xref: /llvm-project/llvm/unittests/Support/MathExtrasTest.cpp (revision b49b429fde3a282664289d7a2155d994085eb232)
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, FloatBits) {
166   static const float kValue = 5632.34f;
167   EXPECT_FLOAT_EQ(kValue, BitsToFloat(FloatToBits(kValue)));
168 }
169 
170 TEST(MathExtras, DoubleBits) {
171   static const double kValue = 87987234.983498;
172   EXPECT_DOUBLE_EQ(kValue, BitsToDouble(DoubleToBits(kValue)));
173 }
174 
175 TEST(MathExtras, MinAlign) {
176   EXPECT_EQ(1u, MinAlign(2, 3));
177   EXPECT_EQ(2u, MinAlign(2, 4));
178   EXPECT_EQ(1u, MinAlign(17, 64));
179   EXPECT_EQ(256u, MinAlign(256, 512));
180 }
181 
182 TEST(MathExtras, NextPowerOf2) {
183   EXPECT_EQ(4u, NextPowerOf2(3));
184   EXPECT_EQ(16u, NextPowerOf2(15));
185   EXPECT_EQ(256u, NextPowerOf2(128));
186 }
187 
188 TEST(MathExtras, alignTo) {
189   EXPECT_EQ(8u, alignTo(5, 8));
190   EXPECT_EQ(24u, alignTo(17, 8));
191   EXPECT_EQ(0u, alignTo(~0LL, 8));
192 
193   EXPECT_EQ(7u, alignTo(5, 8, 7));
194   EXPECT_EQ(17u, alignTo(17, 8, 1));
195   EXPECT_EQ(3u, alignTo(~0LL, 8, 3));
196   EXPECT_EQ(552u, alignTo(321, 255, 42));
197 }
198 
199 template <typename T> void SaturatingAddTestHelper() {
200   const T Max = std::numeric_limits<T>::max();
201   bool ResultOverflowed;
202 
203   EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2)));
204   EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2), &ResultOverflowed));
205   EXPECT_FALSE(ResultOverflowed);
206 
207   EXPECT_EQ(Max, SaturatingAdd(Max, T(1)));
208   EXPECT_EQ(Max, SaturatingAdd(Max, T(1), &ResultOverflowed));
209   EXPECT_TRUE(ResultOverflowed);
210 
211   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1)));
212   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1), &ResultOverflowed));
213   EXPECT_FALSE(ResultOverflowed);
214 
215   EXPECT_EQ(Max, SaturatingAdd(T(1), Max));
216   EXPECT_EQ(Max, SaturatingAdd(T(1), Max, &ResultOverflowed));
217   EXPECT_TRUE(ResultOverflowed);
218 
219   EXPECT_EQ(Max, SaturatingAdd(Max, Max));
220   EXPECT_EQ(Max, SaturatingAdd(Max, Max, &ResultOverflowed));
221   EXPECT_TRUE(ResultOverflowed);
222 
223   EXPECT_EQ(T(6), SaturatingAdd(T(1), T(2), T(3)));
224   EXPECT_EQ(T(6), SaturatingAdd(T(1), T(2), T(3), &ResultOverflowed));
225   EXPECT_FALSE(ResultOverflowed);
226 
227   EXPECT_EQ(T(10), SaturatingAdd(T(1), T(2), T(3), T(4)));
228   EXPECT_EQ(T(10), SaturatingAdd(T(1), T(2), T(3), T(4), &ResultOverflowed));
229   EXPECT_FALSE(ResultOverflowed);
230 
231   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(0)));
232   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(0), &ResultOverflowed));
233   EXPECT_FALSE(ResultOverflowed);
234 
235   EXPECT_EQ(Max, SaturatingAdd(T(0), T(0), Max));
236   EXPECT_EQ(Max, SaturatingAdd(T(0), T(0), Max, &ResultOverflowed));
237   EXPECT_FALSE(ResultOverflowed);
238 
239   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(1)));
240   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(1), &ResultOverflowed));
241   EXPECT_TRUE(ResultOverflowed);
242 
243   EXPECT_EQ(Max, SaturatingAdd(T(0), T(1), Max));
244   EXPECT_EQ(Max, SaturatingAdd(T(0), T(1), Max, &ResultOverflowed));
