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- // -*- C++ -*-
- //===-- unseq_backend_simd.h ----------------------------------------------===//
- //
- // 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_UNSEQ_BACKEND_SIMD_H
- #define _PSTL_UNSEQ_BACKEND_SIMD_H
- #include <type_traits>
- #include "utils.h"
- // This header defines the minimum set of vector routines required
- // to support parallel STL.
- namespace __pstl
- {
- namespace __unseq_backend
- {
- // Expect vector width up to 64 (or 512 bit)
- const std::size_t __lane_size = 64;
- template <class _Iterator, class _DifferenceType, class _Function>
- _Iterator
- __simd_walk_1(_Iterator __first, _DifferenceType __n, _Function __f) noexcept
- {
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- __f(__first[__i]);
- return __first + __n;
- }
- template <class _Iterator1, class _DifferenceType, class _Iterator2, class _Function>
- _Iterator2
- __simd_walk_2(_Iterator1 __first1, _DifferenceType __n, _Iterator2 __first2, _Function __f) noexcept
- {
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- __f(__first1[__i], __first2[__i]);
- return __first2 + __n;
- }
- template <class _Iterator1, class _DifferenceType, class _Iterator2, class _Iterator3, class _Function>
- _Iterator3
- __simd_walk_3(_Iterator1 __first1, _DifferenceType __n, _Iterator2 __first2, _Iterator3 __first3,
- _Function __f) noexcept
- {
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- __f(__first1[__i], __first2[__i], __first3[__i]);
- return __first3 + __n;
- }
- // TODO: check whether __simd_first() can be used here
- template <class _Index, class _DifferenceType, class _Pred>
- bool
- __simd_or(_Index __first, _DifferenceType __n, _Pred __pred) noexcept
- {
- #if _PSTL_EARLYEXIT_PRESENT
- _DifferenceType __i;
- _PSTL_PRAGMA_VECTOR_UNALIGNED
- _PSTL_PRAGMA_SIMD_EARLYEXIT
- for (__i = 0; __i < __n; ++__i)
- if (__pred(__first[__i]))
- break;
- return __i < __n;
- #else
- _DifferenceType __block_size = 4 < __n ? 4 : __n;
- const _Index __last = __first + __n;
- while (__last != __first)
- {
- int32_t __flag = 1;
- _PSTL_PRAGMA_SIMD_REDUCTION(& : __flag)
- for (_DifferenceType __i = 0; __i < __block_size; ++__i)
- if (__pred(*(__first + __i)))
- __flag = 0;
- if (!__flag)
- return true;
- __first += __block_size;
- if (__last - __first >= __block_size << 1)
- {
- // Double the block _Size. Any unnecessary iterations can be amortized against work done so far.
- __block_size <<= 1;
- }
- else
- {
- __block_size = __last - __first;
- }
- }
- return false;
- #endif
- }
- template <class _Index, class _DifferenceType, class _Compare>
- _Index
- __simd_first(_Index __first, _DifferenceType __begin, _DifferenceType __end, _Compare __comp) noexcept
- {
- #if _PSTL_EARLYEXIT_PRESENT
- _DifferenceType __i = __begin;
- _PSTL_PRAGMA_VECTOR_UNALIGNED // Do not generate peel loop part
- _PSTL_PRAGMA_SIMD_EARLYEXIT for (; __i < __end; ++__i)
- {
- if (__comp(__first, __i))
- {
- break;
- }
- }
- return __first + __i;
- #else
- // Experiments show good block sizes like this
- const _DifferenceType __block_size = 8;
- alignas(__lane_size) _DifferenceType __lane[__block_size] = {0};
- while (__end - __begin >= __block_size)
- {
- _DifferenceType __found = 0;
- _PSTL_PRAGMA_VECTOR_UNALIGNED // Do not generate peel loop part
- _PSTL_PRAGMA_SIMD_REDUCTION(|
