[libcxx-commits] [libcxx] [libcxx] Added segment iterator for fill (PR #104680)
via libcxx-commits
libcxx-commits at lists.llvm.org
Sat Aug 17 13:43:37 PDT 2024
https://github.com/NoumanAmir657 updated https://github.com/llvm/llvm-project/pull/104680
>From 2782a4cf1b62a7db53d7cb6a3543db0259f4ef5e Mon Sep 17 00:00:00 2001
From: nouman-10x <noumanamir453 at gmail.com>
Date: Sat, 17 Aug 2024 23:18:52 +0500
Subject: [PATCH 1/4] [libcxx] Added segment iterator for fill
---
libcxx/include/__algorithm/fill.h | 53 +++++++++++++++++++++++++++----
1 file changed, 47 insertions(+), 6 deletions(-)
diff --git a/libcxx/include/__algorithm/fill.h b/libcxx/include/__algorithm/fill.h
index 1ce3eadb013d05..3ba37e7260a4a2 100644
--- a/libcxx/include/__algorithm/fill.h
+++ b/libcxx/include/__algorithm/fill.h
@@ -21,25 +21,66 @@ _LIBCPP_BEGIN_NAMESPACE_STD
// fill isn't specialized for std::memset, because the compiler already optimizes the loop to a call to std::memset.
-template <class _ForwardIterator, class _Tp>
+template <
+ class _ForwardIterator,
+ class _Tp,
+ __enable_if_t<
+ is_same<typename iterator_traits<_ForwardIterator>::iterator_category, forward_iterator_tag>::value ||
+ is_same<typename iterator_traits<_ForwardIterator>::iterator_category, bidirectional_iterator_tag>::value,
+ int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
-__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, forward_iterator_tag) {
+__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
for (; __first != __last; ++__first)
*__first = __value;
}
-template <class _RandomAccessIterator, class _Tp>
+template <class _RandomAccessIterator,
+ class _Tp,
+ __enable_if_t<(is_same<typename iterator_traits<_RandomAccessIterator>::iterator_category,
+ random_access_iterator_tag>::value ||
+ is_same<typename iterator_traits<_RandomAccessIterator>::iterator_category,
+ contiguous_iterator_tag>::value) &&
+ !__is_segmented_iterator<_RandomAccessIterator>::value,
+ int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
-__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value, random_access_iterator_tag) {
+__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value) {
std::fill_n(__first, __last - __first, __value);
}
+template <class _SegmentedIterator,
+ class _Tp,
+ __enable_if_t<__is_segmented_iterator<_SegmentedIterator>::value, int> = 0>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
+__fill(_SegmentedIterator __first, _SegmentedIterator __last, const _Tp& __value) {
+ using _Traits = __segmented_iterator_traits<_SegmentedIterator>;
+
+ auto __sfirst = _Traits::__segment(__first);
+ auto __slast = _Traits::__segment(__last);
+
+ // We are in a single segment, so we might not be at the beginning or end
+ if (__sfirst == __slast) {
+ __fill(_Traits::__local(__first), _Traits::__local(__last), __value);
+ return;
+ }
+
+ // We have more than one segment. Iterate over the first segment, since we might not start at the beginning
+ __fill(_Traits::__local(__first), _Traits::__end(__sfirst), __value);
+ ++__sfirst;
+ // iterate over the segments which are guaranteed to be completely in the range
+ while (__sfirst != __slast) {
+ __fill(_Traits::__begin(__sfirst), _Traits::__end(__sfirst), __value);
+ ++__sfirst;
+ }
+ // iterate over the last segment
+ __fill(_Traits::__begin(__sfirst), _Traits::__local(__last), __value);
+}
+
template <class _ForwardIterator, class _Tp>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
- std::__fill(__first, __last, __value, typename iterator_traits<_ForwardIterator>::iterator_category());
+ std::__fill(__first, __last, __value);
}
_LIBCPP_END_NAMESPACE_STD
-#endif // _LIBCPP___ALGORITHM_FILL_H
+#endif // _LIBCPP___ALGORITHM_FILL_H
\ No newline at end of file
>From 9caf495c7e6e17ffd9da59858f33246f825a0b02 Mon Sep 17 00:00:00 2001
From: nouman-10x <noumanamir453 at gmail.com>
Date: Sat, 17 Aug 2024 23:37:14 +0500
Subject: [PATCH 2/4] Fixed newline
---
libcxx/include/__algorithm/fill.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libcxx/include/__algorithm/fill.h b/libcxx/include/__algorithm/fill.h
index 3ba37e7260a4a2..da2bda4713c373 100644
--- a/libcxx/include/__algorithm/fill.h
+++ b/libcxx/include/__algorithm/fill.h
@@ -83,4 +83,4 @@ fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
_LIBCPP_END_NAMESPACE_STD
-#endif // _LIBCPP___ALGORITHM_FILL_H
\ No newline at end of file
+#endif // _LIBCPP___ALGORITHM_FILL_H
>From 37dab9d3dfc627b8ca7b14ad3475caab2c4f81cd Mon Sep 17 00:00:00 2001
From: nouman-10x <noumanamir453 at gmail.com>
Date: Sun, 18 Aug 2024 00:57:05 +0500
Subject: [PATCH 3/4] Fixed the logic of templates
---
libcxx/include/__algorithm/fill.h | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/libcxx/include/__algorithm/fill.h b/libcxx/include/__algorithm/fill.h
index da2bda4713c373..b8d893e2ee7339 100644
--- a/libcxx/include/__algorithm/fill.h
+++ b/libcxx/include/__algorithm/fill.h
@@ -12,6 +12,7 @@
#include <__algorithm/fill_n.h>
#include <__config>
#include <__iterator/iterator_traits.h>
+#include <__iterator/segmented_iterator.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
@@ -24,10 +25,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
