQ(16, (int)MaskIdx);
99   EXPECT_EQ(16, (int)MaskLen);
100   EXPECT_TRUE(isShiftedMask_32(0xff << 1, MaskIdx, MaskLen));
101   EXPECT_EQ(1, (int)MaskIdx);
102   EXPECT_EQ(8, (int)MaskLen);
103 }
104 
105 TEST(MathExtras, isShiftedMask_64) {
106   EXPECT_FALSE(isShiftedMask_64(0x0101010101010101ull));
107   EXPECT_TRUE(isShiftedMask_64(0xf000000000000000ull));
108   EXPECT_TRUE(isShiftedMask_64(0xffff000000000000ull));
109   EXPECT_TRUE(isShiftedMask_64(0xffull << 55));
110 
111   unsigned MaskIdx, MaskLen;
112   EXPECT_FALSE(isShiftedMask_64(0x0101010101010101ull, MaskIdx, MaskLen));
113   EXPECT_TRUE(isShiftedMask_64(0xf000000000000000ull, MaskIdx, MaskLen));
114   EXPECT_EQ(60, (int)MaskIdx);
115   EXPECT_EQ(4, (int)MaskLen);
116   EXPECT_TRUE(isShiftedMask_64(0xffff000000000000ull, MaskIdx, MaskLen));
117   EXPECT_EQ(48, (int)MaskIdx);
118   EXPECT_EQ(16, (int)MaskLen);
119   EXPECT_TRUE(isShiftedMask_64(0xffull << 55, MaskIdx, MaskLen));
120   EXPECT_EQ(55, (int)MaskIdx);
121   EXPECT_EQ(8, (int)MaskLen);
122 }
123 
124 TEST(MathExtras, isPowerOf2_32) {
125   EXPECT_FALSE(isPowerOf2_32(0));
126   EXPECT_TRUE(isPowerOf2_32(1 << 6));
127   EXPECT_TRUE(isPowerOf2_32(1 << 12));
128   EXPECT_FALSE(isPowerOf2_32((1 << 19) + 3));
129   EXPECT_FALSE(isPowerOf2_32(0xABCDEF0));
130 }
131 
132 TEST(MathExtras, isPowerOf2_64) {
133   EXPECT_FALSE(isPowerOf2_64(0));
134   EXPECT_TRUE(isPowerOf2_64(1LL << 46));
135   EXPECT_TRUE(isPowerOf2_64(1LL << 12));
136   EXPECT_FALSE(isPowerOf2_64((1LL << 53) + 3));
137   EXPECT_FALSE(isPowerOf2_64(0xABCDEF0ABCDEF0LL));
138 }
139 
140 TEST(MathExtras, PowerOf2Ceil) {
141   EXPECT_EQ(0U, PowerOf2Ceil(0U));
142   EXPECT_EQ(8U, PowerOf2Ceil(8U));
143   EXPECT_EQ(8U, PowerOf2Ceil(7U));
144 }
145 
146 TEST(MathExtras, CTLog2) {
147   EXPECT_EQ(CTLog2<1ULL << 0>(), 0U);
148   EXPECT_EQ(CTLog2<1ULL << 1>(), 1U);
149   EXPECT_EQ(CTLog2<1ULL << 2>(), 2U);
150   EXPECT_EQ(CTLog2<1ULL << 3>(), 3U);
151   EXPECT_EQ(CTLog2<1ULL << 4>(), 4U);
152   EXPECT_EQ(CTLog2<1ULL << 5>(), 5U);
153   EXPECT_EQ(CTLog2<1ULL << 6>(), 6U);
154   EXPECT_EQ(CTLog2<1ULL << 7>(), 7U);
155   EXPECT_EQ(CTLog2<1ULL << 8>(), 8U);
156   EXPECT_EQ(CTLog2<1ULL << 9>(), 9U);
157   EXPECT_EQ(CTLog2<1ULL << 10>(), 10U);
158   EXPECT_EQ(CTLog2<1ULL << 11>(), 11U);
159   EXPECT_EQ(CTLog2<1ULL << 12>(), 12U);
160   EXPECT_EQ(CTLog2<1ULL << 13>(), 13U);
161   EXPECT_EQ(CTLog2<1ULL << 14>(), 14U);
162   EXPECT_EQ(CTLog2<1ULL << 15>(), 15U);
163 }
164 
165 TEST(MathExtras, MinAlign) {
166   EXPECT_EQ(1u, MinAlign(2, 3));
167   EXPECT_EQ(2u, MinAlign(2, 4));
168   EXPECT_EQ(1u, MinAlign(17, 64));
169   EXPECT_EQ(256u, MinAlign(256, 512));
170 }
171 
172 TEST(MathExtras, NextPowerOf2) {
173   EXPECT_EQ(4u, NextPowerOf2(3));
174   EXPECT_EQ(16u, NextPowerOf2(15));
