xref: /llvm-project/llvm/unittests/Support/MathExtrasTest.cpp (revision 4127a69d6c9106cb96a5da30daec7df80fb812d1)
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   EXPECT_TRUE(isIntN(0, 0));
45   EXPECT_FALSE(isIntN(0, 1));
46   EXPECT_FALSE(isIntN(0, -1));
47 }
48 
49 TEST(MathExtras, isUIntN) {
50   EXPECT_TRUE(isUIntN(16, 65535));
51   EXPECT_FALSE(isUIntN(16, 65536));
52   EXPECT_TRUE(isUIntN(1, 0));
53   EXPECT_TRUE(isUIntN(6, 63));
54   EXPECT_TRUE(isUIntN(0, 0));
55   EXPECT_FALSE(isUIntN(0, 1));
56 }
57 
58 TEST(MathExtras, maxIntN) {
59   EXPECT_EQ(32767, maxIntN(16));
60   EXPECT_EQ(2147483647, maxIntN(32));
61   EXPECT_EQ(std::numeric_limits<int32_t>::max(), maxIntN(32));
62   EXPECT_EQ(std::numeric_limits<int64_t>::max(), maxIntN(64));
63   EXPECT_EQ(0, maxIntN(0));
64 }
65 
66 TEST(MathExtras, minIntN) {
67   EXPECT_EQ(-32768LL, minIntN(16));
68   EXPECT_EQ(-64LL, minIntN(7));
69   EXPECT_EQ(std::numeric_limits<int32_t>::min(), minIntN(32));
70   EXPECT_EQ(std::numeric_limits<int64_t>::min(), minIntN(64));
71   EXPECT_EQ(0, minIntN(0));
72 }
73 
74 TEST(MathExtras, maxUIntN) {
75   EXPECT_EQ(0xffffULL, maxUIntN(16));
76   EXPECT_EQ(0xffffffffULL, maxUIntN(32));
77   EXPECT_EQ(0xffffffffffffffffULL, maxUIntN(64));
78   EXPECT_EQ(1ULL, maxUIntN(1));
79   EXPECT_EQ(0x0fULL, maxUIntN(4));
80   EXPECT_EQ(0ULL, maxUIntN(0));
81 }
82 
83 TEST(MathExtras, reverseBits) {
84   uint8_t NZ8 = 42;
85   uint16_t NZ16 = 42;
86   uint32_t NZ32 = 42;
87   uint64_t NZ64 = 42;
88   EXPECT_EQ(0x54ULL, reverseBits(NZ8));
89   EXPECT_EQ(0x5400ULL, reverseBits(NZ16));
90   EXPECT_EQ(0x54000000ULL, reverseBits(NZ32));
91   EXPECT_EQ(0x5400000000000000ULL, reverseBits(NZ64));
92 }
93 
94 TEST(MathExtras, isShiftedMask_32) {
95   EXPECT_FALSE(isShiftedMask_32(0x01010101));
96   EXPECT_TRUE(isShiftedMask_32(0xf0000000));
97   EXPECT_TRUE(isShiftedMask_32(0xffff0000));
98   EXPECT_TRUE(isShiftedMask_32(0xff << 1));
99 
100   unsigned MaskIdx, MaskLen;
101   EXPECT_FALSE(isShiftedMask_32(0x01010101, MaskIdx, MaskLen));
102   EXPECT_TRUE(isShiftedMask_32(0xf0000000, MaskIdx, MaskLen));
103   EXPECT_EQ(28, (int)MaskIdx);
104   EXPECT_EQ(4, (int)MaskLen);
105   EXPECT_TRUE(isShiftedMask_32(0xffff0000, MaskIdx, MaskLen));
106   EXPECT_EQ(16, (int)MaskIdx);
107   EXPECT_EQ(16, (int)MaskLen);
108   EXPECT_TRUE(isShiftedMask_32(0xff << 1, MaskIdx, MaskLen));
109   EXPECT_EQ(1, (int)MaskIdx);
110   EXPECT_EQ(8, (int)MaskLen);
111 }
112 
113 TEST(MathExtras, isShiftedMask_64) {
114   EXPECT_FALSE(isShiftedMask_64(0x0101010101010101ull));
115   EXPECT_TRUE(isShiftedMask_64(0xf000000000000000ull));
116   EXPECT_TRUE(isShiftedMask_64(0xffff000000000000ull));
117   EXPECT_TRUE(isShiftedMask_64(0xffull << 55));
118 
119   unsigned MaskIdx, MaskLen;
120   EXPECT_FALSE(isShiftedMask_64(0x0101010101010101ull, MaskIdx, MaskLen));
