diff options
Diffstat (limited to 'contrib/llvm-project/libcxx/include/__bit/countl.h')
| -rw-r--r-- | contrib/llvm-project/libcxx/include/__bit/countl.h | 84 |
1 files changed, 41 insertions, 43 deletions
diff --git a/contrib/llvm-project/libcxx/include/__bit/countl.h b/contrib/llvm-project/libcxx/include/__bit/countl.h index efc9e200b13a..396cfc2c3f40 100644 --- a/contrib/llvm-project/libcxx/include/__bit/countl.h +++ b/contrib/llvm-project/libcxx/include/__bit/countl.h @@ -24,18 +24,20 @@ _LIBCPP_PUSH_MACROS _LIBCPP_BEGIN_NAMESPACE_STD -_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR -int __libcpp_clz(unsigned __x) _NOEXCEPT { return __builtin_clz(__x); } +_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned __x) _NOEXCEPT { + return __builtin_clz(__x); +} -_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR -int __libcpp_clz(unsigned long __x) _NOEXCEPT { return __builtin_clzl(__x); } +_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned long __x) _NOEXCEPT { + return __builtin_clzl(__x); +} -_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR -int __libcpp_clz(unsigned long long __x) _NOEXCEPT { return __builtin_clzll(__x); } +_LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(unsigned long long __x) _NOEXCEPT { + return __builtin_clzll(__x); +} -# ifndef _LIBCPP_HAS_NO_INT128 -inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR -int __libcpp_clz(__uint128_t __x) _NOEXCEPT { +#ifndef _LIBCPP_HAS_NO_INT128 +inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int __libcpp_clz(__uint128_t __x) _NOEXCEPT { // The function is written in this form due to C++ constexpr limitations. // The algorithm: // - Test whether any bit in the high 64-bits is set @@ -45,42 +47,38 @@ int __libcpp_clz(__uint128_t __x) _NOEXCEPT { // - Any bits set: // - The number of leading zeros of the input is the number of leading // zeros in the high 64-bits. - return ((__x >> 64) == 0) - ? (64 + __builtin_clzll(static_cast<unsigned long long>(__x))) - : __builtin_clzll(static_cast<unsigned long long>(__x >> 64)); + return ((__x >> 64) == 0) ? (64 + __builtin_clzll(static_cast<unsigned long long>(__x))) + : __builtin_clzll(static_cast<unsigned long long>(__x >> 64)); } -# endif // _LIBCPP_HAS_NO_INT128 - -template<class _Tp> -_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 -int __countl_zero(_Tp __t) _NOEXCEPT -{ - static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__countl_zero requires an unsigned integer type"); - if (__t == 0) - return numeric_limits<_Tp>::digits; - - if (sizeof(_Tp) <= sizeof(unsigned int)) - return std::__libcpp_clz(static_cast<unsigned int>(__t)) - - (numeric_limits<unsigned int>::digits - numeric_limits<_Tp>::digits); - else if (sizeof(_Tp) <= sizeof(unsigned long)) - return std::__libcpp_clz(static_cast<unsigned long>(__t)) - - (numeric_limits<unsigned long>::digits - numeric_limits<_Tp>::digits); - else if (sizeof(_Tp) <= sizeof(unsigned long long)) - return std::__libcpp_clz(static_cast<unsigned long long>(__t)) - - (numeric_limits<unsigned long long>::digits - numeric_limits<_Tp>::digits); - else - { - int __ret = 0; - int __iter = 0; - const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits; - while (true) { - __t = std::__rotl(__t, __ulldigits); - if ((__iter = std::__countl_zero(static_cast<unsigned long long>(__t))) != __ulldigits) - break; - __ret += __iter; - } - return __ret + __iter; +#endif // _LIBCPP_HAS_NO_INT128 + +template <class _Tp> +_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int __countl_zero(_Tp __t) _NOEXCEPT { + static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__countl_zero requires an unsigned integer type"); + if (__t == 0) + return numeric_limits<_Tp>::digits; + + if (sizeof(_Tp) <= sizeof(unsigned int)) + return std::__libcpp_clz(static_cast<unsigned int>(__t)) - + (numeric_limits<unsigned int>::digits - numeric_limits<_Tp>::digits); + else if (sizeof(_Tp) <= sizeof(unsigned long)) + return std::__libcpp_clz(static_cast<unsigned long>(__t)) - + (numeric_limits<unsigned long>::digits - numeric_limits<_Tp>::digits); + else if (sizeof(_Tp) <= sizeof(unsigned long long)) + return std::__libcpp_clz(static_cast<unsigned long long>(__t)) - + (numeric_limits<unsigned long long>::digits - numeric_limits<_Tp>::digits); + else { + int __ret = 0; + int __iter = 0; + const unsigned int __ulldigits = numeric_limits<unsigned long long>::digits; + while (true) { + __t = std::__rotl(__t, __ulldigits); + if ((__iter = std::__countl_zero(static_cast<unsigned long long>(__t))) != __ulldigits) + break; + __ret += __iter; } + return __ret + __iter; + } } #if _LIBCPP_STD_VER >= 20 |