175   EXPECT_EQ(256u, NextPowerOf2(128));
176 }
177 
178 TEST(MathExtras, alignTo) {
179   EXPECT_EQ(8u, alignTo(5, 8));
180   EXPECT_EQ(24u, alignTo(17, 8));
181   EXPECT_EQ(0u, alignTo(~0LL, 8));
182 
183   EXPECT_EQ(7u, alignTo(5, 8, 7));
184   EXPECT_EQ(17u, alignTo(17, 8, 1));
185   EXPECT_EQ(3u, alignTo(~0LL, 8, 3));
186   EXPECT_EQ(552u, alignTo(321, 255, 42));
187 }
188 
189 template <typename T> void SaturatingAddTestHelper() {
190   const T Max = std::numeric_limits<T>::max();
191   bool ResultOverflowed;
192 
193   EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2)));
194   EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2), &ResultOverflowed));
195   EXPECT_FALSE(ResultOverflowed);
196 
197   EXPECT_EQ(Max, SaturatingAdd(Max, T(1)));
198   EXPECT_EQ(Max, SaturatingAdd(Max, T(1), &ResultOverflowed));
199   EXPECT_TRUE(ResultOverflowed);
200 
201   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1)));
202   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1), &ResultOverflowed));
203   EXPECT_FALSE(ResultOverflowed);
204 
205   EXPECT_EQ(Max, SaturatingAdd(T(1), Max));
206   EXPECT_EQ(Max, SaturatingAdd(T(1), Max, &ResultOverflowed));
207   EXPECT_TRUE(ResultOverflowed);
208 
209   EXPECT_EQ(Max, SaturatingAdd(Max, Max));
210   EXPECT_EQ(Max, SaturatingAdd(Max, Max, &ResultOverflowed));
211   EXPECT_TRUE(ResultOverflowed);
212 
213   EXPECT_EQ(T(6), SaturatingAdd(T(1), T(2), T(3)));
214   EXPECT_EQ(T(6), SaturatingAdd(T(1), T(2), T(3), &ResultOverflowed));
215   EXPECT_FALSE(ResultOverflowed);
216 
217   EXPECT_EQ(T(10), SaturatingAdd(T(1), T(2), T(3), T(4)));
218   EXPECT_EQ(T(10), SaturatingAdd(T(1), T(2), T(3), T(4), &ResultOverflowed));
219   EXPECT_FALSE(ResultOverflowed);
220 
221   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(0)));
222   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(0), &ResultOverflowed));
223   EXPECT_FALSE(ResultOverflowed);
224 
225   EXPECT_EQ(Max, SaturatingAdd(T(0), T(0), Max));
226   EXPECT_EQ(Max, SaturatingAdd(T(0), T(0), Max, &ResultOverflowed));
227   EXPECT_FALSE(ResultOverflowed);
228 
229   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(1)));
230   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(1), &ResultOverflowed));
231   EXPECT_TRUE(ResultOverflowed);
232 
233   EXPECT_EQ(Max, SaturatingAdd(T(0), T(1), Max));
234   EXPECT_EQ(Max, SaturatingAdd(T(0), T(1), Max, &ResultOverflowed));
235   EXPECT_TRUE(ResultOverflowed);
236 
237   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 2), T(1)));
238   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 2), T(1), &ResultOverflowed));
239   EXPECT_FALSE(ResultOverflowed);
240 
241   EXPECT_EQ(Max, SaturatingAdd(T(1), T(1), T(Max - 2)));
242   EXPECT_EQ(Max, SaturatingAdd(T(1), T(1), T(Max - 2), &ResultOverflowed));
