// -*- C++ -*-
//===-- numeric_impl.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_NUMERIC_IMPL_H
#define _PSTL_NUMERIC_IMPL_H
#include <iterator>
#include <type_traits>
#include <numeric>
#include "parallel_backend.h"
#include "pstl_config.h"
#include "execution_impl.h"
#include "unseq_backend_simd.h"
#include "algorithm_fwd.h"
namespace __pstl
{
namespace __internal
{
//------------------------------------------------------------------------
// transform_reduce (version with two binary functions, according to draft N4659)
//------------------------------------------------------------------------
template <class _ForwardIterator1, class _ForwardIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
_Tp
__brick_transform_reduce(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _Tp __init,
_BinaryOperation1 __binary_op1, _BinaryOperation2 __binary_op2,
/*is_vector=*/std::false_type) noexcept
{
return std::inner_product(__first1, __last1, __first2, __init, __binary_op1, __binary_op2);
}
template <class _ForwardIterator1, class _ForwardIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
_Tp
__brick_transform_reduce(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2, _Tp __init,
_BinaryOperation1 __binary_op1, _BinaryOperation2 __binary_op2,
/*is_vector=*/std::true_type) noexcept
{
typedef typename std::iterator_traits<_ForwardIterator1>::difference_type _DifferenceType;
return __unseq_backend::__simd_transform_reduce(
__last1 - __first1, __init, __binary_op1,
[=, &__binary_op2](_DifferenceType __i) { return __binary_op2(__first1[__i], __first2[__i]); });
}
template <class _ExecutionPolicy, class _ForwardIterator1, class _ForwardIterator2, class _Tp, class _BinaryOperation1,
class _BinaryOperation2, class _IsVector>
_Tp
__pattern_transform_reduce(_ExecutionPolicy&&, _ForwardIterator1 __first1, _ForwardIterator1 __last1,
_ForwardIterator2 __first2, _Tp __init, _BinaryOperation1 __binary_op1,
_BinaryOperation2 __binary_op2, _IsVector __is_vector,
/*is_parallel=*/std::false_type) noexcept
{
return __brick_transform_reduce(__first1, __last1, __first2, __init, __binary_op1, __binary_op2, __is_vector);
}
template <class _ExecutionPolicy, class _RandomAccessIterator1, class _RandomAccessIterator2, class _Tp,
class _BinaryOperation1, class _BinaryOperation2, class _IsVector>
_Tp
__pattern_transform_reduce(_ExecutionPolicy&& __exec, _RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
_RandomAccessIterator2 __first2, _Tp __init, _BinaryOperation1 __binary_op1,
_BinaryOperation2 __binary_op2, _IsVector __is_vector, /*is_parallel=*/std::true_type)
{
return __internal::__except_handler([&]() {
return __par_backend::__parallel_transform_reduce(
std::forward<_ExecutionPolicy>(__exec), __first1, __last1,
[__first1, __first2, __binary_op2](_RandomAccessIterator1 __i) mutable {
return __binary_op2(*__i, *(__first2 + (__i - __first1)));
},
__init,
__binary_op1, // Combine
[__first1, __first2, __binary_op1, __binary_op2,
__is_vector](_RandomAccessIterator1 __i, _RandomAccessIterator1 __j, _Tp __init) -> _Tp {
return __internal::__brick_transform_reduce(__i, __j, __first2 + (__i - __first1), __init, __binary_op1,
__binary_op2, __is_vector);
});
});
}
//------------------------------------------------------------------------
// transform_reduce (version with unary and binary functions)
//------------------------------------------------------------------------
template <class _ForwardIterator, class _Tp, class _BinaryOperation, class _UnaryOperation>
_Tp
__brick_transform_reduce(_ForwardIterator __first, _ForwardIterator __last, _Tp __init, _BinaryOperation __binary_op,
_UnaryOperation __unary_op, /*is_vector=*/std::false_type) noexcept
{
