xref: /llvm-project/llvm/unittests/Support/AlignmentTest.cpp (revision 17e68156f644906207eed23fda3998065123f47a)
1 //=== - llvm/unittest/Support/Alignment.cpp - Alignment utility 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/Alignment.h"
10 #include "gtest/gtest.h"
11 
12 #include <vector>
13 
14 #ifdef _MSC_VER
15 // Disable warnings about potential divide by 0.
16 #pragma warning(push)
17 #pragma warning(disable : 4723)
18 #endif
19 
20 using namespace llvm;
21 
22 namespace {
23 
24 TEST(AlignmentTest, AlignOfConstant) {
25   EXPECT_EQ(Align::Of<uint8_t>(), Align(alignof(uint8_t)));
26   EXPECT_EQ(Align::Of<uint16_t>(), Align(alignof(uint16_t)));
27   EXPECT_EQ(Align::Of<uint32_t>(), Align(alignof(uint32_t)));
28   EXPECT_EQ(Align::Of<uint64_t>(), Align(alignof(uint64_t)));
29 }
30 
31 TEST(AlignmentTest, AlignConstant) {
32   EXPECT_EQ(Align::Constant<1>(), Align(1));
33   EXPECT_EQ(Align::Constant<2>(), Align(2));
34   EXPECT_EQ(Align::Constant<4>(), Align(4));
35   EXPECT_EQ(Align::Constant<8>(), Align(8));
36   EXPECT_EQ(Align::Constant<16>(), Align(16));
37   EXPECT_EQ(Align::Constant<32>(), Align(32));
38   EXPECT_EQ(Align::Constant<64>(), Align(64));
39 }
40 
41 TEST(AlignmentTest, AlignConstexprConstant) {
42   constexpr Align kConstantAlign = Align::Of<uint64_t>();
43   EXPECT_EQ(Align(alignof(uint64_t)), kConstantAlign);
44 }
45 
46 std::vector<uint64_t> getValidAlignments() {
47   std::vector<uint64_t> Out;
48   for (size_t Shift = 0; Shift < 64; ++Shift)
49     Out.push_back(1ULL << Shift);
50   return Out;
51 }
52 
53 TEST(AlignmentTest, AlignDefaultCTor) {
54   EXPECT_EQ(Align().value(), 1ULL);
55 }
56 
57 TEST(AlignmentTest, MaybeAlignDefaultCTor) {
58   EXPECT_FALSE(MaybeAlign().hasValue());
59 }
60 
61 TEST(AlignmentTest, ValidCTors) {
62   for (uint64_t Value : getValidAlignments()) {
63     EXPECT_EQ(Align(Value).value(), Value);
64     EXPECT_EQ((*MaybeAlign(Value)).value(), Value);
65   }
66 }
67 
68 TEST(AlignmentTest, CheckMaybeAlignHasValue) {
69   EXPECT_TRUE(MaybeAlign(1));
70   EXPECT_TRUE(MaybeAlign(1).hasValue());
71   EXPECT_FALSE(MaybeAlign(0));
72   EXPECT_FALSE(MaybeAlign(0).hasValue());
73   EXPECT_FALSE(MaybeAlign());
74   EXPECT_FALSE(MaybeAlign().hasValue());
75 }
76 
77 TEST(AlignmentTest, Division) {
78   for (uint64_t Value : getValidAlignments()) {
79     if (Value > 1) {
80       EXPECT_EQ(Align(Value) / 2, Value / 2);
81     }
82   }
83 }
84 
85 TEST(AlignmentTest, AlignTo) {
86   struct {
87     uint64_t alignment;
88     uint64_t offset;
89     uint64_t rounded;
90     const void *forgedAddr() const {
91       //  A value of any integral or enumeration type can be converted to a
92       //  pointer type.