243   EXPECT_FALSE(ResultOverflowed);
244 
245   EXPECT_EQ(Max, SaturatingAdd(Max, Max, Max));
246   EXPECT_EQ(Max, SaturatingAdd(Max, Max, Max, &ResultOverflowed));
247   EXPECT_TRUE(ResultOverflowed);
248 }
249 
250 TEST(MathExtras, SaturatingAdd) {
251   SaturatingAddTestHelper<uint8_t>();
252   SaturatingAddTestHelper<uint16_t>();
253   SaturatingAddTestHelper<uint32_t>();
254   SaturatingAddTestHelper<uint64_t>();
255 }
256 
257 template<typename T>
258 void SaturatingMultiplyTestHelper()
259 {
260   const T Max = std::numeric_limits<T>::max();
261   bool ResultOverflowed;
262 
263   // Test basic multiplication.
264   EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3)));
265   EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3), &ResultOverflowed));
266   EXPECT_FALSE(ResultOverflowed);
267 
268   EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2)));
269   EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2), &ResultOverflowed));
270   EXPECT_FALSE(ResultOverflowed);
271 
272   // Test multiplication by zero.
273   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0)));
274   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0), &ResultOverflowed));
275   EXPECT_FALSE(ResultOverflowed);
276 
277   EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0)));
278   EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0), &ResultOverflowed));
279   EXPECT_FALSE(ResultOverflowed);
280 
281   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1)));
282   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1), &ResultOverflowed));
283   EXPECT_FALSE(ResultOverflowed);
284 
285   EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0)));
286   EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0), &ResultOverflowed));
287   EXPECT_FALSE(ResultOverflowed);
288 
289   EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max));
290   EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max, &ResultOverflowed));
291   EXPECT_FALSE(ResultOverflowed);
292 
293   // Test multiplication by maximum value.
294   EXPECT_EQ(Max, SaturatingMultiply(Max, T(2)));
295   EXPECT_EQ(Max, SaturatingMultiply(Max, T(2), &ResultOverflowed));
296   EXPECT_TRUE(ResultOverflowed);
297 
298   EXPECT_EQ(Max, SaturatingMultiply(T(2), Max));
299   EXPECT_EQ(Max, SaturatingMultiply(T(2), Max, &ResultOverflowed));
300   EXPECT_TRUE(ResultOverflowed);
301 
302   EXPECT_EQ(Max, SaturatingMultiply(Max, Max));
303   EXPECT_EQ(Max, SaturatingMultiply(Max, Max, &ResultOverflowed));
304   EXPECT_TRUE(ResultOverflowed);
305 
306   // Test interesting boundary conditions for algorithm -
307   // ((1 << A) - 1) * ((1 << B) + K) for K in [-1, 0, 1]
308   // and A + B == std::numeric_limits<T>::digits.
309   // We expect overflow iff A > B and K = 1.
