| // -*- 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 __i; |
| // This will vectorize |
| for (__i = 0; __i < __block_size; ++__i) |
| { |
| if (__lane[__i]) |
| break; |
| } |
| return std::make_pair(__first1 + __i, __first2 + __i); |
| } |
| __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 __i = 0; __i < __block_size; ++__i) |
| { |
| __init = __binary_op(__init, __lane[__i]); |
| } |
| // destroyer |
| _PSTL_PRAGMA_SIMD |
| for (_Size __i = 0; __i < __block_size; ++__i) |
| { |
| __lane[__i].~_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 */ |
