xref: /llvm-project/llvm/unittests/Support/AlignmentTest.cpp (revision 1baf1fc27640b6e4b7a83484f4d99e7e6dbee571)
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) {
56   EXPECT_FALSE(MaybeAlign().hasValue());
57 }
58 
59 TEST(AlignmentTest, ValidCTors) {
60   for (uint64_t Value : getValidAlignments()) {
61     EXPECT_EQ(Align(Value).value(), Value);
62     EXPECT_EQ((*MaybeAlign(Value)).value(), Value);
63   }
64 }
65 
66 TEST(AlignmentTest, CheckMaybeAlignHasValue) {
67   EXPECT_TRUE(MaybeAlign(1));
68   EXPECT_TRUE(MaybeAlign(1).hasValue());
69   EXPECT_FALSE(MaybeAlign(0));
70   EXPECT_FALSE(MaybeAlign(0).hasValue());
71   EXPECT_FALSE(MaybeAlign());
72   EXPECT_FALSE(MaybeAlign().hasValue());
73 }
74 
75 TEST(AlignmentTest, Division) {
76   for (uint64_t Value : getValidAlignments()) {
77     if (Value > 1) {
78       EXPECT_EQ(Align(Value).previous(), Value / 2);
79     }
80   }
81 }
82 
83 TEST(AlignmentTest, AlignTo) {
84   struct {
85     uint64_t alignment;
86     uint64_t offset;
87     uint64_t rounded;
88     const void *forgedAddr() const {
89       //  A value of any integral or enumeration type can be converted to a
90       //  pointer type.
91       return reinterpret_cast<const void *>(offset);
92     }
93   } kTests[] = {
94       // Align
95       {1, 0, 0}, {1, 1, 1},   {1, 5, 5}, {2, 0, 0}, {2, 1, 2}, {2, 2, 2},
96       {2, 7, 8}, {2, 16, 16}, {4, 0, 0}, {4, 1, 4}, {4, 4, 4}, {4, 6, 8},
97   };
98   for (const auto &T : kTests) {
99     Align A = Align(T.alignment);
100     EXPECT_EQ(alignTo(T.offset, A), T.rounded);
101     EXPECT_EQ(alignAddr(T.forgedAddr(), A), T.rounded);
102   }
103 }
104 
105 TEST(AlignmentTest, AlignToWithSkew) {
106   EXPECT_EQ(alignTo(5, Align(8), 0), alignTo(5, Align(8)));
107   EXPECT_EQ(alignTo(5, Align(8), 7), 7U);
108   EXPECT_EQ(alignTo(17, Align(8), 1), 17U);
109   EXPECT_EQ(alignTo(~0LL, Align(8), 3), 3U);
110 }
111 
112 TEST(AlignmentTest, Log2) {
113   for (uint64_t Value : getValidAlignments()) {
114     EXPECT_EQ(Log2(Align(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       {1, 2, 1},
125       {8, 4, 4},
126   };
127   for (const auto &T : kTests) {
128     EXPECT_EQ(MinAlign(T.A, T.B), T.MinAlign);
129     EXPECT_EQ(commonAlignment(Align(T.A), Align(T.B)), T.MinAlign);
130   }
131 }
132 
133 TEST(AlignmentTest, Encode_Decode) {
134   for (uint64_t Value : getValidAlignments()) {
135     {
136       Align Actual(Value);
137       Align Expected = decodeMaybeAlign(encode(Actual)).getValue();
138       EXPECT_EQ(Expected, Actual);
139     }
140     {
141       MaybeAlign Actual(Value);
142       MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
143       EXPECT_EQ(Expected, Actual);
144     }
145   }
146   MaybeAlign Actual(0);
147   MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
148   EXPECT_EQ(Expected, Actual);
149 }
150 
151 TEST(AlignmentTest, isAligned_isAddrAligned) {
152   struct {
153     uint64_t alignment;
154     uint64_t offset;
155     bool isAligned;
156     const void *forgedAddr() const {
157       //  A value of any integral or enumeration type can be converted to a
158       //  pointer type.
159       return reinterpret_cast<const void *>(offset);
160     }
161   } kTests[] = {
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 Align
169     if (A) {
170       EXPECT_EQ(isAligned(A.getValue(), T.offset), T.isAligned);
171       EXPECT_EQ(isAddrAligned(A.getValue(), T.forgedAddr()), T.isAligned);
172     }
173   }
174 }
175 
176 TEST(AlignmentTest, offsetToAlignment) {
177   struct {
178     uint64_t alignment;
179     uint64_t offset;
180     uint64_t alignedOffset;
181     const void *forgedAddr() const {
182       //  A value of any integral or enumeration type can be converted to a
183       //  pointer type.