310   const int Digits = std::numeric_limits<T>::digits;
311   for (int A = 1, B = Digits - 1; B >= 1; ++A, --B) {
312     for (int K = -1; K <= 1; ++K) {
313       T X = (T(1) << A) - T(1);
314       T Y = (T(1) << B) + K;
315       bool OverflowExpected = A > B && K == 1;
316 
317       if(OverflowExpected) {
318         EXPECT_EQ(Max, SaturatingMultiply(X, Y));
319         EXPECT_EQ(Max, SaturatingMultiply(X, Y, &ResultOverflowed));
320         EXPECT_TRUE(ResultOverflowed);
321       } else {
322         EXPECT_EQ(X * Y, SaturatingMultiply(X, Y));
323         EXPECT_EQ(X * Y, SaturatingMultiply(X, Y, &ResultOverflowed));
324         EXPECT_FALSE(ResultOverflowed);
325       }
326     }
327   }
328 }
329 
330 TEST(MathExtras, SaturatingMultiply) {
331   SaturatingMultiplyTestHelper<uint8_t>();
332   SaturatingMultiplyTestHelper<uint16_t>();
333   SaturatingMultiplyTestHelper<uint32_t>();
334   SaturatingMultiplyTestHelper<uint64_t>();
335 }
336 
337 template<typename T>
338 void SaturatingMultiplyAddTestHelper()
339 {
340   const T Max = std::numeric_limits<T>::max();
341   bool ResultOverflowed;
342 
343   // Test basic multiply-add.
344   EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10)));
345   EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10), &ResultOverflowed));
346   EXPECT_FALSE(ResultOverflowed);
347 
348   // Test multiply overflows, add doesn't overflow
349   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(0), &ResultOverflowed));
350   EXPECT_TRUE(ResultOverflowed);
351 
352   // Test multiply doesn't overflow, add overflows
353   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed));
354   EXPECT_TRUE(ResultOverflowed);
355 
356   // Test multiply-add with Max as operand
357   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed));
358   EXPECT_TRUE(ResultOverflowed);
359 
360   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), Max, T(1), &ResultOverflowed));
361   EXPECT_TRUE(ResultOverflowed);
362 
363   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(1), &ResultOverflowed));
364   EXPECT_TRUE(ResultOverflowed);
365 
366   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, Max, &ResultOverflowed));
367   EXPECT_TRUE(ResultOverflowed);
368 
369   // Test multiply-add with 0 as operand
370   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(1), T(0), &ResultOverflowed));
371   EXPECT_FALSE(ResultOverflowed);
372 
373   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(0), T(1), &ResultOverflowed));
374   EXPECT_FALSE(ResultOverflowed);
375 
376   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(0), T(0), T(1), &ResultOverflowed));
377   EXPECT_FALSE(ResultOverflowed);
378 
379   EXPECT_EQ(T(0), SaturatingMultiplyAdd(T(0), T(0), T(0), &ResultOverflowed));
380   EXPECT_FALSE(ResultOverflowed);
381 
382 }
383 
384 TEST(MathExtras, SaturatingMultiplyAdd) {
385   SaturatingMultiplyAddTestHelper<uint8_t>();
386   SaturatingMultiplyAddTestHelper<uint16_t>();
387   SaturatingMultiplyAddTestHelper<uint32_t>();
388   SaturatingMultiplyAddTestHelper<uint64_t>();
389 }
390 
391 TEST(MathExtras, IsShiftedUInt) {
392   EXPECT_TRUE((isShiftedUInt<1, 0>(0)));
393   EXPECT_TRUE((isShiftedUInt<1, 0>(1)));
394   EXPECT_FALSE((isShiftedUInt<1, 0>(2)));
395   EXPECT_FALSE((isShiftedUInt<1, 0>(3)));
396   EXPECT_FALSE((isShiftedUInt<1, 0>(0x8000000000000000)));
397   EXPECT_TRUE((isShiftedUInt<1, 63>(0x8000000000000000)));
398   EXPECT_TRUE((isShiftedUInt<2, 62>(0xC000000000000000)));
399   EXPECT_FALSE((isShiftedUInt<2, 62>(0xE000000000000000)));
400 
401   // 0x201 is ten bits long and has a 1 in the MSB and LSB.
