xref: /llvm-project/llvm/unittests/Support/AlignmentTest.cpp (revision d1f23bd2250b3f1f84ed3c210a6cdcc0065761f1)
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 std::vector<uint64_t> getValidAlignments() {
25   std::vector<uint64_t> Out;
26   for (size_t Shift = 0; Shift < 64; ++Shift)
27     Out.push_back(1ULL << Shift);
28   return Out;
29 }
30 
31 TEST(AlignmentTest, AlignDefaultCTor) {
32   EXPECT_EQ(Align().value(), 1ULL);
33   EXPECT_EQ(Align::None().value(), 1ULL);
34 }
35 
36 TEST(AlignmentTest, MaybeAlignDefaultCTor) {
37   EXPECT_FALSE(MaybeAlign().hasValue());
38 }
39 
40 TEST(AlignmentTest, ValidCTors) {
41   for (uint64_t Value : getValidAlignments()) {
42     EXPECT_EQ(Align(Value).value(), Value);
43     EXPECT_EQ((*MaybeAlign(Value)).value(), Value);
44   }
45 }
46 
47 TEST(AlignmentTest, CheckMaybeAlignHasValue) {
48   EXPECT_TRUE(MaybeAlign(1));
49   EXPECT_TRUE(MaybeAlign(1).hasValue());
50   EXPECT_FALSE(MaybeAlign(0));
51   EXPECT_FALSE(MaybeAlign(0).hasValue());
52   EXPECT_FALSE(MaybeAlign());
53   EXPECT_FALSE(MaybeAlign().hasValue());
54 }
55 
56 TEST(AlignmentTest, Division) {
57   for (uint64_t Value : getValidAlignments()) {
58     if (Value > 1) {
59       EXPECT_EQ(Align(Value) / 2, Value / 2);
60       EXPECT_EQ(MaybeAlign(Value) / 2, Value / 2);
61     }
62   }
63   EXPECT_EQ(MaybeAlign(0) / 2, MaybeAlign(0));
64 }
65 
66 TEST(AlignmentTest, AlignTo) {
67   struct {
68     uint64_t alignment;
69     uint64_t offset;
70     uint64_t rounded;
71   } kTests[] = {
72       // MaybeAlign
73       {0, 0, 0},
74       {0, 1, 1},
75       {0, 5, 5},
76       // MaybeAlign / Align
77       {1, 0, 0},
78       {1, 1, 1},
79       {1, 5, 5},
80       {2, 0, 0},
81       {2, 1, 2},
82       {2, 2, 2},
83       {2, 7, 8},
84       {2, 16, 16},
85       {4, 0, 0},
86       {4, 1, 4},
87       {4, 4, 4},
88       {4, 6, 8},
89   };
90   for (const auto &T : kTests) {
91     MaybeAlign A(T.alignment);
92     // Test MaybeAlign
93     EXPECT_EQ(alignTo(T.offset, A), T.rounded);
94     // Test Align
95     if (A) {
96       EXPECT_EQ(alignTo(T.offset, A.getValue()), T.rounded);
97     }
98   }
99 }
100 
101 TEST(AlignmentTest, Log2) {
102   for (uint64_t Value : getValidAlignments()) {
103     EXPECT_EQ(Log2(Align(Value)), Log2_64(Value));
104     EXPECT_EQ(Log2(MaybeAlign(Value)), Log2_64(Value));
105   }
106 }
107 
108 TEST(AlignmentTest, MinAlign) {
109   struct {
110     uint64_t A;
111     uint64_t B;
112     uint64_t MinAlign;
113   } kTests[] = {
114       // MaybeAlign
115       {0, 0, 0},
116       {0, 8, 8},
117       {2, 0, 2},
118       // MaybeAlign / Align
119       {1, 2, 1},
120       {8, 4, 4},
121   };
122   for (const auto &T : kTests) {
123     EXPECT_EQ(commonAlignment(MaybeAlign(T.A), MaybeAlign(T.B)), T.MinAlign);
124     EXPECT_EQ(MinAlign(T.A, T.B), T.MinAlign);
125     if (T.A) {
126       EXPECT_EQ(commonAlignment(Align(T.A), MaybeAlign(T.B)), T.MinAlign);
127     }
128     if (T.B) {
129       EXPECT_EQ(commonAlignment(MaybeAlign(T.A), Align(T.B)), T.MinAlign);
130     }
131     if (T.A && T.B) {
132       EXPECT_EQ(commonAlignment(Align(T.A), Align(T.B)), T.MinAlign);
133     }
134   }
135 }
136 
137 TEST(AlignmentTest, Encode_Decode) {
138   for (uint64_t Value : getValidAlignments()) {
139     {
140       Align Actual(Value);
141       Align Expected = decodeMaybeAlign(encode(Actual)).getValue();
