LateInitCallback

#include <poplar/LateInitCallback.hpp>

namespace poplar

Poplar classes and functions.

A VectorList is a list of vectors with a specific layout and with the usage semantics of a 2D vector.

A 1D vector must be laid out in a contiguous memory region. A 2D vector is a vector of 1D vectors. Each of these 1D vectors that make up a 2D vector is called a “sub-vector” for the remainder of this document. The elements of a 2D vector can be accessed by indexing the 2D vector along the outer and inner dimensions as A[outer][inner].

The following two categories of layouts are supported:

1. VectorListLayout::DELTANELEMENTS is a memory efficient 2D vector layout. For legacy systems VectorListLayout::DELTAN served a similar purpose. Each sub-vector must be laid out as a contiguous memory region but the sub-vectors may may not be laid out contiguous with respect to each other in memory. Each sub-vector may have a different length.

2. VectorListLayout::ONE_PTR and other VectorListLayout layouts that are prefixed by SCALED_PTR are for Poplar runtime use only.

Typedefs

template<typename T>
using LateInitCallback = std::function<T(const VertexEdgeInfo&)>

A callback function of this type can be specified for a field of a vertex, instead of specifying an initialisation value with setInitialValue.

Will be called after the graph has been built. Will be passed information about the vertex fields. Needs to return the value for the field.

struct VertexEdgeInfo

#include <LateInitCallback.hpp>

Data structure that will be passed to the callback used for ‘late initialisation’ for vertex fields.

Contains address information for the other (edge) vertex fields to allow the callback to appropriately initialise the ‘late init’ field itself.

Public Members

std::map<std::string, std::vector<StorageInfo>> storage

struct StorageInfo

Public Members

std::uint64_t startOffs

std::uint32_t len