93       return reinterpret_cast<const void *>(offset);
94     }
95   } kTests[] = {
96       // MaybeAlign
97       {0, 0, 0},
98       {0, 1, 1},
99       {0, 5, 5},
100       // MaybeAlign / Align
101       {1, 0, 0},
102       {1, 1, 1},
103       {1, 5, 5},
104       {2, 0, 0},
105       {2, 1, 2},
106       {2, 2, 2},
107       {2, 7, 8},
108       {2, 16, 16},
109       {4, 0, 0},
110       {4, 1, 4},
111       {4, 4, 4},
112       {4, 6, 8},
113   };
114   for (const auto &T : kTests) {
115     MaybeAlign A(T.alignment);
116     // Test MaybeAlign
117     EXPECT_EQ(alignTo(T.offset, A), T.rounded);
118     // Test Align
119     if (A) {
120       EXPECT_EQ(alignTo(T.offset, A.getValue()), T.rounded);
121       EXPECT_EQ(alignAddr(T.forgedAddr(), A.getValue()), T.rounded);
122     }
123   }
124 }
125 
126 TEST(AlignmentTest, AlignToWithSkew) {
127   EXPECT_EQ(alignTo(5, Align(8), 0), alignTo(5, Align(8)));
128   EXPECT_EQ(alignTo(5, Align(8), 7), 7U);
129   EXPECT_EQ(alignTo(17, Align(8), 1), 17U);
130   EXPECT_EQ(alignTo(~0LL, Align(8), 3), 3U);
131 }
132 
133 TEST(AlignmentTest, Log2) {
134   for (uint64_t Value : getValidAlignments()) {
135     EXPECT_EQ(Log2(Align(Value)), Log2_64(Value));
136   }
137 }
138 
139 TEST(AlignmentTest, MinAlign) {
140   struct {
141     uint64_t A;
142     uint64_t B;
143     uint64_t MinAlign;
144   } kTests[] = {
145       // MaybeAlign
146       {0, 0, 0},
147       {0, 8, 8},
148       {2, 0, 2},
149       // MaybeAlign / Align
150       {1, 2, 1},
151       {8, 4, 4},
152   };
153   for (const auto &T : kTests) {
154     EXPECT_EQ(commonAlignment(MaybeAlign(T.A), MaybeAlign(T.B)), T.MinAlign);
155     EXPECT_EQ(MinAlign(T.A, T.B), T.MinAlign);
156     if (T.A) {
157       EXPECT_EQ(commonAlignment(Align(T.A), MaybeAlign(T.B)), T.MinAlign);
158     }
159     if (T.B) {
160       EXPECT_EQ(commonAlignment(MaybeAlign(T.A), Align(T.B)), T.MinAlign);
161     }
162     if (T.A && T.B) {
163       EXPECT_EQ(commonAlignment(Align(T.A), Align(T.B)), T.MinAlign);
164     }
165   }
166 }
167 
168 TEST(AlignmentTest, Encode_Decode) {
169   for (uint64_t Value : getValidAlignments()) {
170     {
171       Align Actual(Value);
172       Align Expected = decodeMaybeAlign(encode(Actual)).getValue();
173       EXPECT_EQ(Expected, Actual);
174     }
175     {
176       MaybeAlign Actual(Value);
177       MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
178       EXPECT_EQ(Expected, Actual);
179     }
180   }
181   MaybeAlign Actual(0);
182   MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
183   EXPECT_EQ(Expected, Actual);
184 }
185 
186 TEST(AlignmentTest, isAligned_isAddrAligned) {
187   struct {
188     uint64_t alignment;
189     uint64_t offset;
190     bool isAligned;
191     const void *forgedAddr() const {
192       //  A value of any integral or enumeration type can be converted to a
193       //  pointer type.
194       return reinterpret_cast<const void *>(offset);
195     }
196   } kTests[] = {
197       {1, 0, true},  {1, 1, true},  {1, 5, true},  {2, 0, true},
198       {2, 1, false}, {2, 2, true},  {2, 7, false}, {2, 16, true},
199       {4, 0, true},  {4, 1, false}, {4, 4, true},  {4, 6, false},
200   };
201   for (const auto &T : kTests) {
202     MaybeAlign A(T.alignment);
203     // Test Align
204     if (A) {
205       EXPECT_EQ(isAligned(A.getValue(), T.offset), T.isAligned);
206       EXPECT_EQ(isAddrAligned(A.getValue(), T.forgedAddr()), T.isAligned);
207     }
208   }
209 }
210 
211 TEST(AlignmentTest, offsetToAlignment) {
212   struct {
213     uint64_t alignment;
214     uint64_t offset;
215     uint64_t alignedOffset;
216     const void *forgedAddr() const {
217       //  A value of any integral or enumeration type can be converted to a
218       //  pointer type.
219       return reinterpret_cast<const void *>(offset);
220     }
221   } kTests[] = {
222       {1, 0, 0}, {1, 1, 0},  {1, 5, 0}, {2, 0, 0}, {2, 1, 1}, {2, 2, 0},
223       {2, 7, 1}, {2, 16, 0}, {4, 0, 0}, {4, 1, 3}, {4, 4, 0}, {4, 6, 2},
224   };
225   for (const auto &T : kTests) {
226     const Align A(T.alignment);
227     EXPECT_EQ(offsetToAlignment(T.offset, A), T.alignedOffset);
228     EXPECT_EQ(offsetToAlignedAddr(T.forgedAddr(), A), T.alignedOffset);
229   }
230 }
231 
232 TEST(AlignmentTest, AlignComparisons) {
233   std::vector<uint64_t> ValidAlignments = getValidAlignments();
234   std::sort(ValidAlignments.begin(), ValidAlignments.end());
235   for (size_t I = 1; I < ValidAlignments.size(); ++I) {
236     assert(I >= 1);
237     const Align A(ValidAlignments[I - 1]);
238     const Align B(ValidAlignments[I]);
239     EXPECT_EQ(A, A);
240     EXPECT_NE(A, B);
241     EXPECT_LT(A, B);
242     EXPECT_GT(B, A);
243     EXPECT_LE(A, B);
244     EXPECT_GE(B, A);
245     EXPECT_LE(A, A);
246     EXPECT_GE(A, A);
247 
248     EXPECT_EQ(A, A.value());
249     EXPECT_NE(A, B.value());
250     EXPECT_LT(A, B.value());
251     EXPECT_GT(B, A.value());
252     EXPECT_LE(A, B.value());
253     EXPECT_GE(B, A.value());
254     EXPECT_LE(A, A.value());
255     EXPECT_GE(A, A.value());
256 
257     EXPECT_EQ(std::max(A, B), B);
258     EXPECT_EQ(std::min(A, B), A);
259 
260     const MaybeAlign MA(ValidAlignments[I - 1]);
261     const MaybeAlign MB(ValidAlignments[I]);
262     EXPECT_EQ(MA, MA);
263     EXPECT_NE(MA, MB);
264 
265     EXPECT_EQ(MA, MA ? (*MA).value() : 0);
266     EXPECT_NE(MA, MB ? (*MB).value() : 0);
267 
268     EXPECT_EQ(std::max(A, B), B);
269     EXPECT_EQ(std::min(A, B), A);
270   }
271 }
272 
273 TEST(AlignmentTest, Max) {
274   // We introduce std::max here to test ADL.
