sycl::h_item#
template <int Dimensions>
class h_item;
The sycl::h_item class identifies an instance of a
group::parallel_for_work_item function object executing at each
point in a local sycl::range passed to a
parallel_for_work_item call or to the corresponding
parallel_for_work_group call if no sycl::range is passed to the
parallel_for_work_item call. It encapsulates enough information
to identify the work-item's local and global items according to the
information given to parallel_for_work_group (physical ids) as well
as the work-item's logical local items in the logical local range.
All returned item objects are offset-less. Instances of the
sycl::h_item class are not user-constructible and
are passed by the runtime to each instance of the function object.
Warning
Based on developer and implementation feedback, the hierarchical data parallel kernel feature is undergoing improvements to better align with the frameworks and patterns prevalent in modern programming.
As this is a key part of the SYCL API and we expect to make changes to it, we temporarily recommend that new codes refrain from using this feature until the new API is finished in a near-future version of the SYCL specification, when full use of the updated feature will be recommended for use in new code.
Existing codes using this feature will of course be supported by conformant implementations of this specification.
See also
SYCL Specification Section 4.9.1.6
Member functions#
get_global#
sycl::item<Dimensions, false> get_global() const;
Return the constituent global item representing the work-item’s position in the global iteration space as provided upon kernel invocation.
get_local#
sycl::item<Dimensions, false> get_local() const;
Return the same value as get_logical_local().
get_logical_local#
sycl::item<Dimensions, false> get_logical_local() const;
Return the constituent element of the logical local work-item’s
position in the local iteration space as provided upon the invocation
of the sycl::group::parallel_for_work_item.
If sycl::group::parallel_for_work_item was called without any logical
local range then the member function returns the physical local item.
A physical id can be computed from a logical id by getting the remainder
of the integer division of the logical id and the physical range:
get_logical_local().get() % get_physical_local.get_range() ==
get_physical_local().get().
get_physical_local#
sycl::item<Dimensions, false> get_physical_local() const;
Return the constituent element of the physical local work-item’s position in the local iteration space as provided (by the user or the runtime) upon the kernel invocation.
get_global_range#
sycl::range<Dimensions> get_global_range() const;
Return the same value as get_global().get_range().
size_t get_global_range(int dimension) const;
Return the same value as get_global().get_range(dimension).
get_global_id#
sycl::id<Dimensions> get_global_id() const;
Return the same value as get_global().get_id().
size_t get_global_id(int dimension) const;
Return the same value as get_global().get_id(dimension).
get_local_range#
sycl::range<Dimensions> get_local_range() const;
Return the same value as get_local().get_range().
size_t get_local_range(int dimension) const;
Return the same value as get_local().get_range(dimension).
get_local_id#
sycl::id<Dimensions> get_local_id() const;
Return the same value as get_local().get_id().
size_t get_local_id(int dimension) const;
Return the same value as get_local().get_id(dimension).
get_logical_local_range#
sycl::range<Dimensions> get_logical_local_range() const;
Return the same value as get_logical_local().get_range().
size_t get_logical_local_range(int dimension) const;
Return the same value as get_logical_local().get_range(dimension).
get_logical_local_id#
sycl::id<Dimensions> get_logical_local_id() const;
Return the same value as get_logical_local().get_id().
size_t get_logical_local_id(int dimension) const;
Return the same value as get_logical_local().get_id(dimension).
get_physical_local_range#
sycl::range<Dimensions> get_physical_local_range() const;
Return the same value as get_physical_local().get_range().
size_t get_physical_local_range(int dimension) const;
Return the same value as get_physical_local().get_range(dimension).
get_physical_local_id#
sycl::id<Dimensions> get_physical_local_id() const;
Return the same value as get_physical_local().get_id().
size_t get_physical_local_id(int dimension) const;
Return the same value as get_physical_local().get_id(dimension).