xref: /llvm-project/llvm/unittests/Support/AlignmentTest.cpp (revision 3361a364e64c815ede2fe6dfe4e8016637c16b0b)
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, Encode_Decode) {
117   for (uint64_t Value : getValidAlignments()) {
118     {
119       Align Actual(Value);
120       Align Expected = *decodeMaybeAlign(encode(Actual));
121       EXPECT_EQ(Expected, Actual);
122     }
123     {
124       MaybeAlign Actual(Value);
125       MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
126       EXPECT_EQ(Expected, Actual);
127     }
128   }
129   MaybeAlign Actual(0);
130   MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
131   EXPECT_EQ(Expected, Actual);
132 }
133 
134 TEST(AlignmentTest, isAligned_isAddrAligned) {
135   struct {
136     uint64_t alignment;
137     uint64_t offset;
138     bool isAligned;
139     const void *forgedAddr() const {
140       //  A value of any integral or enumeration type can be converted to a
141       //  pointer type.
142       return reinterpret_cast<const void *>(offset);
143     }
144   } kTests[] = {
145       {1, 0, true},  {1, 1, true},  {1, 5, true},  {2, 0, true},
146       {2, 1, false}, {2, 2, true},  {2, 7, false}, {2, 16, true},
147       {4, 0, true},  {4, 1, false}, {4, 4, true},  {4, 6, false},
148   };
149   for (const auto &T : kTests) {
150     MaybeAlign A(T.alignment);
151     // Test Align
152     if (A) {
153       EXPECT_EQ(isAligned(A.getValue(), T.offset), T.isAligned);
154       EXPECT_EQ(isAddrAligned(A.getValue(), T.forgedAddr()), T.isAligned);
155     }
156   }
157 }
158 
159 TEST(AlignmentTest, offsetToAlignment) {
160   struct {
161     uint64_t alignment;
162     uint64_t offset;
163     uint64_t alignedOffset;
164     const void *forgedAddr() const {
165       //  A value of any integral or enumeration type can be converted to a
166       //  pointer type.
167       return reinterpret_cast<const void *>(offset);
168     }
169   } kTests[] = {
170       {1, 0, 0}, {1, 1, 0},  {1, 5, 0}, {2, 0, 0}, {2, 1, 1}, {2, 2, 0},
171       {2, 7, 1}, {2, 16, 0}, {4, 0, 0}, {4, 1, 3}, {4, 4, 0}, {4, 6, 2},
172   };
173   for (const auto &T : kTests) {
174     const Align A(T.alignment);
175     EXPECT_EQ(offsetToAlignment(T.offset, A), T.alignedOffset);
176     EXPECT_EQ(offsetToAlignedAddr(T.forgedAddr(), A), T.alignedOffset);
177   }
178 }
179 
180 TEST(AlignmentTest, AlignComparisons) {
181   std::vector<uint64_t> ValidAlignments = getValidAlignments();
182   std::sort(ValidAlignments.begin(), ValidAlignments.end());
183   for (size_t I = 1; I < ValidAlignments.size(); ++I) {
184     assert(I >= 1);
185     const Align A(ValidAlignments[I - 1]);
186     const Align B(ValidAlignments[I]);
187     EXPECT_EQ(A, A);
188     EXPECT_NE(A, B);
189     EXPECT_LT(A, B);
190     EXPECT_GT(B, A);
191     EXPECT_LE(A, B);
192     EXPECT_GE(B, A);
193     EXPECT_LE(A, A);
194     EXPECT_GE(A, A);
195 
196     EXPECT_EQ(A, A.value());
197     EXPECT_NE(A, B.value());
198     EXPECT_LT(A, B.value());
199     EXPECT_GT(B, A.value());
200     EXPECT_LE(A, B.value());
201     EXPECT_GE(B, A.value());
202     EXPECT_LE(A, A.value());
203     EXPECT_GE(A, A.value());
204 
205     EXPECT_EQ(std::max(A, B), B);
206     EXPECT_EQ(std::min(A, B), A);
207 
208     const MaybeAlign MA(ValidAlignments[I - 1]);
209     const MaybeAlign MB(ValidAlignments[I]);
210     EXPECT_EQ(MA, MA);
211     EXPECT_NE(MA, MB);
212 
213     EXPECT_EQ(std::max(A, B), B);
214     EXPECT_EQ(std::min(A, B), A);
215   }
216 }
217 
218 TEST(AlignmentTest, AssumeAligned) {
219   EXPECT_EQ(assumeAligned(0), Align(1));
220   EXPECT_EQ(assumeAligned(0), Align());
221   EXPECT_EQ(assumeAligned(1), Align(1));
222   EXPECT_EQ(assumeAligned(1), Align());
223 }
224 
225 // Death tests reply on assert which is disabled in release mode.
226 #ifndef NDEBUG
227 
228 // We use a subset of valid alignments for DEATH_TESTs as they are particularly
229 // slow.
230 std::vector<uint64_t> getValidAlignmentsForDeathTest() {
231   return {1, 1ULL << 31, 1ULL << 63};
232 }
233 
234 std::vector<uint64_t> getNonPowerOfTwo() { return {3, 10, 15}; }
235 
236 TEST(AlignmentDeathTest, CantConvertUnsetMaybe) {
237   EXPECT_DEATH((*MaybeAlign(0)), ".*");
238 }
239 
240 TEST(AlignmentDeathTest, InvalidCTors) {
241   EXPECT_DEATH((Align(0)), "Value must not be 0");
242   for (uint64_t Value : getNonPowerOfTwo()) {
243     EXPECT_DEATH((Align(Value)), "Alignment is not a power of 2");
244     EXPECT_DEATH((MaybeAlign(Value)),
245                  "Alignment is neither 0 nor a power of 2");
246   }
247 }
248 
249 TEST(AlignmentDeathTest, ComparisonsWithZero) {
250   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
251     EXPECT_DEATH((void)(Align(Value) == 0), ".* should be defined");
252     EXPECT_DEATH((void)(Align(Value) != 0), ".* should be defined");
253     EXPECT_DEATH((void)(Align(Value) >= 0), ".* should be defined");
254     EXPECT_DEATH((void)(Align(Value) <= 0), ".* should be defined");
255     EXPECT_DEATH((void)(Align(Value) > 0), ".* should be defined");
256     EXPECT_DEATH((void)(Align(Value) < 0), ".* should be defined");
257   }
258 }
259 
260 TEST(AlignmentDeathTest, AlignAddr) {
261   const void *const unaligned_high_ptr =
262       reinterpret_cast<const void *>(std::numeric_limits<uintptr_t>::max() - 1);
263   EXPECT_DEATH(alignAddr(unaligned_high_ptr, Align(16)), "Overflow");
264 }
265 
266 #endif // NDEBUG
267 
268 } // end anonymous namespace
269 
270 #ifdef _MSC_VER
271 #pragma warning(pop)
272 #endif
273