xref: /llvm-project/llvm/unittests/Support/AlignmentTest.cpp (revision b3af236fb5fc6e50fcc1b54d868f0bff557f3fb1)
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, CompileTimeConstant) {
48   EXPECT_EQ(Align::Constant<1>(), Align(1));
49   EXPECT_EQ(Align::Constant<2>(), Align(2));
50   EXPECT_EQ(Align::Constant<4>(), Align(4));
51   EXPECT_EQ(Align::Constant<8>(), Align(8));
52   EXPECT_EQ(Align::Constant<16>(), Align(16));
53   EXPECT_EQ(Align::Constant<32>(), Align(32));
54   EXPECT_EQ(Align::Constant<64>(), Align(64));
55 }
56 
57 TEST(AlignmentTest, CheckMaybeAlignHasValue) {
58   EXPECT_TRUE(MaybeAlign(1));
59   EXPECT_TRUE(MaybeAlign(1).hasValue());
60   EXPECT_FALSE(MaybeAlign(0));
61   EXPECT_FALSE(MaybeAlign(0).hasValue());
62   EXPECT_FALSE(MaybeAlign());
63   EXPECT_FALSE(MaybeAlign().hasValue());
64 }
65 
66 TEST(AlignmentTest, Division) {
67   for (uint64_t Value : getValidAlignments()) {
68     if (Value > 1) {
69       EXPECT_EQ(Align(Value) / 2, Value / 2);
70       EXPECT_EQ(MaybeAlign(Value) / 2, Value / 2);
71     }
72   }
73   EXPECT_EQ(MaybeAlign(0) / 2, MaybeAlign(0));
74 }
75 
76 TEST(AlignmentTest, AlignTo) {
77   struct {
78     uint64_t alignment;
79     uint64_t offset;
80     uint64_t rounded;
81   } kTests[] = {
82       // MaybeAlign
83       {0, 0, 0},
84       {0, 1, 1},
85       {0, 5, 5},
86       // MaybeAlign / Align
87       {1, 0, 0},
88       {1, 1, 1},
89       {1, 5, 5},
90       {2, 0, 0},
91       {2, 1, 2},
92       {2, 2, 2},
93       {2, 7, 8},
94       {2, 16, 16},
95       {4, 0, 0},
96       {4, 1, 4},
97       {4, 4, 4},
98       {4, 6, 8},
99   };
100   for (const auto &T : kTests) {
101     MaybeAlign A(T.alignment);
102     // Test MaybeAlign
103     EXPECT_EQ(alignTo(T.offset, A), T.rounded);
104     // Test Align
105     if (A) {
106       EXPECT_EQ(alignTo(T.offset, A.getValue()), T.rounded);
107     }
108   }
109 }
110 
111 TEST(AlignmentTest, Log2) {
112   for (uint64_t Value : getValidAlignments()) {
113     EXPECT_EQ(Log2(Align(Value)), Log2_64(Value));
114     EXPECT_EQ(Log2(MaybeAlign(Value)), Log2_64(Value));
115   }
116 }
117 
118 TEST(AlignmentTest, MinAlign) {
119   struct {
120     uint64_t A;
121     uint64_t B;
122     uint64_t MinAlign;
123   } kTests[] = {
124       // MaybeAlign
125       {0, 0, 0},
126       {0, 8, 8},
127       {2, 0, 2},
128       // MaybeAlign / Align
129       {1, 2, 1},
130       {8, 4, 4},
131   };
132   for (const auto &T : kTests) {
133     EXPECT_EQ(commonAlignment(MaybeAlign(T.A), MaybeAlign(T.B)), T.MinAlign);
134     EXPECT_EQ(MinAlign(T.A, T.B), T.MinAlign);
135     if (T.A) {
136       EXPECT_EQ(commonAlignment(Align(T.A), MaybeAlign(T.B)), T.MinAlign);
137     }
138     if (T.B) {
139       EXPECT_EQ(commonAlignment(MaybeAlign(T.A), Align(T.B)), T.MinAlign);
140     }
141     if (T.A && T.B) {
142       EXPECT_EQ(commonAlignment(Align(T.A), Align(T.B)), T.MinAlign);
143     }
144   }
145 }
146 
147 TEST(AlignmentTest, Encode_Decode) {
148   for (uint64_t Value : getValidAlignments()) {
149     {
150       Align Actual(Value);
151       Align Expected = decodeMaybeAlign(encode(Actual)).getValue();
152       EXPECT_EQ(Expected, Actual);
153     }
154     {
155       MaybeAlign Actual(Value);
