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Convert linalg to loops

convert_linalg_to_loops

LowerLinalgStructuredOpPattern

Bases: RewritePattern

Source code in xdsl/transforms/convert_linalg_to_loops.py 
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class LowerLinalgStructuredOpPattern(RewritePattern):
    @op_type_rewrite_pattern
    def match_and_rewrite(
        self,
        op: linalg.abstract_ops.LinalgStructuredOperation,
        rewriter: PatternRewriter,
    ) -> None:
        if op.res:
            raise NotImplementedError(
                f"lowering for {op.name} with tensor results not yet supported"
            )

        def insert_load(
            value_index: int,
            ind_vars: Sequence[SSAValue],
            rewriter: PatternRewriter,
            insertion_target: InsertPoint,
        ) -> SSAValue:
            value = op.operands[value_index]
            affine_map_attr = op.get_indexing_maps().data[value_index]
            if isinstance(value.type, MemRefType):
                indices = indices_for_map(
                    rewriter, insertion_target, affine_map_attr.data, ind_vars
                )
                load_op = memref.LoadOp.get(value, indices)
                rewriter.insert(load_op, insertion_target)
                return load_op.res
            else:
                return value

        ins_count = len(op.inputs)

        def insert_store(
            output_index: int,
            value: SSAValue,
            ind_vars: Sequence[SSAValue],
            rewriter: PatternRewriter,
            insertion_target: InsertPoint,
        ):
            value_index = ins_count + output_index
            destination = op.operands[value_index]
            affine_map_attr = op.get_indexing_maps().data[value_index]
            indices = indices_for_map(
                rewriter, insertion_target, affine_map_attr.data, ind_vars
            )
            store_op = memref.StoreOp.get(value, destination, indices)
            rewriter.insert(store_op, insertion_target)
            return store_op

        insertion_point = InsertPoint.before(op)
        rewrite_linalg_structured_to_loops(
            rewriter,
            op,
            insertion_point,
            create_loop_bounds(rewriter, insertion_point, op),
            op.get_indexing_maps().data,
            op.get_indexing_maps().data[-len(op.outputs) :],
            op.operands,
            op.outputs,
            op.body.block,
            insert_load,
            insert_store,
        )

match_and_rewrite(op: linalg.abstract_ops.LinalgStructuredOperation, rewriter: PatternRewriter) -> None

Source code in xdsl/transforms/convert_linalg_to_loops.py 
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@op_type_rewrite_pattern
def match_and_rewrite(
    self,
    op: linalg.abstract_ops.LinalgStructuredOperation,
    rewriter: PatternRewriter,
) -> None:
    if op.res:
        raise NotImplementedError(
            f"lowering for {op.name} with tensor results not yet supported"
        )

    def insert_load(
        value_index: int,
        ind_vars: Sequence[SSAValue],
        rewriter: PatternRewriter,
        insertion_target: InsertPoint,
    ) -> SSAValue:
        value = op.operands[value_index]
        affine_map_attr = op.get_indexing_maps().data[value_index]
        if isinstance(value.type, MemRefType):
            indices = indices_for_map(
                rewriter, insertion_target, affine_map_attr.data, ind_vars
            )
            load_op = memref.LoadOp.get(value, indices)
            rewriter.insert(load_op, insertion_target)
            return load_op.res
        else:
            return value

    ins_count = len(op.inputs)

    def insert_store(
        output_index: int,
        value: SSAValue,
        ind_vars: Sequence[SSAValue],
        rewriter: PatternRewriter,
        insertion_target: InsertPoint,
    ):
        value_index = ins_count + output_index
        destination = op.operands[value_index]
        affine_map_attr = op.get_indexing_maps().data[value_index]
        indices = indices_for_map(
            rewriter, insertion_target, affine_map_attr.data, ind_vars
        )
        store_op = memref.StoreOp.get(value, destination, indices)
        rewriter.insert(store_op, insertion_target)
        return store_op

    insertion_point = InsertPoint.before(op)
    rewrite_linalg_structured_to_loops(
        rewriter,
        op,
        insertion_point,
        create_loop_bounds(rewriter, insertion_point, op),
        op.get_indexing_maps().data,
        op.get_indexing_maps().data[-len(op.outputs) :],
        op.operands,
        op.outputs,
        op.body.block,
        insert_load,
        insert_store,
    )

ConvertLinalgToLoopsPass dataclass

Bases: ModulePass

Converts a linalg structured ops to perfectly nested loops.