275   using std::max;
276 
277   // Uses llvm::max.
278   EXPECT_EQ(max(MaybeAlign(), Align(2)), Align(2));
279   EXPECT_EQ(max(Align(2), MaybeAlign()), Align(2));
280 
281   EXPECT_EQ(max(MaybeAlign(1), Align(2)), Align(2));
282   EXPECT_EQ(max(Align(2), MaybeAlign(1)), Align(2));
283 
284   EXPECT_EQ(max(MaybeAlign(2), Align(2)), Align(2));
285   EXPECT_EQ(max(Align(2), MaybeAlign(2)), Align(2));
286 
287   EXPECT_EQ(max(MaybeAlign(4), Align(2)), Align(4));
288   EXPECT_EQ(max(Align(2), MaybeAlign(4)), Align(4));
289 
290   // Uses std::max.
291   EXPECT_EQ(max(Align(2), Align(4)), Align(4));
292 }
293 
294 TEST(AlignmentTest, AssumeAligned) {
295   EXPECT_EQ(assumeAligned(0), Align(1));
296   EXPECT_EQ(assumeAligned(0), Align());
297   EXPECT_EQ(assumeAligned(1), Align(1));
298   EXPECT_EQ(assumeAligned(1), Align());
299 }
300 
301 // Death tests reply on assert which is disabled in release mode.
302 #ifndef NDEBUG
303 
304 // We use a subset of valid alignments for DEATH_TESTs as they are particularly
305 // slow.
306 std::vector<uint64_t> getValidAlignmentsForDeathTest() {
307   return {1, 1ULL << 31, 1ULL << 63};
308 }
309 
310 std::vector<uint64_t> getNonPowerOfTwo() { return {3, 10, 15}; }
311 
312 TEST(AlignmentDeathTest, CantConvertUnsetMaybe) {
313   EXPECT_DEATH((MaybeAlign(0).getValue()), ".*");
314 }
315 
316 TEST(AlignmentDeathTest, Division) {
317   EXPECT_DEATH(Align(1) / 2, "Can't halve byte alignment");
318 
319   EXPECT_DEATH(Align(8) / 0, "Divisor must be positive and a power of 2");
320   EXPECT_DEATH(Align(8) / 3, "Divisor must be positive and a power of 2");
321 }
322 
323 TEST(AlignmentDeathTest, InvalidCTors) {
324   EXPECT_DEATH((Align(0)), "Value must not be 0");
325   for (uint64_t Value : getNonPowerOfTwo()) {
326     EXPECT_DEATH((Align(Value)), "Alignment is not a power of 2");
327     EXPECT_DEATH((MaybeAlign(Value)),
328                  "Alignment is neither 0 nor a power of 2");
329   }
330 }
331 
332 TEST(AlignmentDeathTest, ComparisonsWithZero) {
333   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
334     EXPECT_DEATH((void)(Align(Value) == 0), ".* should be defined");
335     EXPECT_DEATH((void)(Align(Value) != 0), ".* should be defined");
336     EXPECT_DEATH((void)(Align(Value) >= 0), ".* should be defined");
337     EXPECT_DEATH((void)(Align(Value) <= 0), ".* should be defined");
338     EXPECT_DEATH((void)(Align(Value) > 0), ".* should be defined");
339     EXPECT_DEATH((void)(Align(Value) < 0), ".* should be defined");
340   }
341 }
342 
343 TEST(AlignmentDeathTest, CompareMaybeAlignToZero) {
344   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
345     // MaybeAlign is allowed to be == or != 0
346     (void)(MaybeAlign(Value) == 0);
347     (void)(MaybeAlign(Value) != 0);
348   }
349 }
350 
351 TEST(AlignmentDeathTest, AlignAddr) {
352   const void *const unaligned_high_ptr =
353       reinterpret_cast<const void *>(std::numeric_limits<uintptr_t>::max() - 1);
354   EXPECT_DEATH(alignAddr(unaligned_high_ptr, Align(16)), "Overflow");
355 }
356 
357 #endif // NDEBUG
358 
359 } // end anonymous namespace
360 
361 #ifdef _MSC_VER
362 #pragma warning(pop)
363 #endif
364