121   EXPECT_TRUE(isShiftedMask_64(0xf000000000000000ull, MaskIdx, MaskLen));
122   EXPECT_EQ(60, (int)MaskIdx);
123   EXPECT_EQ(4, (int)MaskLen);
124   EXPECT_TRUE(isShiftedMask_64(0xffff000000000000ull, MaskIdx, MaskLen));
125   EXPECT_EQ(48, (int)MaskIdx);
126   EXPECT_EQ(16, (int)MaskLen);
127   EXPECT_TRUE(isShiftedMask_64(0xffull << 55, MaskIdx, MaskLen));
128   EXPECT_EQ(55, (int)MaskIdx);
129   EXPECT_EQ(8, (int)MaskLen);
130 }
131 
132 TEST(MathExtras, isPowerOf2_32) {
133   EXPECT_FALSE(isPowerOf2_32(0));
134   EXPECT_TRUE(isPowerOf2_32(1 << 6));
135   EXPECT_TRUE(isPowerOf2_32(1 << 12));
136   EXPECT_FALSE(isPowerOf2_32((1 << 19) + 3));
137   EXPECT_FALSE(isPowerOf2_32(0xABCDEF0));
138 }
139 
140 TEST(MathExtras, isPowerOf2_64) {
141   EXPECT_FALSE(isPowerOf2_64(0));
142   EXPECT_TRUE(isPowerOf2_64(1LL << 46));
143   EXPECT_TRUE(isPowerOf2_64(1LL << 12));
144   EXPECT_FALSE(isPowerOf2_64((1LL << 53) + 3));
145   EXPECT_FALSE(isPowerOf2_64(0xABCDEF0ABCDEF0LL));
146 }
147 
148 TEST(MathExtras, PowerOf2Ceil) {
149   EXPECT_EQ(0U, PowerOf2Ceil(0U));
150   EXPECT_EQ(8U, PowerOf2Ceil(8U));
151   EXPECT_EQ(8U, PowerOf2Ceil(7U));
152 }
153 
154 TEST(MathExtras, CTLog2) {
155   EXPECT_EQ(CTLog2<1ULL << 0>(), 0U);
156   EXPECT_EQ(CTLog2<1ULL << 1>(), 1U);
157   EXPECT_EQ(CTLog2<1ULL << 2>(), 2U);
158   EXPECT_EQ(CTLog2<1ULL << 3>(), 3U);
159   EXPECT_EQ(CTLog2<1ULL << 4>(), 4U);
160   EXPECT_EQ(CTLog2<1ULL << 5>(), 5U);
161   EXPECT_EQ(CTLog2<1ULL << 6>(), 6U);
162   EXPECT_EQ(CTLog2<1ULL << 7>(), 7U);
163   EXPECT_EQ(CTLog2<1ULL << 8>(), 8U);
164   EXPECT_EQ(CTLog2<1ULL << 9>(), 9U);
165   EXPECT_EQ(CTLog2<1ULL << 10>(), 10U);
166   EXPECT_EQ(CTLog2<1ULL << 11>(), 11U);
167   EXPECT_EQ(CTLog2<1ULL << 12>(), 12U);
168   EXPECT_EQ(CTLog2<1ULL << 13>(), 13U);
169   EXPECT_EQ(CTLog2<1ULL << 14>(), 14U);
170   EXPECT_EQ(CTLog2<1ULL << 15>(), 15U);
171 }
172 
173 TEST(MathExtras, MinAlign) {
174   EXPECT_EQ(1u, MinAlign(2, 3));
175   EXPECT_EQ(2u, MinAlign(2, 4));
176   EXPECT_EQ(1u, MinAlign(17, 64));
177   EXPECT_EQ(256u, MinAlign(256, 512));
178 }
179 
180 TEST(MathExtras, NextPowerOf2) {
181   EXPECT_EQ(4u, NextPowerOf2(3));
182   EXPECT_EQ(16u, NextPowerOf2(15));
183   EXPECT_EQ(256u, NextPowerOf2(128));
184 }
185 
186 TEST(MathExtras, alignTo) {
187   EXPECT_EQ(8u, alignTo(5, 8));
188   EXPECT_EQ(24u, alignTo(17, 8));
189   EXPECT_EQ(0u, alignTo(~0LL, 8));
190 
191   EXPECT_EQ(7u, alignTo(5, 8, 7));
192   EXPECT_EQ(17u, alignTo(17, 8, 1));
193   EXPECT_EQ(3u, alignTo(~0LL, 8, 3));
194   EXPECT_EQ(552u, alignTo(321, 255, 42));
195 }
196 
197 template <typename T> void SaturatingAddTestHelper() {
198   const T Max = std::numeric_limits<T>::max();
199   bool ResultOverflowed;
200 
201   EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2)));