156       MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
157       EXPECT_EQ(Expected, Actual);
158     }
159   }
160   MaybeAlign Actual(0);
161   MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
162   EXPECT_EQ(Expected, Actual);
163 }
164 
165 TEST(AlignmentTest, isAligned) {
166   struct {
167     uint64_t alignment;
168     uint64_t offset;
169     bool isAligned;
170   } kTests[] = {
171       // MaybeAlign / Align
172       {1, 0, true},  {1, 1, true},  {1, 5, true},  {2, 0, true},
173       {2, 1, false}, {2, 2, true},  {2, 7, false}, {2, 16, true},
174       {4, 0, true},  {4, 1, false}, {4, 4, true},  {4, 6, false},
175   };
176   for (const auto &T : kTests) {
177     MaybeAlign A(T.alignment);
178     // Test MaybeAlign
179     EXPECT_EQ(isAligned(A, T.offset), T.isAligned);
180     // Test Align
181     if (A) {
182       EXPECT_EQ(isAligned(A.getValue(), T.offset), T.isAligned);
183     }
184   }
185 }
186 
187 TEST(AlignmentTest, AlignComparisons) {
188   std::vector<uint64_t> ValidAlignments = getValidAlignments();
189   std::sort(ValidAlignments.begin(), ValidAlignments.end());
190   for (size_t I = 1; I < ValidAlignments.size(); ++I) {
191     assert(I >= 1);
192     const Align A(ValidAlignments[I - 1]);
193     const Align B(ValidAlignments[I]);
194     EXPECT_EQ(A, A);
195     EXPECT_NE(A, B);
196     EXPECT_LT(A, B);
197     EXPECT_GT(B, A);
198     EXPECT_LE(A, B);
199     EXPECT_GE(B, A);
200     EXPECT_LE(A, A);
201     EXPECT_GE(A, A);
202 
203     EXPECT_EQ(A, A.value());
204     EXPECT_NE(A, B.value());
205     EXPECT_LT(A, B.value());
206     EXPECT_GT(B, A.value());
207     EXPECT_LE(A, B.value());
208     EXPECT_GE(B, A.value());
209     EXPECT_LE(A, A.value());
210     EXPECT_GE(A, A.value());
211 
212     EXPECT_EQ(std::max(A, B), B);
213     EXPECT_EQ(std::min(A, B), A);
214 
215     const MaybeAlign MA(ValidAlignments[I - 1]);
216     const MaybeAlign MB(ValidAlignments[I]);
217     EXPECT_EQ(MA, MA);
218     EXPECT_NE(MA, MB);
219     EXPECT_LT(MA, MB);
220     EXPECT_GT(MB, MA);
221     EXPECT_LE(MA, MB);
222     EXPECT_GE(MB, MA);
223     EXPECT_LE(MA, MA);
224     EXPECT_GE(MA, MA);
225 
226     EXPECT_EQ(MA, MA ? (*MA).value() : 0);
227     EXPECT_NE(MA, MB ? (*MB).value() : 0);
228     EXPECT_LT(MA, MB ? (*MB).value() : 0);
229     EXPECT_GT(MB, MA ? (*MA).value() : 0);
230     EXPECT_LE(MA, MB ? (*MB).value() : 0);
231     EXPECT_GE(MB, MA ? (*MA).value() : 0);
232     EXPECT_LE(MA, MA ? (*MA).value() : 0);
233     EXPECT_GE(MA, MA ? (*MA).value() : 0);
234 
235     EXPECT_EQ(std::max(A, B), B);
236     EXPECT_EQ(std::min(A, B), A);
237   }
238 }
239 
240 TEST(AlignmentTest, Max) {
241   // We introduce std::max here to test ADL.
242   using std::max;
243 
244   // Uses llvm::max.
245   EXPECT_EQ(max(MaybeAlign(), Align(2)), Align(2));
246   EXPECT_EQ(max(Align(2), MaybeAlign()), Align(2));
247 
248   EXPECT_EQ(max(MaybeAlign(1), Align(2)), Align(2));
249   EXPECT_EQ(max(Align(2), MaybeAlign(1)), Align(2));
250 
251   EXPECT_EQ(max(MaybeAlign(2), Align(2)), Align(2));
252   EXPECT_EQ(max(Align(2), MaybeAlign(2)), Align(2));
253 
254   EXPECT_EQ(max(MaybeAlign(4), Align(2)), Align(4));
255   EXPECT_EQ(max(Align(2), MaybeAlign(4)), Align(4));
256 
257   // Uses std::max.