245   EXPECT_TRUE(ResultOverflowed);
246 
247   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 2), T(1)));
248   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 2), T(1), &ResultOverflowed));
249   EXPECT_FALSE(ResultOverflowed);
250 
251   EXPECT_EQ(Max, SaturatingAdd(T(1), T(1), T(Max - 2)));
252   EXPECT_EQ(Max, SaturatingAdd(T(1), T(1), T(Max - 2), &ResultOverflowed));
253   EXPECT_FALSE(ResultOverflowed);
254 
255   EXPECT_EQ(Max, SaturatingAdd(Max, Max, Max));
256   EXPECT_EQ(Max, SaturatingAdd(Max, Max, Max, &ResultOverflowed));
257   EXPECT_TRUE(ResultOverflowed);
258 }
259 
260 TEST(MathExtras, SaturatingAdd) {
261   SaturatingAddTestHelper<uint8_t>();
262   SaturatingAddTestHelper<uint16_t>();
263   SaturatingAddTestHelper<uint32_t>();
264   SaturatingAddTestHelper<uint64_t>();
265 }
266 
267 template<typename T>
268 void SaturatingMultiplyTestHelper()
269 {
270   const T Max = std::numeric_limits<T>::max();
271   bool ResultOverflowed;
272 
273   // Test basic multiplication.
274   EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3)));
275   EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3), &ResultOverflowed));
276   EXPECT_FALSE(ResultOverflowed);
277 
278   EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2)));
279   EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2), &ResultOverflowed));
280   EXPECT_FALSE(ResultOverflowed);
281 
282   // Test multiplication by zero.
283   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0)));
284   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0), &ResultOverflowed));
285   EXPECT_FALSE(ResultOverflowed);
286 
287   EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0)));
288   EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0), &ResultOverflowed));
289   EXPECT_FALSE(ResultOverflowed);
290 
291   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1)));
292   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1), &ResultOverflowed));
293   EXPECT_FALSE(ResultOverflowed);
294 
295   EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0)));
296   EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0), &ResultOverflowed));
297   EXPECT_FALSE(ResultOverflowed);
298 
299   EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max));
300   EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max, &ResultOverflowed));
301   EXPECT_FALSE(ResultOverflowed);
302 
303   // Test multiplication by maximum value.
304   EXPECT_EQ(Max, SaturatingMultiply(Max, T(2)));
305   EXPECT_EQ(Max, SaturatingMultiply(Max, T(2), &ResultOverflowed));
306   EXPECT_TRUE(ResultOverflowed);
307 
308   EXPECT_EQ(Max, SaturatingMultiply(T(2), Max));
309   EXPECT_EQ(Max, SaturatingMultiply(T(2), Max, &ResultOverflowed));
310   EXPECT_TRUE(ResultOverflowed);
311 
312   EXPECT_EQ(Max, SaturatingMultiply(Max, Max));
313   EXPECT_EQ(Max, SaturatingMultiply(Max, Max, &ResultOverflowed));
314   EXPECT_TRUE(ResultOverflowed);
315 
316   // Test interesting boundary conditions for algorithm -
317   // ((1 << A) - 1) * ((1 << B) + K) for K in [-1, 0, 1]
318   // and A + B == std::numeric_limits<T>::digits.
319   // We expect overflow iff A > B and K = 1.
