From c388690a8b96cbdfa8c38a1e050088201da648e5 Mon Sep 17 00:00:00 2001 From: Nikolas Klauser Date: Wed, 27 Mar 2024 16:54:50 +0100 Subject: [PATCH] [libc++][NFC] Simplify copy and move lowering to memmove a bit (#83574) We've introduced `__constexpr_memmove` a while ago, which simplified the implementation of the copy and move lowering a bit. This allows us to remove some of the boilerplate. --- libcxx/include/__algorithm/copy.h | 6 +-- libcxx/include/__algorithm/copy_backward.h | 6 +-- libcxx/include/__algorithm/copy_move_common.h | 39 ++++--------------- libcxx/include/__algorithm/move.h | 6 +-- libcxx/include/__algorithm/move_backward.h | 6 +-- 5 files changed, 15 insertions(+), 48 deletions(-) diff --git a/libcxx/include/__algorithm/copy.h b/libcxx/include/__algorithm/copy.h index 4c3815405af0cf..0890b895f54092 100644 --- a/libcxx/include/__algorithm/copy.h +++ b/libcxx/include/__algorithm/copy.h @@ -32,7 +32,7 @@ template inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> __copy(_InIter, _Sent, _OutIter); template -struct __copy_loop { +struct __copy_impl { template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> operator()(_InIter __first, _Sent __last, _OutIter __result) const { @@ -94,9 +94,7 @@ struct __copy_loop { __local_first = _Traits::__begin(++__segment_iterator); } } -}; -struct __copy_trivial { // At this point, the iterators have been unwrapped so any `contiguous_iterator` has been unwrapped to a pointer. template ::value, int> = 0> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*> @@ -108,7 +106,7 @@ struct __copy_trivial { template pair<_InIter, _OutIter> inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 __copy(_InIter __first, _Sent __last, _OutIter __result) { - return std::__dispatch_copy_or_move<_AlgPolicy, __copy_loop<_AlgPolicy>, __copy_trivial>( + return std::__copy_move_unwrap_iters<__copy_impl<_AlgPolicy> >( std::move(__first), std::move(__last), std::move(__result)); } diff --git a/libcxx/include/__algorithm/copy_backward.h b/libcxx/include/__algorithm/copy_backward.h index 591dd21e2b032e..73dc846a975a44 100644 --- a/libcxx/include/__algorithm/copy_backward.h +++ b/libcxx/include/__algorithm/copy_backward.h @@ -33,7 +33,7 @@ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_InIter, _OutIter> __copy_backward(_InIter __first, _Sent __last, _OutIter __result); template -struct __copy_backward_loop { +struct __copy_backward_impl { template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> operator()(_InIter __first, _Sent __last, _OutIter __result) const { @@ -104,9 +104,7 @@ struct __copy_backward_loop { __local_last = _Traits::__end(__segment_iterator); } } -}; -struct __copy_backward_trivial { // At this point, the iterators have been unwrapped so any `contiguous_iterator` has been unwrapped to a pointer. template ::value, int> = 0> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*> @@ -118,7 +116,7 @@ struct __copy_backward_trivial { template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_BidirectionalIterator1, _BidirectionalIterator2> __copy_backward(_BidirectionalIterator1 __first, _Sentinel __last, _BidirectionalIterator2 __result) { - return std::__dispatch_copy_or_move<_AlgPolicy, __copy_backward_loop<_AlgPolicy>, __copy_backward_trivial>( + return std::__copy_move_unwrap_iters<__copy_backward_impl<_AlgPolicy> >( std::move(__first), std::move(__last), std::move(__result)); } diff --git a/libcxx/include/__algorithm/copy_move_common.h b/libcxx/include/__algorithm/copy_move_common.h index 845967b05038d6..12a26c6d6a64ee 100644 --- a/libcxx/include/__algorithm/copy_move_common.h +++ b/libcxx/include/__algorithm/copy_move_common.h @@ -81,30 +81,17 @@ __copy_backward_trivial_impl(_In* __first, _In* __last, _Out* __result) { // Iterator unwrapping and dispatching to the correct overload. -template -struct __overload : _F1, _F2 { - using _F1::operator(); - using _F2::operator(); -}; - -template -struct __can_rewrap : false_type {}; - -template -struct __can_rewrap<_InIter, - _Sent, - _OutIter, - // Note that sentinels are always copy-constructible. - __enable_if_t< is_copy_constructible<_InIter>::value && is_copy_constructible<_OutIter>::value > > - : true_type {}; +template +struct __can_rewrap + : integral_constant::value && is_copy_constructible<_OutIter>::value> {}; template ::value, int> = 0> + __enable_if_t<__can_rewrap<_InIter, _OutIter>::value, int> = 0> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 pair<_InIter, _OutIter> -__unwrap_and_dispatch(_InIter __first, _Sent __last, _OutIter __out_first) { +__copy_move_unwrap_iters(_InIter __first, _Sent __last, _OutIter __out_first) { auto __range = std::__unwrap_range(__first, std::move(__last)); auto __result = _Algorithm()(std::move(__range.first), std::move(__range.second), std::__unwrap_iter(__out_first)); return std::make_pair(std::__rewrap_range<_Sent>(std::move(__first), std::move(__result.first)), @@ -115,24 +102,12 @@ template ::value, int> = 0> + __enable_if_t::value, int> = 0> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 pair<_InIter, _OutIter> -__unwrap_and_dispatch(_InIter __first, _Sent __last, _OutIter __out_first) { +__copy_move_unwrap_iters(_InIter __first, _Sent __last, _OutIter __out_first) { return _Algorithm()(std::move(__first), std::move(__last), std::move(__out_first)); } -template -_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX17 pair<_InIter, _OutIter> -__dispatch_copy_or_move(_InIter __first, _Sent __last, _OutIter __out_first) { - using _Algorithm = __overload<_NaiveAlgorithm, _OptimizedAlgorithm>; - return std::__unwrap_and_dispatch<_Algorithm>(std::move(__first), std::move(__last), std::move(__out_first)); -} - _LIBCPP_END_NAMESPACE_STD _LIBCPP_POP_MACROS diff --git a/libcxx/include/__algorithm/move.h b/libcxx/include/__algorithm/move.h index bf574b5274093d..1716d43e2a613d 100644 --- a/libcxx/include/__algorithm/move.h +++ b/libcxx/include/__algorithm/move.h @@ -34,7 +34,7 @@ inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIte __move(_InIter __first, _Sent __last, _OutIter __result); template -struct __move_loop { +struct __move_impl { template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> operator()(_InIter __first, _Sent __last, _OutIter __result) const { @@ -95,9 +95,7 @@ struct __move_loop { __local_first = _Traits::__begin(++__segment_iterator); } } -}; -struct __move_trivial { // At this point, the iterators have been unwrapped so any `contiguous_iterator` has been unwrapped to a pointer. template ::value, int> = 0> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*> @@ -109,7 +107,7 @@ struct __move_trivial { template inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> __move(_InIter __first, _Sent __last, _OutIter __result) { - return std::__dispatch_copy_or_move<_AlgPolicy, __move_loop<_AlgPolicy>, __move_trivial>( + return std::__copy_move_unwrap_iters<__move_impl<_AlgPolicy> >( std::move(__first), std::move(__last), std::move(__result)); } diff --git a/libcxx/include/__algorithm/move_backward.h b/libcxx/include/__algorithm/move_backward.h index 6bb7c91d66c7ce..4beb7bdbaac0d0 100644 --- a/libcxx/include/__algorithm/move_backward.h +++ b/libcxx/include/__algorithm/move_backward.h @@ -33,7 +33,7 @@ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_BidirectionalIterator1 __move_backward(_BidirectionalIterator1 __first, _Sentinel __last, _BidirectionalIterator2 __result); template -struct __move_backward_loop { +struct __move_backward_impl { template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_InIter, _OutIter> operator()(_InIter __first, _Sent __last, _OutIter __result) const { @@ -104,9 +104,7 @@ struct __move_backward_loop { __local_last = _Traits::__end(--__segment_iterator); } } -}; -struct __move_backward_trivial { // At this point, the iterators have been unwrapped so any `contiguous_iterator` has been unwrapped to a pointer. template ::value, int> = 0> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 pair<_In*, _Out*> @@ -122,7 +120,7 @@ __move_backward(_BidirectionalIterator1 __first, _Sentinel __last, _Bidirectiona std::is_copy_constructible<_BidirectionalIterator1>::value, "Iterators must be copy constructible."); - return std::__dispatch_copy_or_move<_AlgPolicy, __move_backward_loop<_AlgPolicy>, __move_backward_trivial>( + return std::__copy_move_unwrap_iters<__move_backward_impl<_AlgPolicy> >( std::move(__first), std::move(__last), std::move(__result)); }