include/oneapi/dpl/pstl/hetero/algorithm_impl_hetero.h - implementati…

…on of __pattern_find_if on __parallel_transform_reduce

include/oneapi/dpl/pstl/hetero/algorithm_impl_hetero.h

@@ -771,16 +771,44 @@ _Iterator
 __pattern_find_if(__hetero_tag<_BackendTag>, _ExecutionPolicy&& __exec, _Iterator __first, _Iterator __last,
                   _Pred __pred)
 {
-    if (__first == __last)
+    using _difference_type = typename ::std::iterator_traits<_Iterator>::difference_type;
+
+    const _difference_type __n = __last - __first;
+    if (__n == 0)
         return __last;
 
-    using _Predicate = oneapi::dpl::unseq_backend::single_match_pred<_ExecutionPolicy, _Pred>;
+    using _result_type = oneapi::dpl::__internal::tuple<bool, _difference_type>;
+    const auto __init = _result_type{false, __n};
 
-    return __par_backend_hetero::__parallel_find(
-        _BackendTag{}, ::std::forward<_ExecutionPolicy>(__exec),
-        __par_backend_hetero::make_iter_mode<__par_backend_hetero::access_mode::read>(__first),
-        __par_backend_hetero::make_iter_mode<__par_backend_hetero::access_mode::read>(__last), _Predicate{__pred},
-        ::std::true_type{});
+    // __counting_iterator_t - iterate position (index) in source data
+    using __counting_iterator_t = oneapi::dpl::counting_iterator<_difference_type>;
+
+    using _zipped_data_type = typename std::iterator_traits<decltype(oneapi::dpl::make_zip_iterator(
+        __first, __counting_iterator_t{0}))>::value_type;
+
+    __find_if_binary_reduce_op<_zipped_data_type, /*_IsFirst*/ std::true_type> __reduce_op;
+    __find_if_unary_transform_op<_zipped_data_type, _Pred> __transform_op{__pred};
+
+    using _Functor = unseq_backend::walk_n<_ExecutionPolicy, decltype(__transform_op)>;
+    using _RepackedTp = __par_backend_hetero::__repacked_tuple_t<_result_type>;
+
+    auto __keep_src_data =
+        oneapi::dpl::__ranges::__get_sycl_range<__par_backend_hetero::access_mode::read, _Iterator>();
+    auto __buf_src_data = __keep_src_data(__first, __last);
+
+    const __counting_iterator_t __counting_it_first{0}, __counting_it_last{__n};
+    auto __keep_counting_it =
+        oneapi::dpl::__ranges::__get_sycl_range<__par_backend_hetero::access_mode::read, __counting_iterator_t>();
+    auto __buf_counting_it = __keep_counting_it(__counting_it_first, __counting_it_last);
+
+    auto res =
+        oneapi::dpl::__par_backend_hetero::__parallel_transform_reduce<_RepackedTp, std::true_type /*is_commutative*/>(
+            _BackendTag{}, std::forward<_ExecutionPolicy>(__exec), __reduce_op, _Functor{__transform_op},
+            unseq_backend::__init_value<_RepackedTp>{__init}, // initial value
+            oneapi::dpl::__ranges::make_zip_view(__buf_src_data.all_view(), __buf_counting_it.all_view()))
+            .get();
+
+    return std::get<0>(res) ? __first + std::get<1>(res) : __last;
 }
 
 //------------------------------------------------------------------------