unittests/ADT/HashingTest.cpp

   1 //===- llvm/unittest/ADT/HashingTest.cpp ----------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Hashing.h unit tests.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "gtest/gtest.h"
  15 #include "llvm/ADT/Hashing.h"
  16 #include "llvm/Support/DataTypes.h"
  17 #include <deque>
  18 #include <list>
  19 #include <map>
  20 #include <vector>
  21
  22 namespace llvm {
  23
  24 // Helper for test code to print hash codes.
  25 void PrintTo(const hash_code &code, std::ostream *os) {
  26   *os << static_cast<size_t>(code);
  27 }
  28
  29 // Fake an object that is recognized as hashable data to test super large
  30 // objects.
  31 struct LargeTestInteger { uint64_t arr[8]; };
  32
  33 namespace hashing {
  34 namespace detail {
  35 template <> struct is_hashable_data<LargeTestInteger> : true_type {};
  36 } // namespace detail
  37 } // namespace hashing
  38
  39 } // namespace llvm
  40
  41 using namespace llvm;
  42
  43 namespace {
  44
  45 TEST(HashingTest, HashValueBasicTest) {
  46   int x = 42, y = 43, c = 'x';
  47   void *p = 0;
  48   uint64_t i = 71;
  49   const unsigned ci = 71;
  50   volatile int vi = 71;
  51   const volatile int cvi = 71;
  52   uintptr_t addr = reinterpret_cast<uintptr_t>(&y);
  53   EXPECT_EQ(hash_value(42), hash_value(x));
  54   EXPECT_NE(hash_value(42), hash_value(y));
  55   EXPECT_NE(hash_value(42), hash_value(p));
  56   EXPECT_NE(hash_code::get_null_code(), hash_value(p));
  57   EXPECT_EQ(hash_value(71), hash_value(i));
  58   EXPECT_EQ(hash_value(71), hash_value(ci));
  59   EXPECT_EQ(hash_value(71), hash_value(vi));
  60   EXPECT_EQ(hash_value(71), hash_value(cvi));
  61   EXPECT_EQ(hash_value(c), hash_value('x'));
  62   EXPECT_EQ(hash_value('4'), hash_value('0' + 4));
  63   EXPECT_EQ(hash_value(addr), hash_value(&y));
  64 }
  65
  66 template <typename T, size_t N> T *begin(T (&arr)[N]) { return arr; }
  67 template <typename T, size_t N> T *end(T (&arr)[N]) { return arr + N; }
  68
  69 // Provide a dummy, hashable type designed for easy verification: its hash is
  70 // the same as its value.
  71 struct HashableDummy { size_t value; };
  72 hash_code hash_value(HashableDummy dummy) { return dummy.value; }
  73
  74 TEST(HashingTest, HashCombineRangeBasicTest) {
  75   // Leave this uninitialized in the hope that valgrind will catch bad reads.