- : __found) for (_DifferenceType __i = __begin; __i < __begin + __block_size;
- ++__i)
- {
- const _DifferenceType __t = __comp(__first, __i);
- __lane[__i - __begin] = __t;
- __found |= __t;
- }
- if (__found)
- {
- _DifferenceType __i;
- // This will vectorize
- for (__i = 0; __i < __block_size; ++__i)
- {
- if (__lane[__i])
- {
- break;
- }
- }
- return __first + __begin + __i;
- }
- __begin += __block_size;
- }
- //Keep remainder scalar
- while (__begin != __end)
- {
- if (__comp(__first, __begin))
- {
- return __first + __begin;
- }
- ++__begin;
- }
- return __first + __end;
- #endif //_PSTL_EARLYEXIT_PRESENT
- }
- template <class _Index1, class _DifferenceType, class _Index2, class _Pred>
- std::pair<_Index1, _Index2>
- __simd_first(_Index1 __first1, _DifferenceType __n, _Index2 __first2, _Pred __pred) noexcept
- {
- #if _PSTL_EARLYEXIT_PRESENT
- _DifferenceType __i = 0;
- _PSTL_PRAGMA_VECTOR_UNALIGNED
- _PSTL_PRAGMA_SIMD_EARLYEXIT
- for (; __i < __n; ++__i)
- if (__pred(__first1[__i], __first2[__i]))
- break;
- return std::make_pair(__first1 + __i, __first2 + __i);
- #else
- const _Index1 __last1 = __first1 + __n;
- const _Index2 __last2 = __first2 + __n;
- // Experiments show good block sizes like this
- const _DifferenceType __block_size = 8;
- alignas(__lane_size) _DifferenceType __lane[__block_size] = {0};
- while (__last1 - __first1 >= __block_size)
- {
- _DifferenceType __found = 0;
- _DifferenceType __i;
- _PSTL_PRAGMA_VECTOR_UNALIGNED // Do not generate peel loop part
- _PSTL_PRAGMA_SIMD_REDUCTION(|
- : __found) for (__i = 0; __i < __block_size; ++__i)
- {
- const _DifferenceType __t = __pred(__first1[__i], __first2[__i]);
- __lane[__i] = __t;
- __found |= __t;
- }
- if (__found)
- {
- _DifferenceType __i2;
- // This will vectorize
- for (__i2 = 0; __i2 < __block_size; ++__i2)
- {
- if (__lane[__i2])
- break;
- }
- return std::make_pair(__first1 + __i2, __first2 + __i2);
- }
- __first1 += __block_size;
- __first2 += __block_size;
- }
- //Keep remainder scalar
- for (; __last1 != __first1; ++__first1, ++__first2)
- if (__pred(*(__first1), *(__first2)))
- return std::make_pair(__first1, __first2);
- return std::make_pair(__last1, __last2);
- #endif //_PSTL_EARLYEXIT_PRESENT
- }
- template <class _Index, class _DifferenceType, class _Pred>
- _DifferenceType
- __simd_count(_Index __index, _DifferenceType __n, _Pred __pred) noexcept
- {
- _DifferenceType __count = 0;
- _PSTL_PRAGMA_SIMD_REDUCTION(+ : __count)
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- if (__pred(*(__index + __i)))
- ++__count;
- return __count;
- }
- template <class _InputIterator, class _DifferenceType, class _OutputIterator, class _BinaryPredicate>
- _OutputIterator
- __simd_unique_copy(_InputIterator __first, _DifferenceType __n, _OutputIterator __result,
- _BinaryPredicate __pred) noexcept
- {
- if (__n == 0)
- return __result;
- _DifferenceType __cnt = 1;
- __result[0] = __first[0];
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 1; __i < __n; ++__i)
- {
- _PSTL_PRAGMA_SIMD_ORDERED_MONOTONIC(__cnt : 1)
- if (!__pred(__first[__i], __first[__i - 1]))
- {
- __result[__cnt] = __first[__i];
- ++__cnt;
- }
- }
- return __result + __cnt;
- }
- template <class _InputIterator, class _DifferenceType, class _OutputIterator, class _Assigner>
- _OutputIterator
- __simd_assign(_InputIterator __first, _DifferenceType __n, _OutputIterator __result, _Assigner __assigner) noexcept
