llvm/unittests/Support/AlignmentTest.cpp

   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 "llvm/ADT/STLExtras.h"
  11 #include "gtest/gtest.h"
  12
  13 #include <vector>
  14
  15 #ifdef _MSC_VER
  16 // Disable warnings about potential divide by 0.
  17 #pragma warning(push)
  18 #pragma warning(disable : 4723)
  19 #endif
  20
  21 using namespace llvm;
  22
  23 namespace {
  24
  25 TEST(AlignmentTest, AlignOfConstant) {
  26   EXPECT_EQ(Align::Of<uint8_t>(), Align(alignof(uint8_t)));
  27   EXPECT_EQ(Align::Of<uint16_t>(), Align(alignof(uint16_t)));
  28   EXPECT_EQ(Align::Of<uint32_t>(), Align(alignof(uint32_t)));
  29   EXPECT_EQ(Align::Of<uint64_t>(), Align(alignof(uint64_t)));
  30 }
  31
  32 TEST(AlignmentTest, AlignConstant) {
  33   EXPECT_EQ(Align::Constant<1>(), Align(1));
  34   EXPECT_EQ(Align::Constant<2>(), Align(2));
  35   EXPECT_EQ(Align::Constant<4>(), Align(4));
  36   EXPECT_EQ(Align::Constant<8>(), Align(8));
  37   EXPECT_EQ(Align::Constant<16>(), Align(16));
  38   EXPECT_EQ(Align::Constant<32>(), Align(32));
  39   EXPECT_EQ(Align::Constant<64>(), Align(64));
  40 }
  41
  42 TEST(AlignmentTest, AlignConstexprConstant) {
  43   constexpr Align kConstantAlign = Align::Of<uint64_t>();
  44   EXPECT_EQ(Align(alignof(uint64_t)), kConstantAlign);
  45 }
  46
  47 std::vector<uint64_t> getValidAlignments() {
  48   std::vector<uint64_t> Out;
  49   for (size_t Shift = 0; Shift < 64; ++Shift)
  50     Out.push_back(1ULL << Shift);
  51   return Out;
  52 }
  53
  54 TEST(AlignmentTest, AlignDefaultCTor) { EXPECT_EQ(Align().value(), 1ULL); }
  55
  56 TEST(AlignmentTest, MaybeAlignDefaultCTor) { EXPECT_FALSE(MaybeAlign()); }
  57
  58 TEST(AlignmentTest, ValidCTors) {
  59   for (uint64_t Value : getValidAlignments()) {
  60     EXPECT_EQ(Align(Value).value(), Value);
  61     EXPECT_EQ((*MaybeAlign(Value)).value(), Value);
  62   }
  63 }
  64
  65 TEST(AlignmentTest, CheckMaybeAlignHasValue) {
  66   EXPECT_TRUE(MaybeAlign(1));
  67   EXPECT_TRUE(MaybeAlign(1).has_value());
  68   EXPECT_FALSE(MaybeAlign(0));
  69   EXPECT_FALSE(MaybeAlign(0).has_value());
  70   EXPECT_FALSE(MaybeAlign());
  71   EXPECT_FALSE(MaybeAlign().has_value());
  72 }
  73
  74 TEST(AlignmentTest, Division) {
  75   for (uint64_t Value : getValidAlignments()) {
  76     if (Value > 1) {
  77       EXPECT_EQ(Align(Value).previous(), Value / 2);
  78     }
  79   }
  80 }
  81
  82 TEST(AlignmentTest, AlignTo) {
  83   struct {
  84     uint64_t alignment;
  85     uint64_t offset;
  86     uint64_t rounded;
  87     const void *forgedAddr() const {
  88       //  A value of any integral or enumeration type can be converted to a
  89       //  pointer type.