  76   int dummy;
  77   hash_code dummy_hash = hash_combine_range(&dummy, &dummy);
  78   EXPECT_NE(hash_code::get_null_code(), dummy_hash);
  79   EXPECT_NE(hash_code::get_invalid_code(), dummy_hash);
  80
  81   const int arr1[] = { 1, 2, 3 };
  82   hash_code arr1_hash = hash_combine_range(begin(arr1), end(arr1));
  83   EXPECT_NE(hash_code::get_null_code(), arr1_hash);
  84   EXPECT_NE(hash_code::get_invalid_code(), arr1_hash);
  85   EXPECT_NE(dummy_hash, arr1_hash);
  86   EXPECT_EQ(arr1_hash, hash_combine_range(begin(arr1), end(arr1)));
  87
  88   const std::vector<int> vec(begin(arr1), end(arr1));
  89   EXPECT_EQ(arr1_hash, hash_combine_range(vec.begin(), vec.end()));
  90
  91   const std::list<int> list(begin(arr1), end(arr1));
  92   EXPECT_EQ(arr1_hash, hash_combine_range(list.begin(), list.end()));
  93
  94   const std::deque<int> deque(begin(arr1), end(arr1));
  95   EXPECT_EQ(arr1_hash, hash_combine_range(deque.begin(), deque.end()));
  96
  97   const int arr2[] = { 3, 2, 1 };
  98   hash_code arr2_hash = hash_combine_range(begin(arr2), end(arr2));
  99   EXPECT_NE(hash_code::get_null_code(), arr2_hash);
 100   EXPECT_NE(hash_code::get_invalid_code(), arr2_hash);
 101   EXPECT_NE(dummy_hash, arr2_hash);
 102   EXPECT_NE(arr1_hash, arr2_hash);
 103
 104   const int arr3[] = { 1, 1, 2, 3 };
 105   hash_code arr3_hash = hash_combine_range(begin(arr3), end(arr3));
 106   EXPECT_NE(hash_code::get_null_code(), arr3_hash);
 107   EXPECT_NE(hash_code::get_invalid_code(), arr3_hash);
 108   EXPECT_NE(dummy_hash, arr3_hash);
 109   EXPECT_NE(arr1_hash, arr3_hash);
 110
 111   const int arr4[] = { 1, 2, 3, 3 };
 112   hash_code arr4_hash = hash_combine_range(begin(arr4), end(arr4));
 113   EXPECT_NE(hash_code::get_null_code(), arr4_hash);
 114   EXPECT_NE(hash_code::get_invalid_code(), arr4_hash);
 115   EXPECT_NE(dummy_hash, arr4_hash);
 116   EXPECT_NE(arr1_hash, arr4_hash);
 117
 118   const size_t arr5[] = { 1, 2, 3 };
 119   const HashableDummy d_arr5[] = { {1}, {2}, {3} };
 120   hash_code arr5_hash = hash_combine_range(begin(arr5), end(arr5));
 121   hash_code d_arr5_hash = hash_combine_range(begin(d_arr5), end(d_arr5));
 122   EXPECT_EQ(arr5_hash, d_arr5_hash);
 123 }
 124
 125 TEST(HashingTest, HashCombineRangeLengthDiff) {
 126   // Test that as only the length varies, we compute different hash codes for
 127   // sequences.
 128   std::map<size_t, size_t> code_to_size;
 129   std::vector<char> all_one_c(256, '\xff');
 130   for (unsigned Idx = 1, Size = all_one_c.size(); Idx < Size; ++Idx) {
 131     hash_code code = hash_combine_range(&all_one_c[0], &all_one_c[0] + Idx);
 132     std::map<size_t, size_t>::iterator
 133       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 134     EXPECT_EQ(Idx, I->second);
 135   }
 136   code_to_size.clear();
 137   std::vector<char> all_zero_c(256, '\0');
 138   for (unsigned Idx = 1, Size = all_zero_c.size(); Idx < Size; ++Idx) {
 139     hash_code code = hash_combine_range(&all_zero_c[0], &all_zero_c[0] + Idx);
 140     std::map<size_t, size_t>::iterator
 141       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 142     EXPECT_EQ(Idx, I->second);
 143   }
 144   code_to_size.clear();
 145   std::vector<unsigned> all_one_int(512, -1);
 146   for (unsigned Idx = 1, Size = all_one_int.size(); Idx < Size; ++Idx) {
 147     hash_code code = hash_combine_range(&all_one_int[0], &all_one_int[0] + Idx);
 148     std::map<size_t, size_t>::iterator
 149       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 150     EXPECT_EQ(Idx, I->second);
 151   }
 152   code_to_size.clear();
 153   std::vector<unsigned> all_zero_int(512, 0);
 154   for (unsigned Idx = 1, Size = all_zero_int.size(); Idx < Size; ++Idx) {
 155     hash_code code = hash_combine_range(&all_zero_int[0], &all_zero_int[0] + Idx);
 156     std::map<size_t, size_t>::iterator
 157       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 158     EXPECT_EQ(Idx, I->second);