- {
- _PSTL_USE_NONTEMPORAL_STORES_IF_ALLOWED
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- __assigner(__first + __i, __result + __i);
- return __result + __n;
- }
- template <class _InputIterator, class _DifferenceType, class _OutputIterator, class _UnaryPredicate>
- _OutputIterator
- __simd_copy_if(_InputIterator __first, _DifferenceType __n, _OutputIterator __result, _UnaryPredicate __pred) noexcept
- {
- _DifferenceType __cnt = 0;
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- {
- _PSTL_PRAGMA_SIMD_ORDERED_MONOTONIC(__cnt : 1)
- if (__pred(__first[__i]))
- {
- __result[__cnt] = __first[__i];
- ++__cnt;
- }
- }
- return __result + __cnt;
- }
- template <class _InputIterator, class _DifferenceType, class _BinaryPredicate>
- _DifferenceType
- __simd_calc_mask_2(_InputIterator __first, _DifferenceType __n, bool* __mask, _BinaryPredicate __pred) noexcept
- {
- _DifferenceType __count = 0;
- _PSTL_PRAGMA_SIMD_REDUCTION(+ : __count)
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- {
- __mask[__i] = !__pred(__first[__i], __first[__i - 1]);
- __count += __mask[__i];
- }
- return __count;
- }
- template <class _InputIterator, class _DifferenceType, class _UnaryPredicate>
- _DifferenceType
- __simd_calc_mask_1(_InputIterator __first, _DifferenceType __n, bool* __mask, _UnaryPredicate __pred) noexcept
- {
- _DifferenceType __count = 0;
- _PSTL_PRAGMA_SIMD_REDUCTION(+ : __count)
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- {
- __mask[__i] = __pred(__first[__i]);
- __count += __mask[__i];
- }
- return __count;
- }
- template <class _InputIterator, class _DifferenceType, class _OutputIterator, class _Assigner>
- void
- __simd_copy_by_mask(_InputIterator __first, _DifferenceType __n, _OutputIterator __result, bool* __mask,
- _Assigner __assigner) noexcept
- {
- _DifferenceType __cnt = 0;
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- {
- if (__mask[__i])
- {
- _PSTL_PRAGMA_SIMD_ORDERED_MONOTONIC(__cnt : 1)
- {
- __assigner(__first + __i, __result + __cnt);
- ++__cnt;
- }
- }
- }
- }
- template <class _InputIterator, class _DifferenceType, class _OutputIterator1, class _OutputIterator2>
- void
- __simd_partition_by_mask(_InputIterator __first, _DifferenceType __n, _OutputIterator1 __out_true,
- _OutputIterator2 __out_false, bool* __mask) noexcept
- {
- _DifferenceType __cnt_true = 0, __cnt_false = 0;
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- {
- _PSTL_PRAGMA_SIMD_ORDERED_MONOTONIC_2ARGS(__cnt_true : 1, __cnt_false : 1)
- if (__mask[__i])
- {
- __out_true[__cnt_true] = __first[__i];
- ++__cnt_true;
- }
- else
- {
- __out_false[__cnt_false] = __first[__i];
- ++__cnt_false;
- }
- }
- }
- template <class _Index, class _DifferenceType, class _Tp>
- _Index
- __simd_fill_n(_Index __first, _DifferenceType __n, const _Tp& __value) noexcept
- {
- _PSTL_USE_NONTEMPORAL_STORES_IF_ALLOWED
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- __first[__i] = __value;
- return __first + __n;
- }
- template <class _Index, class _DifferenceType, class _Generator>
- _Index
- __simd_generate_n(_Index __first, _DifferenceType __size, _Generator __g) noexcept
- {
- _PSTL_USE_NONTEMPORAL_STORES_IF_ALLOWED
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __size; ++__i)
- __first[__i] = __g();
- return __first + __size;