for (; __first != __last; ++__first)
{
__init = __binary_op(__init, __unary_op(*__first));
}
return __init;
}
template <class _ForwardIterator, class _Tp, class _UnaryOperation, class _BinaryOperation>
_Tp
__brick_transform_reduce(_ForwardIterator __first, _ForwardIterator __last, _Tp __init, _BinaryOperation __binary_op,
_UnaryOperation __unary_op, /*is_vector=*/std::true_type) noexcept
{
typedef typename std::iterator_traits<_ForwardIterator>::difference_type _DifferenceType;
return __unseq_backend::__simd_transform_reduce(
__last - __first, __init, __binary_op,
[=, &__unary_op](_DifferenceType __i) { return __unary_op(__first[__i]); });
}
template <class _ExecutionPolicy, class _ForwardIterator, class _Tp, class _BinaryOperation, class _UnaryOperation,
class _IsVector>
_Tp
__pattern_transform_reduce(_ExecutionPolicy&&, _ForwardIterator __first, _ForwardIterator __last, _Tp __init,
_BinaryOperation __binary_op, _UnaryOperation __unary_op, _IsVector __is_vector,
/*is_parallel=*/std::false_type) noexcept
{
return __internal::__brick_transform_reduce(__first, __last, __init, __binary_op, __unary_op, __is_vector);
}
template <class _ExecutionPolicy, class _ForwardIterator, class _Tp, class _BinaryOperation, class _UnaryOperation,
class _IsVector>
_Tp
__pattern_transform_reduce(_ExecutionPolicy&& __exec, _ForwardIterator __first, _ForwardIterator __last, _Tp __init,
_BinaryOperation __binary_op, _UnaryOperation __unary_op, _IsVector __is_vector,
/*is_parallel=*/std::true_type)
{
return __internal::__except_handler([&]() {
return __par_backend::__parallel_transform_reduce(
std::forward<_ExecutionPolicy>(__exec), __first, __last,
[__unary_op](_ForwardIterator __i) mutable { return __unary_op(*__i); }, __init, __binary_op,
[__unary_op, __binary_op, __is_vector](_ForwardIterator __i, _ForwardIterator __j, _Tp __init) {
return __internal::__brick_transform_reduce(__i, __j, __init, __binary_op, __unary_op, __is_vector);
});
});
}
//------------------------------------------------------------------------
// transform_exclusive_scan
//
// walk3 evaluates f(x,y,z) for (x,y,z) drawn from [first1,last1), [first2,...), [first3,...)
//------------------------------------------------------------------------
// Exclusive form
template <class _ForwardIterator, class _OutputIterator, class _UnaryOperation, class _Tp, class _BinaryOperation>
std::pair<_OutputIterator, _Tp>
__brick_transform_scan(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result,
_UnaryOperation __unary_op, _Tp __init, _BinaryOperation __binary_op,
/*Inclusive*/ std::false_type, /*is_vector=*/std::false_type) noexcept
{
for (; __first != __last; ++__first, ++__result)
{
*__result = __init;
_PSTL_PRAGMA_FORCEINLINE
__init = __binary_op(__init, __unary_op(*__first));
}
return std::make_pair(__result, __init);
}
// Inclusive form
template <class _ForwardIterator, class _OutputIterator, class _UnaryOperation, class _Tp, class _BinaryOperation>
std::pair<_OutputIterator, _Tp>
__brick_transform_scan(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result,
_UnaryOperation __unary_op, _Tp __init, _BinaryOperation __binary_op,
/*Inclusive*/ std::true_type, /*is_vector=*/std::false_type) noexcept
{
for (; __first != __last; ++__first, ++__result)
{
_PSTL_PRAGMA_FORCEINLINE
__init = __binary_op(__init, __unary_op(*__first));
*__result = __init;
}
return std::make_pair(__result, __init);
}
// type is arithmetic and binary operation is a user defined operation.
template <typename _Tp, typename _BinaryOperation>
using is_arithmetic_udop = std::integral_constant<bool, std::is_arithmetic<_Tp>::value &&
!std::is_same<_BinaryOperation, std::plus<_Tp>>::value>;
// [restriction] - T shall be DefaultConstructible.