 159   }
 160 }
 161
 162 TEST(HashingTest, HashCombineRangeGoldenTest) {
 163   struct { const char *s; uint64_t hash; } golden_data[] = {
 164 #if SIZE_MAX == UINT64_MAX
 165     { "a",                                0xaeb6f9d5517c61f8ULL },
 166     { "ab",                               0x7ab1edb96be496b4ULL },
 167     { "abc",                              0xe38e60bf19c71a3fULL },
 168     { "abcde",                            0xd24461a66de97f6eULL },
 169     { "abcdefgh",                         0x4ef872ec411dec9dULL },
 170     { "abcdefghijklm",                    0xe8a865539f4eadfeULL },
 171     { "abcdefghijklmnopqrstu",            0x261cdf85faaf4e79ULL },
 172     { "abcdefghijklmnopqrstuvwxyzabcdef", 0x43ba70e4198e3b2aULL },
 173     { "abcdefghijklmnopqrstuvwxyzabcdef"
 174       "abcdefghijklmnopqrstuvwxyzghijkl"
 175       "abcdefghijklmnopqrstuvwxyzmnopqr"
 176       "abcdefghijklmnopqrstuvwxyzstuvwx"
 177       "abcdefghijklmnopqrstuvwxyzyzabcd", 0xdcd57fb2afdf72beULL },
 178     { "a",                                0xaeb6f9d5517c61f8ULL },
 179     { "aa",                               0xf2b3b69a9736a1ebULL },
 180     { "aaa",                              0xf752eb6f07b1cafeULL },
 181     { "aaaaa",                            0x812bd21e1236954cULL },
 182     { "aaaaaaaa",                         0xff07a2cff08ac587ULL },
 183     { "aaaaaaaaaaaaa",                    0x84ac949d54d704ecULL },
 184     { "aaaaaaaaaaaaaaaaaaaaa",            0xcb2c8fb6be8f5648ULL },
 185     { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0xcc40ab7f164091b6ULL },
 186     { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 187       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 188       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 189       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 190       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0xc58e174c1e78ffe9ULL },
 191     { "z",                                0x1ba160d7e8f8785cULL },
 192     { "zz",                               0x2c5c03172f1285d7ULL },
 193     { "zzz",                              0x9d2c4f4b507a2ac3ULL },
 194     { "zzzzz",                            0x0f03b9031735693aULL },
 195     { "zzzzzzzz",                         0xe674147c8582c08eULL },
 196     { "zzzzzzzzzzzzz",                    0x3162d9fa6938db83ULL },
 197     { "zzzzzzzzzzzzzzzzzzzzz",            0x37b9a549e013620cULL },
 198     { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0x8921470aff885016ULL },
 199     { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 200       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 201       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 202       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 203       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0xf60fdcd9beb08441ULL },
 204     { "a",                                0xaeb6f9d5517c61f8ULL },
 205     { "ab",                               0x7ab1edb96be496b4ULL },
 206     { "aba",                              0x3edb049950884d0aULL },
 207     { "ababa",                            0x8f2de9e73a97714bULL },
 208     { "abababab",                         0xee14a29ddf0ce54cULL },
 209     { "ababababababa",                    0x38b3ddaada2d52b4ULL },
 210     { "ababababababababababa",            0xd3665364219f2b85ULL },
 211     { "abababababababababababababababab"
 212       "abababababababababababababababab"
 213       "abababababababababababababababab"
 214       "abababababababababababababababab"
 215       "abababababababababababababababab", 0x840192d129f7a22bULL }
 216 #elif SIZE_MAX == UINT32_MAX
 217  { "a",                                0x000000004605f745ULL },
 218  { "ab",                               0x00000000d5f06301ULL },
 219  { "abc",                              0x00000000559fe1eeULL },
 220  { "abcde",                            0x00000000424028d7ULL },
