unittests/ADT/HashingTest.cpp

   1 //===- llvm/unittest/ADT/HashingTest.cpp ----------------------------------===//
   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 // Hashing.h unit tests.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/ADT/Hashing.h"
  14 #include "llvm/Support/DataTypes.h"
  15 #include "gtest/gtest.h"
  16 #include <deque>
  17 #include <list>
  18 #include <map>
  19 #include <vector>
  20
  21 namespace llvm {
  22
  23 // Helper for test code to print hash codes.
  24 void PrintTo(const hash_code &code, std::ostream *os) {
  25   *os << static_cast<size_t>(code);
  26 }
  27
  28 // Fake an object that is recognized as hashable data to test super large
  29 // objects.
  30 struct LargeTestInteger { uint64_t arr[8]; };
  31
  32 struct NonPOD {
  33   uint64_t x, y;
  34   NonPOD(uint64_t x, uint64_t y) : x(x), y(y) {}
  35   friend hash_code hash_value(const NonPOD &obj) {
  36     return hash_combine(obj.x, obj.y);
  37   }
  38 };
  39
  40 namespace hashing {
  41 namespace detail {
  42 template <> struct is_hashable_data<LargeTestInteger> : std::true_type {};
  43 } // namespace detail
  44 } // namespace hashing
  45
  46 } // namespace llvm
  47
  48 using namespace llvm;
  49
  50 namespace {
  51
  52 enum TestEnumeration {
  53   TE_Foo = 42,
  54   TE_Bar = 43
  55 };
  56
  57 TEST(HashingTest, HashValueBasicTest) {
  58   int x = 42, y = 43, c = 'x';
  59   void *p = nullptr;
  60   uint64_t i = 71;
  61   const unsigned ci = 71;
  62   volatile int vi = 71;
  63   const volatile int cvi = 71;
  64   uintptr_t addr = reinterpret_cast<uintptr_t>(&y);
  65   EXPECT_EQ(hash_value(42), hash_value(x));
  66   EXPECT_EQ(hash_value(42), hash_value(TE_Foo));
  67   EXPECT_NE(hash_value(42), hash_value(y));
  68   EXPECT_NE(hash_value(42), hash_value(TE_Bar));
  69   EXPECT_NE(hash_value(42), hash_value(p));
  70   EXPECT_EQ(hash_value(71), hash_value(i));
  71   EXPECT_EQ(hash_value(71), hash_value(ci));
  72   EXPECT_EQ(hash_value(71), hash_value(vi));
  73   EXPECT_EQ(hash_value(71), hash_value(cvi));
  74   EXPECT_EQ(hash_value(c), hash_value('x'));
  75   EXPECT_EQ(hash_value('4'), hash_value('0' + 4));
  76   EXPECT_EQ(hash_value(addr), hash_value(&y));
  77 }
  78
  79 TEST(HashingTest, HashValueStdPair) {
  80   EXPECT_EQ(hash_combine(42, 43), hash_value(std::make_pair(42, 43)));
  81   EXPECT_NE(hash_combine(43, 42), hash_value(std::make_pair(42, 43)));
  82   EXPECT_NE(hash_combine(42, 43), hash_value(std::make_pair(42ull, 43ull)));
  83   EXPECT_NE(hash_combine(42, 43), hash_value(std::make_pair(42, 43ull)));
  84   EXPECT_NE(hash_combine(42, 43), hash_value(std::make_pair(42ull, 43)));
  85
  86   // Note that pairs are implicitly flattened to a direct sequence of data and
  87   // hashed efficiently as a consequence.
  88   EXPECT_EQ(hash_combine(42, 43, 44),
  89             hash_value(std::make_pair(42, std::make_pair(43, 44))));
  90   EXPECT_EQ(hash_value(std::make_pair(42, std::make_pair(43, 44))),
  91             hash_value(std::make_pair(std::make_pair(42, 43), 44)));
  92
  93   // Ensure that pairs which have padding bytes *inside* them don't get treated
  94   // this way.
  95   EXPECT_EQ(hash_combine('0', hash_combine(1ull, '2')),
  96             hash_value(std::make_pair('0', std::make_pair(1ull, '2'))));
  97
  98   // Ensure that non-POD pairs don't explode the traits used.
