diff options
| -rw-r--r-- | AK/HashFunctions.h | 14 | ||||
| -rw-r--r-- | Tests/AK/TestHashFunctions.cpp | 5 |
2 files changed, 12 insertions, 7 deletions
diff --git a/AK/HashFunctions.h b/AK/HashFunctions.h index 951619c4a7..e869b44800 100644 --- a/AK/HashFunctions.h +++ b/AK/HashFunctions.h @@ -21,11 +21,15 @@ constexpr unsigned int_hash(u32 key) constexpr unsigned double_hash(u32 key) { - key = ~key + (key >> 23); - key ^= (key << 12); - key ^= (key >> 7); - key ^= (key << 2); - key ^= (key >> 20); + const unsigned magic = 0xBA5EDB01; + if (key == magic) + return 0u; + if (key == 0u) + key = magic; + + key ^= key << 13; + key ^= key >> 17; + key ^= key << 5; return key; } diff --git a/Tests/AK/TestHashFunctions.cpp b/Tests/AK/TestHashFunctions.cpp index fa8eafae9e..6fbb0ab6f7 100644 --- a/Tests/AK/TestHashFunctions.cpp +++ b/Tests/AK/TestHashFunctions.cpp @@ -17,8 +17,9 @@ TEST_CASE(int_hash) TEST_CASE(double_hash) { - static_assert(double_hash(42) == 524450u); - static_assert(double_hash(0) == 12384u); + static_assert(double_hash(666) == 171644115u); + static_assert(double_hash(0) == 1189591134u); + static_assert(double_hash(0xBA5EDB01) == 0u); } TEST_CASE(pair_int_hash) |