- }
- template <class _Index, class _BinaryPredicate>
- _Index
- __simd_adjacent_find(_Index __first, _Index __last, _BinaryPredicate __pred, bool __or_semantic) noexcept
- {
- if (__last - __first < 2)
- return __last;
- typedef typename std::iterator_traits<_Index>::difference_type _DifferenceType;
- _DifferenceType __i = 0;
- #if _PSTL_EARLYEXIT_PRESENT
- //Some compiler versions fail to compile the following loop when iterators are used. Indices are used instead
- const _DifferenceType __n = __last - __first - 1;
- _PSTL_PRAGMA_VECTOR_UNALIGNED
- _PSTL_PRAGMA_SIMD_EARLYEXIT
- for (; __i < __n; ++__i)
- if (__pred(__first[__i], __first[__i + 1]))
- break;
- return __i < __n ? __first + __i : __last;
- #else
- // Experiments show good block sizes like this
- //TODO: to consider tuning block_size for various data types
- const _DifferenceType __block_size = 8;
- alignas(__lane_size) _DifferenceType __lane[__block_size] = {0};
- while (__last - __first >= __block_size)
- {
- _DifferenceType __found = 0;
- _PSTL_PRAGMA_VECTOR_UNALIGNED // Do not generate peel loop part
- _PSTL_PRAGMA_SIMD_REDUCTION(|
- : __found) for (__i = 0; __i < __block_size - 1; ++__i)
- {
- //TODO: to improve SIMD vectorization
- const _DifferenceType __t = __pred(*(__first + __i), *(__first + __i + 1));
- __lane[__i] = __t;
- __found |= __t;
- }
- //Process a pair of elements on a boundary of a data block
- if (__first + __block_size < __last && __pred(*(__first + __i), *(__first + __i + 1)))
- __lane[__i] = __found = 1;
- if (__found)
- {
- if (__or_semantic)
- return __first;
- // This will vectorize
- for (__i = 0; __i < __block_size; ++__i)
- if (__lane[__i])
- break;
- return __first + __i; //As far as found is true a __result (__lane[__i] is true) is guaranteed
- }
- __first += __block_size;
- }
- //Process the rest elements
- for (; __last - __first > 1; ++__first)
- if (__pred(*__first, *(__first + 1)))
- return __first;
- return __last;
- #endif
- }
- // It was created to reduce the code inside std::enable_if
- template <typename _Tp, typename _BinaryOperation>
- using is_arithmetic_plus = std::integral_constant<bool, std::is_arithmetic<_Tp>::value &&
- std::is_same<_BinaryOperation, std::plus<_Tp>>::value>;
- template <typename _DifferenceType, typename _Tp, typename _BinaryOperation, typename _UnaryOperation>
- typename std::enable_if<is_arithmetic_plus<_Tp, _BinaryOperation>::value, _Tp>::type
- __simd_transform_reduce(_DifferenceType __n, _Tp __init, _BinaryOperation, _UnaryOperation __f) noexcept
- {
- _PSTL_PRAGMA_SIMD_REDUCTION(+ : __init)
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- __init += __f(__i);
- return __init;
- }
- template <typename _Size, typename _Tp, typename _BinaryOperation, typename _UnaryOperation>
- typename std::enable_if<!is_arithmetic_plus<_Tp, _BinaryOperation>::value, _Tp>::type
- __simd_transform_reduce(_Size __n, _Tp __init, _BinaryOperation __binary_op, _UnaryOperation __f) noexcept
- {
- const _Size __block_size = __lane_size / sizeof(_Tp);
- if (__n > 2 * __block_size && __block_size > 1)
- {
- alignas(__lane_size) char __lane_[__lane_size];
- _Tp* __lane = reinterpret_cast<_Tp*>(__lane_);
- // initializer
- _PSTL_PRAGMA_SIMD
- for (_Size __i = 0; __i < __block_size; ++__i)
- {
- ::new (__lane + __i) _Tp(__binary_op(__f(__i), __f(__block_size + __i)));
- }
- // main loop