320   const int Digits = std::numeric_limits<T>::digits;
321   for (int A = 1, B = Digits - 1; B >= 1; ++A, --B) {
322     for (int K = -1; K <= 1; ++K) {
323       T X = (T(1) << A) - T(1);
324       T Y = (T(1) << B) + K;
325       bool OverflowExpected = A > B && K == 1;
326 
327       if(OverflowExpected) {
328         EXPECT_EQ(Max, SaturatingMultiply(X, Y));
329         EXPECT_EQ(Max, SaturatingMultiply(X, Y, &ResultOverflowed));
330         EXPECT_TRUE(ResultOverflowed);
331       } else {
332         EXPECT_EQ(X * Y, SaturatingMultiply(X, Y));
333         EXPECT_EQ(X * Y, SaturatingMultiply(X, Y, &ResultOverflowed));
334         EXPECT_FALSE(ResultOverflowed);
335       }
336     }
337   }
338 }
339 
340 TEST(MathExtras, SaturatingMultiply) {
341   SaturatingMultiplyTestHelper<uint8_t>();
342   SaturatingMultiplyTestHelper<uint16_t>();
343   SaturatingMultiplyTestHelper<uint32_t>();
344   SaturatingMultiplyTestHelper<uint64_t>();
345 }
346 
347 template<typename T>
348 void SaturatingMultiplyAddTestHelper()
349 {
350   const T Max = std::numeric_limits<T>::max();
351   bool ResultOverflowed;
352 
353   // Test basic multiply-add.
354   EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10)));
355   EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10), &ResultOverflowed));
356   EXPECT_FALSE(ResultOverflowed);
357 
358   // Test multiply overflows, add doesn't overflow
359   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(0), &ResultOverflowed));
360   EXPECT_TRUE(ResultOverflowed);
361 
362   // Test multiply doesn't overflow, add overflows
363   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed));
364   EXPECT_TRUE(ResultOverflowed);
365 
366   // Test multiply-add with Max as operand
367   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed));
368   EXPECT_TRUE(ResultOverflowed);
369 
370   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), Max, T(1), &ResultOverflowed));
371   EXPECT_TRUE(ResultOverflowed);
372 
373   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(1), &ResultOverflowed));
374   EXPECT_TRUE(ResultOverflowed);
375 
376   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, Max, &ResultOverflowed));
377   EXPECT_TRUE(ResultOverflowed);
378 
379   // Test multiply-add with 0 as operand
380   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(1), T(0), &ResultOverflowed));
381   EXPECT_FALSE(ResultOverflowed);
382 
383   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(0), T(1), &ResultOverflowed));
384   EXPECT_FALSE(ResultOverflowed);
385 
386   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(0), T(0), T(1), &ResultOverflowed));
387   EXPECT_FALSE(ResultOverflowed);
388 
389   EXPECT_EQ(T(0), SaturatingMultiplyAdd(T(0), T(0), T(0), &ResultOverflowed));
390   EXPECT_FALSE(ResultOverflowed);
391 
392 }
393 
394 TEST(MathExtras, SaturatingMultiplyAdd) {
395   SaturatingMultiplyAddTestHelper<uint8_t>();
396   SaturatingMultiplyAddTestHelper<uint16_t>();
397   SaturatingMultiplyAddTestHelper<uint32_t>();
398   SaturatingMultiplyAddTestHelper<uint64_t>();
399 }
400 
401 TEST(MathExtras, IsShiftedUInt) {
402   EXPECT_TRUE((isShiftedUInt<1, 0>(0)));
403   EXPECT_TRUE((isShiftedUInt<1, 0>(1)));
404   EXPECT_FALSE((isShiftedUInt<1, 0>(2)));
405   EXPECT_FALSE((isShiftedUInt<1, 0>(3)));
406   EXPECT_FALSE((isShiftedUInt<1, 0>(0x8000000000000000)));
407   EXPECT_TRUE((isShiftedUInt<1, 63>(0x8000000000000000)));
408   EXPECT_TRUE((isShiftedUInt<2, 62>(0xC000000000000000)));
409   EXPECT_FALSE((isShiftedUInt<2, 62>(0xE000000000000000)));
410 
411   // 0x201 is ten bits long and has a 1 in the MSB and LSB.