template <
class _ForwardIterator,
class _Tp,
- __enable_if_t<
- is_same<typename iterator_traits<_ForwardIterator>::iterator_category, forward_iterator_tag>::value ||
- is_same<typename iterator_traits<_ForwardIterator>::iterator_category, bidirectional_iterator_tag>::value,
- int> = 0>
+ __enable_if_t<!__has_random_access_iterator_category<_ForwardIterator>::value, int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
for (; __first != __last; ++__first)
@@ -36,12 +34,8 @@ __fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
template <class _RandomAccessIterator,
class _Tp,
- __enable_if_t<(is_same<typename iterator_traits<_RandomAccessIterator>::iterator_category,
- random_access_iterator_tag>::value ||
- is_same<typename iterator_traits<_RandomAccessIterator>::iterator_category,
- contiguous_iterator_tag>::value) &&
- !__is_segmented_iterator<_RandomAccessIterator>::value,
- int> = 0>
+ __enable_if_t<__has_random_access_iterator_category<_RandomAccessIterator>::value &&
+ !__is_segmented_iterator<_RandomAccessIterator>::value, int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value) {
std::fill_n(__first, __last - __first, __value);
>From 8bb83d67e8dd050be8b06d2a1b93327c4e2b0dfb Mon Sep 17 00:00:00 2001
From: nouman-10x <noumanamir453 at gmail.com>
Date: Sun, 18 Aug 2024 01:42:46 +0500
Subject: [PATCH 4/4] Used std::for_each to remove redundant code
---
libcxx/include/__algorithm/fill.h | 49 ++++++++++++++++---------------
1 file changed, 26 insertions(+), 23 deletions(-)
diff --git a/libcxx/include/__algorithm/fill.h b/libcxx/include/__algorithm/fill.h
index b8d893e2ee7339..32439f03dc9cff 100644
--- a/libcxx/include/__algorithm/fill.h
+++ b/libcxx/include/__algorithm/fill.h
@@ -10,6 +10,7 @@
#define _LIBCPP___ALGORITHM_FILL_H
#include <__algorithm/fill_n.h>
+#include <__algorithm/for_each.h>
#include <__config>
#include <__iterator/iterator_traits.h>
#include <__iterator/segmented_iterator.h>
@@ -22,10 +23,9 @@ _LIBCPP_BEGIN_NAMESPACE_STD
// fill isn't specialized for std::memset, because the compiler already optimizes the loop to a call to std::memset.
-template <
- class _ForwardIterator,
- class _Tp,
- __enable_if_t<!__has_random_access_iterator_category<_ForwardIterator>::value, int> = 0>
+template < class _ForwardIterator,
+ class _Tp,
+ __enable_if_t<!__has_random_access_iterator_category<_ForwardIterator>::value, int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
for (; __first != __last; ++__first)
@@ -35,7 +35,8 @@ __fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
template <class _RandomAccessIterator,
class _Tp,
__enable_if_t<__has_random_access_iterator_category<_RandomAccessIterator>::value &&
- !__is_segmented_iterator<_RandomAccessIterator>::value, int> = 0>
+ !__is_segmented_iterator<_RandomAccessIterator>::value,
+ int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value) {
std::fill_n(__first, __last - __first, __value);
@@ -46,27 +47,29 @@ template <class _SegmentedIterator,
__enable_if_t<__is_segmented_iterator<_SegmentedIterator>::value, int> = 0>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
__fill(_SegmentedIterator __first, _SegmentedIterator __last, const _Tp& __value) {
- using _Traits = __segmented_iterator_traits<_SegmentedIterator>;
+ // using _Traits = __segmented_iterator_traits<_SegmentedIterator>;
- auto __sfirst = _Traits::__segment(__first);
- auto __slast = _Traits::__segment(__last);
+ // auto __sfirst = _Traits::__segment(__first);
+ // auto __slast = _Traits::__segment(__last);
- // We are in a single segment, so we might not be at the beginning or end
- if (__sfirst == __slast) {
- __fill(_Traits::__local(__first), _Traits::__local(__last), __value);
- return;
- }
+ // // We are in a single segment, so we might not be at the beginning or end
+ // if (__sfirst == __slast) {
+ // __fill(_Traits::__local(__first), _Traits::__local(__last), __value);
+ // return;
+ // }
- // We have more than one segment. Iterate over the first segment, since we might not start at the beginning
- __fill(_Traits::__local(__first), _Traits::__end(__sfirst), __value);
- ++__sfirst;
- // iterate over the segments which are guaranteed to be completely in the range
- while (__sfirst != __slast) {
- __fill(_Traits::__begin(__sfirst), _Traits::__end(__sfirst), __value);
- ++__sfirst;
- }
- // iterate over the last segment
- __fill(_Traits::__begin(__sfirst), _Traits::__local(__last), __value);
+ // // We have more than one segment. Iterate over the first segment, since we might not start at the beginning
+ // __fill(_Traits::__local(__first), _Traits::__end(__sfirst), __value);
+ // ++__sfirst;
+ // // iterate over the segments which are guaranteed to be completely in the range
+ // while (__sfirst != __slast) {
+ // __fill(_Traits::__begin(__sfirst), _Traits::__end(__sfirst), __value);
+ // ++__sfirst;
+ // }
+ // // iterate over the last segment
+ // __fill(_Traits::__begin(__sfirst), _Traits::__local(__last), __value);
+
+ std::for_each(__first, __last, [__value](_Tp& val) { val = __value; });
}
template <class _ForwardIterator, class _Tp>
More information about the libcxx-commits
mailing list