xref: /llvm-project/llvm/unittests/Support/AlignmentTest.cpp (revision 415df89e22abe3defa06cbc901a173e5a6791f8d)
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(8), 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   EXPECT_EQ(Align::None().value(), 1ULL);
56 }
57 
58 TEST(AlignmentTest, MaybeAlignDefaultCTor) {
59   EXPECT_FALSE(MaybeAlign().hasValue());
60 }
61 
62 TEST(AlignmentTest, ValidCTors) {
63   for (uint64_t Value : getValidAlignments()) {
64     EXPECT_EQ(Align(Value).value(), Value);
65     EXPECT_EQ((*MaybeAlign(Value)).value(), Value);
66   }
67 }
68 
69 TEST(AlignmentTest, CheckMaybeAlignHasValue) {
70   EXPECT_TRUE(MaybeAlign(1));
71   EXPECT_TRUE(MaybeAlign(1).hasValue());
72   EXPECT_FALSE(MaybeAlign(0));
73   EXPECT_FALSE(MaybeAlign(0).hasValue());
74   EXPECT_FALSE(MaybeAlign());
75   EXPECT_FALSE(MaybeAlign().hasValue());
76 }
77 
78 TEST(AlignmentTest, Division) {
79   for (uint64_t Value : getValidAlignments()) {
80     if (Value > 1) {
81       EXPECT_EQ(Align(Value) / 2, Value / 2);
82       EXPECT_EQ(MaybeAlign(Value) / 2, Value / 2);
83     }
84   }
85   EXPECT_EQ(MaybeAlign(0) / 2, MaybeAlign(0));
86 }
87 
88 TEST(AlignmentTest, AlignTo) {
89   struct {
90     uint64_t alignment;
91     uint64_t offset;
92     uint64_t rounded;
93   } kTests[] = {
94       // MaybeAlign
95       {0, 0, 0},
96       {0, 1, 1},
97       {0, 5, 5},
98       // MaybeAlign / Align
99       {1, 0, 0},
100       {1, 1, 1},
101       {1, 5, 5},
102       {2, 0, 0},
103       {2, 1, 2},
104       {2, 2, 2},
105       {2, 7, 8},
106       {2, 16, 16},
107       {4, 0, 0},
108       {4, 1, 4},
109       {4, 4, 4},
110       {4, 6, 8},
111   };
112   for (const auto &T : kTests) {
113     MaybeAlign A(T.alignment);
114     // Test MaybeAlign
115     EXPECT_EQ(alignTo(T.offset, A), T.rounded);
116     // Test Align
117     if (A) {
118       EXPECT_EQ(alignTo(T.offset, A.getValue()), T.rounded);
119     }
120   }
121 }
122 
123 TEST(AlignmentTest, Log2) {
124   for (uint64_t Value : getValidAlignments()) {
125     EXPECT_EQ(Log2(Align(Value)), Log2_64(Value));
126     EXPECT_EQ(Log2(MaybeAlign(Value)), Log2_64(Value));
127   }
128 }
129 
130 TEST(AlignmentTest, MinAlign) {
131   struct {
132     uint64_t A;
133     uint64_t B;
134     uint64_t MinAlign;
135   } kTests[] = {
136       // MaybeAlign
137       {0, 0, 0},
138       {0, 8, 8},
139       {2, 0, 2},
140       // MaybeAlign / Align
141       {1, 2, 1},
142       {8, 4, 4},
143   };
144   for (const auto &T : kTests) {
145     EXPECT_EQ(commonAlignment(MaybeAlign(T.A), MaybeAlign(T.B)), T.MinAlign);
146     EXPECT_EQ(MinAlign(T.A, T.B), T.MinAlign);
147     if (T.A) {
148       EXPECT_EQ(commonAlignment(Align(T.A), MaybeAlign(T.B)), T.MinAlign);
149     }
150     if (T.B) {
151       EXPECT_EQ(commonAlignment(MaybeAlign(T.A), Align(T.B)), T.MinAlign);
152     }
153     if (T.A && T.B) {
154       EXPECT_EQ(commonAlignment(Align(T.A), Align(T.B)), T.MinAlign);
155     }
156   }
157 }
158 
159 TEST(AlignmentTest, Encode_Decode) {
160   for (uint64_t Value : getValidAlignments()) {
161     {
162       Align Actual(Value);
163       Align Expected = decodeMaybeAlign(encode(Actual)).getValue();
164       EXPECT_EQ(Expected, Actual);
165     }
166     {
167       MaybeAlign Actual(Value);