412   EXPECT_TRUE((isShiftedUInt<10, 5>(uint64_t(0x201) << 5)));
413   EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 4)));
414   EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 6)));
415 }
416 
417 TEST(MathExtras, IsShiftedInt) {
418   EXPECT_TRUE((isShiftedInt<1, 0>(0)));
419   EXPECT_TRUE((isShiftedInt<1, 0>(-1)));
420   EXPECT_FALSE((isShiftedInt<1, 0>(2)));
421   EXPECT_FALSE((isShiftedInt<1, 0>(3)));
422   EXPECT_FALSE((isShiftedInt<1, 0>(0x8000000000000000)));
423   EXPECT_TRUE((isShiftedInt<1, 63>(0x8000000000000000)));
424   EXPECT_TRUE((isShiftedInt<2, 62>(0xC000000000000000)));
425   EXPECT_FALSE((isShiftedInt<2, 62>(0xE000000000000000)));
426 
427   // 0x201 is ten bits long and has a 1 in the MSB and LSB.
428   EXPECT_TRUE((isShiftedInt<11, 5>(int64_t(0x201) << 5)));
429   EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 3)));
430   EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 6)));
431   EXPECT_TRUE((isShiftedInt<11, 5>(-(int64_t(0x201) << 5))));
432   EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 3))));
433   EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 6))));
434 
435   EXPECT_TRUE((isShiftedInt<6, 10>(-(int64_t(1) << 15))));
436   EXPECT_FALSE((isShiftedInt<6, 10>(int64_t(1) << 15)));
437 }
438 
439 template <typename T>
440 class OverflowTest : public ::testing::Test { };
441 
442 using OverflowTestTypes = ::testing::Types<signed char, short, int, long,
443                                            long long>;
444 
445 TYPED_TEST_SUITE(OverflowTest, OverflowTestTypes, );
446 
447 TYPED_TEST(OverflowTest, AddNoOverflow) {
448   TypeParam Result;
449   EXPECT_FALSE(AddOverflow<TypeParam>(1, 2, Result));
450   EXPECT_EQ(Result, TypeParam(3));
451 }
452 
453 TYPED_TEST(OverflowTest, AddOverflowToNegative) {
454   TypeParam Result;
455   auto MaxValue = std::numeric_limits<TypeParam>::max();
456   EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, MaxValue, Result));
457   EXPECT_EQ(Result, TypeParam(-2));
458 }
459 
460 TYPED_TEST(OverflowTest, AddOverflowToMin) {
461   TypeParam Result;
462   auto MaxValue = std::numeric_limits<TypeParam>::max();
463   EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, TypeParam(1), Result));
464   EXPECT_EQ(Result, std::numeric_limits<TypeParam>::min());
465 }
466 
467 TYPED_TEST(OverflowTest, AddOverflowToZero) {
468   TypeParam Result;
469   auto MinValue = std::numeric_limits<TypeParam>::min();
470   EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, MinValue, Result));
471   EXPECT_EQ(Result, TypeParam(0));
472 }
473 
474 TYPED_TEST(OverflowTest, AddOverflowToMax) {
475   TypeParam Result;
476   auto MinValue = std::numeric_limits<TypeParam>::min();
477   EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, TypeParam(-1), Result));
478   EXPECT_EQ(Result, std::numeric_limits<TypeParam>::max());
479 }
480 
481 TYPED_TEST(OverflowTest, SubNoOverflow) {
482   TypeParam Result;
483   EXPECT_FALSE(SubOverflow<TypeParam>(1, 2, Result));
484   EXPECT_EQ(Result, TypeParam(-1));
485 }
