[oneDPL][ranges][merge] support size limit for output; + __parallel_merge sycl pattern support

MikeDvorskiy · MikeDvorskiy · commit 75e133e5418e · 2024-11-28T19:02:55.000+01:00
diff --git a/include/oneapi/dpl/pstl/hetero/algorithm_ranges_impl_hetero.h b/include/oneapi/dpl/pstl/hetero/algorithm_ranges_impl_hetero.h
@@ -54,7 +54,7 @@ template <typename _BackendTag, typename _ExecutionPolicy, typename _Function, t
 void
 __pattern_walk_n(__hetero_tag<_BackendTag>, _ExecutionPolicy&& __exec, _Function __f, _Ranges&&... __rngs)
 {
-    auto __n = oneapi::dpl::__ranges::__get_first_range_size(__rngs...);
+    auto __n = std::min({__rngs.size()...});
     if (__n > 0)
     {
         oneapi::dpl::__par_backend_hetero::__parallel_for(_BackendTag{}, ::std::forward<_ExecutionPolicy>(__exec),
diff --git a/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_merge.h b/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_merge.h
@@ -142,7 +142,7 @@ struct __parallel_merge_submitter<_IdType, __internal::__optional_kernel_name<_N
     {
         const _IdType __n1 = __rng1.size();
         const _IdType __n2 = __rng2.size();
-        const _IdType __n = __n1 + __n2;
+        const _IdType __n = std::min<_IdType>(__n1 + __n2, __rng3.size());
 
         assert(__n1 > 0 || __n2 > 0);
 

Original file line number	Diff line number	Diff line change
`@@ -54,7 +54,7 @@ template <typename _BackendTag, typename _ExecutionPolicy, typename _Function, t`
`54`	`54`	`void`
`55`	`55`	`__pattern_walk_n(__hetero_tag<_BackendTag>, _ExecutionPolicy&& __exec, _Function __f, _Ranges&&... __rngs)`
`56`	`56`	`{`
`57`		`- auto __n = oneapi::dpl::__ranges::__get_first_range_size(__rngs...);`
	`57`	`+ auto __n = std::min({__rngs.size()...});`
`58`	`58`	`if (__n > 0)`
`59`	`59`	`{`
`60`	`60`	`oneapi::dpl::__par_backend_hetero::__parallel_for(_BackendTag{}, ::std::forward<_ExecutionPolicy>(__exec),`
Original file line number	Diff line number	Diff line change
`@@ -142,7 +142,7 @@ struct __parallel_merge_submitter<_IdType, __internal::__optional_kernel_name<_N`
`142`	`142`	`{`
`143`	`143`	`const _IdType __n1 = __rng1.size();`
`144`	`144`	`const _IdType __n2 = __rng2.size();`
`145`		`- const _IdType __n = __n1 + __n2;`
	`145`	`+ const _IdType __n = std::min<_IdType>(__n1 + __n2, __rng3.size());`
`146`	`146`
`147`	`147`	`assert(__n1 > 0 \|\| __n2 > 0);`
`148`	`148`