  99   NonPOD obj1(1, 2), obj2(3, 4), obj3(5, 6);
 100   EXPECT_EQ(hash_combine(obj1, hash_combine(obj2, obj3)),
 101             hash_value(std::make_pair(obj1, std::make_pair(obj2, obj3))));
 102 }
 103
 104 TEST(HashingTest, HashValueStdString) {
 105   std::string s = "Hello World!";
 106   EXPECT_EQ(hash_combine_range(s.c_str(), s.c_str() + s.size()), hash_value(s));
 107   EXPECT_EQ(hash_combine_range(s.c_str(), s.c_str() + s.size() - 1),
 108             hash_value(s.substr(0, s.size() - 1)));
 109   EXPECT_EQ(hash_combine_range(s.c_str() + 1, s.c_str() + s.size() - 1),
 110             hash_value(s.substr(1, s.size() - 2)));
 111
 112   std::wstring ws = L"Hello Wide World!";
 113   EXPECT_EQ(hash_combine_range(ws.c_str(), ws.c_str() + ws.size()),
 114             hash_value(ws));
 115   EXPECT_EQ(hash_combine_range(ws.c_str(), ws.c_str() + ws.size() - 1),
 116             hash_value(ws.substr(0, ws.size() - 1)));
 117   EXPECT_EQ(hash_combine_range(ws.c_str() + 1, ws.c_str() + ws.size() - 1),
 118             hash_value(ws.substr(1, ws.size() - 2)));
 119 }
 120
 121 template <typename T, size_t N> T *begin(T (&arr)[N]) { return arr; }
 122 template <typename T, size_t N> T *end(T (&arr)[N]) { return arr + N; }
 123
 124 // Provide a dummy, hashable type designed for easy verification: its hash is
 125 // the same as its value.
 126 struct HashableDummy { size_t value; };
 127 hash_code hash_value(HashableDummy dummy) { return dummy.value; }
 128
 129 TEST(HashingTest, HashCombineRangeBasicTest) {
 130   // Leave this uninitialized in the hope that valgrind will catch bad reads.
 131   int dummy;
 132   hash_code dummy_hash = hash_combine_range(&dummy, &dummy);
 133   EXPECT_NE(hash_code(0), dummy_hash);
 134
 135   const int arr1[] = { 1, 2, 3 };
 136   hash_code arr1_hash = hash_combine_range(begin(arr1), end(arr1));
 137   EXPECT_NE(dummy_hash, arr1_hash);
 138   EXPECT_EQ(arr1_hash, hash_combine_range(begin(arr1), end(arr1)));
 139
 140   const std::vector<int> vec(begin(arr1), end(arr1));
 141   EXPECT_EQ(arr1_hash, hash_combine_range(vec.begin(), vec.end()));
 142
 143   const std::list<int> list(begin(arr1), end(arr1));
 144   EXPECT_EQ(arr1_hash, hash_combine_range(list.begin(), list.end()));
 145
 146   const std::deque<int> deque(begin(arr1), end(arr1));
 147   EXPECT_EQ(arr1_hash, hash_combine_range(deque.begin(), deque.end()));
 148
 149   const int arr2[] = { 3, 2, 1 };
 150   hash_code arr2_hash = hash_combine_range(begin(arr2), end(arr2));
 151   EXPECT_NE(dummy_hash, arr2_hash);
 152   EXPECT_NE(arr1_hash, arr2_hash);
 153
 154   const int arr3[] = { 1, 1, 2, 3 };
 155   hash_code arr3_hash = hash_combine_range(begin(arr3), end(arr3));
 156   EXPECT_NE(dummy_hash, arr3_hash);
 157   EXPECT_NE(arr1_hash, arr3_hash);
 158
 159   const int arr4[] = { 1, 2, 3, 3 };
 160   hash_code arr4_hash = hash_combine_range(begin(arr4), end(arr4));
 161   EXPECT_NE(dummy_hash, arr4_hash);
 162   EXPECT_NE(arr1_hash, arr4_hash);
 163
 164   const size_t arr5[] = { 1, 2, 3 };
 165   const HashableDummy d_arr5[] = { {1}, {2}, {3} };
 166   hash_code arr5_hash = hash_combine_range(begin(arr5), end(arr5));
 167   hash_code d_arr5_hash = hash_combine_range(begin(d_arr5), end(d_arr5));
 168   EXPECT_EQ(arr5_hash, d_arr5_hash);
 169 }
 170
 171 TEST(HashingTest, HashCombineRangeLengthDiff) {
 172   // Test that as only the length varies, we compute different hash codes for
 173   // sequences.
