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[libc++] Fix wrong implementation of CityHash
As PR56606 stated, the current implementation of CityHash in libc++ would drop some bits unintentionally. Cast the 32bit int to the 64bit int to avoid this happened. Reviewed By: ldionne, #libc Differential Revision: https://reviews.llvm.org/D134124
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libcxx/test/libcxx/utilities/utility/__murmur2_or_cityhash.pass.cpp
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//===----------------------------------------------------------------------===// | ||
// | ||
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | ||
// See https://llvm.org/LICENSE.txt for license information. | ||
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | ||
// | ||
//===----------------------------------------------------------------------===// | ||
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// Test the CityHash implementation is correct. | ||
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// UNSUPPORTED: c++03 | ||
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#include <cassert> | ||
#include <string> | ||
#include <utility> | ||
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#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ | ||
# define CHOOSE_BY_ENDIANESS(little, big) (little) | ||
#else | ||
# define CHOOSE_BY_ENDIANESS(little, big) (big) | ||
#endif | ||
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int main(int, char**) { | ||
const std::pair<std::string, uint64_t> TestCases[] = { | ||
{"abcdefgh", CHOOSE_BY_ENDIANESS(0x4382a8d0fe8edb17ULL, 0xca84e809bef16fbcULL)}, | ||
{"abcDefgh", CHOOSE_BY_ENDIANESS(0xecefb080a6854061ULL, 0xd7feb824250272dcULL)}, | ||
{"CityHash", CHOOSE_BY_ENDIANESS(0x169ea3aebf908d6dULL, 0xea8cef3ca6f6e368ULL)}, | ||
{"CitYHash", CHOOSE_BY_ENDIANESS(0xe18298a2760f09faULL, 0xf33a7700bb7a94a8ULL)}, | ||
}; | ||
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std::__murmur2_or_cityhash<uint64_t> h64; | ||
for (const auto& test_case : TestCases) { | ||
assert(h64(test_case.first.data(), test_case.first.size()) == test_case.second); | ||
} | ||
return 0; | ||
} |