// [violation] - default ctor of T shall set the identity value for binary_op.
template <class _ForwardIterator, class _OutputIterator, class _UnaryOperation, class _Tp, class _BinaryOperation,
class _Inclusive>
typename std::enable_if<!is_arithmetic_udop<_Tp, _BinaryOperation>::value, std::pair<_OutputIterator, _Tp>>::type
__brick_transform_scan(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result,
_UnaryOperation __unary_op, _Tp __init, _BinaryOperation __binary_op, _Inclusive,
/*is_vector=*/std::true_type) noexcept
{
#if (_PSTL_UDS_PRESENT)
return __unseq_backend::__simd_scan(__first, __last - __first, __result, __unary_op, __init, __binary_op,
_Inclusive());
#else
// We need to call serial brick here to call function for inclusive and exclusive scan that depends on _Inclusive() value
return __internal::__brick_transform_scan(__first, __last, __result, __unary_op, __init, __binary_op, _Inclusive(),
/*is_vector=*/std::false_type());
#endif
}
template <class _ForwardIterator, class _OutputIterator, class _UnaryOperation, class _Tp, class _BinaryOperation,
class _Inclusive>
typename std::enable_if<is_arithmetic_udop<_Tp, _BinaryOperation>::value, std::pair<_OutputIterator, _Tp>>::type
__brick_transform_scan(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result,
_UnaryOperation __unary_op, _Tp __init, _BinaryOperation __binary_op, _Inclusive,
/*is_vector=*/std::true_type) noexcept
{
return __internal::__brick_transform_scan(__first, __last, __result, __unary_op, __init, __binary_op, _Inclusive(),
/*is_vector=*/std::false_type());
}
template <class _ExecutionPolicy, class _ForwardIterator, class _OutputIterator, class _UnaryOperation, class _Tp,
class _BinaryOperation, class _Inclusive, class _IsVector>
_OutputIterator
__pattern_transform_scan(_ExecutionPolicy&&, _ForwardIterator __first, _ForwardIterator __last,
_OutputIterator __result, _UnaryOperation __unary_op, _Tp __init, _BinaryOperation __binary_op,
_Inclusive, _IsVector __is_vector, /*is_parallel=*/std::false_type) noexcept
{
return __internal::__brick_transform_scan(__first, __last, __result, __unary_op, __init, __binary_op, _Inclusive(),
__is_vector)
.first;
}
template <class _ExecutionPolicy, class _RandomAccessIterator, class _OutputIterator, class _UnaryOperation, class _Tp,
class _BinaryOperation, class _Inclusive, class _IsVector>
typename std::enable_if<!std::is_floating_point<_Tp>::value, _OutputIterator>::type
__pattern_transform_scan(_ExecutionPolicy&& __exec, _RandomAccessIterator __first, _RandomAccessIterator __last,
_OutputIterator __result, _UnaryOperation __unary_op, _Tp __init, _BinaryOperation __binary_op,
_Inclusive, _IsVector __is_vector, /*is_parallel=*/std::true_type)
{
typedef typename std::iterator_traits<_RandomAccessIterator>::difference_type _DifferenceType;
return __internal::__except_handler([&]() {
__par_backend::__parallel_transform_scan(
std::forward<_ExecutionPolicy>(__exec), __last - __first,
[__first, __unary_op](_DifferenceType __i) mutable { return __unary_op(__first[__i]); }, __init,
__binary_op,
[__first, __unary_op, __binary_op](_DifferenceType __i, _DifferenceType __j, _Tp __init) {
// Execute serial __brick_transform_reduce, due to the explicit SIMD vectorization (reduction) requires a commutative operation for the guarantee of correct scan.