 174   std::map<size_t, size_t> code_to_size;
 175   std::vector<char> all_one_c(256, '\xff');
 176   for (unsigned Idx = 1, Size = all_one_c.size(); Idx < Size; ++Idx) {
 177     hash_code code = hash_combine_range(&all_one_c[0], &all_one_c[0] + Idx);
 178     std::map<size_t, size_t>::iterator
 179       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 180     EXPECT_EQ(Idx, I->second);
 181   }
 182   code_to_size.clear();
 183   std::vector<char> all_zero_c(256, '\0');
 184   for (unsigned Idx = 1, Size = all_zero_c.size(); Idx < Size; ++Idx) {
 185     hash_code code = hash_combine_range(&all_zero_c[0], &all_zero_c[0] + Idx);
 186     std::map<size_t, size_t>::iterator
 187       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 188     EXPECT_EQ(Idx, I->second);
 189   }
 190   code_to_size.clear();
 191   std::vector<unsigned> all_one_int(512, -1);
 192   for (unsigned Idx = 1, Size = all_one_int.size(); Idx < Size; ++Idx) {
 193     hash_code code = hash_combine_range(&all_one_int[0], &all_one_int[0] + Idx);
 194     std::map<size_t, size_t>::iterator
 195       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 196     EXPECT_EQ(Idx, I->second);
 197   }
 198   code_to_size.clear();
 199   std::vector<unsigned> all_zero_int(512, 0);
 200   for (unsigned Idx = 1, Size = all_zero_int.size(); Idx < Size; ++Idx) {
 201     hash_code code = hash_combine_range(&all_zero_int[0], &all_zero_int[0] + Idx);
 202     std::map<size_t, size_t>::iterator
 203       I = code_to_size.insert(std::make_pair(code, Idx)).first;
 204     EXPECT_EQ(Idx, I->second);
 205   }
 206 }
 207
 208 TEST(HashingTest, HashCombineRangeGoldenTest) {
 209   struct { const char *s; uint64_t hash; } golden_data[] = {
 210 #if SIZE_MAX == UINT64_MAX || SIZE_MAX == UINT32_MAX
 211     { "a",                                0xaeb6f9d5517c61f8ULL },
 212     { "ab",                               0x7ab1edb96be496b4ULL },
 213     { "abc",                              0xe38e60bf19c71a3fULL },
 214     { "abcde",                            0xd24461a66de97f6eULL },
 215     { "abcdefgh",                         0x4ef872ec411dec9dULL },
 216     { "abcdefghijklm",                    0xe8a865539f4eadfeULL },
 217     { "abcdefghijklmnopqrstu",            0x261cdf85faaf4e79ULL },
 218     { "abcdefghijklmnopqrstuvwxyzabcdef", 0x43ba70e4198e3b2aULL },
 219     { "abcdefghijklmnopqrstuvwxyzabcdef"
 220       "abcdefghijklmnopqrstuvwxyzghijkl"
 221       "abcdefghijklmnopqrstuvwxyzmnopqr"
 222       "abcdefghijklmnopqrstuvwxyzstuvwx"
 223       "abcdefghijklmnopqrstuvwxyzyzabcd", 0xdcd57fb2afdf72beULL },
 224     { "a",                                0xaeb6f9d5517c61f8ULL },
 225     { "aa",                               0xf2b3b69a9736a1ebULL },
 226     { "aaa",                              0xf752eb6f07b1cafeULL },
 227     { "aaaaa",                            0x812bd21e1236954cULL },
 228     { "aaaaaaaa",                         0xff07a2cff08ac587ULL },
 229     { "aaaaaaaaaaaaa",                    0x84ac949d54d704ecULL },
 230     { "aaaaaaaaaaaaaaaaaaaaa",            0xcb2c8fb6be8f5648ULL },
 231     { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0xcc40ab7f164091b6ULL },
 232     { "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 233       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 234       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 235       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 236       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 0xc58e174c1e78ffe9ULL },
 237     { "z",                                0x1ba160d7e8f8785cULL },
 238     { "zz",                               0x2c5c03172f1285d7ULL },
 239     { "zzz",                              0x9d2c4f4b507a2ac3ULL },
 240     { "zzzzz",                            0x0f03b9031735693aULL },