 221  { "abcdefgh",                         0x000000007bb119f8ULL },
 222  { "abcdefghijklm",                    0x00000000edbca513ULL },
 223  { "abcdefghijklmnopqrstu",            0x000000007c15712eULL },
 224  { "abcdefghijklmnopqrstuvwxyzabcdef", 0x000000000b3aad66ULL },
 225  { "abcdefghijklmnopqrstuvwxyzabcdef"
 226    "abcdefghijklmnopqrstuvwxyzghijkl"
 227    "abcdefghijklmnopqrstuvwxyzmnopqr"
 228    "abcdefghijklmnopqrstuvwxyzstuvwx"
 229    "abcdefghijklmnopqrstuvwxyzyzabcd", 0x000000008c758c8bULL },
 230  { "a",                                0x000000004605f745ULL },
 231  { "aa",                               0x00000000dc0a52daULL },
 232  { "aaa",                              0x00000000b309274fULL },
 233  { "aaaaa",                            0x00000000203b5ef6ULL },
 234  { "aaaaaaaa",                         0x00000000a429e18fULL },
 235  { "aaaaaaaaaaaaa",                    0x000000008662070bULL },
 236  { "aaaaaaaaaaaaaaaaaaaaa",            0x000000003f11151cULL },
 237  { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0x000000008600fe20ULL },
 238  { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 239    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 240    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 241    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 242    "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0x000000004e0e0804ULL },
 243  { "z",                                0x00000000c5e405e9ULL },
 244  { "zz",                               0x00000000a8d8a2c6ULL },
 245  { "zzz",                              0x00000000fc2af672ULL },
 246  { "zzzzz",                            0x0000000047d9efe6ULL },
 247  { "zzzzzzzz",                         0x0000000080d77794ULL },
 248  { "zzzzzzzzzzzzz",                    0x00000000405f93adULL },
 249  { "zzzzzzzzzzzzzzzzzzzzz",            0x00000000fc72838dULL },
 250  { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0x000000007ce160f1ULL },
 251  { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 252    "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 253    "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 254    "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 255    "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0x00000000aed9ed1bULL },
 256  { "a",                                0x000000004605f745ULL },
 257  { "ab",                               0x00000000d5f06301ULL },
 258  { "aba",                              0x00000000a85cd91bULL },
 259  { "ababa",                            0x000000009e3bb52eULL },
 260  { "abababab",                         0x000000002709b3b9ULL },
 261  { "ababababababa",                    0x000000003a234174ULL },
 262  { "ababababababababababa",            0x000000005c63e5ceULL },
 263  { "abababababababababababababababab", 0x0000000013f74334ULL },
 264  { "abababababababababababababababab"
 265    "abababababababababababababababab"
 266    "abababababababababababababababab"
 267    "abababababababababababababababab"
 268    "abababababababababababababababab", 0x00000000c1a6f135ULL },
 269 #else
 270 #error This test only supports 64-bit and 32-bit systems.
 271 #endif
 272   };
 273   for (unsigned i = 0; i < sizeof(golden_data)/sizeof(*golden_data); ++i) {
 274     StringRef str = golden_data[i].s;
 275     hash_code hash = hash_combine_range(str.begin(), str.end());
 276 #if 0 // Enable this to generate paste-able text for the above structure.
 277     std::string member_str = "\"" + str.str() + "\",";
 278     fprintf(stderr, " { %-35s 0x%016llxULL },\n",
 279             member_str.c_str(), static_cast<uint64_t>(hash));
 280 #endif
 281     EXPECT_EQ(static_cast<size_t>(golden_data[i].hash),
 282               static_cast<size_t>(hash));
 283   }
 284 }
 285
 286 TEST(HashingTest, HashCombineBasicTest) {
 287   // Hashing a sequence of homogenous types matches range hashing.