  90       return reinterpret_cast<const void *>(offset);
  91     }
  92   } kTests[] = {
  93       // Align
  94       {1, 0, 0}, {1, 1, 1},   {1, 5, 5}, {2, 0, 0}, {2, 1, 2}, {2, 2, 2},
  95       {2, 7, 8}, {2, 16, 16}, {4, 0, 0}, {4, 1, 4}, {4, 4, 4}, {4, 6, 8},
  96   };
  97   for (const auto &T : kTests) {
  98     Align A = Align(T.alignment);
  99     EXPECT_EQ(alignTo(T.offset, A), T.rounded);
 100     EXPECT_EQ(alignAddr(T.forgedAddr(), A), T.rounded);
 101   }
 102 }
 103
 104 TEST(AlignmentTest, AlignToWithSkew) {
 105   EXPECT_EQ(alignTo(5, Align(8), 0), alignTo(5, Align(8)));
 106   EXPECT_EQ(alignTo(5, Align(8), 7), 7U);
 107   EXPECT_EQ(alignTo(17, Align(8), 1), 17U);
 108   EXPECT_EQ(alignTo(~0LL, Align(8), 3), 3U);
 109 }
 110
 111 TEST(AlignmentTest, Log2) {
 112   for (uint64_t Value : getValidAlignments()) {
 113     EXPECT_EQ(Log2(Align(Value)), Log2_64(Value));
 114   }
 115 }
 116
 117 TEST(AlignmentTest, Encode_Decode) {
 118   for (uint64_t Value : getValidAlignments()) {
 119     {
 120       Align Actual(Value);
 121       Align Expected = *decodeMaybeAlign(encode(Actual));
 122       EXPECT_EQ(Expected, Actual);
 123     }
 124     {
 125       MaybeAlign Actual(Value);
 126       MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
 127       EXPECT_EQ(Expected, Actual);
 128     }
 129   }
 130   MaybeAlign Actual(0);
 131   MaybeAlign Expected = decodeMaybeAlign(encode(Actual));
 132   EXPECT_EQ(Expected, Actual);
 133 }
 134
 135 TEST(AlignmentTest, isAligned_isAddrAligned) {
 136   struct {
 137     uint64_t alignment;
 138     uint64_t offset;
 139     bool isAligned;
 140     const void *forgedAddr() const {
 141       //  A value of any integral or enumeration type can be converted to a
 142       //  pointer type.
 143       return reinterpret_cast<const void *>(offset);
 144     }
 145   } kTests[] = {
 146       {1, 0, true},  {1, 1, true},  {1, 5, true},  {2, 0, true},
 147       {2, 1, false}, {2, 2, true},  {2, 7, false}, {2, 16, true},
 148       {4, 0, true},  {4, 1, false}, {4, 4, true},  {4, 6, false},
 149   };
 150   for (const auto &T : kTests) {
 151     MaybeAlign A(T.alignment);
 152     // Test Align
 153     if (A) {
 154       EXPECT_EQ(isAligned(A.value(), T.offset), T.isAligned);
 155       EXPECT_EQ(isAddrAligned(A.value(), T.forgedAddr()), T.isAligned);
 156     }
 157   }
 158 }
 159
 160 TEST(AlignmentTest, offsetToAlignment) {
 161   struct {
 162     uint64_t alignment;
 163     uint64_t offset;
 164     uint64_t alignedOffset;
 165     const void *forgedAddr() const {
 166       //  A value of any integral or enumeration type can be converted to a
 167       //  pointer type.
