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 struct NonPOD {
  34   uint64_t x, y;
  35   NonPOD(uint64_t x, uint64_t y) : x(x), y(y) {}
  36   ~NonPOD() {}
  37   friend hash_code hash_value(const NonPOD &obj) {
  38     return hash_combine(obj.x, obj.y);
  39   }
  40 };
  41
  42 namespace hashing {
  43 namespace detail {
  44 template <> struct is_hashable_data<LargeTestInteger> : std::true_type {};
  45 } // namespace detail
  46 } // namespace hashing
  47
  48 } // namespace llvm
  49
  50 using namespace llvm;
  51
  52 namespace {
  53
  54 enum TestEnumeration {
  55   TE_Foo = 42,
  56   TE_Bar = 43
  57 };
  58
  59 TEST(HashingTest, HashValueBasicTest) {
  60   int x = 42, y = 43, c = 'x';
  61   void *p = 0;
  62   uint64_t i = 71;
  63   const unsigned ci = 71;
  64   volatile int vi = 71;
  65   const volatile int cvi = 71;
  66   uintptr_t addr = reinterpret_cast<uintptr_t>(&y);
  67   EXPECT_EQ(hash_value(42), hash_value(x));
  68   EXPECT_EQ(hash_value(42), hash_value(TE_Foo));
  69   EXPECT_NE(hash_value(42), hash_value(y));
  70   EXPECT_NE(hash_value(42), hash_value(TE_Bar));
  71   EXPECT_NE(hash_value(42), hash_value(p));
  72   EXPECT_EQ(hash_value(71), hash_value(i));
  73   EXPECT_EQ(hash_value(71), hash_value(ci));
  74   EXPECT_EQ(hash_value(71), hash_value(vi));
  75   EXPECT_EQ(hash_value(71), hash_value(cvi));
  76   EXPECT_EQ(hash_value(c), hash_value('x'));
  77   EXPECT_EQ(hash_value('4'), hash_value('0' + 4));
  78   EXPECT_EQ(hash_value(addr), hash_value(&y));
  79 }
  80
  81 TEST(HashingTest, HashValueStdPair) {
  82   EXPECT_EQ(hash_combine(42, 43), hash_value(std::make_pair(42, 43)));
  83   EXPECT_NE(hash_combine(43, 42), hash_value(std::make_pair(42, 43)));
  84   EXPECT_NE(hash_combine(42, 43), hash_value(std::make_pair(42ull, 43ull)));
  85   EXPECT_NE(hash_combine(42, 43), hash_value(std::make_pair(42, 43ull)));
  86   EXPECT_NE(hash_combine(42, 43), hash_value(std::make_pair(42ull, 43)));
  87
  88   // Note that pairs are implicitly flattened to a direct sequence of data and
  89   // hashed efficiently as a consequence.
  90   EXPECT_EQ(hash_combine(42, 43, 44),
  91             hash_value(std::make_pair(42, std::make_pair(43, 44))));
  92   EXPECT_EQ(hash_value(std::make_pair(42, std::make_pair(43, 44))),
  93             hash_value(std::make_pair(std::make_pair(42, 43), 44)));
  94
  95   // Ensure that pairs which have padding bytes *inside* them don't get treated
  96   // this way.
  97   EXPECT_EQ(hash_combine('0', hash_combine(1ull, '2')),
  98             hash_value(std::make_pair('0', std::make_pair(1ull, '2'))));
  99
 100   // Ensure that non-POD pairs don't explode the traits used.
