mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-12 09:17:53 +00:00
98 lines
3.3 KiB
C++
98 lines
3.3 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef _LIBCPP___ALGORITHM_FILL_N_H
|
|
#define _LIBCPP___ALGORITHM_FILL_N_H
|
|
|
|
#include <__algorithm/min.h>
|
|
#include <__config>
|
|
#include <__fwd/bit_reference.h>
|
|
#include <__iterator/iterator_traits.h>
|
|
#include <__memory/pointer_traits.h>
|
|
#include <__utility/convert_to_integral.h>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_PUSH_MACROS
|
|
#include <__undef_macros>
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
// fill_n isn't specialized for std::memset, because the compiler already optimizes the loop to a call to std::memset.
|
|
|
|
template <class _OutputIterator, class _Size, class _Tp>
|
|
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
|
|
__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value);
|
|
|
|
template <bool _FillVal, class _Cp>
|
|
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
|
|
__fill_n_bool(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n) {
|
|
using _It = __bit_iterator<_Cp, false>;
|
|
using __storage_type = typename _It::__storage_type;
|
|
|
|
const int __bits_per_word = _It::__bits_per_word;
|
|
// do first partial word
|
|
if (__first.__ctz_ != 0) {
|
|
__storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
|
|
__storage_type __dn = std::min(__clz_f, __n);
|
|
__storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
|
|
if (_FillVal)
|
|
*__first.__seg_ |= __m;
|
|
else
|
|
*__first.__seg_ &= ~__m;
|
|
__n -= __dn;
|
|
++__first.__seg_;
|
|
}
|
|
// do middle whole words
|
|
__storage_type __nw = __n / __bits_per_word;
|
|
std::__fill_n(std::__to_address(__first.__seg_), __nw, _FillVal ? static_cast<__storage_type>(-1) : 0);
|
|
__n -= __nw * __bits_per_word;
|
|
// do last partial word
|
|
if (__n > 0) {
|
|
__first.__seg_ += __nw;
|
|
__storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
|
|
if (_FillVal)
|
|
*__first.__seg_ |= __m;
|
|
else
|
|
*__first.__seg_ &= ~__m;
|
|
}
|
|
}
|
|
|
|
template <class _Cp, class _Size>
|
|
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator<_Cp, false>
|
|
__fill_n(__bit_iterator<_Cp, false> __first, _Size __n, const bool& __value) {
|
|
if (__n > 0) {
|
|
if (__value)
|
|
std::__fill_n_bool<true>(__first, __n);
|
|
else
|
|
std::__fill_n_bool<false>(__first, __n);
|
|
}
|
|
return __first + __n;
|
|
}
|
|
|
|
template <class _OutputIterator, class _Size, class _Tp>
|
|
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
|
|
__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value) {
|
|
for (; __n > 0; ++__first, (void)--__n)
|
|
*__first = __value;
|
|
return __first;
|
|
}
|
|
|
|
template <class _OutputIterator, class _Size, class _Tp>
|
|
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator
|
|
fill_n(_OutputIterator __first, _Size __n, const _Tp& __value) {
|
|
return std::__fill_n(__first, std::__convert_to_integral(__n), __value);
|
|
}
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
_LIBCPP_POP_MACROS
|
|
|
|
#endif // _LIBCPP___ALGORITHM_FILL_N_H
|