402   EXPECT_TRUE((isShiftedUInt<10, 5>(uint64_t(0x201) << 5)));
403   EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 4)));
404   EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 6)));
405 }
406 
407 TEST(MathExtras, IsShiftedInt) {
408   EXPECT_TRUE((isShiftedInt<1, 0>(0)));
409   EXPECT_TRUE((isShiftedInt<1, 0>(-1)));
410   EXPECT_FALSE((isShiftedInt<1, 0>(2)));
411   EXPECT_FALSE((isShiftedInt<1, 0>(3)));
412   EXPECT_FALSE((isShiftedInt<1, 0>(0x8000000000000000)));
413   EXPECT_TRUE((isShiftedInt<1, 63>(0x8000000000000000)));
414   EXPECT_TRUE((isShiftedInt<2, 62>(0xC000000000000000)));
415   EXPECT_FALSE((isShiftedInt<2, 62>(0xE000000000000000)));
416 
417   // 0x201 is ten bits long and has a 1 in the MSB and LSB.
418   EXPECT_TRUE((isShiftedInt<11, 5>(int64_t(0x201) << 5)));
419   EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 3)));
420   EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 6)));
421   EXPECT_TRUE((isShiftedInt<11, 5>(-(int64_t(0x201) << 5))));
422   EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 3))));
423   EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 6))));
424 
425   EXPECT_TRUE((isShiftedInt<6, 10>(-(int64_t(1) << 15))));
426   EXPECT_FALSE((isShiftedInt<6, 10>(int64_t(1) << 15)));
427 }
428 
429 template <typename T>
430 class OverflowTest : public ::testing::Test { };
431 
432 using OverflowTestTypes = ::testing::Types<signed char, short, int, long,
433                                            long long>;
434 
435 TYPED_TEST_SUITE(OverflowTest, OverflowTestTypes, );
436 
437 TYPED_TEST(OverflowTest, AddNoOverflow) {
438   TypeParam Result;
439   EXPECT_FALSE(AddOverflow<TypeParam>(1, 2, Result));
440   EXPECT_EQ(Result, TypeParam(3));
441 }
442 
443 TYPED_TEST(OverflowTest, AddOverflowToNegative) {
444   TypeParam Result;
445   auto MaxValue = std::numeric_limits<TypeParam>::max();
446   EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, MaxValue, Result));
447   EXPECT_EQ(Result, TypeParam(-2));
448 }
449 
450 TYPED_TEST(OverflowTest, AddOverflowToMin) {
451   TypeParam Result;
452   auto MaxValue = std::numeric_limits<TypeParam>::max();
453   EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, TypeParam(1), Result));
454   EXPECT_EQ(Result, std::numeric_limits<TypeParam>::min());
455 }
456 
457 TYPED_TEST(OverflowTest, AddOverflowToZero) {
458   TypeParam Result;
459   auto MinValue = std::numeric_limits<TypeParam>::min();
460   EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, MinValue, Result));
461   EXPECT_EQ(Result, TypeParam(0));
462 }
463 
464 TYPED_TEST(OverflowTest, AddOverflowToMax) {
465   TypeParam Result;
466   auto MinValue = std::numeric_limits<TypeParam>::min();
467   EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, TypeParam(-1), Result));
468   EXPECT_EQ(Result, std::numeric_limits<TypeParam>::max());
469 }
470 
471 TYPED_TEST(OverflowTest, SubNoOverflow) {
472   TypeParam Result;
473   EXPECT_FALSE(SubOverflow<TypeParam>(1, 2, Result));
474   EXPECT_EQ(Result, TypeParam(-1));
475 }
