Struct melior::dialect::ods::sparse_tensor::ExpandOperation

pub struct ExpandOperation<'c> { /* private fields */ }

An expand operation. Expands an access pattern for insertion.

Performs an access pattern expansion for the innermost levels of the given tensor. This operation is useful to implement kernels in which a sparse tensor appears as output. This technique is known under several different names and using several alternative implementations, for example, phase counter [Gustavson72], expanded or switch array [Pissanetzky84], in phase scan [Duff90], access pattern expansion [Bik96], and workspaces [Kjolstad19].

The values and filled arrays must have lengths equal to the level-size of the innermost level (i.e., as if the innermost level were dense). The added array and count are used to store new level-coordinates when a false value is encountered in the filled array. All arrays should be allocated before the loop (possibly even shared between loops in a future optimization) so that their dense initialization can be amortized over many iterations. Setting and resetting the dense arrays in the loop nest itself is kept sparse by only iterating over set elements through an indirection using the added array, so that the operations are kept proportional to the number of nonzeros.

Note that this operation is “impure” in the sense that even though the results are modeled through SSA values, the operation relies on a proper side-effecting context that sets and resets the expanded arrays.

Example:

%values, %filled, %added, %count = sparse_tensor.expand %tensor
  : tensor<4x4xf64, #CSR> to memref<?xf64>, memref<?xi1>, memref<?xindex>

Implementations

impl<'c> ExpandOperation<'c>

pub fn name() -> &'static str

Returns a name.

pub fn as_operation(&self) -> &Operation<'c>

Returns a generic operation.

pub fn builder( context: &'c Context, location: Location<'c> ) -> ExpandOperationBuilder<'c, Unset, Unset, Unset, Unset, Unset>

Creates a builder.

pub fn values(&self) -> Result<OperationResult<'c, '_>, Error>

pub fn filled(&self) -> Result<OperationResult<'c, '_>, Error>

pub fn added(&self) -> Result<OperationResult<'c, '_>, Error>

pub fn count(&self) -> Result<OperationResult<'c, '_>, Error>

pub fn tensor(&self) -> Result<Value<'c, '_>, Error>

Trait Implementations

impl<'c> From<ExpandOperation<'c>> for Operation<'c>

fn from(operation: ExpandOperation<'c>) -> Self

Converts to this type from the input type.

impl<'c> TryFrom<Operation<'c>> for ExpandOperation<'c>

type Error = Error

The type returned in the event of a conversion error.

fn try_from(operation: Operation<'c>) -> Result<Self, Self::Error>

Performs the conversion.