 101   NonPOD obj1(1, 2), obj2(3, 4), obj3(5, 6);
 102   EXPECT_EQ(hash_combine(obj1, hash_combine(obj2, obj3)),
 103             hash_value(std::make_pair(obj1, std::make_pair(obj2, obj3))));
 104 }
 105
 106 TEST(HashingTest, HashValueStdString) {
 107   std::string s = "Hello World!";
 108   EXPECT_EQ(hash_combine_range(s.c_str(), s.c_str() + s.size()), hash_value(s));
 109   EXPECT_EQ(hash_combine_range(s.c_str(), s.c_str() + s.size() - 1),
 110             hash_value(s.substr(0, s.size() - 1)));
 111   EXPECT_EQ(hash_combine_range(s.c_str() + 1, s.c_str() + s.size() - 1),
 112             hash_value(s.substr(1, s.size() - 2)));
 113
 114   std::wstring ws = L"Hello Wide World!";
 115   EXPECT_EQ(hash_combine_range(ws.c_str(), ws.c_str() + ws.size()),
 116             hash_value(ws));
 117   EXPECT_EQ(hash_combine_range(ws.c_str(), ws.c_str() + ws.size() - 1),
 118             hash_value(ws.substr(0, ws.size() - 1)));
 119   EXPECT_EQ(hash_combine_range(ws.c_str() + 1, ws.c_str() + ws.size() - 1),
 120             hash_value(ws.substr(1, ws.size() - 2)));
 121 }
 122
 123 template <typename T, size_t N> T *begin(T (&arr)[N]) { return arr; }
 124 template <typename T, size_t N> T *end(T (&arr)[N]) { return arr + N; }
 125
 126 // Provide a dummy, hashable type designed for easy verification: its hash is
 127 // the same as its value.
 128 struct HashableDummy { size_t value; };
 129 hash_code hash_value(HashableDummy dummy) { return dummy.value; }
 130
 131 TEST(HashingTest, HashCombineRangeBasicTest) {
 132   // Leave this uninitialized in the hope that valgrind will catch bad reads.
 133   int dummy;
 134   hash_code dummy_hash = hash_combine_range(&dummy, &dummy);
 135   EXPECT_NE(hash_code(0), dummy_hash);
 136
 137   const int arr1[] = { 1, 2, 3 };
 138   hash_code arr1_hash = hash_combine_range(begin(arr1), end(arr1));
 139   EXPECT_NE(dummy_hash, arr1_hash);
 140   EXPECT_EQ(arr1_hash, hash_combine_range(begin(arr1), end(arr1)));
 141
 142   const std::vector<int> vec(begin(arr1), end(arr1));
 143   EXPECT_EQ(arr1_hash, hash_combine_range(vec.begin(), vec.end()));
 144
 145   const std::list<int> list(begin(arr1), end(arr1));
 146   EXPECT_EQ(arr1_hash, hash_combine_range(list.begin(), list.end()));
 147
 148   const std::deque<int> deque(begin(arr1), end(arr1));
 149   EXPECT_EQ(arr1_hash, hash_combine_range(deque.begin(), deque.end()));
 150
 151   const int arr2[] = { 3, 2, 1 };
 152   hash_code arr2_hash = hash_combine_range(begin(arr2), end(arr2));
 153   EXPECT_NE(dummy_hash, arr2_hash);
 154   EXPECT_NE(arr1_hash, arr2_hash);
 155
 156   const int arr3[] = { 1, 1, 2, 3 };
 157   hash_code arr3_hash = hash_combine_range(begin(arr3), end(arr3));
 158   EXPECT_NE(dummy_hash, arr3_hash);
 159   EXPECT_NE(arr1_hash, arr3_hash);
 160
 161   const int arr4[] = { 1, 2, 3, 3 };
 162   hash_code arr4_hash = hash_combine_range(begin(arr4), end(arr4));
 163   EXPECT_NE(dummy_hash, arr4_hash);
 164   EXPECT_NE(arr1_hash, arr4_hash);
 165
 166   const size_t arr5[] = { 1, 2, 3 };
 167   const HashableDummy d_arr5[] = { {1}, {2}, {3} };
 168   hash_code arr5_hash = hash_combine_range(begin(arr5), end(arr5));
 169   hash_code d_arr5_hash = hash_combine_range(begin(d_arr5), end(d_arr5));
 170   EXPECT_EQ(arr5_hash, d_arr5_hash);
 171 }
 172
 173 TEST(HashingTest, HashCombineRangeLengthDiff) {
 174   // Test that as only the length varies, we compute different hash codes for
 175   // sequences.
