1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #ifndef _LIBCPP___CXX03___ALGORITHM_FILL_N_H
10 #define _LIBCPP___CXX03___ALGORITHM_FILL_N_H
11
12 #include <__cxx03/__algorithm/min.h>
13 #include <__cxx03/__config>
14 #include <__cxx03/__fwd/bit_reference.h>
15 #include <__cxx03/__iterator/iterator_traits.h>
16 #include <__cxx03/__memory/pointer_traits.h>
17 #include <__cxx03/__utility/convert_to_integral.h>
18
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 # pragma GCC system_header
21 #endif
22
23 _LIBCPP_PUSH_MACROS
24 #include <__cxx03/__undef_macros>
25
26 _LIBCPP_BEGIN_NAMESPACE_STD
27
28 // fill_n isn't specialized for std::memset, because the compiler already optimizes the loop to a call to std::memset.
29
30 template <class _OutputIterator, class _Size, class _Tp>
31 inline _LIBCPP_HIDE_FROM_ABI _OutputIterator __fill_n(_OutputIterator __first, _Size __n, const _Tp& __value);
32
33 template <bool _FillVal, class _Cp>
__fill_n_bool(__bit_iterator<_Cp,false> __first,typename _Cp::size_type __n)34 _LIBCPP_HIDE_FROM_ABI void __fill_n_bool(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n) {
35 using _It = __bit_iterator<_Cp, false>;
36 using __storage_type = typename _It::__storage_type;
37
38 const int __bits_per_word = _It::__bits_per_word;
39 // do first partial word
40 if (__first.__ctz_ != 0) {
41 __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
42 __storage_type __dn = std::min(__clz_f, __n);
43 __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
44 if (_FillVal)
45 *__first.__seg_ |= __m;
46 else
47 *__first.__seg_ &= ~__m;
48 __n -= __dn;
49 ++__first.__seg_;
50 }
51 // do middle whole words
52 __storage_type __nw = __n / __bits_per_word;
53 std::__fill_n(std::__to_address(__first.__seg_), __nw, _FillVal ? static_cast<__storage_type>(-1) : 0);
54 __n -= __nw * __bits_per_word;
55 // do last partial word
56 if (__n > 0) {
57 __first.__seg_ += __nw;
58 __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
59 if (_FillVal)
60 *__first.__seg_ |= __m;
61 else
62 *__first.__seg_ &= ~__m;
63 }
64 }
65
66 template <class _Cp, class _Size>
67 inline _LIBCPP_HIDE_FROM_ABI __bit_iterator<_Cp, false>
__fill_n(__bit_iterator<_Cp,false> __first,_Size __n,const bool & __value)68 __fill_n(__bit_iterator<_Cp, false> __first, _Size __n, const bool& __value) {
69 if (__n > 0) {
70 if (__value)
71 std::__fill_n_bool<true>(__first, __n);
72 else
73 std::__fill_n_bool<false>(__first, __n);
74 }
75 return __first + __n;
76 }
77
78 template <class _OutputIterator, class _Size, class _Tp>
__fill_n(_OutputIterator __first,_Size __n,const _Tp & __value)79 inline _LIBCPP_HIDE_FROM_ABI _OutputIterator __fill_n(_OutputIterator __first, _Size __n, const _Tp& __value) {
80 for (; __n > 0; ++__first, (void)--__n)
81 *__first = __value;
82 return __first;
83 }
84
85 template <class _OutputIterator, class _Size, class _Tp>
fill_n(_OutputIterator __first,_Size __n,const _Tp & __value)86 inline _LIBCPP_HIDE_FROM_ABI _OutputIterator fill_n(_OutputIterator __first, _Size __n, const _Tp& __value) {
87 return std::__fill_n(__first, std::__convert_to_integral(__n), __value);
88 }
89
90 _LIBCPP_END_NAMESPACE_STD
91
92 _LIBCPP_POP_MACROS
93
94 #endif // _LIBCPP___CXX03___ALGORITHM_FILL_N_H
95