- _Size __i = 2 * __block_size;
- const _Size last_iteration = __block_size * (__n / __block_size);
- for (; __i < last_iteration; __i += __block_size)
- {
- _PSTL_PRAGMA_SIMD
- for (_Size __j = 0; __j < __block_size; ++__j)
- {
- __lane[__j] = __binary_op(__lane[__j], __f(__i + __j));
- }
- }
- // remainder
- _PSTL_PRAGMA_SIMD
- for (_Size __j = 0; __j < __n - last_iteration; ++__j)
- {
- __lane[__j] = __binary_op(__lane[__j], __f(last_iteration + __j));
- }
- // combiner
- for (_Size __j = 0; __j < __block_size; ++__j)
- {
- __init = __binary_op(__init, __lane[__j]);
- }
- // destroyer
- _PSTL_PRAGMA_SIMD
- for (_Size __j = 0; __j < __block_size; ++__j)
- {
- __lane[__j].~_Tp();
- }
- }
- else
- {
- for (_Size __i = 0; __i < __n; ++__i)
- {
- __init = __binary_op(__init, __f(__i));
- }
- }
- return __init;
- }
- // Exclusive scan for "+" and arithmetic types
- template <class _InputIterator, class _Size, class _OutputIterator, class _UnaryOperation, class _Tp,
- class _BinaryOperation>
- typename std::enable_if<is_arithmetic_plus<_Tp, _BinaryOperation>::value, std::pair<_OutputIterator, _Tp>>::type
- __simd_scan(_InputIterator __first, _Size __n, _OutputIterator __result, _UnaryOperation __unary_op, _Tp __init,
- _BinaryOperation, /*Inclusive*/ std::false_type)
- {
- _PSTL_PRAGMA_SIMD_SCAN(+ : __init)
- for (_Size __i = 0; __i < __n; ++__i)
- {
- __result[__i] = __init;
- _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(__init)
- __init += __unary_op(__first[__i]);
- }
- return std::make_pair(__result + __n, __init);
- }
- // As soon as we cannot call __binary_op in "combiner" we create a wrapper over _Tp to encapsulate __binary_op
- template <typename _Tp, typename _BinaryOp>
- struct _Combiner
- {
- _Tp __value;
- _BinaryOp* __bin_op; // Here is a pointer to function because of default ctor
- _Combiner() : __value{}, __bin_op(nullptr) {}
- _Combiner(const _Tp& value, const _BinaryOp* bin_op) : __value(value), __bin_op(const_cast<_BinaryOp*>(bin_op)) {}
- _Combiner(const _Combiner& __obj) : __value{}, __bin_op(__obj.__bin_op) {}
- void
- operator()(const _Combiner& __obj)
- {
- __value = (*__bin_op)(__value, __obj.__value);
- }
- };
- // Exclusive scan for other binary operations and types
- template <class _InputIterator, class _Size, class _OutputIterator, class _UnaryOperation, class _Tp,
- class _BinaryOperation>
- typename std::enable_if<!is_arithmetic_plus<_Tp, _BinaryOperation>::value, std::pair<_OutputIterator, _Tp>>::type
- __simd_scan(_InputIterator __first, _Size __n, _OutputIterator __result, _UnaryOperation __unary_op, _Tp __init,
- _BinaryOperation __binary_op, /*Inclusive*/ std::false_type)
- {
- typedef _Combiner<_Tp, _BinaryOperation> _CombinerType;
- _CombinerType __init_{__init, &__binary_op};
- _PSTL_PRAGMA_DECLARE_REDUCTION(__bin_op, _CombinerType)
- _PSTL_PRAGMA_SIMD_SCAN(__bin_op : __init_)
- for (_Size __i = 0; __i < __n; ++__i)
- {
- __result[__i] = __init_.__value;
- _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(__init_)
- _PSTL_PRAGMA_FORCEINLINE
- __init_.__value = __binary_op(__init_.__value, __unary_op(__first[__i]));
- }
- return std::make_pair(__result + __n, __init_.__value);
- }
- // Inclusive scan for "+" and arithmetic types
- template <class _InputIterator, class _Size, class _OutputIterator, class _UnaryOperation, class _Tp,
