Types of rocPRIM operations

A rocPRIM operation is a computation over a sequence of elements.

The elements of the sequence can be of any type and belong to any class. Template specialization optimizes the computations over data types.

The scope of an operation determines whether an operation is running at the thread, warp, block, or grid level.

The following tables provide a summary of the different types of operations and what they do.

Type	Operation	Description
Basic	Transform	Transform operations are device-level operations that apply a function to each element in the sequence. They’re equivalent to the map functional operation.
	Select	Select operations are device-level operations that select the first N elements in the sequence that satisfy a condition set by a selection mask or a predicate function.
	Unique	Unique operations are device-level operations that return only the first element from a group of similar consecutive elements.
	Histogram	Histogram operations are device-level operations that return a statistical distribution of the sequence.
Aggregation	Reduce	Reduce operations can run at the thread, warp, block, grid, or device level. They’re equivalent to the functional fold_left. Reduce runs in a pairwise manner over the sequence in multiple iterations, reducing the sequence until only one result remains.
	Scan	Scan is a cumulative version of reduce that returns the sequence of intermediate values.
Difference	Adjacent difference	Adjacent difference operations are device-level and block-level operations that compute the difference between either the current element and the next one in the sequence, or between the current element and the previous one in the sequence.
	Discontinuity	Discontinuity operations are block-level operations that find items in a sequence that don’t follow the sequence order.
Reordering	Sort	Sort operations are device-level, block-level, and warp-level operations that reorder a sequence based on item comparisons.
	Partial sort	Partial sort is a device-level operation that reorders a sequence by sorting it up to and including a given index.
	Nth element	Nth element is a device-level operation that inserts a value in its sorted position in the sequence.
	Exchange	The exchange operations are block-level and warp-level operations that transpose stripe arrangements to block arrangements and vice versa.
	Shuffle	Shuffle operations are block-level and warp-level operations that move items between warps or threads in order to share memory.
Partitioning	Partition	Partition operations are device-level operations that separate the sequence based on a selection predicate. The order of the items in the sequence that return true is retained.
Merging	Merge	Merge operations are device-level operations that merge two ordered sequence into one while preserving the order.
Data movement	Store	Store operations are block, warp, and thread level operations that store items in block or stripe arrangements in contiguous memory.
	Load	Load operations are block, warp, and thread level operations that load data stored in contiguous memory into a block arrangement.
	Memcpy	Memcopy operations are device-level operations that run multiple device-to-device memory copy operations as single batch operations.
Search	Find first of	Find first of is a device-level operation that searches the sequence for the first occurrence of any of the items in a given range of items.
	Find end	Find end is a device-level operation that finds the last occurrence of a series of items in the sequence.
	Adjacent find	Adjacent find is a device-level operation that searches for the first occurrence of two consecutive equal items.
	Search	Search is a device-level operation that searches the sequence for the first occurrence of a series of items.
	Search N	Search N is a device-level operation that searches the sequence for the first occurrence of a series of N items that are all equal to a given value.
	Binary search	Binary search is a device-level operation that does a binary search on a sorted range of inputs.
Miscellaneous	Run length encode	Run length encode operations are device-level operations that do device-wide encodings of runs of consecutive equal values.
	Run length decode	Run length decode operations are block-level operations that decode run length encoded arrays of items.
	Kernel config	Kernel config constructs are device-level constructs that set the grid and block dimensions as well as the algorithms to use for the store and load operations.