 176   std::map<size_t, size_t> code_to_size;
 177   std::vector<char> all_one_c(256, '\xff');
 178   for (unsigned Idx = 1, Size = all_one_c.size(); Idx < Size; ++Idx) {
 179     hash_code code = hash_combine_range(&all_one_c[0], &all_one_c[0] + Idx);
 180     std::map<size_t, size_t>::iterator
 181       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 182     EXPECT_EQ(Idx, I->second);
 183   }
 184   code_to_size.clear();
 185   std::vector<char> all_zero_c(256, '\0');
 186   for (unsigned Idx = 1, Size = all_zero_c.size(); Idx < Size; ++Idx) {
 187     hash_code code = hash_combine_range(&all_zero_c[0], &all_zero_c[0] + Idx);
 188     std::map<size_t, size_t>::iterator
 189       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 190     EXPECT_EQ(Idx, I->second);
 191   }
 192   code_to_size.clear();
 193   std::vector<unsigned> all_one_int(512, -1);
 194   for (unsigned Idx = 1, Size = all_one_int.size(); Idx < Size; ++Idx) {
 195     hash_code code = hash_combine_range(&all_one_int[0], &all_one_int[0] + Idx);
 196     std::map<size_t, size_t>::iterator
 197       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 198     EXPECT_EQ(Idx, I->second);
 199   }
 200   code_to_size.clear();
 201   std::vector<unsigned> all_zero_int(512, 0);
 202   for (unsigned Idx = 1, Size = all_zero_int.size(); Idx < Size; ++Idx) {
 203     hash_code code = hash_combine_range(&all_zero_int[0], &all_zero_int[0] + Idx);
 204     std::map<size_t, size_t>::iterator
 205       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 206     EXPECT_EQ(Idx, I->second);
 207   }
 208 }
 209
 210 TEST(HashingTest, HashCombineRangeGoldenTest) {
 211   struct { const char *s; uint64_t hash; } golden_data[] = {
 212 #if SIZE_MAX == UINT64_MAX
 213     { "a",                                0xaeb6f9d5517c61f8ULL },
 214     { "ab",                               0x7ab1edb96be496b4ULL },
 215     { "abc",                              0xe38e60bf19c71a3fULL },
 216     { "abcde",                            0xd24461a66de97f6eULL },
 217     { "abcdefgh",                         0x4ef872ec411dec9dULL },
 218     { "abcdefghijklm",                    0xe8a865539f4eadfeULL },
 219     { "abcdefghijklmnopqrstu",            0x261cdf85faaf4e79ULL },
 220     { "abcdefghijklmnopqrstuvwxyzabcdef", 0x43ba70e4198e3b2aULL },
 221     { "abcdefghijklmnopqrstuvwxyzabcdef"
 222       "abcdefghijklmnopqrstuvwxyzghijkl"
 223       "abcdefghijklmnopqrstuvwxyzmnopqr"
 224       "abcdefghijklmnopqrstuvwxyzstuvwx"
 225       "abcdefghijklmnopqrstuvwxyzyzabcd", 0xdcd57fb2afdf72beULL },
 226     { "a",                                0xaeb6f9d5517c61f8ULL },
 227     { "aa",                               0xf2b3b69a9736a1ebULL },
 228     { "aaa",                              0xf752eb6f07b1cafeULL },
 229     { "aaaaa",                            0x812bd21e1236954cULL },
 230     { "aaaaaaaa",                         0xff07a2cff08ac587ULL },
 231     { "aaaaaaaaaaaaa",                    0x84ac949d54d704ecULL },
 232     { "aaaaaaaaaaaaaaaaaaaaa",            0xcb2c8fb6be8f5648ULL },
 233     { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0xcc40ab7f164091b6ULL },
 234     { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 235       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 236       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 237       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 238       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0xc58e174c1e78ffe9ULL },
 239     { "z",                                0x1ba160d7e8f8785cULL },
 240     { "zz",                               0x2c5c03172f1285d7ULL },
 241     { "zzz",                              0x9d2c4f4b507a2ac3ULL },
 242     { "zzzzz",                            0x0f03b9031735693aULL },
 243     { "zzzzzzzz",                         0xe674147c8582c08eULL },
 244     { "zzzzzzzzzzzzz",                    0x3162d9fa6938db83ULL },
 245     { "zzzzzzzzzzzzzzzzzzzzz",            0x37b9a549e013620cULL },
 246     { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0x8921470aff885016ULL },
 247     { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 248       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 249       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 250       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 251       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0xf60fdcd9beb08441ULL },
 252     { "a",                                0xaeb6f9d5517c61f8ULL },
 253     { "ab",                               0x7ab1edb96be496b4ULL },
 254     { "aba",                              0x3edb049950884d0aULL },
 255     { "ababa",                            0x8f2de9e73a97714bULL },
 256     { "abababab",                         0xee14a29ddf0ce54cULL },