142       EXPECT_EQ(Expected, Actual);
143     }
144     {
145       MaybeAlign Actual(Value);
146       MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
147       EXPECT_EQ(Expected, Actual);
148     }
149   }
150   MaybeAlign Actual(0);
151   MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
152   EXPECT_EQ(Expected, Actual);
153 }
154 
155 TEST(AlignmentTest, isAligned) {
156   struct {
157     uint64_t alignment;
158     uint64_t offset;
159     bool isAligned;
160   } kTests[] = {
161       // MaybeAlign / Align
162       {1, 0, true},  {1, 1, true},  {1, 5, true},  {2, 0, true},
163       {2, 1, false}, {2, 2, true},  {2, 7, false}, {2, 16, true},
164       {4, 0, true},  {4, 1, false}, {4, 4, true},  {4, 6, false},
165   };
166   for (const auto &T : kTests) {
167     MaybeAlign A(T.alignment);
168     // Test MaybeAlign
169     EXPECT_EQ(isAligned(A, T.offset), T.isAligned);
170     // Test Align
171     if (A) {
172       EXPECT_EQ(isAligned(A.getValue(), T.offset), T.isAligned);
173     }
174   }
175 }
176 
177 TEST(AlignmentTest, AlignComparisons) {
178   std::vector<uint64_t> ValidAlignments = getValidAlignments();
179   std::sort(ValidAlignments.begin(), ValidAlignments.end());
180   for (size_t I = 1; I < ValidAlignments.size(); ++I) {
181     assert(I >= 1);
182     const Align A(ValidAlignments[I - 1]);
183     const Align B(ValidAlignments[I]);
184     EXPECT_EQ(A, A);
185     EXPECT_NE(A, B);
186     EXPECT_LT(A, B);
187     EXPECT_GT(B, A);
188     EXPECT_LE(A, B);
189     EXPECT_GE(B, A);
190     EXPECT_LE(A, A);
191     EXPECT_GE(A, A);
192 
193     EXPECT_EQ(A, A.value());
194     EXPECT_NE(A, B.value());
195     EXPECT_LT(A, B.value());
196     EXPECT_GT(B, A.value());
197     EXPECT_LE(A, B.value());
198     EXPECT_GE(B, A.value());
199     EXPECT_LE(A, A.value());
200     EXPECT_GE(A, A.value());
201 
202     EXPECT_EQ(std::max(A, B), B);
203     EXPECT_EQ(std::min(A, B), A);
204 
205     const MaybeAlign MA(ValidAlignments[I - 1]);
206     const MaybeAlign MB(ValidAlignments[I]);
207     EXPECT_EQ(MA, MA);
208     EXPECT_NE(MA, MB);
209     EXPECT_LT(MA, MB);
210     EXPECT_GT(MB, MA);
211     EXPECT_LE(MA, MB);
212     EXPECT_GE(MB, MA);
213     EXPECT_LE(MA, MA);
214     EXPECT_GE(MA, MA);
215 
216     EXPECT_EQ(MA, MA ? (*MA).value() : 0);
217     EXPECT_NE(MA, MB ? (*MB).value() : 0);
218     EXPECT_LT(MA, MB ? (*MB).value() : 0);
219     EXPECT_GT(MB, MA ? (*MA).value() : 0);
220     EXPECT_LE(MA, MB ? (*MB).value() : 0);
221     EXPECT_GE(MB, MA ? (*MA).value() : 0);
222     EXPECT_LE(MA, MA ? (*MA).value() : 0);
223     EXPECT_GE(MA, MA ? (*MA).value() : 0);
224 
225     EXPECT_EQ(std::max(A, B), B);
226     EXPECT_EQ(std::min(A, B), A);
227   }
228 }
229 
230 TEST(AlignmentTest, Max) {
231   // We introduce std::max here to test ADL.
232   using std::max;
233 
234   // Uses llvm::max.
235   EXPECT_EQ(max(MaybeAlign(), Align(2)), Align(2));
236   EXPECT_EQ(max(Align(2), MaybeAlign()), Align(2));
237 
238   EXPECT_EQ(max(MaybeAlign(1), Align(2)), Align(2));
239   EXPECT_EQ(max(Align(2), MaybeAlign(1)), Align(2));
240 
241   EXPECT_EQ(max(MaybeAlign(2), Align(2)), Align(2));
242   EXPECT_EQ(max(Align(2), MaybeAlign(2)), Align(2));
243 
244   EXPECT_EQ(max(MaybeAlign(4), Align(2)), Align(4));
245   EXPECT_EQ(max(Align(2), MaybeAlign(4)), Align(4));
246 
247   // Uses std::max.