 168       return reinterpret_cast<const void *>(offset);
 169     }
 170   } kTests[] = {
 171       {1, 0, 0}, {1, 1, 0},  {1, 5, 0}, {2, 0, 0}, {2, 1, 1}, {2, 2, 0},
 172       {2, 7, 1}, {2, 16, 0}, {4, 0, 0}, {4, 1, 3}, {4, 4, 0}, {4, 6, 2},
 173   };
 174   for (const auto &T : kTests) {
 175     const Align A(T.alignment);
 176     EXPECT_EQ(offsetToAlignment(T.offset, A), T.alignedOffset);
 177     EXPECT_EQ(offsetToAlignedAddr(T.forgedAddr(), A), T.alignedOffset);
 178   }
 179 }
 180
 181 TEST(AlignmentTest, AlignComparisons) {
 182   std::vector<uint64_t> ValidAlignments = getValidAlignments();
 183   llvm::sort(ValidAlignments);
 184   for (size_t I = 1; I < ValidAlignments.size(); ++I) {
 185     assert(I >= 1);
 186     const Align A(ValidAlignments[I - 1]);
 187     const Align B(ValidAlignments[I]);
 188     EXPECT_EQ(A, A);
 189     EXPECT_NE(A, B);
 190     EXPECT_LT(A, B);
 191     EXPECT_GT(B, A);
 192     EXPECT_LE(A, B);
 193     EXPECT_GE(B, A);
 194     EXPECT_LE(A, A);
 195     EXPECT_GE(A, A);
 196
 197     EXPECT_EQ(A, A.value());
 198     EXPECT_NE(A, B.value());
 199     EXPECT_LT(A, B.value());
 200     EXPECT_GT(B, A.value());
 201     EXPECT_LE(A, B.value());
 202     EXPECT_GE(B, A.value());
 203     EXPECT_LE(A, A.value());
 204     EXPECT_GE(A, A.value());
 205
 206     EXPECT_EQ(std::max(A, B), B);
 207     EXPECT_EQ(std::min(A, B), A);
 208
 209     const MaybeAlign MA(ValidAlignments[I - 1]);
 210     const MaybeAlign MB(ValidAlignments[I]);
 211     EXPECT_EQ(MA, MA);
 212     EXPECT_NE(MA, MB);
 213
 214     EXPECT_EQ(std::max(A, B), B);
 215     EXPECT_EQ(std::min(A, B), A);
 216   }
 217 }
 218
 219 TEST(AlignmentTest, AssumeAligned) {
 220   EXPECT_EQ(assumeAligned(0), Align(1));
 221   EXPECT_EQ(assumeAligned(0), Align());
 222   EXPECT_EQ(assumeAligned(1), Align(1));
 223   EXPECT_EQ(assumeAligned(1), Align());
 224 }
 225
 226 // Death tests reply on assert which is disabled in release mode.
 227 #ifndef NDEBUG
 228
 229 // We use a subset of valid alignments for DEATH_TESTs as they are particularly
 230 // slow.
 231 std::vector<uint64_t> getValidAlignmentsForDeathTest() {
 232   return {1, 1ULL << 31, 1ULL << 63};
 233 }
 234
 235 std::vector<uint64_t> getNonPowerOfTwo() { return {3, 10, 15}; }
 236
 237 TEST(AlignmentDeathTest, CantConvertUnsetMaybe) {
 238   EXPECT_DEATH((*MaybeAlign(0)), ".*");
 239 }
 240
 241 TEST(AlignmentDeathTest, InvalidCTors) {
 242   EXPECT_DEATH((Align(0)), "Value must not be 0");
 243   for (uint64_t Value : getNonPowerOfTwo()) {
 244     EXPECT_DEATH((Align(Value)), "Alignment is not a power of 2");
 245     EXPECT_DEATH((MaybeAlign(Value)),
 246                  "Alignment is neither 0 nor a power of 2");
 247   }
 248 }
 249
 250 TEST(AlignmentDeathTest, ComparisonsWithZero) {
 251   for (uint64_t Value : getValidAlignmentsForDeathTest()) {
 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     EXPECT_DEATH((void)(Align(Value) < 0), ".* should be defined");
 258   }
 259 }
 260
 261 TEST(AlignmentDeathTest, AlignAddr) {
 262   const void *const unaligned_high_ptr =
 263       reinterpret_cast<const void *>(std::numeric_limits<uintptr_t>::max() - 1);
 264   EXPECT_DEATH(alignAddr(unaligned_high_ptr, Align(16)), "Overflow");
 265 }
 266
 267 #endif // NDEBUG
 268
 269 } // end anonymous namespace
 270
 271 #ifdef _MSC_VER
 272 #pragma warning(pop)
 273 #endif