- class _BinaryOperation>
- typename std::enable_if<is_arithmetic_plus<_Tp, _BinaryOperation>::value, std::pair<_OutputIterator, _Tp>>::type
- __simd_scan(_InputIterator __first, _Size __n, _OutputIterator __result, _UnaryOperation __unary_op, _Tp __init,
- _BinaryOperation, /*Inclusive*/ std::true_type)
- {
- _PSTL_PRAGMA_SIMD_SCAN(+ : __init)
- for (_Size __i = 0; __i < __n; ++__i)
- {
- __init += __unary_op(__first[__i]);
- _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(__init)
- __result[__i] = __init;
- }
- return std::make_pair(__result + __n, __init);
- }
- // Inclusive scan for other binary operations and types
- template <class _InputIterator, class _Size, class _OutputIterator, class _UnaryOperation, class _Tp,
- class _BinaryOperation>
- typename std::enable_if<!is_arithmetic_plus<_Tp, _BinaryOperation>::value, std::pair<_OutputIterator, _Tp>>::type
- __simd_scan(_InputIterator __first, _Size __n, _OutputIterator __result, _UnaryOperation __unary_op, _Tp __init,
- _BinaryOperation __binary_op, std::true_type)
- {
- typedef _Combiner<_Tp, _BinaryOperation> _CombinerType;
- _CombinerType __init_{__init, &__binary_op};
- _PSTL_PRAGMA_DECLARE_REDUCTION(__bin_op, _CombinerType)
- _PSTL_PRAGMA_SIMD_SCAN(__bin_op : __init_)
- for (_Size __i = 0; __i < __n; ++__i)
- {
- _PSTL_PRAGMA_FORCEINLINE
- __init_.__value = __binary_op(__init_.__value, __unary_op(__first[__i]));
- _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(__init_)
- __result[__i] = __init_.__value;
- }
- return std::make_pair(__result + __n, __init_.__value);
- }
- // [restriction] - std::iterator_traits<_ForwardIterator>::value_type should be DefaultConstructible.
- // complexity [violation] - We will have at most (__n-1 + number_of_lanes) comparisons instead of at most __n-1.
- template <typename _ForwardIterator, typename _Size, typename _Compare>
- _ForwardIterator
- __simd_min_element(_ForwardIterator __first, _Size __n, _Compare __comp) noexcept
- {
- if (__n == 0)
- {
- return __first;
- }
- typedef typename std::iterator_traits<_ForwardIterator>::value_type _ValueType;
- struct _ComplexType
- {
- _ValueType __min_val;
- _Size __min_ind;
- _Compare* __min_comp;
- _ComplexType() : __min_val{}, __min_ind{}, __min_comp(nullptr) {}
- _ComplexType(const _ValueType& val, const _Compare* comp)
- : __min_val(val), __min_ind(0), __min_comp(const_cast<_Compare*>(comp))
- {
- }
- _ComplexType(const _ComplexType& __obj)
- : __min_val(__obj.__min_val), __min_ind(__obj.__min_ind), __min_comp(__obj.__min_comp)
- {
- }
- _PSTL_PRAGMA_DECLARE_SIMD
- void
- operator()(const _ComplexType& __obj)
- {
- if (!(*__min_comp)(__min_val, __obj.__min_val) &&
- ((*__min_comp)(__obj.__min_val, __min_val) || __obj.__min_ind - __min_ind < 0))
- {
- __min_val = __obj.__min_val;
- __min_ind = __obj.__min_ind;
- }
- }
- };
- _ComplexType __init{*__first, &__comp};
- _PSTL_PRAGMA_DECLARE_REDUCTION(__min_func, _ComplexType)
- _PSTL_PRAGMA_SIMD_REDUCTION(__min_func : __init)
- for (_Size __i = 1; __i < __n; ++__i)
- {
- const _ValueType __min_val = __init.__min_val;
- const _ValueType __current = __first[__i];
- if (__comp(__current, __min_val))
- {
- __init.__min_val = __current;
- __init.__min_ind = __i;
- }
- }
- return __first + __init.__min_ind;
- }
- // [restriction] - std::iterator_traits<_ForwardIterator>::value_type should be DefaultConstructible.