 257     { "ababababababa",                    0x38b3ddaada2d52b4ULL },
 258     { "ababababababababababa",            0xd3665364219f2b85ULL },
 259     { "abababababababababababababababab", 0xa75cd6afbf1bc972ULL },
 260     { "abababababababababababababababab"
 261       "abababababababababababababababab"
 262       "abababababababababababababababab"
 263       "abababababababababababababababab"
 264       "abababababababababababababababab", 0x840192d129f7a22bULL }
 265 #elif SIZE_MAX == UINT32_MAX
 266     { "a",                                0x000000004605f745ULL },
 267     { "ab",                               0x00000000d5f06301ULL },
 268     { "abc",                              0x00000000559fe1eeULL },
 269     { "abcde",                            0x00000000424028d7ULL },
 270     { "abcdefgh",                         0x000000007bb119f8ULL },
 271     { "abcdefghijklm",                    0x00000000edbca513ULL },
 272     { "abcdefghijklmnopqrstu",            0x000000007c15712eULL },
 273     { "abcdefghijklmnopqrstuvwxyzabcdef", 0x000000000b3aad66ULL },
 274     { "abcdefghijklmnopqrstuvwxyzabcdef"
 275       "abcdefghijklmnopqrstuvwxyzghijkl"
 276       "abcdefghijklmnopqrstuvwxyzmnopqr"
 277       "abcdefghijklmnopqrstuvwxyzstuvwx"
 278       "abcdefghijklmnopqrstuvwxyzyzabcd", 0x000000008c758c8bULL },
 279     { "a",                                0x000000004605f745ULL },
 280     { "aa",                               0x00000000dc0a52daULL },
 281     { "aaa",                              0x00000000b309274fULL },
 282     { "aaaaa",                            0x00000000203b5ef6ULL },
 283     { "aaaaaaaa",                         0x00000000a429e18fULL },
 284     { "aaaaaaaaaaaaa",                    0x000000008662070bULL },
 285     { "aaaaaaaaaaaaaaaaaaaaa",            0x000000003f11151cULL },
 286     { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0x000000008600fe20ULL },
 287     { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 288       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 289       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 290       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 291       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0x000000004e0e0804ULL },
 292     { "z",                                0x00000000c5e405e9ULL },
 293     { "zz",                               0x00000000a8d8a2c6ULL },
 294     { "zzz",                              0x00000000fc2af672ULL },
 295     { "zzzzz",                            0x0000000047d9efe6ULL },
 296     { "zzzzzzzz",                         0x0000000080d77794ULL },
 297     { "zzzzzzzzzzzzz",                    0x00000000405f93adULL },
 298     { "zzzzzzzzzzzzzzzzzzzzz",            0x00000000fc72838dULL },
 299     { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0x000000007ce160f1ULL },
 300     { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 301       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 302       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 303       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 304       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0x00000000aed9ed1bULL },
 305     { "a",                                0x000000004605f745ULL },
 306     { "ab",                               0x00000000d5f06301ULL },
 307     { "aba",                              0x00000000a85cd91bULL },
 308     { "ababa",                            0x000000009e3bb52eULL },
 309     { "abababab",                         0x000000002709b3b9ULL },
 310     { "ababababababa",                    0x000000003a234174ULL },
 311     { "ababababababababababa",            0x000000005c63e5ceULL },
 312     { "abababababababababababababababab", 0x0000000013f74334ULL },
 313     { "abababababababababababababababab"
 314       "abababababababababababababababab"
 315       "abababababababababababababababab"
 316       "abababababababababababababababab"
 317       "abababababababababababababababab", 0x00000000c1a6f135ULL },
 318 #else
 319 #error This test only supports 64-bit and 32-bit systems.
 320 #endif
 321   };
 322   for (unsigned i = 0; i < sizeof(golden_data)/sizeof(*golden_data); ++i) {
 323     StringRef str = golden_data[i].s;
 324     hash_code hash = hash_combine_range(str.begin(), str.end());
 325 #if 0 // Enable this to generate paste-able text for the above structure.
 326     std::string member_str = "\"" + str.str() + "\",";
 327     fprintf(stderr, " { %-35s 0x%016llxULL },\n",
 328             member_str.c_str(), static_cast<uint64_t>(hash));
 329 #endif
 330     EXPECT_EQ(static_cast<size_t>(golden_data[i].hash),
 331               static_cast<size_t>(hash));
 332   }
 333 }
 334
 335 TEST(HashingTest, HashCombineBasicTest) {
 336   // Hashing a sequence of homogenous types matches range hashing.