258   EXPECT_EQ(max(Align(2), Align(4)), Align(4));
259   EXPECT_EQ(max(MaybeAlign(2), MaybeAlign(4)), MaybeAlign(4));
260   EXPECT_EQ(max(MaybeAlign(), MaybeAlign()), MaybeAlign());
261 }
262 
263 TEST(AlignmentTest, AssumeAligned) {
264   EXPECT_EQ(assumeAligned(0), Align(1));
265   EXPECT_EQ(assumeAligned(0), Align());
266   EXPECT_EQ(assumeAligned(1), Align(1));
267   EXPECT_EQ(assumeAligned(1), Align());
268 }
269 
270 // Death tests reply on assert which is disabled in release mode.
271 #ifndef NDEBUG
272 
273 // We use a subset of valid alignments for DEATH_TESTs as they are particularly
274 // slow.
275 std::vector<uint64_t> getValidAlignmentsForDeathTest() {
276   return {1, 1ULL << 31, 1ULL << 63};
277 }
278 
279 std::vector<uint64_t> getNonPowerOfTwo() { return {3, 10, 15}; }
280 
281 TEST(AlignmentDeathTest, Log2) {
282   EXPECT_DEATH(Log2(MaybeAlign(0)), ".* should be defined");
283 }
284 
285 TEST(AlignmentDeathTest, CantConvertUnsetMaybe) {
286   EXPECT_DEATH((MaybeAlign(0).getValue()), ".*");
287 }
288 
289 TEST(AlignmentDeathTest, Division) {
290   EXPECT_DEATH(Align(1) / 2, "Can't halve byte alignment");
291   EXPECT_DEATH(MaybeAlign(1) / 2, "Can't halve byte alignment");
292 
293   EXPECT_DEATH(Align(8) / 0, "Divisor must be positive and a power of 2");
294   EXPECT_DEATH(Align(8) / 3, "Divisor must be positive and a power of 2");
295 }
296 
297 TEST(AlignmentDeathTest, InvalidCTors) {
298   EXPECT_DEATH((Align(0)), "Value must not be 0");
299   for (uint64_t Value : getNonPowerOfTwo()) {
300     EXPECT_DEATH((Align(Value)), "Alignment is not a power of 2");
301     EXPECT_DEATH((MaybeAlign(Value)),
302                  "Alignment is neither 0 nor a power of 2");
303   }
304 }
305 
306 TEST(AlignmentDeathTest, ComparisonsWithZero) {
307   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
308     EXPECT_DEATH((void)(Align(Value) == 0), ".* should be defined");
309     EXPECT_DEATH((void)(Align(Value) != 0), ".* should be defined");
310     EXPECT_DEATH((void)(Align(Value) >= 0), ".* should be defined");
311     EXPECT_DEATH((void)(Align(Value) <= 0), ".* should be defined");
312     EXPECT_DEATH((void)(Align(Value) > 0), ".* should be defined");
313     EXPECT_DEATH((void)(Align(Value) < 0), ".* should be defined");
314   }
315 }
316 
317 TEST(AlignmentDeathTest, CompareMaybeAlignToZero) {
318   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
319     // MaybeAlign is allowed to be == or != 0
320     (void)(MaybeAlign(Value) == 0);
321     (void)(MaybeAlign(Value) != 0);
322     EXPECT_DEATH((void)(MaybeAlign(Value) >= 0), ".* should be defined");
323     EXPECT_DEATH((void)(MaybeAlign(Value) <= 0), ".* should be defined");
324     EXPECT_DEATH((void)(MaybeAlign(Value) > 0), ".* should be defined");
325     EXPECT_DEATH((void)(MaybeAlign(Value) < 0), ".* should be defined");
326   }
327 }
328 
329 TEST(AlignmentDeathTest, CompareAlignToUndefMaybeAlign) {
330   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
331     EXPECT_DEATH((void)(Align(Value) == MaybeAlign(0)), ".* should be defined");
332     EXPECT_DEATH((void)(Align(Value) != MaybeAlign(0)), ".* should be defined");
333     EXPECT_DEATH((void)(Align(Value) >= MaybeAlign(0)), ".* should be defined");
334     EXPECT_DEATH((void)(Align(Value) <= MaybeAlign(0)), ".* should be defined");
335     EXPECT_DEATH((void)(Align(Value) > MaybeAlign(0)), ".* should be defined");
336     EXPECT_DEATH((void)(Align(Value) < MaybeAlign(0)), ".* should be defined");
337   }
338 }
339 
340 #endif // NDEBUG
341 
342 } // end anonymous namespace
343 
344 #ifdef _MSC_VER
345 #pragma warning(pop)
346 #endif
347