202   EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2), &ResultOverflowed));
203   EXPECT_FALSE(ResultOverflowed);
204 
205   EXPECT_EQ(Max, SaturatingAdd(Max, T(1)));
206   EXPECT_EQ(Max, SaturatingAdd(Max, T(1), &ResultOverflowed));
207   EXPECT_TRUE(ResultOverflowed);
208 
209   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1)));
210   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 1), &ResultOverflowed));
211   EXPECT_FALSE(ResultOverflowed);
212 
213   EXPECT_EQ(Max, SaturatingAdd(T(1), Max));
214   EXPECT_EQ(Max, SaturatingAdd(T(1), Max, &ResultOverflowed));
215   EXPECT_TRUE(ResultOverflowed);
216 
217   EXPECT_EQ(Max, SaturatingAdd(Max, Max));
218   EXPECT_EQ(Max, SaturatingAdd(Max, Max, &ResultOverflowed));
219   EXPECT_TRUE(ResultOverflowed);
220 
221   EXPECT_EQ(T(6), SaturatingAdd(T(1), T(2), T(3)));
222   EXPECT_EQ(T(6), SaturatingAdd(T(1), T(2), T(3), &ResultOverflowed));
223   EXPECT_FALSE(ResultOverflowed);
224 
225   EXPECT_EQ(T(10), SaturatingAdd(T(1), T(2), T(3), T(4)));
226   EXPECT_EQ(T(10), SaturatingAdd(T(1), T(2), T(3), T(4), &ResultOverflowed));
227   EXPECT_FALSE(ResultOverflowed);
228 
229   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(0)));
230   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(0), &ResultOverflowed));
231   EXPECT_FALSE(ResultOverflowed);
232 
233   EXPECT_EQ(Max, SaturatingAdd(T(0), T(0), Max));
234   EXPECT_EQ(Max, SaturatingAdd(T(0), T(0), Max, &ResultOverflowed));
235   EXPECT_FALSE(ResultOverflowed);
236 
237   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(1)));
238   EXPECT_EQ(Max, SaturatingAdd(Max, T(0), T(1), &ResultOverflowed));
239   EXPECT_TRUE(ResultOverflowed);
240 
241   EXPECT_EQ(Max, SaturatingAdd(T(0), T(1), Max));
242   EXPECT_EQ(Max, SaturatingAdd(T(0), T(1), Max, &ResultOverflowed));
243   EXPECT_TRUE(ResultOverflowed);
244 
245   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 2), T(1)));
246   EXPECT_EQ(Max, SaturatingAdd(T(1), T(Max - 2), T(1), &ResultOverflowed));
247   EXPECT_FALSE(ResultOverflowed);
248 
249   EXPECT_EQ(Max, SaturatingAdd(T(1), T(1), T(Max - 2)));
250   EXPECT_EQ(Max, SaturatingAdd(T(1), T(1), T(Max - 2), &ResultOverflowed));
251   EXPECT_FALSE(ResultOverflowed);
252 
253   EXPECT_EQ(Max, SaturatingAdd(Max, Max, Max));
254   EXPECT_EQ(Max, SaturatingAdd(Max, Max, Max, &ResultOverflowed));
255   EXPECT_TRUE(ResultOverflowed);
256 }
257 
258 TEST(MathExtras, SaturatingAdd) {
259   SaturatingAddTestHelper<uint8_t>();
260   SaturatingAddTestHelper<uint16_t>();
261   SaturatingAddTestHelper<uint32_t>();
262   SaturatingAddTestHelper<uint64_t>();
263 }
264 
265 template<typename T>
266 void SaturatingMultiplyTestHelper()
267 {
268   const T Max = std::numeric_limits<T>::max();
269   bool ResultOverflowed;
270 
271   // Test basic multiplication.
