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Diffstat (limited to 'libcxx/include/__pstl/internal/parallel_impl.h')
| -rw-r--r-- | libcxx/include/__pstl/internal/parallel_impl.h | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/libcxx/include/__pstl/internal/parallel_impl.h b/libcxx/include/__pstl/internal/parallel_impl.h deleted file mode 100644 index 740f1376a8f4..000000000000 --- a/libcxx/include/__pstl/internal/parallel_impl.h +++ /dev/null @@ -1,91 +0,0 @@ -// -*- 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 _PSTL_PARALLEL_IMPL_H -#define _PSTL_PARALLEL_IMPL_H - -#include <__atomic/atomic.h> -#include <__atomic/memory_order.h> -#include <__config> -#include <__iterator/iterator_traits.h> -#include <__pstl/internal/parallel_backend.h> -#include <__pstl/internal/parallel_backend_serial.h> -#include <__utility/forward.h> - -#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17 - -namespace __pstl -{ -namespace __internal -{ - -//------------------------------------------------------------------------ -// parallel_find -//----------------------------------------------------------------------- -/** Return extremum value returned by brick f[i,j) for subranges [i,j) of [first,last) -Each f[i,j) must return a value in [i,j). */ -template <class _BackendTag, class _ExecutionPolicy, class _Index, class _Brick, class _Compare> -_LIBCPP_HIDE_FROM_ABI _Index -__parallel_find(_BackendTag __tag, _ExecutionPolicy&& __exec, _Index __first, _Index __last, _Brick __f, - _Compare __comp, bool __b_first) -{ - typedef typename std::iterator_traits<_Index>::difference_type _DifferenceType; - const _DifferenceType __n = __last - __first; - _DifferenceType __initial_dist = __b_first ? __n : -1; - std::atomic<_DifferenceType> __extremum(__initial_dist); - // TODO: find out what is better here: parallel_for or parallel_reduce - __par_backend::__parallel_for(__tag, std::forward<_ExecutionPolicy>(__exec), __first, __last, - [__comp, __f, __first, &__extremum](_Index __i, _Index __j) - { - // See "Reducing Contention Through Priority Updates", PPoPP '13, for discussion of - // why using a shared variable scales fairly well in this situation. - if (__comp(__i - __first, __extremum)) - { - _Index __res = __f(__i, __j); - // If not '__last' returned then we found what we want so put this to extremum - if (__res != __j) - { - const _DifferenceType __k = __res - __first; - for (_DifferenceType __old = __extremum; __comp(__k, __old); - __old = __extremum) - { - __extremum.compare_exchange_weak(__old, __k); - } - } - } - }); - return __extremum != __initial_dist ? __first + __extremum : __last; -} - -//------------------------------------------------------------------------ -// parallel_or -//------------------------------------------------------------------------ -//! Return true if brick f[i,j) returns true for some subrange [i,j) of [first,last) -template <class _BackendTag, class _ExecutionPolicy, class _Index, class _Brick> -_LIBCPP_HIDE_FROM_ABI -bool __parallel_or(_BackendTag __tag, _ExecutionPolicy&& __exec, _Index __first, _Index __last, _Brick __f) { - std::atomic<bool> __found(false); - __par_backend::__parallel_for(__tag, std::forward<_ExecutionPolicy>(__exec), __first, __last, - [__f, &__found](_Index __i, _Index __j) - { - if (!__found.load(std::memory_order_relaxed) && __f(__i, __j)) - { - __found.store(true, std::memory_order_relaxed); - __par_backend::__cancel_execution(); - } - }); - return __found; -} - -} // namespace __internal -} // namespace __pstl - -#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17 - -#endif /* _PSTL_PARALLEL_IMPL_H */ |