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703cfe745b
`__libcpp_popcount` was previously used as a fallback for `__builtin_popcountg` to ensure compatibility with older compilers (Clang 18 and earlier), as `__builtin_popcountg` became available in Clang 19. Now that support for Clang 18 has been officially dropped in #130142, we can now safely replace all instances of `__libcpp_popcount` with `__builtin_popcountg` and eliminate the fallback logic.
47 lines
1.2 KiB
C++
47 lines
1.2 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP___BIT_POPCOUNT_H
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#define _LIBCPP___BIT_POPCOUNT_H
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#include <__bit/rotate.h>
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#include <__concepts/arithmetic.h>
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#include <__config>
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#include <__type_traits/is_unsigned.h>
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#include <limits>
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#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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# pragma GCC system_header
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#endif
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_LIBCPP_PUSH_MACROS
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#include <__undef_macros>
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_LIBCPP_BEGIN_NAMESPACE_STD
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template <class _Tp>
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[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __popcount(_Tp __t) _NOEXCEPT {
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static_assert(is_unsigned<_Tp>::value, "__popcount only works with unsigned types");
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return __builtin_popcountg(__t);
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}
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#if _LIBCPP_STD_VER >= 20
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template <__libcpp_unsigned_integer _Tp>
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[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr int popcount(_Tp __t) noexcept {
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return std::__popcount(__t);
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}
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#endif
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_LIBCPP_END_NAMESPACE_STD
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_LIBCPP_POP_MACROS
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#endif // _LIBCPP___BIT_POPCOUNT_H
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