272   EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3)));
273   EXPECT_EQ(T(6), SaturatingMultiply(T(2), T(3), &ResultOverflowed));
274   EXPECT_FALSE(ResultOverflowed);
275 
276   EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2)));
277   EXPECT_EQ(T(6), SaturatingMultiply(T(3), T(2), &ResultOverflowed));
278   EXPECT_FALSE(ResultOverflowed);
279 
280   // Test multiplication by zero.
281   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0)));
282   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(0), &ResultOverflowed));
283   EXPECT_FALSE(ResultOverflowed);
284 
285   EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0)));
286   EXPECT_EQ(T(0), SaturatingMultiply(T(1), T(0), &ResultOverflowed));
287   EXPECT_FALSE(ResultOverflowed);
288 
289   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1)));
290   EXPECT_EQ(T(0), SaturatingMultiply(T(0), T(1), &ResultOverflowed));
291   EXPECT_FALSE(ResultOverflowed);
292 
293   EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0)));
294   EXPECT_EQ(T(0), SaturatingMultiply(Max, T(0), &ResultOverflowed));
295   EXPECT_FALSE(ResultOverflowed);
296 
297   EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max));
298   EXPECT_EQ(T(0), SaturatingMultiply(T(0), Max, &ResultOverflowed));
299   EXPECT_FALSE(ResultOverflowed);
300 
301   // Test multiplication by maximum value.
302   EXPECT_EQ(Max, SaturatingMultiply(Max, T(2)));
303   EXPECT_EQ(Max, SaturatingMultiply(Max, T(2), &ResultOverflowed));
304   EXPECT_TRUE(ResultOverflowed);
305 
306   EXPECT_EQ(Max, SaturatingMultiply(T(2), Max));
307   EXPECT_EQ(Max, SaturatingMultiply(T(2), Max, &ResultOverflowed));
308   EXPECT_TRUE(ResultOverflowed);
309 
310   EXPECT_EQ(Max, SaturatingMultiply(Max, Max));
311   EXPECT_EQ(Max, SaturatingMultiply(Max, Max, &ResultOverflowed));
312   EXPECT_TRUE(ResultOverflowed);
313 
314   // Test interesting boundary conditions for algorithm -
315   // ((1 << A) - 1) * ((1 << B) + K) for K in [-1, 0, 1]
316   // and A + B == std::numeric_limits<T>::digits.
317   // We expect overflow iff A > B and K = 1.