476 
477 TYPED_TEST(OverflowTest, SubOverflowToMax) {
478   TypeParam Result;
479   auto MinValue = std::numeric_limits<TypeParam>::min();
480   EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result));
481   EXPECT_EQ(Result, MinValue);
482 }
483 
484 TYPED_TEST(OverflowTest, SubOverflowToMin) {
485   TypeParam Result;
486   auto MinValue = std::numeric_limits<TypeParam>::min();
487   EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result));
488   EXPECT_EQ(Result, MinValue);
489 }
490 
491 TYPED_TEST(OverflowTest, SubOverflowToNegative) {
492   TypeParam Result;
493   auto MaxValue = std::numeric_limits<TypeParam>::max();
494   auto MinValue = std::numeric_limits<TypeParam>::min();
495   EXPECT_TRUE(SubOverflow<TypeParam>(MaxValue, MinValue, Result));
496   EXPECT_EQ(Result, TypeParam(-1));
497 }
498 
499 TYPED_TEST(OverflowTest, SubOverflowToPositive) {
500   TypeParam Result;
501   auto MaxValue = std::numeric_limits<TypeParam>::max();
502   auto MinValue = std::numeric_limits<TypeParam>::min();
503   EXPECT_TRUE(SubOverflow<TypeParam>(MinValue, MaxValue, Result));
504   EXPECT_EQ(Result, TypeParam(1));
505 }
506 
507 TYPED_TEST(OverflowTest, MulNoOverflow) {
508   TypeParam Result;
509   EXPECT_FALSE(MulOverflow<TypeParam>(1, 2, Result));
510   EXPECT_EQ(Result, 2);
511   EXPECT_FALSE(MulOverflow<TypeParam>(-1, 3, Result));
512   EXPECT_EQ(Result, -3);
513   EXPECT_FALSE(MulOverflow<TypeParam>(4, -2, Result));
514   EXPECT_EQ(Result, -8);
515   EXPECT_FALSE(MulOverflow<TypeParam>(-6, -5, Result));
516   EXPECT_EQ(Result, 30);
517 }
518 
519 TYPED_TEST(OverflowTest, MulNoOverflowToMax) {
520   TypeParam Result;
521   auto MaxValue = std::numeric_limits<TypeParam>::max();
522   auto MinValue = std::numeric_limits<TypeParam>::min();
523   EXPECT_FALSE(MulOverflow<TypeParam>(MinValue + 1, -1, Result));
524   EXPECT_EQ(Result, MaxValue);
525 }
526 
527 TYPED_TEST(OverflowTest, MulOverflowToMin) {
528   TypeParam Result;
529   auto MinValue = std::numeric_limits<TypeParam>::min();
530   EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, -1, Result));
531   EXPECT_EQ(Result, MinValue);
532 }
533 
534 TYPED_TEST(OverflowTest, MulOverflowMax) {
535   TypeParam Result;
536   auto MinValue = std::numeric_limits<TypeParam>::min();
537   auto MaxValue = std::numeric_limits<TypeParam>::max();
538   EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, MinValue, Result));
539   EXPECT_EQ(Result, 0);
540   EXPECT_TRUE(MulOverflow<TypeParam>(MaxValue, MaxValue, Result));
541   EXPECT_EQ(Result, 1);
542 }
543 
544 TYPED_TEST(OverflowTest, MulResultZero) {
545   TypeParam Result;
546   EXPECT_FALSE(MulOverflow<TypeParam>(4, 0, Result));
547   EXPECT_EQ(Result, TypeParam(0));
548   EXPECT_FALSE(MulOverflow<TypeParam>(-5, 0, Result));
549   EXPECT_EQ(Result, TypeParam(0));
550   EXPECT_FALSE(MulOverflow<TypeParam>(0, 5, Result));
551   EXPECT_EQ(Result, TypeParam(0));
552   EXPECT_FALSE(MulOverflow<TypeParam>(0, -5, Result));
553   EXPECT_EQ(Result, TypeParam(0));
554 }
555 
556 } // namespace
557