- // complexity [violation] - We will have at most (2*(__n-1) + 4*number_of_lanes) comparisons instead of at most [1.5*(__n-1)].
- template <typename _ForwardIterator, typename _Size, typename _Compare>
- std::pair<_ForwardIterator, _ForwardIterator>
- __simd_minmax_element(_ForwardIterator __first, _Size __n, _Compare __comp) noexcept
- {
- if (__n == 0)
- {
- return std::make_pair(__first, __first);
- }
- typedef typename std::iterator_traits<_ForwardIterator>::value_type _ValueType;
- struct _ComplexType
- {
- _ValueType __min_val;
- _ValueType __max_val;
- _Size __min_ind;
- _Size __max_ind;
- _Compare* __minmax_comp;
- _ComplexType() : __min_val{}, __max_val{}, __min_ind{}, __max_ind{}, __minmax_comp(nullptr) {}
- _ComplexType(const _ValueType& min_val, const _ValueType& max_val, const _Compare* comp)
- : __min_val(min_val), __max_val(max_val), __min_ind(0), __max_ind(0),
- __minmax_comp(const_cast<_Compare*>(comp))
- {
- }
- _ComplexType(const _ComplexType& __obj)
- : __min_val(__obj.__min_val), __max_val(__obj.__max_val), __min_ind(__obj.__min_ind),
- __max_ind(__obj.__max_ind), __minmax_comp(__obj.__minmax_comp)
- {
- }
- void
- operator()(const _ComplexType& __obj)
- {
- // min
- if ((*__minmax_comp)(__obj.__min_val, __min_val))
- {
- __min_val = __obj.__min_val;
- __min_ind = __obj.__min_ind;
- }
- else if (!(*__minmax_comp)(__min_val, __obj.__min_val))
- {
- __min_val = __obj.__min_val;
- __min_ind = (__min_ind - __obj.__min_ind < 0) ? __min_ind : __obj.__min_ind;
- }
- // max
- if ((*__minmax_comp)(__max_val, __obj.__max_val))
- {
- __max_val = __obj.__max_val;
- __max_ind = __obj.__max_ind;
- }
- else if (!(*__minmax_comp)(__obj.__max_val, __max_val))
- {
- __max_val = __obj.__max_val;
- __max_ind = (__max_ind - __obj.__max_ind < 0) ? __obj.__max_ind : __max_ind;
- }
- }
- };
- _ComplexType __init{*__first, *__first, &__comp};
- _PSTL_PRAGMA_DECLARE_REDUCTION(__min_func, _ComplexType);
- _PSTL_PRAGMA_SIMD_REDUCTION(__min_func : __init)
- for (_Size __i = 1; __i < __n; ++__i)
- {
- auto __min_val = __init.__min_val;
- auto __max_val = __init.__max_val;
- auto __current = __first + __i;
- if (__comp(*__current, __min_val))
- {
- __init.__min_val = *__current;
- __init.__min_ind = __i;
- }
- else if (!__comp(*__current, __max_val))
- {
- __init.__max_val = *__current;
- __init.__max_ind = __i;
- }
- }
- return std::make_pair(__first + __init.__min_ind, __first + __init.__max_ind);
- }
- template <class _InputIterator, class _DifferenceType, class _OutputIterator1, class _OutputIterator2,
- class _UnaryPredicate>
- std::pair<_OutputIterator1, _OutputIterator2>
- __simd_partition_copy(_InputIterator __first, _DifferenceType __n, _OutputIterator1 __out_true,
- _OutputIterator2 __out_false, _UnaryPredicate __pred) noexcept
- {