168       MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
169       EXPECT_EQ(Expected, Actual);
170     }
171   }
172   MaybeAlign Actual(0);
173   MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
174   EXPECT_EQ(Expected, Actual);
175 }
176 
177 TEST(AlignmentTest, isAligned) {
178   struct {
179     uint64_t alignment;
180     uint64_t offset;
181     bool isAligned;
182   } kTests[] = {
183       // MaybeAlign / Align
184       {1, 0, true},  {1, 1, true},  {1, 5, true},  {2, 0, true},
185       {2, 1, false}, {2, 2, true},  {2, 7, false}, {2, 16, true},
186       {4, 0, true},  {4, 1, false}, {4, 4, true},  {4, 6, false},
187   };
188   for (const auto &T : kTests) {
189     MaybeAlign A(T.alignment);
190     // Test MaybeAlign
191     EXPECT_EQ(isAligned(A, T.offset), T.isAligned);
192     // Test Align
193     if (A) {
194       EXPECT_EQ(isAligned(A.getValue(), T.offset), T.isAligned);
195     }
196   }
197 }
198 
199 TEST(AlignmentTest, AlignComparisons) {
200   std::vector<uint64_t> ValidAlignments = getValidAlignments();
201   std::sort(ValidAlignments.begin(), ValidAlignments.end());
202   for (size_t I = 1; I < ValidAlignments.size(); ++I) {
203     assert(I >= 1);
204     const Align A(ValidAlignments[I - 1]);
205     const Align B(ValidAlignments[I]);
206     EXPECT_EQ(A, A);
207     EXPECT_NE(A, B);
208     EXPECT_LT(A, B);
209     EXPECT_GT(B, A);
210     EXPECT_LE(A, B);
211     EXPECT_GE(B, A);
212     EXPECT_LE(A, A);
213     EXPECT_GE(A, A);
214 
215     EXPECT_EQ(A, A.value());
216     EXPECT_NE(A, B.value());
217     EXPECT_LT(A, B.value());
218     EXPECT_GT(B, A.value());
219     EXPECT_LE(A, B.value());
220     EXPECT_GE(B, A.value());
221     EXPECT_LE(A, A.value());
222     EXPECT_GE(A, A.value());
223 
224     EXPECT_EQ(std::max(A, B), B);
225     EXPECT_EQ(std::min(A, B), A);
226 
227     const MaybeAlign MA(ValidAlignments[I - 1]);
228     const MaybeAlign MB(ValidAlignments[I]);
229     EXPECT_EQ(MA, MA);
230     EXPECT_NE(MA, MB);
231     EXPECT_LT(MA, MB);
232     EXPECT_GT(MB, MA);
233     EXPECT_LE(MA, MB);
234     EXPECT_GE(MB, MA);
235     EXPECT_LE(MA, MA);
236     EXPECT_GE(MA, MA);
237 
238     EXPECT_EQ(MA, MA ? (*MA).value() : 0);
239     EXPECT_NE(MA, MB ? (*MB).value() : 0);
240     EXPECT_LT(MA, MB ? (*MB).value() : 0);
241     EXPECT_GT(MB, MA ? (*MA).value() : 0);
242     EXPECT_LE(MA, MB ? (*MB).value() : 0);
243     EXPECT_GE(MB, MA ? (*MA).value() : 0);
244     EXPECT_LE(MA, MA ? (*MA).value() : 0);
245     EXPECT_GE(MA, MA ? (*MA).value() : 0);
246 
247     EXPECT_EQ(std::max(A, B), B);
248     EXPECT_EQ(std::min(A, B), A);
249   }
250 }
251 
252 TEST(AlignmentTest, Max) {
253   // We introduce std::max here to test ADL.
254   using std::max;
255 
256   // Uses llvm::max.
257   EXPECT_EQ(max(MaybeAlign(), Align(2)), Align(2));
258   EXPECT_EQ(max(Align(2), MaybeAlign()), Align(2));
259 
260   EXPECT_EQ(max(MaybeAlign(1), Align(2)), Align(2));
261   EXPECT_EQ(max(Align(2), MaybeAlign(1)), Align(2));
262 
263   EXPECT_EQ(max(MaybeAlign(2), Align(2)), Align(2));
264   EXPECT_EQ(max(Align(2), MaybeAlign(2)), Align(2));
265 
266   EXPECT_EQ(max(MaybeAlign(4), Align(2)), Align(4));
267   EXPECT_EQ(max(Align(2), MaybeAlign(4)), Align(4));
268 
269   // Uses std::max.
