Struct melior::dialect::ods::tensor::ExtractSliceOperation

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

An extract_slice operation. Extract slice operation.

The “extract_slice” operation extract a tensor from another tensor as specified by the operation’s offsets, sizes and strides arguments.

The extract_slice operation supports the following arguments:

• source: the “base” tensor from which to extract a slice.
• offsets: tensor-rank number of offsets into the “base” tensor from which to extract the slice.
• sizes: tensor-rank number of sizes which specify the sizes of the result tensor type.
• strides: tensor-rank number of strides specifying subsampling in each dimension.

The representation based on offsets, sizes and strides support a partially-static specification via attributes specified through the static_offsets, static_sizes and static_strides arguments. A special sentinel value ShapedType::kDynamic encodes that the corresponding entry has a dynamic value.

After buffer allocation, the “extract_slice” op is expected to lower into a memref.subview op.

An extract_slice operation may additionally reduce the rank of the resulting tensor by removing dimensions that are statically known to be of size 1. This rank-reduction behavior is not required by the op semantics: this flexibility allows to progressively drop unit dimensions while lowering between different flavors of ops on that operate on tensors.

Verification vs Inference in the rank-reduced case

Note that there may be multiple ways to infer a resulting rank-reduced type. e.g. 1x6x1 could potentially rank-reduce to either 1x6 or 6x1 2-D shapes.

To disambiguate, the inference helpers inferCanonicalRankReducedResultType only drop the first unit dimensions, in order: e.g. 1x6x1 rank-reduced to 2-D will infer the 6x1 2-D shape, but not 1x6.

Verification however has access to result type and does not need to infer. The verifier calls isRankReducedType(getSource(), getResult()) to determine whether the result type is rank-reduced from the source type. This computes a so-called rank-reduction mask, consisting of dropped unit dims, to map the rank-reduced type to the source type by dropping ones: e.g. 1x6 is a rank-reduced version of 1x6x1 by mask {2} 6x1 is a rank-reduced version of 1x6x1 by mask {0} 1x2x1x4 is a rank-reduced version of 1x1x2x1x1x4x1 by mask {1, 4, 6} (remaining common 1 dimensions are matched eagerly)

Example:

// Rank-reducing extract_slice.
%1 = tensor.extract_slice %0[0, 0, 0][1, 16, 4][1, 1, 1] :
  tensor<8x16x4xf32> to tensor<16x4xf32>
%3 = tensor.extract_slice %2[%o0, 4, %o2][1, %sz1, 1][1, %st1, 1] :
  tensor<8x16x4xf32> to tensor<1x?xf32>

Implementations

impl<'c> ExtractSliceOperation<'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> ) -> ExtractSliceOperationBuilder<'c, Unset, Unset, Unset, Unset, Unset, Unset, Unset, Unset>

Creates a builder.

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

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

pub fn offsets(&self) -> Result<impl Iterator<Item = Value<'c, '_>>, Error>

pub fn sizes(&self) -> Result<impl Iterator<Item = Value<'c, '_>>, Error>

pub fn strides(&self) -> Result<impl Iterator<Item = Value<'c, '_>>, Error>

pub fn static_offsets(&self) -> Result<Attribute<'c>, Error>

pub fn set_static_offsets(&mut self, value: Attribute<'c>)

pub fn static_sizes(&self) -> Result<Attribute<'c>, Error>

pub fn set_static_sizes(&mut self, value: Attribute<'c>)

pub fn static_strides(&self) -> Result<Attribute<'c>, Error>

pub fn set_static_strides(&mut self, value: Attribute<'c>)

Trait Implementations

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

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

Converts to this type from the input type.

impl<'c> TryFrom<Operation<'c>> for ExtractSliceOperation<'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.