248   EXPECT_EQ(max(Align(2), Align(4)), Align(4));
249   EXPECT_EQ(max(MaybeAlign(2), MaybeAlign(4)), MaybeAlign(4));
250   EXPECT_EQ(max(MaybeAlign(), MaybeAlign()), MaybeAlign());
251 }
252 
253 TEST(AlignmentTest, AssumeAligned) {
254   EXPECT_EQ(assumeAligned(0), Align(1));
255   EXPECT_EQ(assumeAligned(0), Align());
256   EXPECT_EQ(assumeAligned(1), Align(1));
257   EXPECT_EQ(assumeAligned(1), Align());
258 }
259 
260 // Death tests reply on assert which is disabled in release mode.
261 #ifndef NDEBUG
262 
263 // We use a subset of valid alignments for DEATH_TESTs as they are particularly
264 // slow.
265 std::vector<uint64_t> getValidAlignmentsForDeathTest() {
266   return {1, 1ULL << 31, 1ULL << 63};
267 }
268 
269 std::vector<uint64_t> getNonPowerOfTwo() { return {3, 10, 15}; }
270 
271 TEST(AlignmentDeathTest, Log2) {
272   EXPECT_DEATH(Log2(MaybeAlign(0)), ".* should be defined");
273 }
274 
275 TEST(AlignmentDeathTest, CantConvertUnsetMaybe) {
276   EXPECT_DEATH((MaybeAlign(0).getValue()), ".*");
277 }
278 
279 TEST(AlignmentDeathTest, Division) {
280   EXPECT_DEATH(Align(1) / 2, "Can't halve byte alignment");
281   EXPECT_DEATH(MaybeAlign(1) / 2, "Can't halve byte alignment");
282 
283   EXPECT_DEATH(Align(8) / 0, "Divisor must be positive and a power of 2");
284   EXPECT_DEATH(Align(8) / 3, "Divisor must be positive and a power of 2");
285 }
286 
287 TEST(AlignmentDeathTest, InvalidCTors) {
288   EXPECT_DEATH((Align(0)), "Value must not be 0");
289   for (uint64_t Value : getNonPowerOfTwo()) {
290     EXPECT_DEATH((Align(Value)), "Alignment is not a power of 2");
291     EXPECT_DEATH((MaybeAlign(Value)),
292                  "Alignment is neither 0 nor a power of 2");
293   }
294 }
295 
296 TEST(AlignmentDeathTest, ComparisonsWithZero) {
297   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
298     EXPECT_DEATH((void)(Align(Value) == 0), ".* should be defined");
299     EXPECT_DEATH((void)(Align(Value) != 0), ".* should be defined");
300     EXPECT_DEATH((void)(Align(Value) >= 0), ".* should be defined");
301     EXPECT_DEATH((void)(Align(Value) <= 0), ".* should be defined");
302     EXPECT_DEATH((void)(Align(Value) > 0), ".* should be defined");
303     EXPECT_DEATH((void)(Align(Value) < 0), ".* should be defined");
304   }
305 }
306 
307 TEST(AlignmentDeathTest, CompareMaybeAlignToZero) {
308   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
309     // MaybeAlign is allowed to be == or != 0
310     (void)(MaybeAlign(Value) == 0);
311     (void)(MaybeAlign(Value) != 0);
312     EXPECT_DEATH((void)(MaybeAlign(Value) >= 0), ".* should be defined");
313     EXPECT_DEATH((void)(MaybeAlign(Value) <= 0), ".* should be defined");
314     EXPECT_DEATH((void)(MaybeAlign(Value) > 0), ".* should be defined");
315     EXPECT_DEATH((void)(MaybeAlign(Value) < 0), ".* should be defined");
316   }
317 }
318 
319 TEST(AlignmentDeathTest, CompareAlignToUndefMaybeAlign) {
320   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
321     EXPECT_DEATH((void)(Align(Value) == MaybeAlign(0)), ".* should be defined");
322     EXPECT_DEATH((void)(Align(Value) != MaybeAlign(0)), ".* should be defined");
323     EXPECT_DEATH((void)(Align(Value) >= MaybeAlign(0)), ".* should be defined");
324     EXPECT_DEATH((void)(Align(Value) <= MaybeAlign(0)), ".* should be defined");
325     EXPECT_DEATH((void)(Align(Value) > MaybeAlign(0)), ".* should be defined");
326     EXPECT_DEATH((void)(Align(Value) < MaybeAlign(0)), ".* should be defined");
327   }
328 }
329 
330 #endif // NDEBUG
331 
332 } // end anonymous namespace
333 
334 #ifdef _MSC_VER
335 #pragma warning(pop)
336 #endif
337