 337   const int i1 = 42, i2 = 43, i3 = 123, i4 = 999, i5 = 0, i6 = 79;
 338   const int arr1[] = { i1, i2, i3, i4, i5, i6 };
 339   EXPECT_EQ(hash_combine_range(arr1, arr1 + 1), hash_combine(i1));
 340   EXPECT_EQ(hash_combine_range(arr1, arr1 + 2), hash_combine(i1, i2));
 341   EXPECT_EQ(hash_combine_range(arr1, arr1 + 3), hash_combine(i1, i2, i3));
 342   EXPECT_EQ(hash_combine_range(arr1, arr1 + 4), hash_combine(i1, i2, i3, i4));
 343   EXPECT_EQ(hash_combine_range(arr1, arr1 + 5),
 344             hash_combine(i1, i2, i3, i4, i5));
 345   EXPECT_EQ(hash_combine_range(arr1, arr1 + 6),
 346             hash_combine(i1, i2, i3, i4, i5, i6));
 347
 348   // Hashing a sequence of heterogeneous types which *happen* to all produce the
 349   // same data for hashing produces the same as a range-based hash of the
 350   // fundamental values.
 351   const size_t s1 = 1024, s2 = 8888, s3 = 9000000;
 352   const HashableDummy d1 = { 1024 }, d2 = { 8888 }, d3 = { 9000000 };
 353   const size_t arr2[] = { s1, s2, s3 };
 354   EXPECT_EQ(hash_combine_range(begin(arr2), end(arr2)),
 355             hash_combine(s1, s2, s3));
 356   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(s1, s2, d3));
 357   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(s1, d2, s3));
 358   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, s2, s3));
 359   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, d2, s3));
 360   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, d2, d3));
 361
 362   // Permuting values causes hashes to change.
 363   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i1, i1, i2));
 364   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i1, i2, i1));
 365   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i1, i1));
 366   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i2, i1));
 367   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i2, i2));
 368   EXPECT_NE(hash_combine(i2, i1, i1), hash_combine(i1, i1, i2));
 369   EXPECT_NE(hash_combine(i1, i1, i2), hash_combine(i1, i2, i1));
 370   EXPECT_NE(hash_combine(i1, i2, i1), hash_combine(i2, i1, i1));
 371
 372   // Changing type w/o changing value causes hashes to change.
 373   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine((char)i1, i2, i3));
 374   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine(i1, (char)i2, i3));
 375   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine(i1, i2, (char)i3));
 376
 377   // This is array of uint64, but it should have the exact same byte pattern as
 378   // an array of LargeTestIntegers.
 379   const uint64_t bigarr[] = {
 380     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 381     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 382     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 383     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 384     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 385     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 386     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 387     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 388     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL
 389   };
 390   // Hash a preposterously large integer, both aligned with the buffer and
 391   // misaligned.
 392   const LargeTestInteger li = { {
 393     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 394     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 395     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL
 396   } };
 397   // Rotate the storage from 'li'.
 398   const LargeTestInteger l2 = { {
 399     0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL, 0xdeadbeafdeadbeefULL,
 400     0xfefefefededededeULL, 0xafafafafededededULL, 0xffffeeeeddddccccULL,
 401     0xaaaacbcbffffababULL, 0xaaaaaaaaababababULL
 402   } };
 403   const LargeTestInteger l3 = { {
 404     0xccddeeffeeddccbbULL, 0xdeadbeafdeadbeefULL, 0xfefefefededededeULL,
 405     0xafafafafededededULL, 0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 406     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL
 407   } };
 408   EXPECT_EQ(hash_combine_range(begin(bigarr), end(bigarr)),
 409             hash_combine(li, li, li));
 410   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 9),
 411             hash_combine(bigarr[0], l2));
 412   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 10),
 413             hash_combine(bigarr[0], bigarr[1], l3));
 414   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 17),
 415             hash_combine(li, bigarr[0], l2));
 416   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 18),
 417             hash_combine(li, bigarr[0], bigarr[1], l3));
 418   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 18),
 419             hash_combine(bigarr[0], l2, bigarr[9], l3));
 420   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 20),
 421             hash_combine(bigarr[0], l2, bigarr[9], l3, bigarr[18], bigarr[19]));
 422 }
 423
 424 }