270   EXPECT_EQ(max(Align(2), Align(4)), Align(4));
271   EXPECT_EQ(max(MaybeAlign(2), MaybeAlign(4)), MaybeAlign(4));
272   EXPECT_EQ(max(MaybeAlign(), MaybeAlign()), MaybeAlign());
273 }
274 
275 TEST(AlignmentTest, AssumeAligned) {
276   EXPECT_EQ(assumeAligned(0), Align(1));
277   EXPECT_EQ(assumeAligned(0), Align());
278   EXPECT_EQ(assumeAligned(1), Align(1));
279   EXPECT_EQ(assumeAligned(1), Align());
280 }
281 
282 // Death tests reply on assert which is disabled in release mode.
283 #ifndef NDEBUG
284 
285 // We use a subset of valid alignments for DEATH_TESTs as they are particularly
286 // slow.
287 std::vector<uint64_t> getValidAlignmentsForDeathTest() {
288   return {1, 1ULL << 31, 1ULL << 63};
289 }
290 
291 std::vector<uint64_t> getNonPowerOfTwo() { return {3, 10, 15}; }
292 
293 TEST(AlignmentDeathTest, Log2) {
294   EXPECT_DEATH(Log2(MaybeAlign(0)), ".* should be defined");
295 }
296 
297 TEST(AlignmentDeathTest, CantConvertUnsetMaybe) {
298   EXPECT_DEATH((MaybeAlign(0).getValue()), ".*");
299 }
300 
301 TEST(AlignmentDeathTest, Division) {
302   EXPECT_DEATH(Align(1) / 2, "Can't halve byte alignment");
303   EXPECT_DEATH(MaybeAlign(1) / 2, "Can't halve byte alignment");
304 
305   EXPECT_DEATH(Align(8) / 0, "Divisor must be positive and a power of 2");
306   EXPECT_DEATH(Align(8) / 3, "Divisor must be positive and a power of 2");
307 }
308 
309 TEST(AlignmentDeathTest, InvalidCTors) {
310   EXPECT_DEATH((Align(0)), "Value must not be 0");
311   for (uint64_t Value : getNonPowerOfTwo()) {
312     EXPECT_DEATH((Align(Value)), "Alignment is not a power of 2");
313     EXPECT_DEATH((MaybeAlign(Value)),
314                  "Alignment is neither 0 nor a power of 2");
315   }
316 }
317 
318 TEST(AlignmentDeathTest, ComparisonsWithZero) {
319   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
320     EXPECT_DEATH((void)(Align(Value) == 0), ".* should be defined");
321     EXPECT_DEATH((void)(Align(Value) != 0), ".* should be defined");
322     EXPECT_DEATH((void)(Align(Value) >= 0), ".* should be defined");
323     EXPECT_DEATH((void)(Align(Value) <= 0), ".* should be defined");
324     EXPECT_DEATH((void)(Align(Value) > 0), ".* should be defined");
325     EXPECT_DEATH((void)(Align(Value) < 0), ".* should be defined");
326   }
327 }
328 
329 TEST(AlignmentDeathTest, CompareMaybeAlignToZero) {
330   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
331     // MaybeAlign is allowed to be == or != 0
332     (void)(MaybeAlign(Value) == 0);
333     (void)(MaybeAlign(Value) != 0);
334     EXPECT_DEATH((void)(MaybeAlign(Value) >= 0), ".* should be defined");
335     EXPECT_DEATH((void)(MaybeAlign(Value) <= 0), ".* should be defined");
336     EXPECT_DEATH((void)(MaybeAlign(Value) > 0), ".* should be defined");
337     EXPECT_DEATH((void)(MaybeAlign(Value) < 0), ".* should be defined");
338   }
339 }
340 
341 TEST(AlignmentDeathTest, CompareAlignToUndefMaybeAlign) {
342   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
343     EXPECT_DEATH((void)(Align(Value) == MaybeAlign(0)), ".* should be defined");
344     EXPECT_DEATH((void)(Align(Value) != MaybeAlign(0)), ".* should be defined");
345     EXPECT_DEATH((void)(Align(Value) >= MaybeAlign(0)), ".* should be defined");
346     EXPECT_DEATH((void)(Align(Value) <= MaybeAlign(0)), ".* should be defined");
347     EXPECT_DEATH((void)(Align(Value) > MaybeAlign(0)), ".* should be defined");
348     EXPECT_DEATH((void)(Align(Value) < MaybeAlign(0)), ".* should be defined");
349   }
350 }
351 
352 #endif // NDEBUG
353 
354 } // end anonymous namespace
355 
356 #ifdef _MSC_VER
357 #pragma warning(pop)
358 #endif
359