- _DifferenceType __cnt_true = 0, __cnt_false = 0;
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 0; __i < __n; ++__i)
- {
- _PSTL_PRAGMA_SIMD_ORDERED_MONOTONIC_2ARGS(__cnt_true : 1, __cnt_false : 1)
- if (__pred(__first[__i]))
- {
- __out_true[__cnt_true] = __first[__i];
- ++__cnt_true;
- }
- else
- {
- __out_false[__cnt_false] = __first[__i];
- ++__cnt_false;
- }
- }
- return std::make_pair(__out_true + __cnt_true, __out_false + __cnt_false);
- }
- template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
- _ForwardIterator1
- __simd_find_first_of(_ForwardIterator1 __first, _ForwardIterator1 __last, _ForwardIterator2 __s_first,
- _ForwardIterator2 __s_last, _BinaryPredicate __pred) noexcept
- {
- typedef typename std::iterator_traits<_ForwardIterator1>::difference_type _DifferencType;
- const _DifferencType __n1 = __last - __first;
- const _DifferencType __n2 = __s_last - __s_first;
- if (__n1 == 0 || __n2 == 0)
- {
- return __last; // according to the standard
- }
- // Common case
- // If first sequence larger than second then we'll run simd_first with parameters of first sequence.
- // Otherwise, vice versa.
- if (__n1 < __n2)
- {
- for (; __first != __last; ++__first)
- {
- if (__unseq_backend::__simd_or(
- __s_first, __n2,
- __internal::__equal_value_by_pred<decltype(*__first), _BinaryPredicate>(*__first, __pred)))
- {
- return __first;
- }
- }
- }
- else
- {
- for (; __s_first != __s_last; ++__s_first)
- {
- const auto __result = __unseq_backend::__simd_first(
- __first, _DifferencType(0), __n1, [__s_first, &__pred](_ForwardIterator1 __it, _DifferencType __i) {
- return __pred(__it[__i], *__s_first);
- });
- if (__result != __last)
- {
- return __result;
- }
- }
- }
- return __last;
- }
- template <class _RandomAccessIterator, class _DifferenceType, class _UnaryPredicate>
- _RandomAccessIterator
- __simd_remove_if(_RandomAccessIterator __first, _DifferenceType __n, _UnaryPredicate __pred) noexcept
- {
- // find first element we need to remove
- auto __current = __unseq_backend::__simd_first(
- __first, _DifferenceType(0), __n,
- [&__pred](_RandomAccessIterator __it, _DifferenceType __i) { return __pred(__it[__i]); });
- __n -= __current - __first;
- // if we have in sequence only one element that pred(__current[1]) != false we can exit the function
- if (__n < 2)
- {
- return __current;
- }
- _DifferenceType __cnt = 0;
- _PSTL_PRAGMA_SIMD
- for (_DifferenceType __i = 1; __i < __n; ++__i)
- {
- _PSTL_PRAGMA_SIMD_ORDERED_MONOTONIC(__cnt : 1)
- if (!__pred(__current[__i]))
- {
- __current[__cnt] = std::move(__current[__i]);
- ++__cnt;
- }
- }
- return __current + __cnt;
- }
- } // namespace __unseq_backend
- } // namespace __pstl
- #endif /* _PSTL_UNSEQ_BACKEND_SIMD_H */
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