486 
487 TYPED_TEST(OverflowTest, SubOverflowToMax) {
488   TypeParam Result;
489   auto MinValue = std::numeric_limits<TypeParam>::min();
490   EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result));
491   EXPECT_EQ(Result, MinValue);
492 }
493 
494 TYPED_TEST(OverflowTest, SubOverflowToMin) {
495   TypeParam Result;
496   auto MinValue = std::numeric_limits<TypeParam>::min();
497   EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result));
498   EXPECT_EQ(Result, MinValue);
499 }
500 
501 TYPED_TEST(OverflowTest, SubOverflowToNegative) {
502   TypeParam Result;
503   auto MaxValue = std::numeric_limits<TypeParam>::max();
504   auto MinValue = std::numeric_limits<TypeParam>::min();
505   EXPECT_TRUE(SubOverflow<TypeParam>(MaxValue, MinValue, Result));
506   EXPECT_EQ(Result, TypeParam(-1));
507 }
508 
509 TYPED_TEST(OverflowTest, SubOverflowToPositive) {
510   TypeParam Result;
511   auto MaxValue = std::numeric_limits<TypeParam>::max();
512   auto MinValue = std::numeric_limits<TypeParam>::min();
513   EXPECT_TRUE(SubOverflow<TypeParam>(MinValue, MaxValue, Result));
514   EXPECT_EQ(Result, TypeParam(1));
515 }
516 
517 TYPED_TEST(OverflowTest, MulNoOverflow) {
518   TypeParam Result;
519   EXPECT_FALSE(MulOverflow<TypeParam>(1, 2, Result));
520   EXPECT_EQ(Result, 2);
521   EXPECT_FALSE(MulOverflow<TypeParam>(-1, 3, Result));
522   EXPECT_EQ(Result, -3);
523   EXPECT_FALSE(MulOverflow<TypeParam>(4, -2, Result));
524   EXPECT_EQ(Result, -8);
525   EXPECT_FALSE(MulOverflow<TypeParam>(-6, -5, Result));
526   EXPECT_EQ(Result, 30);
527 }
528 
529 TYPED_TEST(OverflowTest, MulNoOverflowToMax) {
530   TypeParam Result;
531   auto MaxValue = std::numeric_limits<TypeParam>::max();
532   auto MinValue = std::numeric_limits<TypeParam>::min();
533   EXPECT_FALSE(MulOverflow<TypeParam>(MinValue + 1, -1, Result));
534   EXPECT_EQ(Result, MaxValue);
535 }
536 
537 TYPED_TEST(OverflowTest, MulOverflowToMin) {
538   TypeParam Result;
539   auto MinValue = std::numeric_limits<TypeParam>::min();
540   EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, -1, Result));
541   EXPECT_EQ(Result, MinValue);
542 }
543 
544 TYPED_TEST(OverflowTest, MulOverflowMax) {
545   TypeParam Result;
546   auto MinValue = std::numeric_limits<TypeParam>::min();
547   auto MaxValue = std::numeric_limits<TypeParam>::max();
548   EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, MinValue, Result));
549   EXPECT_EQ(Result, 0);
550   EXPECT_TRUE(MulOverflow<TypeParam>(MaxValue, MaxValue, Result));
551   EXPECT_EQ(Result, 1);
552 }
553 
554 TYPED_TEST(OverflowTest, MulResultZero) {
555   TypeParam Result;
556   EXPECT_FALSE(MulOverflow<TypeParam>(4, 0, Result));
557   EXPECT_EQ(Result, TypeParam(0));
558   EXPECT_FALSE(MulOverflow<TypeParam>(-5, 0, Result));
559   EXPECT_EQ(Result, TypeParam(0));
560   EXPECT_FALSE(MulOverflow<TypeParam>(0, 5, Result));
561   EXPECT_EQ(Result, TypeParam(0));
562   EXPECT_FALSE(MulOverflow<TypeParam>(0, -5, Result));
563   EXPECT_EQ(Result, TypeParam(0));
564 }
565 
566 } // namespace
567