 241     { "zzzzzzzz",                         0xe674147c8582c08eULL },
 242     { "zzzzzzzzzzzzz",                    0x3162d9fa6938db83ULL },
 243     { "zzzzzzzzzzzzzzzzzzzzz",            0x37b9a549e013620cULL },
 244     { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0x8921470aff885016ULL },
 245     { "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 246       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 247       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 248       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"
 249       "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz", 0xf60fdcd9beb08441ULL },
 250     { "a",                                0xaeb6f9d5517c61f8ULL },
 251     { "ab",                               0x7ab1edb96be496b4ULL },
 252     { "aba",                              0x3edb049950884d0aULL },
 253     { "ababa",                            0x8f2de9e73a97714bULL },
 254     { "abababab",                         0xee14a29ddf0ce54cULL },
 255     { "ababababababa",                    0x38b3ddaada2d52b4ULL },
 256     { "ababababababababababa",            0xd3665364219f2b85ULL },
 257     { "abababababababababababababababab", 0xa75cd6afbf1bc972ULL },
 258     { "abababababababababababababababab"
 259       "abababababababababababababababab"
 260       "abababababababababababababababab"
 261       "abababababababababababababababab"
 262       "abababababababababababababababab", 0x840192d129f7a22bULL }
 263 #else
 264 #error This test only supports 64-bit and 32-bit systems.
 265 #endif
 266   };
 267   for (unsigned i = 0; i < sizeof(golden_data)/sizeof(*golden_data); ++i) {
 268     StringRef str = golden_data[i].s;
 269     hash_code hash = hash_combine_range(str.begin(), str.end());
 270 #if 0 // Enable this to generate paste-able text for the above structure.
 271     std::string member_str = "\"" + str.str() + "\",";
 272     fprintf(stderr, " { %-35s 0x%016llxULL },\n",
 273             member_str.c_str(), static_cast<uint64_t>(hash));
 274 #endif
 275     EXPECT_EQ(static_cast<size_t>(golden_data[i].hash),
 276               static_cast<size_t>(hash));
 277   }
 278 }
 279
 280 TEST(HashingTest, HashCombineBasicTest) {
 281   // Hashing a sequence of homogenous types matches range hashing.
 282   const int i1 = 42, i2 = 43, i3 = 123, i4 = 999, i5 = 0, i6 = 79;
 283   const int arr1[] = { i1, i2, i3, i4, i5, i6 };
 284   EXPECT_EQ(hash_combine_range(arr1, arr1 + 1), hash_combine(i1));
 285   EXPECT_EQ(hash_combine_range(arr1, arr1 + 2), hash_combine(i1, i2));
 286   EXPECT_EQ(hash_combine_range(arr1, arr1 + 3), hash_combine(i1, i2, i3));
 287   EXPECT_EQ(hash_combine_range(arr1, arr1 + 4), hash_combine(i1, i2, i3, i4));
 288   EXPECT_EQ(hash_combine_range(arr1, arr1 + 5),
 289             hash_combine(i1, i2, i3, i4, i5));
 290   EXPECT_EQ(hash_combine_range(arr1, arr1 + 6),
 291             hash_combine(i1, i2, i3, i4, i5, i6));
 292
 293   // Hashing a sequence of heterogeneous types which *happen* to all produce the
 294   // same data for hashing produces the same as a range-based hash of the
 295   // fundamental values.
 296   const size_t s1 = 1024, s2 = 8888, s3 = 9000000;
 297   const HashableDummy d1 = { 1024 }, d2 = { 8888 }, d3 = { 9000000 };
 298   const size_t arr2[] = { s1, s2, s3 };
 299   EXPECT_EQ(hash_combine_range(begin(arr2), end(arr2)),
 300             hash_combine(s1, s2, s3));
 301   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(s1, s2, d3));
 302   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(s1, d2, s3));
 303   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, s2, s3));
 304   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, d2, s3));
 305   EXPECT_EQ(hash_combine(s1, s2, s3), hash_combine(d1, d2, d3));
 306
 307   // Permuting values causes hashes to change.