318   const int Digits = std::numeric_limits<T>::digits;
319   for (int A = 1, B = Digits - 1; B >= 1; ++A, --B) {
320     for (int K = -1; K <= 1; ++K) {
321       T X = (T(1) << A) - T(1);
322       T Y = (T(1) << B) + K;
323       bool OverflowExpected = A > B && K == 1;
324 
325       if(OverflowExpected) {
326         EXPECT_EQ(Max, SaturatingMultiply(X, Y));
327         EXPECT_EQ(Max, SaturatingMultiply(X, Y, &ResultOverflowed));
328         EXPECT_TRUE(ResultOverflowed);
329       } else {
330         EXPECT_EQ(X * Y, SaturatingMultiply(X, Y));
331         EXPECT_EQ(X * Y, SaturatingMultiply(X, Y, &ResultOverflowed));
332         EXPECT_FALSE(ResultOverflowed);
333       }
334     }
335   }
336 }
337 
338 TEST(MathExtras, SaturatingMultiply) {
339   SaturatingMultiplyTestHelper<uint8_t>();
340   SaturatingMultiplyTestHelper<uint16_t>();
341   SaturatingMultiplyTestHelper<uint32_t>();
342   SaturatingMultiplyTestHelper<uint64_t>();
343 }
344 
345 template<typename T>
346 void SaturatingMultiplyAddTestHelper()
347 {
348   const T Max = std::numeric_limits<T>::max();
349   bool ResultOverflowed;
350 
351   // Test basic multiply-add.
352   EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10)));
353   EXPECT_EQ(T(16), SaturatingMultiplyAdd(T(2), T(3), T(10), &ResultOverflowed));
354   EXPECT_FALSE(ResultOverflowed);
355 
356   // Test multiply overflows, add doesn't overflow
357   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(0), &ResultOverflowed));
358   EXPECT_TRUE(ResultOverflowed);
359 
360   // Test multiply doesn't overflow, add overflows
361   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed));
362   EXPECT_TRUE(ResultOverflowed);
363 
364   // Test multiply-add with Max as operand
365   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), T(1), Max, &ResultOverflowed));
366   EXPECT_TRUE(ResultOverflowed);
367 
368   EXPECT_EQ(Max, SaturatingMultiplyAdd(T(1), Max, T(1), &ResultOverflowed));
369   EXPECT_TRUE(ResultOverflowed);
370 
371   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, T(1), &ResultOverflowed));
372   EXPECT_TRUE(ResultOverflowed);
373 
374   EXPECT_EQ(Max, SaturatingMultiplyAdd(Max, Max, Max, &ResultOverflowed));
375   EXPECT_TRUE(ResultOverflowed);
376 
377   // Test multiply-add with 0 as operand
378   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(1), T(0), &ResultOverflowed));
379   EXPECT_FALSE(ResultOverflowed);
380 
381   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(1), T(0), T(1), &ResultOverflowed));
382   EXPECT_FALSE(ResultOverflowed);
383 
384   EXPECT_EQ(T(1), SaturatingMultiplyAdd(T(0), T(0), T(1), &ResultOverflowed));
385   EXPECT_FALSE(ResultOverflowed);
386 
387   EXPECT_EQ(T(0), SaturatingMultiplyAdd(T(0), T(0), T(0), &ResultOverflowed));
388   EXPECT_FALSE(ResultOverflowed);
389 
390 }
391 
392 TEST(MathExtras, SaturatingMultiplyAdd) {
393   SaturatingMultiplyAddTestHelper<uint8_t>();
394   SaturatingMultiplyAddTestHelper<uint16_t>();
395   SaturatingMultiplyAddTestHelper<uint32_t>();
396   SaturatingMultiplyAddTestHelper<uint64_t>();
397 }
398 
399 TEST(MathExtras, IsShiftedUInt) {
400   EXPECT_TRUE((isShiftedUInt<1, 0>(0)));
401   EXPECT_TRUE((isShiftedUInt<1, 0>(1)));
402   EXPECT_FALSE((isShiftedUInt<1, 0>(2)));
403   EXPECT_FALSE((isShiftedUInt<1, 0>(3)));
404   EXPECT_FALSE((isShiftedUInt<1, 0>(0x8000000000000000)));
405   EXPECT_TRUE((isShiftedUInt<1, 63>(0x8000000000000000)));
406   EXPECT_TRUE((isShiftedUInt<2, 62>(0xC000000000000000)));
407   EXPECT_FALSE((isShiftedUInt<2, 62>(0xE000000000000000)));
408 
409   // 0x201 is ten bits long and has a 1 in the MSB and LSB.