return __internal::__brick_transform_reduce(__first + __i, __first + __j, __init, __binary_op,
__unary_op,
/*__is_vector*/ std::false_type());
},
[__first, __unary_op, __binary_op, __result, __is_vector](_DifferenceType __i, _DifferenceType __j,
_Tp __init) {
return __internal::__brick_transform_scan(__first + __i, __first + __j, __result + __i, __unary_op,
__init, __binary_op, _Inclusive(), __is_vector)
.second;
});
return __result + (__last - __first);
});
}
template <class _ExecutionPolicy, class _RandomAccessIterator, class _OutputIterator, class _UnaryOperation, class _Tp,
class _BinaryOperation, class _Inclusive, class _IsVector>
typename std::enable_if<std::is_floating_point<_Tp>::value, _OutputIterator>::type
__pattern_transform_scan(_ExecutionPolicy&& __exec, _RandomAccessIterator __first, _RandomAccessIterator __last,
_OutputIterator __result, _UnaryOperation __unary_op, _Tp __init, _BinaryOperation __binary_op,
_Inclusive, _IsVector __is_vector, /*is_parallel=*/std::true_type)
{
typedef typename std::iterator_traits<_RandomAccessIterator>::difference_type _DifferenceType;
_DifferenceType __n = __last - __first;
if (__n <= 0)
{
return __result;
}
return __internal::__except_handler([&]() {
__par_backend::__parallel_strict_scan(
std::forward<_ExecutionPolicy>(__exec), __n, __init,
[__first, __unary_op, __binary_op, __result, __is_vector](_DifferenceType __i, _DifferenceType __len) {
return __internal::__brick_transform_scan(__first + __i, __first + (__i + __len), __result + __i,
__unary_op, _Tp{}, __binary_op, _Inclusive(), __is_vector)
.second;
},
__binary_op,
[__result, &__binary_op](_DifferenceType __i, _DifferenceType __len, _Tp __initial) {
return *(std::transform(__result + __i, __result + __i + __len, __result + __i,
[&__initial, &__binary_op](const _Tp& __x) {
_PSTL_PRAGMA_FORCEINLINE
return __binary_op(__initial, __x);
}) -
1);
},
[](_Tp __res) {});
return __result + (__last - __first);
});
}
//------------------------------------------------------------------------
// adjacent_difference
//------------------------------------------------------------------------
template <class _ForwardIterator, class _OutputIterator, class _BinaryOperation>
_OutputIterator
__brick_adjacent_difference(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __d_first,
_BinaryOperation __op, /*is_vector*/ std::false_type) noexcept
{
return std::adjacent_difference(__first, __last, __d_first, __op);
}
template <class _ForwardIterator1, class _ForwardIterator2, class BinaryOperation>
_ForwardIterator2
__brick_adjacent_difference(_ForwardIterator1 __first, _ForwardIterator1 __last, _ForwardIterator2 __d_first,
BinaryOperation __op, /*is_vector=*/std::true_type) noexcept
{
_PSTL_ASSERT(__first != __last);
typedef typename std::iterator_traits<_ForwardIterator1>::reference _ReferenceType1;
typedef typename std::iterator_traits<_ForwardIterator2>::reference _ReferenceType2;
auto __n = __last - __first;
*__d_first = *__first;
return __unseq_backend::__simd_walk_3(
__first + 1, __n - 1, __first, __d_first + 1,
[&__op](_ReferenceType1 __x, _ReferenceType1 __y, _ReferenceType2 __z) { __z = __op(__x, __y); });
}
template <class _ExecutionPolicy, class _ForwardIterator, class _OutputIterator, class _BinaryOperation,
class _IsVector>
_OutputIterator
__pattern_adjacent_difference(_ExecutionPolicy&&, _ForwardIterator __first, _ForwardIterator __last,
_OutputIterator __d_first, _BinaryOperation __op, _IsVector __is_vector,
/*is_parallel*/ std::false_type) noexcept
{
return __internal::__brick_adjacent_difference(__first, __last, __d_first, __op, __is_vector);
}
template <class _ExecutionPolicy, class _ForwardIterator1, class _ForwardIterator2, class _BinaryOperation,
class _IsVector>
_ForwardIterator2
__pattern_adjacent_difference(_ExecutionPolicy&& __exec, _ForwardIterator1 __first, _ForwardIterator1 __last,
_ForwardIterator2 __d_first, _BinaryOperation __op, _IsVector __is_vector,
/*is_parallel=*/std::true_type)
{
_PSTL_ASSERT(__first != __last);
typedef typename std::iterator_traits<_ForwardIterator1>::reference _ReferenceType1;
typedef typename std::iterator_traits<_ForwardIterator2>::reference _ReferenceType2;
*__d_first = *__first;
__par_backend::__parallel_for(
std::forward<_ExecutionPolicy>(__exec), __first, __last - 1,
[&__op, __is_vector, __d_first, __first](_ForwardIterator1 __b, _ForwardIterator1 __e) {
_ForwardIterator2 __d_b = __d_first + (__b - __first);
__internal::__brick_walk3(
__b, __e, __b + 1, __d_b + 1,
[&__op](_ReferenceType1 __x, _ReferenceType1 __y, _ReferenceType2 __z) { __z = __op(__y, __x); },
__is_vector);
});
return __d_first + (__last - __first);
}
} // namespace __internal
} // namespace __pstl
#endif /* _PSTL_NUMERIC_IMPL_H */