 308   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i1, i1, i2));
 309   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i1, i2, i1));
 310   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i1, i1));
 311   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i2, i1));
 312   EXPECT_NE(hash_combine(i1, i1, i1), hash_combine(i2, i2, i2));
 313   EXPECT_NE(hash_combine(i2, i1, i1), hash_combine(i1, i1, i2));
 314   EXPECT_NE(hash_combine(i1, i1, i2), hash_combine(i1, i2, i1));
 315   EXPECT_NE(hash_combine(i1, i2, i1), hash_combine(i2, i1, i1));
 316
 317   // Changing type w/o changing value causes hashes to change.
 318   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine((char)i1, i2, i3));
 319   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine(i1, (char)i2, i3));
 320   EXPECT_NE(hash_combine(i1, i2, i3), hash_combine(i1, i2, (char)i3));
 321
 322   // This is array of uint64, but it should have the exact same byte pattern as
 323   // an array of LargeTestIntegers.
 324   const uint64_t bigarr[] = {
 325     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 326     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 327     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 328     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 329     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 330     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 331     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 332     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 333     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL
 334   };
 335   // Hash a preposterously large integer, both aligned with the buffer and
 336   // misaligned.
 337   const LargeTestInteger li = { {
 338     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL,
 339     0xdeadbeafdeadbeefULL, 0xfefefefededededeULL, 0xafafafafededededULL,
 340     0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL
 341   } };
 342   // Rotate the storage from 'li'.
 343   const LargeTestInteger l2 = { {
 344     0xacacacacbcbcbcbcULL, 0xccddeeffeeddccbbULL, 0xdeadbeafdeadbeefULL,
 345     0xfefefefededededeULL, 0xafafafafededededULL, 0xffffeeeeddddccccULL,
 346     0xaaaacbcbffffababULL, 0xaaaaaaaaababababULL
 347   } };
 348   const LargeTestInteger l3 = { {
 349     0xccddeeffeeddccbbULL, 0xdeadbeafdeadbeefULL, 0xfefefefededededeULL,
 350     0xafafafafededededULL, 0xffffeeeeddddccccULL, 0xaaaacbcbffffababULL,
 351     0xaaaaaaaaababababULL, 0xacacacacbcbcbcbcULL
 352   } };
 353   EXPECT_EQ(hash_combine_range(begin(bigarr), end(bigarr)),
 354             hash_combine(li, li, li));
 355   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 9),
 356             hash_combine(bigarr[0], l2));
 357   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 10),
 358             hash_combine(bigarr[0], bigarr[1], l3));
 359   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 17),
 360             hash_combine(li, bigarr[0], l2));
 361   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 18),
 362             hash_combine(li, bigarr[0], bigarr[1], l3));
 363   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 18),
 364             hash_combine(bigarr[0], l2, bigarr[9], l3));
 365   EXPECT_EQ(hash_combine_range(bigarr, bigarr + 20),
 366             hash_combine(bigarr[0], l2, bigarr[9], l3, bigarr[18], bigarr[19]));
 367 }
 368
 369 TEST(HashingTest, HashCombineArgs18) {
 370   // This tests that we can pass in up to 18 args.
 371 #define CHECK_SAME(...)                                                        \
 372   EXPECT_EQ(hash_combine(__VA_ARGS__), hash_combine(__VA_ARGS__))
 373   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18);
 374   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17);
 375   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16);
 376   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15);
 377   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14);
 378   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13);
 379   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
 380   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11);
 381   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
 382   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8, 9);
 383   CHECK_SAME(1, 2, 3, 4, 5, 6, 7, 8);
 384   CHECK_SAME(1, 2, 3, 4, 5, 6, 7);
 385   CHECK_SAME(1, 2, 3, 4, 5, 6);
 386   CHECK_SAME(1, 2, 3, 4, 5);
 387   CHECK_SAME(1, 2, 3, 4);
 388   CHECK_SAME(1, 2, 3);
 389   CHECK_SAME(1, 2);
 390   CHECK_SAME(1);
 391 #undef CHECK_SAME
 392 }
 393
 394 }