xref: /llvm-project/llvm/unittests/Support/AlignmentTest.cpp (revision aa8feeefd3ac6c78ee8f67bf033976fc7d68bc6d)
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) { EXPECT_EQ(Align().value(), 1ULL); }
54 
55 TEST(AlignmentTest, MaybeAlignDefaultCTor) { EXPECT_FALSE(MaybeAlign()); }
56 
57 TEST(AlignmentTest, ValidCTors) {
58   for (uint64_t Value : getValidAlignments()) {
59     EXPECT_EQ(Align(Value).value(), Value);
60     EXPECT_EQ((*MaybeAlign(Value)).value(), Value);
61   }
62 }
63 
64 TEST(AlignmentTest, CheckMaybeAlignHasValue) {
65   EXPECT_TRUE(MaybeAlign(1));
66   EXPECT_TRUE(MaybeAlign(1).has_value());
67   EXPECT_FALSE(MaybeAlign(0));
68   EXPECT_FALSE(MaybeAlign(0).has_value());
69   EXPECT_FALSE(MaybeAlign());
70   EXPECT_FALSE(MaybeAlign().has_value());
71 }
72 
73 TEST(AlignmentTest, Division) {
74   for (uint64_t Value : getValidAlignments()) {
75     if (Value > 1) {
76       EXPECT_EQ(Align(Value).previous(), Value / 2);
77     }
78   }
79 }
80 
81 TEST(AlignmentTest, AlignTo) {
82   struct {
83     uint64_t alignment;
84     uint64_t offset;
85     uint64_t rounded;
86     const void *forgedAddr() const {
87       //  A value of any integral or enumeration type can be converted to a
88       //  pointer type.
89       return reinterpret_cast<const void *>(offset);
90     }
91   } kTests[] = {
92       // Align
93       {1, 0, 0}, {1, 1, 1},   {1, 5, 5}, {2, 0, 0}, {2, 1, 2}, {2, 2, 2},
94       {2, 7, 8}, {2, 16, 16}, {4, 0, 0}, {4, 1, 4}, {4, 4, 4}, {4, 6, 8},
95   };
96   for (const auto &T : kTests) {
97     Align A = Align(T.alignment);
98     EXPECT_EQ(alignTo(T.offset, A), T.rounded);
99     EXPECT_EQ(alignAddr(T.forgedAddr(), A), T.rounded);
100   }
101 }
102 
103 TEST(AlignmentTest, AlignToWithSkew) {
104   EXPECT_EQ(alignTo(5, Align(8), 0), alignTo(5, Align(8)));
105   EXPECT_EQ(alignTo(5, Align(8), 7), 7U);
106   EXPECT_EQ(alignTo(17, Align(8), 1), 17U);
107   EXPECT_EQ(alignTo(~0LL, Align(8), 3), 3U);
108 }
109 
110 TEST(AlignmentTest, Log2) {
111   for (uint64_t Value : getValidAlignments()) {
112     EXPECT_EQ(Log2(Align(Value)), Log2_64(Value));
113   }
114 }
115 
116 TEST(AlignmentTest, MinAlign) {
117   struct {
118     uint64_t A;
119     uint64_t B;
120     uint64_t MinAlign;
121   } kTests[] = {
122       {1, 2, 1},
123       {8, 4, 4},
124   };
125   for (const auto &T : kTests) {
126     EXPECT_EQ(MinAlign(T.A, T.B), T.MinAlign);
127     EXPECT_EQ(commonAlignment(Align(T.A), Align(T.B)), T.MinAlign);
128   }
129 }
130 
131 TEST(AlignmentTest, Encode_Decode) {
132   for (uint64_t Value : getValidAlignments()) {
133     {
134       Align Actual(Value);
135       Align Expected = *decodeMaybeAlign(encode(Actual));
136       EXPECT_EQ(Expected, Actual);
137     }
138     {
139       MaybeAlign Actual(Value);
140       MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
141       EXPECT_EQ(Expected, Actual);
142     }
143   }
144   MaybeAlign Actual(0);
145   MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
146   EXPECT_EQ(Expected, Actual);
147 }
148 
149 TEST(AlignmentTest, isAligned_isAddrAligned) {
150   struct {
151     uint64_t alignment;
152     uint64_t offset;
153     bool isAligned;
154     const void *forgedAddr() const {
155       //  A value of any integral or enumeration type can be converted to a
156       //  pointer type.
157       return reinterpret_cast<const void *>(offset);
158     }
159   } kTests[] = {
160       {1, 0, true},  {1, 1, true},  {1, 5, true},  {2, 0, true},
161       {2, 1, false}, {2, 2, true},  {2, 7, false}, {2, 16, true},
162       {4, 0, true},  {4, 1, false}, {4, 4, true},  {4, 6, false},
163   };
164   for (const auto &T : kTests) {
165     MaybeAlign A(T.alignment);
166     // Test Align
167     if (A) {
168       EXPECT_EQ(isAligned(*A, T.offset), T.isAligned);
169       EXPECT_EQ(isAddrAligned(*A, T.forgedAddr()), T.isAligned);
170     }
171   }
172 }
173 
174 TEST(AlignmentTest, offsetToAlignment) {
175   struct {
176     uint64_t alignment;
177     uint64_t offset;
178     uint64_t alignedOffset;
179     const void *forgedAddr() const {
180       //  A value of any integral or enumeration type can be converted to a
181       //  pointer type.