184       return reinterpret_cast<const void *>(offset);
185     }
186   } kTests[] = {
187       {1, 0, 0}, {1, 1, 0},  {1, 5, 0}, {2, 0, 0}, {2, 1, 1}, {2, 2, 0},
188       {2, 7, 1}, {2, 16, 0}, {4, 0, 0}, {4, 1, 3}, {4, 4, 0}, {4, 6, 2},
189   };
190   for (const auto &T : kTests) {
191     const Align A(T.alignment);
192     EXPECT_EQ(offsetToAlignment(T.offset, A), T.alignedOffset);
193     EXPECT_EQ(offsetToAlignedAddr(T.forgedAddr(), A), T.alignedOffset);
194   }
195 }
196 
197 TEST(AlignmentTest, AlignComparisons) {
198   std::vector<uint64_t> ValidAlignments = getValidAlignments();
199   std::sort(ValidAlignments.begin(), ValidAlignments.end());
200   for (size_t I = 1; I < ValidAlignments.size(); ++I) {
201     assert(I >= 1);
202     const Align A(ValidAlignments[I - 1]);
203     const Align B(ValidAlignments[I]);
204     EXPECT_EQ(A, A);
205     EXPECT_NE(A, B);
206     EXPECT_LT(A, B);
207     EXPECT_GT(B, A);
208     EXPECT_LE(A, B);
209     EXPECT_GE(B, A);
210     EXPECT_LE(A, A);
211     EXPECT_GE(A, A);
212 
213     EXPECT_EQ(A, A.value());
214     EXPECT_NE(A, B.value());
215     EXPECT_LT(A, B.value());
216     EXPECT_GT(B, A.value());
217     EXPECT_LE(A, B.value());
218     EXPECT_GE(B, A.value());
219     EXPECT_LE(A, A.value());
220     EXPECT_GE(A, A.value());
221 
222     EXPECT_EQ(std::max(A, B), B);
223     EXPECT_EQ(std::min(A, B), A);
224 
225     const MaybeAlign MA(ValidAlignments[I - 1]);
226     const MaybeAlign MB(ValidAlignments[I]);
227     EXPECT_EQ(MA, MA);
228     EXPECT_NE(MA, MB);
229 
230     EXPECT_EQ(std::max(A, B), B);
231     EXPECT_EQ(std::min(A, B), A);
232   }
233 }
234 
235 TEST(AlignmentTest, AssumeAligned) {
236   EXPECT_EQ(assumeAligned(0), Align(1));
237   EXPECT_EQ(assumeAligned(0), Align());
238   EXPECT_EQ(assumeAligned(1), Align(1));
239   EXPECT_EQ(assumeAligned(1), Align());
240 }
241 
242 // Death tests reply on assert which is disabled in release mode.
243 #ifndef NDEBUG
244 
245 // We use a subset of valid alignments for DEATH_TESTs as they are particularly
246 // slow.
247 std::vector<uint64_t> getValidAlignmentsForDeathTest() {
248   return {1, 1ULL << 31, 1ULL << 63};
249 }
250 
251 std::vector<uint64_t> getNonPowerOfTwo() { return {3, 10, 15}; }
252 
253 TEST(AlignmentDeathTest, CantConvertUnsetMaybe) {
254   EXPECT_DEATH((MaybeAlign(0).getValue()), ".*");
255 }
256 
257 TEST(AlignmentDeathTest, InvalidCTors) {
258   EXPECT_DEATH((Align(0)), "Value must not be 0");
259   for (uint64_t Value : getNonPowerOfTwo()) {
260     EXPECT_DEATH((Align(Value)), "Alignment is not a power of 2");
261     EXPECT_DEATH((MaybeAlign(Value)),
262                  "Alignment is neither 0 nor a power of 2");
263   }
264 }
265 
266 TEST(AlignmentDeathTest, ComparisonsWithZero) {
267   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
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     EXPECT_DEATH((void)(Align(Value) > 0), ".* should be defined");
273     EXPECT_DEATH((void)(Align(Value) < 0), ".* should be defined");
274   }
275 }
276 
277 TEST(AlignmentDeathTest, AlignAddr) {
278   const void *const unaligned_high_ptr =
279       reinterpret_cast<const void *>(std::numeric_limits<uintptr_t>::max() - 1);
280   EXPECT_DEATH(alignAddr(unaligned_high_ptr, Align(16)), "Overflow");
281 }
282 
283 #endif // NDEBUG
284 
285 } // end anonymous namespace
286 
287 #ifdef _MSC_VER
288 #pragma warning(pop)
289 #endif
290