410   EXPECT_TRUE((isShiftedUInt<10, 5>(uint64_t(0x201) << 5)));
411   EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 4)));
412   EXPECT_FALSE((isShiftedUInt<10, 5>(uint64_t(0x201) << 6)));
413 }
414 
415 TEST(MathExtras, IsShiftedInt) {
416   EXPECT_TRUE((isShiftedInt<1, 0>(0)));
417   EXPECT_TRUE((isShiftedInt<1, 0>(-1)));
418   EXPECT_FALSE((isShiftedInt<1, 0>(2)));
419   EXPECT_FALSE((isShiftedInt<1, 0>(3)));
420   EXPECT_FALSE((isShiftedInt<1, 0>(0x8000000000000000)));
421   EXPECT_TRUE((isShiftedInt<1, 63>(0x8000000000000000)));
422   EXPECT_TRUE((isShiftedInt<2, 62>(0xC000000000000000)));
423   EXPECT_FALSE((isShiftedInt<2, 62>(0xE000000000000000)));
424 
425   // 0x201 is ten bits long and has a 1 in the MSB and LSB.
426   EXPECT_TRUE((isShiftedInt<11, 5>(int64_t(0x201) << 5)));
427   EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 3)));
428   EXPECT_FALSE((isShiftedInt<11, 5>(int64_t(0x201) << 6)));
429   EXPECT_TRUE((isShiftedInt<11, 5>(-(int64_t(0x201) << 5))));
430   EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 3))));
431   EXPECT_FALSE((isShiftedInt<11, 5>(-(int64_t(0x201) << 6))));
432 
433   EXPECT_TRUE((isShiftedInt<6, 10>(-(int64_t(1) << 15))));
434   EXPECT_FALSE((isShiftedInt<6, 10>(int64_t(1) << 15)));
435 }
436 
437 template <typename T>
438 class OverflowTest : public ::testing::Test { };
439 
440 using OverflowTestTypes = ::testing::Types<signed char, short, int, long,
441                                            long long>;
442 
443 TYPED_TEST_SUITE(OverflowTest, OverflowTestTypes, );
444 
445 TYPED_TEST(OverflowTest, AddNoOverflow) {
446   TypeParam Result;
447   EXPECT_FALSE(AddOverflow<TypeParam>(1, 2, Result));
448   EXPECT_EQ(Result, TypeParam(3));
449 }
450 
451 TYPED_TEST(OverflowTest, AddOverflowToNegative) {
452   TypeParam Result;
453   auto MaxValue = std::numeric_limits<TypeParam>::max();
454   EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, MaxValue, Result));
455   EXPECT_EQ(Result, TypeParam(-2));
456 }
457 
458 TYPED_TEST(OverflowTest, AddOverflowToMin) {
459   TypeParam Result;
460   auto MaxValue = std::numeric_limits<TypeParam>::max();
461   EXPECT_TRUE(AddOverflow<TypeParam>(MaxValue, TypeParam(1), Result));
462   EXPECT_EQ(Result, std::numeric_limits<TypeParam>::min());
463 }
464 
465 TYPED_TEST(OverflowTest, AddOverflowToZero) {
466   TypeParam Result;
467   auto MinValue = std::numeric_limits<TypeParam>::min();
468   EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, MinValue, Result));
469   EXPECT_EQ(Result, TypeParam(0));
470 }
471 
472 TYPED_TEST(OverflowTest, AddOverflowToMax) {
473   TypeParam Result;
474   auto MinValue = std::numeric_limits<TypeParam>::min();
475   EXPECT_TRUE(AddOverflow<TypeParam>(MinValue, TypeParam(-1), Result));
476   EXPECT_EQ(Result, std::numeric_limits<TypeParam>::max());
477 }
478 
479 TYPED_TEST(OverflowTest, SubNoOverflow) {
480   TypeParam Result;
481   EXPECT_FALSE(SubOverflow<TypeParam>(1, 2, Result));
482   EXPECT_EQ(Result, TypeParam(-1));
483 }
484 