 288   const int i1 = 42, i2 = 43, i3 = 123, i4 = 999, i5 = 0, i6 = 79;
 289   const int arr1[] = { i1, i2, i3, i4, i5, i6 };
 290   EXPECT_EQ(hash_combine_range(arr1, arr1 + 1), hash_combine(i1));
 291   EXPECT_EQ(hash_combine_range(arr1, arr1 + 2), hash_combine(i1, i2));
 292   EXPECT_EQ(hash_combine_range(arr1, arr1 + 3), hash_combine(i1, i2, i3));
 293   EXPECT_EQ(hash_combine_range(arr1, arr1 + 4), hash_combine(i1, i2, i3, i4));
 294   EXPECT_EQ(hash_combine_range(arr1, arr1 + 5),
 295             hash_combine(i1, i2, i3, i4, i5));
 296   EXPECT_EQ(hash_combine_range(arr1, arr1 + 6),
 297             hash_combine(i1, i2, i3, i4, i5, i6));
 298
 299   // Hashing a sequence of heterogenous types which *happen* to all produce the
 300   // same data for hashing produces the same as a range-based hash of the
 301   // fundamental values.
 302   const size_t s1 = 1024, s2 = 8888, s3 = 9000000;
 303   const HashableDummy d1 = { 1024 }, d2 = { 8888 }, d3 = { 9000000 };
 304   const size_t arr2[] = { s1, s2, s3 };
 305   EXPECT_EQ(hash_combine_range(begin(arr2), end(arr2)),
 306             hash_combine(s1, s2, s3));
 307   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(s1, s2, d3));
 308   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(s1, d2, s3));
 309   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, s2, s3));
 310   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, d2, s3));
 311   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, d2, d3));
 312
 313   // Permuting values causes hashes to change.
 314   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i1, i1, i2));
 315   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i1, i2, i1));
 316   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i1, i1));
 317   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i2, i1));
 318   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i2, i2));
 319   EXPECT_NE(hash_combine(i2, i1, i1), hash_combine(i1, i1, i2));
 320   EXPECT_NE(hash_combine(i1, i1, i2), hash_combine(i1, i2, i1));
 321   EXPECT_NE(hash_combine(i1, i2, i1), hash_combine(i2, i1, i1));
 322
 323   // Changing type w/o changing value causes hashes to change.
 324   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine((char)i1, i2, i3));
 325   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine(i1, (char)i2, i3));
 326   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine(i1, i2, (char)i3));
 327
 328   // This is array of uint64, but it should have the exact same byte pattern as
 329   // an array of LargeTestIntegers.
 330   const uint64_t bigarr[] = {
 331     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 332     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 333     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 334     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 335     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 336     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 337     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 338     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 339     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL
 340   };
 341   // Hash a preposterously large integer, both aligned with the buffer and
 342   // misaligned.
 343   const LargeTestInteger li = { {
 344     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 345     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 346     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL
 347   } };
 348   // Rotate the storage from 'li'.
 349   const LargeTestInteger l2 = { {
 350     0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL, 0xdeadbeafdeadbeefULL,
 351     0xfefefefededededeULL, 0xafafafafededededULL, 0xffffeeeeddddccccULL,
 352     0xaaaacbcbffffababULL, 0xaaaaaaaaababababULL
 353   } };
 354   const LargeTestInteger l3 = { {
 355     0xccddeeffeeddccbbULL, 0xdeadbeafdeadbeefULL, 0xfefefefededededeULL,
 356     0xafafafafededededULL, 0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 357     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL
 358   } };
 359   EXPECT_EQ(hash_combine_range(begin(bigarr), end(bigarr)),
 360             hash_combine(li, li, li));
 361   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 9),
 362             hash_combine(bigarr[0], l2));
 363   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 10),
 364             hash_combine(bigarr[0], bigarr[1], l3));
 365   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 17),
 366             hash_combine(li, bigarr[0], l2));
 367   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 18),
 368             hash_combine(li, bigarr[0], bigarr[1], l3));
 369   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 18),
 370             hash_combine(bigarr[0], l2, bigarr[9], l3));
 371   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 20),
 372             hash_combine(bigarr[0], l2, bigarr[9], l3, bigarr[18], bigarr[19]));
 373 }
 374
 375 }