Source code in xdsl/transforms/convert_linalg_to_loops.py 
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class ConvertLinalgToLoopsPass(ModulePass):
    """
    Converts a linalg structured ops to perfectly nested loops.
    """

    name = "convert-linalg-to-loops"

    def apply(self, ctx: Context, op: ModuleOp) -> None:
        PatternRewriteWalker(
            LowerLinalgStructuredOpPattern(),
            apply_recursively=False,
        ).rewrite_module(op)

name = 'convert-linalg-to-loops' class-attribute instance-attribute

apply(ctx: Context, op: ModuleOp) -> None

Source code in xdsl/transforms/convert_linalg_to_loops.py 
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def apply(self, ctx: Context, op: ModuleOp) -> None:
    PatternRewriteWalker(
        LowerLinalgStructuredOpPattern(),
        apply_recursively=False,
    ).rewrite_module(op)

materialize_loop_bound(rewriter: PatternRewriter, insertion_point: InsertPoint, operand: SSAValue[MemRefType], dim_index: int, dim_size: int) -> SSAValue

Create the value used as one loop upper bound.

If the memref dimension is dynamic, use memref.dim. If it is static, use an index constant.

Source code in xdsl/transforms/convert_linalg_to_loops.py 
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def materialize_loop_bound(
    rewriter: PatternRewriter,
    insertion_point: InsertPoint,
    operand: SSAValue[MemRefType],
    dim_index: int,
    dim_size: int,
) -> SSAValue:
    """
    Create the value used as one loop upper bound.

    If the memref dimension is dynamic, use `memref.dim`.
    If it is static, use an index constant.
    """

    if dim_size == DYNAMIC_INDEX:
        dim_index_op = arith.ConstantOp.from_int_and_width(dim_index, IndexType())
        rewriter.insert(dim_index_op, insertion_point)

        dim_op = memref.DimOp(operand, dim_index_op.result)
        rewriter.insert(dim_op, insertion_point)
        return dim_op.result

    else:
        const_op = arith.ConstantOp.from_int_and_width(dim_size, IndexType())
        rewriter.insert(const_op, insertion_point)
        return const_op.result

create_loop_bounds(rewriter: PatternRewriter, insertion_point: InsertPoint, op: linalg.abstract_ops.LinalgStructuredOperation) -> Sequence[SSAValue]

Build loop upper bounds for a linalg structured operation.

This lowering only supports buffer semantics, so bound sources must come from memref operands.

Source code in xdsl/transforms/convert_linalg_to_loops.py 
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def create_loop_bounds(
    rewriter: PatternRewriter,
    insertion_point: InsertPoint,
    op: linalg.abstract_ops.LinalgStructuredOperation,
) -> Sequence[SSAValue]:
    """
    Build loop upper bounds for a linalg structured operation.

    This lowering only supports buffer semantics, so bound sources must come
    from memref operands.
    """
    bounds: list[SSAValue] = []

    for operand, dim_index, dim_size in op.get_loop_bound_sources():
        if not isa(operand, SSAValue[MemRefType]):
            raise PassFailedException(
                "convert-linalg-to-loops requires buffer semantics; "
                "tensor operands must be bufferized to memrefs before lowering"
            )

        bounds.append(
            materialize_loop_bound(
                rewriter,
                insertion_point,
                operand,
                dim_index,
                dim_size,
            )
        )

    return bounds