485 TYPED_TEST(OverflowTest, SubOverflowToMax) {
486   TypeParam Result;
487   auto MinValue = std::numeric_limits<TypeParam>::min();
488   EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result));
489   EXPECT_EQ(Result, MinValue);
490 }
491 
492 TYPED_TEST(OverflowTest, SubOverflowToMin) {
493   TypeParam Result;
494   auto MinValue = std::numeric_limits<TypeParam>::min();
495   EXPECT_TRUE(SubOverflow<TypeParam>(0, MinValue, Result));
496   EXPECT_EQ(Result, MinValue);
497 }
498 
499 TYPED_TEST(OverflowTest, SubOverflowToNegative) {
500   TypeParam Result;
501   auto MaxValue = std::numeric_limits<TypeParam>::max();
502   auto MinValue = std::numeric_limits<TypeParam>::min();
503   EXPECT_TRUE(SubOverflow<TypeParam>(MaxValue, MinValue, Result));
504   EXPECT_EQ(Result, TypeParam(-1));
505 }
506 
507 TYPED_TEST(OverflowTest, SubOverflowToPositive) {
508   TypeParam Result;
509   auto MaxValue = std::numeric_limits<TypeParam>::max();
510   auto MinValue = std::numeric_limits<TypeParam>::min();
511   EXPECT_TRUE(SubOverflow<TypeParam>(MinValue, MaxValue, Result));
512   EXPECT_EQ(Result, TypeParam(1));
513 }
514 
515 TYPED_TEST(OverflowTest, MulNoOverflow) {
516   TypeParam Result;
517   EXPECT_FALSE(MulOverflow<TypeParam>(1, 2, Result));
518   EXPECT_EQ(Result, 2);
519   EXPECT_FALSE(MulOverflow<TypeParam>(-1, 3, Result));
520   EXPECT_EQ(Result, -3);
521   EXPECT_FALSE(MulOverflow<TypeParam>(4, -2, Result));
522   EXPECT_EQ(Result, -8);
523   EXPECT_FALSE(MulOverflow<TypeParam>(-6, -5, Result));
524   EXPECT_EQ(Result, 30);
525 }
526 
527 TYPED_TEST(OverflowTest, MulNoOverflowToMax) {
528   TypeParam Result;
529   auto MaxValue = std::numeric_limits<TypeParam>::max();
530   auto MinValue = std::numeric_limits<TypeParam>::min();
531   EXPECT_FALSE(MulOverflow<TypeParam>(MinValue + 1, -1, Result));
532   EXPECT_EQ(Result, MaxValue);
533 }
534 
535 TYPED_TEST(OverflowTest, MulOverflowToMin) {
536   TypeParam Result;
537   auto MinValue = std::numeric_limits<TypeParam>::min();
538   EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, -1, Result));
539   EXPECT_EQ(Result, MinValue);
540 }
541 
542 TYPED_TEST(OverflowTest, MulOverflowMax) {
543   TypeParam Result;
544   auto MinValue = std::numeric_limits<TypeParam>::min();
545   auto MaxValue = std::numeric_limits<TypeParam>::max();
546   EXPECT_TRUE(MulOverflow<TypeParam>(MinValue, MinValue, Result));
547   EXPECT_EQ(Result, 0);
548   EXPECT_TRUE(MulOverflow<TypeParam>(MaxValue, MaxValue, Result));
549   EXPECT_EQ(Result, 1);
550 }
551 
552 TYPED_TEST(OverflowTest, MulResultZero) {
553   TypeParam Result;
554   EXPECT_FALSE(MulOverflow<TypeParam>(4, 0, Result));
555   EXPECT_EQ(Result, TypeParam(0));
556   EXPECT_FALSE(MulOverflow<TypeParam>(-5, 0, Result));
557   EXPECT_EQ(Result, TypeParam(0));
558   EXPECT_FALSE(MulOverflow<TypeParam>(0, 5, Result));
559   EXPECT_EQ(Result, TypeParam(0));
560   EXPECT_FALSE(MulOverflow<TypeParam>(0, -5, Result));
561   EXPECT_EQ(Result, TypeParam(0));
562 }
563 
564 } // namespace
565