182       return reinterpret_cast<const void *>(offset);
183     }
184   } kTests[] = {
185       {1, 0, 0}, {1, 1, 0},  {1, 5, 0}, {2, 0, 0}, {2, 1, 1}, {2, 2, 0},
186       {2, 7, 1}, {2, 16, 0}, {4, 0, 0}, {4, 1, 3}, {4, 4, 0}, {4, 6, 2},
187   };
188   for (const auto &T : kTests) {
189     const Align A(T.alignment);
190     EXPECT_EQ(offsetToAlignment(T.offset, A), T.alignedOffset);
191     EXPECT_EQ(offsetToAlignedAddr(T.forgedAddr(), A), T.alignedOffset);
192   }
193 }
194 
195 TEST(AlignmentTest, AlignComparisons) {
196   std::vector<uint64_t> ValidAlignments = getValidAlignments();
197   std::sort(ValidAlignments.begin(), ValidAlignments.end());
198   for (size_t I = 1; I < ValidAlignments.size(); ++I) {
199     assert(I >= 1);
200     const Align A(ValidAlignments[I - 1]);
201     const Align B(ValidAlignments[I]);
202     EXPECT_EQ(A, A);
203     EXPECT_NE(A, B);
204     EXPECT_LT(A, B);
205     EXPECT_GT(B, A);
206     EXPECT_LE(A, B);
207     EXPECT_GE(B, A);
208     EXPECT_LE(A, A);
209     EXPECT_GE(A, A);
210 
211     EXPECT_EQ(A, A.value());
212     EXPECT_NE(A, B.value());
213     EXPECT_LT(A, B.value());
214     EXPECT_GT(B, A.value());
215     EXPECT_LE(A, B.value());
216     EXPECT_GE(B, A.value());
217     EXPECT_LE(A, A.value());
218     EXPECT_GE(A, A.value());
219 
220     EXPECT_EQ(std::max(A, B), B);
221     EXPECT_EQ(std::min(A, B), A);
222 
223     const MaybeAlign MA(ValidAlignments[I - 1]);
224     const MaybeAlign MB(ValidAlignments[I]);
225     EXPECT_EQ(MA, MA);
226     EXPECT_NE(MA, MB);
227 
228     EXPECT_EQ(std::max(A, B), B);
229     EXPECT_EQ(std::min(A, B), A);
230   }
231 }
232 
233 TEST(AlignmentTest, AssumeAligned) {
234   EXPECT_EQ(assumeAligned(0), Align(1));
235   EXPECT_EQ(assumeAligned(0), Align());
236   EXPECT_EQ(assumeAligned(1), Align(1));
237   EXPECT_EQ(assumeAligned(1), Align());
238 }
239 
240 // Death tests reply on assert which is disabled in release mode.
241 #ifndef NDEBUG
242 
243 // We use a subset of valid alignments for DEATH_TESTs as they are particularly
244 // slow.
245 std::vector<uint64_t> getValidAlignmentsForDeathTest() {
246   return {1, 1ULL << 31, 1ULL << 63};
247 }
248 
249 std::vector<uint64_t> getNonPowerOfTwo() { return {3, 10, 15}; }
250 
251 TEST(AlignmentDeathTest, CantConvertUnsetMaybe) {
252   EXPECT_DEATH((*MaybeAlign(0)), ".*");
253 }
254 
255 TEST(AlignmentDeathTest, InvalidCTors) {
256   EXPECT_DEATH((Align(0)), "Value must not be 0");
257   for (uint64_t Value : getNonPowerOfTwo()) {
258     EXPECT_DEATH((Align(Value)), "Alignment is not a power of 2");
259     EXPECT_DEATH((MaybeAlign(Value)),
260                  "Alignment is neither 0 nor a power of 2");
261   }
262 }
263 
264 TEST(AlignmentDeathTest, ComparisonsWithZero) {
265   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
266     EXPECT_DEATH((void)(Align(Value) == 0), ".* should be defined");
267     EXPECT_DEATH((void)(Align(Value) != 0), ".* should be defined");
268     EXPECT_DEATH((void)(Align(Value) >= 0), ".* should be defined");
269     EXPECT_DEATH((void)(Align(Value) <= 0), ".* should be defined");
270     EXPECT_DEATH((void)(Align(Value) > 0), ".* should be defined");
271     EXPECT_DEATH((void)(Align(Value) < 0), ".* should be defined");
272   }
273 }
274 
275 TEST(AlignmentDeathTest, AlignAddr) {
276   const void *const unaligned_high_ptr =
277       reinterpret_cast<const void *>(std::numeric_limits<uintptr_t>::max() - 1);
278   EXPECT_DEATH(alignAddr(unaligned_high_ptr, Align(16)), "Overflow");
279 }
280 
281 #endif // NDEBUG
282 
283 } // end anonymous namespace
284 
285 #ifdef _MSC_VER
286 #pragma warning(pop)
287 #endif
288